US1234771A - Mechanical movement. - Google Patents

Description

J. KIEWICZ.

MECHANICAL MOVEMENT. APPLICATION mm NOV. 16. 1915.

Patented July 31, 1917.

\nvenfor. John Kiewicg.

b a wzwxw Atty's.

I) H/ & 9

UNITED STATES PAT NT OFFICE.

JOHN xmwrcz, or BOSTON, MASSACHUSETTS, assreNon TO THE REEGE BUTTONHOLE MACHINE coMPANY, ,or BOSTON, MASSACHUSETTS, A CORPORATION or MAINE.

MECHANICAL MovEMEN'r. j

' Specification of Letters Patent. I Patented July 31, 1917.

Application filed November 16, 1915. Seria1No.-61,831.

rotary motion into an intermittent or vari A- mechanical moveable rotary motion. ment operating in this way is capable of a wide variety of uses, among which maybe mentioned as an illustration, the operation of a feed cam for a sewing machine.

In many types of sewing machines the work is fed by means of a rotary feed cam,

and it is desirable that the feed should be intermittent so that the feeding movement will occur when the needle is withdrawn from the goods and the work will be at rest when the needle is penetrating the goods.

-My invention is adapted for use not only in giving intermittent rotary movement to the feed cam of a sewing machine, but is also capable of use in various other devlces where an intermittent or variable rotary motion is desired. Hence the above reference to the sewing machine is merely for the purposes of illustration and not for the purpose of limiting the use to which the in vention may be put.

One familiar way of converting a continuous rotary motion of a driving element into an intermittent rotary motion of a driven element is by means of a pawl-and-ratchet mechanismwhich derives its operation from the continuously-rotating driving element. While a pawl-and-ratchet mechanism may work satisfactorily where the machine is operating at a comparatively low speed, yet where the demands of use require high speed operation a pawl-and-ratchet is not always satisfactory because sometimes when the driven element is stepped forward by the operation of the ratchet, themomentum of the element will carry it beyond the desired point, thus giving it a longer step than was intended.

It is one of the objects of my present invention to provide a novel mechanism for converting continuous rotary movement into intermittent or variable rotary movement which is positive in its action and which insures the correct stepping forward of the driven element at each operationeven when the device is being operated under .high

speed conditions. I secure this end by con- 4 necting the driving and driven elements with gearing which is positive in its action, and by providing means whereby the rotative effect of the gear is partially or entirely nullified during one period of the cycle of operations and is then an ented during another period of the cycle 0 -opera-' tions with the result that the driven element will be given the intermittent or variable motion in a positive manner and Without any back-lash or-loose play, such as is liable to be found in a device where a pawland-ratchet is used for this purpose.

In order to give an understanding of my invention, I have illustrated in the drawingfis a simple embodiment thereof which is en cient to give an understanding of the principle, but I wish it understood-that the device shown in the drawings is illustrative only and that the invention is not. limited to the construction shown. 4

Figure 1 of the drawings is a plan view showlng a mechanical my invention;

Fig. 2 is a section on the line 22, Fig. 1.

I.have shown at 1 the driven element of the device which is in the form of a rotary member pivotallymounted to rotate about a movement embodying,

stud or shaft 2. This driven element 1 re- I ceives its motion from a shaft 3 through suitable gearing which in the present 'embodimentof the invention' comprises a worm 4: on the shaft 3 meshing'with worm-teeth 5 formed on the driven element 1.

If the worm 4 were fast on the shaft 3 then, of course, the element 1 would rotate I uniformly with the shaft 3.

My invention includes means whereby during a certain part of therevolution of the shaft 3 the rotative effect of the'worm4 on the element 1' is partially or entirely nullified, while during the next succeeding part of said revolution of'the shaft 3 the rotative effect of the worm 4 on the part 1 is augmented. This successive nullification and augmentation of the rotative effect of the worm 4 on the shaft will result in giving to the element 1 either an intermittent rotary or a variable rotary movement, dependin on the particular construction employed. I

secure this alternate nullification and augmentation of the rotative effect of the worm 4 on the element 1 by mounting the worm 4 on the shaft 3 so that it can move longitudinally thereon but must rotate therewith. If, for instance, the worm 4 is being moved longitudinally toward the right, Fig. 1, on the shaft 3, at the same time that the shaft is turning in the direction of the arrow a,

Fig. 1, the resultant motion which is given to the element 1 is the combined effect of the rotation of the worm 4 and its longitudinal movement, both of which tend to turn the element 1 in the direction of the arrow 1). On the other hand, if the worm 4 is being moved toward the left, Fig. 1, while the shaft 3 rotates in the direction of the arrow at, this movement to the left will nullify or partially nullify the motion given to the element 1 by the rotation of the worm 4. If the extent of the longitudinal movement of the worm 4 toward the left Fig. 1 during the time that the shaft 3 rotates through a predetermined angle has the proper relation to the speed of rotation of the shaft, such longitudinal movement will completely nullify the action of the worm 4 in rotating the element 1, and as a result said element will merely remain stationary. Therefore, by ving the worm 4 a vibratory movement longitudinally of the shaft 3 while the latter is rotating, it is possible to vary the rotation of the driven element 1 so as to give it an intermittent 1 otary movement.

