US2675029A

US2675029A - Weft stop motion device for looms for weaving tufted pile fabrics

Info

Publication number: US2675029A
Application number: US150271A
Authority: US
Inventors: Edward S Butler; Sutcliffe Arthur
Original assignee: Platt Brothers and Co Ltd
Current assignee: Platt Brothers and Co Ltd
Priority date: 1949-03-17
Filing date: 1950-03-17
Publication date: 1954-04-13
Anticipated expiration: 1971-04-13

Description

fii fil'lfi T954" E s. BUTLER ET AL 2,675,029

WEFT STOP MOTION DEVICE FOR LOOMS FOR WEAVING TUFTED PILE FABRICS Filed March 17, 1950 3 Sheets-Sheet l April 13, 1954 E. s. BUTLER ET AL WEFT STOP MOTION DEVICE FOR LOOMS FOR WEAVING TUFTED FILE FABRICS 3 Sheets-Sheet 2 Filed March 1'7, 1950 TORI.- jdf/sr 1412 510" Gal/c2229! QZM V April 13, 1954 E s. BUTLER ET AL 2,675,029

WEFT STOP MOTIONDEVICE FOR LOOMS FOR WEAVING TUFTED PILE FABRICS Filed March 1'7, 1950 3 Sheets-Sheet 3 Patented Apr. 13, 1954 WEF'i. STOP MOTION DEVICE FOR LOOMS FOR WEAVING TUFTED PILE FABRICS Edward S. Butler, Chadderton, Oldham, and Arthur Sutclifle, Werneth, Oldham, England, assignors to Platt Brothers and Company Limited, Oldham, England Application March 17,1950, Serial No. 150,271

Claims priority, application Great Britain March 1'7, 1949 Claims.

This invention of improvements in weft stop motion devices for looms for weaving tuft pile fabric refers to weft stop motion devices for spool Axminster carpet looms in which the weft threads are carried by needles projected across the warp space of the loom.

In a loom of the type referred to as usually constructed the strands of weft each pass through a guide eye on a feeler finger pivoted on a knockoff lever at the needle end of the loom.

In this construction when a weft breaks the respective feeler finger tilts by gravity into a position in which a block on the lower end of the finger is moved into the path of movement of a trigger in operative association with th knockoff lever of the loom.

The aforesaid trigger is moved into its operative position only when the needle is retracted out of the Warp shed.

When the said finger falls the trigger presses against the block on the finger and causes the knock-oh? lever to be rocked about its pivot to operate the stop motion of the loom, i. e. to knock out the clutch and apply the brake to stop the loom.

In the present invention the feeler fingers carrying the guide eyes through which weft passes are each pivotally mounted on a bracket attached to the frame of the loom at the needle end. A. contact plate or a series of plates is attached to the said bracket adjacent to the feeler fingers, the said plate or plates being insulated from the bracket and forming one terminal point in a low-voltage electric circuit the other terminal of which is provided by the feeler fingers through the medium of the loom frame.

When a weft thread breaks the respective ieeler finger trips and falls into contact with the aforesaid contact plate but the electric circuit is not completed until a sequence switch is put into operative position as the needles reach their re tracted position, and are conveniently situated for re-thrcading. The sequence switch is incorporated in the aforementioned circuit and may be operated by a cam called a weft feeler cam, which is adapted to make one revolution in each complete cycle of operations of the loom.

Completion of the lowwoltage electrical circuit brings the stop motion into operation whereupon the loom is brought to a standstill.

In a modification of the invention as applied to a narrow spool Axminster carpet loom, the feeler fingers are constructed and operate in similar manner to the ieeler fingers previously described,

but the sequence switch instead of being operated by the weft feeler cam is operated by the needle operating lever.

The aforesaid switch embodies two contacts which are only closed when the cam or the needle operating lever is in the position occupied when the cam or the needles are out of the shed.

The invention will now be described with reference to the accompanying drawings in which only so much of a loom is shown as is necessary for a clear understanding of the invention.

Fig. 1 i a front elevation of needle operating mechanism of a spool Axminster carpet loom with one part of the invention applied thereto; Fig. 2 is a fragmentary side elevation of feeler finger mechanism according to the invention; Fig. 3 is a plan view of Fig. 2 looking in the direction of the arrow A. Fig. 4 is a front view of Fig. 2; Fig. 5 is a diagram of the electrical circuit of the electric stop motion mechanism; Figs. 6 and '7 are diagrammatic views of a detail part of the invention used only in connection with a carpet loom weaving narrow fabric. Fig. 8 is a fragmentary view of a detail part of the invention later to be described.

