US2948996A - Apparatus for string polishing work pieces - Google Patents

Description

Aug. 16, 1960 R. F. RULE APPARATUS FOR STRING POLISHING WORK PIECES Filed Feb. 24, 1959 5 Sheets-Sheet 1 FIG.

INVENTOR. RICHARD F. RULE ATTORNEY Aug. 16, 1960 R. F. RULE 2,948,996

APPARATUS FOR STRING POLISHING wosx PIECES Filed Feb. 24, 1959 s Sheets-Sheet 2 FIG. 5

V N s RICHARD FI.NFUTRE ATTORNEY Aug. 16, 1960 R. F. RULE APPARATUS FOR STRING POLISHING WORK PIECES 5 Sheets-Sheet 3 Filed Feb. 24, 1959 INVEIIVTOR. RICHARD F. RULE ATTORNEY Aug. 16, 1960 R. F. RULE 2,948,996

APPARATUS FOR STRING POLISHING WORK PIECES Filed Feb. 24, 1959 5 Sheets-Sheet 4 w, I F/a.a

FIG /0 F-, RICHARD R NVQSTERE BY f W A T TOR/V5 Y Aug. 16, 1960 R. F. RULE 2,948,995

APPARATUS FOR STRING POLISHING WORK PIECES 5 Sheets-Sheet 5 Filed Feb. 24, 1959 INVENTOR. RICHARD F. RULE ATTORNEY eiay-d. V

States APPARATUS FOR STRING POLISHING WORK PIECES Filed Feb. 24, 1959, Ser. No. 795,007

6 Claims. (Cl. 51-145) 1 EMj-y invention con ists in a new and useful improvement in apparatus for string polishing work pieces, and is designed more particularly or polishing the ball groove of the inner ring of a ball bearing or a similar object, when abrasive-impregnated string rs used. It provides grim automatic operation which will be cut oil in the event of failure to feed the work pieces, or loss of tension of the string. My apparatus is unique in that all ofi-ts operative elements are actuated by rotation of a single drive disc, thus synchronizing operation of all P rt }While I have illustrated in the drawings and hereinafter fully describe one specific embodiment of my invention, it is to be distinctly understood that I do not consider t y-invention to be limited to said embodiment, but refer for its scope to the claims appended hereto.

{ In the drawings:

lis a fragmentary perspective of the upper portion of myfapparatus.

Fig. 2 is an enlarged horizontal section on the line 2-4 of Fig. 1, in the direction of the arrows.

Fig. 3 is a detail of the cam and roller for oscillation of the mandrel. 1

Fig. 4 is an elevation of one end of the apparatus, the casing being shown in section.

Fig. 5 is a vertical section on the line 5-5 of Fig. 4, in the direction of the arrows.

' Fig. 6 is an elevation of the other end of the apparatus, the parts being in diiferent positions, the casing being shown in section, and the feed mechanism being omitted.

Fig. 7 is a vertical section on the line 7-7 of Fig. 6, inthe direction of the arrows.

j Fig-8 is an enlarged detail of the mandrel in position for the feed mechanism to mount a work piece on the mandrel.

f Fig. 9 is an enlarged detail showing the feed mechanism retracted and the mandrel and work piece positioned for spinning the work piece to be polished.

@Fig. 10 is an enlarged detail showing the mandrel disposed to strip the polished work piece therefrom. -Fig..ll is a greatly enlarged detail showing the forwarding .rollers for the string, and means for oscillating thestring.

Fig. 12 is a top plan of the work piece hopper.

Fig. 13is a vertical section on the line 13-13 of Fig.

12, in the direction of the arrows.

Fig. 14 is a perspective of the work piece hopper, part broken away, and the feed chute. i As shown in the drawings, my improved apparatus has afcasing C having a front wall 1, a rear wall 2, end walls? and 4, a bottom 5 and a top 6. A horizontally disposed shaft S is suitably journaled in the walls :1 and 2 (Figs. 4, 5, '6 and 7) with a pulley S-1 thereon for rotating the shaif t S by a belt from a suitable prime mover, such as an electric motor (not shown). A drive disc D is fixed on the shaft S in the casing C. The disc D has a peripheral bevel D 1.

A horizontally disposed post 7 is mounted on the wall 21(Figs. 1 and 2) on which a sleeve 8 is slidably mounted. The-sleeve 8 has a median, transverse wall 8-a.

atent 2,948,995. Patented Aug. 16, 1960 w 2 An expansion spring 9 in the sleeve 8 bears against the post 7 and a ball bearing 8-b mounted in the sleeve 8 against one side of the wall 8-a. A mandrel M has its inner end M-1 received in the sleeve 8 against a ball bearing 8-c mounted against the other side of the wall 8-a. The mandrel M is journaled in a ball bearing M-2 which is journaled by pins P in slots P-1 in a hanger M-3 pivotally mounted on the under side of the top. 6 of the casing C (Figs. 1, 2 and 3). The hanger M-3 has a depending finger M-4 carrying a roller M-S. The drive disc D has an arcuate cam D-2 on its rear face (Figs. 2 and 3) with portions D-3 and D-4 to coac-t with the roller M-5 to oscillate the mandrel M. The mandrel M has its forward end M-6 journaled in a bore 1-a in the wall 1, and a conical stripper abutment 1-b is formed at the outer end of the bore 1-a. The mandrel M has a conical cam M-7 co-acting with the bevel D-1 of the drive disc D, as a cone clutch whereby the mandrel M is rotated when it is projected forwardly by the spring 9 into contact with the rotating drive disc D (Fig. 9).

