US2373640A - Cam lapping machine - Google Patents

Description

April 17, 1945; H. s. INDGE EI'AL CAM LAPPING MACHINE FiledJune 26, 1943 7 Sheets-Sheet 1 gwuc-w Tom A; .1 o G n 1 a g m 3 I H v in unun 7 M y u m,

U f M w .5 E H. H 5 HH H5 April 17, 1945. s; ||.\|DGE ETAL 2,373,640

CAM LAPPING MACHINE Filed June 26, 1943 7 Sheets-Sheet 2 HgHEEH T5 [ND 55 CHHRL E5 WL u/vu MMLD.WW

April 17, 1945. .N'D E ET AL 2,373,640

CAM LAPPING MACHINE Filed Jun 26, 1943 7Sheets-Sheet s I92 3mm HERBEHTE/NDEE EHHRLESWLL/ND fwmm w April 17, 1945." ETAL 2,373,640

' CAM'LAPPING MACHINE Filed June 26, 1943 7 Sheets-Sheet 4 HEl-T'EEE' 751N055 EHHHL. E5 \A/LL/ND Mwmi MW,

April 17, 1945. |NDGE ET AL 2,373,640

CAM LAPPING MACHINE Filed June 26, 1943 7 Sheets-Sheet 5 Mum W April l7, 1945- H. SJNDGE ETAL CAM LAPPING MACHINE 7 Sheets-Sheet 6 Filed Juhe 26, 1943 HEHEEF? T5 [ND 55 CHHRLESWL u/vu April 17, 1945.

Filed June 26, 1943 H. s. INDGE ET AL CAM LAPPING MACHINE HER 295/? T 5JND5E CHHE'L. E5 WL L/ND 7 Sheets-Sheet 7 Patented Apr. 17, 1945 7 Herbert S. Indge, Westboro, and Charles W. Lund, Boylston, Mass., assignors to Norton Company, Worcester, Mass, a corporation of Massachusetts Application June 26, 1943, Serial No. 492,436

-1arged scale, showin the arrangement of the 11 Claims.

This invention relates to abrading machines, and more particularly to a, cam lapping machine. One object of the invention is to provide a simple and thoroughly practical lapping machine forjsimultaneously lapping a plurality of cams.

A further object of' the invention is to provide an automatic cam lapping machine with a plurality of lapping arms each of which is arranged to lap. a cam. Another object of the invention is to provide a cam lapping machine with an automatically actuated abrasive paper feed which continuously presents a fresh abrading surface during a lapping operation.

A further object of the invention isto provide a cam lapping machine in which the lapping arm lapping arms, themaster cams and the cams to be lapped;

Fig. 5 is a fragmentary cross-sectional View,

' on an enlarged scale, taken approximately on the I line 5-5 of Fig. 1, showing the paper feeding N mechanism for the lapping arm and the lapping arm-reciprocating mechanism;

Fig. 6 is a similar fragmentary sectional view, on an enlarged scale, taken approximately on the line 66 of Fig. 1 showing the locking mechais controlled by a master cam positioned in axial alignment with and rotatable with the cam being lapped, thus eliminating the necessity for a synchronous, driving mechanism between the master cam and the cam to be lapped. Another object of th'e invention is to provide a cam lapping machine having movable cam lapping arms the movement of which is controlled by master cams mounted on an arbor supporting thecams to be lapped.

A further object of the invention is to provide a cam. lapping machine with a lapping arm assembly having a plurality of movable lapping arms supported thereon which is movable toward and from an operative position and which isarranged to be automatically clamped in an operative position during a lapping operation. A further object of the invention is to provide an automatically operated hydraulic clamping mechanism for looki the lapping arm assembly in an operative it 2| is provided with a rotatable work support comsition during a lapping operation. Other objects will bein 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

- the scope of the application of which will be inelectric wiring and control combined with the hydraulic actuating mechanism;

Fig. 4 is a fragmentary plan view, on an ennism forlocking the lapping arm assembly in an operative position;

Fig. 7 is a fragmentary plan view, on an en larged scale, of the forward ends of a pair of lapping arms;

' Fig. 8 is a fragmentary sectional view through the work supportin table showing the work loading cradle in end elevation;

Fig. 9 is a fragmentary front elevation, on an enlarged scale, of one of the work cradles;

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Fig. 10 is a fragmentary plan view, on an enlarged scale, of one set of the abrasive paper feeding'rollers; and Fig. 11 is'a fragmentary side elevation, on an enlarged scale, showing the adjustablethrow eccentric for actuating the abrasive lapping paper feed mechanism.

