US2206842A - Abrading machine - Google Patents

Description

' H;S.INDGE 2,206,842

ABRADING MACHINE 4 2 Sheets-Sheet 1 Filed May 15, 1937 HERBERT S. I NDG'E y 2, 1940- H. s. IND GE 2,206,842

'ABRADING MACHINE- Filed May 13, 1957 2 Sheets-Sheet 2 HERBERT .S' INDG'E F1 9." 6

Patented July 2, 1940' PATENT, OFFICE ABRADING MACHINE Herbert S. Indge, Wcstboro; Mass., assignor to Norton Company, Worcester, Mass., a. corporation of Massachusetts Application May 13, 1937, Serial No. 142,343

5 Glaims.

The invention relates to abrading machines and, with regard to its more specific features, to a lapping machine. 1

One object of the invention is to provide an efficient lapping machine for lapping the races of ball bearings. Another object of the invention is to provide a machine of the type indicated of high productive-capacity. Another object of the invention is to provide a machine adapted to .im-

part a smooth polished surface to a workpiece and capable of dependable operation in practi cal use. Other objects will be,in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangements of parts, as will be exemplified in the structure to be hereinafter described, and

Figure 1 is a side elevation of a lapping ma-' chine constructed in accordance with the invention;

Figure 2 is a fragmentary rear elevation of the machine, showing the mechanism for oscillating the upper wheel head;

Figure 3 is an enlargedfragmentary cross sectional view on' the line 3-3 of Figure 1;

Figure 4 is a front elevation of the machine;

Figure 5 is a side elevation similar to Figure 1, showing a modification of the invention;

Figure 6 is a front elevation of the modification of Figure 5; A 1

Figure 7 'is a side elevation of a modified form of dressing device;

Figure 8 is a view, partly in plan and partly in horizontal section, of a modification whereby an internal race may be lapped.

Referring first to Figure 1, I provide a base 20 housing a driving motor 2|. As better shown in Figure 4, on the upper part of the base 20 are dovetailed ways 22. Referring now to Figure 1, mounted upon the ways 22 are a pair of slides 23 and 24 having formed therein ways complementary to the dovetailed ways 22. One of these slides 23 and 24 is adjustably secured in position upon the ways 22, as by means of a tightthrough which passes a screw shaft 21 suitably journale'd'in the base 2|! and having on the front thereof a hand wheel 23. Thus the slide 24 (or. ill-33) may be quickly adjusted machine. 1

On the upper side of the slide 23 is a fork 3B which is clearly shown in Figure 4. Journaled in the fork bymeans of a shaft 32 is a wheel 33. On the upper side of the slide 24 is a similar fork 3|. Journaled in the fork 3| by means of a shaft 34 is a wheel 35. The shape of each of these wheels, as shown in Figure 4, is that of a grooved pulley. V

The wheels 33 and 35ers rotated in the same angular direction and at the same peripheral velocity by the motor 2|. A work piece W fits fore and'aft of the in the grooves of the wheels 33 and 35 and is in a fixed position and rotated and the toric ball receiving surface is then lapped by a mechanism which will be described.

Considering now the means for rotating the wheels 33 and 35, and referring to Figures 1 and 4, mounted on the motor shaft 40 of the motor 2| is a pulley 4| which is connected by means of a belt 42 with a pulley 43 secured to the shaft 32 for the wheel 33. Also secured to the shaft 32 is a sprocket 33a. Secured to the shaft 34 is another sprocket 36. A third sprocket 31 ismounted on an arm 33 which is pivotally mounted at Men the slide 24. A spring 44 pulls the arm downward. A sprocket chain 4|a passes around all of the sprockets 33a, 36 and 31, the chain being kept tight under varying adjustments of the slide by means of idler sprocket 31. Thus are the wheels 33 and 35 driven at the same rate of speed and in the same angular direction. I

Referring now to Figure 1, extending rearwardly from the base 20 are parallel spaced walls 45, 45 between which is located a bell crank lever 45 mounted on a trunnion 41 journaled in the walls 45, 45. Between the walls 45, 45 and pivotally connected thereto by means of a shaft 48 is a cylinder 43'connected by pipes 50, 50 to a suitable valve, not shown, connected to a suitable source of fluid under pressure and exhaust. The usual four-way .hand valve and a source of air under pressure bay be used. In the cylinder 4% is a piston 5| whose piston rod 152 is connected at 53 to one end of the bell crank lever 46.

