US2109386A

US2109386A - Cam grinding apparatus

Info

Publication number: US2109386A
Application number: US175100A
Authority: US
Inventors: Clarence J Green
Original assignee: Norton Co
Current assignee: Saint Gobain Abrasives Inc
Priority date: 1937-11-17
Filing date: 1937-11-17
Publication date: 1938-02-22
Anticipated expiration: 1955-02-22

Description

Feb. 22, 1938. R EN 2,109,386

. CAM GRINDING APPARATUS Original Filed Jan. 23, 1936 2 Sheets-Sheet 2 gwumviom ELF/RENEE J. GREEN Straw,

ing the master cam roller.

Patented F eb. 22, 1938 CAM GRINnmG APPARATUS Clarence J. Green, Worcester, Mass, assignor to Norton Company, Worcester, Mass, at corpo ration of Massachusetts Continuation of application Serial Nos. 60,477:

and 60,478, January 23, 1936.

This application November 17, 1937, Serial No. 175,100

23 Claims.

matically indexing the master cam roller relative to the master cam.

Another object of the invention is to provide a fluid pressure actuated mechanism for index A further object of the invention is to provide an electrically actuated mechanism for indexing the master cam roller. Other objects will be in 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 indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a fragmentary front elevation of a cam grinding machine which is partly diagrammatic to show the operation of the mechanism;

Fig. 2 is a fragmentary sectional View, taken approximately on the line 2-2 of Fig. 1, showing the arrangement of the rock bar, master cam and roller and mounting for the grinding wheel;

Fig. 3 is a sectional view, on an enlarged scale,

taken approximately on the line 33 of Fig. l;

Fig. 4 is a fragmentary cross sectional view, taken approximately on the line 44 of Fig. 3; and

Fig. 5 is a fragmentary front elevation of a modification of the cam grinding apparatus shown in Fig. 1.

A camshaft grinding machine has been illustrated in the drawings of the type shown in the prior patent to Trefethen and Belden No. 1,783,- 755, dated December 2, 1930. This machine comprises a base It which supports a transversely movable wheel slide II. The wheel slide ll carries a rotatable wheel spindle [2 which supports The wheel I3 and wheel slide II are arranged for a transverse feeding movement relative to the base. A feeding mechanism has been illustrated comprising a half nut 20 depending from-the wheel slide l l and meshing with or engaging a rotatable feed screw 2| which, is rotatably supported in bearings (not shown) inrthe base ID. The feed screw 2| isprovided with a forwardly extending shaft fl having a manually operable feed wheel 23mounted on its outer end. By rotation of the feed wheel 23,-.the screw 2! may be rotated to'cause a forward orrearward feeding movement of the grinding wheel I3. In order positively to stop the forward feeding movement of the grinding wheel when it reaches a predetermined position, an' abutment -25 is adjustably mounted on the feed wheel Hand is arranged to engage a stop pawl 26 which is pivotally supported on a stud 21 mounted on the base H]. A micrometer adjusting mechanism 28 is carried by the feed wheel 23 and is arranged precisely to adjust the position of the abutment 25 relative to the feed wheel 23. The micrometer adjusting mechanism 28 has not been illustrated in the present case since it is notconsidered to be part of the present invention. This adjustment is substantially identical to the adjustment shown and described in detail in the expired U. S. Patent to Norton No. 762,838, dated June 14, 1904.

A longitudinally .movabletable 30 is arranged to slide longitudinally on .a fiat way 3! and a V- way 32 which mate with'correspondingly shaped ways on the base IQ of the machine. The table 30 is arranged to support a pivotallymounted rock bar 35 which is provided with trunnions 36 and 3! at opposite ends thereof. The

trunnions

36 and 31 are supported in

bearings

38 and 39, respectively, which arefixed on theupper surface ,of the table 39. The rock bar 35 is provided with a headstock center 40 and a footstock center 4| which serverotatably to support a camshaft 42 to be ground. A driving dog 43 is mounted on the end of the camshaft 42 and is arranged to be driven by a driving plate 44 carried spindle 45 serves as a support for a plurality of master cams 46 which are arranged to be engaged by arotatable master cam roller 41. The master cam roller 41 is rotatably supported by brackets which are fixed to the table 39 so that when the master cams 46 are rotated in engagement with the rotatable master cam follower 41, a rocking motion will be transmitted to the rock bar 35 so as to oscillate the camshaft 42 toward and from the operative face of the grinding wheel I3 so as to generate a predetermined contour on the cam being ground.

