US2472919A - Mechanical movement - Google Patents

Description

June 14, 1949. R. E. PARIS 2,472,919

MECHANICAL MOVEMENT Original Filed April 21, 1943 2 Sheets-Sheet 2 ATT'ORNEY Patented June 14, 1949 STATE-S FICE MECHANICAL MOVEMENT Original application April 21, 1943, Serial No. 483,877. Di vi" ded and this application March 13, 1946,'Seria;l No. 654,106

1 Claim. ,1 I

This invention relates to a mechaiiicalinovement for generating an exactly eo'ntroued reciprocating motion.

One object of the invention is to provide a mechanism which can be made --to reciprocate a machine part in such a way that its movement in one direction is identical as to rate at all stages, to its movement in the opposite direction.

t is a particular object of the invention to produce a reciprocating motion of a machine part, which has a uniform rate during a givenportion of the movement of the part in 'each direction.

Another object is "to provide a mechanism which will reciprocate a'ma'chin'e part with a uniform rate of movement during a given part of its motion in each direction and with a smooth deceleration and acceleration between said periods of movement-at-a-uniform rate.

Other objects of the invention will be pointed out in the following description and'claim and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a plan view of the mechanism, with parts cut away.

Fig. 2 is a vertical sectional view *on the line '22 of Fig. 1.

Fig. 3 is a diagrammatic developed view of the two cams.

The invention will be illustrated by an embodiment disclosed in my copending application Ser.

No. 483,877, filed April 21, 1943, "now Patent No.

2,398,036, wherein it is used for reciprocating a permutation bar unit controlling a printing mechanism. The present application is a division of said application, Serial No. 483,877.

The reciprocating mechanism embodying the present invention is mounted upon a vertical support comprising two plates 320 and 321 secured by screws 322 to the side frame 50. The plate 32I has screwed into it, and rigidly extending from it, two stationary round bars 323 and 324, the reduced outer ends of which pass through holes in an outer plate 325 and are threaded to receive clamping nuts 326. The outer plate, the round bars, and the vertical supporting plates are thereby united into a rig-id frame. Two shafts 258 and 259 are journaled in bearings 321 and 328 in the plates 320, 32| and 325. These shafts are geared to rotate in opposite directions by intermeshing gears 260 and 261 fixed to them, and take their drive through gear 256 fixed to shaft 259, which meshes with a drive gear 251. The shaft 258 rotates clockwise and the shaft "2-59 counterclockwise. The shafts 258 and 259 "have rigidly mounted upon them cam cylinders 33!! and ESL respectively. For constructional reasons each cam cylinder is built up of three parts, namely, two hub members 332 and 333, fixed to the shaft by pins (not shown), and a central shell 334, attached to the hubs by pins such as 335. The cylinders 3.36 and 33l have machined onto their surfaces two spiroidal cam grooves 336 and 331, which are identical in shape, but are relatively reversed in position, so that the outer end of the cam 335 is like the inner end of the cam 331. The end thrust of the spiroidal cams is taken by inner ball bearings 338 and outer ball bearings 339.

A traveler 349 is rockably and slidably mounted upon .the round bar 323 and has mounted upon two oppositely extendin arms 34! a pair of fol-- lower rollers 342 and 343, which can be engaged alternatively with the respective cams 336 and 331. When the follower 342 is engaged with the cam 336 the traveler moves inward, whereas when the follower 343 is engaged with the cam 331 the traveler moves outward. At the inner end of the traveler, there is a hub 344 having a radial aperture 345 through which extends "afoot 346, which is connected to, or integral with,the machine part to be reciprocated. In the aforesaid copending application this foot extends down from the permutation bar unit. The foot346 extends through the aperture 345 into a longitudinal groove 35!! in the round bar 323. The aperture is shaped to permit relative rocking movement of the traveler hub with respect to the foot 346, while retaining a fixed relation thereto into the direction of the stroke of the traveler. The groove 350 steadies the foot 346 laterally. Above and to the rear of the round bar 323 is a stationary square bar 35l, fixed to :the inner plate 32I and outer plate 325 by screws 352. Upon one side of this square bar is fixedly attached a plate 353, the lower edge of which is positioned for cooperation with a pin 354 extending at an angle upward from the traveler 340. The length of the plate 353 is such that the pin 354 can rock past its ends at the two limit positions of the traveler, but in all intermediate positions will be held on one side of the plate or the other, for the full extent of movement of the traveler. The rocking of the traveler in the limit positions is accomplished by reciprocal inclined surfaces in the bottom of the cam grooves 33-6 and 331, indicated by dash lines 355 and 356, in Fig. 2. This view is taken at the time when th traveler has completed its inward movement and is about to be rocked to move the follower 342 out of the cam 336. A clockwise angular movement of the cam roller 330 through 180 from the position shown will cause the cam surface 355 to raise the follower 342 to the top of the cam channel 336, while a synchronized counterclockwise movement of the cam 355 will allow the cam follower 343 to ride into the bottom Of the cam channel 331. A similar, but reversed, coaction occurs when the traveler reaches the outer limit of its stroke.