Referring to Fig. 1 of the drawings [0 indicates the needles, H the needle arm, l2 the connecting rod and I3 the crank for operating the needle motion mechanism, and M the frame of the loom, all of known construction and operation.

Referring to Figs. 2, 3 and 4 there are located adjacent to the needles I 0 feeler fingers [5, there being a feeler finger for each thread being inserted by the needles. The feeler fingers !5 are carried by a block 16 pivotally mounted in a bracket I! secured to the frame M of the loom. Secured to but insulated from the bracket [1 are contact plates 18 providing a contact for each feeler finger I5, the contact plate l8 formin a contact terminal in a low-voltage electric circuit, th other contact of which is provided by a feeler finger through the medium of the loom frame. The method of insulating the contact plate 18 is indicated at H! in Fig. 2.

Each feeIerfinger I5 is furnished with a guide eye 20 through which the weft passes.

Referring now toFig. 1, there is provided adjacent to the lower end of the needle operating lever II, a switch 2| hereinafter referred to as a sequence switch, embodying two contacts 22. 23 which are only closed when the needle operating lever II is in the position occupied when the needles are out of the shed, i. e., as shown in Fig. 1. I

Referring to Fig. 8 which shows a sequence switch operated by a cam instead of by the needle operating arm ll, 24 indicates a cam secured on a shaft 25 mounted in the loom frame and adapted to make-one revolution in each complete cycle of operations of the loom. Located adjacent to the cam 24 is a sequence switch 26 having two

contacts

21, 28. The cam 24 is so set as to operate the switch only when .the needles are out of the shed.

The

contacts

21, 28 are adapted to be bridged by a plunger 29, operated by a bowl or roller 33 mounted on a lever 3| pivoted on the switch casing, said lever also being furnished with -a bowl or roller 32 tracking the cam 24. When the cam 24 depresses the lever 31 :the plunger 29 is pressed inwards to bridge the

contacts

27, 28 and complete the low-voltage circuit. When the cam moves round, the plunger 29 is moved outwards under spring pressure to open the

contacts

21, 28.

When a weft thread breaks the respective feeler finger I falls into contact with the contact plate It but the electric circuit is not completed until the sequence switch is put into operative position as the needles reach their retracted position.

This delay, in completing the circuit enables the needles to be withdrawn from the warp space before the loom is stopped should the thread break when the needles H] .are in the warp space thereby facilitating re-threading of a needle.

The sequence of operations of the electric stop motion will be described with reference to the diagram shown in Fig. 5, in which E indicatesa transformer for low (safe) voltage; C indicates a trip relay with one normally closed contact indicated at C D indicates a relay with two normally open contacts D D E indicates a trip contact on the loom; F indicates a change-over push unit actuated by the loom starting handle, having four terminals F F F and F G indicates a reset button on the loom; I-I indicates a signal lamp. J indicates a sequence switch.

The operation is as follows:

With the loom running normally, all the contacts and relays are as shown in the diagram, the feeler fingers 15 being held in operative position by the threads. When a thread breaks and the respective fceler finger drops on to the contact'plate [8, i. e. closing trip contact E of the diagram, but the electric circuit is not completed until the sequence switch J is closed,.thus energising the relay coil D and closing contacts D D contact D providing an alternative path for electric current through the relay coil D, the relay coil D self-retaining and now independent of the contact at E. The contact D being closed provides a circuit through the contacts F F and relay coil C, thus breaking contact C which causes the circuit to the electrornotorto be opened automatically when the sup.- ply voltage fails and thereby stops the loom.

The relay coil is now tie-energised and C returns to normal closed position. An alternative circuit then flows through contacts F F lamp H and contact D thus indicating the cause of the stoppage. In the case of the application of the electric stop motion to a carpet loomweaving. narrow fabric the breaking of contact C causes the circuit to the electromotor to be opened automatically when the supply voltage fails and so de-energises a solenoid on the loom,

whereby. to trip the starting handle.

7 The starting handle, which is springloaded, thus returns to the off position and in so doing releases the clutch between the electromotor and the loom and applies a mechanical brake, at the same time also releasing the change-over push unitF, -breaking contact between F and F and bridging F and F The relay coil is now de-energised and C returns to normal closed position. An alternative circuit then flows through contacts F F lamp 1-]? and contact D thus indicating the cause of the stoppage.

In either of those cases the driving motor can be switched on if required and the loom inched at the operators will, but, if the starting handle is moved to full on position before removal of the causes of stoppage, the stop motion will again act.

Having rectified the cause of the stoppage, the operator can then press the re-set button G, and the loom is again ready for running.

The means for moving the starting handle quickly from on position to ofi position are shown diagrammatically in Figs. 6 and 'Z.

