US3057120A

US3057120A - Cam grinding machine

Info

Publication number: US3057120A
Application number: US60261A
Authority: US
Inventors: Cyrus S Yingst
Original assignee: Heald Machine Co
Current assignee: Heald Machine Co
Priority date: 1960-09-30
Filing date: 1960-09-30
Publication date: 1962-10-09
Anticipated expiration: 1979-10-09

Description

Oct. 9, 1962 c. s. YINGST CAM GRINDING MACHINE 7 Sheets-Sheet l Original Filed April 22, 1958 S e R n W MW M W.

Oct. 9, 1962 c. s. YINGST 3,057,120

CAM GRINDING MACHINE Original Filed April 22, 1958 7 Sheets-Sheet 2 our INVENTOR. Cyrus 5. Yin'gst BY mm 213% 1952 c. s. YINGST CAM GRINDING MACHINE '7 Sheets-Sheet 3 Original Filed April 22, 1958 INVENTOR. Cyrus 5. Yingst BY J Oct. 9, 1962 c. s. YINGST 3,057,120

CAM GRINDING MACHINE IN V EN TOR.

Cyrus 5. Yingst 1962 c. s. YINGST CAM GRINDING MACHINE Original Filed April 22, 1958- '7 Sheets-Sheet 5 T. 5 p mdJ e Tn N T e WY 0 8 N S 5 rlllu U QI/ WJ r7 W m Oct. 9, 1962 c. s. YINGST CAM GRINDING MACHINE Original Filed April 22, 1958 '7 Sheets-Sheet 6 INVENTOR Cyv-us S. Yz'ngst B United States Patent F 3,057,120 CAM GRINDING MACHINE Cyrus S. Yingst, Cincinnati, Ohio, assignor to The Heald Machine Company, Worcester, Mass, a corporation of Delaware Continuation of application Ser. No. 730,105, Apr. 22, 1958. This application Sept. 30, 1960, Ser. No. 60,261 20 Claims. (Cl. 51-101) This invention relates to a cam grinding machine and more particularly to apparatus arranged to finish noncircular cylindrical surfaces and the like by grinding. This application is a continuation of my patent application Serial Number 730,105 filed April 22, 1958, now abandoned.

In the generation of surfaces of revolution of noncircular cross-section with a grinding machine, it is usual practice to move the wheel radially inwardly and outwardly in response to the movement of a follower passing over the surface of a master cam which has the same general shape as the surface to be generated. The chief difficulty encountered with this method of operation is that, as the wheel wears or is dressed, a suitable compensation must be made for the fact that the relationship between the surface of the follower and the surface of the wheel has been changed. Several methods have been proposed in the past for accomplishing this compensation but none of them have proved to be entirely adequate. The difiiculties which have been experienced with the prior art machines of this type have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the present invention to provide a cam grinding machine having automatic compensation for wheel dress and wear.

Another object of this invention is the provision of an internal cam grinding machine of the follower type in which compensation is made for dressing of the wheel.

A still further object of the present invention is the provision of a cam grinding machine including interlocked cycling equipment for regulating the operation of the apparatus.

It is another object of the instant invention to provide a cam grinding machine of rugged desgn which will require a minimum of maintenance and will give a long life of useful service.

A further object of the invention is the provision of a cam grinding machine which is capable of grinding its own master cams.

Another object of the invention is the provision of a cam grinding machine providing for the use of hydraulic power in clamping and unclamping the workpiece.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself as to its objects and advantages, the mode of its operation, and the manner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which:

FIGURE 1 is a perspective view of a cam grinding machine embodying the principles of the present invention,

FIGURE 2 is a vertical sectional view of a portion of the apparatus taken on the line IIII of FIGURE 1,

FIGURE 3 is a horizontal sectional view of the apparatus taken on the line IIIIII of FIGURE 2,

FIGURE 4 is a vertical sectional view of the apparatus taken on the line IVIV of FIGURE 3,

FIGURE 5 is a vertical sectional view of the apparatus taken on the line VV of FIGURE 3,

FIGURE 6 is a schematic view of certain hydraulic and pneumatic circuits associated with the invention, and

3,051,120 Patented Oct. 9, 1962 FIGURE 7 is a graphical illustration of the path of movement taken by the grinding wheel during the grinding cycle.

In the description which follows, the expression longitudinal and transverse are used to indicate those directions relative to the axis of the grinding wheel of the machine.

