US2078462A - Cam grinding machine - Google Patents

Description

April 27, 1937. I A SILVEN 2,078,462

CAM GRINDING MACHINE Filed March 27, 1935 5 Sheets-Sheet l April 27,1937.

H. A. SILVEN CAM GRINDING MACHINE Filed March 27, 1935 5 Sheets-Sheet 2 H/ITNESSES April 27, 1937.

H. A. SILVEN CAM GRINDING MACHINE Filed March 27, 1935 5 Sheets-Sheet 3 April 27, 1937. H A s v N 2,078,462

CAM GRINDING MACHINE Filed March 27, 1955 5 Sheets-Sheet 4 WGgqxfiM: j

27, 1937. H. A. SILVEN CAM GRINDING MACHINE Filed March 27, 1935 5 Sheets-Sheet 5 HER ERT AlkS/L VEN W/ TNES 6 E6 i atented Apr; 27,

UNITED STATES PATENT OFFICE 2,078,462 AM GRINDING MACHINE tion of Massachusetts Application March 27, 1935, Serial No. 13,289

19 Claims.

This invention relates to grinding machines,

and more particularly to an improvement in cam grinding apparatus.

Heretofore, in the grinding of camshafts, it has ,5 been found necessary to grind the cam while feeding the wheel into the work and then allowing the grinding wheel to remain in operative engagement with the work during a finish grinding or dyingout period in order that the cam may be finished to the required size. The die-out period, if the wheel is allowed toentirely grind out, requires considerable time and results in impairing the eificiency of the grinding machine. Attempts have been made to eliminate the die-out period or to reduce it to a minimum, but such a grinding operation without a die-out cut results in a reentrant curve being produced on the periphery of the cam due to the curvature of the wheel at the point where the wheel and the cam separate from r each other after grinding. While the reentrant curve is, in many cases, not wholly detrimental to the action of the cam, it does, however, leave :a distinct mark on the cam and is of sufficient rconsequence to cause the rejection of a camshaft at the automobile plants in mass production, since the cam must be finished, according to the automotive specifications, to a surface having a predetermined contour and finish.

It has been found by experimentation that if 30 the cam being ground and the grinding wheel can be separated when the nose of the cam is in con- .tact with the wheel, the reentrant curve produced 'will be substantially eliminated. It has been the practice in manually controlled machines to attempt to manually separate the cam from the wheel or vice versa when in the above-mentioned predetermined position, that is, when the high point or nose of the cam is in operative engage- :ment with the periphery of the grinding wheel. 40 Such a manual operation, however, requires a highly skilled operator and necessitates a loss of time in grinding cams due to the fact that the operator must reduce the cam to the required size :and then separate the cam and the wheel when the cam is in the desired position.

It is the primary object of this invention to provide an automatic lifting device which serves to automatically separate the work being ground :from the grinding wheel when a predetermined 50 portion of the work periphery is in contact with the wheel.

' It is another object of this invention to provide an automatic nose lifting device which serves to automatically separate the cam being ground v55 from the grinding wheel when a predetermined portion of the cam, such as the nose or the high point of the cam, is in contact with the wheel.

It is a further object of this invention to provide an electro-hydraulic mechanism for automatically separating the cam and the grinding wheel when the nose of the cam is in operative engagement with the wheel. Other objects will be apparent from the foregoing disclosure.

One embodiment of this invention has been illustrated in the drawings, in which like reference numerals indicate like parts:

Fig. l is a fragmentary perspective view of a cam grinding machine embodying this invention;

Fig. 2 is a fragmentary end elevation, on an enlarged scale, of the improved cam grinding machine having parts broken away and shown in section to more clearly show the operation of the mechanism; Y

Fig. 3 is a fragmentary end view, on an enlarged scale, of the nose lifting control device;

Fig. 4 is a fragmentary sectional view, on an enlarged scale, taken approximately on the line 4-4 of Fig. 2;

Fig. 5 is a fragmentary plan view partly in section, on a reduced scale, taken approximately on the line 5+5 of Fig. 4;

Fig. 6 is a fragmentary rear elevation of the nose lifting control switch and its operating parts;

Fig. 7 is a fragmentary top plan view of the parts shown in Fig. 6;

Fig. 8 is a vertical section through the rock bar actuating cylinder; and

Fig. 9 is a perspective view, on an enlarged scale, of the nose lifting control switch and its operating parts.

Broadly, this invention comprises a machine for grinding successive cams on an integral camshaft, such as are used in the modern automobile, in which the grinding wheel and the camshaft are moved transversely relative to each other to grind the cam blank to a predetermined size and contour and in which the grinding wheel and camshaft are moved longitudinally relative to each other to position successive cams in operative relation with the grinding wheel. This machine is provided with an automatically actuated mechanism for separating the cam blank and grinding wheel only When a predetermined portion of the cam, namely, the nose or high point of the cam, is in operative contact with the periphery of the grinding wheel when the cam has been ground to a predetermined shape andsize.