A link 55 is connected at 56 to the bell crank lever 46 andat 51 to a support 60 which is pivotally mounted on a shaft 3! extending between the walls 45, 45. The bell crank 46 and link 55 thus constitute a toggle to move the support 64.

. When the piston 5| is up, the bell crank 45 is in thejdottedl line position shown in Figure 1 and thei'togglei'isbroken.- This draws downwardly the rear portion of the support 60 and swings upwardly a lapping wheel 65 which is supported by the support 60 in position to contact the work piece W which is held and rotated by the . wheels 33 and 35. When the piston 5| is moved downwardly in the cylinder 49, the bell crank lever 46 ismoved to the full line position of Figure 1, thus lowering the wheel 65.

Referring now to Figures 1 and 4, the wheel 65 is mounted upon a shaft 86 extending between and journaled in the side plates for a forked support 01 constituting an integral part of a vertical slide 68 which is mounted upon dovetailed ways 69 of a column I0 attached to the front of a shaft II journaled in thesupport 60. Attached to the slide 68 is a nut I2 through which passes a screw shaft 13 journaled at I4 in-the column 10. A hand wheel 'ISattached to the screw shaft or aluminum oxide bonded with any suitable" bond such as vitrified ceramic, or resinoid, or

naturalresin, or rubber or any other known type. f

The wheel 65 is adjustedup and down on the column I0 in order that it may be placed, 'in such a position that the axis extended of the shaft II shall be tangent to the toric center circle of the wheel 65. The shaft II is oscillated about its axis andthus the wheel 65 will lap a torlc. surface upon the work piece W.

Considering now the mechanism for oscillating the shaft II and thus oscillating the toric surface of 'the'wheel- 65about a line tangent to its toric circle, I provide, as shown in Figure l, a motor mounted upon'a stand 0| fixed to the Support 60. Mounted on the armature shaft 82 of the motor 80 is a fiy wheel plate 83 having fastened thereto an arm 84. As better shown in Figure 2, the'arm 84 has a stud 85 on one end thereof which passes through an arcuate slot 86 in an arm Ill fastened to the shaft II. When the motor 810 is energizedythe arm 81 is oscillated and this oscillates the shaft 'II.

I provide means for truing the wheel 65 from time to time, giving it a true toric surface. As shown in Figure 1, I provide a bracket 90 removably to the sides of the fork 61 whichsupports through wear, a new bracket 90 isprovided: I

: may provide a series of brackets 90 of slightly different size for thejdressing of the wheel 65 indifferent sizes thereof.

Referring to; Figure 4, in order to' rotate the wheel 65 for dressing purposes, a long belt, not shown, may beused to connect -the pulley H with a'pulley 99 fastened" to the wheel shaft 66 of the wheel 65.

.A. modificationoff'thei invention is shown in Figures fi and' fiiwherein an intermediate slide I00 is provided mounted upon the ways 22, which slide I00 journals awheel IOI similar to the wheels, 33 and 35.; (This wheel IOI supports the I To dress the wheel after 'it has been worn, that is, reduced in diameter downward pressure of the wheel 65. This constructionis preferably used in the case of small work piecesor in any case where the lines of tangency between the work piece W and the wheels 33 and 35 are such that "there would be danger of deforming the work piece W from its circular condition due to wedging action of the wheels 33 and 35. The drive for the several wheels is illustrated in Figures 5 and 6 and as therein shown, a motor I05 has a pulley I06 driving a pulley I01 mounted on a shaft I08 journaled in the machine frame. A large pulley I09 secured to the shaft I08 has three V grooves, around one of which passes a belt H0 driving a pulley III fastened to the shaft-H2 which supports the wheel I 0|. A continuous belt II3 passes around pulleys H5 and H5 secured to the shafts 32 and 34 that support the wheels 33 and 35. The belt I I3 also passes twice over the pulley I09 and around idler pulleys I20 and'I2I journaled in brackets I22 and I23 adjustably bolted to the machine frame, as shown in Figure 5.

