US2257037A - Stop motion device for knitting machines - Google Patents

Description

p 1941. A. CRAWFORD 2,257,037

STOP MOTION DEVICE FOR KNITTING MACHINES Filed April 5, 1939 Patented Sept. 23, 1941 STOP MOTION DEVICE FOR KNITTING MACHINES Alfred Crawford, New Brunswick, N. J., assignor to Crawford Manufacturing Company, New Brunswick, N. J a corporation of New Jersey Application April 3, 1939, Serial No. 265,822

12 Claims.

This invention relates to faulty-needle and snarled-thread detectors, for use with electrically-operated stop motions of knitting machines, such, for example, as the stop motions disclosed in my prior U. S. Patents No. 1,992,860, dated February 26, 1935 and No. 2,145,754 dated January 31, 1939, which latter constitutes an improvement over the structure disclosed in the earlier patent,

In each of the above noted cases, broken or bent needles or latches, or thread snarled or bunched on a needle as a result of the improper operation of the needle or its latch, or which results from a knot or other irregularity in the knitting thread or in the knitting operation, are detected by purely mechanical means. The mechanical devices include a detector finger which is arranged to engage or to be engaged by a faulty needle or a snarled bunch of thread. The finger, in turn, controls a spring-loaded plunger arranged, when released, to drop behind one of a series of abutments formed on a floating ring which is loosely mounted for rotation in a circular groove formed in the frame of the knitting machine, concentric to the axis of the needle cylinder. levers and links designed to interrupt the application of power to the machine and to apply a brake for overcoming the momentum of the machine, as a result of operation ofthe primary detecting finger.

When using constructions such as noted above, there is a certain amount of delay in the stopping of the machine after the detecting finger has been initially actuated, due to there being a certain amount of rotation of the machine parts required to release the plunger, for the plunger to engage an abutment on the ring, and for the ring to trip the power interrupting and brakeapplying mechanism.

The primary object of the present invention is to provide an electrical detector which may be connected in the same electrical circuit as the detectors disclosed in said patents for slack, taut or broken threads, whereby actuation of the needle or snarled-thread detcetor will immediately actuate the trip motor of the stop motion, in the same manner as the other thread detectors of the stop motion, whereby interruption of the power to the machine and the application of the brake Will be effected immediately upon operation of the needle and snarled-thread detector.

The mechanical detector above noted also requires that an annular space be reserved com- The ring, in turn, operates a train of pletely around the needle cylinder andits cam ring, outside the latter, for the plunger mechanism and the ring to operate in. The necessity for providing such space has prevented the placing of attachments on the frame of the machine in close proximity to the needle cylinder or its cam ring.

Another object of the invention, therefore, is to construct a needle and snarled-thread detector in a manner making it possible to eliminate the plunger, ring, and other mechanical connections formerly required to stop the machine by operation of the needle and snarled-thread detector and which necessitated the reservation of lost space, outside the cylinder and cam ring.

Another object is to .construct'the device in such a manner that it may be mounted above the upper end of the needle cylinder, to'operate within a circle of a diameter substantially no greater than the outside diameter of the needle cylinder and less than that of the cylinder cam ring, whereby the space normally required for operation of the mechanical detector and the ring forming part thereof may be utilized for the placing of other attachments close to the cylinder and cam ring.

Another object of the invention is to construct the device in such a manner that upon operation of the sensitive element by engagement thereof with a knot, etc., said element will be automatically moved out of engagement with the obstruction upon effecting operation of the stop motion.

The construction and operation of detector devices made and mounted on knitting machines in accordance with the principles of the present invention will be fully disclosed hereinafter, reference being had to the accompanying drawing of which Fig. 1 is a perspective view of thepreferred form of a detector device constructed and adapted to operate in accordance with the present invention;

Figs. 2 and 3 are side elevations of the detector device mounted on the dial cam plate of a rib knitting machine, or ona corresponding cap plate frequently arranged atthe otherwise open end of the needle cylinder of a plain non-rib knitting machine with the device in its normally set condition in Fig. 2 and tripped in Fig. 3;

Fig. 4 is a rear elevation of the device;

Fig. 5 is a sectional elevation taken on the line 5-5, Fig. 4, showing the detector in a set position, as in Fig. 2;'

rotatably mounted a detector shaft 20.