The headstock spindle 45 may be rotated in the manner shown in the prior patent to Trefethen et al. No. 1,783,755, to which reference may be had for details of disclosure.

A fluid pressure cylinder 60 is fixedly supported by the table 30 and is provided with a piston BI.

having a piston rod 62 engaging a projecting arm '63 of the rock bar 35. A spring 64 within the lower chamber of the cylinder 60 surrounds the piston rod 62 and is interposed between the piston 6| and a cylinder head 65 and serves to rock the rock bar 35 in a counterclockwise direction, as indicated in Fig. 2, so as to maintain the master cam 46 in operative relation with the master cam roller 41.

The table 35 may be traversed longitudinally to index the camshaft 40 so as to position successive cam blanks to be ground in operative relation with the grinding wheel I3 either manually or by power. For the sake of simplicity of illustration, a manually operable traverse mechanism has been illustrated in the drawings comprising a manually operable traverse wheel I0 which is mounted on a rotatable shaft II, the inner end of which supports a gear I2. The gear 'I2"meshes with a large gear I3 mounted on a rotatable shaft '14. The shaft I4 carries a gear I5 mounted on its inner end which meshes with a rack bar 76 depending from the table 30.

After a cam on the shaft 42 has been ground to a predetermined size and contour, it is desirable to index the table 30 longitudinally to present a new cam blank in operative relation with the grinding wheel I3. After a cam blank has been ground to size, it is first necessary to turn the feed wheel 23 in a clockwise direction to separate the wheel I3 from the cam blank being ground. This rearward movement of the wheel serves to admit fluid under pressure through a pipe 35 into a cylinder chamber 67 so as to rock the rock bar 35 in a clockwise direction, as illustrated in Fig. 2, to separate the master cams 45 from the roller 47 and to separate the camshaft 42 -from the grinding wheel I3. Details of the mechanism for admitting fluid through the pipe 66 have not been illustrated in the present case, since this is not considered part of the present invention. For details of disclosure of this feature, reference may be had to the prior patent to Trefethen and Belden No. 1,783,755. dated December 2, 1930.

In order to attain the main object of the present invention, namely to provide an automatic indexing mechanism for the master cam roller 41, it is desirable to provide a suitable mechanism which operates in timed relationship with the table movement, so that when the table is indexed to present a new cam blank into operative relation with the grinding wheel I3, the master cam roller 41 will automatically index into operative position with relation to the master cam corresponding to the cam blank to be ground. In the preferred construction, a fluid pressure mechanism is provided for automatically indexing the master cam roller longitudinally in timed relationship with the relative traversing movement between the grinding wheel and the camshaft being ground.

The master cam roller 41 is slidable longitudinally on a rotatable shaft 80 which issupported in bearings (not shown). A yoke 8I straddles the master cam roller 41 and is arranged to move the roller longitudinally to index the same into operative relation with successive master cams 45. The yoke 8| is carried by a slidably mounted rack bar 82 which is arranged to be indexed longitudinally by means of a fluid pressure mechanism to be hereinafter described which operates in timed relation With the longitudinal indexing movement of the work table 30.

A valve 83 is mounted on the base of the machine and is arranged to control the admission of fluid to cause the desired indexing movement. The valve 83 is preferably of the balanced piston type, comprising valve pistons 84 and 85 which are formed integral with a valve stem 86. The valve stem 86 is provided with a pin 81 which rides. in an elongatedslot 88 in a control lever 89. The control lever 89 is pivotally mounted on a stud 90 on the base I0 and its upper end is arranged in the path of a plurality of adjustable dogs 9| which are adjustably supported in a T-slot 92 in the table 30. One end of a spring 93 is attached to a stud 94 on the lower end of the lever 89 and the other end is attached to a stud 95 on the base I0 of the machine. The spring 93 serves to hold the lever normally in a vertical or neutral position so that the valve pistons 84 and 85 are in the position illustrated in Fig. 1.