The wheels 33 and 35 and IN in all modifications of the invention may be made of steel or they may be made of abrasive material of any type, if desired. The action is'a lapping action in which the work piece is rotated at a moderate speed in contact with the abrasive wheel 65 which has a toric surface and which is being oscillated about a line tangent to the toric center, as stated.

thereto a helical gear I25 meshing with another helical gear I26 which is fixed to a shaft i2! journaled in a bracket I28 fastened to the forked support 61. As shown in Figures 1 and 4, on the rear end of the shaft I21 is mounted a fan I30, for example having blades of the type used as governors for spring actuated machinery, such as music boxes and the like. This fan I30 acts as a regulator to prevent the wheel 65 from attaining the speed of the work piece. Any other type of regulator, such as that used in phonographs, may be substituted, or a plain friction brake might be employed.

By means of the actuating cylinder 49, the wheel 65 can be quickly, raised so that a work piece may be introduced into the machine. The wheel may be as quickly lowered into position and the lapping operation is not only effective but quickly performed by the dragging action of the oscillating wheel 65. Relative motion between the workpiece and the wheel 65 is not uniform but irregular and produces a true lapping action. Figure 3 illustrates in dotted lines the oscillating action of the wheel 65 relative to the work piece W.

Referring now to Figure '7, I have illustrated a modification of the dressing device which may be readily adjusted for wheel wear. As shown therein, a dressing arm 93a supports a threaded diamond holder 95a having a diamond 96 which" a ing betweenand fastened to the parallel guides I36. A hand wheel Ill integral with or attached to the nut I39 facilitates the turning of the nut I39 to adjust the center of oscillation of the diamond 96 radially of the wheel 65.

Referring now to Figure 8, I have therein illustrated an attachment which may be provided for the lapping ofthe internal surfaces of the external races of ball bearings. This attachment comprises a bracket I50 having a dovetailed portion I5I fitting the slideways 69. This bracket I50 may be clamped in place on the slideway 59 by means of a tightening screw I52 passing through a slotted dovetailed portion I53 of the bracket I50. Bracket I5!) is a double angle in plan view and on the frontthereof are slideways I55 supporting a slide I 56 having forked extensions I51, I51 journallinga shaft I58 upon which is mounted a toric lapping wheel I59 which is small enough to fit inside of a work piece W to lap an internal raceway thereof. The shaft I58 is also preferably restrained from spinning in any suitable manner, asfor example by the mechanism shown in Figure 4 and previously described. Similarly, the slide I56 may be adjusted vertically in the same manner in which the slide 61 is adjusted vertically.

A metallic toric wheel or lap, charged with suitable abrasive, may be substituted for the bonded abrasive lap or toric wheel.

It will thus be seen that there has been pro vided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are. successfully achieved. As many possible embodiments may be made of the above inventionand as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth onshown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

mounted on an axis parallel to the axes of saidpair of wheels, means to retard the rotation of said toric wheel, and means to oscillate said toric wheel about an axis which is tangent to the toric circle.

2. In apparatus as claimed in claim 1, the combination with the parts and features therein specified, of meansf or adjusting the toric wheel in a direction transverse to its axis of oscillation.

'3. In apparatus of the class described, a pair of wheels mounted on parallel axes, means to rotate one'of said wheels, a toric lapping wheel mounted opposite said pair, means to oscillate said toric lapping wheel about an axis tangent to the work circle, and means to restrain the rotation of the toric lapping wheel, whereby a work piece held by the pair of wheels will be rotated in contact with the toric lapping wheel and lapped thereby.

4. In apparatus of the class described, a machine base, a slide, a wheel mounted on said slide, a second slide, a wheel mounted on second slide parallel to said first slide, the movement of the slides being transverse to the axis of the wheels, an abrasive wheel, means to oscillatethe abrasive wheel on an axis perpendicular to its geometrical axis, and toggle means to raise and lower the abrasive wheel.

5. In appraratus of the class described, a base, a pair of work supporting and rotating wheels mounted on said base, means to adjust the wheels toward and from each other, means to 'rotate one of the wheels, a rock shaft, means to abrasive wheel mounted in the fork whereby ad'- justment of the slide adjusts the periphery of the wheel toward and from the axis of oscillation, a support for the rock shaft, a pivotal mounting for the .support, and a toggle mechanism to move the rock shaft as a unit and not about its axis to bring the abrasive wheel into and out of engagement with the work piece held by the said pair .of wheels mounted on the base.

HERBERT S. INDGE.

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