US2830456A - Periodic mechanism - Google Patents

Description

April 15; 1958 A. w. STAFFORD P2310510 MECHANISM Filed Jan. 5, 195a 3 Sheets-Sheet 1 I mm M 5:1 wax/7 74% April 15, 1958 A. w. STAFFORD 2,830,456

I PERIODIC MECHANISM Filed Jan. 5. 1956 3 Sheets-Sheet 2 April 15, 1958 A. w. STAFFORD. 2,830,456

PERIODIC MECHANISM Filed Jan. 5. 1956 Inwmfw 3 Sheets-Sheet 3 fllfd Maw/2% var/a) United States Patentb PERIODIC MECHANISM Alec Walter Statford, Stretford, England, assignor to T. M. M. (Research) Limited, Oldham, England The invention has reference to mechanism for imparting periodic motion to a machine part, such mechanism being of the type in which the motion is derived from a rotating cam, and its object is to provide in such mechanism means for bringing about a temporary acceleration (with subsequent deceleration) during each stroke of the periodically moving part.

An example of the type of mechanism to which the invention is applicable is found in the traverse mechanism of a textile spinning, twisting or winding machine, by which the operation of building the wound material into a package of desired shape is achieved by the periodic movement of the guide by which the material is led to the winding point. In certain of such machines it is desirable during the period of reversal of the said guide to accelerate the motion of the guide in such manner as temporarily to alter the helix angle of the wound material, in order to assist in building a package of the desired shape, and this effect can be attained by the use of mechanism modified as hereinafter described.

In mechanism of the said type, according to the invention, the cam motion is transmitted through the medium of a link to which periodic motion is applied by the cooperation with the cam of one cam-follower, the character of such periodic motion being modified by the cooperation with said cam of a second cam-follower. The effect of such modification by the second cam-follower is to accelerate the motion of such link.

In the application of the invention to the traverse mechanism of a textile spinning, twisting or winding ma chine, .the invention may be employed to impose -a secondary acceleration upon each stroke of the traverse motion immediately before or after its reversal, resulting in the required alteration of the helix angle of the ma terial which is wound upon the package during such acceleration.

A member through which the cam motion is transmitted may incorporate mountings for two cam-followers in spaced angular relationship relative to the cam, one such cam-follower (hereinafter termed the main cam-follower) being efi'ective to traverse said member to-and-fro, whereby a push-pull connection linked to said member is actuated to produce a main traverse motion, whilst the other cam-follower being operated in advance of or after the main cam-follower is caused to actuate means on said member whereby the motion of said connection is momentarily altered just before or after its reversal by the operation of the main cam-follower.

The manner in which the invention may be carried into effect is hereinafter more fully described with reference to the accompanying drawings, which illustrate a form of cam-operated traverse mechanism which, although it can appropriately be employed in many situations in which the reciprocatory movement of a member is effected by the operation of a rotary cam, has been designed for use in conjunction with the traverse mechanism of a textile winding apparatus. In said drawings 2,830,456 Patented A r. 15, 1958 Fig. l is a front elevation of the cam mechanism and Fig. 2 is an end elevation thereof. Figs. 3 and 4 are fragmentary views, similar to Fig. 2, of two minor modifications, and Figs. 5 and 6 are respective front and side elevations illustrating means, applicable to any of the embodiments illustrated in Figs. 1 to 4, for varying the stroke of the traverse rod. Figs. 7 and 8 are diagrammatic views depicting the traverse mechanism of a textile winding machine to which the invention may be applied.

The apparatus shown in Figs. 7 and .8 comprises a rotating shaft 10 carrying a plurality of friction rollers 11, 11 upon each of which rests a tubular mandrel 12 upon which a yarn or thread is to be wound. The mandrels 12 are supported at their extremities between members (not shown) which permit the mandrels to move away from the rollers 11 in well-known fashion as the diameter of the packages wound upon the mandrels increases. Each yarn or thread, of which one is indicated at 13 in Fig. 8, is delivered to the winding point by an oscillatory guide 14 and the winding operation is effected by the rotation of the mandrels 12 due to their frictional contact with the rollers 11.

Each guide 14 consists of an arm, having at its upper extremity a notch through which the yarn or thread 13 passes, and clipped to a traverse-rod 17 (as shown in Fig. 8), and the motion of said traverse-rod is efiected by a constantlyrotating cam 18 having a peripheral cam track 19 between the spaced walls of which is located a main cam-follower consisting of a bowl 20 carried by a block 21 mounted for rectilinear movement upon slidebars 22 in a direction parallel to the rotary axis of the cam 18. The arrangement is such that as the cam 18 rotates it transmits a reciprocatory motion to said block 21 upon its slide-bars 22. The cam 18 is mounted upon a shaft 23 which, together with the slide-bars 22 is supported upon a base-plate 24.

The reciprocating block 21 is connected to the traverse-rod 17 by means of a connecting rod 25 to a crank 26 fixed'to a short shaft 27 rotatably mounted in said block 21. Said shaft 27 provides a mount for the main cam-follower 20' and also an arm 28 at the free end of which is a pivot for a bowl 29 constituting the auxiliary cam-follower, the axes of the two cam- follower bowls 20, 29 intersecting at the axis of the cam-shaft 23. g

In the modified embodiment shown in Fig. 3, the main and auxiliary cam- followers 20, 29 are carried at the respective ends of an arm 28-1 fixed at'an intermediate point in its length upon a short crank-shaft 27 rotatably mounted in a slidable block 21 such as that described above. In the further modification shown in Fig. 4, the cam-follower 20 is carried by the end of the crank-shaft 27, and the other is mounted upon an off-set 282 which is keyed on the crank-shaft 27.

