US3554239A - Shuttleless loom weft control device - Google Patents

Abstract

A shuttleless loom weft control device comprises, for each weft, a rocking lever whose position is determined by the advance of the weft during its insertion, having a thread tightener at one end for this purpose. At the other end of the lever is a permanent magnet facing which are situated, for the two extreme positions of the lever, magnetic blade switches connected respectively to two working and resting contacts of a weft thread selector. The lever cooperates with a switch whose successive openings and closings are synchronized with the motion of the loom. The movement of the lever is cam- or electromagnetgoverned so that the lever is free to rock during the second part of the thread drawing. The loom-synchronizing switch comprises a magnetic rotating pastille or a cam coordinated with the lever cam. The weft thread selector has a thread selector element for each weft thread and each has a permanent magnet which closes one or other of the working and resting contacts.

Description

United States Patent [72] lnventor Michel Gabet Montigny en Cambraisis, France [21] Appl. No. 739,697 [22] Filed June 25, 1968 {45] Patented Jan. 12,1971 [73] Assignee Fatex Lyon (Rhone), France [32] Priority June 30, 1967 [33] France I [31] No. 112,685

[54] SHUTTLELESS LOOM WEFT CONTROL DEVICE 10 Claims, 14 Drawing Figs.

[52] US. Cl 139/122, 139/370: 66/163 [51] Int. Cl D03d 47/34. 1 D03d 51/34 [50] Field of Search 139/122, 370; 66/157, 158, 163

[56] References Cited UNITED STATES PATENTS 3,092,150 6/1963 Brimans et al. 139/370 3,272,239 9/1966 Ancetetal.

ABSTRACT: A shuttleless loom weft control device comprises, for each weft, a rocking lever whose position is determined by the advance of the weft during its insertion, having a thread tightener at one end for this purpose. At the other end of the lever is a permanent magnet facing which are situated, for the two extreme positions of the lever, magnetic blade switches connected respectively to two working and resting contacts of a weft thread selector. The lever cooperates with a switch whose successive openings and closings are synchronized with the motion of the loom. The movement of the lever is camor electromagnetgoverned so that the lever is free to rock during the second part of the thread drawing. The loom-synchronizing switch comprises a magnetic rotating pastille or a cam coordinated with the lever cam. The weft thread selector has a thread selector element for each weft thread and each has a permanent magnet which closes one or other of the working and resting contacts.

PATENTED'JAN 12197:

sum D3UF12 PATENIED JAN 1 2 1971 SHEET Uh HF 12 PATENTEDJANIZIHII 3.554.239

sum new-12 PATENTEU Arnzlsn 3554239 sum 07 0F 12 PATENTEU A 1 21 1' 3; 554} 239 SHEET us [1F 12 PATENTEDJANIZIQW 35 4. 239

SHEET 12 0F 12 present invention is characterized in that it comprises, for

each weft thread, a rocking lever the position of which is determined by the advance of the correspondingweft thread at the moment of its insertion, one of the ends of this lever comprising for this purpose a thread tightener and atits other end, a permanent magnetfacing which are situated, for the two extreme positions of said lever, two magnetic blade switches connected to contacts, working and resting, of a weft thread selector cooperating, with a switch the successive openings and closings of which are in synchronism with the movement of the loom. i

In one embodiment according to the invention, the control of each rocking lever is ensured by a cam of which the circular profile of one part of its circumference thereby ensures its liberation in the second part of the drawing of the thread, so that, in this second part, this lever is free to rock if it is drawn by its thread, the boss of this cam bringing .the said-lever back into its initial control position for the following cycle when the switch functioning in synchronism with the motion of the loom, is again open.

In another embodiment according to the invention, the switch whose successive openings and closings are in synchronism with the motion of the loom, is controlled by a FIG. 1 shows in section in side elevation an embodiment of a welt control device according to the invention having mechanical control by a cam and in the position corresponding to the second part of entrainment of the weft, which corresponds'also to the position in the case of an undesirable thread;

FIG. 2 is a view similar to the preceding one but in the position of the lever during the first part 'of the drawing of the weft,

which position corresponds alsoto that produced in thelcase of the broken weft;

FIG. 3 is a viewin elevation-of an assembly equipped .for a loom operating with multiple wefts;

FIGS. 4 and 5 are views respectively analogous to those of FIGS. 1 and 2, but in plan view from aboveof another'embodiment of a weft control device according to the invention having electromagnetic control;

FIG. 6 is a, sectional side view in elevation of the embodiment of-FIG. 5;

FIG. 7, 9, 11 and 13 are diagrammatic illustrations showing the general operation of the electromagnetic embodiment. respectively in the four situations which can occur; and

FIGS. 8, 10, 12 and Marc views respectively similar to the four preceding ones for the mechanical embodiment employing cams.

In the mechanical embodiment of FIGS. 1 to 3, in a housing 1 are mounted,'for free rocking around a horizontal shaft 2 as many levers 3 as the loom comprises weft threads 4 to be controlled and to be inserted selectively in the cloth. The positionmagnetic contact influenced by a magnetic pastille, turning in- I tegrally with the cam.

