JP2020076308A - Bit holder with shortened nose - Google Patents

Abstract

To provide a bit holder that minimizes a space between a bottom end of one bit holder block and a tip of a bit holder block adjacent thereto so that bit assemblies are mounted on a drum in much closer proximity to one another for use with more bit assemblies on a single drum.SOLUTION: By combining a bit holder 22 having a body portion, a generally cylindrical hollow shank that hangs axially from a bottom of the body portion, and an outer surface of the shank that tapers radially outward of the shank, a base mounting portion, a device receiving portion on a side opposite to a base surface, and a base block bore, which is adapted to receive the shank of the bit holder, the retention force between the bit holder shank and the base block bore is increased.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to bit assemblies for road milling machines, mining machines and trenching machines, and more particularly to bit holders and / or bits with a shortened front end. Regarding sleeves.

  In recent years, the removal of materials from hard soil has been carried out by mechanisms for achieving the removal of such materials, whether in highway reconstruction, trench digging operations, or longwall mining operations and other mining operations. We have seen many improvements. In order to reduce the downtime of such material removal devices, various improvements have been made to the bit assembly that defines the endpoint at which the device separates the surface material from the underlayer or ground. This end point, where the material removal device contacts the surface of the material to be removed, has traditionally been a bit with a pointed tip, a bit holder to which the bit can be attached or integrated, and a bit / bit. It consists of a series of bit assemblies including a bit holder block to which the holder base is attached. The bit holder block is mounted either on an endless chain or chain plate system or on a rotating drum.

  Currently, this bit assembly is most commonly used in rotating drums, where a number of such assemblies are mounted on the drum in either a V-shape or a helix. Such recent improvements have been found in US Pat. No. 6,371,567 and US Pat. No. 6,585,326, which disclose a threaded shank with a nut to secure the bit holder to the bit holder block. By this, it is no longer necessary to hold the bit holder or the intermediate parts of the bit assembly on the bit holder block. This improvement includes a hollow shank with a slot cut axially at its distal end, which shank is pushed into a hole in the bit holder block, with the distal end of the shank having the shank of the bit holder and the bit holder. Radial compression with sufficient radial force between the holes in the block keeps the bit holder attached to the bit block during use.

  Eliminating the lock nut or snap ring from the distal end of the bit holder shank facilitated removal of the bit holder from the bit holder block by passing the bit holder through the bottom of the bit holder block. Further, the tungsten carbide chip bit can be removed from the bit holder by punching the bid holder outward from the bottom of the hole in the bit holder block.

  Another improvement of the bit assembly is the introduction of diamond tip bits or combined bits / holders. The hardened bit tip can be formed of an artificial PCD material that is embedded in the core or base to form a coating on the tip of the bit / holder, or an industrial powder diamond material. By introducing this very hard material at the tip of the bit cutting assembly, in some cases a tungsten carbide bit mounted in a bit holder, which in turn is mounted in a bit holder block, is used. Has been replaced by a single bit / bit holder combination that has a longer service life than the three conventional tungsten carbide tip combinations. It should also be noted that the diamond tip bit can also be utilized with existing bit holders and bit blocks if desired.

  In the case of tungsten carbide tip bits, the bit preferably has the ability to rotate within the bit holder to disperse the wear characteristics of the bit during use. However, in order to extend the useful life of the diamond tip surface removal device, the tip no longer needs to be rotatable.

  Another improvement in the material removal process is a conventional surface cutting device with a spiral mounted bit assembly, which is conventionally positioned spirally or V-shaped across the drum with 5/8 inch axial center spacing. There is also a use of a micro-cutting device in which the distance between the tips of the bits is a center line of 0.200 inch with respect to the center-axis distance between the bits. Micro-cutting not only removes the material achieved by normal cutting, but also flattens parts of the road's uneven surface, or smoothes the road surface or stretches for repaving. It is also used to remove the top of the road by, for example, 1 inch or 2 inches. This can extend the life of the road surface and save costs.

  To use more bit assemblies on a single drum, while sometimes using about 900 such bit assemblies on a 46-54 inch diameter drum, the bit assemblies are much more Since it is mounted on the drum in an orientation close to, it is necessary to minimize the space between the lower end of one bit holder block and the tip of the adjacent bit holder block. This reduction in space between adjacent bit blocks has traditionally provided access to the bottom of the bit holder block for ejecting the bit holder or any combination of bits / holders from the bit holder block. Will be even more difficult than. The structure that increases the abutment distance between the front end of the bit assembly and the back of the adjacent bit assembly can provide more space for maintenance personnel to replace the bit, holder, or combined bit / holder.

  The present disclosure relates generally to road milling machines, miners, and bit assemblies for excavators. One embodiment of the teachings herein is a shank having a body portion including a body axial length, and a shank having a shank length greater than the body axial length, the shank having a substantially axial depending from a bottom of the body portion. A bit holder including a hollow cylindrical shank and an outer surface of a first portion of the shank that is adjacent the distal end of the shank and tapers radially outwardly as it extends toward the distal end. is there. Another embodiment of the teachings herein is a body portion having a body axial length, a shank having a shank length greater than the body axial length, the shank having a substantially axial extension from a bottom of the body portion. A bit holder having a hollow cylindrical shank and an outer surface of a first portion of the shank adjacent the distal end of the shank and tapering radially outward as it extends toward the distal end. A base mounting portion having a base surface, a device receiving portion integrally extending from the base mounting portion opposite to the base surface, and a base block bore extending through the device receiving portion for receiving the shank of the bit holder. A base block having a base block bore, and a combined bit holder and base block.

  These and other aspects of the disclosure are disclosed in the following detailed description of the embodiments, the appended claims, and the accompanying drawings.