A pain lapping machine has been illustrated in the drawings comprisinga base Which supports a longitudinally reciprocable work supporting table 2|. Anti-friction type table Ways (Fig. 5') are provided between the base 20 and the table 2| to facilitate free reciprocatory movement of the table 2| relative to the base 20. Thetable prising a headstock 22 and a footstock 23. The headstock 22 is provided with a rotatable spindle 24 which is driven by anelectric motor 25. The motor 25 is equipped with a built-up speed reducing unit 26. A V-groove pulley 21 is provided on the speed reduction unit 26 which is connected by a multiple v belt 28 with a multiple V-groove pulley 29 which is mounted on the end of a rotatable worm shaft 30. The worm 30 in turn meshes'with a worm gear 3| which is fixedly supported on the headstock spindle 24. The headstock spindle 24 is provided-with a work driving head which is arranged to engage and drive the left-hand end of a work supporting arbor 36. The work supporting arbor 36 is arranged to sup-' port a plurality of cams 31 and 38 which are formed integral with an annular ring-shaped member 39. The member 39 is removably supported on a fixture 40 which is fixedly keyed to the work arbor 36.

In order to avoid the necessity of a synchronized drive between the cam being lapped and the master cam, it is preferable to provide a master cam supported on the work supporting arbor 35 which is of the same size and shape as the cam 5 to be lapped. The work arbor 35 is provided with a supporting plate 4! which is formed integral with a pair of master cams 42 and 43. The plate 4| together with the master cams 42 and 43 are identical with the cams previously described which are to be lapped. The plate 4| is in turn supported on a similar flanged member on the arbor 36 which is fixed relative thereto.

A similar plate 40a is mounted on the other end of the work arbor 36 and serves as a support for an annular ring shaped member 39a which has formed integrally therewith cams 31a and 38a to be lapped. A supporting flange 4! a is provided adjacent to the plate Mo on the work supporting arbor 36. The plate 45a serves as a support for 'a pair of master cams 42a and 43a which are identical in size and shape with the cams 31a and 38a to be lapped.

-The footstock 23 is provided with a rootstock center 44 which rotatably supports the right hand end of the work arbor 36. The footstock center 44 is supported in one end of a rotatable spindle 45 which is journalled in bearings (not shown) in a slidably mounted sleeve 46. The sleeve 46 is slidably keyed within a cylindrically shaped aperture formed within the footstock frame 23. The footstock center 44 is preferably moved to and from an operative position by a hydraulically operated mechanism comprising a cylinder 41 which contains a slidably mounted piston 48. The piston '48 is connected to one end of a piston 'rod 49. The other end of the piston rod 49 is pivotally connected to one end of a link '5!) (Fig. 3). The other end of the link 5|) is pivotally connected to one arm of a pivotally mounted bell crank lever 31 5|. The bell crank lever 5| is pivotally supported on a stud 52 and the other arm thereof is pivotallyconnected by means of a stud 53 with one end of a link 54. The other end of a link 54 is connected by a stud 55 with a slidably mounted sleeve 56 which is slidably supported within a cylindrical bore within the sleeve '46. A compression spring 51 is connected by a stud 55 with a slidably mounted sleeve 56 which is slidably supported within a cylindrical bore within the sleeve 46. A compression spring 5! is contained within the sleeve 56 and serves yieldably to maintain the footstock center 44 in an operative position when the bell crank lever 5| is swung to an operative position. 5

Lapping arm assembly It is desirable to provide a movable support for a plurality of lapping arms so that they may be simultaneously and quickly moved to and from 60 an operative position. A pair of spaced arms 62 and 63 are mounted on a rock shaft 64 (Fig. 2) which is supported in bearings on the rear of the machine base 20. The arms 62 and 63 are interconnected by a pair of spaced horizontally ex- 65 tending bars 65 and 66 which serve as slide ways for supporting lapping arm slides to be hereinafter described.