Thus, when one of the levers ing the thread and while the latter is not broken, the permanent magnet of the said levercloses the circuit of one of the two magnetic switches connected to the resting contacts of the selector and the magnetic pastille turning integrally with-the control cam of the corresponding lever comes to face its contact and closes it, but as the first switch' is not influenced by the magnet of the lever, this switch remains open and the electric current of the driving motor of the loom is not cut.

On the other hand, if the tread is broken, the lever does not rock at the end of the course of the pick and the first magnetic switch remains closed so that at thev rnoment when the magnetic pastille comes to face its contact, the latter cuts the current.

The same happens in the case where an undesirable neighboring thread is drawn in error with the thread, relating to a weft. In fact, in this case, the corresponding lever rocks and the first magnetic switch is opened but the second is closed, and, as it is in circuit by the erroneous entrainment of the thread, the 'contact, ensured by the turning magnetic pastille, stops the driving motor of the loom.

As a variation, .each rocking lever is-de'pendent on an electromagnet which is not fed in the second part of the drawing of the thread, so that, in this second part, this lever is free to rock if it is drawn by its thread, the electromagnet being 'again fed after the end of the drawingof the-weft tobring this lever-back into its initial control position for the following cycle, as soon as the switch functioning in synchronism 'with the movement of the loom is again open.

Also as another-variation, the switch whose openings and closing are in synchronismwith the motion of theloom, is constituted by two blades one of which is positivelycontrolled by a cam.

The operation of this latter control system by an electromagnet,--is identical with that previously described for the mechanical control system by a cam.

In order that the invention may be'more fully understood there are now described in more detail the aforesaid 'various embodiments purely by way of nonlimiting' example with reference to the accompanying drawings in which:

rocksin the direction of drawing of these levers axially on their shaft 2 is ensured by means of stop rings 5 (FIG. 3).

Each of these levers 3 bears at its upper part a thread tensioner constituted, in knownmanner, by a set of cups 6 urged into contact with one another, by a spring 7 of adjustable tension, and between which slips the thread which, upstream and downstream of this tensioner, passes under guides 8.

i Each of the levers 3 is'equipped with a follower 9 which slides over a cam 10 and the assembly of all these cams is fixed on a shaft 12 the rotation of which is controlled, in synchronism with the motion of the loom, by a bevel gear '13 from a cardan transmission 14.

At its lower end, each of the aforesaid levers 23 is provided with a magnet 15 coming into position for the two end posipassing, during its rotation, in front of a magnetic-contact 20 inserted in the circuit of theaforesaid magnetic blade switches 16 and 17. The operation of the cams 1-0 is such that during the first part of the drawing of the thread 4, the bosses of.- the .cams.l0 action. againstfollowers 9 to rock the-leversto the position shown in FIG. 2, the switches-16 being therefore closed by reason of the presence of the permanentmagnets 15 which are positioned opposite themagnetic switchesl'6; on

- the other hand, in the last partof the drawing of .the thread-,4, the boss of the cams 10 is withdrawn from the followenas shown in FIG. 1 which permits the levers to rockunder theactionwhich they canreceive from their thread during the-drawing of the latter and its slipping betweentthe cups,6, in which case the magnetic switch 17 is closed.

In the magnetic embodiment, of FIGS. 4 to 6, the same members are used with. the difference, however, that. the levers 3 are located in a horizontal plane, and the ,shaft 2 around which they .rock, is vertical. Moreover, thecontrolof these levers is not ensured mechanically by a cam, but, for each lever there is an electromagnet 22 which is only fed with current during the first part of the drawing of the thread4.

On the other hand, each lever 3 comprises a small ,angle bracket 23 which is selectively displaced by ahinged flap,2 4.of its respective electromagnet 22 as best seen in FIGS..4,' Sand 7. The flap 24 is subjected to the action of a spring-25 urging the flap to an extended position as shown in FIGS. 4 and 7. The electromagnet when energized, pivots the flap 24 inwardly against the opposite of spring 25 and the flap engages angle bracket 23 to pivot the same about shaft 2 as shown in FIG. 5. The magnetic switch 19, 20 of FIGS. 1 to 3 is replaced by a mechanical switch controlled in synchronism with the motion of the loom. This switch is constituted by two blade contacts 26 of which one is actuated mechanically by a cam 27 (FIG. 7)

As regards this electromagnetic arrangement of FIGS. 4 to 6, each of the electromagnets 22 is only energized as indicated hereinbefore, during the first part of the drawing of the thread 4. In the first part of the drawing of the thread, the flap 24 of the electromagnets 22 is retracted and the angle bracket 23 is fixed on the corresponding lever 3 is correspondingly retreated as shown in FIG. 5. The magnet of these levers is then opposite the magnetic blade switch 16 and thereby ensures its closing. On the other hand in the last part of the drawing of the thread, a cam 31 opens a switch 30 and electromagnets 22 are no longer energized. The flaps 24 are urged by their springs 25 away from brackets 23 and therefore free the levers 3 enabling the latter to rock under the action which they can receive from the thread during the drawing of the latter and of its sliding between the cups 6 in which case, the magnetic blade switch 17 is closed.

