US2467952A - Antonevich - Google Patents

Description

M. ANTONEVICH STOP MOTION MECHANISM April 19, 1949.

2 Sheets-Sheet 1 Filed April 8, 1948 36 MG. ii.

FIG. 2

by his Hfiornegs Filed April 8, 1948 2 Shets-Sheet 2 225/7715 Hiforneys k WW Rue/770k Mchagl Hnfonew'ch l l J Patented Apr. 19,1949

STOP MOTION MECHANISM Michael Antonevich, New Brunswick, N. J., as-

signor to Crawford Manufacturing Company, Inc., New Brunswick, N. J., a corporation of New Jersey Application April 8, 1948, Serial No. 19,841

18 Claims. (Cl. 66-163) This invention relates to textile machinery and. more particularly a device used on a knitting machine which tensions the yarn and at the same time automatically stops the knitting machine in the event that the desired tension in the yarn becomes too great or too small.

A standard stop motion or stop mechanism customarily employs a pivotally mounted finger over which the yarn passes as it is fed from the spools or bobbins to the needles. If for any reason the yarn becames too taut, for example when a knot in the yarn is caught by the strainer, the tautness of the yarn depresses the stop motion finger, thereby closing an electrical circuit to a relay which in turn stops the main knitting machine motor. Furthermore, in the conventional stop motion device should the yarn break or become slack for some reason, the spring-loaded finger pivots upwardly to actuate the relay, likewise shutting down the knitting machine so that suitable adjustment can be made.

Patents disclosing devices of this general nature are: No. 1,816,765, A. Crawford; No. 2,178,982, M. Wachsman; No. 2,248,315, M. Wachsman; and No. 2,290,303, E. Vossen.

Two serious disadvantages have been found however, with stop motion mechanisms of the prior art. The first is due to the fact that these devices do not provide for supplementary tensioning for the finger under slightly increased conditions of yarn tautness. The second and more important disadvantage resides in the fact that the knitting of certain articles, such as stockings, requires some needles of the knitting machine to remain idle when the diameter of the stocking is decreased. Continued operation of the knitting machine then causes the idle spools or bobbins to rotate on their spindles and this in turn produces considerable slack in the idle yarn between the spools and the stop motion device. The stop mechanism over which the unused threads or yarn are run, thereupon shuts down the entire knitting machine even though a relatively slight amount of slack occurs for the above reason. This constant shutting down of the machine has been the cause of much lost time and is highly undesirable.

A primary object of the invention therefore, is to provide an improved stop motion mechanism for knitting machines which will not shut down the machine when slack occurs between the stop motion and the spool.

A further object of the invention is to provide in a stop motion device an adjustable tensioning finger which is spring-loaded over a portion of finger travel and which is counterbalanced to provide a non-adjustable tension on the yarn throughout a further portion of finger travel.

A further object of the invention is to provide a supplementary tensioning finger or spring which resists excessive finger depression due to increased tautness in the yarn.

A still further object is to provide in a stop motion mechanism a single spring-loaded adjustable contact mechanism which closes an electrical circuit both when the control finger is depressed beyond a predetermined point, and when it is raised beyond a predetermined point.

Further objects will be apparent from the specification and drawings in which:

Fig. 1 is a perspective of a preferred form of stop motion mechanism constructed in accordance with the invention;

Fig. 2 is an end elevation of the structure of Fig. 1 partly broken away;

Fig. 3 is an elevation partly broken away of the opposite end of the structure of Fig. 1, with the end plate removed;

Fig. 4 is a detail of the electrical contact shown in Fig. 3 in closed position;

F Fig. 5 is a rear elevation of the structure of Fig. 6 is an end elevation of the structure of Fig. 1 showing the position of the fingers when slack occurs between the stop motion and the spool;

Fig. 7 is a sectional detail as seen at 'l'! of Fig. 5 showing the fingers in the position of Fig. 6;

