US1284884A - Cam-path-generating machine. - Google Patents

Description

` E. E. FOSTER.

CAM PATH GENERATING MACHINE.

AFPucATloN min ocr. 24. 1913.

Patented Nov. 12, 1918.

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. E. E. FOSTER.

f PATH GENERATING MACHINE. APPucATlore mso oc. 24. |913.

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EDWARD E. FOSTER; OF BEVERLY, MASSACHUSETTS.

CAM-PATH-GENERATING MACHNE.

Specification of Letters-Patent. Patented' NOV. 12, 1918.

Application filed October 24, 1913. l Serial-No. 797,080.

To all whom tlm/ay concern.'

Be it known that I, EDWARD E. FOSTER, a citizen ofthe United States,residing at Beverly, in the county of Essex and Stateof Massachusetts', `have invented a new and useful Improvement. in Cam-Path-Grenerating Machines, ofV whichthe following is a specification.

As well known to thoseskilled in the art it is customary in the manufacture of cams to first generate the cam path upon paper and then scratch the outline of the generated cam path upon the leader. The leader is then cut down to the inner working surface of the pathafter which it is inserted in the cam cutting machine where `it directs the operation of the cutting tool. As there are three principal kinds of motion imparted to a follower by a cam, namely, harmonic, uniform andvgravity motions, to generate a cam path so that it will impart the proper motion to a follower including the proper sequence of rises, drops and dwells requires considerable knowledge, experience and skill upon the part of the designer'e'specially as these cani paths are continuous and are each provided with differential drops and rises--thatl is, a cam path having motion sections, the sections havingl different drops or rises., By a gravityfmot'ion cam path I mean acam path that will impart to al follower a uniformly accelerated orv retarded momentum corresponding to the uniformly accelerated or retarded momentum imparted' by gravity to falling and ascending: bodies, respectively. I have discovered that some of the well known mechanical devices are adapted to impart motions corresponding to the harmonic, uniform and gravity motions of cam follower. For instance, a crank inf rotating through1180 degrees impartsiharmonic motion toa driven member, a swinging pendulum has a gravity motion andan inclined plane-imparts to a driveny member equal rises in equal intervals of time or unie form motion. rlherefore, I have conceived the idea of utilizing mechanism inthe gen eration of cam paths. I believe I am the first to have employed mechanism in the generation of .continuous cam paths having motion sections, the sections'having differ ential rises and drops or'times.:`

rPhe object ofthe present invention is to produce. a'machine by which cam paths for imparting any kind ofmotion to an oscillating follower, that is, a follower which moves in ai circular path may be accurately generated by an operativel having little or no training inthe design of cams.

To the accomplishment of this object and such others as may hereinafter appear the featuresof the invention relate to certain devices, combinations and arrangements of parts vhereinafter described and then set forth broadly and in detail in the appended claims which possess advantages which will be' apparent to thoseskilled in the art.

rIhe various featuresof the present invention will behest understood from an inspection of the accompanying drawings illustrating one "embodiment of the invention, in which:

Figure 1 isa perspective, partly in section, of amachine for generating a cam path in a barrel leader for imparting a harmonic motion to afn oscillating follower;

Fig. 2- is a longitudinal sectional elevation of the crank for oscillating the tool;

Fig. 3r is al perspective, partly in section, of a. machine for generating a cam path in a disk leader for imparting a harmonic motion to `an oscillating follower; and

Fig. 4 is a longitudinal sectional elevation of the tool frame and the parts carried thereby.`

In the illustrated embodiment of the invention the cam path isgenerated directly upon the leader by a tool which is rotatedto scribe a circle upon'the leader having a diameter substantially equal to the diameter of the followerv employed with the cam. The leader is rotated to transfer the point of operation of the tool around the leader andthe tool is swung during the rotation of the leader to change the direction of the ,j

path scribed by the tool upon the` leader. The tool isswung -byia crank in the specific formx of the invention selected for the purpose of illustration and consequently a can path -for imparting a harmonic motion tothecamfollower is generated, but, it will be apparent to those skilled inthe art tiat mechanism for swinging the tool with either a uniform or a gravity motion may be substituted. vfor the crank and that the tool may be reciprocatedv insteady of oscillated if it is desirable to' generate a cam path for imparting motion to a reciprocating follower. In order to adaptl the machine for generating any desired cam path adjustments are provided for varying the operation of the tool' in accordance with variations in the lli.)

base circles, rises, drops, dwells and times in the different cams to be designed.