Fluid under pressure is supplied from any suitable source, such as a pump (not shown) within the base of the machine which forces fluid under pressure through a pipe 96 into a valve chamber 91 between the valve pistons 84 and 85. Assuming the table 30 to be traveling in the direction of the arrow, as shown in Fig. l, by means of rotation of the traverse wheel I0, this motion continues until the second dog 9| strikes the upper end of the lever 89 and rocks the lever in a clockwise direction which causes the valve stem 86 to move toward the left, as viewed in Fig. 1, so as to uncover a pipe 98 and admit fluid under pressure from the valve chamber 91 through the pipe 98 into a cylinder chamber 99 within a fluid pressure cylinder I00. The cylinder I00contains a slidably mounted piston IIII having a piston rod I02, the outer end of which is formed as a rack bar I03 which meshes with a gear I04. The gear I04 is rotatably mounted on a shaft I 05. In order that the rotary motion of the gear I04 may transmit an intermittent motion to the rack bar 82,- a ratchet pawl I01 is mounted on the gear I04. The ratchet pawl I01 is arranged to cooperate with a ratchet wheel I08 formed integral with a sleeve I09 which is rotatably supported on the shaft I05. The other end of the sleeve I09 is provided with a gear IIO which meshes with the rack bar 82. 30 is moved manually, as above described, it admits fluid under pressure to the cylinder chamber 99 and moves the piston IOI toward the right, as viewed in Fig. 1, causing the rack bar I03- to rotate the gear I04 in a counterclockwise direction. This motion serves through the pawl IN to rotate the ratchet wheel I08, the sleeve I09, and the gear H0 in a counterclockwise direction to cause the rack bar 82 to move toward the left, as viewed in Fig. 1, so as to index the master cam roller 42 into operative engagement with the next master cam.

In order to limit the indexing motion of the master cam roller so that the roller moves only to a sufiicient distance to bring it into operative relation with the next master cam, an adjustable stop screw I I5 is provided in the right-hand end of the cylinder I00 to limit the movement of the piston IOI so as to cause the desired index- When the table v ing movement. When thetable 30 has been traversed to a predetermined extent, the dog 9| passes over the end of the lever 89, releasing the tension of the spring 93 which serves again to move the valve stem 86 toward the right, as viewed in Fig. 1, to return the valve pistons 84 and to the positions illustrated in Fig. 1. This movement allows the fluid within the cylinder chamber 99 to exhaust through pipe 98, into valve chamber I it and out through a pipe I|'I into the reservoir. A spring ||8 surrounds the piston rod H32 and is interposed between the piston I 0| and the right-hand cylinder head so that when the fluid pressure is cut off from the pipe 98, the released tension ofthe spring H8 serves to aid in quickly exhausting fluid from the cylinder chamber 99. This movement causes the rack bar I03 to move toward the left, as viewed in Fig. 1, causing a clockwise movement of the gear I04, and due to the arrangement of the ratchet pawl I01 causes the pawl to ride idly over the teeth of the ratchet wheel I38 so that it is ready for the next indexing movement.

When the table 30 is moved toward the left, as viewed in Fig. 1, the dogs 9| striking the upper end of the lever 89 serve to rock the lever in a counterclockwise direction, moving the valve stem 88 toward the right, as viewed in- Fig. 1, so that the valve pistons 84 and 85 move toward the right and uncover a pipe I20 so that fluid under pressure passing from the pipe 95 into the valve chamber 91 passes through pipe I20 into a cylinder chamber |2I within a cylinder |22. The cylinder I22 is provided with a piston I23 having a piston rod I24 the outer end of which is formed as a rack bar I25 meshing with a gear I28 and rotatably supported on a shaft I27. The gear i 26 carries a pivotally mounted ratchet pawl I28 which is arrangedto engage a ratchet wheel (not shown) which corresponds with the ratchet wheel I08. The ratchet Wheel is carried by a sleeve which is rotatably supported'on the shaft |2I. The sleeve carries a gear I29 meshing with the rack bar I28. When fluid under pressure is admitted to the cylinder chamberIZI, it causes the piston I23 and piston rod I24 to'move toward the left, as viewed in Fig. 1, causing a corresponding movement to the rack bar I25 to rotate the gear I26 in a clockwise direction (Fig. 1)

which serves through the ratchet pawl I28 to cause the gear I29 to be rotated in a clockwise direction to move the rack bar 82 toward the right, as viewed in Fig. 1, so as to index the master cam roller into operative relation with successive master cams when the table is being indexed toward the left, as viewed in Fig. 1.