I will now describe the mechanism for feeding the work pieces W to the mandrel M. A hopper H (Fig. 4) above the top 6 of the casing C is mounted on one end by a ball and-socket joint H'1 on the upper end of a pitman H-2 journaled on a crank H-3 on the end 5-2 of the shaft S passing through the rear wall 2 of the casing C. A feed chute F is hinged on the other end of the hopper H, extends downwardly outside of the wall 1 of the casing C (Fig. 4), and has, at its lower end, a lateral arm F-l slidable in a socket F-2 in the wall 1 (Figs. 4, 8, 9 and 10). The arm F-1 has mounted on its end a pin F-3 whichpasses through the socket F-2, and a bore F-4 in wall 1 at the inner end of the socket F-Z, and carries on its end a roller F-S. A contraction spring F-6 coiled about the pin F-3 and attached to the arm F at one end and to the wall 1 at its other end, biases the roller F-5 against the front face of the drive disc D. The drive disc D (-Fig. 2) has on its front face a cam groove D-5 with portions D-6 and D-7 co-act-ing with spring F-6 to cause oscillations of the feed chute F.

The feed chute F has a discharge throat F-7 co-axial with the mandrel M. It will be noted (Fig. 8) that the 'feed chute F and its discharge throat F-7 are so dimensioned and related that the work pieces move from the hopper H, edgewise through the chute F and sidew-ise through the throat F-7 so that their bores W-1 are so disposed that the pieces W can be mounted on the conical end M-6 of the mandrel M in a tight fit (Fig. 9).

-I will now describe the mechanism for placing the abrasive-impregnated string A on the work pieces W. A strut 10 is mounted on the end walls 3 and 4 slightly above the bottom 5, in the casing C. A pair of roners 11 and 12 are journaled on the strut 10 above an 01'lfi\. 13 in the bottom 5 of the casing C. A second pair of rollers 14 and 15 are journaled on the strut 10 above an orifice 16 in the bottom 5. Arcuate segmental racks 17 are mounted on the rear face of the drive disc D and co-act with pinions 11a and 14-a on the rollers '11 and 14, the rollers 12 and 15 being pressure idlers. A strut 18 is mounted on the end walls 3 and 4 of the casing C slightly above the strut 10. A pair of hollow shafts 19 and 20 are journaled in the strut 18 and the wall 1, carrying radial hollow tubes 21 and 22, respectively, disposed outside of the casing C. These tubes 21 and 22 have openings 21-a and 22-11, respectively on the sides at their outer ends. Segmental rack sections 23 and 24 are removably mounted on the periphery of the drive disc D and co-act with pinions 19-a and 29-a on the shafts 19 and 20, respectively, to intermittently rotate shafts 19 and 20. It is obvious that, as above mentioned, the number of revolutions of the tubes 21 and 22 by ro.

tation of the shafts 19 and 20 can be determined by the number of sections 23 and 24.

A frame R (Figs. 1 and 2) is vertically slidable in slots 1-c in the front wall 1, and carries a pair of freely rotating, grooved rollers R-l outside of casing C, disposed on either side of the mandrel M. The frame R (Fig. 1) is so disposed relative the drive disc D as to be raised by the passage along the bottom of the frame R of a pin R-2 received in one of the holes R-3 in the rear face of the drive disc D. The frame R drops by gravity after passage of the pin R-2.

The string A passes from a spool A-l (Fig. 11), through the orifice 13 into the casing C, to and between the rollers 11 and 12, to and through the hollow shaft 19, through the tube 21 and out of same through the opening 21-a outside of the casing C, to and over the rollers R4, to and through the opening 22-a, through the tube 22 and through the shaft 20, into the casing C, to and between the rollers 14 and 15, and through the orifice 16 out of the casing C to waste.

In Figs. 2, 8, 9 and 10 there is shown an automatic cut-off switch mounted on the front of the feed chute F. Should the chute F fail to feed a work piece W to the mandrel, a spring-pressed plate 0-1, being contacted by the mandrel M, will be pressed into contact position to close a circuit through the wires 0-2 to energize a suitable cut-off means (not shown) to de-energize the driving motor, thereby stopping the apparatus.

A suitable automatic cut-off switch may be provided to be operated by a suitable tension pulley bearing on the string A, which would stop the apparatus on loss of tension on the string A.

Having described the structural details of my apparatus, I will now describe its operation.