Fig. 8 is a fragmentary detail of the finger positioning and interlocking structure as seen at 8-8 of Fig. 2;

Fig. 9 is an enlarged fragmentary detail of the position of the fingers when excessive tautness occurs in the yarn, and showing the yarn about to slip from the fingers;

Fig. 10 is an enlarged fragmentary detail of the fingers in normal operating position, as shown in Fig. 1;

Fig. 11 is an enlarged fragmentary detail of the fingers in the position when there is excessive slack or the yarn breaks between the stop motion and the needle;

Fig. 12 is a perspective of a modified form of stop motion having two fingers instead of three;

Fig. 13-is a fragmentary sectional detail as seen at l3 l3 of Fig. 12;

Fig. 14 is a fragmentary sectional detail as seen at l4l4 of Fig. 12;

Fig. 15 is an end elevation of the structure of Fig. 12 with the cover removed;

Fig. 16 is an elevation of the opposite end of the structure of Fig. 12 with the cover removed;

Fig. 17 is a detail of the spring-loaded electrical contact plate in the position of Fig.

Fig. 13 is a fragmentary detail on a reduced scale showing the position of the fingers in the position when there is excessive slack or the yarn breaks between the stop motion and the needle;

Fig. 19 is a fragmentary detail on a reduced scale showing the fingers when excessive tautness occurs in the yarn, and showing the yarn about to slip from the fingers;

Fig. 20 is a fragmentary detail on a reduced scale showing the fingers in the position when slack occurs between the stopzm'otion and the spool and corresponds to the position of the fingers in Figs. 6 and '7;

Fig. 21 is a perspective showing the detailed construction of the fingers, counterweight's, andactuating pivots; and

-Fig. 22 is a fragmenentary detail as seen along 2'2--22 of Fig. 12 showing the top view of the finger pivoting structure.

The invention: comprises essentially the provision in a stop motion device of a clamping finger operatively associated with a rigid arm in such away that normal operating tension on the yarn or threadsas it passes over the fingers of the stop motion pivots the clamping finger away from the rigid arm, but when tension is decreased to a predetermined value, the finger presses the yarn against the arm to prevent actuation of the stop motion mechanism. The clamping finger as well as the stop motion and/or tension fingers are pivotally interlocked so that when the stop motion finger is depressed, the other finger or fingers are automatically depressed. The preferred form of the invention has separate clamping and supplementary tensioning fingers which are so constructed that when the clamping finger is depressed, only the supplementary tensioning finger is depressed automatically and when the main tensioning finger is depressed, both the clamping and supplementary tensioning fingers are automatically depressed.

The invention includes a' modified form in which the supplementary tensioning spring acts directly on the clamping finger.

Referring now more particularly to Fig. l of the drawings, the preferred form of the invention comprises a vertically positioned housing 25 having a removable cover 26 to which is attached a: bracket 21 for supporting the entire stop motion device on a knitting machine. The inner wall 28 of'housing 25 (Fig. 5) is elongated and bent at right angles to form a bracket 29 to which is bolted or otherwise attached a horizontal frame member 36'. A pin or shaft 3| is rigidly supported in rear wall 26 of housing 25 so that the yarn contacting fingers 32, 33 and 34 are supported by, and journaled on, shaft 3|. Both fingers '32 and 34 are provided with conventional ceramic caps 35 on which the thread or yarn 36 runs, and in addition, have integral counterbalances 31 and 38 and areaxially spaced and journaled on shaft 3| by means of bushings 33 and 40. Likewise, clamping finger 33 with integral counterblance 4| is mounted on shaft 3| through bushing 42. Finger 33 may be formed from a double loop of wire having'straight sides extending at right angles to shaft 3|. In the preferredembodiment, finger 33 is positioned between fingers 32 and 34 so that it is unnecessary to provide a ceramic cap for finger 33 because the caps 35 on fingers 32 and 34 serve to guide and 4 contact the yarn under normal operating conditions.