Referring first to FIGURE 1, wherein is best shown the general features of the invention, the grinding machine, indicated generally by the reference numeral 10, is shown as comprising a base 11 on which is mounted a wheelhead 12 adapted to support and rotate a cylindrical grind ing wheel 13. A feed mechanism 14 of theusual type is associated with the wheelhead to provide for transverse advancement of the wheel into the workpiece. Also mounted on the base 11 is a workhead 15 consisting of a housing 16 on which is mounted a motor 17. Also included in the workhead 15 is a screw compensating apparatus 13; a follower mount 19, and a bridge 21. Mounted on the base 11 is a control housing 22 containing the usual electrical, hydraulic, and pneumatic controls. The wheelhead 12 rests on a wheelhead table 20 which is mounted for longitudinal motion on the base 11 and slides under the workhead 15 in a gap formed by a suitable recess 23 formed in the base 11 and bridged by the bridge 21. The screw compensating mechanism 18 is immovably fixed on the bridge 21 and therefore remains fixed relative to the base 11. The housing 16, however; is suitably mounted in a manner which will be described further hereinafter for transverse sliding motion relative to the bridge 21 and to the base 11. It is not, however,- capable of longitudinal motion relative to the members. The follower housing 19 is suitably mounted on the screw compensating mechanism 18, as will be described more fully hereinafter, and is capable of longitudinal motion relative thereto but is not capable of transverse motion; its movement, therefore, is similarly determined with respect to the bridge 21 on the base 11.

Referring now to FIGURE 2, the base 11 is shown with its recess 23 and the bridge 21 mounted across the recess 23. The screw compensating mechanism 18 is shown firmly mounted on the bridge 21, and connected by the screw 24 to the follower housing 19. The main housing is shown as having a rear wall 25 and a bottom wall 26 which rests on transverse ways solidly mounted on bridge 21. The bottom wall 26 has a first portion 27 and a second portion 28 each of which is mounted for sliding in the usual way on hardened

steel rails

29 and 31, respectively, mounted on the bridge 21. A considerable space separates the first and second portions of the bottom wall 26. The screw compensating mechanism 18 is provided with two

vertical walls

32 and 33. The wall 32 extends outboard of the first portion 27' of the bottom wall 26 of the main housing 16. The vertical wall 33, however, extends downwardly to the bridge 21 through the gap between the first portion 27 and the second portion 28 of the bottom wall 26. Mounted between the first portion 27 and the second portion 28' of the bottom wall 26 of the main housing 16 is a support 34. A suitable V-way is formed on the face of the first portion 27 of the bottom wall in the part thereof which faces the other portion; a lug 35 extends from the support 34 to engage the V-way. A similarly formed abutment 36 extends from the other side of the support 34 to engage the gib 37 which rests on a supporting bridge 103 formed as part of the horizontal wall connecting portions 27 and 28 of the main housing 16. The gib 37 is formed with an inclined surface which engages a similarly formed surface on the abutment 36 and is adjustable by means of a screw 55 which extends through the portion 28 of the bottom wall 26 of the main housing. It can be seen, then, that the support 34 is capable of transverse movement on occasion relative to the base 11.

The housing 16 is provided with a hinged connection to a motor support plate 39. The motor support plate is capable of pivotal movement about a horizontal axis passing through the rear wall 25 of the housing. The main housing 16 is also provided with a front wall 41 which carries a split ring 42. This ring is adapted to carry a rotating and transversely slidable element which will hereinafter be referred to as the slide head, comprising a yoke 63 having diametrically opposite journals 64 and 65 slidably arranged in the split ring 42, a workpiececarrying ring 61 consisting of a journal 138 and work carrier plate 139 attached thereto at the right side with a master cam 43 at its left side. The journal 138 and the plate 139 define an annular groove 62 around the periphery of the ring 61. The master cam is of a generally tubular construction having V-shaped grooves 44 formed on its outer surface for engagement by a V-belt drive and on its inner surface is formed with a conical master surface 45, whose average or pitch line is in the shape of the desired cam to be ground.