Grinding wheel feed A grinding machine embodying this invention has been illustrated in the drawings, in which a base supports a transversely movable wheel slide ll mounted on the V-way l2 and flat way (not shown). The wheel slide ll carries a rotatable grinding wheel l3. The grinding wheel slide ll may be moved transversely relative to the base It by any suitable mechanism, such as a rotatable cross feed screw [5, which is supported in bearings (not shown) in the base. A half nut l5 depending from wheel slide H engages the threaded portion of feed screw l5. A reduced projection ll of the feed screw [5 carries a gear 48 meshing with a pinion l9 on a shaft which in turn supports a manually rotatable feed wheel 2|. The feed wheel 2| is provided with an adjustable abutment 22 arranged to enage a stop pawl 23 which is pivotally mounted by means of a stud 24 on the base Ill. The feed wheel 2! is provided with the usual micrometer adjusting mechanism 25 which serves to adjust the abutment 22 relative to the feed wheel 2| so as to precisely adjust the stopping point of the infeeding movement of the grinding wheel to permit accurately sizing the work piece being ground. This feed mechanism is substantially the same as that shown in the prior U. S. Norton Patent No. 762,838 dated June 14, 1904 and the U. S. patent to Trefethen et al. No. 1,783,755 dated November 2, 1930, to which reference may be had for further details of disclosure not shown in the present drawings.

Longitudinal table traverse A longitudinally movable table is slidably mounted on the usual fiat way 3| and V-way 32 and is arranged to be moved longitudinally relative to base it. The table 30 may be traversed longitudinally either manually or automatically, as desired, but for the sake of simplicity of illustration, a manual operable traverse mechanism has been illustrated comprising a rack bar 33 depending from the under side of table 30. The rack bar 33 meshes with a gear 34 mounted on a rotatable shaft 35 which is rotatably supported in the base Ill. The outer end of the shaft 35 carries a manually operable traverse wheel 36 which may be rotated in either direction to traverse table 30 relative to base I0 and grinding wheel I 3.

Rock bar and master cams In order that a cam may be accurately ground to a predetermined contour, it is necessary to provide a secondary transverse movement between the wheel and cam blank during the grinding operation in order that the desired contour may be produced on the cam. This movement may be accomplished by imparting a relative transverse movement between the wheel and cam blank but for the sake of simplicity of illustration, the conventional type of cam grinding apparatus has been illustrated, comprising a rock bar which is pivotally supported on the table 55 by means of brackets 4! so that the bar 40 is free to rock about its axis 42. The rock bar 40 carries at one end a headstock portion 43 which rotatably supports a master camshaft having a plurality of master cams 44. The rock bar also supports a product camshaft 45, having a plurality of cams 46 formed integrally therewith, in axial alignment with master cams 44. The master cams and product shaft are supported in the well-known manner employed in camshaft grinding machines, such as, for example, as shown in the patent to Trefethen et al. No.

1,783,755 dated December 2, 1930. Since the mountings of the master cams and the product camshaft do not constitute an essential part of the present invention, only an indication of this support has been made in the present case. For further details of mounting of these parts, reference may be had to the prior patent to Trefethen et al.

In order that a relative transverse movement may be provided to produce the predetermined contour on the cam 46 being ground, it is desirable to rock the bar with a predetermined controlled movement so that the desired relative motion may be produced between the grinding wheel and the cam being ground to produce a predetermined contour on the cam. A master cam follower roller 48 is slidably keyed to and supported on a rotatable shaft 49 which is journaled in brackets 50 and 5| on a headstock frame 52 which is fixed to-the table 30.

The master camshaft may be driven by any suitable means, such as a pulley 53 (Fig. 1) which is driven by a belt 54 from an overhead source of power or, if desired, a motor driven unit may be provided by replacing the pulley 53 with an electric motor. The pulley 53 is mounted on the outer end of a shaft 55 which is journaled in a bracket 56 fixedly mounted on table 30. The shaft 55 is connected by a flexible or universal joint 5? to rotate a shaft 58 which is in turn connected by a flexible or universal joint 59 with the master camshaft carrying the master cams 44. By rotation of the pulley 53, a rotary motion is transmitted to the master cams 44 and also to the product camshaft 45 which, due to the mounting and arrangement of the parts, serves to cause a rocking of the rock bar 40 as the master cams 44 rotate to cause a predetermined transverse movement between the cam being ground and the operative face of the grinding wheel so as to generate a predetermined contour on the cam.