The leader 1 which is preferably a castiron cylinder having a thin deposit of cop.- per upon its peripheral face, is supported by a shaft 2 which is journaled in bearings 3 formed in a frame 4. One end ofthe frame 4 is integrally connected to a slide 5 which is mounted to slide vertically upon ways 6 formed inthe machine frame. The other end of the frame 4 is loosely mounted on a vertical shaft 7 the upper endof which is journaled in a boss 8 suitably bored in a table 9 carried by legs (not shown), and the lower end of which is journaled in a bearing 10 carried by a sleeve 11 loosely mounted on a horizontal shaft 12 j ournaled in bearings depending from the table 9. ln order to permit the easy insertion of the shaft 2 into the machine and its withdrawal therefrom the bearings 3 are made in sections, the lower half being stationary and the upper half being pivoted to the frame 4. The halves of the bearings 3 are clamped together by a bolt 13 which is pivoted to the stationary half of the bearing. l/Vith this construction when it is desired to remove the shaft 2 the heads of the bolts 13 are loosened and the bolts are then swung downwardly out of clamping position thereby permitting the pivoted halves of the bearings to be swung upwardly and turned over upon the top of the frame 4 thus permitting the shaft 2 to be lifted out of the machine. When the shaft 2 is` replaced the pivoted halves of the bearings are swung downwardly over the shaft then the bolts 13 are swung upwardly into clamping position and the bolt heads turned to clamp the halves of the bearing together. To bring the upper face of the leader into the operating plane the, slide 5 is raised or lowered as re-v quired and is then clamped in adjusted position by a pair of clamps 14 arranged to bind the slide 5 on t-he ways 6.

The leader 1 is rotated during the operation of the machine through a pair of bevel gears 15 one of which is carried by the shaft 2' and the other one of which is removably splined to the shaft 7. The shaft 7 also carries a bevel gear 16 which meshes with a gear 17 carried by the shaft 12 and also with a bevel gear 1S which is carried by a sleeve 19 loosely mounted on the shaft 12. Secured to the sleeve 19 is a disk 2O which is provided with a scale 21 on its periphery cooperating with. a pointer 22 secured to an overhanging bracket 23 projecting from the table 9. The scale 21 is Lgraduated in degrecs from O to 360 and the gears 15, 16, 17, and 18 are proportioned to impart a complete rotation to the leader when the disk 20 is rotated to transfer the pointer 22 entirely around the periphery of the disk'20. Splined to the shaft 12 is a second disk 24.

The back faces of the disks 20'and 24 rotate in engagement with rolls (only one of which is shown) 25 which hold the disks pressed toward each other.

ln order to scratch the cam path upon the `leader the machine is provided with a scratching tool 26 (Fig. 4) which is held by a screw 27 in a block 28 carried by a carrier 29. The carrier 29 is secured to a sheave 30 carried by the lower end of a vertical shaft 31 which is rotatably mounted in a chamber 32 formed in a frame 33. The frame 33 is secured by a clamping bolt 34 to a horizontal plate35 which is guided to slide radially of the shaft 7 by a rod 36 which passes loosely through a slot 37 formed in the plate. The rod 36 is mounted axially of the shaft 7 and may rotate in bearings 33 carried by the bracket 23. The sheave 30 isdriven from some suitable source of power so that the tool may be rapidly driven to scratch al circle upon the face of the leader and thus form a closed cam path upon the eader. As the diameter of this circle is substantially equal to the width of the cam path or the diameter of the cam follower provision is made for adjusting the tool to scratch different sizes ofreircles in accordance with the different widths of the'cam paths to be generated. To this end the block 28 may 'be adjusted in ways formed on the carrier 29 in' a path transverse to the aXis of rotation of the shaft 31. With this construction the tool 26 may be actuated to form a point upon the leader when the tool is adjusted in line with the axis of the shaft 31 orpmay be actuated to scratch a circle having a diameter equal to the length of the carrier 29 when the tool is placed at one end of the carrier. To serve as a guide for the adjustment 'of thev block 28 on the carrier 29 the carrier is provided with an index 39. The adjusted position of the tool 26 on the carrier 29 is maintained by a clamping screw 40 arranged to bind the block 28 on the ways of the carrier 29. The tool 26 is pressed against the face of the leader by a spring 41 which is interposed between the top of the shaft 31 and the end of the chamber 32. In order to elevate the tool 26 against the tension of the spring 41 the frame 33 carries a horizontal shaft 42 one end of which is provided with a knurled knob 43 and the other end of which carries an eccentrically mounted pin 44 arranged to engage a groove 45 on the shaft 31. With this construction a turn of the knob 43 elevates the tool from the face of the leader. To hold the tool elevated the frame 33 carries a spring-pressed plunger 45X which engages a groove 46 formed in the shaft 42.