The lapping arm assembly supported by the arms 62 and 63 is arranged so that it may auto- 70 matically move to and from an operative position to facilitate loading of cams to be lapped into the machine and removing them therefrom after a lapping operation has been completed, In order v to move the entire lapping arm assembly to and 5 ten 96.

from an inoperative position, a fluid pressure mechanism is provided comprising a fluid pressure cylinder 68 which is pivotally connected by means of a stud 69 which is fixedly mounted within the base 20 of the machine. A piston H1 is slidably mounted within the cylinder 68 and is connected to one end of a piston rod H. The other end of piston rod .H is connected by a stud 12 with an arm 13. The arm T3 is pivotally supported on a stud 14 within the base 20. The other end of the arm 13 is connected by a stud 15 to one end of a link 16 which is in turn connected by a stud 11 with a toggle lever 18. The adjacent ends of the toggle lever 18 and a toggle lever 19 are connected by means of a stud 80. The toggle lever 18 is connected at its other end by means of a stud 19 which is fixedly supported within the base 29. The toggle lever 8| is connected by means of a stud 82 with an arm 83 which is fixedly mounted on the rock shaft 64 and is arranged to rock the shaft 64 together with the arms 62 and 63 and the entire lapping arm assembly either to or from an operative position.

The levers above described, as shown in full line position in Fig. 2, are in a position to hold the arm 83 together with the arms 62 and 63 and the entire lapping arm assembly in an operative position. When a lapping operation is completed fluid under pressure is admitted to a chamber in the lower end of the cylinder 68 to cause the piston 10 to move upwardly (Fig. 2) so that the piston rod ll moves toward the right to shift the levers T3, 16, I8, and 8| into the broken line positions, as indicated in Fig. 2 by the same numerals with the suffix a, so as to move the entire lapping arm assembly to an inoperative position.

A pair of slides and BI (Fig. 4) are slidably supported on the bars 65 and 66. The slide 90 serves as a support for a plurality of lapping arms 92, 92a, 92b, and 92c. The slide 9| serves as the support fora plurality of lapping arms 92d, 92e, 92f, and 92 (Fig. 4).

Lapping arm reciprocation It is desirable to impart a reciprocatory movement to the lapping arms during a lapping operation. A reciprocating mechanism is provided to simultaneously reciprocate the slides 96 and 9| in opposite directions so as to impart a relative reciprocatory movement between the lapping element and the cams to be lapped. A motor driven reciprocating mechanism is provided comprising an electric motor 95 which is supported on a pla- The platen 96 is fixedly supported on the rock shaft 64 and is arranged to move with the arms 62 and .63 to and from an operative position. The motor 95 is provided with a V-groove pulley 91 which is connected by a v-belt 98 with V-groove pulley 99 which is mounted on the rear end of a rotatable shaft N30. The shaft I00 is rotatably journalled in bearings NH and I02 which are carried by a bracket which is fixed relative to the bars 65 and 66 (Fig. 5). The shaft I00 supports a pair of eccentrics I03 (only one of which has been illustrated in Fig. 3 of the drawings) which are connected by connecting rods I04 and 05 with studs I06 and H11. Studs I06 and (01 are in turn supported by slides 90 and SI respectively. It will be readily apparent from the foregoing disclosure that when the motor 95 is set in motion, this motion will be transmitted through the mechanism above described simultaneously to reciprocate the slides 90 and 9'! in opposite directions.

Lapping arms and 32g are substantially identical in construction, consequently they have not all-been illustrated in detail. The lapping arm 92 (Fig. 6) comprises a transversely movable slide I I which is slidably mounted within a casing II I. The casing or frame III is provided with a dovetailed slide surface which mates with a correspondingly shaped dove-tailed way formed on the upper surface of the slide 90. It will'be readily apparent'from the construction as illustrated in Fig. 6 that each of the lapping arms may be independently adjusted longitudinally relative to the slides 90 and 9| respectively to" position the lapping arm in a desired and predetermined relationship with the master cams and cams to be lapped. A tension spring H3 is provided which is connected at one end by means of a stud II4 with the slide .-I I0. v The other end of the spring I I3 is connected by a stud I I5 with the frame I II. The tension of the spring II 3 normally serves to urge the slide I I0 in a forward direction so as to maintain the follower to be hereinafter described, in operative engagement with the face of the master cam during a lapping operation. The slide H0 is provided with. a yieldably mounted nose piece IIB which serves as a support for a continuous strip of abrasive lapping paper. 1

Abrasive paper-feed A. pair of upwardly extending brackets I I1 and II 8 are fixedly mounted on the upper portions of the arms 02 and 63 respectively, and serve as Lapping arms I 92, 92a, 92b, 92c, 92d, 92e, 92!;

a support for the abrasive lapping paper and the feeding mechanism therefor.