Mounted in the follower housing 19 is a shaft 46 carried for rotative movement in suitable bearings. The right end of the shaft 46 extends from the housing 19 and has mounted thereon a follower 47 having a frusto-conjcal surface for engagement with the master surface 45 of the master cam 43. The shaft 46 is not capable of longitudinal motion within the housing 19 and at its left end it is provided with a recess 48 permitting the entrance of the screw 24. Fastened to the end the housing 19 is a nut 49 having threads which closely engage the screw 24 which is also provided with a back-lash take-up member 51 of well-known construction. The screw compensating mechanism housing 18 is provided with a gear box 52 and the screw 24 is provided with a shaft portion 53 which is carried in suitable hearings in the gear box 52 for rotation relative thereto. A hand wheel 54 is mounted on the left hand end of the shaft portion 53 as it extends from the gear housing 52.

Mounted in the key support 34 is a key 56 of elongated form having a downwardly depending shaft 57 which is suitably mounted in bearings for rotation in the support 34. A lock nut provides for adjustment of the bearings on the shaft 57.

In FIGURE 3 it can be seen that a dressing tool 58 is integrally joined to the housing 16 and moves with it transversely of the base. In this figure is also shown a diagonal slot 59 in which the key 56 resides. The slide is formed in the bottom portion of the follower housing 19, as is best shown in FIGURE the slot is, of course, set at a substantial angle to the axis of the shaft and coincides with the angle of the follower 47.

The yoke 63 is provided with integral journals 64 and 65 extending from diametrically opposite sides there-of. The split ring 42 is provided with bores 66 and 67 adapted to receive the journal 64 and 65, respectively. The journal 65 is provided at its outer end with a piston 68 which is carried in a cylinder 69. Adjustable stop screw '11 extends through the wall 41 into the bore 66 in opposition to the end of the journal 64. The stop screw 71 is actuated by a crank handle 72 accessible from the front of the machine. A portion of the journal 65 is reduced to form a reduced portion 73 and an oil passage enters the portion of the bore 67 occupied by the reduced portion 73. A passage 74 extend through the reduced portion 73 and intersects a longitudinal passage 75 extending axially through the journal and terminating in a groove 76 formed in the cylindrical surface of the yoke 63 where it engages a groove 137 in journal 138. The groove 137 is connected by a hole to a longitudinal passage 77 which, in turn, leads to one side of a workpiece holder 78 (shown best in FIGURE 6) which normally occupies the right hand side of the plate 139. Similarly, the journal 64 is provided with a reduced portion 79 to which an oil passage has access through the housing 16, the reduced portion being provided with a passage 81 extending entirely therethrough. The passage 81 intersects a bore extending longitudinally of the journal 64 and terminating inwardly in a groove 83. The groove 83 is connected by small passages to a longitudinal passage 84 leading to the workpiece holder 7 8 in a manner which will be described more fully hereinafter.

Referring now to FIGURE 5, the motor plate 39, as has been shown, is hinged to the top of the rear wa1l25 of the main housing 16. The other side of the plate 39 is supported by the top part of a forward wall 85 of the housing by means of an adjustable connecting screw 86 to permit leveling of the motor 17 and to permit the adjustment of belt tension. The motor output shaft is connected through flexible belts 87 to the input shaft of a gear reduction unit 88, the output shaft of which is connected through V-belt 89 to the grooves 44 forming the outer surfaces of the master cam 43. In FIGURE 5 is very well shown the manner in which the bridge 21 straddles the recess 23 in the base 11 and permits the wheel head table 29 to pass in the space left thereby between. At its forward side the key support 34 is provided with a threaded section 91 encasing a screw 92 which is supported by bracket 146 attached to portion 85 of the housing 16 and adjustable by means of a hand wheel 93 (see FIGURE 3). As is evident in this figure, there are two sets of gi-bs 37 at widely spaced points bearing on opposite ends of the support 34.

An abutment 94 extends upwardly from the bridge and is engaged by the end of a piston rod 95 actuated by a piston 96 residing in a cylinder 97 formed in the lower part of the main housing 16. It can be seen that the follower mount 19 is mounted for longitudinal sliding motion on a horizontal extension 98 of the compensating mechanism housing 18. This extension 98 appears in FIGURE 2 as being connected to the

vertical walls

32 and 33 and is supported by these walls. FIGURE 5 shows very well how the bottom wall 26 of th main housing 16 is divided into a forward portion 99 and a rearward portion 161 through which the supporting wall 33 extends in order to engage key 56 with diagonal slot 59. This figure shows the manner in which a bridge 1412 extends downwardly from the portion 99 to receive the gib 37 while a similar bridge 103 extends downwardly from the portion 161 to receive the other gib 37.

