US1572926A - Grinding machine - Google Patents

Description

Feb. 16,1926. J. N. HEALD' ET AL GRINDING MACHINE Filed Oct. 7, 1922 4 Sheets-Sheet 1 @N @wi mwwwv @w mi d/W. @wauw .wo Z 7 Hmm ,musk idw/w, Iwem J. N. HEALD- ET AL.

Feb. 16 F1926.v

MACHINE GRINDING 4 Sheets-Sheet 2 [Ina/enfer?. 70.71295 NJCeczZd,

Filed Oct.

Feb. 16 ,1926. 1,572,926

J. N. HEALD ET AL I GRINDING MACHINE Filed Oct. 7. 1922 4 Sheets-Sheet 3 9229er? Jurner' eorace CJzm 77292 '552 www@ .Tann es .nlieald Pannes Feb. 1e, 192e.

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AMES N., HEALD, ALBERT TURNER, AND GEORGE C. .KIMMEL, O WORCESTER', MBtSSAHUSETTS, ASSIG'NORS T0 THE HEALD MACHINE COMPANYBYOF WOEESTER,

MASSACHUSETTS, A CORPORATION F MASSACHUSETTS.

onrnnrlue Maenner..

Application tiled October 7, 1922. Serial No. 593,113.

To all whom z't may concern:

Be' it known that we,y JAMES N. HnALD, ALBERT TURNER, and Gnonon C.. KIMMEL, all citizens oithellnited States, residing at Worcester, in the couhty of Worcester and Commonwealth of Massachusetts, have v invented a neiv and `useful Improvement in a Grinding Machine, of which the following, together with the accompanying drawings, is a. specification.

The present iiilvention relates to grinding machines, and particularly to improvements inthe construction and operation of the wheel feeding instrumentalities of' 'L machine forgrindng exterior cylindrical surfaces, although, obviously, not limited to a machine of such type..

The several features of the inventon are described hereinafter. and specifically pointed out in the appendedclaims, reference 'being had to the accompanying drawings, whereinv Fi 1 is a. view in front elevation of a grin ing .machine embodying the invention. Fi 2 is a similar view, on a larger scale,

showing the wheel feeding mechanism removed' from the front of the machine.

Fig. 3 is a top plan View of said mechanism.,

' 'Figa 4 is a transverse sectionalv view et said mechanism. f

Figs. 5 and (i are .respectively plan and sectional views of a mechanism for varying the stroke of a feeding pawl.

Figs. 7, 8 and 9 are large scale views, illustrating the operation of stopping mechanism, operable in connection with the leed of the grinding Wheel by hand, and showingr the parts in three (lider-ent positions.

Figs.- 10 and 11 are respectively front and sectional views on an enlarged scale, of anadjusting device carried by the hand wheel of the machine.

Figs. 12 and 13 are respectively front and sectional views of certain adjustable stopsadapted tobe used with said hand Wheel,

Fig. 14 is a plan'view, .partly in section, of afeed actuating mechanism adapted to operate independently of the travel of the table. p Figs. 15 and 16 are tient views ot said feed actuating mechanism, showing 1t respectivelyin operative and inoperative position.

tween centers l and 5 provided, respec-A tively, by a head stock 6 and a tail stock fl, both carried by table 3 and adjustable thereon to 'accommodate pieces of work'o die'r-V ent lengths. -The head stock (i provides the usual means, not shown, for engaging the work, and rotating it on the laxis provided by the centers 4 and 5; this rotation, in con- ]unction with the simultaneous reciprocan tion of the Work afforded by movement of table 3, subjects all port-ions of lits surface to the action of a rotating grinding wheel 8, which is suitably journalled in a head or slide 9, the latter, -by its movement in suitable transverse' ways 9, Fig. L1, procurng the feed of the grindingwheel toward and from the work axis,