Various features, advantages, and other applications of the device will become more apparent with reference to the following detailed description and drawings. Like reference numerals refer to like parts throughout the several views. It is emphasized that, according to common practice, the various features of the drawings are not drawn to scale.
On the contrary, the dimensions of the various features are arbitrarily expanded or reduced for clarity.
1 is a side view of a first embodiment of a bit assembly constructed in accordance with practice of the present disclosure. FIG. 2 is a bottom view of the bit assembly shown in FIG. 1 configured in accordance with embodiments of the present disclosure. FIG. 2 is a front view of the bit assembly shown in FIG. 1 configured in accordance with an embodiment of the present disclosure. FIG. 2 is a rear view of the bit assembly shown in FIG. 1 configured in accordance with an embodiment of the present disclosure. FIG. 2 is an exploded perspective view of the bit assembly shown in FIG. 1 constructed in accordance with an embodiment of the present disclosure. FIG. FIG. 6 is a rear 3/4 perspective view of the bit holder shown in FIG. 5 configured in accordance with an embodiment of the present disclosure. FIG. 7 is a side view of the bit holder shown in FIGS. 5 and 6 constructed in accordance with implementations of the present disclosure. FIG. 7 is an exploded view of a second embodiment of a bit assembly of the present disclosure including a diamond tip combined bit / holder constructed in accordance with an embodiment of the present disclosure. FIG. 9 is a rear 3/4 perspective view of the base of the combined bit / holder shown in FIG. 8 constructed in accordance with practice of the present disclosure. FIG. 9 is a side view of a base for the combined bit / holder shown in FIG. 8 constructed in accordance with practice of the disclosure. 2 is a detailed side view showing an enlarged rear access of the bit holder shown in FIG. 1 constructed in accordance with an embodiment of the present disclosure. FIG. 8 is a side view of the third embodiment of the bit holder shown in FIG. 7 with the shank distal end including an inverted taper configured in accordance with practice of the disclosure. FIG. 13 is a rear 3/4 perspective view of the third embodiment of the inverted taper bit holder shown in FIG. 12 constructed in accordance with an embodiment of the present disclosure. It is a rear 3/4 perspective view of the 1st modification of 3rd Embodiment of the bit holder which has the reverse taper similar to FIG. However, it includes a tapered annular upper shank portion above the inner end of the slot of the shank and below the tire portion of the bit holder body, constructed in accordance with practice of the disclosure. A side perspective view of a combined bit / holder of a fourth embodiment including thereon a diamond tip integrally formed with a holder body mounted to the first embodiment of a bit holder block constructed according to embodiments of the present disclosure. It is a figure. The bottom surface 3 / of the first embodiment bit assembly shown in FIG. 1 disclosing an additional access space adjacent the bottom of the first embodiment of a bit holder block constructed according to embodiments of the present disclosure. FIG. 4 is a perspective view. FIG. 9 is an exploded perspective view of a fifth embodiment of a bit holder and a second embodiment of a bit holder block configured according to embodiments of the present disclosure. FIG. 8 is an exploded side view of a fifth embodiment of a bit holder and a second embodiment of a bit holder block, constructed according to embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 6A is a side view of a fifth embodiment of a bit holder constructed in a second embodiment of a bit holder block constructed in accordance with embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 9 is an exploded perspective view of a sixth embodiment of a bit holder and a third embodiment of a bit holder block configured according to embodiments of the present disclosure. FIG. 9 is an exploded side view of a sixth embodiment of a bit holder and a third embodiment of a bit holder block constructed in accordance with embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 9A is a side view of a sixth embodiment of a bit holder assembled in a third embodiment of a bit holder block configured in accordance with embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 8 is an exploded perspective view of a fifth embodiment of a bit holder and a third embodiment of a bit holder block configured according to embodiments of the present disclosure. FIG. 9 is an exploded side view of a fifth embodiment of a bit holder and a third embodiment of a bit holder block constructed in accordance with embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 9A is a side view of a fifth embodiment of a bit holder constructed in a third embodiment of a bit holder block constructed in accordance with embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 11 is an elevational view of a seventh embodiment of a bit holder according to embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 27 is a cross-sectional view of the seventh embodiment of the bit holder taken along the line AA of FIG. 26 according to an embodiment of the present disclosure. FIG. 13 is a perspective view of a seventh embodiment of a bit holder according to an embodiment of the present disclosure. FIG. 29 is a cross-sectional view of the seventh embodiment of the bit holder taken along the center line BB of FIG. 28 according to an embodiment of the present disclosure. FIG. 16 is a perspective view of a first side surface of an eighth embodiment of a bit holder according to an embodiment of the present disclosure. FIG. 16 is a perspective view of a second side surface of an eighth embodiment of a bit holder according to an embodiment of the present disclosure. FIG. 13 is an elevational view of an eighth embodiment of a bit holder according to an embodiment of the present disclosure, showing invisible internal elements in dotted lines. FIG. 32 is a partial cross-sectional view of the eighth embodiment of the bit holder along the centerline CC of FIG. 31, according to embodiments of the disclosure. FIG. 16 is a perspective view of a first side surface of a ninth embodiment of a bit holder according to an embodiment of the present disclosure. FIG. 16 is a perspective view of a second side surface of a ninth embodiment of a bit holder according to an embodiment of the present disclosure. FIG. 10 is an elevational view of a ninth embodiment of a bit holder according to embodiments of the present disclosure, showing invisible internal elements in dotted lines. FIG. 36 is a partial cross-sectional view of the ninth embodiment of a bit holder taken along the center line DD of FIG. 35 according to an embodiment of the present disclosure. FIG. 27 is an exploded view of a bit assembly according to an embodiment of the present disclosure, showing an elevation view of the bit, a cross-sectional view of the seventh embodiment of the bit holder taken along line AA of FIG. 26, and a fourth view of the bit holder block. 3 shows a cross-sectional view of an embodiment. Incorporated into the cross-sectional view of the seventh embodiment of the bit holder, i.e., into the cross-sectional view of the fourth embodiment of the bit holder block, taken along line AA of FIG. 26, in accordance with an embodiment of the present disclosure. FIG. 39 is an elevational view of the bit, showing the assembled bit assembly of FIG. 38. FIG. 13 is an elevational view of a seventh embodiment of a bit holder according to an embodiment of the present disclosure, showing the configuration of the seventh embodiment of the bit holder when incorporated into the fourth embodiment of the bit holder block. FIG. 41 is a cross-sectional view of the seventh embodiment of the bit holder taken along line EE of FIG. 40 according to embodiments of the disclosure, the seventh implementation of the bit holder when incorporated into the fourth embodiment of the bit holder block. The configuration of the form is shown.

  1-4, 8 and 16, a first embodiment of a completed bit assembly 20 constructed in accordance with the present disclosure is a first embodiment of a bit holder block 21, a bit holder 22 and a bit 23. including. As previously mentioned, for micro-milling operations, sometimes up to 900 of these assemblies are wrapped around the outside of a hollow cylindrical drum (not shown), typically 46-54 inches in diameter. It is attached in a V shape or a spiral shape. Also, the bottom 24a of the base 24 of the bit holder block 21 of the bit assembly 20 can be attached to an endless chain or chain and plate system or drum (not shown) for grooving or mining operations.

<Bit Assembly of First Embodiment>
Each bit assembly 20 comprises a first embodiment of a bit holder block 21 having a base 24 and a bit holder receiving part or bit / holder receiving part 25. In this embodiment, the bit holder receiving portion 25 is generally cylindrical and extends from the base 24 portion as previously described. A bit block 21 constructed in accordance with the present disclosure includes an axially shortened annular bit holder receiving portion 25, which may be either a bit holder 22 or a bit / holder (26a, 26 in Figures 8 and 15). It is received in a bit holder block bore 27 positioned in the center of the block 21. The shortened axial length of the generally annular bit holder receiving portion 25 is close to 1.5 inches in length for a nominal diameter of 1.5 inches (FIG. 7). The ratio of the bit holder shank diameter D, ie the bit holder receiving position, to its length L is approximately a 1: 1 ratio.

  As most clearly shown in FIG. 11, the shortened shank can use an improved construction that allows the bit holder to be removed from or secured to the bit holder block 21. The bit holder block bore 27 includes an enlarged (one side 0.030 inch) upper shoulder portion 27a having an axial depth of about 1/4 to 3/8 inch. The remaining portion of the bit block bore 27 may be straight cylindrical or have an unlocked taper, preferably one degree on each side. The shortened portion of the bit holder block / bit holder receiver is most clearly shown in FIGS. 1 and 16 and is approximately 1 1/2 inch in length. The shortened bit block bore 27 receives the shortened bit holder shank 28 of the bit holder 22 as shown in FIGS. 5, 6, 7, 12, 13, 14. As shown in FIG. 4 and FIG. 16, by mounting the shortened shank, the recess 30 for adding access to the base 29 (FIG. 9) of the bit holder shank 28 and the base of the bit 23 are provided. Provided, the back of the hollow bit holder receiving portion 25 is provided with an additional access space 30 of more than 1 inch. This is better enabled by driving the bit holder 22 out of the bit holder block bore 27 from the bottom of the bit holder block bore 27 with a driving rod or other removal tool (not shown).

  The bit holder block 21 to which the base 24 is attached is similar to a conventionally known one in that it has a substantially rectangular bottom portion 24a in which a pair of attachment holes 24b and 24c are formed. The bottom 24a may be slightly curved to fit on the outside of a rotating drum (not shown). The base 24 may extend slightly from its bottom wall 24a, ultimately forming a pair of triangular sides 31, 32 and a pointed front that slopes downwardly and outwardly from the top ridge 39. Thereby deflecting the material loosened up by the tip of the bit 23 attached to the bit holder 22 and the body. At the top of the bit holder block, as shown most clearly in FIG. 5, is a bit holder base block mounting portion 25 having a substantially annular structure with a bore 27 penetrating in the center, which is an upper enlarged portion. 27a, the upper enlargement 27a may be cylindrically shaped or may have a non-locking taper for fitting the bit holder 22 as shown in FIG. ..