An independent roll of continuous flexible ab'-' rasive paper I20, I20a, I20b, I2llc, I20d, I2l le, I20,f, and I 20g is provided for each of the lapping arms.

and H8 respectively (Figs. 1 and 6) As,shown in Fig. 6, a strip of abrasive paper I22 from the roll of paper I20 passes downwardly are clamped at their other end to a shaft I29.

slidably mounted journalled blocks I30 and I'3I are provided for supporting the shaft I26.. These journals are slidably supported within the brackets I21 and I28 respectively. Adjusting screws I32 and I33 are provided on the brackets I21 and I 28 respectively by means of which the journal blocks I30 and I3I may be transversely adjusted to vary'the position of the feed roll I24 relative to the feed roll I23. The feed rollers I23 and I24 are geared together by means of a pair of meshing gears I34 and I35 which are fixedly mounted relative to the feed rollers I23 and I24 respectively. I

It is desirable that the abrasive lapping paper be automatically fed during thelapping operation so that a uniform abrading. surface is pro- The' rolls of abrasive paper are pivotally. supported on ashaft I2I which is in turn supported by the upwardly extending brackets Ill vided during the entire lapping operation. An automatic feeding mechanism is provided comprising a pivotally mounted arm I40 which is supported 'on the shaft I 26. An actuating pawl MI is pivotally' supported on the oscillatablearm I40. The arm I40fis oscillated by a mechanism to be hereinafter described. A pivotally mounted holding pawl I42 is supported by a bracket I43 which is fixedly supported on the shaft I25. This holding pawl I42 serves to prevent a counterclockwise rotation of the gear I35.

An electrically operated mechanism is provided for actuating. the feed pawl I4I. This mechanism.may comprise an electric motor I45 (Fig. 5) which is provided with an integrally formed built-in speed reduction unit I46. This motor driven gear reduction unitmay be of any of the. standard well known motor driven gear reduction units such as for example the Bodine reducerwhich is operatively connected to rotate a shaft I41. Shaft I41 is provided with an adjustably mounted eccentric I48. The eccentrio I48 is connected to a connecting rod I49 and a stud I50 with a downwardly extending arm I5I which is formedintegral with the oscillatable arm I40. It will be readily apparent from the foregoing disclosure that rotation of the motor I45 Will be transmitted to the gear reduction unit I46 to rotate the shaft I41 and the eccentric I48 .to transmit an oscillating movement through the connecting rod I40, to the arm I5I and the arm I40 continuously to oscillate the feed pawl MI. The feed pawl I4I rides idly over the teeth on the gear I35 when the arm I40 is moved in a counterclockwise direction. When the arm I40 is moved in a clockwise direction, the feed pawl I4I engaging the teeth of the gear I35 rotates the gear in a clockwise direction (Figs. 5 and 6) to impart a feeding movement to the abrasive lapping paper.

, After passing through the feed rolls I23 and J24 the worn out lapping paper is rolled up on a-reel I 52 which is supported on a shaft I53 (Figs. 5- and 6). A ratchet wheel I54 is provided on the reel I52. A holding pawl I55 serves to prevent rotation. of the reel I52 in a clockwise direction.

A feed pawl I56 is .pivotally mounted at the right hand end of a link I51 (Figs. 5 and 6). The other end ofthe link I51 is connected by a stud I58 with the upper end of, the arm I40. A tension spring I59 serves normally to hold the ratchet pawl I55 in the position illustrated in Figs. 5 and'6. The tension ofthe spring I59 is preferably sufficient to transmit the desired motion to the reel I52 so that the slack worn out abrasive paper is wound up after which any further motion of the arm I40 will cause the feed pawl I56 to ride idly over the ratchet wheel I54.

Similar abrasive lapping paper feed rollers together with the automatic feeding mechanism' therefor are provided for'each of the lapping arms 92, 92a, 92b,.92c, 92d, 92e, 92f, 92g. These feed rollers and wind up rollers are all actuated in the same manner by. independent pawl and ratchet mechanisms all of which are actuated and driven by the electric motor I45. Only one of these mechanisms has been illustrated in detail as ,above described. Any one of the feed mechanisms may be rendered inoperative as de-' sired by throwing the feed and wind up pawls to an inoperative position.

