US2436588A - Cam grinding machine - Google Patents

Description

. Feb. 24, 1948. J. MARTIN ,4 CAM GRINDING MACHINE k Filed Aug. 2, 1945 e Sheets-Sheet 1 1 564 INVENTOR.

E l: g L. BY

Feb. 24, 1948. MA RTiQI 2,436,588

CAM GRINDI/NG MACHINE Filed Aug. 2, 1945 6 Sheet's-Sheet 2 l N V EN TOR.

19' Tran/v5 Vs Feb. 24, 1948. J. MARTIN I CAM GRINDING MACHINE Filed Aug. 2, 1945 6 Sheets-Sheet 5 INVENTOR. mxryes Mfi/Zzlfi- BY Mia-4% Feb. 24, 1948. J, R-rm CAM GRINDING MACHINE 6 Sheets-Sheet 4 Filed Aug. 2, 1945 INVENTORQ 7 r Tal /v5 Vs,

Feb. 24, 1948. J. MARTIN 2,436,588

CAM GRINDING MACHINE Filed Aug. 2, 1945 6 Sheets-Sheet 5 v I INVENTOR.

J2me: Marill},

CAM GRINDING MACHINE Filed Aug. 2, 1945 6 Shqe ts'-Sheet 6 Patented Feb. 24,,

J "elistisss" v CAM GRINDING" MACHINW iafiie Martin, ieiiiattie, Mich; aseignbr' tion' of Delaware T061 company, Detroit; Mich; 2t corpora:-

mutation August 2, 1945, serial No. 665,475

ez talli? t eta-st rly, it relates to a subchine for grinding ma.-

finished product. In order-that the cam perform satisfactorily, it essential that i the, contour thereof be accurate and the surface be highly polished;

Heretoiore, to; obtain the; accuracy andifinish a fi 1 W.as adapted to. the carnecessary, riage'o'f a grinding machine. Inasmuch asv the operation wasnot suited to; a grinding machine, considerable set-up and operatingtime wasrequired, resulting in appreciable costs;

In adaptations of, this; kind; much. depended" upon the skill and ability of the operator and" it is obvious that only an oper'ator having years of experience could be' relied upon' to obtain uni formly accurate results.

is to provide animprove'd machine for' automatically and; accurately grindingcams having a uniform rise, and to provide a machine which is in no way dependent upon the'skill or ability of the operator.

Another object of: invention'is' to provide a simple-compact, yet. at'the same time precise,

which will eliminate the afixtureto a-grinding ma'chine'for the tion of uniformrise cams;

Another object-of theipresent invention is'to' provide a novel andimproved construction of this type which requires but slight adjustment to produce the desired-vrisei on'cams. In order to accomplish this. result, the present invention" contemplatesutilizingan adjustable 1 rack re"- quiring only a chan'gein s'lope: to 'ad'apt a chineof this construction" to produce; such cams vide a construction of this The primary objectoh present invention theigri ndihg' wheel, automatically reconstantly mes hes "a'rci procating rack at In order to accomplish this, 'a' roll pitch liner v a V of the" sam'eu ameter' as, the pitch circle of the gear is provided'l'tojroll an adjustable sine; bar, reciprocating with the rack, the heightof, the same. as the pitch linethe sine bar being of the rack.

- A Still waiter la t. tithe} present in ention Is to provide -a"nove1 andimprovewconstruction' I p ren f eih $1 ciprocates I to I the wqr e aac es P i Other objects of th' the drawings relating hereinafter set forth.

In the drawing used to indicate like parts wherever indicated:

plane of rotation of e o f the same.

'nvention will become owing specification. from thereto, and the claims odying the improvements of the taken substantiallygon theline 3 -3 of Figure 1,

showing the'grindin'g wheel motor and driving 7, i ,1. 5 J. V, 1 Figure 4 isla',vertical, sectional view taken on the line 44 of Figure 1, showing the stroke carriaee linka a, t

F ur is a s ctiena 'Y ewtaken substantia ly on line 5 5 Figure 4 showing the feed caree nkaeet e FigureG is a yertical; sectional view taken on hel e rie iE surelrshowine the ear and k or mo vat n the, workp e e. l

Figure 'Zisa section through the stroke carriagetaken on'line 1?! of Figure 6.