  As mentioned above, the remainder or bottom of the bit holder block bore 27 may be cylindrical or untapered, and currently preferably matches the distal taper of the bit holder shank (or It may have a one-degree, non-locking taper on each side (as will be discussed in more detail below).

  FIG. 16 shows a first embodiment of a bit assembly 20 that appears when mounted on a rotating drum (not shown) in an upside down position, where a bit holder 22 is utilized utilizing a drive punch (not shown). Can be pulled out of the bit holder block bore. Or a smaller drive pin can be used to drive the bit out of the bit mounting bore of the bit holder.

  As shown in FIG. 16, the base 24 of the bit holder block 21 and the recess 30 in which the bit holder block bore 27 extends are used to gain access to the base 24 of the bit holder block 21. , Smooth shaped so that crushed stones, cement or concrete particles, or hard soil (not shown) that may collect in the base 24 and recess 30 can be more easily removed therefrom. As shown in FIG. 3, the foremost surface of the bit holder block 21 can be cut away to form a pair of opposing substantially vertical wall portions 33, 34, which wall portions 33, 34 allow adjacent bits to be adjacent. Space is added to attach the block to the drum or endless chain. Therefore, a plurality of bit holder blocks 21 can be mounted in close proximity to each other, especially for use in micro-cutting operations. In a normal bit assembly attached to a drum for the purpose of cutting a road surface, the distance between adjacent bit assembly bit chips 23a is more conventionally 0.625 inches in the axial direction. At a spacing of 0.200 inches in the axial direction. The width and length of the bit holder block is important to ensure 0.200 inch spacing.

<Details of bit holder>
<First Exemplary Embodiment of Bit Holder>
In addition to the preceding figures, Figures 5, 6 and 7 disclose detailed views of the first embodiment bit holder 22 shown in assembled form in Figures 1-4, 16. The bit holder 22 includes a top body portion 35 and a bottom shank portion 28 (both substantially annular). The top or body portion 35 of the bit holder 22 includes a flat upper annular surface 36 having a generally cylindrical profile. The upper annular surface 36 is substantially the same as or very close to the large diameter of the bit 23 or the bit washer 37. The bit washer 37 is mounted within the central bit bore 38 of the bit holder 22 that extends axially through the bit holder body portion 35 and the shank 28, and on the upper surface 36 thereof.

  The central portion 40 of the bit holder body portion 35 extends outwardly from the generally cylindrical upper bit attachment portion 41 and is convex in this embodiment, but may be convex, conical or concave. .. However, generally, the material is separated by the bit tip 23a and deflects the material outward as it moves axially and outwardly along the body of the bit 23, bit holder 22 and bit holder block 21 ( deflect).

  As the central portion 40 of the first embodiment of the bit holder 22 expands, it stops at the joint between the central portion and the base 42. The base 42, or what is referred to as the "tire portion" of the cylindrical bit holder 22, is a cylindrical segment having an axial height of approximately 1/2 inch and a nominal diameter of 25/8 inch. Is. The tire portion 42 terminates in an annular, radially extending flange 43 that forms the bottom of the body of the bit holder. The bottom portion is adapted to be fitted adjacent to the top annular surface 44 of the bit holder receiving portion 27 of the bit holder block 21 described above. This adjacent fit allows the tire portion 42 to be spatially associated with the upper surface 44 of the bit holder block 21 when the shank 28 is fully installed within the bit holder block bore 27. The number of critical surfaces between the two parts can be reduced. Inside the radially extending flange 43 is a U-shaped undercut 45. The undercut 45 contacts the shank 28 of the bit holder 22 at its inner end. The U-shaped groove 45 provides a portion for relieving the stress between the main body portion 35 of the bit holder 22 and the shank 28 without sharpening the edge portion.

  The bit holder shank 28 extends axially from the U-shaped groove 45. The top of the shank 28 directly adjacent to the body is an enlarged portion 46 having an axial length of about 1/4 to 3/8 inch, which fits with the enlarged top bore portion 27a of the bit holder block bore 27 described above. Fit together. In the first embodiment, the enlarged portion 46 has a substantially cylindrical shape. For shanks with a nominal diameter of 1 1/4 to 1 3/4 inch, the interference fit with the bit holder block bore is about 0.001-0.003 inch. Immediately adjacent to the axially outer side of the enlarged portion 46 on the top of the shank 28 is a constriction 47 having a length of about 1/8 to 5/8 inch, which is tapered in axial dimension or It has a cylindrical shape. In this first embodiment, the distal portion 48 of the shank 28, which is approximately 1/2 to 15/8 inch, is provided with a chamfer 50 along with a bottom flange 51 that extends radially and defines the bottom of the shank 28 of the bit holder. It is a non-locking taper extending toward.

  In this first exemplary embodiment of the bit holder 22, the central portion 47 and the distal portion 48 of the shank 28 are of a pair of one slot 52 extending to the outer distal end of the shank and one internal slot 53. Slots are included, both slots 52, 53 being axially oriented and preferably 180 degrees apart. The distal portion 48 of the shank, which has a nominal diameter of 1 1/2 inch, is cylindrical with an interference dimension that is approximately 0.005-0.030 inch larger than the bottom of the adjacent bit holder bore 27, or is unlocked. Being tapered (details described below), these slots allow this shank 28 to engage the bit holder block bore 27 in an amount greater than that found in the published solid body interference table. The shank 28 collapses radially when it is interference fit. This interference can be referred to as the differential interference with the bit holder block bore as it increases as it moves from the top of the distal portion 48 to its bottom. This interference is increased until it produces a radial force of 5000 to 30,000 pounds that keeps the bit holder 22 within the bit holder block 21 when the bit assembly 20 is in heavy use.

  Experiments and observations have shown that in previous embodiments of the present disclosure using a matching bit holder shank / bit holder block bore taper, the majority of the interference fits occur at the top of the slotted taper portion of the shank. It was The longer the slot portion in the shank, the less bending force is at the distal end of the shank and the lesser the holding force on the distal end of the shank.

  By reducing the angle of the tapered distal portion 48 near the shank end of the bit holder 22, more force is exerted radially near the distal end of the shank, resulting in shank 28 and bit holder block bore 27. And a margin with a greater difference is given. This makes it possible to obtain a sufficient holding force with a shank shorter than previously known.

  If the cylindrical or non-locking taper portion 48 of the bit holder shank 28 increases the convergence with the bit holder block bore 27 towards its bottom flange 51, then an outwardly tapered shank / Cylindrical block bores, cylindrical shanks / inwardly tapered block bores, inwardly tapered bores / less inwardly tapered shanks, inwardly tapered bores / Many combinations, such as outwardly tapered shanks, can be designed to provide the necessary holding force between the bit holder and the bit block bore. Unlocked tapers generally extend from 0.01 to 3.5 degrees per side, or up to a total of 7 degrees in diameter.

  With reference to FIGS. 1, 3, 4 and 5, this first embodiment bit assembly 20 has a body with a generally conical brazed carbide tip 54 located at the upper end. A generally cylindrical shape that in this first embodiment includes a bit 23 having a portion, an annular flange (not shown) at the bottom of the body portion, and an inwardly extending space for mounting a spring steel C-shaped retainer 56. It is concluded with the shank of. In use, this type of bit is rotated in the bit holder bore 38. Normally, the bit holder 22 does not rotate within the bit holder block bore 27.