" The movement of table 3, tocarry the ro tating work back and forth in contact with the grinding wheel 8, may be effected by any desired means, suchas a fluid pressurecontrolling and reversing mechanism of the type, for instance, disclosed in the 'cepending applica-tions of Drake & Hubbell, Se rial No. 528,118, fileddanuary 9, 1922, and Heald & Turner, Serial No. 574,940, filed July 111, 1922. The construction and operat`on of this mechanism, for' reciprocating the work' forms no part of the present invention it being suflicient to 4note that a reversing valve for the motive fluid', not shown, is operable by a lever 10, the lat ter having a pin and slot connection, likewise not shown, with a rocking member 11, whose upper end projects into the path of a pair of adjustable dogs 12 and 13 rcarried by the table 3. These stops or dogs 12 and '13 engage the membery 11 alternately whereby to reverse the direction of travel of the table 3 at each engagement; their longitudinal adjustment .determines the throw', or length of table travel, for any given operation.

The cross-leed movement 'of wheel head 9 is obtained by the usual main screw shaft; 14, Fig. et, which cooperates with a nut 14C- contemplates .thel feed of the grinding WheeltoWa-rd the Work in responseJ to the reciprocatons ofthe table 3, the stops or dogs 12 and 13 being utilized for successive actuations of the Wheel feeding mechanism to procure .a predetermined feed of the 'grind'- ing Wheel after each traversing movement of the Work.

To this end a member 15, pivoted to the machine frame yat 16, carries a roller 17 which isdisposed in the path of projections 18 and 19 provided respectively by the dogs 12 and 13. A .link 20 connects member'15 to a rocker arm 21, the latter adapted to swing on the axis provided. by a shaft 22, on which is also journalled a ratchet wheel A spring 24, attached to arm 21, acts yieldingly to draw said arm about its axis in a clockwise direction, Fig. 2, and thus holds the roller 17 of member 15 in position to be engaged by the travelling projections 18 and 19. These projections, at each engagement with roller 17, act to depress the free end of member 15 and thus, through link 20, to

rotate the arm 21 counterclockwise througha small'arc; a pawl 25, carried by said arm,

operativelyngages the teeth of ratchet Wheel 23, and thus efects a counterclockwise rotation. of said ratchet Wheel through the same arc. On the return movement of arm 21, under the inuence of springl 241, the pawl 25 simply slides back inoperativcly over the ratchet teeth. The hub of ratchet wheel23jis extended inwardly to provide a pinion 26 which meshes with a gear 27 on main screw shaftll; in this way, each angular displacement of ratchet wheel 23 is communicated to the feed-screw, to effect a lateral shifting of the wheel head 9; the feedscrew however has only a very small angular movement,` in comparison to the angular movement of ratchet Wheel 23, because of the gearing 26, 27,-the arrangement being' such as to require, for instance, ive complete revolutions of theratchet wheel for one revolution of the feed-screw.

At each engagement of the roller 17 with' the traveling projections 18 and 19, the member 15 isalways depressed to the sameI level, dueto the fact that no further down- Ward movement of the roller,17 can be produced by further movement in either direction' of the table 3, after said roller reaches the horizontal alined surfaces 18 and 19"of said projections. In this Way, the operative stroke of arm 2l is made to terminate always at' the same point, and thus the feed of ratchet wheel 23 by pawl 25 is not subject to any vsuch accidental -variationias would be apt to result from the table 3 travelling at a nwaeee In'conjunction with the above described` means forinsuring the stoppage of pawl 25 always at the same point on its operative v stroke, the invention provides means for adjusting thetravel of said pawl on its return tir-inoperative stroke, whereby the operator Ais enabled to .tix Withl exactitude the number clockwise movement of arm 21, under the influence of spring 24,. is subject to limita- -tion by means of an irregular rotatable cam 28 disposed in. the 'path of a projection 29 of link 20, Fig. 5, The cai1'28 is journalled on a stationary stud 30, as shown in Fig. 6, and is provided with suitable means for turning it by hand such as aknob 31. `A spring pressed Vpin 32., cooperating with 'suitable shallow depressions' in the bottom of cam 28, insures the correct disposal of said cam in the various positions of adjustment to which it may be turned, for the purpose of opposing its high, low, or intermediate portions, as desired, in the path of projection 29. The handle 31 is preferably so inscribed as to indicate the adjustment of the. cam 28, with reference to an index marl:

-on the stud 30, as shown in Fig. 5,-thus luc nalled on shaft 22, the same as the ratchet wheel 23 Said hand Wheel 34.- has secured thereto a radially .disposed bracket 35, Figs. 10 and 11, Which provides a journal portion 36 for the reception of a rotatable member 37, the latter adapted to be turned by a knob 38, Fig. 10. The connection of knob 33 to member 37, for turning the latter, is by means of a spindle 39, secured to said handle and keyed to said member; the spindle 39 provides a normally projecting toothed por` tion 40, adapted t@ mesh with the teeth of ratchet wheel 23. A spring pressed pin 41, 'adapted to enter a seriesof notches 4t2 provided by member 37, operates as a friction lock to prevent accidental',displacement of member 37 and spindle 39-and thus serves to insure rotation'in' unison of hand wheel 34 and ratchet wheel 23, except when the handle 38 is seized and turned on its own LTI . to lock the hand wheel and ratchet wheel tothe compression of a spring 43, which nor-4 mally holds the pinion teeth and ratchet teleth in engagement, as shown in Fig. ll,

gether. p

The hand wheel 34 carries on its periphery an inwardly projecting plate or shield 44, Figs. 2 and l0; this shield 44 ispret.

erably, though not necessarily,` carried by the bracket 35 of said hand wheel and, be-

' ing disposedl in overlying relation to the ratchet teeth of wheel 23 is adapted, when carried into the zone of action of pawl- 25, to prevent operative engagement of said pawl with said ratchet teeth. In other words, the shield' 44 may be set or iixed to intercept the lpawl, following a predetermined automatic 'leed of the grinding 'wheel by said pawl, whereby-to' discontinue said leed as soon as the work has been ground down to a predetermined diameter.

With the ratchet wheel 23 inthe exact position thatit assumes v'lor agiven desired diameter, the handwheel 34 is adjust/ed, re1- ative to the'ratchet wheel 23, to bringthe shield 44 into position for just intercepting pawl 25; this 'is doneby-retra'cting knob 38 i so as to allowjfree movement of the hand wheel without disturbing the exact setting of the ratchet wheel. Thereupon, the knob l38 is released, allowing thev hand wheel and ratchet wheel to be locked together again by the meshingrfo'f pinion teeth 40 with the teeth of the ratchet wheel. l/Vith the 'shield 44thus adjusted in iixed relation to lil() a predetermined tooth on the ratchet wheel 23, the grinding wheel 8 can be fed backward to allow the introduction of an unground piece of work; with tlns setting of the shield 44 maintained, subsequent auto# 4matic feeding of the grinding wheelby 'the "action of paw/ 125 is always interrupted at the proper time, to prevent the work from l jrun back the hand wheel throng just-mentre useful not alone in obtaining the exact setting of shield-44, but can also be availed of to readjust said shield troni timeto time, torompensate for the gradual wearing down of the surface of grindingv wheel 8.

ln another' of itsaspects, the present inf vention contemplates improved means `for feeding to exact predetermined size, lwhen the feed -ot'the grinding wheel is obtained; by hand,`-t hat is, by rotatlonofthe hand wheel 34, to obtain a straight grinding cut on work that. does not require any traversing movement across the perlphery of the grind- 1n wheel. In the operation of` feedin the "grlnding wheel by hand, as above described,

the -attainment of the desiredv diameter 'for an initial piece of work leaves the ratchet wheel 23 in the exact .position necessary for it to .assume for all subsequent reproduci tions of the same desired diameter; and ybetion -45 carried by hand wheel 34,' an'dpreferably, though not necessarily, extending from the bracket 35 of said hand wheel, said .projection 45 cooperating with a stop which is here shownas constituted by the end of a lever 46, adapted to be interposed in the path of said projection. Theprocedure is as lollowse-Without disturbing the above described .final osition of'ratchet wheel 23, the hand wheel 4is turned to carry the projection 45 into exact engagement with thecnd of levere46; this may be done by revolving knob 38 to click or rack the hand lever 34 through the necessary diss tance, but is preferably done much more quickly by retracting the knob 38 and then t|;| rning the hand wheel freely counterclockwise until the projection 45 and stop 46 como together, following which the return ot knob 38 toits normal position again locl-:s'the hand wheel and the ratchet wheel together for movement in unison. -There upon, the' grinding wheel .is :ted backward, by clockwise rotation iof the hand wheel, to permit the insertion of a new'unground piece of work, and it is obvious that, unless it vhas been necessary, for this pur ose, to