In FIGURE 4 it can be seen that the gear box 52 0f the compensating mechanism housing 18 is provided with a cylinder 164 in which is slidably received a piston 165. The piston 105 is provided with a piston rod 166 having rack teeth 167 formed thereon and slidably mounted in a bore 108. At the upper part of the gear box is mounted a threaded stop 169 which engages the end of the piston rod. The stop 169 is adjustable axially of the bor 198 and indicia are formed thereon to determine a proper setting, as will be described hereinafter. The rack teeth 107 of the piston rod 106 engage a segmental pinion 111 which is free to rotate on a hub extension of the gear housing 52. A ratchet wheel 112 mounted on the shaft 53 and keyed thereto is engaged by a pawl mechanism 113 which acts to rotate the ratchet wheel 112 in one direction of movement only.

In FIGURE 6 the work piece holder 78 is shown as having a series of clamps 114 for clamping a workpiece 115. Each clamp is an extension of the piston rod of one of the pistons 116 which is slidably movable in its individual cylinder 117. When the workpiece holder 78 is fastened to the plate 139, as it normally is, the right hand end of each cylinder 117 is connected to the oil passage 77 while the left hand end of each cylinder 117 is connected to the passage 84 formed in the journal 138. A pressure oil line 118 is connected to a source of oil under pressure, not shown, while a drain line 119 returns the oil to a sump, not shown. The line 118 is attached to a four-way solenoid valve 121. A drain line .5 119 is connected to the drain ports of this valve. One output port of the valve 121 is connected by a line 123 to the follower compensation cylinder 104, while the other output port of the valve 121 is connected by a line 124 to the upper end of the same cylinder. The line 124 is connected by a line 125 to the rearward end of the back-lash cylinder 97, the forward end of which is connected by a line 126 to the drain line 119. A conduit 127 is connected to a source of air under pressure and through a solenoid-actuated valve 128 to the rearward end of the cylinder 69. The valve 128 includes an actuating coil 129. An opening at the forward end of the cylinder 69 permits the escape of air forward of the cylinder 68. A line 131 connects the pressure oil line 118 to one side of a manual-type, four-way valve 132 having an actuating handle, not shown, which is readily accessible to the opera-tor of the machine. One output port of the valve 132 is connected by a line 133 through the housing 16 and various passages to the passage 77 associated with the workpiece holder 78. The other output port of the valve 132 is connected by a line 134 through the housing 16 and various passages to the passage 84 and the workpiece holder 78. The last port of the valve 132 is connected by a line 135 to the drain line 119.

It will be understood that the machine contains many elements that are necessary for its operation but which form no part of present invention and, therefore, have not been described in detail. For instance, means are provided for moving the wheelhead table 29 and the wheelhead 12 on an extended longitudinal traverse to withdraw the wheel from the workpiece to cause it to enter the workpiece, and to cause is to pass over the dressing tool 58 on occasion. Also, means is provided for reciprocating the wheel in the workpiece during the grinding operation, as is the usual practice in such machines. Furthermore, it will be understood that the feed mechanism 14 associated with the wheel head for traversing the wheel 13 laterally of the head of the machine is also provided with various switches and actuating mechanisms for bringing into play various par-ts of the grinding cycle. For instance, at a suitable time a switch will be actuated to energize the coil 122 of the solenoid valve 121 and the coil 129 of the valve 128.

The operation of the invention will now be readily understood in view of the above description. Let us now assume that workpiece has just been finish ground; the table 20 carrying the wheelhead 12 has run out to the far right or rest position. At point H the table 20 operates a switch 136 which sets the compensating cycle in motion.