<Second Exemplary Embodiment of Bit Holder>
Referring to Figures 8, 9 and 10, a second embodiment of a bit assembly 20a of the present disclosure is shown and described. This second embodiment includes the same bit holder block base 24 as shown in the first embodiment. However, the second embodiment also includes a single bit / bit holder 26a having a base 57 with a body portion 58 from which a shank 60 extends axially. The body portion 58 and shank 60 are substantially the same as the body portion 35 and shank 28 of the first embodiment of the present disclosure. However, the uppermost surface of the central portion of the body 58 includes an annular recess 61 from which a tapered annular tip 62 extends axially. The combination of the outer surface of the tapered tip 62 and the annular recess 61 provides a base surface for mounting the annular tungsten carbide ring 63. The annular tungsten carbide ring 63 is a hollow frustoconical shape that tapers from its bottom to its top, and fits snugly over the annular tip 62 of the body 58. The upper annular tip 62 of the main body 58 includes a central recess 62a, in which a recess for receiving the reverse taper member 64 is formed. The reverse taper member 64 is slidably fitted and retained in the recess 62a at the tip of the upper portion 62a of the main body, that is, the base 58. A diamond-coated bit tip 66 having a substantially conical tip is mounted in the recess formed in the top of the inverse taper member 64. As with the first embodiment of the bit assembly 20 of the present disclosure, all of these members are brazed within their respective recesses to fit a substantially single bit / bit that fits within the bit holder block bore 27. The holder 26a is formed.

  The diamond tip 66 on top of the bit / holder 26a has a substantially longer service life than the tungsten carbide tip. Therefore, this single piece does not need to rotate due to the long service life provided by the diamond-coated tip 66. The shortened shank 60 of the base 58 of the bit / holder 26a fits into the bit holder block bore 27 similar to the shank of the holder in the first embodiment and facilitates withdrawal therefrom as in the first embodiment. ing.

  The construction of the top of the bit / holder is generally found in Applicant's US Pat. No. 6,739,327, which forms the top of the bit removable from its respective bit holder.

<Third exemplary embodiment of bit holder>
12, 13 and 14, a third embodiment of the bit holder 70 is shown. This third embodiment of the bit holder 70 also includes an upper body portion 71 and a lower shank 72 portion. A first modification of the bit holder 73 of the third embodiment is shown in FIG. 14 and will be described in more detail below. In each, the upper body portion 71 of the bit holder is substantially the same as the upper body portion of the bit holder 22 of the first embodiment shown in FIGS. 1, 3, 5, 6, 7. Further, the upper portion 74 and the central portion 75 of the shank 72 of this embodiment are the same as those of the first embodiment of the bit holder 22, specifically, those shown in FIGS. However, the difference between the first embodiment of the bit holder 22 and this third embodiment of the bit holder 70 is that the special disengagement of the distal portion 76 of the shank 72 (as shown in FIGS. 12-14). Seen in the reverse taper of the stop. This non-locking size inverse taper fits into either the cylindrical shape of the bit holder block bore 27, or a regular taper, preferably one degree on one side, shown most clearly in FIG. The reverse taper provides a substantially different interference fit between a portion of the distal taper 76 and the bit holder block bore 27 over only a portion of the length of the shank 72 and the bore 27.

  Applicants have found that in a prior art quick change bit holder / bit holder block combination having the same cylindrical or tapered distal portion and bottom, respectively, the closer the distal end of the shank is, the greater the diameter the bit holder shank will experience. It has been found that the directional force becomes smaller and a greater radial force is generated as it approaches the upper end of the open end slot. Therefore, a slight difference or reversal in the distal portion of the shank diameter of the bit holder results in radial forces on the bottom of the bit holder block bore and radial forces along the entire length of the distal portion of the shank. Tend to be equal. Applicants refer to this as a differential interference to distinguish it from the known prior art.

  This slight difference in taper (different interference) can be along the shape's spectrum. In the present disclosure, the bottom of the shank with constant taper has an axial length of about 1/2 to 15/8 inch. In the prior art bit holder / bit holder block bore combinations, each had an equal unlocking taper, preferably less than 1 degree per side. In this third embodiment, the bit holder shank 72 may preferably have a 1 degree outward taper for each of the bit holder block bores 27 having a 1 degree inward taper or cylindrical configuration. .. Similarly, the bit holder shank 72 may be cylindrical with respect to the non-locking taper of the bit holder block bore 27. The mutual convergence of the tapered / cylindered surfaces (different interference) may be different as discussed in the first embodiment.

  Of course, if it is desired to apply more force towards the bottom of the distal portion 76 of the shank 72, a greater degree of unlocking taper differential is desirable. The degree of taper difference is limited only by the limit of the unlocked taper and by the diameter of the shank end and the diameter of the top opening of the bore in the bit holder block. It is necessary to be able to position the bit holder shank in the center of the bit holder block bore 27 and insert it there.

  The non-locking taper is about 3 1/2 degrees on one side, or 7 degrees in total. In the illustrated embodiment, the shortest distal portion of the shank is provided. The larger the different taper mentioned above towards the limit of the unlocked taper, the longer the distal portion or bottom of the shank and the length of the bit holder block bore will be to obtain the total holding force required. Must.

  This limited difference in the substantially annular contact surface between the distal end of the shank and the bottom of the bit holder block bore (differential interference) causes the bit holder to move a short distance within the bit holder block. Since it can be removed by itself, it is easier to insert and remove the bit holder from the bit holder block. The unlocked size is preferably here an unlocked reverse taper of ½ degree or more on one side at a nominal 1 1/2 inch diameter of the shank 72, but the unlocked size is approximately 5000. Sized to fit the bottom of the bit holder block bore, but over a shorter axial distance of the contact surface, while having a interference exerting a radial force of from 30,000 to 30,000 pounds. One or two slots may be used. A single slot exerts more radial force than two slots. A slotted reverse taper shank 72 and a generally cylindrical upper expansion 74 of the shank with a standard 0.001-0.003 interference for the upper expansion 27a of the bit holder block bore 27. In combination, in this embodiment the bit holder 70 is substantially mounted within the bit holder block bore 27 during use.

  FIG. 14 shows a first modification of the bit holder 73 of the third embodiment, in which the upper portion 77 of the bit holder shank 72 is not cylindrical but has a tapered shape with a locking or non-locking taper. Yes, and fits into a complementary shaped taper in the top of the bit holder block bore (not shown).

<Fourth Exemplary Embodiment of Bit / Holder>
FIG. 15 discloses a fourth embodiment of the bit / holder 26 of the present disclosure, providing a combined bit / holder that fits the improved bit holder block 21 shown in the previous embodiment. .. The bit / holder 26 is diamond coated, or contains a hard diamond tip, such that the bit / holder is a one-piece construction that fits into the bit holder block bore 27, similar to the previous embodiments. , Including a generally conical tip 80. The top of the bit / holder or bolster 81 behind the tip includes a generally convex shaped member made of tungsten carbide having a recess 82 in the top thereof in which the diamond tip 80 is located. Brazed. Similarly, the enlarged base 83 of the bolster 81 is brazed to the top of the body portion 86 of the bit / holder 26.

  The body portion 86 is an outwardly and axially extending body portion 86 that includes a recessed counterbore or a slightly concave upper surface 85 to which a bolster is brazed, in this embodiment a concave surface contour. Or it can be convex. The lower portion 86 of this central recess terminates in a generally cylindrical tire or base portion 87. The base portion 87 is similar to the base portion shown in the previous embodiment, except that its distal end includes a portion 88 that extends inward at 45 degrees to a flat annular surface. This 45 degree tapered portion 88 provides a generally fork-shaped tool (not shown) that can be used in place of the drift pin previously described, with access to withdraw the bit / holder from the bit holder block bore. To do. Similarly, in this embodiment, the bit / holder 26 of the fourth embodiment may be turned upside down as in the first embodiment shown in FIG. Therefore, the improvement of recessing and shortening the rear of the bit holder block allows for a wider access to the bit / holder shank (not shown), thus allowing the bit / holder shank to be located in the bit holder block bore 27. A pull-out punch that pushes axially outward can be used more easily. Again, in this fourth embodiment, the diamond tip substantially improves the bit / holder life, so the bit / holder 26 does not need to rotate, but like the previous embodiment, 5000 to 30,000 pounds. The radial force may be fixedly mounted within the bit holder block bore 27.