Rock bar-pressure device In order that the master cams 44 may be maintained in operative engagement with the follower roller 48 during the normal grinding operation, a yieldable means is provided to exert a pressure on the rock bar and maintain the master cams 44 in the desired contact with the roller 48. As illustrated in the drawings, a lever arm 6! (Fig. 2) is rigidly fixed to rock bar 40. A connecting rod 62 is pivotally connected by a stud 63 on lever B I. The upper end of rod 63 is provided with a collar 64 which is freely slidable within a cylinder casing 55 which is supported on headstock frame 52 by means of a bracket 66. A spring 61 surrounds the rod 62 and is contained within the cylinder 65. The spring 6'! is interposed between the movable collar 64 and a collar 68 which is fixed to the lower end of cylinder 65 so that the compression of spring 67 tends to move the arm 6! and rock bar 40 in a counterclockwise direction, as viewed in Figsrl and 2, so as to maintain the master earns 44 in operative engagement with the master cam roller 48 during the normal grinding operation.

Rock bar-automatic separation It is desirable to provide a suitable automatically actuated mechanism to rock the bar 45 in a clockwise direction so as to separate the master cams 44 from the roller 48 and also to separate the cams 45 from the grinding wheel I3. This is preferably accomplished by a fluid pressure operated mechanism, such as that shown in the prior patent to Trefethen, et al. No. 1,783,755 dated December 2, 1930, to which reference may be had for details of disclosure not found in the present application. The fluid pressure mechanism may comprise a pump HI (Fig. 1) within the base II] which is adapted to draw fluid from a reservoir (not shown) through a pipe II, a pipe 12 and a pipe 13 to a control valve 14. A rack bar I5, formed on the projecting end of the stem of control valve I4 and meshing with a gear '88 on a shaft 11, is operatively connected through a lost motion friction device I8 with a gear i9 which meshes with the feed screw gear I8 so that when the feed wheel 2| is turned to cause a reverse or rearward feed of the wheel, the gearing and friction device cause the rack 15 to move toward the ,"right, as viewed in Fig. 1, shifting valve pistons 80 and BI also toward the right so as to allow fluid under pressure to pass from pipe I3 through a valve chamber 98 into a pipe 82. The pipe 82 is in turn operatively connected to a control valve 83 which is mounted on the side of a fluid pressure cylinder 84. The cylinder 84 is supported on the headstock bracket 52. A piston 85 is slidably mounted within the cylinder 84 and serves to move a piston rod 86 which buts against the outer end of the lever BI. When fluid under pressure is admitted through pipe 82, valve 83, it passes through a passage 81 into a cylinder chamber 88 to cause a downward movement of piston 85, rod 86, so as to rock the lever 6! and rock bar 40 in a clockwise direction to separate the master cams 44 from the roller 48 and the camshaft 45 from the grinding wheel I3. The valve pistons and ports of valve 83 are so arranged that in any position of valve 83, there is a free passage for fluid between the pipe 82, passage 81 and cylinder chamber 88. When the grinding operation is started, the rotation of feed wheel 2I, to cause an infeed, serves to shift valve 14 towards the left so that the pistons 80 and 8I are in the full line position (Fig. 1). This movement serves to out 01f fluid pressure and opens a passage 89 to allow fluid to exhaust from the cylinder chamber 88 through passage 81, valve 83, a pipe 82, a passage 89, through valve chamber 90 and out through a pipe 9| into the reservoir, thus allowing free exhaust of fluid. The clockwise rocking of the bar 48 and lever 6| into an inoperative position is limited by an adjustable stop screw 93 carried by a bracket 94 which is fixed to the headstock frame 52. The above described mechanism serves to rock the bar 40 to an inoperative position when the wheel feed is operated to cause a rearward movement of the grinding wheel and also to return the rock bar 40 to an operative position when the wheel feed mechanism is rotated to cause an infeeding of the grinding wheel.

Nose lifting device In order to attain the main object of this invention, it is desirable to provide a mechanism, such as is hereinafter termed a nose-lifting device, for automatically separating the product earns 46 from the grinding wheel I3, only when the cam is in a predetermined rotative position, such as when the nose or high point of the cam is in operative contact with the wheel. To accomplish this result, a mechanism is provided which is preferably operated automatically in timed relation with the rocking of the bar 40. While a master cam 44 is rotating through one complete turn, the bar rocks toward and from the work once as controlled by the shape of the master cam. By utilizing the rocking of the bar, it is possible to automatically cause a separation of the master cam 44 and the follower roller 48 as well as the product cam 46 and the grinding wheel I3 when the high point of the master cam is in engagement with the surface of the master cam roller and the high point of the product cam 46 is in engagement with the grinding wheel.