lVith the construction so far described a rotation of the leader will transfer the point of operation of the tool around the leader. In order to shift the point of operation of the tool during the rotation of the leader so as tochange the direction of its path the plate 35 is provided with a rack47 which is engaged by a segment 48 carried by'a yoke 49 secured to the rod 36. The segment 48 meshes with a. cylindrical rack 50 loosely mounted on the rod 36 which meshes in turn with a segment 51 journaled on thezbracket 23. The segment 51 meshes with a rack 52 which is secured by a screw 52a to a rod 53 mounted to reciprocate in the bracket 23. The rod 53 is connected to a yokev54 mounted to slide upon guide rods 55 carried :by the bracket 23. The yoke 54 embraces an elliptical block 56 (Fig. 2) which is swiveled upon a crank pin 57 slidably mounted in a slot 58 formed in a platform l59. The platform 59 is secured to the upper end of a vertical shaft 60 the upper endof which is journaled in a bearing carried by the bracket 23 and the lower end of which is journaled in a step bearing 61 carried by the shaft 12. The crank pin 57 is mounted on a second block 62 which slides in ways 63 formed in the platform 59. To hold the block 62 and the parts carried thereby in any desired position of adjustment, it carries a bolt 64 by mea-ns of which the crank pin 57 and block 62 may be clamped to each other and to the platform 59. Vith this construction the tool 26 is reciprocated transversely of the leader by a. crank which is driven by the rotation of the shaft 60. As it is desirable to vary the throw of the crank the upper face of the platform 59 is provided with an index 65 to serve as a guide to the operative in adjusting the yoke 54 nearer to or farther from the aXis of the shaft 60.

In order to produce a cam path which will impart motion to an oscillatingfollo-wer the tool 26 is const-rained during its transfer around the leader to move transversely in the arc of a circle. To this end the plate 35 is connected by a pivo-t 66 to one end of a radius bar 67 the other end of which is slidably connected to a block 68 which is pivoted at 69 on a slide 7 0 carried by a bar 71 one end of which is connected to a protractor 72 carried by the table 9 and the other end of which loosely embraces the vertical rod 36. To facilitate the adjustment the radius bar 67 is provided with a scale 73 associated with an indicator 74 on the block 6r. rI`he radius bar 67 and block 68 are clamped in adjusted position by a clamp 75 arranged to bind the bar 67 on the ways of the block 68.

In designing a machine the first step taken by the designer is to lay off intersecting horizontal and vertical lines which are called the horizontal and vertical lines of the machine. In order to adjust the pivot 69 relatively to the horizontal and vertical lines of the machine so that the pivot 69 may bear the same relation to the leader as the pivot for the cam follower link bears to the cam the slide may be adjusted .along the bar 71 and the bar 71 may be adjusted over the protractor 72. The bar 71 and protractor 72 are provided with indices to facilitate the adjustment. The slide 70 and the bar 71 are clamped in adjusted positio-n by clamps 76 and 77 carried by the slide 70 and bar 71 respectively.

In order to simultaneously rotate the leader 1 and shift the point of operation of the tool transversely of the leader the shaft 60 `carries a'roll 78 the periphery of which engages the opposed faces of the disks 20 and 24. The roll 78 is splined to the shaft 60 and maybe adjusted thereon to position the `roll at any desired .distance between the axes of the disks and the periphery thereof to vary t-he speed of rotation of the shaft 60. To this end the roll 78 carries a ring 79 which rotates upon an arm 80 loosely embracing the shaft 60 and projecting from a clamp 81 which is mounted on a vertical rod 82 carried by the bracket 23 and the bearing 61. A rod 82 is provided with a scale to serve as a guide for the adjustment of the roll along the shaft 60 by the operative. Vith this construction when the operative rotates the disk 20 in the direction of the arrow (Fig. 1) the leader and tool are simultaneously actuated to generate a cam path.