y more than one revolution, the new piece of work,

land other subsequent pieces, will be brought to exact .size when the projection 45 again engages the interposed stop 46, to prevent lfore 'the grinding wheel is fled backward further lcounterclockwise rotation of the I hand wheel. f

1 However, itlrequently happens that the opera-tor must run the hand wheel 34 back through more thanone revolution in order to insert the 4new piece of work between. .the centers 4 and 5 under these conditions, the stop lever 46, if maintained in the path of projection 45, would.. bring about the stoppage ot the hand feed too.soon,-that is, with the hand wheel still having one or more revolutions-to. make beore..the work would Vbe ground to the desired size. The present invention contemplates an automatic'control fof the stop lever 46 to'take care of this conf tingency; to this end, said lever is pivoted for movement about an axis provided by a stud 47, and has secured thereto an arm 48, whose end rides in contact with an irreguy lar'cam 49. The cam 49 is carried by an outd fed backward inthe usual way by the move? ward extension of the main feed screw 14, being normally rotatable with said feed screw, at a speed much reduced from that of the ratchet wheel and hand wheel, by the" The cam 49 presents for successive contact with arm 48, an extended concentric portion 52, a lower-portion`53` and a high point 54. When the above ,described setting of projection 45 is made, for the purpose of stopping further inward feed upon. the ratchet wheels travel to a predetermined position, the cam 49, at the same time, is

turned .onfscrew shaftg14 into the position shown in Fig. 7, where the lower portion 53 'opposes the arm `48, and .where a spring pressed pin carried by arm 48, bottoms in a stationary notch-56,;whereby to retain the end of lever 46 in the path of projection 45. Following this setting, the grinding Wheel is ment of hand .wheel 34 and ratchet wheel23 in unison such movement causes counterclockwise rotationof cam- 49,v to bring the concentric portion 52 -of said' cam "against the arm 48, and it is particularly to be noted that th gear reduction above described, between '.the parts, isv such thatv several complete revolutions of the hand wheel can be made without disturbing thisrelation, i., e.,

the travel of arm 48 on concentric portion 52, as shown in Fig; 8. ,l f

Inthis position of' the parts, the end of stop lever 46 isheld just out of thefpath of projection 45, as shown inf Fig 8, with the spring pressed p in 55` partially withdrawn from the stationary notch 56? lThus, 'on the return or inward feed of .the grinding wheel, by the '.-counterclockwise rotation'- of `hand wheel :34, the cam-49 holds the stop 46 in inoperative position through the same desired number of revolutions of the :hand

Wheel; on the last revolutidn of this inward hand' feed, the low portion 53 ofthe cam comesjop'positethe arm 48, and the pinv 55,"

by bottoming in notch '56, throws the end-of stop lever- 46 into operative position in the path "of projection 45,c vvlt-is to be noted in this connection that the low'portion y5? of the rotating eccentriccontact cam 49 isextended to embrace a considerablearc; vthis permits the above described action to take place notwithstanding such further line adjustments as are made from time to time by rotation of knob 38, to compensatefor the gradual wear of the grind# infr wheel.' Y

rom t-he foregoing, itwi'll beclear that the hand feed stopping mechanism is so constructed as to automatically and properly control the position of stop 46 in feeding opera-tions that require several complete revolutions of :the hand wheel,in this case, for.ins tance'say five revolutions, as determined bythe five-to-one gear reduction between the' hand wheel and the main feed screw 14'.: lnhsuch cases asrequire more than five backwardturns of the handwheel, i. e., one ,complete revolution off-cam 49, the high point 54 of said cam'strikes the arm 48 and throws'tlie pin .55 out of notch 56 and into .fan adjacent notch 57, as shown in Fig.. 9,