The valve 83 is provided with a valve stem Ill and valve pistons H8, H9 and I20. The valve 83 is preferably automatically actuated, such as by means of a solenoid I2I which is connected by 'a bell crank lever I22 pivotally mounted on a stud I23 to move valve 83 in one direction, and a spring I24 is connected to move valve 83 in the opposite direction. When the solenoid I2I is energized, the bell crank I22 is moved in a counterclockwise direction (Fig. to shift the valve stem II'I toward the right (Fig. 5). This movement serves to allow fluid under pressure from pump 18 to pass through a pipe 95 and the valve 83 through a passage 96 into a cylinder chamber I25 to cause a downward movement of a piston I26 so as to rock the lever 6| into position 6m and also to rock bar 40 in a clockwise direction to separate the product cam from the grinding wheel. The piston rod 86 is preferably formed in two parts which are loosely connected by a telescopic connection I21 which permits independent operation of pistons 85 and I26. The piston I26 is operated first by means of an electric control device hereinafter described to rock the lever 8| from the full line position (Fig. 2) into broken line position GIa after the cam has been ground to a predetermined extent and when the nose or high point of the cam is in operative engagement with the grinding Wheel. The piston 85, which is connected through rod 86, is actuated when the wheel feed is reversed to move the grinding wheel to an inoperative position and serves to cause a further downward movement of piston rod 86 to move lever 6| from the broken line position Gla into position BIZ) and to rock bar 48 into an inoperative position. When the bar 48 is in an inoperative position, the master cams and follower roller are sufficiently separated to permit indexing of the master cam follower roller relative to the master cams and indexing of the camshaft being ground relative to the operative face of the grinding wheel.

Nose lifting device-electric control In order that the valve may be actuated in the proper timed relation with the cam being ground, an electrically operated device is provided to energize solenoid I2I when a predetermined portion of the master cam, namely, the high point or nose of the cam, is in operative contact with the grinding wheel. Such a mechanism may comprise a mercury tube switch I30 which is secured in clips I3I on a rotatable plate I32. The plate I32 is preferably made of an insulating material. The plate I32 is adjustably carried by a ratchet wheel I33 which is in turn mounted on the outer end of a rotatable stud I34. The stud I34 is supported in an aperture I35 in a bracket I36 which is fixed to the table 38. A sleeve I31 is fixedly connected with the ratchet plate I33 and adapted to be rotated therewith.

A rotatable pawl carrying plate I38 is rotatably supported on a sleeve I31. The plate I38 carries a pawl E39 which is pivoted on a stud I40 and is arranged to be held in engagement with the teeth, of the ratchet wheel by means of a spring Mil interposed between the end of the pawl I39 and a portion of the plate I38. A projection I 42 of plate -38 is arranged in the pathof a lug I43 which is fixedly mounted to the rock bar 45 so that when the rock bar is rocked to carry the work piece toward and from the grinding wheel to generate the predetermined contour on the cam blank, the lug Hi3 engaging the projection M2 rocks between full line position (Fig. 3) and position i lia which serves to actuate the pawl plate, 538 and the ratchet, pawl i353 to cause an intermittent rotary motion of the ratchet wheel 33. It will be readily apparent that the intermittent rotation of the ratchet wheel I33 in a counterclockwise direction (Fig. 3) serves to tip the mercury switch I36, in a counterclockwise direction, through a sufficient distance so: that a column of mercury I44 joins with a column of mercury IMa, to close the circuit between terminals I 41 and I 48. The closing of the circuit serves to energize the solenoid I2! and thereby shift the valve 33 to admit fluid under pressure into cylinder chamber I25 to rock the bar 45 in a clockwise direction so as to remove the cam from operative engagement with the grinding wheel when a predetermined portion of the cam, namely, the nose or high point of the cam, is in operative engagement with the wheel. A safety pawl I45 is pivotally mounted on a stud I45 which is in turn supported on a non-rotatable plate I47. The pawl I45 is maintained in operative engagement with the ratchet wheel 533 by means of a spring N58. The plate it? is held stationary by a pin I49 so that the pawl I 35, therefore, serves as a safety pawl to prevent the ratchet wheel 5 33 from turning in a clockwise direction during its normal movement.

The ratchet plate 133 which supports the mercury switch ltil is provided with. a projecting lug 255 which is connected by a spring I5! with a stud Q52 and serves to exert a pressure tending to maintain the pawl plate its so that projection I42 remains in operative contact with lug I43 on rock bar 48.

During the grinding operation on a cam blank, the rock bar is oscillated so that lug I43 moves between full line position (Fig. 3) and dotted line position I iSa. During this movement, the projection hi2 of the pawl carrying plate I38 is oscillated to move the pawl i39 over the teeth of ratchet wheel I33. This movement continues until the mercury switch I35 has rocked so that mercury M l contacts with mercury I A la to energize solenoid I2I. This serves to actuate valve 83 and cause a further rocking movement of bar 48 to swing the rock bar to an inoperative position. Then, the feed wheel EI is rotated to move the grinding wheel rearwardly. This movement of the feed wheel shifts valve i l and admits fluid pressure to cylinder chamber 88 to rock lever 6| from position {Ella to tlb. At the same time, the projection I 22 of pawl carrying plate I38 is rocked into position M25. This movement serves to cause a pin 5175 of pawl I39 to ride up over a cam lid on a fixed. plate I56 so as to withdraw the pawl 538 from engagement with the ratchet teeth I133. The cam H5 is formed on plate I58 which is held against rotation by a pin I 49 (Fig. 6). This same rocking movement of the projection Hi2 into position I421) alsoserves to cause a cam surface I78 formed on pawl carrying plate I33 to move and engage pin I on the safety pawl I45 so as to rock the pawl I45 out of engagement with the ratchet wheel !33.