As illustrated in Fig. 4 the work arbor 36 is arranged to lap a pair of cams 31 and 38 at one end of .the arbor and a pair of cams 31a and 38alocated at the other end of the arbor. During this lapping operation the lapping arms 92b, 92c, 92d, 92's, are inoperative. A second arbor (not shown) may be provided which may be loaded, whil arbor 36' is being lapped with cams positioned in operative relationship with the lapping arms 92b, 92c, 92d, and 92e for the second lapping operation. It will thus be seen that the lapping arms as provided are utilized only on every other lapping operation in the setup illustrated in the drawings. This arrangement is due primarily to the design of the cam to be lapped and the manner in which they must be mounted and located on the arbor for the lapping operation.

The nose piece I I6 (Fig. '1) is adjustably mounted on the left hand. side face of the lapping arm 92 and is arranged so thatit may be adjusted vertically and horizontally relative thereto. The lapping arm 92 is provided with an off set bracket I60 which serves as a support for a master camroller I6I which engages peripheral surface of the master cam 42. -It will be readily apparent from the foregoing disclosure that motion of the master cam 42 which is mounted on the work arbor 36 will be transmitted through the bracket I60 to impart a controlled transverse movement tothe lapping arm 92 so as to impart a corresponding movement to the nose piece IIG which supports the abrasive lapping paper I22.

The lapping arm 92a is provided with an off set nose piece I I6a which is connected by a bracket 162 with the forward end of the lapping arm 92a. A bracket IE3 is adjustably supported on the side face of the lapping arm 92a and serves as a support for a master cam roller I64. The bracket I63 is adjustably supported on the lapping arm 92a. so that it may be adjusted vertically and also horizontally relative thereto to facilitate timing the master cam follower with the action of the nose piece II6a during lapping operation. It will be readily apparent from the foregoing disclosure that the motion of the master cam 43 will be imparted through the roller I64' and the bracket I63 to the lapping arm 92a which in turn transmits a corresponding movement through the bracket I62 to the nose piece I I Get to control the lapping action on the cam 38.

Each of the pairs of lapping arms 92b, 92c, 92d, 92c, 92 and 92g are similarly provided with offset nose pieces and master cam rollers which are designated by th same numerals sufilxed with the'letters b, c, d, e, f and g. These arrangements are identical with that just described in connection with the lapping armsv 92 and 92a, consequently it is deemed unnecessary to describe these several units in detail.

In order to overcome the thrust of the master cams and product cams against the lapping arm assembly during a lapping operation, it is desirable to provide a suitable clamping mechanism for clamping the lapping arm assembly in an operative position. In the preferred form, a hydraulically operated clamping mechanism is provided for clamping each of the arms 62 and 63 in an operative position' The clamping mechanism comprises a pair of. spaced cylinders I10 and I'll which contain pistons I12 and I13 respectively. The pistons I12 and I13 are fixedly connected to piston rods I14 and I15 respectively (Fig. 3). The cylinder I10 is preferably pivotally supported by a stud I16 which is in turn fixedly supported relative to the base 20 (Fig. 6). The other end ofthe piston rod I14 is pivotally connected by a stud I11 with the upper end of a pivotally mounted clamping member I18. The

clamping member I19.is. pivotally supported by a stud I19 which is fixed relative to the base 20 (Fig- 6). A link I80, is pivotally supported by a stud I8I on the arm 63. The lower end of the link I is provided with a cylindrically shaped member I9I whichis arranged to mate with a correspondingly shaped surface I82 formed on a bracket I83, when the lapping arm assembly is in an operative position (Fig. 6) v The clamping device associated with the arm 62 and cylinder I1I is, identical in construction to that'just described, consequently it has not been illustrated and described in detail.

After the lapping arm assembly is moved to an operative position fluid under pressure is admitted through a, pipe I85 automatically to move the pistons I12 and I13 to actuate bothof the clamping members I18 (only one of which has been illustrated in Fig. 6) to clamp the lapping arm assembly rigidly in an operative position relative to the base 20.