Figure 3 is a developed diagram of the cam grooves 336 and 33?. The cams move in opposite directions, as indicated by the arrows Cl and C2. The direction of movement of the traveler-346 (Fig. 1) while the follower 342 is in the cam groove 33? is indicated by the arrow T1; the direction of movement of the traveler while the follower 3&3 is in the cam groove 335 is indicated by the arrow T2. lhe explanation of the diagram will start with the follower 3 52 at 338 (342a) on the cam groove 33?, which may be its position of rest when the machine stops. The traveler is accelerated to its high speed as the follower 342 moves along the cam groove 33'! from 330 to 360 (3422)) which may be 0 of the next machine cycle. From 0 to 234 (3420), the traveler executes a movement of uniform high speed in the direction of the arrow T1. Between 234 and 250 (242d) the traveler decelerates to a stop. At 250 the follower 3 53 is over the entrance of cam groove 333 (at 353d) and the traveler begins to rock. From 250 to 324 (342e, 3 43c), as

the cam grooves 336 and 33'! move synchronously to the right and to the left, respectively, the traveler executes a movement of uniform reduced speed in the reverse direction (arrow T2), being moved by both cams, which have the same uniform pitch and direction. At 324 the cam groove 33! terminates. From 324 to 360 (3431 the follower 353 moves along the cam groove 33S and the speed of the traveler is accelerated in the direction of the arrow T2. At 383, which is also 0 of the next cycle, the traveler begins its uniform high speed movement in the direction of the arrow T2, which continues to 234 (3439). From 234 to 256 (343% the traveler is decelerated to a stop. At this point the traveler begins to rock as the follower 342 enters the cam groove 33'! again (34271). From 250 to 324 (343i, 342i) the traveler moves in the direction T1 at uniform reduced speed, as it rocks to move the follower 343 out of cam groove 335 and the follower 342 into the cam groove 337. From 324 to 360 4 (342b) the traveler is accelerated to full speed in the direction T1.

Summarizing the movements imparted to the traveler by the spiroidal cam grooves in one ma chine cycle, the traveler first executes a movement in one direction at a uniform high speedi for 234 of the cycle, then decelerates to a stop, reverses its direction of movement, and acce1erates to the same high speed in the opposite direction. In the next cycle the sequence is identical but the directions of movement in the corresponding parts of the sequence is reversed.

The invention is not limited to a mechanical movement in which the two cams are identical, so long as the overlapping parts of the cams are reciprocal.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the deviceillustrated and in its operation may be made by those skilled in the art, without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claim.

What is claimed is:

In a mechanical movement, two cylindrical cam members mounted to revolve on parallel axes,

each of said members having a spiroidal cam on its surface, a traveler having cam follower means engageable alternatively with said cams, said cams having middle portions disposed so as to move said traveler in opposite directions and end portions at each end disposed so as to move said traveler in the same direction, and means to move said traveler, while traveling in one of said end portions, so that its follower means are gradually disengaged from one cam member and engaged with the other cam member, and to move said traveler, while traveling in the other of said end portions, so that its follower means are gradually disengaged from said other cam member and engaged with said first cam member.

ROBERT E. PARIS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 591,086 Shakespeare Oct. 5, 1897 2,359,156 Richey et al Sent. 26. 1944

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