The hopper H being charged with the work pieces W to be polished (Figs. 12 and 13), and the string A being disposed as shown in Figs. 1, 4 to 7 and 11. The drive disc D is rotated, in the direction of the arrow in Fig. 7, causing passage of the portion D-7 of the groove D-S on the front face of the disc D past the roller F-S of the feed chute P, which allows the chute F to be projected by its spring F-6 toward the conical end M-6 of the mandrel M (Fig. 8) thereby mounting the work piece W which has been precipitated by rocking of the hopper ii to the lower end of the chute F and aligned with the discharge throat F-7 of the chute F which is co-ax-ial with the mandrel M. As this action occurs, the portion D-3 of the cam D-2 on the rear face of the disc D causes the roller M-S of the mandrel M to retract the mandrel M to be at rest. When the cam D-Z has passed the roller M-S, the spring 9 (Fig. 2) projects the mandrel M to cause its conical cam M-7 to engage the bevel D1 of the disc D (Fig. 9) to rotate the mandrel M to spin the work piece W mounted thereon. It will be noted (Figs. 4 and 6) that the work piece W is so mounted on the mandrel M that its ball groove W2 (Fig. 9) aligned with the string A carried by the roller R-l.

The racks 23 and 24 (Figs. 5, 7 and 11) on the periphery of the disc D cause revolution of the tubes 21 and 22, thereby causing the string A to oscillate in the ball groove W-Z of the spinning work piece W. The racks 17 (Fig. 11) cause the string A to be fed into and out of the apparatus, thereby supplying fresh string A for the polishing operation.

The racks 23 and 24 are so disposed on the disc D as to revolve the tubes 21 and 22 only when the mandrel is spinning the work piece W thereon.

The frame R is actuated to cause the rollers R-l to lift the string A from the work piece W on the mandrel M, when the mandrel is at rest, the polishing operation having been completed, and lower the string A after a new work piece W has been mounted on the mandrel M.

When the rotation of the disc D causes the portion D-4 of the cam D-2 on the rear face of the disc ID to A1 engage the roller M-5 (Fig. 3), the mandrel M is so retracted (Fig. 10) as to cause the polished work piece W to be stripped from the mandrel M by the abutment l-a. The polished work piece W is then discharged from the apparatus by any suitable means (not shown).

Having described my invention, what I claim is:

1. In an apparatus for string polishing work pieces, the combination of a casing; the. drive disc journaled in said casing; a mandrel rotatably mounted in said casing, and having one end projected from said casing; a hopper for the work pieces, mounted above said casing and having a feed chute with a discharge throat; means actuated by said disc, adapted to move said chute relative said mandrel to mount a work piece in said throat on said end of said mandrel; means, actuated by said disc, adapted to intermittently rotate said mandrel to spinthe work piece mounted thereon; a pair of forwarding rollers mounted in said casing, intermittently rotated by said disc, and adapted to draw the string into the apparatus; a second pair of forwarding rollers mounted in said. casing, intermittently rotated by said disc, and adapted to draw the string out of the apparatus, the string being led from said first pair of rollers, over the work piece on the mandrel, to said second pair of rollers, and being held under tension against the work piece to polish it when the mandrel spins the work piece; and means intermittently actuated by said disc, adapted to oscillate the portion of the string in the apparatus relative the spinning work piece. v

2. An apparatus, according to claim 1, in which said means for moving said chute comprises an arm on said chute, slidable relative said casing, and biased. toward said casing, a roller on said arm, and a cam groove in said disc co-acting with said roller to cause oscillation of said chute.

3. An apparatus, according to claim 1, in which said means for intermittently rotating said mandrel comprises a peripheral bevel on said disc, a conical cam on said mandrel, a journal for said mandrel pivotally mounted in said casing and having a roller, a spring biasing said mandrel to cause said conical cam to engage said bevel, and an 'arcuate cam on said disc adapted to engage said roller to retract said mandrel to disengage said conical cam from said bevel.

4. An apparatus, according to claim 1, in which two arcuate racks are mounted on said disc, one of the rollers of each of said pairs of rollers for forwarding the string has a pinion, and said racks engage said pinions, respectively.

5. An apparatus, according to claim 1, in which said means for oscillating the string comprises two hollow shafts journaled in said casing, each having an end projecting from said casing, two tubes mounted radially on said projecting ends, respectively, a pinion mounted on each of said shafts in said casing, and two peripheral racks on said disc, adapted to rotate said pinions on said shafts, the string being led from said first pair of forwarding rollers, through one of said shafts and its tube, and through the other tube and its shaft to said second pair of forwarding rollers.

6. An apparatus, according to claim 1, having a frame vertically slidably mounted in said casing, an adjustable pin on said disc and adapted to lift said frame, and a pair of rollers journaled on said frame, and disposed outside of said casing, said rollers having circumferential grooves disposed above the spinning work piece, and adapted to lift the string from the work piece when the mandrel is at rest.

References Qited in the file of this patent UNITED STATES PATENTS 1,873,129 Johnson Aug. 23, 1932 1,881,162 Aurori et a1. Oct; 4, 1932 2,121,025 Egger June 21, 1938 2,620,602 Schenk Dec. 9, 1952

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