Referring to Figs. 6 and '7, 33 indicates the starting handle shown in the on position in a notch 34 in a quadrant 35, see Fig. 7. 36 indicates a solenoid carried in suitable position on the loom; connected by a swivel 3'5 to the core 38 of the solenoid 36 is a bell-crank lever 35, the opposite end of which is connected to an adjustable connecting rod 40. The connecting rod 49 is connected at its opposite end by a lever M to a knock-cit lever 42 pivoted on the same shaft 43 as the lever M, the free end of the knock-off lever '42 lying adjacent to the starting handle 33 when in the on position. When the stop motion is actuated as previously described, the solenoid is de-energised, whereupon the core 38 drops and through the link 3? rocks the bellcrank lever 39 which in turnpushes the con necting rod in the direction of the arrow Y to" rock the lever 4| and with it the knock-cit lever t2 which, moving quickly forward under the influence of a spring lid in operative association with the connecting rod 48, knocks the starting handle 33 out of the notch 34.

The starting handle 38 which is S131lng-il7.- fluenced moves rapidly to the off position and releases the driving clutch between the electromotor and the loom and applies a brake to bring the loom to a standstill.

What we claim is: r

i. In a spool Axminster carpet loom in which the weft threads are carried by needles projected across the warp space of the loom and including a motor, a driving clutch, a starting handle and a brake, a weft stop motion device including a low voltage electrical circuit, feeler fingers having guide eyes through which weft passes, a bracket attached to the m frame at the needle end in which the said feeler fingers are pivotally mounted, contact plates attached to but insulated from the said bracket and each forming a terminal in said low-voltage electrical circuit of the stop motion device, there being a contact plate for each feeler finger whereby the respective feel-er finger makes contact with the respective contact plate in the absence of weft thread, the feelerfiipgers providing the other terminal in the said circuit through the medium of the loom' frame. 2. A Weft stop motion device as claimed in claim 1, including a needle-operating lever, a sequence switch located adjacent to the lower end of the needle-operating lever of the loom, said sequence switch comprising a casing, two contact terminals housed in said casing and connected in the low-voltage circuit of the stop motion device, a plunger slidably mounted in said casing, a spring surrounding said plunger to yieldingly urge it towards the said needle-operating lever, said plunger being adapted to be pushed inwards by the needle-operating lever when it reaches the position where the needles are fully retracted out of the warp space and in position for re-threading, whereby to bridge the said contact terminals and in conjunction with the contact made by a fallen feeler finger and the respective contact plate to complete the low-voltage circuit and thereby stop the loom.

3. A spool Axminster carpet loom as claimed in claim 1, in which the weft stop motion device embodies a low-voltage circuit including a transformer for low voltage, a trip relay with one normally closed contact, a relay with two normally open contacts, a change over push unit actuated by the loom starting handle and having four terminals, a reset button on the loom, and a signal lamp.

4. A spool Axminster carpet loom as claimed in claim 1, including a spring-influenced starting handle, a notched quadrant, a solenoid, a bellcrank lever connected at one end to said solenoid, a connecting rod attached at one end to the end of the ball-crank lever remote from the solenoid, a spring attached at one end to said connecting rod and at its opposite end to the loom frame. a pivoted knock-off lever positioned adjacent to said starting handle when said starting handle is in the on" position in the quadrant, and a lever connected between said connecting rod and said knock-off lever, whereby when the stop motion device is actuated the solenoid is deenergized and through the lever system the knock-off lever is caused to knock the starting handle out of the notch in the quadrant whereupon the starting handle under the influence of its spring moves quickly to the off position to release the driving clutch and apply the brake to bring the loom to a standstill.

5. A weft stop motion device as claimed in claim 1, further including a sequence switch comprising a casing, two contact terminals housed in said casing and connected in the low-voltage circuit of the stop motion device, a plunger slidably mounted in said casing, a lever pivoted on the switch casing, a bowl or roller rotatably mounted in said lever, a spring surrounding said plunger whereby the plunger is maintained in contact with the said bowl or roller, and a further bowl or roller also rotatably mounted in said lever, a shaft journalled in the loom frame, and a cam secured on said shaft adjacent to said sequence switch and tracked by said second-mentioned bowl or roller, said shaft being adapted to make one revolution in each complete cycle of operations of the loom, whereby when the cam depresses the said lever the plunger is pressed inwards to bridge said contacts and in conjunction with the contact made by a fallen feeler finger and the respective contact plate to complete the low-voltage circuit and thereby stop the loom, the plunger being moved outwards under pressure of the spring to open the contacts when the cam moves around.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,958,122 Robertson May 8, 1934 2,407,773 Fletcher Sept. 17, 1946