US3802244A

US3802244A - Apparatus and method for pointing wire

Info

Publication number: US3802244A
Application number: US00319664A
Authority: US
Inventors: A Jackman
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-29
Filing date: 1972-12-29
Publication date: 1974-04-09
Anticipated expiration: 1991-04-09

Abstract

Apparatus for use in pointing wire or rod comprising a die holder having a generally wedge shaped upwardly opening die receiving recess containing a pair of split wedge shaped wire forming dies. The dies move in sliding engagement with walls of the die holder toward each other and into working engagement with a wire positioned therebetween when pulling force is applied to the wire in an axial direction and relative to the die holder whereby to reduce the cross sectional area of an elongated portion of the wire spaced from its ends. Reversal of the direction of force applied to the wire causes the dies to separate or move out of engagement with the wire. A point is formed on the wire by cutting it transversely of its axis to expose a free end of the elongated portion.

Description

United States Patent [191 J ackman Apr. 9,1974

APPARATUS AND METHOD FOR POINTING WIRE Arthur E. Jackman, 756 W. Main St., New Britain, Conn. 06051 Filed: Dec. 29, 1972 Appl. No.: 319,664

Inventor:

US. Cl 72/275, 72/285, 72/402 Int. Cl. B21c 5/00 Field of Search 72/185, l86, 275, 285,

References Cited UNITED STATES PATENTS 9/l96l Ewart H 72/402 l2/l955 Ware v 72/285 9/l908 Bray et al. 83/318 Primary Examiner-Lowell A. Larson Attorney, Agent, or Firm-McCormick, Paulding & Huber [57] ABSTRACT Apparatus for use in pointing wire or rod comprising a an elongated portion of the wire spaced from its ends.

Reversal of the direction of force applied to the wire causes the dies to separate or move out of engagement with the wire. A point is formed on the wire by cutting it transversely of its axis to expose a free end of the elongated portion.

11 Claims, 7 Drawing Figures APPARATUS AND METHOD FOR POINTING WIRE BACKGROUND OF THE INVENTION This invention relates in general to methods and apparatus for forming wire, rod and like material and deals more particularly with an improved apparatus and method for use in pointing a wire or rod in preparation for a drawing operation or the like.

Heretofore, various devices and methods have been provided for forming a point or elongated portion of reduced cross-sectional area on a rod or wire to facilitate insertion thereof into a drawing die. If the rod or wire to be pointed has sufficient column strength, a point may be formed thereon by forceably inserting a free end portion thereof into a suitable forming die. However, the aforesaid method cannot be utilized when the wire or rod to be pointed is made from a relatively soft material or otherwise lacks sufficient column strength to resist buckling upon forceable insertion into a die. Various power operated apparatus have been provided for pointing wire or rod by swaging or turning to displace or remove material, however, such apparatus is usually relatively expensive and requires periodic tool maintenance. Accordingly, it is the general aim of this invention to provide a method and apparatus for use in pointing wire, the apparatus being of simple, rugged construction for low-cost manufacture, durability, and relatively maintenance free service.

SUMMARY OF THE INVENTION In accordance with the present invention, an improved method and apparatus is provided for use in pointing wire wherein a point, or section of reduced cross-sectional area, is formed on a wire by pulling it through a pair of split wire forming dies to reduce the cross-sectional area of an elongated portion of the wire spaced from the ends thereof. A point is formed by cutting the wire through the elongated portion to expose a free end thereof.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a device embodying the present invention for use in pointing wire in accordance with the method of the present invention.

FIG. 2 is a somewhat enlarged plan view of the device of FIG. 1 shown in working engagement with a wire positioned therein.

FIG. 3 is a somewhat further enlarged sectional view taken along the line 33 of FIG. 2.

FIG. 4 is a fragmentary sectional view taken along the line 44 of FIG. 3.

FIG. 5 is a fragmentary side elevational view of a wire which has been formed by the device of FIGS. 1-4.

FIG. 6 is a fragmentary side elevational view of the wire of FIG. 5 after it has been pointed in accordance with the present invention.