Figure8 is a sectionr on line 8,-.8 of Figure 5.

, Figure 9 is a section taken on line 9--9 of Figure4. t

,In' the present invention; vided by which a uniform as a high-speed grinding" a' construction is prorise cam is developed wheel automatically reciprocates acrossrthesurface of a workpiece,

mounted .on' a spindle. for'intermitten't rotation in one direction and then the reverse.

of" aigear secured "to the spindle, the teeth of said gear engaging-1 those. of, an automatically cam the required rise;v As the rack reciprocates; the sur face of'theiworkpiec presented to the grinding reciprocating, "sloping" rack to give the wheel is ground" and'poli'shedto the desired contour. t

Fora'mor detailed"description of the iriin whichabaseisgneially indicated at I.

support In the camgrindi'ng' apparatus, and

houses the drivingzme'chanism both of which are hereinafter described in detail, 7

s, m which like numerals are Rotation in this manner is imparted to the blank by means It will become apparent from the description which follows that it is necessary to provide for reciprocation and sloping adjustment of a rack 2 in order to accomplish rotation and movement of a workpiece 3 in the plane of rotation. To.

accomplish this, carriage 4, hereinafter termed a stroke carriage is provided. Said stroke carriage 4 is mounted on an upper part of base I for reciprocation upon machined surface 5 and slideway 6. Such carriage is provided with upwardly directed projections I, 8, providing mating holes through which a pin 9 extends to secure arcuately adjustable table in thereto. At the opposite extremity, said carriage is further provided with upwardly directed projections II, I2 with curved slots I3 therein, one of which is shown in Figure 6. Such slots permit bolt I4 to pass through a mating opening of table I!) in such manner that said table may be arcuately moved to, and fixedly held in, asloping position when nut I5 is tightened' to press washer I6 against upwardly directed projection I I.

Rack 2 is secured by means of bolts I! to said adjustable table for adjustment into a sloping position therewith. Said rack has teeth I8 meshing with teeth I9 of gear pinned at 2| to spindle 22 for rotating thesame as rack 2 reciprocates.

In order to prevent binding of the teeth upon reciprocation of rack 2, provision is made to engage such teeth at their respective pitch lines. To accomplish this, a sine bar 23 is mounted adjacent to rack 2 on adjustable table I0 by means of bolts 24. Surface'25 of said sine bar engages peripheral surface 26 of roll 2! which rotates freely on spindle 22. i The height of sine bar 23 is equal to the height of the pitch line of rack 2, and the diameter of roll 21 equals that of the pitch circle of gear 20. Thus, it is obvious teeth I8 and I9 must engage at their respective pitch lines.

A workpiece 3 is rigidly secured to an extremity of spindle 22 between shoulder 28 and nut 28 which threadably engages said spindle.

It will be observed that as rack Z-reciprocates with carriage 4, intermittent rotation in one direction and then the reverse: will be imparted to workpiece 3 by means of gear 20 andspindle 22. It is pointed out that said rack is made equal in length to the circumference of the pitch circle of gear 2!! in order that each stroke of said rack will present the entire peripheral surface of workpiece 3 to grinding wheel 30. It is to be furtherobserved that rack 2 is shown in a neutral or lowered position in Figure 6. In operative position, however, said rack must be sloped to give rise to the cam. This being true, gear 29 will move in the plane of rotation as rack 2 reciprocates, and such movement will be imparted to said spindle and workpiece.

Spindle 22 is supported by movable arm 3| to provide for said planar movement. Such arm 3I is pinned at 32 to standard33 upwardly pro? jecting from base I and provides bearings 34, 35 for bushings 36, 31, 38 which retain said spindle.