Referring now to Fig. 2, it will be seen that shaft 3| extends into housing 25 and journals a pivoting contact plate or member 43. Plate 43 is connected to, and at all times turns with, finger 32 by means of a connecting pin 44 extending through an arcuate slot 45 in rear wall 28. The hub 32a of finger 32 also carries an actuating pin 46 which extends parallel to shaft 3| and over the shank of finger 33 so that as finger 32 is depressed, finger 33 is likewise depressed when pin 46 contacts the shank of finger 33. A similar action between fingers 33 and 34 is achieved by means of pin positioned in the hub 34a of finger 34 and extending at right angles to the fingers but underneath the shank of finger 33 so that as finger 33 is depressed, finger 34 is automatically depressed when the shank of finger 33 strikes pin 41. In this way it will be seen that finger 34' may be moved independently of the other two fingers, whereas when finger 33' is depressed, it carries with. it only finger 34, but when finger 32 is depressed,'both fingers 33 and 34 are likewise depressed.

Referring more particularly to the action and cooperation between fingers 33 and 34, it will be noted in Fig. 2 that the upward pivoting movement of finger 34 is controlled by means" of an adjustable limit stop 53 secured to the horizontal member 36 by means of screw 5|. Downward pivoting of finger 34 is' controlled by means of a helical torque spring 52 (Fig. 5), one end of which is secured in a serrated thumb nut 53 rotatably mounted onshaft 54 which is in turn supported in a downwardly depending flange 55 on member 33. A friction latch comprising a leaf spring 5'6 retains any desired adjustment of nut 53- and is secured to member 30 by means of screws 51, 51.- The other end of spring 52 is mounted in link 58 pivoted on shaft 54 at one end, and to cross-link 59 at the other. Link 59 is likewise pivoted to counterbalance 38 by means of pin 60 (Figs. 2 and 8') sothat torque of spring 52 is transmitted to finger 34 through both links.

When finger 34 is in the'raised position of Fig. 2 so that itabuts limit stop 50, and when clamp-- i-ng finger 33" is likewise in the fully raised posi tionas shown in Figs. 6 and 7' so that it abuts the undersurface of backing member 6|, a slight clearance is provided between actuating pin 41 in counterbalance 38 and the underside of the shank of finger 33 as shown in Fig. 7. This clearance permits limited pivoting of finger 33 controlled only by counterbalance 4|. Furthermore, the weight of counterbalance 4| is just enough to clamp thread 36 between finger 33- and backing member 6| in the event that slack occurs between the spool and the stop motion device. In this condition, no tension is imparted to the thread by means of finger 34 since the stop 56 prevents further upward movement of finger 34.

The cooperation and action of stop motion finger 32 is such that when a knot or other obstruction occurs in thread 36, the increased tension in the thread depresses finger 32, and automatically fingers 33 and 34, until plate 43 pivots on pin 3| to the extent that corner 62 of plate 43- touches insulated'electrical contact 63 as shown in Fig. 4'. Contact 63 is supported from member 30 by means of binding post'64, nut 65 and insulating bushings and washers 66, 51 and 68. Binding post 64 is connected to a relay which controls the main knitting machine'm'otor so that if finger 32 is' sufficiently depressed, the machine will be -stopped until the necessary repairs or adjust.-

ments can be made. The additional electrical elements and their operation are well known in the knitting machine art, and it is therefore believed unnecessary to describe them in greater detail.

Tension spring I (Figs. 3 and 6) is mounted on pin 1| on plate 43 at one end, and to a sleeve or plate 12 at the other end. Tension in spring 10 may be varied by means of serrated knob I3 which is integral with screw-I4 engaging internal threads in plate 12. Knob I3 is retained in any desired position by means of friction finger I5 secured to housing 25 by means of screws I6, I6. It will thus be apparent that main tension spring I0 controls the pivoting movement of finger 32 at all times and in all positions so that the adjustment of this spring supplies the proper tension to the yarn for normal running. 1 However, if less than normal running tension occurs in the yarn, the finger will pivot upwardly due to the force of spring I0.