Solenoids

129 and 122 of valves 128 and 131, respectively, all are energized. Air in cylinder 69 goes to exhaust, releasing pressure from the piston 68, and, therefore, releasing the force between the master cam 45 and the follower 47. The plunger in the valve 121 shifts, allowing oil in the

lines

124 and 125 to go to exhaust via line 119. This releases pressure on the rearward side of the piston 96 and on the abutment 94. This further releases the pressure between the key 56 and the diagonal slot 59 in which key 56 resides. Pressure oil from line 118 passing through line 123 has reached the lower side of the cylinder 104 causing the compensating piston 105 to move upwardly in the cylinder 104, so that the teeth 107 on the piston rod 106 engages the teeth on the segmental pinion 111 and move the segment a predetermined amount, the amount being determined by the setting of the compensation adjusting screw 109. The pinion operates the pawl mechanism 113 to actuate and rotate the ratchet wheel 112. This turns the screw 24 and moves the follower housing 19 and the follower 47 to the left in FIGURE 2. This movement causes the mean diameter of the follower 47 to 'be reduced so that the master cam 44 will have its surface 45 somewhat closer to the axis of the shaft 46 at all times during its rotation. Referring to FIGURE 3, it will be seen that the movement of the follower housing 19 to the left (carrying the slot 59 with it) causesmovement of the key 56 toward the forward part of the machine; since the key is mounted in the support 34, this latter member travels to the right in FIGURE 5. Since the screw 92 engages a threaded portion of the support 34 and is constrained at its outer support by being fastened to front portion of the housing 16, housing 16 thus moves to the right on the base 11 and carries the dressing tool 58 with it. It will be understood, of course, that the follower housing 19 is mounted on an extension 98 of the compensation housing 18 which, in turn, is bolted to the bridge 21 and does not partake of this movement. When the table reached the point H and set the compensation cycle in motion, as aforementioned, the operator of the machine removes the finished workpiece 115 from the work holder 78 and replaces it with a workpiece which is to be finished. To accomplish this, the valve 132 is shifted manually to such a position that pressure oil from the line 118 passes through the line 131 and the line 134 to the passage 84 and the inner end of pistons 116. This moves the clamps 114 to their outward position, thus releasing the old or finish workpiece 115. When the new workpiece is in place, the operator again shifts the valve 132 manually, causing the pressure oil to appear in the passage 77 and at the outer ends of the cylinders 117 to cause the clamps 114 to move inwardly and hold the workpiece.

The operator now moves a suitable lever to start the table 20 carrying the wheelhead 12 and wheel 13 toward the grinding position. The moving of the lever causes the closing of a switch, not shown, which deenergizes the coils 129 of the valve 128 and also the coil 122 of the valve 121. Valve 128 causes air pressure to enter the cylinder 69 forcing the piston 68 forwardly to engage the trunnion 65 on the yoke 63. The yoke 63 carries the journal 138 with master cam 43 and the work holding means 78 and is moved forward until the surface 45 of the master cam 43 engages the surface of the follower 47, and presses the surfaces firmly together.

The de-energization of the coil 122 and the movement of the valve 121 causes pressure oil to flow to the upper side of the cylinder 104 through the line 124, causing the piston 195 and the rod 106 to move downwardly, resetting the compensating mechanism for the next compensation. Pressure oil also flows to the rearward end of the cylinder 97 through the line 125. This causes the piston rod to press firmly against the abutment 94 which, it will be remembered, extends upwardly from the bridge 21. This pressure, of course, tends to push the housing 16 rearwardly on the base and is in direct opposition to the forces between the key 56 and slot 59; the net effect of the action of the piston 96 and the cylinder 97 is to remove any lback-lash that may exist between the key 56 and the slot 59. As the table travels toward the grinding position, an interlock is provided to assure that the air pressure in the cylinder 69 is up to full pressure before the workhead motor 17 starts rotating in order to prevent slippage between the master cam surface 45 and the follower 47. As the motor begins to drive the master cam 43 at a suitable speed,- the master cam rotates with the journal 138. Since the plate 139 attached thereto carries the "work-holding means 78, both the master cam and the work-holding means rotate and move transversely in unison.

The axis of the follower 47 remains stationary, although the follower is, of course, rotating in the shaft bearings. The yoke 63, carrying the journal 138, partakes of a transverse motion by sliding on the journals 64 and 65, thus duplicating the shape of the surface 45 of the master cam. While this is happening, the wheel 13, having reached point B, has entered the work piece and is now rough grinding the non-circular bore. It does so with a reciprocating motion as the work surface is presented to it through the motions imparted by the master cam surface 45. Rough grinding continues to the point C where an electrical contact in the feed box 14 causes the table to run out, lowering the dressing tool into position. Since the housing 16 has been moved slightly forwardly on the base as a result of the compensating cycle, the dressing tool has partaken of the same movement and, therefore, removes a small amount from the surface of the wheel 13 in a dressing operation. It is well to note that at this point the diameter of the dressed wheel has the same diameter as the mean diameter of the follower 47 which contacts the master cam surface 45. The wheel now re-enters the bore at point E and continues reciprocating and feeding during the finish grind, which is the period between point E and the point P. At the point P the feed is stopped and any further grinding takes place only because of the flexture of the wheel spindle during a spark-out; usually the sparkout period is determined by a timer included in the feed mechanism 14. At the end of the spark-out period, when the workpiece is finished, the table 20 starts to run out to its rest position. At point G an electric switch is actuated, cutting off the power to the workhead motor 17 and de-energizing the solenoid of a brake on the motor shaft, thus causing the workhead to stop. As the table arrives at point H, the compensation cycle is again initiated for grinding the next piece.