In all three of the afore-described embodiments of the invention, the auxiliary cam-follower bowl follows or precedes the main cam-follower bowl 20 in the track 19 of the cam 18 by a short distance, and the arrangement is such that since the auxiliary bowl 29 reaches and passes the reversal point 191 of the cam track 19 after or in advance of the main bowl 20, a partial rotation is imparted to the crank-shaft 27 on the traverse block 21 near the reversal point. The elfect of such partial rotation of the crank-shaft 27 is to impose upon the normal movement of the traverse rod 17 received from the sliding movement of the traverse block 21 a brief secondary acceleration such that, where the invention is applied to a textile winding machine as hereinbefore described, the helix angle of the wound material is altered over a short length near the end of the package. When the cam-shaft 23 has rotated through and the auxiliary cam-follower 29 again operates the crank-shaft 27, the necessary acceleration is imposed again upon the normal'movement of the traverse-rod 17. t The axial length of thepackage over which the helix angle is altered may be varied to suit particular requirements. This may be achieved by the use ofa variablethrow crank on the traverse block 21, as shownin Figs. 5 and 6, where the crank-shaft 27 carries a member 261 carrying a lead-screw 262 on which is threaded a nut Said nut 263 is an integral part of a stud 264 which serves as a pivot for the connecting-rod 25. It will be seen that by rotating the screw 262, .the position ofthe nut 263, and therefore of the pivot-stud 264 from the rotary axis of the shaft 27 may be varied to adjust the stroke of the traverse-rod 17. Alternatively, means .may be provided for adjusting the angular distance by which the two cam- followers 20, 29 are separated in relation to the cam-shaft.

The mechanism provided by this invention may be used to off-set the disadvantageous effect upon the formation of-a wound package of yarn or thread which may arise from defects in the package-building mechanism. For example, a delay or dwell during the reversal of the traverse, which would otherwise produce an accumulation of the wound material near to the end of the package, may be countered by the means here provided for decreasing the quantity of material wound upon the end of the package by accelerating the traverse.

It will be understood that the foregoing references to the traversing motion of a guide are intended to include the relative movement of such a guide when the packagesuppor'ting spindle is subjected to an endwise traversing motion, or when such motion is shared by the guide and the spindle. 4 7

What "Iclaim as my invention and desire to secure by Letters Patent is;

l. A mechanism of the type referred to including a rotating cam, said cam-having a continuous cam groove, an output member, a first cam follower cooperating with said groove wherebyrsaid first cam follower receives a reciprocatory motion, said first cam follower being connected .tosaid output member and a second cam-followeras'sociated with said output member and disposed in such relation to the first cam-follower that immediately before or after reversal of-the output member due to the operation of the first cam-follower said output member receives a secondaryacceleration due to the operation of the second cam-follower.

2. The combination with a-rotating c-am, a cam-follower receiving reciprocatory' motion from its cooperation with assume said cam, and an output member partaking of said reciprocatory motion, of a second cam-follower mounted upon- "acrank-shaft rotatably supported by'a reciprocatory member associated with said first cam-follower, and arranged to cooperate with the cam before or after the first camfollower, whereby a part-rotary motion imparted .to said crank-shaft is effective to impose a temporary acceleration upon the output member.

3. A mechanism of the type referred to, including a link, a rotating cam, a first cam follower associated with said cam and connected to said link adapted to impart periodic motion to said link, and a second cam follower associated with said cam and connected to said link adapted to modify the motion induced in said link by said first cam follower, said first mentioned cam follower being mounted on a block which is slidable in the direction of the reciprocatory movement to be imparted to the traverse member, a shaft rotatable in said block, a crank on said shaft carrying the second mentioned cam follower, and a second crank on said shaft connected to said reciprocatory machine part.

4. A mechanism as claimed in claim 3, wherein the first-mentioned cam-follower is carried by an extension of the crankshaft.

5'. A mechanism 'as claimed in claim 3, wherein the two cam-followers are respectively mounted on the opposite limbs of a two-armed lever fixed to the crank-shaft.

6. A mechanism as claimed in claim 3, wherein the two cam-followers are respectively mounted on two opposite'ly disposed cranks fixed to the crank-shaft.

7. A mechanism as claimed in claim 3, comprising means for varying the amplitude of reciprocatory movement of the machine part.

8. A mechanism according to claim 3, comprising means for adjusting the throw of said second crank. f

9. A mechanism according to claim 8, wherein the secondcrank is provided with a crank-pin which is capable of adjustment longitudinally of the crank by a lead-screw rotatably mounted therein.

10. A mechanism according to claim 8, comprising means for adjusting the angular distance separating thetwo cam-followers in relation to the cam-shaft.

11. A mechanism as claimed in claim 3, wherein the cam-followers are rotary 'bowls respectively mounted for rotation about axes which intersect in the rotary axis of the cam.

'References Cited in the file of this patent UNITED STATES PATENTS 651,828 Copland June 19, 1900 764,470 Jones July 6, 1904 1,384,344 Powell July 12, 1921

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