Hydraulic controls A hydraulically operated control mechanism is provided for actuating and controlling th various elements of the machine. A motor driven fluid pressure pump I is'provided for drawing fluid through a pipe I9I from a reservoir I92 and passing fluid under pressure through a pipe I93 to a start and stop valve I94 (Fig. 3). A relief valve I95 is provided to facilitate passing exhaust fluid under pressure from the system directly to the reservoir I92. .The valve I95 is a standard adjustable pressure relief valve and consequently has not been illustrated in detail. The start and stop valve I 94 is a piston type'valve comprising a valve stem I96 having a plurality of valve pistons formed integrally therewith. In the position of the valve I94 (Fig. 3) fluid under pressure passing through the pipe I93 passes outwardly through a pipe I9-1 into an end chamber I98 in a piston type control valve I99. The valve I99 comprises a valvestem-200 having a plurality of valve pistons formedintegrally therewith. An end chamber 20I of the valve I99 is connected by a pipe 202 with the start and stop valve I94 and as shown in Fig. 3 is connected so as to exhaust fluid from the chamber 20I through a passage 203 and a pipe 204 into the reservoir I92. It will be readily apparent from the foregoing disclosure that the start and stop valve I94 serves to control the admission of fluid under pressure to and from the end chambers I98 and 20I of the control valve I99 to shift the valve stem 200 either toward the right (Fig.3) into the position illustrated in the drawings, at the end of the lapping cycle, or to shift the valve stem 200 toward the left to initiate a lapping cycle. An adjustable valve 205 is provided in the pipe line 204 to facilitate controlling the exhaust of fluid from the end chambers I98 and 20I of the control valve I99 so as to control the-rate of movement of the valve stem 200 when it is moved in either direction.

The control valve I99 is \operatively connected to control the admission of fluid under pressure to the cylinder 68 to cause a movement ofthe lappin arm assembly to and from an operative position, to the cylinder 41 to actuate the footstock center, and also to the cylinders I10 and HI to actuate the clamping mechanism to clamp the lappng arm assembly in an operative position.

The control valve I99 is provided with valve chambers 206, 201, and 208. The valve chamber 206 is connected by pipe 209 with a chamber 2I0 formed in the upper end of the cylinder 68; The

stem 200 to move toward the left (Fig. 3) at the same time'the normally open limit switch 242 is closed. During the initial shifting movement of the valve stem 200, fluid is admitted through the pipe 2 into the cylinder chamber 2 I5 to actuate the footstock center 45 and move in into an operative position in supporting engagement withthe work supporting arbor-36 after which fiuid under pressure is admitted to the cylinder chamber 2H1 of the cylinder -68 to cause a movement of the lapping arm assembly toward an operative position. During the movement of the lapping arm assembly, the switch 243 is closed. The switch 243 is connected in series with-the limit switch 242 so that when'both of these'switches areclosed, the circuit is completed and the electric'starter switch 260 operates to start the headstock motor 25 and at the same time sets the time relay 260 in motion to energize the starter switch 253 and start the motor'95 to reciprocate the'lappi-ng arms during a lapping operation.

The magnetic starter switch 253 is actuated to start the electricalmotor I45 which in turn serves in a manner above described to'continuously feed abrasive paper during a lapping operation. The electrical motor I 45 is connected with the time relay 260 so that after a predetermined. initial lapping operation has taken place, the relay 260 operates to stop the motor 95 to stop the lapping arm reciprocation and also to stop the motor I45 so as to stop the continuous feed of the abrasive lapping paper for a final lapping operation.

Operation The operation of this improved lapping machine will be' readily apparent from the foregoing disclosure. Two sets of work pieces to be lapped are clamped in position on the'work supporting arbor 36 which is placed in a rotating position on a pair of spaced work arbor supporting cradles after which the work arbor 24 is rolled into position with its axis in alignment with the'axis of the headstock spindle 24' and the footstoc'k'center 45. The motor driven fiuid pump I90 is then set 'in' motion. 'When it'is desired to start a lapping cycle, the "control lever 230 is shifted manually in a counterclockwise direction (Figs. 1 and 3) to shift thestart and stop valve I94 to a starting or downward position which admits fluid under pressure through the pipe I91 to cause the control'valve I99 to move toward the left to initiate a lapping cycle. The shifting of the control valve I99 'towardthe left serves first to admit fluid through the pipe 2I4 to actuate the footstock center 45 so as to move it into operative supporting engagement with the work arbor 36 after which fluid is admitted through the pipe 299 to the cylinder 68 to move the lapping arm assembly to an operative position. Continued movement of the valve I99 toward the left serves to admit fluid under pressure through the pipe I85 automatically to actuate the clamping mechanism to clamp the lapping arm assembly in an operative position.