In the event that the spool, from which thread 36 is fed, be disconnected from the knitting machine as is often the case or should there be a slight slack in the threads between the spool and the stop motion, finger 32 will pivot upwardly on shaft 3| to approximately the position shown in Figs. 6 and '7. The decreased or limited slack condition in the yarn between the stop motion and the needle prevents further upward pivoting of finger 32 in accordance with the adjustment of spring 10. This controlled or limited upward pivoting of finger 32 permits the knitting machine to continue in operation without actuating the stop relay since plate 43 is so constructed that the opposite corner 'I'I does not strike contact 63 until additional upward pivoting has occurred.

This is an important feature of the invention because in stop motion devices heretofore used, if slack occurred anywhere in the yarn between the spool and the needle, the stop relay was actuated thereby preventing operation even though continued operation with only a limited number of spools was required. Since the thread 36 is still engaged in the inoperative needle and since the thread is also'clamped between finger 33 and backing member 6| in accordance with the weight of counterbalance M, the upward movement of stop finger 33 is thus controlled and retained within the are bounded by respective con-- tact positions of corners 62 and T1 of plate 43 with contact 63. However, should excessive slack occur between the stop motion and the needle, as would be the case if the thread breaks, there is no restraint for upward pivoting of finger 32 and the stop relay is actuated when corner I! touches contact 63. The position of finger 32 under these conditions is shown in Fig. 11.

It wil1 be apparent that the stop mechanism is operative to shut down the knitting machine in the event of a broken thread regardless of whether the break occurs between the stop motion and the needle as described abOVe, or between the stop motion and the spool. In the event that the break occurs between the stop motion and the spool, the slack thus caused in the thread will immediately permit finger 34 to pivot upwardly until it abuts stop 50. Likewise, finger 33 will pivot upwardly due to counterbalance 4| and lightly clamp the thread against member 6|. However, this clamping pressure is sufficient to permit only limited upwardpivoting of finger 32 as shown in Fig. 6 and the thread continues to run through the stop mechanism untilthe'break passes finger 33. .At this point there isn'o longer any restraint on finger 32 due to yarn tension'so that the finger immediately springs to the position of Fig. 11, thus stopping the machine in order that necessary repairs can be made. It will be noted that in the position of Fig. 6, corner 11 does not close the electrical circuit to the relay so that the machine continues to operate.

In normal operation, finger 32 supplies the entire thread tension by means of spring Ill due to the fact that finger 34 is automatically restrained by stop 50. The slight friction of finger 33 on the thread may be disregarded for purposes of thread tension due to the fact that counterbalance 4| barely overcomes the weight of finger 33. However, if the thread becomes tighter than would be the case under normal operating conditions, all fingers are depressed which brings into play the opposing tension of spring 52. If the taut condition is cured, the fingers return to their normal operating position without shutting down the machine. However, if the tension in the thread is not relieved, the fingers will be depressed to approximately the position of Fig. 9 whereupon the thread either slips off of finger 32 or the knitting machine is stopped due to closing of the circuit by engagement of corner 02 of member 43 with contact 63 as shown in Fig. 4. Of course, if the thread does slip completely ofi of finger 32 before this engagement is made, spring 10 instantly pivots finger 32 upwardly to the position of Fig. 11 so that the machine is stopped in either case.