An adjustable stop screw I30 is provided in the left-hand end of the cylinder I22 which serves to limit the movement of the piston I23 toward the left and thereby adjustably limit the extent of indexing movement transmitted to the master cam follower roller 41. A spring |3| surrounds the piston rod I24 and is interposed between the piston I 23 and the cylinder head to aid in exhausting fluid from the cylinder chamber I 2| when the reverse or control valve stem 85 moves into a neutral position, as illustrated in Fig. 1, exhausting fluid through a valve chamber I32 and through a pipe I33 into the reservoir. During the return movement of the piston I23 toward the right, as viewed in Fig. 1, the rack bar causes the gear I28 to move in a coonterclockwise direction and the ratchet pawl I28 rides idly over the teeth of the ratchet wheel so that the parts are in position for the next indexing movement of the table. V V

An electrically actuated master cam roller shifting or indexing mechanism has been illustrated in the modification shown in Fig. 5. Many of the parts shown in the modification (Fig. 5) are identical with the corresponding parts shown in Figs. 1 to 4 inclusive and consequently have been indicated by the same reference numerals. An electrical switch 83a. is mounted on the front of the machine base and is arranged to control an electrical apparatus for causing an indexing movement of the master cam roller 41. The switch 83a is preferably a single pole, double throw knife switch comprising a pair of contact members 84a and 85a. The movable part of the switch 83a comprises a knife arm 86a which is pivotally mounted on a stud 90a on the base I0. Suitable insulation is provided for the parts of the switch, which is common' practice in the art. A spring 93 is inter' posed between the lower end of the arm 86a and the insulated stud 95 on the base of the machine which serves normally to hold the knife arm 80a in an open or central position- The upper part 89a of the arm 86a is arranged in the path of a plurality of adjustable dogs 9| which are adjustably supported in a T-slot 92 on the front edge of the table 30. Electrical energy is supplied from any suitable source of power and in the present case has been indicated by the power leads 96a and 91a. The power line 91a is connected to theknife arm 86a. 7

7 Assuming the table 30 to be traveling in the direction of the arrow (Fig. 5), by means of rotation of the manually operable. traverse wheel 10, the traversing movement continues until the second dog 9| strikes the upper end of the lever 89a and rocks the lever in a clockwise direction which swings the knife arm 86a so as to engage the contact member 840., as indicated in dotted lines in Fig. 1, thereby closing a circuit to energize a solenoid mm which causes the rod |0Ia to move toward the right, as viewed in Fig. 1, against the tension of a spring |'|8a. One end of the rod |0|a is formed as a rack bar|03a mesh-r viewed in Fig. 1, it causes the gear I04 to move in a counterclockwise direction, and as the ratchet pawl I01 engages the teeth of the ratchet Whel I08, causes the gear 0 to rotate in a.

counterclockwise direction to move the rack bar 82 in a direction toward the left, as viewed in Fig. 5, to index the master cam roller 41 toward the left into operative relation with the next master cam 48.

In order adjustably to limit the extent of the indexing movement, an adjusting screw MM is mounted on the frame of the machine and is arranged in the path of a downwardly projecting lug I I Ia carried by the rack bar l03a so that the extent of movement of the rack bar |03a toward the right (Fig. 5) may be readily adjusted to index the master cam roller to a predetermined ex-' the fullline position, (Fig. 5), thereby breaking the circuit and deenergizing the; solenoid IBM.-

indexed toward the left (Fig. 5), the lever 89a.