As soon as the pawls I 39' and I45 have been withdrawn from engagement with the teeth of the ratchet wheel I33, the released tension of a spring I85 interposed between a stud 86 on the pawl carrying plate I38 and a stud I8? on the rock bar supporting bracket t! serves to rapidly move the pawl carrying plate 338 in a clockwise direction so as to return it to its initial or starting position.

This return movement of the pawl carrying plate I38 is rapid, and it is desirable to provide a suitable cushioning device to prevent shocks and vibrations when the plate reaches its normal position.

In the preferred construction, as illustrated in the drawings, a spring pressed plunger I53 engages aprojecting portion H54 of the ratchet plate I33 and serves to prevent any shocks or vibrations as the plate is moved by the rock bar. In order to further cushion the motion of the spring pressed plunger 253, the other end of the plunger 53 is arranged to serve as a dash pot piston I55 which is slidably mounted within a dash pot cylinder 55?. When the dash pot piston I56 moves toward the left, as viewed in Fig. 3, fluid within the dash pot piston is forced outwardly through a port I58 into a reservoir I59.

Nose lifting dcvice-operatice or inoperative In setting up the machine or for certain grinding operations, it is desirable that a control means be provided so that the nose lifting device may be readily rendered operative or inoperative, as desired. As illustrated in the drawings, a manually operable lever W5 is pivotally mounted on a stud I 555 which is fixed to the headstock frame 52. The lower end of the lever is provided with an arrow point i6? which is arranged to engage a spring-pressed roller I68 which serves to maintain the lever H65 in one of two positions. In the position illustrated in Fig. l, the nose lifting device is operative. When it is desired to render the device inoperative, the lever N55- is manually moved in a clockwise direction (Fig. l) which serves to move the lower end of the lever toward the left, as viewed in Fig. l. The lower end of the lever I85 is provided with a pin I'Ill which engages a groove III in a spool I72 mounted on the end of a rod I13 which is fixed to the non-rotatable plate 14?. Shifting the lever H65 in a clockwise direction (Fig. l) serves to cause a movement of plate I 4?, the ratchet I33", pawls I39 and M5 together with the mercury switch i3fi and its mounting plate Hi2 towards the left until the projection of the pawl plate I38 is out of the path of the lug- M3 on rock bar Mil. When the projection 952 is moved out of the path of the lug I45, the nose lifting device is rendered inoperative and the machine may be operated manually or automatically without the operation of the nose lifting device, if desired.

Automatic indexingmaster cam roller In order that successive cams on the shaft 45 may be accurately ground to the desired size and shape and in the proper timed relation with the shaft 45, it is necessary to employ a plurality of master cams, one for each cam 66 on the product camshaft 45. In grinding successive cams, it is necessary that the master cam roller 48 be shifted longitudinally into operative relation with the master cam corresponding with the product cam on the shaft 45 to be ground. In the preferred construction, an. automatically operable mechanism, which is actuated in timed relation with the table traverse movement, so that when the work table 30 is traversed longitudinally to position a product cam 46 in oper ative relation with the grinding wheel I3, the master cam roller 43 will likewise be automatically shifted longitudinally into operative relation with the corresponding master cam 44, is provided. The mechanism illustrated in the present drawings is identical with that shown in the prior patent to Trefethen, et al. No. 1,783,755 dated December 2, 1930, to which ref-- erence. may be had for a complete disclosure, if desired.