Referring now to Figs. 12-22, I have provided a modified form of stop motion structure which enables the same results to be achieved as was done with the structure of Figs. 1-11, but instead of three fingers there are only two in this form. The stop motion housing comprises a horizontal plate member I00, the edge of which is bent downwardly at right angles to form sides IOI and I32 to which are attached vertical housings I03 and I04. The entire assembly has a generally inverted U shape. Covers I05 and I06 are secured to the housings I03 and I04 respectively by means of suitable screws I01. The fingers I08 and I09 pivot on shaft H0 which is rigidly mounted in the rear walls III and H2 of housings I03 and I04 respectively (Fig. 22). Axial positioning of the fingers is achieved by means of a long bushing II3 between the finger hubs I 08a and I090: and short bushings H4, H4 between the hubs and walls III and H2. Fingers I08 and )9 are provided with counterbalances I I 5 and I I3 which serve to balance the weight of the fingers. The tops of the fingers curve downwardly in a longitudinal direction as shown in Figs. 15 and 16 and also are upwardly convex to present a smooth running surface for thread I I1.

Finger I08 is provided with a prong H3 to prevent thread I I! from running up on the finger, and the shank [08a of finger I08 has a laterally extending abutment II9 positioned to overlap a similar abutment I20 on the shank I 09a of finger I09 (Fig. 22). The positioning of abutmentsv H9 and I20 is such that finger I09 may be fully depressed without afiecting finger I00, whereas depression of finger I08 automatically depresses finger I09. The fingers of Figs. 12 to 22 are formed of thin sheet metal which may be stampedto provide the desired shape. An abutment or rigid arm I 2| having a lower arcuate edge of the same shape as finger I09 is secured to side IN by means of screw I22so that when finger amp-ca I09is raised to its maximumposition, thread. I111 is lightly clamped between the finger and arm I2I as shown in Figs. 18 and 20.

The portion of shaft IIO which extends: into housing I03 is provided with a. spacing bushing or collar I23 and journals a contact plate or member, I24 similar to plate 43 of Figs. 3 and. 6. Member I24 is spring-loaded by means of helical tension spring I25 connected thereto by pin- 126. The other. end of spring" I25 is attachedto an internally threaded nut I21 which may beraised and; lowered in the bottom portion of housing I03 by means of serrated knob I28 and threaded screw I29 engaging nut. I21 (Fig. 16).. Actuation of. plate. I24 by means of finger I08 is provided through pin I30 rigidly connecting thecounterbalance N of finger I08 and the plate through an arcuateslot..I:.3I in wall II I. Itwilll'therefcre, be apparent that "the tension applied to finger I108 depends,uponJthe-adjustment of knob I28 in substantially the same manner as. the structure of Fig. 6.

Referring now to the opposite housing I04 (Fig. 15) into which pin II'0 likewise extends. a link I32. is journaled on pin III) and spaced from wall II2 by means of bushing I33, Fig. 22. Link I32 is spring-loaded in the same manner as contact I24 by means of helical tension spring 134 supported on the link by pin I35 and connected to threaded nut I36 which is movable in housing I04 by means of thumb nut I31 and :screw I38. Plate I32 is provided with a pin I39 extending through arcuate slot I40 in wall I I2 of housing I04 in such a way that pin I39 is parallelto pin H0 and extends over the counterweight M0 on finger I09. The location and adjustment of'pin I39 with respect to counterweight I and slot I 40 is important and provides-the proper tensioning of finger I09 under various operating conditions.

Referring now to Fig. 15, it will be seen that pin I39 abuts the left hand. extremity I40a-of slot I 40. This removes all pressure ofspring I34 from finger I00 and the location or the slot terminus I401: with respect to the bottom edge of arm I2I as well as the location of the point of contact between pin I39 and counterbalance IIS is such that slight free pivoting movement of the finger is provided before finger I09 contacts arm I2I'.

This will be apparent by referring to Fig. in

which thefinger I09 is shown in the position of maximum. depression without extending spring I34. Any additional downward pivoting of finger I09 will be controlled by spring I34 through the pin I39 (Fig. 13), but upward pivoting from the positioncf Fig. 15 is controlled only by the counterbalance IIB, the weight of which is sufiiciently greater than the weight of finger I09 to providethe desired clamping pressure 'on the yarn.

In this way,.when slack occurs in thread -I I1 between the stop motion and the spool, the thread is securely but lightly clamped between finger I09 and arm I'2I by means of counterbalance I I6 only.