is moved in a counterclockwise. direction so that when a dog 9| strikes the lever 89a, it serves to rock the knife arm, 86a into engagement with the contact member'85aso as to energize a solenoid I22aand cause a rod I23a to move toward the left (Fig. 5). The left-hand end of the rod I23a is formed as a rack bar I25a meshing with a gear. I26. The gear I26 carries a ratchet pawl I28.which is arranged to cooperate with a ratchet wheel similar to the ratchet wheel I08 shown in Figs..3 and 4.. The gear I26 is rotatably supported ona shaft I21. The shaft I21 also supports a gear I29rwhich meshes with the rack bar 82. When the solenoid I22a is energized, the rod I23a and rack bar I25a are moved toward the left (Fig. 5) against the tension of a spring I24a to causethe gear. I26 to move in a clockwise direction so that the pawl I28 will rotate the ratchet. wheel and the gear I29 in a clockwise direction to cause the rack bar. 82 to move toward the right, as viewed in Fig. 5, tov index the master camroller toward the right on successive longitudinal indexing movements of the table 30 into operative relation with successive master cams. An adjusting screw I3Ba is provided to limit the movement of, the rack bar I25a and cooperates with a. lug; I31 a; depending. from the rack bar l25a. so that the extent of indexing movement of the rack bar 82 may be readily adjusted.

The operation of this machine is readily apparent from the foregoing disclosure. The camshaft 42 to be ground is mounted in position on the headstock center 49 and the footstock center 4| and the master cams 46 and camshaft 42 are rotated. The table 30 is'then traversed longitudinally by means of the manually operable traverse wheel ID to position the first cam in operative relation with the. grinding wheel l3. The feed wheel23 is then rotated in a counterclockwise direction (Fig. 1) to cause an infeeding movement of the grinding wheel to grind the cam blank to the required size and contour while the camshaft 42 and its supporting rock bar 35 are rocked toward and from the grinding wheel I3 by means of the master cams 46 and the rotatable master cam roller 41, After the .first'cam blank has been ground, the feed wheel 23 is turned ina clockwise direction to separate the grinding wheel from the cam blank being ground. Thismovement serves also toadmit fluid under pressure to the cylinder chamber 67 to rock the rock bar 35. to. an inoperative position, in accordance with the disclosure in the Trefethen et al. Patent No. 1,783,755. The table 30 is then traversed longitudinally by rotation of the traverse wheel 'IILto position the next cam blank into operative relation with the grinding wheel I3. During this traversing movement of the table 38, a dog; 9I strikes the upper end of the lever 89 and shifts the valve stem 86 either toward. the right or toward the left, depending on the direction of traverse, which admits fluid under pressure either through the pipe 98 or I20 into either the cylinder chamber 99'or I2I to cause a longitudinal indexing movement of the raokbar, 82.

and-the master cam roller 41 to positio-nthe master cam roller 41 in operative relation with the next master cam corresponding with the cam blank to be ground. This cycle of operation is repeated until all of the cams on a camshaft have been ground to a predetermined contour and size.

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 matter hereinbefore set' forth as shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

This case is a continuation of my prior copending U. S. applications Serial No. 60,477 and Serial No. 60,478 both. of which were filed on January 23, 1936.

I claim:-

1. A cam grinding machine having a longitudinally movable table, means to traverse said table, a rotatable master camshaft, a cam follower movable longitudinally relative to said shaft, means for shifting said follower comprising a fluid pressure piston and cylinder, and means to control the admission offluid to said cylinder.

2. A cam grinding machine having a longitudinally movable table, means to traverse said table, a rotatable master camshaft, a cam follower movable longitudinally relative to said shaft, means for shifting said follower comprising a fluid pressure piston and cylinder, and a fluid pressure system including a control valve which is actuated by movement of said table whereby the follower is moved in timed relationshipwith the table movement.

3. A cam grinding machine having a longitudinally movable table, means to traverse said table, a rotatable master camshaft, a cam follower movable longitudinally relative to said shaft, means to move said; follower comprising a fluid pressure piston and cylinder, a rack and gear mechanism interposed between the piston and the follower, and a fluid pressure system including a control valve, and means including adjustablevdogs on said table to actuate said valve so as to index the cam follower automatically in timed, relation with the table movement.