The movement of the control lever 230 to a starting position serves to close the normally open limit switch 242 and the movement of the lapping arm assembly serves to close the normally open limit switch 243 which closes a series circuit to start the work drive motor 25 and at the same time sets the time relay 260 in motion and to start the motor 95 to impart a reciprocating movement to the pair of slides 90 and El. This movement imparts a simultaneous reciprocatory movement in opposite directions to the slides 90 and BI, so as to impart a relative reciprocating movement to the lapping arms. At the same time the motor 95 is started, the motor M5 is started to impart a continuous feeding movement to the abrasive lapping paper. The lapping operation proceeds for a predetermined time interval as governed by the time relay 260. After a predetermined time interval has elapsed, the relay 26D serves to simultaneously stop the motors 95 and I 45 thus stopping. the reciprocation of the lapping arms and at the same time stopping the continuous feed of the abrasive lapping paper after a predetermined initial lapping has been completed. The lapping operation continues for a final 0r finish lapping operation. When the relay 260 is actuated after the initial lapping operation has been completed, it serves to set in motion the second time delay relay 26I which governs the extent of the final or finish lapping operation. After a predetermined final or finish lapping operation during which time the abrasive lapping paper is held stationary and the lappingarms are not reciprocated, the time relay 26l operates to energize the solenoid 231 to shift the control lever 23!! in a counterclockwise direction into the position illustrated in Fig. 3 to initiate a movement of the electric and hydraulic controls. The start and stop valve I94 is moved upwardly into the position shown in Fig. 3 which serves to admit fluid under pressure through pipe I91 into the end chamber I98 so as to move the valve stem 200 toward the right into the position illustrated in Fig. 3 during which time fluid under pressure is admitted through the pipe I86 to release the hydraulic clamping mechanism after which the lapping arm assembly is moved to an inoperative position. Movement of the lapping arm assembly to an inoperative position serves to open the limit switch 243 as previously described. The fluid under pressure is then admitted to the footstock cylinder chamber 2I'I to withdraw the footstock center 45, and the work arbor 36 may then be removed from the machine and the next work arbor placed in position for the necessary lapping operation.

It will be readily apparent from the foregoing disclosure that the predetermined or initial lapping operation may be automatically controlled by the setting of the time relay 260 and the duration of the final or finish lapping operation may be readily controlled by manipulation of the time relay 26I, thus providing a readily controlled automatic cycle of operation, it being only necessary for the operator to initiate the cycle by shifting the main control lever 230 in a counterclockwise direction.

It will thus be seen that there has been provided 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 invention and as many changes might be made in the embodiment above set forth, it is to be understood that all mattershereinabove set forth or shown in the accompanying disclosure are to be interpreted as illustrative and not in a limiting sense.

We claim: 7

1. In a cam lapping machine having a base, a rotatable work support including a headstock and a footstock, a work arbor supported by said headstock and footstock for supporting a cam to be lapped, a movably mounted support on said base, a slidably mounted cam lappingarm on said support, a lapping element on said arm, a

rotatable follower roller on said arm, and a masimpart a contrOlled'sliding movement to said lapping" arm and said element to maintain said lapping element continuously in lappingengagement with the face of saidcam during a lapping operation.

2. In 'a cam lapping machine having a rotatable work support including a headstock and a footstock, a work arbor supportedthereby for supporting a cam to be lapped, a slidable cam lapping arm, a yieldably mounted nose piece on said arm, a lapping element including a con-- tinuous strip of abrasive paper on said arm, a rotatable follower roller on said arm, and a master cam supported on said work arbor adjacent to said cam to be lapped to impart a controlled sliding movement to said arm during a lapping operation.

3. In a cam lapping machine having a base, a rotatable work support forsupporting and rotating a cam to be lapped, a movable support on said base, a movable cam lappingarm on said support having a lapping element, a follower on said arm, a master cam for controlling the movement of said follower and arm, means to move said support to and from an operative position, and independent means-to clamp said support in an operative position during a lapping operation.

4. In a cam lapping machine having a base, a rotatable work support for supporting and rotating a cam to be lapped, a movable support on said base, a slidably mounted cam lapping arm on saidsupport, a lapping element on said arm, a follower on said arm, a master cam to impart a controlled movement to said arm during a lapping operation, means including a piston and cylinder to move said support and lapping arm to and. from an operative position, and means including a fluid pressure actuated clamp t clamp said support in an operative position.