If the shaft 3 is rotating uniformly, the particular character of the oscillating motion which the element 1 has will depend upon the relation between the vibratory movement of the worm 4 and the rotation of the shaft 3, and it would be possible to make this relation such that the driven element 1 will be given a quick step forward, then a slow step forward, then a quick step forward, and a slow step forward, etc., or to give the element 1 a step forward, a short step backward, a second step forward, a third step backward, etc., as well as to give it the intermittent motion.

The worm 4 may be mounted on the shaft 3 in any suitable way which will permit of its being moved longitudinally of the shaft.

In the construction herein shown the worm is provided with a hub 6 having one or more slots therein, said slots receiving rolls 8 carried by a pin or stud 9 extending from the shaft 3. This permits the worm 4 to have the movement lon itudinally of the shaft while at the same time compelling the worm to rotate uniformly with the shaft. Any other connection between the worm and the shaft which will permit of this operation may be employed, however, without departing from my invention.

The shaft 3 is shown as mounted in bearings 10, but may be sustained in any suitable way. Said shaft may also be given its ment 1 forwardly,

rotary movement by any desired means. In the construction shown, said shaft 3 is driven from a shaft 11 by means of bevel gears 12, 13 and the shaft 11 is shown as having a pulley 14 thereon by which it is operated from some suitable source of power. This particular arrangement, however, may be varied without departing from the invention, as the particular driving mechanism for the shaft 3 will depend largely upon the machine or other elements with which this mechanical movement is 23 operating in a groove 24 formed in a' hub portion 22 of the worm 4. The cam groove 16 is so constructed as to give the elbow-lever 17 an oscillating movement about its pivot as the shaft 11 rotates, and this oscillating movement results in vibrating the worm 4 back and forth on the shaft 3. The particular relation between the vibratory movement of the worm 4 and the rotation of the shaft 3 will, of course, depend upon the character of the cam 16, and this will be varied to suit the requirements of use. If it is desired to give the driven element 1 an intermittent motion, then the cam groove 16 will be so designed that when the roll is passing from the portion 20 of the cam groove to the position shown in Fig. 1, the worm 4 at such a speed as to counteract the rotative effect of the worm on the element 1, and the effect will be that of the worm 4 being screwed to the left by the worm gear. "When the roll on the elbow-lever 17 is moving from the position shown in Fig. 1 to the portion 21 of the cam, the worm will be given a movement toward the right Fig. 1. This movement of itself will turn the driven elebut as the worm 4 is rotating while it is being moved longitudinally of the shaft, the oscillating motion given to the element 1 is the combined effect of the rotation of the worm 4 and its movement may also be employed.

will be moved to the left a 511 groove 16 is constructed to give theqlever a n i s t backward movement, while if the throw; the element 1 v will have 5 a. fast forward movement whilefthe cam operated end of the lever 17 ismoving downwardly,

and aslow forward movement while said,

end of the 1ever"17 is moving upwardly...

=It will be' noted that the driving connec l0 non-'1. between the driving element and the driven element is a posltive connection by" which the driven element is at all times held under.- control and yet saidconnection is such-that the desired intermittent or van able movement may be given to. the driven element. The positive vgearing connection between the driving and driven elements insures that all of the forward" steps of the driven element will be of uniform extent 2Q SPGGd OOIlQItIOHS,

theoperatlon of thedrivn-element is proeven when the device is operated under high and thus entire accuracy in videdforli:

I havereferred to the effect on the driven -andretarding the re in'g such movement." By='the term retard? intend to include any action whlch "partlall or; completely counteracts the "rotatiVd e idriven elementl,andl thisfmay be such'as we e at element "1 willibe given ect 'of'the. worm/1 on the" may even beflsuch asto movethe elementl ibackw'ardlyslightly. The particular char-' acter of the-variable motion which is given I to the element 1 is alsodetermined toaf greater or less extent [b the relation ,be:

tween'the speed Iof rota ion .of the shaft 3 While I: have illustrated a selected '-1b,odi ment of my invention, I do not wish to limited to the constructional. features is own. 3

and the movement of the worm 4.-

:I-claim:

1. In a mechanical movement, the combi nation with a rotatalale shaft, of afworm mounted thereon for rotative' movement therewith, but capable of movement longitudinally thereof, "a driven element with whichfsai'dworm meshes; meansv to rotate the shaft, and means actuatedby the rotating means for theshaft to vibrate said worm longitudinally of thes haftas the-latterfrotates and in timed relation with the rotation 2. Ina

"echanioalmovement; the combination with a rotatable shafn of a wormf 'mounted' thereon for rotative zmovementtherewith butcapable of movement lontu-. *dinally thereof, a driven element with w ich said wormmesheaa seeond shaft geared to ated} by said second shaft to vibrate the worm longitudinally-of the first-named shaft'as the IatterrOtateSQj g In te timony whereof,; I have 'signed my a name to,,. this specification. to on1y slowdownftheelement1,,or-may be Y 5 i as to; hold said element-stationary, for

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