-As illustrated in the drawings (Figs- 1 and 2), a slidably mounted yoke I09 is adapted to engage opposite sides of the master cam roller 48. The yoke I00 is fixed to the end of a rack bar I0! which is arranged to slide longitudinally in a guiding member I02. A dog supporting bar I03 is fixedly mounted by means of a bracket I84 to the base it. The bar 5633 is provided with a plurality of adjustable dogs E05 which are adjustably arranged on the bar so as to correspond with the spacing of earns 45 on the product shaft 45. A star wheel I05 is rotatably supported on a bracket It! which in the present illustration is a depending portion of bracket 5|. The star wheel M36 is mounted on the end of a shaft IE8. The star wheel I06 is arranged in the path of the dogs Hi5 so that when the table 30 is traversed longitudinally, engagement of the dogs I85 serves to cause a partial rotation of the star wheel Hit. The shaft 08 carries a gear I539 which in turn meshes with a gear I I0 mounted on a stud Ill. The gear H0 in turn meshes with a pinion H2 mounted on a stud H3. The stud 5 I3 also carries a pinion II4 which is integral with pinion H2. It will be readily apparent from the illustration and description that when the table 30 is traversed longitudinally to position the product camshaft .45, the dogs I05 engaging the star wheel I06 cause an indexing movement of the master cam roller 48 by means of the gear I09, gear IIO, pinion H2, pinion H4, rack IOI and yoke I00. It will be thus seen that when the table 30.is moved in either direction, the dogs serve to automatically index the roller 48 longitudinally so that when any cam 46 on the camshaft 45 is brought into operative relation with the grinding wheel I3,v the master cam roller 48 is located in proper relation with the corresponding master cam 44.

While the present invention has been described as applied to a manually operable cam grinding machine, I do not desire to be so limited in interpreting the scope of the invention. My invention is equally applicable to an automatic cam grinding machine of the type shown in the U. S. Patents Nos. 1,840,088 and 1,945,588 and the copending application Serial No. 605,707.

The operation of this device will be readily apparent from the foregoing disclosure. In setting up the machine, the stop abutment 22 of the feed mechanism is adjusted to properly size the cams 48. The dogs I05 are adjusted to index the master cam roller 44 in proper timed relation with the cams 46 so that when the table traverses, the master cam roller 48 is moved into operative relation with the master cam 44 corresponding with the cam 46 to be ground. The plate I32, carrying the mercury switch I30, is then adjusted relative to the ratchet wheel I33 by means of an adjusting screw I 84 which is threaded into the ratchet plate I33 and passes through an arcuate slot I83 in the plate I32. This arrangement permits a fine adjustment of the mercury switch I30 so that the cam being ground may be rotated and rocked a predetermined number of rotations before the mercury switch becomes operative to energize solenoid I2I and shift the valve 83 and admit fluid under pressure to cylinder chamber I25 to cause a separation of the master cam 44 and follower 48 and corresponding separation of the product cam 35 and grinding wheel is when any predetermined portion, such as the high point or nose of the cam 46, is in engagement with the grinding wheel Successive cams may then be ground and the cam withdrawn from the grinding wheel when the high or nose of the cam is in operative engagement with the wheel.

-Having thus de -::ihed theinvention, what is claimed as new desired to secure by Letters Patent is:

l. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse movement between said wheel and work support to grind successive cams to a predetermined size, means to traverse said work support and wheel longitudinally relative to each other to position the wheel and cam blanks, means to cause a ated in timed relation with the rotation of the work support automatically to actuate said mechanism to separate the wheel and cam being ground when a predetermined point of the cam is in engagement with the wheel after a predetermined grinding operation has been completed.

2. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse movement between said wheel and work support to grind successive cams to a predetermined size, means to traverse said work support and wheel longitudinally relative to each other toposition the wheel and cam blank, means including a plurality of master cams and a follower to cause a relative transverse movement between the wheel and work to grind successive cams to a pre" determined contour, mechanism to relatively move the grinding wheel and camshaft to an inoperative position and a nose lifting device actuated in timed relation with said transverse movement to automatically control said mechanism and separate the wheel and cam being ground when a predetermined point of the cam is in operative engagement with the wheel after a predetermined grinding operation has been completed.

3. A cam grinding machine having a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other, means to cause a transverse movement between the wheel and work support to grind successive cam blanks to a predetermined size and contour, means to cause a relative longitudinal movement between the wheel and work support to position successive cams in operative relation with the grinding wheel, and electrically controlled means to cause a separating movement between the wheel and cam blank when the high point or nose of the cam is in operative contact with the periphery of the grinding wheel after the cam blank has been ground to a predetermined size.

4. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other, means to cause a relative transverse movement between the wheel and work support to grind a cam blank to a predetermined size and contour, means to cause a relative longitudinal movement between the wheel and work support to position successive cams in operative relation with the grinding wheel, and automatically actuated electrically controlled fluid pressure mechanism actuated in timed relation with the rotation of the work support to cause a separating movement between the wheel and work support when the high point or nose of the cam is in a predetermined position relative to the grinding wheel after the cam has been ground to a predetermined size and contour.

5. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse movement between the wheel and work support to grind successive cams to a predetermined size, means to traverse said work support and wheel longitudinally relative to each other to position the wheel and cam blank, means including a plurality of master cams and a follower to cause a relative transverse movement between the wheel and work to grind successive cams to a predetermined contour, and automatically actuated fluid pressure mechanism to separate the wheel and work support, and means actuated by and in timed relation with said transverse movement to control said-fluid pressure mechanism so as to cause a separating movement between the wheel and work support when the high point or nose of the master cam is in a predetermined rotary position relative to the grinding wheel after the cam has been ground to a predetermined size and contour.

6. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse movement between the wheel and work support to grind successive cams to a predetermined size, means to traverse said work support and wheel longitudinally relative to each other to position the wheel and cam blanks, means including a plurality of master cams and a follower to cause a relative transverse movement between the wheel and work to grind successive cams to a predetermined contour, and electrically controlled means to automatically separate the wheel and cam blank when the high point or nose of the cam is in operative engagement with the periphery of the wheel after the cam blank has been ground to a predetermined size and contour.

7. A cam grinding machine having a rotatable grinding wheel and a rotatable work support which are movable transversely and longitudinally relative to each other, means to cause a relative transverse movement between the wheel and Work support to grind a cam blank to a predetermined size and contour, means to relatively traverse said wheel and work support longitudinally to position successive cam blanks in operative relation with the grinding wheel, separating mechanism to separate the wheel and cam being ground, automatically actuated timing mechanism which is actuated in timed relation with the rotation of the work support to automatically separate the wheel and cam being ground when the cam is in a predetermined rotative position relative to the grinding wheel after it has reached a predetermined size and contour, and means to render said last mentioned means inoperative when desired.

8. A cam grinding machine comprising a rotatable grinding wheel and a rotatable work support which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft,

means to cause a relative transverse movement I between the wheel and work support to grind successive cams to a predetermined size, means to traverse the work support and wheel longitudinally relative to each other to position the wheel and cam blank, means including a plurality of master cams and a follower to cause a predetermined transverse movement between the wheel and work to grind successive cams to a predetermined contour, separating means to separate the grinding wheel and cam being ground, automatically actuated timing mechanism which is actuated in timed relation with said transverse movement to automatically actuate said separating means to separate the wheel and cam being ground when a predetermined point of the cam is in engagement with the wheel after a predetermined grinding operation has been completed, and manually operable means to render said lifting device inoperative when desired.

9; A cam grinding machine comprising a rotatable grinding wheel and a table which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse feeding movement between the wheel and work support to grind successive cams to a predetermined size, a work support pivotally mounted on said table, a rotatable camshaft support thereon, means including a plurality of master cams and a follower to rock said work support and cause a relative approaching and receding movement between the grinding wheel and cam blanks to grind the cam blanks to a predetermined contour, means to rock said support to an inoperative position, and automatically actuated mechanism which serves to separate the cam being ground and the grinding wheel when the cam blank is in a predetermined rotative position relative to the grinding wheel.

10. A cam grinding machine comprising a rotatable grinding wheel and a table which are movable longitudinally and transversely relative to each other to successively grind a plurality of cams on an integral camshaft, means to cause a relative transverse feeding movement between the wheel and work support to grind successive cams to a predetermined size, a work support pivotally mounted on said table, a rotatable camshaft support thereon, means including a plurality of master cams and a follower to rock said work support and cause a relative aproaching and receding movement between the grinding wheel and cam blanks to grind the cam blanks to a predetermined contour, means to rock said support to an inoperative position, and automatically actuated mechanism which serves "to separate the the cam being ground. and the grinding wheel when the high point or nose of the cam is in operative engagement with the grinding wheel.

11. A cam grinding machine having a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a work support pivotally mounted on said table and arranged to rotatably support a camshaft having a plurality of integral cams thereon, means to cause a transverse movement of the grinding wheel relative to said support to grind successive cam blanks to a predetermined size, means to cause a relative longitudinal traversing movement between the wheel and camshaft to position successive cams in operative relation with the wheel, means including a plurality of master camsand a follower to cause a rocking movement of said work support to grind successive cams to predetermined contours, means including a fluid pressure cylinder operatively connected to rock said support to an inoperative position, and automatically actuated mechanism to separate the grinding wheel and cam blanks when the high point or nose of the cam is in operative contact with the grinding wheel.

12. A cam grinding machine comprising a rotatable grinding wheel a transversely movable slide to support said wheel, a longitudinally movable table, and rotatable work support pivotally mounted on said table and arranged to rotatably support a camshaft having a plurality of cams formed integrally therewith, means to cause a relative transverse movement of the grinding wheel slide to grind successive cams to a predetermined size, means to traverse said table longitudinally to position successive cams in operative relation with said grinding wheel, means including a plurality of master cams and a follower operatively arranged to cause a rocking movement of said support to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively connected to rock said. support to an inoperative position, and electrically actuated means to control said fluid pressure system so as to separate the cam being ground and the grinding wheel only when the high point or nose of the cam is in operative contact with the grinding wheel.