5. In a cam lapping machine having a base, a rotatable work support for supporting and rotating a cam to be lapped, a pivotally mounted frame supported on said base, a slidably mounted'lapping arm on ,said frame, a lapping element on said arm, a follower on said arm, a master cam which is arranged to impart a controlled movement to said arm during a lapping operation,

means to swing said frame to and from an operative position, and independent, means to clamp said frame in an operative position relative to said base during a lapping operation.

6. In a cam lapping machine having a base, a rotatable work support for supporting and rotating a cam to be lapped, a pivotally mounted frame ton and cylinder to move said frame and'lapping arm-to and from an operative position, a piston and: cylinder actuated clamping mechanism to lock said frame in an operative position during a lapping operation, and a control valvewhich is arranged successively to admitfluid to said cylinder for moving said frame and thereafter to said clamp actuating cylinder.

8. In a cam lapping machine having a base, a rotatable work support including a headstock and footstock for rotatably supporting a plurality of cams to be lapped, a pivotally mounted frame, a plurality of slidably mounted lapping arms on said frame, a lapping element on each of said arms, a follower on each of said arms, a master cam to impart a controlled movement through said follower to said arm, a clamping mechanism to clamp the frame in an operative position, means including a piston and cylinder to actuate said footstock, means including a piston and cylinder to move said frame and lapping arms to and from an operative position, and-means including a piston and cylinder to actuate said clamp,

9. In a cam lapping machine having a base, a rotatable work support including a headstock and footstock for rotatably supporting a. plurality of cams to be lapped, a pivotally mounted frame, a plurality of slidably mounted lapping arms on said frame, a lapping element on each of said arms, a follower on each of said arms, a master cam-to impart a controlled movement through said follower to said arm, a clamping mechanism to clamp the frame in an operative position,

means including a piston and cylinder to actuate said footstock, means including a piston and cylinder to move said frame and lapping arms to and from an operative position, means including a piston and cylinder to actuate said clamp, and acontrol valve which is arranged successively to admit fluid under pressure to said footstock cylon said base, a slidably mounted lapping arm on said frame, a lapping element on said arm, a follower on said arm, a master cam to impart a controlled movement through said follower to said arm during a lapping operation, means including a piston and cylinder to swing said frame to and from an operative position, and means including a piston and cylinder actuated clamp to lock said frame in an operative position during a lapping operation.

7. In a cam lappingma'chine having abase, a rotatable work supportfor supporting and rotating a cam to be lapped, a pivotally mounted frame, a slidably mounted lapping arm on said frame, a lapping element on said arm, a follower on said arm, a master cam to impart a controlled movement through said follower to said arm during a lapping operation, means including a pisinder, said frame cylinder, and said clamping cylinder.

10. In a cam lapping machine having a base, a rotatable work support including a headstock and footstock for rotatably supporting a plurality of cams tobe lapped, a pivotally mounted frame, a plurality of slidably mounted lapping arms on said frame, a lapping element on each of said arms, a follower on each of said arms, a master cam to impart a controlled movement through said follower to said arm, a clamping mechanism.

to clamp the frame in an operative position, means including a piston and cylinder to actuate said footstock, means including a piston and cylinder to move said frame and lapping arms to and from an operative position, means including a piston and cylinder to actuate said clamp, a control valve which is arranged successively to admit fluid under pressure to said footstock cylinder, said frame cylinder, and said clamping cylinder, and a manually operated start and stop valve to control the actuation of said control valve to initiate a lapp n operation.

11. In a cam lapping machine having a base, a rotatable work support including a headstock and footstock for rotatably supporting a plurality of cams to be lapped, a pivotally mounted frame, a plurality of slidably mounted lapping arms on said frame, a lapping element on each of said arms, a follower on each of .said arms, a master cam to impart a controlled movement through said follower to said arm, a clamping mechanism to clamp the frame in an operative position, means including a piston and cylinder to actuate admission of fluid to the'end chambers in said V control valve, manually operable means to shift said start and stop valve to initiate a lapping cycle, and an automatically actuated mechanism to shift said start and stop valve after a predetermined lapping operation has been completed to terminate the lapping cycle.

HERBERT S. INDGE. CHARLES W. LUND.

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