US1605154A - Gear grinder - Google Patents

Description

Nov. 2 1926. 1,605,154

A. L. WILDER GEAR `GRINDER Filed April 1 8, 1924 3 Sheets-Sheet l A TTORNEY Nov. 2 1926.

A. L. wlLDER GEAR GRI NDER Filed April 1 8 5 Sheets-Sheet ATTo/JEY f 4L a 4L all 4 7 A. 5 5 5 n 5 n0 s 0 Y: l, t am Q m. m 5 e 9 .1. V 0 m 9 5 V mw /m 7 w o 0 85 1 S- m s l w m r S. 1 l am B 3 Il. -..du 6 u. 7 u. 4 u w E R M. 5 E 1. D m 8 f u. ,m 1 6 e www L A A /5 nm d 6 Pr n n- A .m 6 F n 5 n W. 2 7 m 6 .fk M nl 5 6 5 .w.... T M b1 2 Z 5 9 0 u. 1 .fm 6 7 v om Hu 9W 54A 4^ 5 HH v 1 0 N Patented Nov. 2, 1926.

UNITED STATES 1,605,154 PATENT OFFICE.

ARTHUR L. WILDER, OF WETHERSFIELD, CONNECTICUT, ASSIGNOR TO PRATT & WHIT- NEY COMPANY, OF NEW YORK,` N. Y., A CORPORATION OF NEW JERSEY.

GEAR GRINDER.

Application filed April 18, 1924. Serial No. 707,514. I

- high rate of production and operating upon a generating principle.

An object of the present invention is to provide improved means for rolling a gear blank past one or more grinding wheelsl and to provide improved means for indexing the gear blank at the end o f each rolling movement.

Another object of the invention is to provide an indexingmechanism com rising a constantly rotating member in the orm of a worm, this belng adapted to mesh wlth a gear on the work spindle. l Another object ofv the invention 1s to provide means for controlling the movements of the-wheels to feed them in a'direction vparallel 4to the movement of the gear blank spindle while the blank is being continuously rolled and indexed.

A further object of the invention is to provide mechanism which eliminates the necessity for flexible b ands to obtain the rolling movements of the gear blank during operation. Y

Finally, it is an object to provide a mechanism permitting the operation of grinding spur gears to be carried out automatically after the blank is loaded in the machine.

Vith these and other objects in view, my invention consists in the features of construction and operation set forth in the fo1- lowing specification and illustrated in the accompanying drawings.

In the accompanying drawings annexed hereto and forming a part of this specification, I have shown my invention'embodied in a spur gear grindin machine, but it will be understood that tie invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification .being relied upon for that purpose. i

In the drawings t Figure 1 isa plan view of the complete gear grinding machine, parts being broken away to more clearly indicate the means for operating the Work supporting slide.

Fig. 2 is a front elevation of the machine, parts being shown insection to more clearly mdicate their construction, the position of the wheels being diagrammatically indicated by dotted outlines. l

Fig. 3 is a transverse vertical sectional view taken substantially on line 3 3 of Fig. 1.

Fig. 4 is a detail of the improved indexing mechanism shown on a larger scale.

Figs. 5' andG are views of different portions of the constantly rotating member of the indexing mechanism.

In the above mentioned drawings, I have shown but one'embodiment of the invention which is now deemed preferable, but it is to beunderstood that changes and modifications may be made within the scope of the appended claimsvithout departing from the spirit of the invention.

Briefiy, and in its broadest aspect, my invention comprises the following principal parts: first, a. base; second, one or more wheel heads mounted adj ustably thereon and adapted to support independently adjustable grinding Wheels; third, a work supporting` slide adapted to be reciprocated by an adjustable crank, or other means, so that it may be moved through any predetermined distance determined by the particular gear being ground; fourth, a work spindle rotatably mounted on the slide and adapted to support a gear blank with its axis in alinement 'with the spindle; fifth, a fixed rack in the base adapted to mesh with a master gear on the work .spindle preferably correspond-` ing in pitch diameter and number of teeth to the' blank .being ground; sixth, another gear on the spindle preferably positioned just below the master gear and corresponding to the gear blank and adapted to be engaged by a rotating member of special form at each cycle of operations of the machine; seventh, means to feed the wheels in a direction parallel to the direction in which the blank is rolled during the grinding operation; and eighth, means controlling the rotation of the indexing member so that it will be rotated in timed relation to the reciprocatory movements of the work supporting slide.