<Fifth Exemplary Embodiment of Bit Holder>
17-19, there is shown a fifth embodiment of a bit holder 100 and a second embodiment of a bit holder block or base block 102. In this exemplary embodiment, the bit holder 100 includes a nose portion or bit holder body 104 and a generally cylindrical hollow shank 106 that depends axially from the bottom of the nose portion 104 and is approximately 2 3/4 inch. It is a standard length shank bit holder. This design can be successfully implemented with shanks of varying lengths. Nose portion 104 is, in this exemplary implementation of the fifth exemplary embodiment, a generally annular shape and a frustoconical first portion 108 that extends axially from upper surface 110, such as a flat annular upper surface, and the like. It includes a frustoconical second portion 112 that extends axially from the first portion 108 and a generally cylindrical tire portion 114 that extends axially from the second portion 112. A chamfer 116 extends from the bottom of the tire portion 114 to the back flange 118, and the rear flange 118 can be generally annular. The back flange 118, one on each side of the back flange 118, is a pair of horizontal slots 120-120 (one of which is shown in FIGS. 17-19) substantially perpendicular to the longitudinal axis of the bit holder 100. Is included). The horizontal slots 120-120 are inserted between the base of the nose portion 104 of the bit holder 100 and the base block 102 of the second embodiment or the block 202 of the third embodiment (FIGS. 23-25). It is designed to receive the teeth of one of the two forks. The shank 106 of the bit holder 100 is inserted into the base block 102 of the second embodiment or the block 202 of the third embodiment, and is held by a radially outward force during use. Other base block configurations can be used without departing from this design concept.

  The shank 106 includes an elongated first slot 122 that extends axially upward or forward from a distal end 124 of the shank 106, such as a generally annular distal end. It extends to the upper end portion 126 near the upper or front end of 106. In this exemplary embodiment, shank 106 also includes an inwardly oriented second slot 128 (FIG. 17) located approximately 180 degrees around annular shank 106 from first slot 122. In this exemplary embodiment, this second slot 128 is parallel to the first slot 122 and has a rear end 130 (FIGS. 17-19) that is inwardly adjacent to the distal end 124 of the shank 106; 19 is an internal slot having an upper end 126 of one slot 122 and a front end 132 (FIGS. 18 and 19) that is substantially longitudinally and axially aligned.

  In this exemplary embodiment, shank 106 also includes a lower or first outwardly tapered portion 134 that extends axially from stepped shoulder 136 adjacent distal end 124 of shank 106. The stepped shoulder 136 increases from axially extending distal end 138 of the shank 106 adjacent the distal end 124 of the shank 106 to the lower outward taper portion 134, or increases in steps. The lower outward taper portion 134 extends upwardly or axially from the stepped shoulder 136 of the shank 106 and terminates the slot 122 approximately midway longitudinally. The shank 106 also includes an annular shoulder 140 that separates the lower outward taper portion 134 from the second taper portion 142, the second taper portion 142 from the shoulder 140 being generally adjacent to the top of the shank 106. That is, to the front ends 126, 132 of the slots 122, 128. An annular shoulder 140 is located between the first lower outward taper portion 134 and the second taper portion 142. The diameter of the annular shoulder 140 decreases as the annular shoulder 140 extends axially from the first outwardly tapered portion 134 to the second tapered portion 142, i.e., decreases in steps. The generally cylindrical top 144 of the shank 106 extends from a location adjacent the second tapered portion 142 toward a rear flange 118 that shows the base or bottom of the nose portion 104 of the bit holder 100. The top of the shank 106 may include a rounded joint 146 (FIGS. 18 and 19) between the top 144 of the shank 106 and the rear flange 118 of the nose portion 104 of the bit holder 100, which joint is shown. The portion 146 is provided to avoid sharp corners that can be areas where stress cracking begins. In other embodiments, the shank 106 may include different configurations, for example, the lower portion 134 and / or the upper portion 142 of the shank 106 may be generally cylindrical, outwardly tapered, inwardly tapered, slightly stretched ( It may include a draw angle or a slight draft angle.

A central bore 148 extends axially from the top surface 110 of the bit holder 100 to the distal end 138 of the shank 106. The central bore 148 is adapted to receive a shank of the bit (not shown). When the shank is attached to the bore 150 of the base block 102 (FIGS. 17 and 18) or the bore 250 of the base block 202 (FIGS. 23 and 24), the central bore 148 and slots 122, 128 allow for approximately C of the shank 106. The V-shaped annular side wall contracts radially. (In some applications, the slot 122 itself may be used.)
The second embodiment of the base block 102 includes a base mount 152, which includes a base 154. The base 154 can be attached to the outside of a drum (not shown) or attached to a stand or riser attached to the drum. A stand or riser is a component of a road milling machine or similar machine designed in the shape of a drum. The front portion or the front portion of the base attachment portion 152 may include a pair of shoulder portions 156 to 156 inclined rearward. A generally annular and / or cylindrical bit holder receiving portion 158 is adjacent to the base mounting portion 152 that holds the base block 102 to the drum or a stand or riser disposed on the drum, from the front surface 160 of the receiving portion 158 to the base block. A central bore 150 extends axially to a rear end 162 of the 102. Bore 150 includes countersink 164 adjacent front surface 160 and outwardly tapered portion 166 adjacent rear end 162. The bore 150 of the base block 102 is adapted to receive the shank 106 of the bit holder 100, as shown in FIG. The bore 148 of the bit holder 100 is adapted to receive the shank (not shown) of the bit. Alternatively, the bore 250 of the base block 202 is adapted to receive the shank 106 of the bit holder 100, as shown in FIG.

<Sixth Exemplary Embodiment of Bit Holder>
20-22, a sixth embodiment of a bit holder 200 and a third embodiment of a bit holder block or base block 202 are shown. The bit holder 200 includes a nose portion or bit holder body 204 and a generally cylindrical hollow shank 206 depending axially from the bottom of the nose portion 204. The shank 206 of the sixth embodiment bit holder 200 is shorter than the standard bit holder generally about 2 3/4 inch long shank, and in this exemplary embodiment, the shank 206 of the bit holder 200. The length of shank 206 is approximately nominally 13/4 inch. This design can be successfully implemented with shanks of varying lengths. Nose portion 204 is, in the exemplary implementation of this sixth exemplary embodiment, a generally annular shape, such as a frustoconical first axially extending top surface 210, such as a flat annular top surface. Portion 208, a frustoconical second portion 212 that extends axially from the first portion 208, and a generally cylindrical tire portion 214 that extends axially from the second portion 212. A chamfer 216 extends from the bottom of the tire portion 214 to the back flange 218. The back flange 218 can be generally annular. The back flange 218 includes a pair of horizontal slots 220-220, one of which is shown in FIGS. 20-22, one on each side of the back flange 218 and substantially perpendicular to the longitudinal axis of the bit holder 200. The horizontal slots 220-220 are adapted to receive one bifurcating fork tooth that can be inserted between the base of the nose portion 204 of the bit holder 200 and the base block 202 of the third embodiment. The shank 206 of the bit holder 200 is inserted into the base block 202 of the third embodiment and is retained by a radially outward force during use. Other base block configurations can be used without departing from this design concept.

  The shank 206 extends from a distal end 224 of the shank 206, eg, a generally annular distal end, axially upward or forward, to an upper end 226 near the upper or front end of the shank 206. Slot 222. In another embodiment, the shank 206 may also include an inwardly oriented second slot (not shown) located approximately 180 degrees around the annular shank 206 from the first slot 222. This second slot may be parallel to the first slot 222 and is inwardly adjacent the rear end (not shown) of the distal end 224 of the shank 206 and the upper end 226 of the first slot 222. Is an internal slot having a front end (not shown) that substantially coincides with the longitudinal and axial directions.