thus rendering they stop 46 wholly inopera-v tive, and requiring its return by the operator tonormal position after the vinward feed. of the grinding Wheel has progressed .far

enough to bringcam portion 52 opposite the arm 48., y

In still another of its aspects, the invert-y tion'involves mechanical means for procuring .the feed of the grinding wheel on straight in-cuts, i. e., when there is no traversingofj the wheelby the work and hence .no engagement of member-15 to actuate pawl i 25, Under these conditions, the-drive. for

the feed is from a suitably journalled rotati ing shaft 58, Figs. 3, 14, l5 and '16," said shaft. being driven in any suitable manner as bygmeans of a sprocket wheel 59 thereon which may be connected by 'asprocketcliaim not shown, with a suitable driving sprocket on the main shaft of the machina-not shown. On-one end said shaft 58vcarries an eccentric pin 60, the latter projecting into the hole or opening 6l of a member 62, and carrying fa contact roll 63, The vmember 62 is pivote at64 to the arm 21,- and in one sition ,of Y said member, asnillustratedvin j spring pressed pin 65, engageable ing'a notch. provided by extension 6 6' of arm 21, main? tains said member 621undertlieinduence of roll 63,whercby .to produce the oscillation of-lever 21 and the consequent automatic feed ofthe grindl I pawlv 25 and ratchet-120ling wheel, through d wheel It wil 'be understood'J that the limiting mechanism shown in Figsiv 5 and-6, heretofore described in connection with the table 'feed of the. grinding-wheel, is' also op ,eral:i le,v under the'seconditions, to produce. a line, coarse, or medium f feed of wheel., lVhentheftahle-feed is l when' 'it isf" desired to'.feed-` byfliand instead of .f mechanically, .thepin 65. y isretracted, land the member 62fs swung?. upwardly on its" the grinding operative, orf

pivot 64 into the position shown in Fig. 14, I'

where the pin 65, entering another notch in extension 6G, retains said member 62 out of contact with the rotating ecccntrically disposed contact roll 63. In connection with this type of mechanical feed, which is useful more especially in grinding short pieces that do not require traverse of the wheel,

piece of work, it is of advantage to use, in

connection with the stop 46, a plurality of cooperating devices 67, (57, adjustable on the periphery otv hand wheel 34, as shown in Figs, .l2 and 13; l Each device G7 is made in two partel `and said parts are adapted to be drawn together by a screw GS, which serves to retain the device in the desired position of adjustment on the periphery of the hand wheel. Each device G7 provides a projection ,(31), for engagement with the stop 46, and the several devices are so 'spaced apart on thev hand wheel as to procuie successive stoppages of the hand feeding as each diameter,

from the largest to the smallest is reached,-.

il. being understood, of course, that' following stoppage of the feed in each case, the work is shifted longitudinally and the stop lever 4G is rocked by hand to allow a projection 69 to pass, and then returned to operative position into the path of the next projection 69. Where the difference in diaiiieter is ver)v small, provision is made for a close setting` of the adjacent devices G7, G7, by using one of them with an oblique side, as shown at TO, Fig. l2.

ll'e claim:

l. ln va grinding machine, Wheel feeding mechanism comprising a ratchet-wheel operatively connected to the main feed screw, a hand wheel concentric with said ratchetwheel and a 'rotatable pinion cariied peripherally by said hand wheel and movable into and out of mesh with the teeth of said ratchet-wheel, in combination with a cylindrical membcrof larger diameter than said pinion and rotatable therewith, said meinber having a series of spaced peripheral dcpressions, and a spring-pressed pin adapted to enter said depressionsto restrain rotation of said pinion, whereby to' form as ubstantially positive lock between said hand wheel and said ratchet-wheel except when said pinion is seizedand axially turned to overcome the frictionof said pin, in the act of adjusting the hand wheel relative to the ratchet-wheel. l

2. In a wheel Afeeding mechanism for grinding machines, a main feed screw, a'

hand wheel, means for normally operatively connecting said hand wheel and said main feed screw, a stop, and a projection carried by the hand wheel, the latter being movable,