Referring more in detail to the figures of `the drawings, I provide a base 10 having thereon Wheel supporting slides 11 preferably mounted upon a horizontal surface of the base and pre erably resting upon suitable ball bearings 12. Preferably, two of these slides 11 are provided, each having a wheel head 13 on which a rotatable abrasive wheel 14 is positioned. These slides 11 are similar to each other but oppositely disposed, so

that but one of these slides and its wheelsurface of this member 15 are suitable ways 18v engaged by corresponding ways of the lower surface of a member 19. The direction of movement of this slideor member 19 is preferablyexactly parallel to the work 'lgaging plane of the grinding wheel 14'. 20

n the upper surface of this member 19 are suitable ways 2()v disposed at right angles to i the ways 18 above mentioned. On these'is adapted to be adjusted the wheel head 13 carrying a spindle 22 which in turn carries the abrasive wheel 14. To rotate this wheel 14,'a motor 23 is carried on the head 13 whichis in driving connection with the wheel spindle 22 `by means of a belt 24 passing over the pulleys 25 and 2 6 shown in Fig. 1.

It will be seen from the above descri tion that a mounting is provided for the w eels 14 permitting them to be adjusted in'any direction, either longitudinally, transversely or angularly, relative to the blank, and their work `engaging surfaces therefore can be properly adjusted for any particular size or form of gear blank A being ground. Also by reason of the slides 11 being mounted on the bearings 12, the wheels 14 may be moved toward or from each other to feed them against the blank being ground. To adjust, the wheels 14 by means of the slides 15 and 19, hand wheels 28 and 29 are provided operating screws attached to each of these slides (not shown).

The work blank A is carried upon and actuated by movements of a large, vertically disposed slide 30 carried in suitable bearings 31 in the base 10 on either side of the machine. To aid in supporting the slide 30 an larch 29 is fixed to the base 10 having Ways engaged bythe upper portions of the slide 30. This slide 30 at one end is provided with bearing surfaces 32 adapted to be engaged by rollers 33 mounted upon a crank 34. The crank 34 ispreferably adjustably mounted, as indicated in Fig. 2, upon the uplper end of a vertically disposed shaft 35. T e shaft 35 andcrank 34 may be adapted to be rotated preferably by means of spiral gears 36 and 37, shown in Figs. 1 and 2.

On this slide 30 is disposed a work sup- I porting and rotating spindle 38, preferably mounted as indicated in Fig. 3, upon a vertical axis and suitably supported 1n suitable ball bearings 39 near its upper and lower ends so that it is easily rotated. This work spindle 38 carries a center 40 at one end in alinement with an oppositely disposed center 41 carried in a tail block 42 directly above the spindle 38 Aand movable withthe slide 30. Between these oppositely disposed centers 40 and 41 the work holding arbor 43 may be suitably positioned and rotated with rotation of the work s indle 38 through the driving dog 44 shown 1n Fig. 3. The work supporting arbor 43 is therefore adapted to be reciprocated while maintained in a vertical position by movements of the slide 30. Also the arbor 43 may rotate with the spindle 38 so that, by means of mechanism presently to be described, the blank A lirnay be given a rolling motion upon' any desired diameter.

Mounted near the lower end of the work spindle 38 is a gear 45 preferably corresponding in pitch diameterl and number of teeth to the gear A desired to be ground. This is adapted to mesh with a rack 46 fixed to a block 47 mounted within the base 10. This gear 45,v the rack 46 meshing with it and the parts associated therewith are made so that they may be readily removed and others substituted so that the machine may be adapted for different types and sizes of gears. Also, to eliminate any lostmotion between the teeth of the gear 4 5 and the rack 46, an auxiliary rack 461 is provided just below the fixed rack and resiliently urged in one direction by means of the spring 48 shown in Fig. 4. i This spring pressed rack 46a constantly urges the teeth of the master gear 45 in one direction against the teeth of the fixed rack 46 and is strong enough to prevent any retrograde movement of the gear 45 during the operative movements of the slide 30 and work spindle 38. YBy these means, there is no lost motion between the rack 46 and the gear 45 and errors from this source are therefore eliminated.

By means of the fixed rack 46 and the master gear 45 on the'spindle 3,8, reciprocatory movement of the slide 30 will simu]` taneously rotate the spindle 38, these two movements causing a rolling movement of the master gear 45 and the gear blank A upon their pitch cylinders along the pitch plane of the rack 46.

Also on the work spindle 38 and preferably directly below the master gear 45 re-l ferred to aboveis an indexing gear 50 having a. number of teeth preferably exactly equal to the number of teeth in the master gear 45 and the blank A being ground. This rotates and reciprocates with the combined movements of the work ,spindle 38- `so that its effective motion is a ro'lhng movement similar to that of the gear 45 and the blank A. This last mentioned gear 50 is adapted to be engaged by the member or worm 51 shown in Figs. 4, 5 and 6. This gear 50, however, does not mesh with the member or worm 51 exceptvwhen'l the sllde has been moved to approximately its `with the master rack 46 in a slightly different angular' or indexed position.