Tension springs 39, 40 prevent gear 20 and rack 2 from disengaging as said rack reciprocates. Said springs, held by pins 4| of clevis bolts 42 secured to base I, are attached to bosses 43 of arm 3|. Such arm 3I thus forcibly urges gear 20 to mate rack 2 continuously, regardless of the sloping disposition of said rack.

Although gear 20 is constrained by spindle 22,

i the relative movement between the gear and rack, as said rack reciprocates, produces in effeet the same result as though said gear were permitted to roll and said rack were stationary. Therefore, as gear 20 in efiect rolls on rack 2, it rises uniformly from one extremity to the other thereof, and the surfa ce presented by workpiece 3 to grinding wheel 30, as said wheel reciprocates across said surface, is that of the curve traced by an imaginary point on the pitch circle of gear 20 as it rolls. The slope of rack 2 represents the total rise of the cam and it is apparent that this need only be changed to adapt a machine of my invention to grind cams having different rises. It is also apparent that this adaptation may be made quickly by even an inexperienced operator through use of bolt i4 and nut I5. In this manner, a cam grinding machine of my invention has, by the simple expedient of varying the slope of a rack, made possible the production of uniform rise cams having different rises, and eliminated the necessity of elaborate, expensive adaptations which only a skilled operator could control.

Grinding wheel 30 is mounted upon carriage 44, which is hereinafter termed a feed carriage, to reciprocate therewith. Said carriage is mounted upon base I by means of machined surface 45 and keyway 4'6 for reciprocation in a plane normal to that of stroke carriage 4.

An upper portion of said feed carriage forms grinding head 41, withmachined surfaces 48 and slideways 49 adapted to receive slide 50. A lower portion of slide 50 forms at 5| one-half of a housing for bearings 52. 53'which support grinding wheel shaft 54. A cap portion 55 secured to portion 5| by bolt means 56 forms the other half of the housing for said bearings. The generally annular, cylindrical, abrasive grinding wheel 30 is affixed to the extremity of shaft 54 adjacent stroke carriage 4.

To provide for adjusting said grinding wheel into contact with the workpiece, nut 51 is appended to the rear of slide 5|] by bolt means 53 to threadably engage portion 59 of feed screw 60. An upper portion of said feed screw 63, secured in suitable bearing means 6i, carries bevel gear 62 pinnedthereto at 63. Such bevel gear 62 mates bevel gear 64 on shaft 65 which is supported in suitable bearing means 66. A handwheel 61 is mounted on said shaft 65, which when rotated, rotates shaft 65 and bevel'gear 64 and in turn bevel-gear 52. As bevel gear'62 is turned, it is apparent that slide 50 will move as nut 51 travels along portion-59 of feed screw 60. Thus, by means of handwheel 61, grinding wheel 30 may be positioned with respect to workpiece 3.

Electric motor 68, mounted on feed carriage 44, drives grinding wheel 30 only. It is pointed out that such motor reciprocates with said carriage and is not operatively connected to the driving mechanism. to be later described. As motor 68 is energized,'motor shaft 69 rotates pulley Hi. Pulley 'lfl'drives compound pulley II by means of belt I2. Said compound pulley drives pulley I3 mounted on' grinding wheel shaft 54 by means of belt I4. It is obvious that pulley sizes may be selected to drive grinding wheel 30 at any speed desired.

To accomplish reciprocation of stroke carriage 4 and feed carriage 44 intimed relationship as described, suitable driving mechanism is provided. A prime mover in the form of an electric motorIS is mounted at IS in a lower portion of base I which has been previously described. When operation is initiated by starting motor I5, motor shaft 11 rotates pulley l8. Pulley I8 drives aaeeissfai pulley 7.9,;shaft -8fix and worm 8l by. means of belt82. WormB-i =drives worm gea-r 83= andshaft 84 extending. therethrough :t-oxdrives at one ex.- tremitycrank- 85*"with .crankapintfi and, at the opposite, worm .81; orm-81 drivesworm gear 8.8'which in turndrives shaft: 89 and crank 90 with crank; pin 9!.