  In this exemplary embodiment, shank 206 also includes a lower or first tapered portion 228 that extends axially from step shoulder 230 adjacent distal end 224 of shank 206. The stepped shoulder 230 increases as it axially extends from the distal end 232 of the shank 206 adjacent the distal end 224 of the shank 206 to the lower tapered portion 228, ie, increases in steps. The lower tapered portion 228 extends upwardly or axially from the stepped shoulder 230 of the shank 206 and terminates the slot 222 approximately midway in the longitudinal direction. The shank 206 also includes an annular shoulder 234 that separates the lower tapered portion 228 from the upper or second tapered portion 236. The second taper portion extends from the shoulder 234 to approximately just adjacent the top of the shank 206. The annular shoulder 234 is disposed between the first tapered portion 228 and the second tapered portion 236. The diameter of the annular shoulder 234 decreases as the annular shoulder 234 extends axially from the first tapered portion 228 to the second tapered portion 236, ie, decreases in steps. A generally cylindrical top 238 of the shank 106 extends from a position adjacent the second tapered portion 236 toward a rear flange 218 that shows the base or bottom of the nose portion 204 of the bit holder 200. The top of the shank 206 can include a rounded joint 240 (FIGS. 21 and 22) between the top 238 of the shank 206 and the back flange 218 of the nose portion 204 of the bit holder 200. 240 is provided to avoid sharp corners that can be areas where stress cracking begins. In other embodiments, the shank 206 can include different configurations, for example, the lower portion 228 and / or the upper portion 236 of the shank 206 can be generally cylindrical, outwardly tapered, slightly draw angle or slightly. A draft angle can be included.

  The central bore 242 extends axially from the upper surface 210 of the bit holder 200 to the distal end 224 of the shank 206. The central bore 242 is adapted to receive a shank of a bit (not shown). When the shank is mounted within the bore 250 (FIGS. 20 and 21) of the base block 202, the central bore 242 and the slot 222 radially contract the generally C-shaped annular sidewall of the shank 206.

  The base block 202 includes a base or mounting portion 244 and a shortened front end or bit holder receiving portion 246 opposite the base 248 of the base block 202. The shortened front end or receiver 246 may have an annular or substantially cylindrical shape, or in the first variation of the third embodiment of the base block 202, the shortened front end or receiver 246 may be , May include opposing flat sides (not shown). The base 248 can be flat or slightly concave to accommodate a drum or additional mounting plate, stand, or riser to which multiple base blocks can be mounted. In this exemplary embodiment, the shortened receiver 246 has a length from the front surface 252 of the base block 202, which is also the front surface of the shortened receiver 246, to a rear surface 254 of the shortened receiver 246. 1 1/2 inch or more, which adds about 7/8 inch access space from the rear surface 254 of the shortened receiving portion 246 to the rear portion 256 of the base block 202. The receiver 246 includes a base block bore 250 that is symmetrical with the shank 206 along the centerline and, in this exemplary embodiment, has a median diameter of nominally 1 1/2 inch. In this exemplary embodiment, bore 250 is tapered and includes countersink 258 adjacent front surface 252 of base block 202. In other embodiments, the bore 250 may be cylindrical, generally cylindrical, inwardly tapered, outwardly tapered, or any combination thereof.

  In this embodiment, the rear surface 254 of the shortened receiver 246 includes a semi-cylindrical beveled slot 260 in the radially outermost portion of the base block bore 250. The slanted slots 260 add space for working out a bit (not shown) with a drift pin or tool (not shown). The portion 262 of the base block 202 includes an extension of the arcuate portion 264 of the bore 250, which extends from the rear surface 254 of the shortened receiving portion 246 to a position adjacent the rear portion 256 of the base block 202. In this exemplary embodiment, arcuate portion 264 of tapered bore 250 has a radius that is reduced from the radius of bore 250. The bore 250 of the base block 202 is adapted to receive the shank 206 of the bit holder 200 and the bore 242 of the bit holder 200 is adapted to receive the shank of a bit (not shown). Alternatively, the bore 250 of the base block 202 is adapted to receive the shank 106 of the fifth embodiment of the bit holder 100, as shown in FIGS.

<Seventh Exemplary Embodiment of Bit Holder>
26-29, a seventh embodiment of the bit holder 300 is shown. Bit holder 300 includes a nose portion or bit holder body 302 and a generally cylindrical hollow shank 304 depending axially from the bottom of nose portion 302. The shank 304 of the bit holder 300 of the seventh embodiment is shorter than the standard bit holder generally about 2 3/4 inch long shank, and in this exemplary implementation, the bit holder 300. The length of the shank 304 is approximately 13/4 inch nominal. This design can be successfully implemented with shanks of varying lengths. Nose portion 302 is, in this exemplary implementation of the seventh exemplary embodiment, a generally annular shape, such as a frustoconical portion 306 extending axially from upper surface 308, such as a flat annular upper surface, and a cone. A substantially cylindrical tire portion 310 extending axially from the trapezoidal portion 306. A chamfer 312 extends from the bottom of the tire portion 310 to the back flange 314, and the rear flange 314 can be generally annular.

  The shank 304 extends from the distal end 318 of the shank 304, eg, a generally annular distal end, in an axially upward or forward direction to an upper terminal end 320 near the upper or front end of the shank 304. Includes slot 316. In another embodiment, the shank 304 can also include a second slot (not shown) oriented inwardly located about 180 degrees around the annular shank 304 from the first slot 316. This second slot may be parallel to the first slot 316 and is rearwardly inwardly adjacent the distal end 318 of the shank 304 (not shown) and the upper end 320 of the first slot 316. Is an internal slot having a front end (not shown) that substantially coincides with the longitudinal and axial directions.

  In this illustrated embodiment, shank 304 also includes a lower or first outwardly tapered portion 322 adjacent distal end 318 of shank 304, as shown by interior angle A in FIG. The lower outward taper portion 322 extends upwardly or axially from a location adjacent the distal end 318 of the shank 304 and terminates the slot 316 approximately longitudinally intermediately. The shank 304 also includes an annular shoulder 324 that separates the lower outwardly tapered portion 322 from the upper or second portion 326. The second portion extends from shoulder 324 to a position generally adjacent the top of shank 304. An annular shoulder 324 is disposed between the first outward taper portion 322 and the second portion 326. The diameter of the annular shoulder 324 decreases as the annular shoulder 324 extends axially from the second portion 326 to the first outwardly tapered portion 322, ie, decreases in steps. The second portion 326 of the shank 304 extends from a location adjacent the annular shoulder 324 toward the rear flange 314 which represents the base or bottom of the nose portion 302 of the bit holder 300. The top of the shank 304 may include a rounded joint 328 between the second portion 326 of the shank 304 and the back flange 314 of the nose portion 302 of the bit holder 300, which joint 328 may be stressed. It is provided to avoid sharp corners which can be areas where cracks start. In other embodiments, the shank 304 can include different configurations, for example, the lower portion 322 and / or the upper portion 326 of the shank 304 can be generally cylindrical, outward taper, inward taper, slight extension angle ( It may include a draw angle or a slight draft angle.