I is provided with the usual vertical grooves 2 in which the cylinder needles 3 are vertically re-' ciprocated, in the usual manner.

In some instances plain knitting machines are provided with a horizontal plate It]; axially aligned with the needle cylinder l and positioned adjacent the normally open'upper end of the needle cylinder, such plate being supported in" the manner disclosed in the above mentioned patents. The plate I normally supports the thread feeding mechanism and other components orthe machine.

in the present instance the plate in repre-.

sents the dial cam plate ofa rib knitting machine and is disposed in superposed relation to the needle dial 'plate 9 which is provided with the usual radial grooves 8 in which the dial needles 1 are "slidably mounted for radial reciprocation by earns carriedbythe camplate H). V

The detector device of the present invention comprises a substantially rectangular bod-y eleinent H which may take the form of a solid casting' or a suitable hollow casing which in either case includes a 'backwall 12, side walls l3 and M re pectively, top and bottom walls l5 and I5 respectively, and a front wall 11.

Pi'vot'ed to the body eleinentll adjacent each of the side walls l3 and I4 is a lever I8 which is provided with an integrally formed outwardly projecting boss 19. 'In the boss or bearing I9 is Near the outer end of the detector shaft 20, said, shaft is drilled transversely for reception of the upper end of an adjustably mounted detecting finger 2!. The finger ;2l,;as shown-in Figs. 1 and 2 is provided with a pointed lower end 22. The pointed 7 end 22 of the'detector finger 2! normally lies immediately adjacent and substantially parallel -to the outer faces of the cylinder needles 3, and terminates at a point immediately adjacent and above the upper faces of the dial needles I, to be engaged by either the cylinder or dialneedles if bent from their normal positions or by the latches 5 and 6-of the cylinder needles 3 anddial needles 1 -.respectively, under irregular conditions, or. by the knitting thread a: should such thread bunch up on one or the other of the needles and project into the angle formed between the outer andupper surfaces o'fthe cylinder and, dial needles respectively.

T e needle detector 2| is offset longitudinally below the shaft 20, as indicated at 23, whereby,

upon loosening the set screw 24 which is mounted in the outer end of the shaft 2;), the pointed end 22 0f the detector finger 2 I may be swung about r the axis o'f-the' upper main portion of the finger 2i and thereby moved toward or away from the 1 cylindern'eedles 3, by rotation ofthe finger 2i i lntheshaftQQ; and moved toward or away from the dial needles 1 by axially sliding the finger 2| in its transversely extending bearing in the shaft 23, i. eat right angles to the axisof the shaft. after whichtightening of the set screw 24 will retain the linger in its desired position.

The body element l l is provided with a foot or bracket which may be formed as a part of the casing or separately therefrom and secured thereto by any suitable means, such, for example, as by screws 26. The foot 25 has a slot 21 for passage of screws 28 by which the device is secured to the plate l0.

Axial movement of the shaft 23 relative to the boss I9 is prevented, in one direction, by a collar 29 secured to the shaft and bearing against the outer end of the boss 19 and. in the opposite direction, by a lever 30 which is secured to the inner end of the shaft 20, between the inner end of the boss lil and the frontface ll of the body element H, as by a dowel, set screw or riveting, by which it is retained against relative rotation and axial .movementwith respect to the shaft 2i].

The upper end of the lever 38, when the detector finger 2 1 is set, is adapted to rest in a recess 32' which is formed in a cam or guide plate 33. The guide plate 33 is secured to the top surface !5 of the body element II by screws 34, 34 as shown in- Fig. '7. The recess 32 is formed by the intersection of two right angle shoulders 35 and 36. The'cam or guide plate 33 also includes a cam or guide surface 31 which extends at an angle to the surface of the shoulder 36 and inter-' sects said surface in spaced relation to the intersection of the surface of the shoulder 33 with the surface of the shoulder 35. v

The lever I3 is of forked construction having arms 38 and 39 disposed at opposite sides of the body element H adjacent the opposite side walls or faces 13 and I4 respectively. A pivot shaft 40 extends through the arms'38 and 39 and the body element ll therebetween and provides a pivotal connection between the lever l8 and the body element H.