Increased tension in the thread 'II'I depresses the fingers so that when the tension is suflicient to depress either finger below the position shown in Figs. 15 and 16, spring I34 automatically comes into play to resist further depression, thereby tending to return the fingersto normal operating position. However, :it willbe seen that the tension insprin-g I25 is transmitted. tothe threadv III; at all timeswhen the thread is on finger I08 and: thiscis suflicient to provide the may be. one of two conditions.

normal operating tension. The additional tension orsprin-g I34 comes into play only whenmore than normal tautness in thread III occurs, and such additional tension is provided. regardless of which finger may be depressed the most since fuither downward pivoting of finger I08 automatically pivots finger I09 by means of abutments M9 and I20.

The. electrical stop motion construction of the modified form of Figs- 12 tov 22 operates in a manner generally similar to that. of Figs. 1-11 so that. limited pivoting of finger I08 without closing; the. circuit is provided. In the event that slack occurs between the stop motion and thespool, thread III will be lightly clamped between finger I09 and arm 'I.2I.. Since the thread remains. in the needle of the knitting machine, finger: I08 will pivot upwardly untilv the slack be.- tween the stop ,motion and the needle is taken up. In this position finger I08 will be slightly raised as shown in Fig. 20. The pivotal position of contact member I24 correspondingto the positionoi' finger I08 in Fig. is shown in Fig. 17, and in thisposition the circuit isstill open. Further upward pivoting of finger I08 immediately causes the corner I4I of contact I24 to touch the insulated spring clip I42 thereby stopping the knitting machine. Clip I42 is secured to the top of housing I03 by means of plate I43, insulating washer I44, insulating bushing I40 and screw I48. A suitable binding post I41 is retained by screw I46 and is electrically connected to the main relay in the conventional manner.

In the event that thread II'I becomes exce sively taut, fingers I08 and I09 pivot downwardly until. they reach the position shown in Fig. 19. At this point contact member I24 is turning counterclockwise in Fig. 16 and corner I48 of member I24 will engage clip I42 to actuate the stcprelay. Whether thread. I I1 slips completely off of finger I00 before corner I48 completes the circuit is relatively immaterial because if the thread does slip off finger I08, the finger immediately pivots upwardly to the position shown in Fig. 18, likewise actuating the stop relay by means of corner I4I on contact I24. These alternate circuit closing positions of plate I24 are shown by the fragmentary dotted lines in Fig. 16.

It will. thus be apparent that I'have provided an improved stop motion device which is capable of handling any possible thread condition occurring in the knitting machine.

, When there is excessive tautness, increased tension in the fingers is automatically provided by means of a. reserve or supplementary spring. In the event that the tension of the reserve spring is still insufficient, the fingers are further depressed in which case the stop relay is energized; by means of the completed relay circult actuated by the finger, or the thread slips ofi? ofthe fingers which also insures actuation of the stop relay.

When slack occurs in the thread, the cause First, the slackness may be due to a broken thread. Should the break occur between the stop motion and the needle, all resistance to the springs I0 or I is removed, thus permitting the stop finger to fly upwards and actuate the stop relay. In the event that the thread breaks between the. stop motion and the spool, the relay will not be actuated until the break passes under the clamping finger and backing member, but as soon as this occurs, the stop finger immediately flies upward since all resistance to the stop finger spring is thus removed. The second and most important feature of my construction resides in the fact that when only limited slack occurs in the thread, which slack may be caused by vibration in the knitting machine or the fact that certain spools are not used in performing part of the knitting operation, the stop finger is prevented from shutting off the machinedue to the controlled clamping action of a second finger against a backing member in conjunction with limited pivoting of the stop finger without closing the circuit to the stop relay.

I claim:

1. A stop motion assembly for knitting machines comprising a'housing, a plurality of fingers pivoted in said housing, and a rigid arm attached to the housing in registry with one of said fingers whereby a thread is pressed between said arm and one of said fingers when the finger pivots toward the arm..