-When desired, independently of the main.

feed screw to procure engagement of said projection and said stop in a predetermined work-sizing position of the grindingl wheel, in combination with a cam opeiable on said stop, and rotatable, at 'a reduced speed, from said hand wheel, said cam providing a relatively short portion corresponding to the operative disposal of said stop in the path of said projection, and an extended concentric portion adapted-to maintainvsaid stop out of the patliof said projection until said hand-wheels final revolution, in bringing thefgrinding wheel to said predetermined position, is reached. i

3. In a Wheel feeding mechanism for grinding machines, a main feed screw, a hand wheel, means for normally operatively connecting said hand wheel and said main feed screw, a stop, and a projection carried by the hand wheel, the latter being movable, when desired, independently ofl the main feed screw to procure engagement of said projection andv said stop in -a predetermined Worlesizing position of the grinding wheel, in combination With a cam operable on said stop, and rotatable, at a reduced speed, from said hand wheel, said cam providing a rela tively short portion corresponding to the operativedisposal of said stop in the path of said projection, and an extended concentric portion adapted to maintain said stop out of thepatli of said projection until said hand-wheels final revolution, in bringing the grinding Wheel to said predeter- `mined position is reached, and said cam further providing a projection adapted to render said stop. inoperative. when the hand wheel, in backward feeding,` is turned through more revolutions than the number corresponding to a single revolution of said cam.

4. In a wheel feedingv mechanism for grinding machines, a main feed screw, -a hand wheel, means for normally operatively connecting said hand wheel and said main feed screw, a stop, and a projection carried by the hand wheel, the latter being movable, when desired, independently of the main feed screw lto procure engagement of said projection and said stop in a predetermined worlesizing p'osition of the grinding wheel, in combination With'm'eans operable during subsequent inward and 'outward operative feeding revolutions of the hand wheel for 'n'iaint-aining said stop out of the path of said projection until said hand-'Wheels final revolution, in bringing the grinding wheel` to said predetermined position, is reached,

said means comprising a cam frictionally driven from the main feed screw, and shiftable angularly thereon.

5. In a wheel feedingmechanism for grinding machines, a main feed screw, a hand wheel, means for normally operatively connecting said hand wheel and said main feed screw, a stop, and a projection carried by the hand wheel, the latter being movable, when desired, independently of the main feed screw to procure engagement of said projection and said stop in a predetermined work-sizing position of the grinding wheel, in combination with means operable during subsequent inward and outward operative feeding revolutions of the hand wheel for maintaining said stop out of the path of said projection until said hand-wheels final revolution, in bringing the grinding wheel to said predetermined position, is reached, said means comprising a vcam frictionally driven from the main feed screw, and shiftable angularly thereon, said cam having a depressed portion corresponding to f the operative disposal of said stop in the path of said projection, and said depressed portion beingextended to permit fine adjustments of predetermined work-sizing position of the grinding wheel, to compensate for wear of the latter.

6.' In a wheel feeding mechanism for grinding machines, a main feed screw, a hand wheel, means for normally operatively connecting said hand wheel and said main feed screw, a stop, and a projection carried by the hand wheel, the latter beingmovable, when desired, independently of the main feed screw to procure engagement of said projection and said stop in a predetermined work-sizing position of the grinding wheel, in combination with a cam operable on said stop, duced speed, from said hand wheel, said cam providing a relatively short portion corresponding to the operative disposal of said stop in the path of said projection, and an extended concentric portion adapted to maintain said stop'out of the path of said projection until said hand-Wheels final revolution, in bringino the grinding wheel to said predetermined3 position is reached, and said cam further providing a projection adapted to render said stop inoperative when the hand wheel, in backward feeding, is turned through more revolutions than the number corresponding to a single revolution of said cam, ,and a spring pressed pin carried by said stop, fory cooperation with a pair of notches, to retain said stop in the respective positions to which it is moved by said cam.

Dated this third day of October, 1922.

JAMES N. HEALD.A ALBERT TURNER. GEORGE C. RIMMEL.

andl rotatable, at a re

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