US2984950A - Resilient control of master cam - Google Patents

Description

RESILIENT CONTROL OF MASTER CAM Filed Oct. 22, 1958 INVENTOR HAROLD E. BALSIGER ATTORNEY S United States Patent RESILIENT CONTROL OF MASTER CAM Harold E. 'Balsiger, Waynesboro, Pa., assignor to Landis Tool Company, Waynesboro, Pa.

Filed Oct. 22, 1958, Ser. No. 769,023

Claims. (Cl. 51-101) The following is a specification in detail of an invention in resilient control for a master cam. In general the invention relates to an improvement in a machine for grinding cam shafts, where the position of the cam shaft relative to the grinding wheel is varied as required by the shifting of a master cam controlling the approach of the cam shaft to the grinding wheel.

The invention has particular reference to a machine for grinding cam shafts as disclosed in the invention of Balsiger and Price, patented May 27, 1941, No. 2,243,410.

In the patent, the cradle is rocked to separate the master cam and roller by means of a piston operating against a spring. The piston compresses the spring as it passes through the entire movement of separation. The return of the master cam to engagement with the roller is effected entirely by the spring which also returns the p1ston to starting position.

It is therefore an object of this invention to provide means whereby the force of the piston is applied to advance the cradle as well as retract it.

A further object is to provide a resilient connection between said piston and the means for operating the cradle when the master cam is to be moved into engage ment with the follower.

A further object is to provide means whereby spring pressure is not exerted on the cradle arm until after the master cam engages the roller.

It is an object of this invention to provide novel means to effect an unimpeded advance of the master cam into contact with the usual follower roll.

It is a further object of the invention to maintain resilient pressure upon the advancing master cam and furthermore increase that pressure as the master cam is brought into contact with the follower roll.

A still further object of the invention is to provide a movable support for the resilient compression means for applying pressure to the master cam.

Among the objects of the invention is to permit a free retraction of the operating means independent of the pressure applying arm.

Other objects of the invention will be evident from the following description of the preferred form of the invention as illustrated in section in the accompanying drawing.

In brief, the objects of the invention are attained by providing a resilient means actuated by hydraulic or other power means, for applying advancing pressure against the rocker arm controlling the position of the master cam. This resilient means is supported by a movable abutmentso that the full force of the resilient ice means is applied against the rocker arm and in fact increases with the advance of the latter. The resilient means specifically is a compression spring. The compression is supplied by said power means acting through said abutment. This has the characteristic of increasing the pressure only after the master cam engages the follower.

The invention as shown on the accompanying drawing, is embodied in a grinding machine for cam grinders such as is disclosed in the patent above identified and to which reference is made forthe general features of the structure.

Cam grinding machines of this type are provided with a headstock housing 5 mounted upon the carriage 29 of the cam grinding machine.

This headstock housing has a longitudinally extending shaft 6. The shaft 6 carries a follower roll 7.

A pivot shaft 8 also extends longitudinally of the carriage below the follower shaft 6. The .pivot shaft 8 permits cradle 9 to oscillate. freely to the extent indicated by the dotted lines on the drawing.

The cradle 9 has a journalled master shaft 10 for a master cam 11. The master cam 11 and the roller 7 can be brought opposite each other in the same vertical plane so that by rocking the cradle 9, the cam 11 can be brought into contact with the follower roll 7.

The shaft 10 is axially disposed to the workpiece, not illustrated, which it is desired to present to the grinding Wheel of the customary type as shown in the patent to Balsiger and Price, mentioned.

In order to rock the cradle 9 and thus bring the appropriate cam of the workpiece into engagement with the grinding wheel, the cradle 9 is supplied with a rocker arm 12. The upper end of the rocker arm 12 is provided with a recess or depression 13 on one side.

A cylinder 14 is mounted transversely of the housing opposite the head of the rocker arm 12. A piston 15 in the cylinder is provided with a piston rod 16 which extends into the headstock opposite the end of the rocker arm 12. The extent of travel of piston 15 to the right is determined by adjusting screw 26 which abuts against the head 27 of the cylinder at the limit of movement to the right.

The piston rod 16 has a collar 17 upon the inner end.

The opposite side of the carriage has a slide bearing 18 coaxial with the piston rod 16. A cylindrical shell 19 is slidably fitted within the bearing 18. The inner end of the cylinder 19 is attached to the collar 17.

An abutment 21 has a threaded connection with the inner wall of cylindrical shell 19 and has a reduced portion 28 also threaded to receive member 20 which is a lock nut.

The inner end of the shell 19 is cut away as shown on the drawing to provide clearance for the movement of the upper end of the rocker arm 12.

A plunger 22 is fitted slidably into the axial bore of the abutment 21. The inner end of the plunger carries a stop or disk 23 behind an enlarged end 24 of the plunger. A compression spring 25 extends from the abutment 21 to the disk 23.

The drawing illustrates the positions of the parts with the piston 15 in its right-hand position and the cylinder 19 forcing the plunger 22 against the rocker arm 12 under the pressure of the compression spring. The force exerted by spring 25 may be varied by axial adjustment of said At the conclusion of the grinding operation, the fluid pressure in front of the piston 15 is reduced and the pressure applied to the right-hand side of the piston thus causing the piston rod 16 to retract the cylindrical shell 19 and after the compression spring has resumed its relaxed position, the plunger 22 will be withdrawn from the depression 13 in the rocker arm 12.