In using the machine to generate a cam path intended to impartl for instance, a harmonic rise of 2 inches in 90 degrees, a harmonic drop of 2 inches in 45 degrees, and a dwell during the remaining angle, the frame 33 is adjusted upon the plate 35 sothat the distancef-.rom :the center of thev shaft 31 to one longitudinal edge of the leader corresponds to the base circle of the cam path to 'be generated. The plate 35 is provided with' a scale to serve as a guide for the operative in adjusting the tool for the base circles. After this adjustment is made the screw 52ais loosened to free the rod 53 from the rack 52 and the yoke 54 is then adjusted along the platform 59 until the axis of the swiveled block 56 is one inch from the axis of the shaft 60. This adjustment is made when the platform 59 is positioned so that a mark 83 thereon registers with a mark 84 on the Lipper face of the bracket at which time the crank is at its limit of movei'nent in one direction. After this adjustment is made the rod 53 is clamped to the rack Now it being desired to generate a cam path for imparting to a cam follower a harmonic rise roll 7 8 is adjusted on the shaft 60 to such a point that when the disk 20 is rotated to transfer the pointer 22 from the 0 mark to the 90 mark on the scale 21 the roll 7 8 will rotate one half a revolution and thus rotate the crank from its limit of movement in of 2 inches in 90 degrees thev one direction to its limit of movement in the other direction. The parts being adjusted as described, the operative rotates the disk 2() until the pointer 22 reaches the 90 mark on the scale 21. During the rotation of the disk 20 the leader rotatesvthrough 90 degrees and the rotating tool 26 is reciprocated away from 'the edge of the leader thus generating upon the leader a cam path which will impart toy an oscillating cam follower a harmonic rise of 2 inches in 90 degrees. To obtain a harmonic drop of 2 inches in the next 45 degrees the roll 78 is adjusted to the 45 mark on the rod 82 so that the roll will again revolve a half rotation as the pointer travels-from the 90 markto the 135 mark on the scale 21. Then the disk is again rotated until the 135 mark is reached. During this movement of the disk 20 a cam path is generated on the leader which will impart to a cam follower a harmonic drop of 2 inches in 45 degrees. To obtain a. dwell. during the ren'iaining angle of 225 degrees the axis of the block 56 may be brought in line 'with the axis of the shaft GO so 'that during the continued rotation of the disk 20 to bring the pointer 22 back to O or, stated in another way, to complete the 360 degree rotation of the leader thel tool'does not travel upon the leader. It is preferred, however, to unclamp the rod 53 from the rack 52 in order to prevent accidental displacement of the tool.

lNhen it is desired to generate a cam path upon a leader for a disk cam a disk 83 is clamped to the upper end of the shaft T (Fig. After the proper adjustments are made for the base circle, rises, drops and dwells the disk 20 is rotated as hereinbefore described and the cam path generated upon the upper face of the leader. As clearly shown in Fig. 2 the tool may be shifted relatively to the pivotal connection between the radius bar 67 and the plate 35 so 4that the tool may scratch a cam path either larger or smaller than the actual cam path desired.

l/Vhile the machine has been described as generating a specific cam path it will be readily apparent. to those skilled in the art that the machine is adapted to generate any cam path for imparting to an oscillating cam follower either a harmonic motion or a dwell as the machine is provided with the necessary adjustment for varying the operation of thc tool upon the leader in accordance with the variations in the base circles, rises, drops and times of the cam paths which it may be desired to generate.

lVhile the invention has been illustrated and described in connection with a machine for generating a cam path for imparting harmonic motion to an oscillating follower it must be understood that this is merely one embodiment of the invention which may have a variety of forms depending upon the kind of motion which it is desired to impart to a follower, the kind of cam to be provided with a cam path, and whether the follower is offset or reciprocates or oscillates. Neither is the specific Construction and arrangement of parts shown and described essential nor is the conjoint use of all the features of the invention essential, except so far as specified in the appended claims, and it may be varied or modified without departing from the broader features of the invention.

ln the following claims the term rises for convenience has been used to denote either rises7 or drops7 or both.

What is claimed as new is:

l. A cam path generating machine, havW ing, in combination, a leader support, a tool, means for generating a cam path for imparting motion to an oscillating follower upon the leader comprising mechanism for actuating the leader' to transfer the point of operaf ion of the tool around the leader, mechanism for moving the tool transversely during its transfer to change the direction of its path, mechanism for constraining the tool to move transversely in the arc of a circle, and mechanism embodied in the machine for varying the transverse movement of the tool in accordance with the variations in the times of the various portions of the cam path.

2. A cam path-generating machine, having, in combination, a support for a barrel leader, a tool, means for generating a cam pathv upon the peripheral face of the leader comprising mechanism for relatively actuating the leader and the tool to transfer the point of operation of the tool around the leader, and mechanism embodied in the machine for varying the position of the tool with relation tov the leader during the transfer of the tool around the leader in accordance with variations in the times of the various portions of the cam path, substantially as described.