The position of the indexing members 51 relative to the rack 46 is clearly shown 'in Fig. 4. It will bevnoted that the member 51 is provided with a helical projection or thread, the width and proportions of which correspond to lthe teeth of theV rack 46. T he first convolution of the 'thread on the member 51 is so spaced from the end of the rack 46 that the master gear 45 will mesh correctly with it.'

The form of thev indexing worm 51 is clearly shown in- Figs. 5 and 6. It is preferably made in two half-portionssecured together in any desired manner (notshown). One of the half-portions 51u isprovided with, annular grooves similar to those of a circular rack. The other portion l51b has a number `of helically disposed. grooves, the two sets of grooves joining each other at the plane where the half-portions meet. 1 Also the helical grooves are of such form that each groove engages adjacent annular grooves of the opposite half-portion 51a. This member 51 is suitably keyed to the end of a constantly rotating shaft 52 so that it may be rotated at relatively high speed.

From this construction of worm 51,- only one-half of which is provided with helical grooves, it will be seen that the gear 50,I when it meshes with it will be rotated only while engaging the helical portions. hen the gear engages the annula-'rgrooved part, it is not rotated. The driving means for the indexing worm 51 may be provided from the main driving shaft 53 through suitable helical gears 54 shown diagrammatically in Fig. 1. The ratio between the reciprocations of the slide 3() and the rotations of the indexing worm 51 are,v in the illustrated embodiment, six to one, that is, the indexing worm 51 rotates six times while the crank :i4 reciprocating the slide 30 rotates but oui-e. The member 51 is mounted Von the block 4T carrying the rack 46,v its shaft being rotatably mounted within the block 17, The rotatable indexing member 51 is therefore adapted to be removable with the block`47 and the rack 46. A clutch 52a permits the shaft 52 to be easily disengaged from its driving shaft. `y

The gear 50 on the work spindle 38 is engaged by the rotating indexing member 51 only when the 'spindle .38 has been moved by the slide to approximately its limit of movement in one direction. The indexing member 51 is so positioned and timed that this occurs while the annular grooved portion 51"L is in position to engage theI teeth of the gear 50. However, while so engaged and while the member 51 is rapidly rotated, the gear 50 engages thehelical grooves 51b 'and so the gear 5() is rotated slightly. As

the slide 3() moves the spindle 38 on its return stroke, the Igear 50 and the spindle 38 have been indexed through the Space of one tooth. To accomplish this, the stroke of the slide 30`is adjusted to allow the gear 5() to' stay in mesh with the member 51 while it rotates slightly more than one-half revolution. During the period that, the

vmember 51 is engaged by the indexing gear 50, the helical projections 51" are engaged throughout their length.

Referring to Figs. .3 and 4. it will be seen the rotating member is adjacent one end of the rack and below it. Vhile the indexing gear is in engagement with the rotating member, the master gear is out ot' mesh from the rack so that the spindle can vbe rotated or indexed.

The feedingv action of the wheels 14 rela' tive to the teeth-of the gear A-being ground is preferably provided for by means to move the slides 11 away from each other to slightly separate the work engaging surfaces of the wheels. For this purpose, I provide a vertical shaft which may be rotated at an extremely slow rate of speed from suitable driving connections from the main driving shaft 53 and which rotates a spiral caml 61 upon its upper end. This spiral cam 61 is engaged by the rear end of a rod 62, the for-- ward end ofzwhich bears against the oppositely extending ends of two bell cranks 63. The bell cranks 63 are ivotally mounted in the base 10 about fixed axes 64 and their other andfishorter arms65 engage projections in the form of bearings strips 66 fas. tened to the under surface of the slides 11. It will be seen from this description that rotation of the spiral cam 6.1 will force the bell cranks 63 to oscillate slightly, thus forcing the slides 11 away from each other upon the ball bearings v12 provided for them. To return thefslides 11 to their normal positions, a spring .pressed plunger' 67 is provided adapted to'bear. against an adjustable abut-` vment 68 in the form ot' a screw in the base 10. Topositively limit the outward movement of the slides 1.1, a screw 69 is provided in the base engaging an abutment 70 on the slides. i

To manually operate the feed mechanism for the slides 11 and wheels 14, a hand wheel 71 is mounted on the end of a shaft 72, the oppositeI end of which is connected to the driving shaft 73 of a Worm in engagement with a. Worm wheel 74 on the lower endof vertical shaft 60. The shaft 60 and its -cam 61 may therefore be rotated by the hand wheel 7l or by means of the main driving shaft 53. To disengage the driving connections from theshaft 53 to the shaft 60, a lever 75 is provided, loscillation of which disengages a Worm 76 from a Worm Wheel 77 forming parts'of these connections.