2. A stop motion assembly in accordance with claim 1, in which one of said fingers actuates an electrical contact to close a relay circuit when the finger is in maximum raised and depressed positions and in which the relay circuit remains open when the finger is intermediate said maximum raised and depressed positions.

3. A stop motion assembly in. accordance with claim 1, in whichone of the fingers is spring-' loaded throughout the entire pivoting movement of the finger. and means for adjusting the tension of said spring.

4. A stop motion assembly in accordance with claim 1, in wh ch one of the fingers is springloaded duringthe lower'portion of finger travel only, and an abutment for said finger to limit further upward pivoting.

5. A stop motion assembly in accordance with claim 1, in which one of the fingers serves as a main yarn tensioning finger and is provided with an adjustable tensioning spring for substantially the entire pivoting arc of the said finger, another of said fingers serves as a supplementary tensioning finger and is provided with a spring operable on said supplementary finger over the range of finger movement from normal operating position to a position of maximum finger depression, means for removing the spring action from said supplementary finger at a point below the position of normal operation, and a counterbalance for the finger for controlling further pivotal movement of the finger.

6. A stop motion assembly for knitting machines and the like, comprising an L-shaped housing having a horizontal portion and a vertical portion, a horizontal shaft rigidly attached to the vertical portion, a main tensioning finger pivotally mounted on said shaft, a counterbalance for said main tensioning finger, a clamping finger pivotally mounted on said shaft, a counterbalance for said clamping finger, a supplementary tensioning finger pivotally mounted on said shaft, a counterbalance for said supplementary tensioning finger, means for axially spacing the hubs of said fingers on the shaft, a stationary arm attached to the horizontal portion of the housing, a face on said arm adapted to register with the upper surface of the clamping finger, a contact plate pivotally mounted on the shaft in the vertical housing portion, a spring attached to said contact plate, means for adjusting said spring, a rigid connection between the contact plate and the main tensioning finger, a supplementary spring mounted in the horizontal housing por- '10 tion, means for transmitting torque from said supplementary springto the supplementary tensioning finger, means-for adjusting said supplementary spring and a stop for limiting upward pivotal movement of said supplementary pivoting spring.

7. A stop motion assembly in accordance with claim 6 having an axial pin extending from the hub of the main tensioning finger over the shank of the clamping finger, an axially extending pin in the hub of the supplementary tensioning finger extending axially under the shank of the clamping finger, so constructed and arranged that when the main tensioning finger is depressed, both the clamping and supplementary tensioning fingers are automatically depressed and when the clamping finger is depressed only the supplementary tensioning finger is depressed and the clearance between the shank of the clamping finger and the axially extending member in the hub of the supplementary tensioning finger so that limited free pivoting between the arm and the clamping finger is controlled only by the clamping finger counterbalance is provided.

8. A stop motion assembly in accordance with claim 6 in which the contact plate in the vertical housing is flattened to provide limited pivoting of the main tensioning finger without closing the circuit to the relay.

9. A stop motion assembly for knitting machines and the like, comprising an L-shaped housing having a horizontal portion and a vertical portion, a horizontal shaft rigidly attached to the vertical portion, a main tensioning finger pivotally mounted on said shaft, a clamping finger pivotally mounted on said shaft, a counterbalance for said clamping finger, a supplementary tensioning finger pivotally mounted on said shaft, means for axially spacing the hubs of said fingers on the shaft, a stationary arm attached to the horizontal portion of the housing, a face on said arm adapted to register with the-upper surface of the clamping finger, a contact plate pivotally mounted on the shaft in the vertical housing portion, a spring attached to said contact plate, means for adjusting said spring, a rigid connection between the contact plate and the main tensioning finger, a supplementary spring mounted in the horizontal housing portion, means for transmitting torque from said supplementary spring to the supplementary tensioning finger, means for adjusting said supplementary spring, and means for pivotally interlocking said fingers.