The result of this movement is to release the pressure on the rocker arm 12. Continued movement of piston 15 brings collar 17 into engagement with arm 12, and causes it to oscillate to the left, thus separating the master cam 11 from the roller 7. During this movement the rocker arm Will be free from any force applied at the upper end. However, as the movement of the piston to the left progresses, the collar 17 will then engage the end of the rocker arm 12 and move it to the left, separating master cam 11 from roller 7.

During this operation, plunger 22 is held in engagement with rocker arm 12 with very light pressure, because the spring 25 is extended to its free length. Even this slight pressure does not resist the retracting movement of the piston.

In the initial engagement of the rocker arm 12 by the plunger 22, the cradle is rocked to the right, but the spring 25 is not under compression. Only after the cradle has progressed until the master cam 11 cont-acts the roller 7 does the spring 25 sufier compression and thus increase the pressure upon the rocker arm 12.

The structure as described above is an effective means for providing an unrestricted advance movement for the master cam against the follower roller and increasing the pressure through a movable advancing support for the actuating means. It also permits free and unrestricted retraction of the operating means at the appropriate time.

The preferred form of the invention has been described, but it may be varied in proportions and materials without departing from the scope of the invention as defined in the following claims.

What I claim is:

1. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said headstock, a roller on said shaft, a pivot bearing on the carriage, a work cradle pivotally mounted on said bearing, a master cam rotatably mounted on the cradle opposite said roller, an arm on the cradle, a fluid operated piston having a piston rod movable toward and from the arm, a longitudinally movable connecting member fixedly mounted on the piston rod, a plunger supported on said member and compression means resiliently urging the plunger towardthe arm.

2. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said headstock, a roller on said shaft, a pivot bearing on the carriage, a work cradle pivotally mounted on saidbearing, a master cam rotatably mounted on the cradle opposite said roller, an arm on the cradle, 21 fluid operated piston having a piston rod movable toward and from the arm, a

cylindrical shell having one end mounted on the piston I ton having a piston rod movable toward and from the arm, a cylindrical shell slidably supported in the headstock with one end mounted on the piston rod, a plunger slidably carried by the opposite end of the shell, and a compression spring in the shell resiliently urging the plunger toward the arm.

4. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported on said headstock, a roller on said shaft, a pivot bearing on the carriage, a work cradle pivotally mounted on said bearing, a master cam rotatably mounted on the cradle opposite said roller, an arm on the cradle, a fluid operated piston having a piston rod movable toward and from the arm, a cylindrical shell having one end mounted on the piston rod, a plunger slidably carried by the opposite end of the shell, an enlarged head on the free end of the plunger, a disk on the plunger behind the head and a compression spring in the shell between the disk and the opposite end of the shell.

5. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said headstock, a roller on said shaft, apivot bearing on the carriage, a work cradle pivotallymounted on said hearing a master cam rotatably mounted on the cradle oppo site said roller, an arm on the cradle, a fluid operated piston having a piston rod movable toward and from the arm, a longitudinally movable connecting member fixedly mounted on said piston rod, a plunger loosely carried by said member with its inner end spaced from the piston rod and compression means resiliently holding the plunger against the arm in a position spaced from the piston rod.

6. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said head stock, a roller on said roller shaft, a pivot bearing on the carriage, a work cradle pivotally supported on said bearing, a master cam rotatably mounted on the cradle opposite said roller, an arm on the cradle, a piston cylinder transversely mounted in the headstock, a piston rod slidably extending from the cylinder in line with said arm, a shell having one end mounted on the piston rod, a plunger slidably carried in the opposite end of the shell on the opposite side of the arm, a stop on the inner end of the plunger, and a compression spring in the shell between its end and the said stop.

7. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said head stock, a roller on said roller shaft, a pivot bearing on the carriage, a work cradle pivotally supported on said bearing, a master cam rotatably mounted on the cradle opposite said roller, an arm on the cradle, a piston cylinder transversely mounted in the headstock, a piston rod slidably extending from the cylinder in line with said arm, a collar on the piston rod, a slidable shell having one end attached to the collar, a plunger slidably carried in the opposite end of the shell, a disk on the inner end of the plunger and a compression spring in the shell between its end and the said disk.

8. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said headstock, a roller rotatably mounted on said shaft, a work cradle pivotally mounted on said carriage, a master cam rotatably mounted on said cradle opposite said roller and having a contour of varying radius, an arm on said cradle, a fluid operated piston movable toward and from said arm, connections between said piston and said arm comprising a sleeve slidably mounted in said headstock, a portion of said sleeve being on the opposite side of said arm opposite said piston, an axially adjustable abutment in said sleeve, a plunger engaging said arm, a compression spring having one end in engagement with said abutment, a connection between said plunger and said spring, said piston, sleeve, abutment, plunger and spring being movable as a unit, said abutment being adjustable whereby to place said spring under a predetermined load when the minimum radius of said master cam is in engagement with said roller.

9. In a cam grinding machine, a work carriage, a headstock on said carriage, a roller shaft supported in said headstock, a roller rotatably mounted on said shaft, a work cradle mounted for transverse movement on said carriage, a master cam rotatably mounted on said cradle opposite said roller, an arm on said cradle, a fluid operated piston movable transversely of said cradle, a plunger also movable transversely of the cradle and against said arm and a resilient connection between said piston and the plunger.

10. In a cam grinding machine, a work carriage, a.

work cradle pivotally mounted on said carriage and adapted to support a workpiece, a master cam rotatably mounted on said cradle, a master cam follower on said carn'age, an operating arm on said cradle, a piston having a piston rod directly engaging the arm when moving in one direction, and resilient means carried by the piston rod for engaging the arm when the rod is moving in the opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 2,?A-3,410 Balsiger et a1 May 27, 1941

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