Suitable mechanism is provided-:to accomplish reciprocation of stroke carriage 4 ascrank pin 86 rotates. Said'pin passes-through opening 92 of .slide' biock.:93, positioned to-move slidably "in I-slot 94 of oscillating. lever- 95;: It is-pointed out thatcrankpin 86 istnot tight in'zopening -92, but is free to rotate.

Aniupper end of-lever Biprovidesslot 96; adapted to slidably receive block 97-. :Said upperend and block Mare received in channel aB' form'ed between the .clownwardly" disposed sides 99; 1-00 of channel block llwhichqdepends from stroke carriage .4. By means of a pin [02 extending through mating holes-in blockfl'l and'said downwardly extending sides, said block is retained therein. Thus, as crank-pin86 rotates; slide block 93 reciprccates in I-slot 94 and-lever 95 oscillates about bearing. 103, reciprocating. carriage 4 .by means of block 99=pinnedto channel-block I'OI.

Similarly, suitable mechanism is provided to reciprocate feed carriage 44. normal to the plane of reciprocationofjstroke carriage 4as crank pin 94: rotates; Said crank pin extends through opening 104 of slide block- I05. An I-slot 106, in lever I01 is providedfor saidblock to slidably reciprocate therein. At theitop of lever l07,.a slot I 93 is provided to receive block' I09. Channel block H0 depends'from feed carriage 44 and has downwardly disposed sides. HI, I I2, forming channel H3 in which to receive saidupper part of lever I01 andblock I09; Said block I09 is re-' tained. therein by means ofpin 4 passing through mating: holes in sides H1, H2 of said block. Lever-I01 is mounted to oscillate about bearing l'l5'atits'lower extremity-L Inasmuch as the operation is similar tothat described for reciprocating stroke'carriage-4',:it will not be further described.

It will be quite apparent to those skilled in the art that feed carriage 44"must be reciprocated more rapidly than stroke carriage 4 to accomplish the grinding and polishing of an accurate cam contour with reasonable rapidity. It is equally obvious that this result maybe readily accomplished by providing in the driving mecha nism suitable gear *ratios and lever lengths to provide for reciprocation of the grinding wheel many times-asthe workpiece rotates in either direction. In the machine'described herein,the

ratio of reciprocationeithefeed carriage to that of the stroke carriage is" 30 to 1. This, however, may" be made any figure consistent with good practice without departingifro'm the described invention.

f Formalchangesmaybe made 'inlthe specific embodiment of the invention described without departingfr'om' the spirit and substance of theinvention, the scope of which is commensurate with the appended claims.

, What isclaimed' is:

. 1.. A. machine for grinding uniform rise cams comprising a base, a spindle mounted on said base to rotatablyisupport. a workpi sa dsp ndle; ad pted. to permit movement. of the workp ece in the plane, of rotation, a feed carria e mounted on. said base forrecipr 'cation normal to the" planeiof rctationlof said-w rkpiece, said; carriage" including a generallr'cylindrical, an-

associated with said spindle: forxefiecting rota-r tion thereof, a: rack: on zsaids stroke carriageto engagezsaidzgearilforaefiectin rotationrandmove ments or. ;'said iworlepi'etie :izrxitstplane of rotation in: accordance with saidrrecipriocating movement; the combinedcmtationalsandiplanarismovements serving to cause'sthe :peripherali surface of the workpiecez'toiprogressivelyicontact ithe'surface of the grindingwwlieel-w along z-thei contour 2 of. a. uniformcrisescam;'and common driving means: t'oreciprocate said :vfeed i'carriage and said: stroke carriage" in:v timed relationship.