4. A cam grinding apparatus comprising a longitudinally movable table, means to traverse said table longitudinally, a pivotally mounted camshaft support on said table, a master camshaft aligned with said camshaft'support, a master cam follower roller movable in a path longitudinally relative to the axis of said shaft, a gear mechanism for moving the follower, a fluid pressure piston and cylinder mechanism to actuate said gear mechanism, anda fluid pressure system including a control valve which is actuated in timed relation with the table movement automatically to index the master cam roller.

5. A. cam grinding apparatus comprising a longitudinally movable table, means to traverse said table, a pivotally mounted camshaft support on said table, a master camshaft aligned with said camshaft support, a master cam follower roller movable in a path longitudinally relative to the axis of said shaft, means including a rack and, gear mechanism for moving the follower, a fluidpressure piston andcylinder mechanismto actuate said gear mechanism, and a fluid pressure system including a control valve which is actuated in timed relation with the table movement automatically to index the master cam roller in timed relationship with the table movement so that the master cam roller is automatically positioned in operative relation with the master cam corresponding to the cam being ground.

6. A cam grinding apparatus comprising a longitudinally movable table, a rock bar pivotally mounted on said table, a camshaft support on said rock bar, a master camshaft arranged in axial alignment with said camshaft support, a plurality of master cams carried by said shaft, a movable master cam follower roller cooperating with said cams, means including a rack and gear mechanism to index the master cam roller, a

' fluid pressure piston and cylinder operatively connected to actuate said rack and gear mechanism to index the master cam roller in one direction, a second rack and gear mechanism arranged to move said follower in the opposite direction, a second fluid pressure piston and cylinder operatively connected to actuate said rack and gear mechanism to index the master cam roller in the opposite direction, and a' control valve which is actuated in timed relation with the table movement automatically toindex the master cam roller in either direction in timed relation with the table movement.

7. A cam grinding apparatus of the type having a longitudinally movable table, means to traverse the table longitudinally, a rock bar pivotally mounted on said table, a camshaft support on said rock bar, a master camshaft rotatably mounted on said rock bar and arranged in axial alignment with the camshaft support, a master cam follower roller movable in a path parallel to the axis of said master camshaft, a rack and gear mechanism arranged to shift the follower in either direction, a fluid pressure mechanism including a piston and cylinder to actuate said rack and gear mechanism to index the master cam roller in either direction, a plurality of adjustable dogs on said table, and a control valve actuated by said dogs to control the admission of fluid to said piston and cylinder automatically to index the master cam roller in either direction in timed relationship with the table movement.

8. A cam grinding apparatus of the type having a longitudinally movable table, a rock bar pivotally mounted on said table, a rotatable camshaft support on said rock bar, a master camshaft rotatably supported on said rock bar and arranged in axial alignment with the camshaft support, a plurality of master cams supported on said shaft, a master cam follower roller cooperating with said master cams and movable in a path parallel to the axis of said master camshaft, means including a rack and gear mechanism to index the follower roller in either direction comprising a fluid pressure piston and cylinder, a pawl and ratchet mechanism actuated by said piston and cylinder to rotate the gear mechanism to index the master cam roller in one direction, and a control valve actuated in timed relation with the table movemnt to admit fluid under pressure automatically to index the master cam roller.

9. A cam grinding apparatus of the type having a longitudinally movable table, a pivotally mounted rock bar on said table, a rotatable camshaft support thereon, a master camshaft rotatably supported thereon and arranged in axial alignment with the camshaft support,ra master cam follower roller which is movable in a path parallel to the axis of the master camshaft,

means to index said follower roller comprising a rack and gear mechanism, a pawl and ratchet mechanism arranged to turn said gear mechanism, a fluid pressure piston and cylinder operatively connected to actuate said pawl and ratchet mechanism to index the master cam roller in one direction, and a control valve actuated intimed relation with the table movement to control the admission of fluid to said cylinder to index the master cam roller automatically in timed relationship with the table movement.

10. A'cam grinding apparatus of the'type having a longitudinally movablework table, a pivotally mounted rock bar on said table, a rotatable camshaft support on said rock bar, a rotatable master camshaft arranged in axial alignment with said camshaft support, a rotatable master cam follower roller movable in a path parallel to the axis of the master camshaft, means including a rack and gear mechanism to move said follower roller, a fluid pressure actuated pawl and ratchet mechanism to actuate said gear and rack mechanism to move the follower roller in one direction, a second fluid pressure actuated pawl and ratchet mechanismwhich is operatively connected to said rack and gear mechanism so as to move the follower roller in the opposite direction, and afluid pressure control Valve to control the admission of fluid to both of said fluid pressure actuated mechanisms automatically to index the master cam roller in timed relation with the table movement.