FIG. 7 is similar to FIG. 2 but of somewhat reduced size and shows the dies in an open position, the closed position of the dies being shown by broken lines.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT AND METHOD In accordance with the present invention, a wire or rod is pointed by positioning an axially extending portion thereof spaced from its ends betweena pair of split wire forming dies. The dies are brought into forming engagement with the wire to reduce the cross-sectional area of an elongated portion thereof. After forming, the wire is removed from the dies and cut transversely of its elongated portion to expose at least one free end of the elongated portion.

Turning now to the drawing, a device embodying the present invention and illustrating the method thereof is indicated generally by the reference numeral 10 and comprises a die case or die holder 12 which has an upwardly opening generally wedge-shaped recess 14 formed therein. A die set which comprises a pair of split wedged-shaped forming dies generally indicated at 16, 16 is received within the recess 14. The forming

dies

16, 16 are constructed and arranged to move transversely toward and away from each other in response to respective forward and rearward movement longitudinally of the die holder 12. The

dies

16, 16 move toward each other to a closed position in forming engagement with an associated portion of a wire W, po sitioned therebetween with its axis 18 in general alignment with the longitudinal axis of the device 10, when axial pulling force is applied to the wire W in a forward direction, as indicated by the arrow 19 in FIGS. 1 and 2. Application of reverse or pushing force to the wire in an axial direction causes the forming dies 16, 16, to move out of working engagement with the wire or toward an open position to effect release of the wire W as-will be hereinafter further discussed. In FIGS. 1 and 2, the

dies

16, 16 are shown in closed or working position. The open position of the dies is shown in FIG. 7.

Considering the device in further detail, the die holder 12 may take various forms, but preferably, and as shown it is machined from a generally rectangular metal block. The die recess 14 is defined by a generally horizontally disposed bottom wall 20, a pair of generally vertically disposed and inwardly facing

side walls

22, 22, a front wall 24 and a rear wall 26. The

side walls

22, 22 converge toward the forward end of the holder 12. Preferably, each side wall 22 forms an angle of at least 7 with the axis 18. Upwardly opening

slots

28, 28 formed in opposite ends of the die holder 12 communicatewith the recess 14 to facilitate positioning of the wire W therein. A pair of

pins

30, 30 spaced inwardly from the

side walls

22, 22 project upwardly from the bottom wall 20 for a purpose to be hereinafter discussed.

The

dies

16, 16 are substantially identical and each has a lower surface 32 for sliding engagement with the bottom surface 20 and a generally vertically disposed and outwardly facing bearing surface 34 for complementary sliding engagement with an associated side wall 22. Each die 16 also includes a generally vertically disposed and inwardly facing abutment surface 36 for mating engagement in an axial plane with a corresponding abutment surface on the other of the dies when the dies are in closed position. Each die 16 has a groove 37 which opens downwardly through the lower surface 32 thereof. The groove 37 is spaced inwardly from and generally parallel to an associated bearing surface 34. The

pins

30, 30 cooperate with the

grooves

37, 37 to retain the

bearing surfaces

34, 34 in engagement with the

side walls

22, 22.

Each die carries a die insert 38 which is received in a vertically extending notch, substantially as shown. The insert is retained in the notch by a pair of threaded

fasteners

40, 40. The inserts are made from material harder than the material from which the

dies

16, 16 are made and may, for example, be made from tungsten carbide or like material. Each insert 38 defines one half of a longitudinally extending die cavity 42, best shown in FIG. 4, which is generally coaxially aligned with the axis 18 when the

dies

16, 16 are in closed position and which will be hereinafter further described. Generally semi-cylindrical inwardly opening

recesses

44, 44 formed in each die 16 open through opposite ends thereof and communicate with the die cavity 42, as

shown in FIG. 4.

The

dies

16, 16 are arranged for movement in unison within the recess 14 by a pair of

dowel pins

48, 48 which are carried by one forming die and which project therefrom and into pin receiving openings formed in the other forming die 16. The forming

dies

16, 16 are retained in the recess 14 by a pair of

retaining plates

50, 50 secured to the upper surface of the die holder 12. Each plate 50 has an elongated marginal portion or lip which extends inwardly beyond an associated side wall 22.