2.. A machineforgrinding uniform rise camscomprisinga base aazspindlefimounted on .said' baseto rotatably ,upportaworkpiece, said spindle adapted topermit movement of the workplecevin the plane-20f rotation=,z'a feed carriage mounted-on saidxbase-r. for 1 reciprocation normal uto" the1'1plane-soft rotation of said work!- piece; said carriageinc'lflding apgenerally' 'cylin drical' annular; z'grinding wheel andimeans "for driving same, a stroke carriage mounted'on said basesfor. reciprocationaxin: avplane parallel to the plane: of rotation of -said'workpiece', saidi stroke carriage including: an adjustable rack and means for adjusting thesame-to alslopirigposition; a:

gear securedvtmsaidzspindleafor e'fiecting rota tion thereof; said sloping rackonsaid stroke carriage; engaging said gear for effecting: rotationin accordancewith said reciprocating movew ment, the combined rotationalzand planar movements serving tmcmitact-the surface of the grinding wheel along the -contour of a uniform rise 'cam, and" common driving-means to'recipro-' cate: said feed" carriage sand said strokecarriage in itimed relationship.

3; A ma'chine' for' grinding uniform rise cams comprising a" base; a spindle' mounted on said" base to rotatably-su-pport =a workpiece; said spin dle so mountedas to' permitlmovement of theworkpiece inthe* plane of rotation; a feed; car riage mountedon said bas'efor reciprocation nor-' mal to the" planecif'rdtatibri of said workpiece;

said carriage including? a generally cylindrical,-

annular grinding wlieel' and- 'means for driving" thesaine, oscillatory means to 'e'ifect reciproca'-' tion ofsaid carriageya' stroke carriage mounted on s'a'id basefor reciprocation in the plane paral lel=to theplane' of rotation of said-workpiece, said carriageincluding anadjhstabl rack and means for 'adjiisting-thesa me to a -sl'o'pi'ng position, oscillatory-mean's t'o efiect reciprocation of said'stroke carriage, a gear operatively'associated with saidspindle for effecting rotation thereof, said sloping rack" on saidstroke carriage engaging said gear for eife'ctingrota'tion and movement of said workpiece in its plane of rotation in accordance with said reciprocatingmovement,the combined rotational and planar" 'move'inents serving tocause the peripheral surface of the workpiece to progressively contact-- the surface"- of the grinding' wheel along "the contourof a uniform rise ria'ge mounted on said base for reciprocation normal to the plane of rotation of said workpiece, said carriage including a generally cylindrical, annular grinding wheel and means for driving the same, a crank operated oscillating lever to reciprocate said feed carriage, a stroke carriage mounted on said base for reciprocation in a plane parallel to the plane of rotation of said workpiece, said carriage including an adjustable rack and means for adjusting same to a sloping position, a crank operated oscillatin lever to effect reciprocation of said stroke carriage, a gear operatively associated with said spindle for effecting rotation thereof, said sloping rack on said stroke carriage engaging said gear for effecting rotation and movement of said workpiece in its plane of rotation in accordance with said reciprocating movement, the combined rotational and planar movements serving to cause the peripheral surface of the workpiece to progressively contact the surface of the grinding wheel along the contourof a uniform rise cam, and common driving means to drive said crank pins in such manner the oscillating levers will effect reciprocation of said. carriages in timed relationship.

, 5. A machinefor grinding uniform rise cams comprising a base, a spindle mounted on said base to rotatably support a workpiece, said spindle mounted in such manner as to permit movement of the workpiece in the plane of rotation, a feed carriage mounted on said base for ,reciprocation normal to the plane of rotation of said workpiece, said carriage including a generally cylindrical annular, grinding wheel, means for driving the same, and means for adjusting the grinding wheel into contact with the workpiece; an oscillating lever for reciprocating said feed carriage, a stroke carriage mounted on said base for reciprocation in aplane parallel to the plane of rotation of said workpiece, said carriage including an adjustable rack and means for adjusting the same to a sloping position, an oscillating lever to effect reciprocation of said stroke carriage, a gear secured to said spindle for effecting rotation thereof, said sloping rack on said stroke carriage engaging said gear for effecting rotation and movement ofsaid workpiece in its plane of rotation in accordance with said reciprocating movement, the combined rotational and planar movements serving to cause the peripheral surface of the workpiece to progressively contact the surface of the grinding'wheel along the contour of a uniform rise cam, andcommon driving means to oscillate said levers in such manner as to effect reciprocation of the carriages V in timed relationship. 7