11. A cam grinding apparatus of the type having a longitudinally movable work table, a pivotally mounted rock bar on said table, a rotatable camshaft support on said rock bar, a rotatable master camshaft arranged in axial alignment withsaid camshaft support, a rotatable master cam follower roller movable in a path parallel to the axis of the master camshaft, means including a rack and gear mechanism tomove said follower roller, a fluid pressure actuated pawl and ratchet mechanism to actuate said gear and rack mechanism to move the follower roller in one direction, a second fluid pressure actuated pawl and ratchet mechanism which is operatively connected to said rack and gear mechanism so as to move the follower roller in the opposite direction, and a fluid pressure control valve actuated in timed relation with the table movement to control the admission of fluid to both of said fluid pressure actuated mechanisms automatically to index the master cam roller in timed relation with the table movement.

12. A cam grinding machine having a longitudinally movable table, a rotatable master camshaft thereon, a cam follower movable longitudinally relative to said shaft, means including a rack and gear mechanism to move said follower, means to actuate said rack and gear mechanism, a control mechanism to actuate said means, and means including adjustable dogs on said table to actuate said control mechanism so as to index the cam follower automatically in timed relation with the longitudinal movement of the table.

13. A cam grinding apparatus comprising a longitudinally movable table, a rock bar pivotally mounted on said table, a camshaft supported on said rock bar, a master camshaft arranged in axial alignment with said camshaft support, a plurality of master cams carried by saidshaft, a movable master cam follower roller cooperating With said cams, means including a rack and gear mechanism to index the master cam roller, actuating means operatively connected to operate said rack and gear mechanism to index the master cam roller in one direction, a second rack and gear mechanism arranged to move the follower in the opposite direction, a second actuating mechanism operatively connected to actuate said second rack and gear mechanism to index the master cam roller in the opposite direction, and means including a control device which is actuated in timed relation with the table movement automatically to index the master cam roller in either direction in timed relation with the table movement.

14. A cam grinding apparatus of the type having a longitudinally movable table, a rock bar pivotally mounted on said table, a rotatable camshaft support on said rock bar, a master camshaft rotatably supported on said rock bar and arranged in axial alignment with the camshaft support, a plurality of master cams supported on said shaft, a master cam follower roller coopcrating with the master cam and movable in a path parallel to the axis of the master camshaft, means including a rack and gear mechanism to index the follower roller in either direction, means including a pawl and ratchet mechanism to actuate said rack and gear mechanism to index the master cam roller in one direction, and a control device actuated in timed relation with the table movement to control said solenoid automatically to index the master cam roller,

15. A cam grinding apparatus of the type having a longitudinally movable: table, a pivotally mounted rock bar on said table, a rotatable camshaft support thereon, a master camshaft rotatably supported thereon and arranged in axial alignment with the camshaft support, a master cam follower roller which is movable in a path parallel to the axis of the master camshaft, means to index the follower roller comprising a rack and gear mechanism, a pawl and ratchet mechanism arranged to turn said gear mechanism, means operatively connected to actuate said pawl and ratchet mechanism to index the master cam roller, and a control device actuated in timed relation with the table movement t'o-control said pawl actuating means so as to indexthe master cam roller automatically in timed relation with the table movement.

16. A cam grinding apparatus of the type having a longitudinally movable table, a pivotally mounted rock bar on said table, a rotatable camshaft support on said rock ban-a rotatable master camshaft arranged in axial alignment with said camshaft support, a rotatable master cam follower roller movable in a path parallel to the axis of the master camshaft, means including a rack and gear mechanism to move the follower roller, a pawl and ratchet mechanism -to actuate said rack and gear mechanism to ,move the follower roller in one direction, a second pawl and ratchet mechanism to actuate said rack and gear mechanism to move the follower roller in the opposite direction,.and-a control mechanism actuated in timed relation with the table movement to control and actuate both of said pawl and ratchet mechanisms automatically to index the master cam roller in either direction in timed relation with the table movement.