While certain novel features of the invention have been shown and described and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without depatring from the spirit of the invention.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent l. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a ring mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel, means for rotating the ring, means for mounting a workpiece on a side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, and means to bring about the said longitudinal movement of the follower to compensate for reduction of wheel diameter.

2. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a wheelhead housing mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke being capable of lateral sliding movement relative to the housing, means for mounting the workpiece on a side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the cam is continuously pressed against the follower, and means to bring about the said longitudinal movement of the follower to compensate for reduction of wheel diameter.

3. A cam grinding machine, comprising .a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, the yoke being capable of lateral sliding movement relative to the housing, means for mounting a workpiece on a side of a ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, means to bring about the said longitudinal movement of the follower to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

4. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral feeding movement only, means to bring about relative lateral feeding movement between the workhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke also being capable of lateral sliding movement relative to the housing, means for mounting a workpiece on the side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, and means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter.

5. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slidehead, means for mounting a workpiece on a side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of the lateral movement so that the master cam is continuously pressed against the follower, and means to bring about the said longitudinal movement of the follower to compensate for wheel diameter.

6. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slide head, means for mounting a workpiece on a side of the slide head facing the wheel head, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, means to bring about the said longitudinal movement of the follower to compensate for wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

7. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slide head, means for mounting a workpiece on a side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, and means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter.

8. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke being capable of lateral movement relative to the housing, means for mounting a workpiece on a side of the ring facing the wheel, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, means to bring about the said longitudinal movement of the follower to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

9. A carn grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke being capable of lateral sliding movement relative to the housing, means for mounting a workpiece on a side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, and means to bring about the said longitudinal movement of the follower so that the average point of contact with 19 the surface of the master cam is moved laterally to own pensate for reduction of wheel diameter.

10. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke being capable of relative sliding movement relative to the housing, means for mounting a workpiece on a side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing a follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

11. A carn grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the aXis of the wheel; means for rotating the journal of the slide head, the slide head also being capable of lateral sliding movement relative to the housing, means for mounting a workpiece on a side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, means to bring about the said longitudinal movement of the follower to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

12. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slide head, means for mounting a workpiece on a side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, and means to bring about the said longitudinal movement of the follower so that the average point of contact with the 11 surface of the master cam is moved laterally to compensate for a reduction of wheel diameter.

13. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a yoke and a ring mounted in the housing, the ring being mounted in the yoke for rotation about an axis parallel to the axis of the wheel, means for rotating the ring, the yoke being capable of lateral sliding movement relative to the housing, means for mounting a workpiece on a side of the ring facing the wheelhead, a master cam mounted on a side of the ring facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

14. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head comprising a yoke having horizontal journals slidably mounted in the housing for horizontal movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slide head; means for mounting a workpiece on the side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

15. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of movement only, a journal mounted in the yoke for rotation only relative thereto about an axis parallel to the axis of the wheel; means for rotating the journal of the slide head, means for mounting a workpiece on the side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the wheel, a cylinder connected to the yoke to continuously press it in one direction of lateral movement so that the master cam is continuously pressed against the follower, means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

16. A grinding machine for finishing a cam with an abrasive wheel, comprising a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base for movement perpendicular to the wheel axis, a truing too'l mounted on the housing, a feed mechanism to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base for movement parallel to the wheel axis, a slide head mounted in the housing for rotation about an axis of the wheel, the slide head having journals and a power cylinder to cause a biased lateral sliding movement relative to the workhead, means for mounting a master cam on the slide head, the follower and master cam having engaging conical surfaces, a piston actuating a ratchet and pawl mechanism, the said mechanism rotating a screw and nut mechanism to bring about the said parallel movement of the follower to cause the master cam to engage a laterally-displaced portion of the follower to compensate for reduction of wheel diameter, and a key and inclined slot connection between the follower and the housing to move the housing and truing tool laterally during the longitudinal movement of the follower.