6. A machine for grinding uniform rise cams comprising a base, a movable spindle mounted on" said base to rotatably supporta workpiece; said spindle permitting movement of the workpiece in the plane of rotation, a feed carriage mounted on said base for reciprocation normal to the plane of rotation of sa d workpiece, said carriage includina a generally cylindrical, annular grinding wheel and means for driving same, a stroke carrlage mounted on said base for'reciprocation in a plane parallel to the plane of rotation of said workpiece, said carriage including a table pivotallv mounted for adjustment into a sloping position and means for rigidly securing the same in adjusted position; a rack mounted on said table, a sine bar of the same height as the pitch.

line of said rack adjacently mounted on said t l a s s d o s id pindle fq tafisqties rotation thereof, a roll ofthe same diameter as serving to cause the peripheral surface of the workpiece to progressivel contact the annular surface of the grinding wheel along the contour of the uniform rise cam traced by a point on the pitch circle of said gear, and common driving means to effect reciprocation of said carriages in timed relationship.

'7. A machine for grinding uniform rise cams comprising a base, a spindle mounted on said base to rotatably support a workpiece, said spindle permitting movement of the workpiece in the plane of rotation, a feed carriage mounted on said base for reciprocation normal to the plane of rotation of said workpiece, said carriage including a generally cylindrical, annular grinding wheel and means for driving same, a stroke carriage mounted on said base for reciprocation in a plane parallel to the plane of rotation of said workpiece, a gear operatively associated with said spindle for effecting rotation thereof, a sloping rack on said stroke carriage of a length equal to the circumference of the pitch circle of said gear to engage said gear for eflecting' rotation and movement of said workpiece in the plane of rotation in accordance with said reciprocating movement, said workpiece rotating 360 as the rack reciprocates in one direction and being similarly reversibly rotated as said rack reciprocates in an opposite direction, said planar movement being sufficient to produce the desired rise on the cam, the combined rotational and planar movements serving to cause the peripheral surface of the workpiece to progressively contact the annular surface of the grinding wheel along the contour of a uniform rise cam, and common driving means to reciprocate said carriages in time relationship. 7

8. A machine for grinding uniform rise cams comprising a base, a spindle mounted on said base to rotatably support a workpiece, said spindle permitting movement of the workpiece in the plane of rotation, a feed carriage mountedon said base for reciprocation normal to the plane of rotation of said workpiece, said carriage ineluding a generally cylindrical, annular grinding wheel and means for driving same, a stroke carriage mounted on said base for reciprocation in a plane parallel to the plane of rotation of said workpiece, a gear operatively associated with said spindle for effecting rotation thereof, a sloping rack on said stroke carriage to engage said gear for effecting rotation and movement of said workpiece in the plane of rotation in accordance with said reciprocating movement, means operatively associated with said spindle to continuously urge said gear into engagement with said rack as the peripheral surface of said workpiece progressively contacts the annular surface ofsaid grinding wheel along the contour of a'uniform rise cam, and'common driving means to reciprocate said carriages in timed relationship. a 9. A machine for grinding uniform rise cams comprising a base, a spindle mounted on said base to rotatably support a workpiece, said spin,- dle permitting movement of the workpiece in the plane of rotation, a'feed carriage mounted on said base for reciprocation normal to the plane of rotation of said workpiece, said carriage including a generally cylindrical annular grinding wheel and means for driving the same, a stroke carriage mounted on said base for reciprocation in a plane parallel to the plane of rotation of said workpiece, a gear secured to said spindle for effecting rotation thereof, a sloping rack on said stroke carriage to engage said gear for effecting rotation and movement of said 10 workpiece in the plane of rotation in accordance with said reciprocating movement, a tension spring operatively associated with said spindle to continuously urge said gear into engagement with said rack as the peripheral surface of said workpiece progressively contacts the annular surface of said grinding wheel along the contour of a uniform rise cam, and common driving means to reciprocate said carriages in timed relationship.

JAMES MARTIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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