1'7. A cam grinding apparatus comprising a longitudinally movable table, a pivotally mounted camshaft support on said table, a master camshaft aligned with said camshaft support, a master cam follower roller movable in a path longitudinallyrelative to the axis'ofsaid shaft, a gear mechanism to move said follower, a solenoid to actuate said gear mechanism, and an electrical circuit including a control switch which is actuated in timed relation with the table movement automatically to index the master cam roller.

18. A cam grinding apparatus comprising a longitudinally movable table, a pivotally mounted camshaft support on said table, a master camshaft aligned with said camshaft support, a master cam follower roller movable in a path longitudinally relative to the axis of said shaft, means including a rack and gear-mechanism for moving the follower, an electrical apparatus including a solenoid to actuate said rack and gear mechanism, and an electrical circuit including a control switch which is actuated in timed relation with the table movement'automatically to indexthe master cam roller in timed relationship with the table movement so that the master cam roller is automatically positioned in operative relation with the master cam corresponding to the cam being ground.

19. A cam grinding apparatus comprising a longitudinally movable table, a rock bar pivotally mounted on said table, a camshaft support on said rock bar, a master camshaft arranged in axial alignment with said camshaft support, a plurality of master cams carried by said shaft, a movable master cam follower roller cooperating with said cams, means including a rack and gear mechanism to index the master cam roller, electrical apparatus including a solenoid operatively connected to actuate said rack and gear mechanism to index the master cam roller in one direction, a second rack and gear mechanism arranged to move said follower in the opposite direction, a second solenoid operatively connected to actuate said second rack and gear mechanism to index the master cam roller in the opposite direction, and an electrical circuit including a vcontrol switch which is actuated in timed relation with the table movement automatically to .index the master cam roller in either direction lin timed relation with the table movement.

20. A cam grinding apparatus of the type having a longitudinally movable table, a rock bar pivotally'mounted on said table, a camshaft support on said rock bar, a master camshaft rotat- 1 ably mounted on said rock bar and arranged in axial alignment with the camshaft support, a master cam follower roller movable in a path parallel to the axis of said master camshaft, a rack and gear mechanism arranged to follower in either direction, electrical mechanism including a solenoid to actuate said rack and gear mechanism to index the master cam roller in either direction, a plurality of adjustable dogs on said table, and a control switch actuated by said dogsto control the electrical circuit automatically to index the master cam roller in either direction in timed relationship with the table movement.

21. A cam grinding apparatus of the type havshift the i anism to index the follower roller in either direction comprising an electric solenoid, a pawl and ratchet mechanism actuated by the solenoid to actuate the rack and gear mechanism to index the master cam roller in one direction, and a control switch actuated in timed relation with the table movement to control said solenoid automatically to index the master cam roller.

22. A cam grinding apparatus of the type having a longitudinally movable table, a pivotally mounted rock bar on said table, a rotatable camshaft support thereon, a master camshaft rotatably supported thereon and arranged in axial alignment with the camshaft support, a master cam follower roller which is movable in a path parallel to the axis of the master camshaft, means to index the follower roller comprising a rack and gear mechanism, a pawl and ratchet mechanism arranged to turn said gear mechanism, an electrical solenoid operatively connected to actuate said pawl and ratchet mechanism to index the master cam roller in one direction, and a control switch actuated in timed relationship with the table movement to control said solenoid to index the master cam roller automatable master camshaft arranged in axial alignment with said camshaft support, a rotatable master cam follower roller movable in apath parallel to the axis of the master camshaft, means including a rack and gear mechanism to move the follower roller, an electrically actuated pawl and ratchet mechanism to actuate said gear and rack mechanism to move the follower roller 7 in one direction, a second electrically actuated pawl and ratchet mechanism which is operatively connected to said rack and gear mechanism so as to move the follower roller in the opposite direction, and an electrical control switch actuated in timed relation with the table movement to control both of said electrically actuated pawl and ratchet mechanisms automatically to index the master cam roller in timed relation with the table movement.

CLARENCE J. GREEN.