Considering now the preferred configuration of the die cavity 42 and referring particularly to FIG. 4, wherein one half section of the die cavity defined by one of the dies is illustrated. The cavity includes a generally cylindrical portion 52 which opens through the rear end thereof and communicates at its inner end with a bell mouth portion 54. The bell mouth portion blends smoothly into a generally conical portion 56 which forms an approach angle of approximately 14, the latter angle being designated by the numeral 58. The inner end of the conical portion 56 communicates with a generally cylindrical bearing portion 60 which has a cross-sectional area throughout the axial length thereof smaller than the cross-sectional area of the wire W. Each insert 38 has a relieved or cut away area immediately adjacent one side of the die cavity section formed therein, the relief areas of the

dies

16, 16 being designated by the

numerals

64, 64 in FIG. 3. Each relief area 64 cooperates with the die cavity section in an associated die 16 to define a relatively sharp shearing edge 66 which defines one side edge of the cavity section. Thus, as best shown in FIG. 3, each insert 38 has one shearing edge 66 which cooperates in shearing relation with an associated abutment surface 36 on the other of the dies when the

dies

16, 16 move to closed position.

A wire W to be pointed is positioned between the

open dies

16, 16 with its axis generally aligned with the longitudinal axis of the device so that an elongated portion of the wire spaced from the ends thereof is positioned is generally coaxial alignment with the two half sections of the die cavity 42. Slight forward movement of the

dies

16, 16 within the recess 14 causes the dies to move into frictional engagement and toward working relation with opposite sides of the wire W. Thereafter, pulling force is applied to the free end of the wire in the direction of the arrow 19 by jaws 68, 68 or some other suitable means, which may, for example, comprise a chain and dog mechanism on an associated wire drawing machine (not shown). The initially applied force causes the

dies

16, 16 to move forwardly in the holder 12 and into tight gripping engagement with the wire W. As additional force is applied to the wire W in the direction of the arrow 19, the

dies

16, 16 continue to move forwardly with the wire and radially inwardly in working engagement with the wire and toward mating engagement with each other. As the dies approach their closed or mating position, the portion of the wire received within the cavity 42, formed therebetween, will be reduced in cross-sectional area. Some slight flash may be produced on the wire as the dies approach their fully closed or mating position, however, this flash will be trimmed from the wire by the shearing action of the edges 66 when the dies move to fully closed position. Force is continually applied to the wire inthe direction of the arrow to draw an elongated portion of the wire through the bearing portion 60 of the die cavity so that an elongated portion of substantially uniform diameter and reduced cross section is formed on the wire W, as indicated at 70 in FIG. 5. Thereafter, the dies l6, 16 are opened by reversing the direction of force on the wire W. Since a portion of the wire forward of --the die cavity 42 has a cross-sectional area greater than the cross-sectional area of the die cavity at its forward end, continued application of force to the wire W in a reverse direction causes the dies 16, 16 to move rearwardly within the recess 14. The

pins

30, 30 cooperate with the

grooves

37, 37 to cause the dies to separate or move transversely outwardly and away from each other as they move toward the rear of the recess l4. Ultimately, a release position is attained wherein the wire W may be lifted vertically out of the device. Suitable means (not shown) will, of course, be provided for removing any flash or trimmed material from the die recess 14 when the dies attain an open position. The pointing operation is completed by cutting the wire W through the elongated portion thereof as indicated at 72 in FIG. 5, to expose a free end 74 of the elongated portion, as shown in FIG. 6.

I claim:

1. Apparatus for reducing the cross-sectional area of a portion of an axially elongated wire and comprising a die set including a pair of opposing mating dies, each of said dies having a radially inwardly opening recess therein extending axially therethrough and defining a portion of a die cavity, each recess cooperating with the other when the dies are in mating relation to define said die cavity, said die cavity including an axially elongated portion having a cross-sectional area throughout the length thereof smaller than the cross-section of the wire, means restraining said die sections for radial movement toward and away from each other respectively into and out of mating relation and for axial directional movement in unison, means supporting said die sections for radial and axial movement, and means for moving said dies radially inwardly toward each other into mating relation and working engagement with associated opposite side portions of a wire positioned therebetween with the axis thereof coaxially aligned with the axis of said die cavity in response to movement of said dies in one axial direction relative to said supporting means.