13. A cam grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a rotatable work support pivotally mounted on said table and arranged to rotatably support a camshaft having a plurality of cams formed integrally therewith, means to cause a relative transverse movement of the grinding wheel slide to grind successive cams to a predetermined size, means to traverse said table longitudinally to position successive cams in operative relation with said grinding wheel, means including a plurality of master cams and a follower operatively arranged to cause a rocking movement of said support to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively connected to rock said support to an inoperative position, and electrically actuated means operated in timed relation with the rocking of said support to control said fluid pressure system so as to separate the cam being ground and the grinding wheel only when the high point or nose of the cam is in operative contact with the grinding wheel.

14. A cam grinding machine comprising a retatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a pivotally mounted work support on said table arranged to rotatably support a camshaft having a plurality of cams formed integrally therewith, means to traverse said table longitudinally to position successive cams in operative relation with the grinding wheel, means to cause a relative transverse movement between the grinding wheel and work support to grind successive cams to a predetermined size, means including a plurality of master cams and a follower arranged to cause a transverse movement between the wheel and work support so as to grind successive cams to a predetermined contour,means including a fluid pressure piston and cylinder operatively connected to rock said work support and separate the camshaft and the grinding wheel, a valve arranged to control the admission of fluid to said cylinder, and electrically actuated means operated in timed relation with the rocking of said support to actuate said valve and cause a separation of the cam being ground and the grinding wheel only when the nose of the cam being ground is in operative contact with the periphery of the grinding wheel.

15. A cam grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a pivotally mounted Work support on said table arranged to rotatably support a camshaft having a plurality of cams formed integrally therewith, means to traverse said table longitudi nally to position successive cams in operative relation with the grinding wheel, means to cause a relative transverse movement between the grinding wheel and work support to grind successive cams to a predetermined size, means including a plurality of master cams and a follower arranged to cause a transverse movement between the wheel and work support so as to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively connected to rock said work support and separate the camshaft and the grinding wheel, a valve arranged to control the admission of fluid to said cylinder, a solenoid operatively connected to actuate said valve, and electrically actuated means operated in timed relation with the rocking of said support to energize said solenoid and actuate said valve to cause a separation of the cam being ground and the grinding wheel only when the nose or high point of the cam being ground is in operative contact with the periphery of the grinding wheel.

16. A cam grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a pivotally mounted work support on said table arranged to rotatably support a camshaft having a plurality of cams formed integrally therewith, means to traverse said table longitudinally to position successive cams in operative relation with the grinding wheel, means to cause a relative transverse movement between the grinding wheel and the Work support to grind successive cams to a predetermined size, means including a plurality of master cams and a follower arranged to cause a transverse movement between the wheel and work support so as to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively connected to rock said work support and separate the camshaft and the grinding wheel, a valve arranged to control the admission of fluid to said cylinder, a solenoid operatively connected to actuate said valve, an electric switch operatively connected with said solenoid, and means operated in timed relation with the rocking of said sup-port to actuate said switch and cause a separation of thecam being ground and the grinding wheel only when the nose of the cam being ground is in operative contact with the 10 periphery of the wheel.

17. A cam grinding machine comprising a rotatable grinding wheel, a transversely movable slide to support said wheel, a longitudinally movable table, a pivotally mounted work support on said table arranged torotatably support a camshaft having a plurality of cams formed integrally therewith, means to traverse said table longitudinally to position successive cams in operative relation with the grinding wheel, means to cause a 0 relative transverse movement between the grinding wheel and work support to grind successive cams to a predetermined size, means including a plurality of master cams and a follower arranged to cause a transverse movement between the wheel and work support so as to grind successive cams to a predetermined contour, means including a fluid pressure piston and cylinder operatively connected to' rock said work support and separate the camshaft and the grinding Wheel, a valve ar ranged to control the admission of fluid to said cylinder, a solenoid operatively connected to actuate said valve, a mercury tube switch operatively connected with said solenoid, a pivotally mounted support for said switch, and means operated in timed relation with the rocking of said support to intermittently rock said switch and cause a separation of the cam being ground and the grinding wheel only when the nose of the cam being ground is in operative contact with the periphery of the wheel.

'18. In a cam grinding machine having a pivotally mounted camshaft support and master cams and a follower to control the rocking movement of said support, a control device including an electric switch, means including a pawl and ratchet mechanism to actuate said switch, means actuated by the rocking movement of said camshaft support intermittently to index said ratchet wheel to actuate said switch, and an electrically controlled mechanism operated when the switch is actuated to cause a separation of the master cam follower when the high point of the cam being ground is in engagement with the wheel.

19. In a cam grinding machine having a pivotally mounted camshaft support and master cams and a follower to control the rocking movement of said support, a control device including an electric switch, means including a pawl and ratchet to actuate said switch, connections between said camshaft support and pawl to actuate the same in timed relation with the rocking of said support, and an electrically. controlled mechanism operated by said switch to rock said support to an inoperative position after a predetermined grinding operation has been completed.

HERBERT A. SILVEN.

Images