  The central bore 330 extends axially from the upper surface 308 of the bit holder 300 to the distal end 318 of the shank 304 and includes a countersink 332 adjacent the upper surface 308 of the bit holder 300. In this illustrated embodiment, central bore 330 tapers outwardly as it extends from approximately the middle of second portion 326 to distal end 318 of shank 304. In this exemplary embodiment, the taper of bore 330 is set at an angle B from centerline 334 of central bore 330. The interior angle A of the outwardly tapered portion 322 is an acute angle that is greater than the centerline 334 of the central bore 330. In this exemplary embodiment, interior angle A and angle B may be about the same value. The central bore 330 is adapted to receive a shank of the bit (not shown). When the shank is mounted in the bore 250 (FIGS. 20 and 21) of the base block 202, the central bore 242 and the slot 222 radially contract the generally C-shaped annular side wall of the shank 206 to the distal side of the shank 206. The ends 318 are generally and / or generally cylindrical. The shank 304 of the bit holder 300 is inserted and held by radial outward force during use. Other base block configurations can be used without departing from this design concept.

<Eighth Exemplary Embodiment of Bit Holder>
30-33, an eighth embodiment of the bit holder 400 is shown. The bit holder 400 includes a nose portion or bit holder body 402 and a generally cylindrical hollow shank 404 depending axially from the bottom of the nose portion 402. The shank 404 of the bit holder 400 of the eighth embodiment is shorter than a standard bit holder, generally a standard shank of about 2 3/4 inch in length, and in this exemplary embodiment, the bit holder 400. The length of the shank 404 is approximately nominally 13/4 inch. This design can be successfully implemented with shanks of varying lengths. The nose portion 402, in this exemplary implementation of the eighth exemplary embodiment, is generally annular in shape, with a frustoconical portion 406 extending axially from a top surface 408, such as a flat annular top surface, and a frustoconical shape. A generally cylindrical tire portion 410 extending axially from the portion 406. The chamfer 412 extends from the bottom of the tire portion 410 to the rear flange 414, which can be generally annular.

  The shank 404 extends from a distal end 418 of the shank 404, such as a generally annular distal end, axially upward or forward, to an upper end 420 near the upper or front end of the shank 404. Includes one slot 416. In another embodiment, shank 404 may also include an inwardly oriented second slot (not shown) located approximately 180 degrees around annular shank 404 from first slot 416. This second slot may be parallel to the first slot 416 and is inwardly adjacent to the distal end 418 of the shank 404, and a rear end (not shown) and an upper end 420 of the first slot 416. Is an internal slot having a front end (not shown) that substantially coincides with the longitudinal and axial directions.

  In this exemplary embodiment, shank 404 also includes a lower or first tapered portion 422 that extends axially from step shoulder 424 adjacent distal end 418 of shank 404. The stepped shoulder 424 increases as it axially extends from the distal end 424 of the shank 404 adjacent the distal end 418 of the shank 404 to the lower tapered portion 422, or increases in steps. The lower tapered portion 422 extends upwardly or axially from the stepped shoulder 424 of the shank 404 and terminates the slot 416 approximately midway longitudinally. The shank 404 also includes an annular shoulder 428 that separates the lower tapered portion 422 from the upper or second tapered portion 430. The annular shoulder 428 is disposed between the first tapered portion 422 and the second tapered portion 430. The diameter of the annular shoulder 428 decreases as the annular shoulder 428 extends axially from the first tapered portion 422 to the second tapered portion 428, ie, decreases in steps. The second tapered portion 430 of the shank 404 extends from a location adjacent the annular shoulder 428 toward the rear flange 414 which represents the base or bottom of the nose portion 402 of the bit holder 400. The top of the shank 404 may include a rounded joint 432 between the second tapered portion 430 of the shank 404 and the back flange 414 of the nose portion 402 of the bit holder 400, the joint 432 being stressed. It is provided to avoid sharp corners which can be areas where cracks start. In other embodiments, the shank 404 can include different configurations, for example, the lower portion 422 and / or the upper portion 430 of the shank 404 are generally cylindrical, outwardly tapered, inwardly tapered, slightly stretched ( It may include a draw angle or a slight draft angle.

  The central bore 434 extends axially from the upper surface 408 of the bit holder 400 to the distal end 418 of the shank 404 and includes a countersink 436 adjacent the upper surface 408 of the bit holder 400. In the illustrated embodiment, the central bore 434 tapers outwardly as it extends from approximately midway through the second portion 428 to the distal end 418 of the shank 404, similar to the taper shown in FIG. .. The central bore 434 is adapted to receive a shank of the bit (not shown). When the shank is installed in the bore of the base block, the central bore 434 and slot 416 radially contract the generally C-shaped annular sidewall of the shank 404, causing the distal end 418 of the shank 404 to generally and / or near. Or it is generally cylindrical and is held by radial outward forces during use. Other base block configurations can be used without departing from this design concept.

<Ninth Exemplary Embodiment of Bit Holder>
34 to 37, a ninth embodiment of the bit holder 500 is shown. The bit holder 500 includes a nose portion or bit holder body 502 and a generally cylindrical hollow shank 504 depending axially from the bottom of the nose portion 502. The shank 504 of the bit holder 500 of the ninth embodiment is shorter than the standard bit holder generally about 2 3/4 inch long shank of the standard bit holder, and in this exemplary implementation, the bit holder 500. Shank 504 has a nominal length of approximately 13/4 inch. This design can be successfully implemented on shanks of various lengths. The nose portion 502 is, in this exemplary implementation of the illustrated ninth embodiment, a generally annular shape, with a frustoconical portion 506 extending axially from the upper surface 508, such as a flat annular upper surface, A generally cylindrical tire portion 510 extending axially from the frustoconical portion 506. A chamfer 512 extends from the bottom of the tire portion 510 to the back flange 514. The rear flange 514 can be generally annular.

  The shank 504 extends from the distal end 518 of the shank 504, eg, a generally annular distal end, in an axially upward or forward direction to an upper terminal end 520 near the upper or front end of the shank 504. 516 is included. In another embodiment, the shank 502 may also include an inwardly oriented second slot (not shown) located about 180 degrees around the annular shank 504 from the first slot 516. .. This second slot may be parallel to the first slot 516 and at the rear end (not shown) inwardly adjacent the distal end 518 of the shank 504 and the upper end 52 of the first slot 516. And an inner slot having a front end (not shown) substantially coincident with the longitudinal and axial directions.

  In the illustrated embodiment, shank 504 also includes a lower or first outwardly tapered portion 522 that extends axially from a stepped shoulder 524 adjacent distal end 518 of shank 504. The stepped shoulder 524 becomes larger, or progressively larger, as it axially extends from the distal end 526 of the shank 504 adjacent the distal end 518 of the shank 504 to the lower outward taper 522. The lower outward taper portion 522 extends upwardly or axially from the stepped shoulder 524 of the shank 504 and terminates the slot 516 approximately midway longitudinally. The shank 504 also includes an annular shoulder 528 that separates the lower outwardly tapered portion 522 from the upper or second tapered portion 530. The second tapered portion 530 extends from the shoulder 528 to a position generally adjacent the top of the shank 504. An annular shoulder 528 is located between the first outwardly tapered portion 522 and the second tapered portion 530. The diameter of the annular shoulder 528 decreases, or decreases in steps, as the annular shoulder 528 extends axially from the first outer tapered portion 522 to the second tapered portion 530. The generally cylindrical top 532 of the shank 504 extends from a position adjacent the second tapered portion 530 toward the back flange 514 which represents the base or bottom of the nose portion 502 of the bit holder 500. The top of the shank 504 can include a rounded joint 534 (FIGS. 34, 36, and 37) between the top 532 of the shank 504 and the back flange 514 of the nose portion 502 of the bit holder 500. The joint 534 is provided to avoid sharp corners that can be areas where stress cracks begin. In other embodiments, the shank 504 can include different configurations, eg, the lower portion 522 and / or the upper portion 530 of the shank 504 are generally cylindrical, outwardly tapered, inwardly tapered, slightly stretched ( It may include a draw angle or a slight draft angle.