The pivot shaft 40 is diametrically reduced a that end which fits into the arm 39 as indicated at 4! and is provided with a shoulder 42 which is held firmly against the inner surface of the arm 39 by a clamp screw 43, the underside of the head of which bears against the outer surface of the arm 39 and clamps the shaft or rod 4!] to the lever l8 for concurrent rocking motion therewith. A set screw 44 tapped into the arm 39 bears against the reduced portion 4! of the shaft 40 and aids in retaining the shaft :43 in fixed relation to the lever 18 after circular adjustment between the two hasbeen effected.

The arm 38 is provided with an enlarged opening 45 through which the shaft 43 projects. A torsion spring 46 encircles the shaft 40 within the recess 45 and has one end 41 anchored in a head 48 formed on the shaft 40 and its opposite end 49 anchored in an opening 53 formed in the body element I l. The spring 46 tends to rock the lever l8 and shaft 40 from the set position shown in Fig. 2 to the tripped position shown in Figs. 3 and l and the force of the'spring as exerted against the lever I8 may be minutely controlled by adjusting the shaft 43 in the lever l8 by rotating the one with respect to the other and thereafter tightening the holding screws 43 and 44.

The spring 43 normally maintains the end 3! of the lever 30 in contact with the shoulder 33 of the recess 32 in the guide plate 33 and said shoulder 36 normally prevents rocking of the lever l8 from the "set position to the tripped" position. V

The upper end 3| of the lever '30 is normally retained in contact with the shoulder 35 while the lever I8 is in the set position by a torsion spring 5| which encircles the shaft 20 within a recess 52 formed in the outer end'of the boss or bearing |9. One end 53 of the spring 5| is anchored in an opening 54 formed in the base of the recess 52 while the opposite end 55 of the spring 5| is anchored in a corresponding opening formed in the collar 29. The force exerted by the spring 5| in a direction to keep the upper end 3| of the lever 30 in contact with the shoulder 35 of the plate 33 may be minutely regulated by turning the collar 29 with respect to the shaft 20 and thereafter securing the collar rigidly to the shaft by tightening the set screw 56 which is threaded into the collar 29.

From the above it will be clear that when the finger 2| is in the set position shown in Fig. 2 the upper end 3| of the lever 30 is held firmly in contact with the shoulders 35 and 36 of the recess 32 formed in the plate 33 by the combined efforts of the springs 46 and 5|. It will also be apparent that relative rotation between the plate l and the cylinder I or the dial 3 will cause the finger 2| to travel around the needles 3 and I or vice versa and should any obstruction be presented to the lower end 22 of the detector finger 2| during such relative rotation the finger 2| will swing about the axis of the shaft 20 in the direction of the arrow 3 Fig. 1 thereby rotating the shaft 20 and the lever 3|) and causing the upper end 3| of said lever to slide along the shoulder 36 out of contact with the shoulder 35 until the point of intersection between the surface of the shoulder 36 and the edge 31 of the cam plate 33 is reached, such action taking place in opposition to the spring 5! When the upper end 3| of the lever 30 moves ofi the shoulder 36 the spring 46 then becomes effective to swing the lever |8 upwardly in the direction of the arrow 2, Fig. 1. Such movement of the lever It causes the upper end 3| of the lever 30 to slide along the inclined surface 31 of the fixed guide plate 33 thereby causing a further rotary movement of the shaft 28 in the direction of the arrow y, Fig. l.

The above noted universal movement of the detector finger 2| causes the lower end 22 of said finger to be immediately removed from contact with the obstruction by which the tripping of the device has been effected.

The pivot shaft 4|] is provided with a laterally extending pin or other protuberance 51 which lies in a vertical slot 58 formed in the rear face i2 of the body element II. This protuberance 51, in the present instance, constitutes one element of an electrical circuit breaker or switch, the second element of which, in the present instance, is in the form of a thin flexible blade 60.