What I claim is: A

l. A gear grinder comprising in combination, a base, a grinding Wheel rotatable thereon having a plane blank engaging surface, blank supporting and rotating means, means to simulate a rolling action of the blank upon its pitch circle by movement of said support in a straight line, means to index said blank at the end of its rolling motion in one direction, and means to continuously feed said the rolling motion o vthe blank in a direction tangential to the pitch circle of the blank.

2. A gear grinder comprising in combination, a base, a pair of obliquely disposed grinding Wheels rotatable thereon, blank supporting and rotating means, means to simulate a rolling action of the blank upon its pitch circle by reciprocatory movement of said support, means to index said blank Yat the end of its rolling motion in one direction, and means to continuously separate said grinding wheels during the rolling motion of the blank to eect feeding motions thereof.

3. A gear grinder comprising in combination, a base, a grinding Wheel rotatable thereon, blank supporting and rotating means, means to simulate a rolling action of the blank upon its pitch circle by movement of said support, means to index saidvblank at the end of each of its rolling notions in one direction, and means to continuously Jfeed said grinding wheel during the rolling motion of the blank in a direction tangential to the pitch circle of the blank.

4. A gear grinder comprising in combination, a base, a grinding wheel rotatably and adjustably .mounted thereon, a slide,

means to reciprocate said slide, a Work spin-- dle rotatably mounted on said slide, means to rotate said Workspindle simultaneously with movement of the slide so that a rollin motion of a blank on the spindle is simu ated, and means to continue the rolling and indexing movements of the blank While the wheel is slowly ted in a direction tangential to the rolling circle of the blank to completely grind the gear teeth to their, correct contour.

5. A ear grinder comprising in combina.- tion, a ase, a pair of oppositely disposedgrinding wheel duringV vments of the blank While the Wheels are slowly fed in opposite directions parallel to the direction of the rolling motlon of the blank to completely grind the gear teeth to their correct contour.

6. Indexing means for gear grinding machines comprising in combination, means to bodily move a spindle. having a gear blank thereon, means on said spindle adapted to intermesh with a 'rotatable member at the limit of movement of the blank in one direction, and means to rotate' said member in timed relation 4to the movements of the slide whereby a blank on said spindle will be indexed.

7. Indexing means-for gear grinding machines comprising in combination, means to bodily move a spindle having a gear blank thereon. means on said spindle adapted to intermesh With a rotatable member at thc limit of movementof the blank in one direction, a helical path on said member, and means to rot-ate said member in timed relation to the movements of the slide.

8. Indexing means for gear grinding machines comprising in combination, means to bodily move a spindle having a gear blank thereon, means on said spindle adapted to intermesh with a rotatable member at the limit of movement of the blank in one direction, an annular path on a portion of thc periphery of said rotatable member and a helical path on another portion of the periphery of said member, and means to rotate saidmember in timed relation to the movements of the. slide.

9. Indexing means for ear grinding machines comprising in com ination, means to bodily move a spindle having a gear blank thereon, means to effect a rolling movement of said lblank, a member rotatably mounted adjacent a gear on said spindle, and means to rotate said member in timed relation to movements of the spindle, said member and gear being in mesh at each movement of the spindle in one direction whereby said gear and spindle may be indexed.

10. A blank actuating and indexing mechanism for gear'l grinding machines comprising in combination, a reciprocatory slide having a rotatably mounted spindle thereon, a iixed rack. a gear on the spindle engaging Said rack whereby movement of the' slide will cause rolling movements of a blank on said spindle, a second gear on said spindle. and means adapted to be engaged therewith to index the spindle when said first mcntioned gear is out of mesh with said rack.

11. A blank actuating and indexing mechanism for geargrinding machines comprising in combination, a reciprocatory slide having a rotatably mounted spindle thereon, a fixed rack, a ear on the spindle engaging said rack where y movement of the slide will cause rolling movements oi ablank on said spindle, a second gear on said spindle, and constantly rotating means adapted to beengaged therewith to index the spindle each time said slide approaches its limit of movement in one direction. y

12. A blank actuating and indexing mechanism .for gear grinding machines comprising in combination, a lreciprocatory slide havin a rotatably mounted spindle thereon, a fixed` rack, a gear on the spindle engaging said rack whereby movement of the slide will cause rolling movements of a blank on said spindle, a second gear similar to the first gear on said spindle, and means adapted anism for gear grinding machines compris-vr ing in combination, a reciprocatory slidehaving a rotatably mounted spindle thereon, a fixed rack, a gear on the spindle engaging said rack whereby ymovement of the slide will cause rolling movements of a blank on said spindle, a sec nd gear on said spindle, and rotatable means operated in timed relation to the movement of said slide and engaging said secondgear at the end of the movement of the slide in one direction to index the spindle when said first. mentioned gear is out of mesh with said rack.

In testimony whereof, I hereto aiix my signature.

ARTHUR L. WILDER.

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