2. Apparatus as set forth in claim 1 including means for moving said dies away from each other and out of working engagement with a wire positioned therebetween in response to movement of said dies in a direction opposite said one axial direction and relative to said supporting means.

3. Apparatus as set forth in claim 1 wherein said supporting means comprises said means for moving said dies toward each other.

4. Apparatus as set forth in claim 1 wherein said supporting means comprises a die holder having a generally wedge-shaped upwardly opening die receiving recess partially defined by a pair of vertically disposed and inwardly facing side walls converging in said one axial direction, said dies received in said recess, each of said dies having a generally vertically disposed outwardly facing bearing surface for complementary sliding engagement with an associated one of said side walls, said side walls and said associated bearing surfaces comprising said means for moving said dies toward each other.

5. Apparatus as set forth in claim 4 including means for moving said dies away from each other in response to movement of said dies in a direction opposite said one axial direction and relative to said supporting means.

6. Apparatus as set forth in claim 5 wherein said recess includes a bottom surface, said die holder has a pair of pins projecting upwardly from said bottom surface, each of said dies has a lower surface in sliding engagement with said bottom surface and a groove opening downwardly through said lower surface and receiving an associated one of said pins therein, said groove being parallel to an associated one of said side walls, each of said pins cooperating with an associated one of the grooves to maintain one of said dies with the bearing surface thereof in sliding engagement with an associated side surface.

7. Apparatus as set forth in claim 4 including means for retaining said dies in said recess.

8. Apparatus as set forth in claim 1 wherein said restraining means comprises a dowel pin carried by one of said dies and slidably received in the other of said dies.

9. Apparatus as set forth in claim 1 wherein each of said dies includes an insert, said insert defining said axially elongated portion.

10. Apparatus as set forth in claim 1 wherein each of said dies has a radially inwardly facing abutment surface thereon engageable with said abutment surface on the other of said dies when said dies are in mating relation, said die cavity defining portion of each of said dies opens through an associated one of said abutment sur faces, and each of said dies has a relief area therein generally adjacent one side of said die cavity defining portion and opening through said abutment surface thereof, said relief area cooperating with said die cavity defining portion to form a shearing edge which defines one edge of said die cavity defining portion, each said shearing edge cooperating in shearing engagement with said abutment surface on the other of said dies when said dies are in mating relation.

11. A method for pointing a wire having a substantially uniform cross-sectional area throughout its length comprising the steps of positioningan axially elongated portion of the wire spaced from the ends thereof between a set of wire forming dies, moving said dies into forming engagement with said elongated portion to re duce the cross-sectional area of said elongated portion throughout its length, removing said wire from said dies, and cutting said wire at said elongated portion after the cross-sectional area thereof has been reduced to form at least one free end on said elongated portion.

Claims

10. Apparatus as set forth in claim 1 wherein each of said dies has a radially inwardly facing abutment surface thereon engageable with said abutment surface on the other of said dies when said dies are in mating relation, said die cavity defining portion of each of said dies opens through an associated one of said abutment surfaces, and each of said dies has a relief area therein generally adjacent one side of said die cavity defining portion and opening through said abutment surface thereof, said relief area cooperating with said die cavity defining portion to form a shearing edge which defines one edge of said die cavity defining portion, each said shearing edge cooperating in shearing engagement with said abutment surface on the other of said dies when said dies are in mating relation.

11. A method for pointing a wire having a substantially uniform cross-sectional area throughout its length comprising the steps of positioning an axially elongated portion of the wire spaced from the ends thereof between a set of wire forming dies, moving said dies into forming engagement with said elongated portion to reduce the cross-sectional area of said elongated portion throughout its length, removing said wire from said dies, and cutting said wire at said elongated portion after the cross-sectional area thereof has been reduced to form at least one free end on said elongated portion.