The blade 63 constitutes a relatively fixed contact element of the switch and is rigidly secured at its upper end to a binding post 6| which is mounted in an insulating sleeve 62. The lower end of the blade 69 projects below the sleeve 62 to provide for flexing of the blade. The insulating sleeve 62 is secured by a nut 63 in an opening formed in the upper end of the body element One end of an electrical conductor 65 is permanently secured to the outer end of the binding post 6| in any suitable manner, as by a screw 66. The conductor 65 is electrically insulated from any and all other parts of the element H and the mechanism carried by the element The conductor 65 may be connected to one side of the coils of the stop motion trip motor M, as shown in Fig. 8. The opposite side of the motor coils may be connected to one side of a suitable current supply circuit. The second side of the current supply circuit may be connected to the machine proper, which forms one side of the stop motion circuit and includes the plate I ll, the foot 25, and body element The shaft 20 and the collar 29 thereon, being in electrical contact with the lever l8, and the lever l8 being in electrical contact with the rock shaft 40, carries the current of the second side of the stop motion circuit to the protuberance 51. The protuberance 5'l'functions as the movable contact element of a switch, of which the relatively fixed contact element is formed by the blade 60.

Rocking of the shaft 4|! in opposite directions brings the switch element 58 into and out of electrical contact with the switch element 60 and completes or interrupts the circuit through the trip motor M.

When the detecting finger 2| is engaged by a faulty needle or snarled thread, said detector finger is swung thereby from the set position shown in Figs. 2 and 5 to the tripped position shown in Figs. 1 and 3, wherein the protuberance 58 engages and makes electrical contact with the switch blade 60, thus completing the trip motor circuit, by which stopping of the machine is effected immediately.

The device may be reset by merely pressing the outer end of the lever B downwardly against the action of the spring 46, which causes the upper end 3| of the lever 30 to ride outwardly along the cam edge 31 of the guide plate 33 until the lever end 3| snaps across the shoulder 36 into contact with the shoulder 35, by action of the spring 5|.

.From the above it will be clear'that the device is of simple rugged construction and is very effective in, quickly stopping the machine to which it is attached, without necessity of the finger 2| moving to any material extent relative to the needles after the lower end 22 of the detector finger 2| engages any sort of an obstruction in its path. By swinging upwardly when tripped the detector finger 2| is carried away from the obstruction, leaving the same clear for removal by the operator when the machine stops.

I claim:

1. In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted to be normally positioned adjacent the needles of a knitting machine for movement laterally with respect thereto in a path adjacent said needles during normal operation of the machine, means supporting said finger for pivotal movement in a vertical plane substantially coincident with said path, and means supporting said finger for pivotal movement in a vertical plane transverse to said path.

2. In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted to be normally positioned adjacent the needles of a knitting machine for movement laterally with respect thereto in a path adjacent said needles during normal operation of the machine, means supporting said finger for pivotal movement in a vertical plane substantially coincident with said path, means supporting said finger for pivotal movement in a vertical plane transverse to said path, and an electric circuit controlling device operable by the pivotal movement of said finger in one of said planes.

3. In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted to be normally positioned adjacent the needles of a knitting machine for movement laterally with respect thereto in a path adjacent said needles during normal oper ation of the machine, means supporting said finger for'pivotal movement in a vertical plane substantially coincident with said -path,;-means supportingsaid finger for pivotal movement in a vertical plane transverseto said path and'an electric circuit controlling device operable by one and controlled by the other of said pivotal movements of said fingen 4. In anobstruction detector for knitting machines, the combination of a detector finger have ing one end adapted to be normally positioned adjacent the needles of a knitting machine for movement laterally :with respect thereto in a path adjacent said needles during normal-operation of .themachine, means supporting said finger for pivotal movement in a plane substantially coincident with said path, means supporting said finger for pivotal movement in a plane transverse to said path, an electric circuit controlling device operable by one and controlled by the other .of said pivotal movements of said finger and comprising a contact carried by one of said supporting means and a contact operatively connected to said finger for movement relative to the first said contact by rocking movement of said finger.

5. In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted to be normally positioned ation of, the machine, a rock shaft supporting said finger for rocking movement in avertical plane substantially coincident with said path, a lever supporting said rock shaft for rocking movement of said finger in a vertical plane transverse to said path, a body element mounted adjacent said path, and a rock shaft pivotally mounted in said .body element with said lever mounted on said last rockshaft.

a 9. In an obstruction detector for knitting machines, the combination of a detector fingerhaving one end adapted to be normally positioned adjacent the needles of a knitting machine for adjacent theeneedles of a knitting machine for V movement laterally with respect thereto 'in a path adjacent said needles during normal oper ation of the machine, means comprising a rock shaft and mounting for supporting said finger for pivotal movement in a vertical plane substantially coincidentwith said path, and means comprising a second rock shaft and mounting for supporting said finger for pivotal movementin a vertical plane transverse to said path; I