  The central bore 536 extends axially from the upper surface 508 of the bit holder 500 to the distal end 514 of the shank 504 and includes a countersink 538 adjacent the upper surface 508 of the bit holder 500. In the illustrated embodiment, the central bore 536 tapers outwardly as it extends generally from the middle of the second portion 530 to the distal end 518 of the shank 504, similar to the taper shown in FIG. .. Central bore 536 is adapted to receive a shank of the bit (not shown). When the shank is mounted within the base block bore, the central bore 536 and the slot 516 radially contract the generally C-shaped annular sidewall of the shank 504, causing the shank 504 and bore 536 to be generally and / or generally. It becomes a (generally) cylindrical shape and is held by a radially outward force during use. Other base block configurations can be used without departing from this design concept.

<Seventh Exemplary Embodiment of Bit Holder and Fourth Exemplary Embodiment of Base Block>
38-41, there is shown a seventh embodiment of a bit holder 300 and a fourth embodiment of a base block 600 as described above. The fourth embodiment of the base block 600 includes a base mounting portion 602 including a base 604 and a generally annular and / or cylindrical bit holder receiving portion 606. The base 64 is flat, as shown, or slightly concave, to fit a cylindrical drum (not shown) or to attach to a stand or riser attached to the drum. The bit holder receiving portion 606 is adjacent to the base mounting portion 602 that holds the base block 600 on the drum. The receiving portion 606 includes a central bore 608 that extends axially from a front surface 610 of the receiving portion 606 to a recess 612 adjacent the base 604 of the base mounting portion 602 of the base block 600. Bore 608 includes countersink 614 adjacent front surface 610. As shown in FIG. 39, the bore 608 of the base block 600 is designed to receive the shank 304 of the bit holder 300, and the shank 304 of the bit holder 300 is inserted into the bore 608 so that the bore 608 faces radially outward during use. Held by force. The bore 330 of the bit holder 300 is adapted to receive the shank 616 of the bit 618. Other base block configurations can be used without departing from this design concept.

  In use, when the shank is mounted in a base block bore, such as bore 608 of base block 600, as shown in FIGS. Contracts in the radial direction. As shown in FIG. 40, the slotted shank 304 can be reshaped to provide a more complete surface fit or contact between the shank 304 and the bore 608 of the base block 600. As a result, bit holder 300 remains snugly mounted within bore 608 of base block 600, extending the useful life of bit assembly 620 (FIG. 39). Referring to FIG. 41, after the bit holder 300 is inserted into the bore 608 of the base block 600, the central bore 330 tapers outwardly toward the distal end 318 (J, K, and L of FIG. 41). ), With a generally cylindrical and / or annular shape.

  As used in this application, the term "or" or "or" is intended to mean an inclusive "or / or" rather than an exclusive "or / or". That is, unless specified otherwise, or clear from context, "X comprises A or / or B" is intended to mean any natural inclusive permutation. That is, when X includes A, X includes B, or X includes both A and B, "X includes A or B" is satisfied in any of the above cases. Furthermore, "X comprises at least one of A and B" is intended to mean any natural inclusive permutation. That is, when X includes A, X includes B, or X includes both A and B, “X includes at least one of A and B” is satisfied in any of the above examples. Be done. As used in this application and the appended claims, the articles "a" and "an" generally refer to "one or more," unless specified otherwise or clear from the context that the singular is intended. Should be construed as meaning. Furthermore, the use of the verb “one implementation” or “one implementation” throughout is not intended to mean the same embodiment, aspect or implementation, unless so stated.

  Although this disclosure has been described with reference to particular embodiments and measurements, it is not intended that this disclosure be limited to the disclosed embodiments and measurements, but, on the contrary, covers various modifications and equivalent arrangements. It is intended. The scope should be given its broadest interpretation so as to encompass all such modifications and equivalent structures as permitted by law.

US Pat. No. 6,371,567 US Patent No. 6,585,326

Claims (25)

A body portion having a length in the body axial direction,
A shank having a shank length longer than the axial length of the main body, which is a substantially cylindrical hollow shank that hangs axially from the bottom of the main body portion,
An outer surface of the first portion of the shank adjacent the distal end of the shank and tapering radially outward as it extends toward the distal end;
A bit holder equipped with. A slot through the sidewall of the shank, the slot extending from the distal end of the shank,
The bit holder according to claim 1. Further comprising an upper end of the slot disposed adjacent a front end of the shank,
The bit holder according to claim 2. Further comprising a slot through a sidewall of the shank, the slot extending from a rear position adjacent the distal end of the shank to a front position adjacent the front end of the shank.
The bit holder according to claim 1. Further comprising a bore extending axially from the front end of the body portion to the distal end of the shank.
The bit holder according to claim 1. Further comprising a length of the shank including one of a standard length and a shortened length shorter than the standard length,
The bit holder according to claim 1. The standard length is nominally 2 3/4 inches and the shortened length is nominally 1 3/4 inches.
The bit holder according to claim 6. Further comprising a portion of the bore having a taper that is radially outward as it extends toward the distal end of the shank.
The bit holder according to claim 5. Adjacent to the first portion, and further comprising a second portion of the shank, having a taper that is radially inward as it extends toward the first portion.
The bit holder according to claim 1. A body portion having a length in the body axial direction,
A shank having a shank length longer than the axial length of the main body, the hollow shank having a substantially cylindrical shape axially depending from a bottom portion of the main body portion, and the shank adjacent to the distal end of the shank. An outer surface of the first portion of the shank that tapers radially outwardly as it extends toward the distal end,
A bit holder having
A base mounting portion having a base surface,
A device receiving portion integrally extending from the base mounting portion on the side opposite to the base surface, and a base block bore extending through the device receiving portion, the base adapted to receive the shank of the bit holder. Block bore,
A base block having
Combined bit holder and base block with. A slot through the sidewall of the shank, the slot extending from the distal end of the shank.
A combined bit holder and base block according to claim 10. Further comprising an upper end portion of the slot disposed adjacent a front end of the shank,
The combined bit holder and base block of claim 11. A slot through the sidewall of the shank, the slot extending from a rear position adjacent the distal end of the shank to a front position adjacent the front end of the shank.
A combined bit holder and base block according to claim 10. A bit holder bore axially extending from a front end of the body portion to the distal end of the shank;
A combined bit holder and base block according to claim 10. Further comprising a length of the shank including one of a standard length and a shortened length shorter than the standard length,
A combined bit holder and base block according to claim 10. The standard length is nominally 2 3/4 inches and the shortened length is nominally 1 3/4 inches.
The combined bit holder and base block of claim 15. Further comprising a portion of the bit holder bore having a taper that is radially outward as it extends toward the distal end of the shank.
The combined bit holder and base block of claim 14. Further comprising an axial length of the device receiving portion that is shorter than the length of the base attachment portion,
A combined bit holder and base block according to claim 10. The base mounting portion includes an extension of an arcuate portion of the base block bore that extends beyond the rear portion of the device receiving portion to a position adjacent to the rear portion of the base mounting portion.
A combined bit holder and base block according to claim 18. The extension of the arcuate portion of the base block bore forms an interference fit with the first portion of the shank, the shank length being nominally 2 3/4 inch.
A combined bit holder and base block according to claim 19. The device further includes an inclined slot surrounded by a side wall of the device receiving portion and extending inward from a rear portion of the device receiving portion to a position connecting a front portion of the device receiving portion and a rear portion of the device receiving portion,
A combined bit holder and base block according to claim 18. A second portion of the shank adjacent the first portion and having a taper that is radially inward as it extends toward the first portion;
A combined bit holder and base block according to claim 10. The base block bore has an axial length of about 1 1/2 inch and a nominal diameter of 1 1/2 inch.
A combined bit holder and base block according to claim 18. The length of the shank is based on the diameter of the bore,
The bit holder according to claim 5. The length of the shank is based on the diameter of the bit holder bore,
The combined bit holder and base block of claim 14.

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