17. A grinding machine for finishing a cam with an abrasive wheel, comprising a base, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base, a yoke mounted in the housing and capable of lateral sliding movement only relative thereto, a ring mounted in the yoke for rotation relative thereto, a master cam mounted on one side of the ring for engagement with the follower, a hydraulically-activated workpiece-holding means on the other side of the ring, the yoke having diametrically opposed journals which reside in sliding relationship in recesses formed in the housing, a first hydraulic passage extending through the housing into one of the recesses, a second passage in the corresponding journal communicating at one end with the first passage, and a groove formed in the surface of the ring leading to the workpiece-holding means and in continual communication with the other end of the second passage.

18. A grinding machine for finishing a cam with an abrasive wheel, comprising a base, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a workhead housing mounted on the base, means to bring about relative feeding movement between the wheelhead and the housing, a follower mounted on the base, a yoke mounted in the housing and capable of lateral sliding movement only relative thereto, a ring mounted in the yoke for rotation relative thereto, a master cam mounted on one side of the ring for engagement with the follower, a hydraulically-activated workpiece-holding means on the other side of the ring, the yoke having diametrically opposed journals which reside in sliding relationship in recesses formed in the housing, the workpiece-holding means having a clamping piston, a first hydraulic passage extending through the ring, communicating at one end with one side of the said piston, and terminating at the other end in the outer periphery of the ring, a second hydraulic passage extending through the ring, communicating at one end with the other side of the piston, and terminating at its other end in the outer periphery of the ring, the first and second passages being located at axially-spaced positions on the ring, the passages opening into corresponding annular grooves formed in the yoke, a third passage extending through one of the yoke journals and opening at one end into one of the grooves, a fourth passage extending through the other journal and opening at one end into the other groove, and means for selectively connecting the third and fourth passages to hydraulic pressure and drain to move the clamping piston in one direction or the other.

19. A cam grinding machine, comprising a base, an abrasive wheel, a wheelhead carrying the wheel and mounted on the base for movement in the direction of the wheel axis, a Workhead housing mounted on the base for lateral movement only, a truing tool fastened to the housing, means to bring about relative lateral feeding movement between the wheelhead and the housing, a follower mounted on the base for longitudinal movement only, a slide head slidably mounted in the housing for horizontal movement and mounted for rotation about an axis parallel to the axis of the wheel, means for rotating the slide head, means for mounting a workpiece on the side of the slide head facing the wheelhead, a master cam mounted on a side of the slide head facing the follower, the follower and master cam having engaging conical surfaces which are inclined to the axis of the Wheel, means to bring about the said longitudinal movement of the follower so that the average point of contact with the surface of the master cam is moved laterally to compensate for reduction of wheel diameter, and means associated with the follower to move the said housing and truing tool laterally when the longitudinal movement of the follower takes place.

20. A cam grinding machine, comprising a base, an abrasive Wheel, a wheelhead carying the wheel and mounted on the base for movement in the direction of the wheel axis, a Workhead mounted on the base, a truing tol mounted on the base for lateral movement only, means to bring about relative lateral feeding movement between the wheelhead and the workhead, a follower mounted on the base for longitudinal movement only, a slide head slidably mounted in the workhead for horizontal movement and mounted for rotation about an axis parallel to the axis of the wheel, means for rotating the slide head, means for mounting a workpiece on the side of the slide ead facing the Wheelhead, master cam mounted on a side of the slide head facing the follower, one of the follower and master cam having a conical surface which is inclined to the axis of the wheel, means to bring about the said longitudinal movement of the follower so that the point of contact with the surface of the master cam is moved laterally to compensate for reduction in wheel diameter, and means associated with the follower to move the truing tool laterally when the longitudinal movement of the follower takes place.

References Cited in the file of this patent UNITED STATES PATENTS 2,583,363 Durland Jan. 22, 1952 2,592,875 Durland Apr. 15, 1952 2,701,432 Kent Feb. 8, 1955 2,723,499 Dix Nov. 15, 1955 FOREIGN PATENTS 159,602 Sweden July 9, 1957