6. In an obstruction detector for knitting machines, the combination of a detector finger having one endeadapted to be normally positioned adjacent the needles of .a knitting machine for movement laterally with respect thereto in a path adjacent said needles during normal operation of the machine, means comprising a rock shaft and mounting for supporting said finger for pivotal movement in a plane substantially co-, incident with said path, means comprising a second rock shaft and mounting for supporting said finger for pivotal movement in a plane trans- Verse to said path, an electric circuit controlling device comprising a contact carried by one of said mountings, and a contact carried by the rock V shaft associated with the last said mounting and operable by the rocking of the shaft relative to the mounting.

-'Z.- In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted. to be normally positioned adjacent the needles of a knitting machine for movement laterally withrespect thereto in a path adjacent said needles during normal operation of the machine, a rock shaft supporting said finger for rocking movement'in a vertical plane substantially coincident with said path, a lever supporting said rock shaft for rocking movement of said finger in a vertical plane transverse to said path, and means pivotally supporting said lever adjacent said path.

8. In an obstruction detector for knitting machines, the combination of a detector finger having one end adapted to be normally positioned adjacent the needles of a knitting machine for emovement laterally with respect thereto in a path adjacent said needles during normal oper-" movement laterally with respect thereto in a path adjacent said needles during normal operation of the, machine, a rock shaft supporting said finger for rocking movement in a plane substantially coincident with said path; a lever supporting said rock shaft for rocking movement of said finger in a plane transverse to said path, a body element mounted adjacent said path, a rock shaft pivotally mounted in said body element with said lever mounted on and locked to said last rock shaft, a fixed contact carried by said body element, and a movable contact carried by ,the'rock shaft mounted in said body element and operable With respect to said fixed contact by rocking'of said lever. V

10, In an obstruction detector for a knitting machine provided with a series of needles havinghook-ends arranged in a circle, the combination of adetector finger adapted to have one end normally disposed adjacent said needles for concentric relative rotation between the finger and the needles about the axis of said circle, means for supporting said finger forsaid relative rotation including a body element, a rock shaft carried by said body element with the axis of the rock shaft disposed at right angles to a plane coincident with and extending radially from the' axis of said:circ1e, a lever secured to said rock shaft,. a second rock shaft carried by said lever with its-axis at right angles to the axis of the first said rock shaft, said finger being secured to said second rock shaft in spaced relation to the axis of said first rock shaft, a retaining plate carried by said body element, a retaining lever on said finger supporting rock shaft normally engaging a shoulder on said retaining plate, and resilient means normally maintaining said retaining lever in contact with said shoulder for maintainingsaid finger in said normal position.

11. In an obstruction detector for a knitting machine provided with a series of needles having hook ends arranged in a circle, the combination of a detector finger adapted to have one end normally disposed adjacent said needles for con- 7 centric relative rotation between the finger and the needles about the axis of said circle, means for supporting said finger for said relative rotation including a body element, a rock shaft carried by said body element with the axis ofthe 7 ders on saidepl'ate, resilient means retaining said lever in contact with said shoulders, and a cam surface on said plateadjacent one of said shoulders for engagement by said retaining lever upon release from said shoulders for additionally rocking said finger supporting shaft after initial rocking thereof by an obstruction which effects release of said retaining lever from said shoulders.

12. In an obstruction detector for a knitting machine provided with a series of needles having hook ends arranged in a circle, the combination with its axis at right angles to the axis of the first said rock shaft, said finger being secured to said second rock shaft in spaced relation to the axis of said first rock shaft, a retaining plate carried by said body element, a retaining lever on said finger supporting rock shaft, a pair of shoulders on said plate, resilient means retaining said lever in contact with said shoulders, a cam surface on said plate adjacent one of said shoulders for engagement by said retaining lever upon release from said shoulders for additionally rocking said finger supporting shaft after initial rocking thereof by an obstruction which effects release of said retaining lever from said shoulders, a fixed contact carried by said body element, and a movable contact carried by said lever supporting rock shaft for engagement with the fixed contact as a result of initial rocking of said finger.

' ALFRED CRAWFORD.

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