10. A stop motion assembly in accordance with claim 9 having a counterbalance for the main tensioning finger and a counterbalance for the supplementary tensioning finger.

11. A stop motion assembly in accordance with claim 9 in which the pivotally interlocking means comprise an abutment extending axially from the shank of one finger to overlap the shank of an adjacent finger whereby pivoting of the first finger is transmitted automatically to the second finger, and pivoting of the second finger occurs without affecting the first finger.

12. A stop mo ion assembly for knitting machines and the like comprising a U-shaped housing having a horizontal portion and a pair of vertical portions, a horizontal shaft rigidly sup ported between the vertical portions, a main tensioning finger pivotally mounted on said shaft, a supplementary tensioning finger pivotally mounted on said shaft, a stationary arm mounted housings adapted to resist downward pivoting of 5 said supplementary finger, means foroonnecting said spring to the shank of said supplementary finger, an abutment for said connecting means, said abutment being positioned to provide limited finger pivoting with said spring inoperative on 10 the supplementary finger, a second spring adjustahly vmountedin the other vertical housing, and means for connectingv said second spring to the shank of the first tensionint finger.

13. A stop motion assembly for knitting me.-

chines and the like comprising a 'U -shaped housing having .a horizontal portion and a pair of vertical portions, a horizontal shaft rigidly supported between the vertical portions, a main tensioning finger-pivotally mounted on said shaft, a go supplementary tensioning finger pivotal1y mounted on :said shaft, a stationary arm mounted on the horizontal portion and in registry with the supplementary tensioning finger, a counterbalance for the supplementary tensioning finger, a supplementary spring in one of said vertical housings adapted to resist downward pivoting of said supplementary finger, means for connecting said spring to the shank of said supplem'entary finger, an abutment for said connecting means, said abutment being positioned to provide llmitedtlnger pivoting with said spring inoperative on the supplementary finger, a second spring adjustably mounted in the other vertical housing, means for connecting said second spring to the shank of the first tensioning finger, and an electrical contact in said second vertical housing operable to close an electrical circuit 'upon maximum pivoting of the main tension'ing finger.

14. A stop motion assembly in accordance with claim 13 in which the main tensionlng finger is provided with a prong to limit longitudinal yarn movement thereover.

15. A stop motion assembly in accordance with claim 13 in which the main tensioning finger is provided with an axial extension adapted to overla the shank of the supplementary finger so that depression of the main finger automatically depresses the supplementary n 16. .A stop motion assemblyaccordanoe with claim 13 in which the'abutment -.compr.ises an arcuate slot in the rear wall of the first vertical housing, a pin adapted to extend through said slot and overlap theshank of the supplementary finger, and aiconnectingplatc nivo'tally mounted on said shaft, said connecting plate supporting the pple entary tension spring and the pin.

17. A stop motion assembly in accordance with claim 13 in which the fingers are formed of longitudinally concave and transversely con-vex metallic stamplngs.

18. A stop motion assembly in accordance with claim '13 having an electrical contact pivotally mounted in the second vertical portion, a connecting oar between said contact and the main tensioning finger whereby the contact and the main tensloning'finger move as a unit, a stationary electrical contact mounted in said vertical portion, and a flat on the pivoting'contact whereby an electrical circuit is closed when the finger is pivoted to maximum downward position and when the finger is pivoted to a maximum upward position but in which "thec'ircuit remains open during intermediate pivoting of the "finger.

' T ONEVICH.

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

STATES 'PATENTS Number Name Date 13 1 Crawford ""99-" July 8, 193 2,17 ,982 'Wachsman Nov. .7, 1 .39 2,248,315 'Wac'hsman July 8, 1941 2,251,030 Antonevich "u.--" Sept. 23, 1941 2,290,303 Vossen ,July ,21, 1942 2,420,513 Arrowooric...v May 113, 1947

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