3. A cam path generating machine, having. in combination, a support for a barrel leader, a tool, means for generating a cam path upon the peripheral face ofthe leader comprising mechanism for relatively actuating the leader and the tool to transfer the point of operation of the tool around the leader and mechanism embodied in the machine for varying the position of the tool witlrf relation to the leader during the transfer of the tool around the leader in accordance with variations'in the rises and times of the various portions of the cam path, substantially as described.

4. A cam path generating machine, having, in combination, a support for a barrel leader, a tool, means for generating a harmonic motion cam path upon the peripheral face .of the leader comprising mechanism for relatively actuating the leader and the tool to transfer the point of operation of the tool around the leader', and mechanism embodied in the machine for varying the position of the tool With relation to the leader during the transfer' of the tool around the leader in accordance With variations in the times of the various portions of the cam path, substantially as described.

5. A cam path generating machine, having, in combination, a support for a barrel leader, a tool, means for generating a harnonic motion cam path upon the peripheral face of the leader comprising mechanism for relatively actuating the leader and the tool to transfer the point of operation of the tool around the leader, and mechanism embodied in the machine for varying the position of the tool with relation to the leader during the transfer of the tool around the leader in accordance With variations in the rises and times of the various portions of the cam path, substantially as described.

6. A cam path generating machine, having, in combination, a. support for a barrel leader, a tool, means for rotating the leader to transfer the point of operation of the tool along the peripheral face of the leader, means for actuating the tool transversely of the leader during its transfer along the peripheral face of the leader to change the direction of its path, and mechanism embodied in the machine for varying the transverse movement of the tool in accordance With variations in the times of the various portions of the cam path, substantially as described.

7 A cam path generating machine, having, in combination, a support for a barrel leader, a tool, means for rotating the leader to transfer the point of operation of the tool along the peripheral face of the leader, means for actuating the tool transversely of the leader during its transfer along the peripheral face of the leader to change the direction of its path, and mechanism embodied in the machine for varying the transverse movement of the tool in accordance with variations in the rises and times of the various portions of the cam path, substantially as described.

8. A cam path generating machine, having, in combination, a tool rotatable about a vertical axis, a leader support rotatable about a horizontal axis, and means permitting the vertical adjustment of the support,

substantially as described.

9. A cam path generating machine, hav- Copies of this patent may be obtained for ing, in combination, a tool rotatable about a vertical axis, a horizontal shaft for supporting the leader, a frame in Which the shaft is journaled, a slide therefor, and means permitting the slide to be adjusted in a vertical plane, substantially as described.

l0. A cam path generating machine, having, in combination, a leader support, a tool, means for actuatin the leader to transfer the point ,of operation of the tool over the leader, and means for swinging the tool transversely during its transfer comprising a pair of reciprocating racks, a pair of segments meshing respectively therewith, and cylindrical rack engaged by both segments constructed and arranged to rotate and slide longitudinally, substantially as described.

11. A cam path generating machine, having, in combination, a leader support, a tool, means to rotate the tool about a vertical axis, means to rotate the leader support about a horizontal axis, means for relatively actuating the leader and the tool to generate a cam path upon the leader, and means for adjusting the tool with respect to its axis of rotation to generate a cam path differing in size from the actual cam path desired to be formed in the cam, substantially as described.

l2. A cam path generating machine, having, in combination, a support for a barrel leader, a tool for scratching the peripheral surface of the leader, means for impartv ing rapid circulatory movements of slight amplitude to the tool and mechanism for imparting additional relative movements to the leader and tool to transfer the point Vof operation of the tool around the leader,

EDWARD E. FOSTER.

Witnesses CHARLES E. GRUSH, ELMER B. GRUSH.

five cents each, by addressing the Commissioner of Patents,

Washington, D. C.

Itis hereby certiiied that in Letters Patent No. 1,284,884, granted November 12, 1918, upon the application of Edward E. Foster, of Beverly, Massachusetts,

for an improvement in Cain-Path-Generating Machines, an error appears in the printed specification requiringl correction as follows; Page 3,1ine 51, after .the period insert the sentence- To permit the length of the radius bar 67 between the pivots 66 and 69 to he varied in accordance with rvariations in the lengths of the levers which carry the follower to be actuated by the cam paths generated by the machine-0jl the drawings the radius bar 67 is slidablg mounted in wa'ysformed in the block 68.;

and that the said Letters Patent should be read With this correction therein that the same may conform to the record of the casein the Patent ffice. p

Signed and sealed this 11th day of March, A.. D., 1919.

R. F. VVHITEHEAD,

Acting Commissioner of Patents.

[SEAL]

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