For the case of the electromagnetic embodiment (FIGS. 7, 9, 11, 13) the energization of electromagnets 22 is obtained from the output of an alternating current transformer 29. This supply is controlled, as indicated above, by a switch 30 controlled by a cam 31, turning in synchronism with the movement of the loom.

In the circuit is inserted a rectifier 32 which has the simple function of enabling the use for the electromagnets 22, of reels of small dimension and to reduce the wear of the flaps 24 by suppressing vibrations.

Finally whether it relates to one or other of the aforesaid arrangements (FIGS. 1, 2, 3, 8, 10, 12, 14) or (4, 5, 6, 7, 9, 11, 13), the apparatus comprises, besides the properly so-called weft stop motion shown symbolically at 34, a selector 35 comprising as many thread selector elements (screw plates) 36 as threads 4 to be controlled, each selector elements being equipped with a permanent magnet 37 positioned, according as the selector element is lowered or raised by its control lever 38 in front of a magnetic switches 39 and 40. The closing of the circuit to the ground 41 is established by a common point 42 situated between these two latter contacts.

The general operation of this weft stop motion is the following for the four cases which can occur, it being specified that all the explanations related here, concern the position of the assembly of members in the last part of the drawing of the thread of the weft which arrives at the controller 34 under a slight tension resulting from the action of any braking system (not shown).

1. Case of normal advancing of the weft thread desired being still suitably drawn and not being broken (FIGS. 7 and In the case of the electromagnet embodiment (FIG. 7) the electromagnet 22 is no longer energized, the cam 31 having opened the switch 30. The pressure exerted by the cups 6 on the thread 4 (which is displaced in the direction of the arrow) causes the lever 3 to be rocked so that its magnet 15 is facing the magnetic switch 17 to close the same while the magnetic switch 16 is open. On the other hand, the selector element 36 being lowered, its magnet 37 is opposite-switch 39 and closes it, The switch 40 being open. On the other hand, the cam 27 having closed switch 26, the current which arrives at the common point 43 passes by the magnetic switch 17 and is directed to the selector 35 where it arrives at the contact 40 which, being open, prevents its passage. There is, therefore, no signal and the loom continues to operate.

In the case of the mechanical embodiment (FIG. 8) the operation is the same, the magnet 15 having closed the magnetic switch 17 and the magnetic pastille 19 having closed the switch 20.

2. Case where the weft thread is held waiting without being either drawn or broken (FIGS. 9 and 10) In the case of the electromagnet embodiment (FIG. 9) the lever 3 which has been previously retracted by the electromagnet 22 and which is freed in the second part of the drawing of the thread, due to the deenergization of this electromagnet, the lever 3 is freed but it remains in place since it is not drawn by the thread. The magnet 15 remains therefore opposite the magnetic switch 16 and closes it. From the common point 43 the current passes by this switch 16 and arrives at the switch 39 of the selector, but the selector element 36 is not lowered. Its magnet 37 is not therefore opposite the switch 39 so that the latter is open and does not permit the passage of current. As in the preceding case l there is no signal and the loom continues to operate, the weft thread being held waiting,

not having been selected.

In the case of the mechanical embodiment (FIG. 10) the operation is the same. In fact, the lever 3 having remained in place, the magnetic switch 16 is closed by the magnet 15 and the switch 20 is itself closed by the magnetic pastille 19.

3. Case in which the weft thread which has been selected has broken and thus is no longer drawn (FIGS. 11 and 12) In the case of the electromagnetic embodiment (FIG. 11) the lever 3 which has been retracted by the electromagnet 22 in the first part of thread drawing, is freed since electromagnet 22 is not supplied, the opening of this circuit having been obtained in the second part of the drawing of the thread by the cam 31. The lever 3 is therefore free and since it is not longer subject to the traction of the thread as the latter has broken, the lever remains immobile, its magnet 15 remaining opposite the magnetic switch 16 which it closes. From the common point 43 the current therefore passes this switch 16 and arrives at the switch 39 of the selector 35. This contact being closed by the presence of the magnet 37 of the selector element 36 which is lowered, the current passes and arrives at the common point 42 and, from there, to the ground 41. Therefore a signal is produced and the loom is stopped.

The operation is established in the same manner in the case of mechanical control by cam (FIG. 12). In fact, the lever 3, not having been brought back by the traction of the thread, remains in the position that has been given to it by the boss of the cam 10 and the magnet 15 of lever 3 closes the magnetic switch 16.

4. Case of an undesirable thread (FIGS. 13 and 14) In the case of the electromagnetic embodiment (FIG. 13) the lever 3 which has been freed by the electromagnet 22 tilts when an undesirable thread advances since it is drawn and the permanent magnet 15 of the said lever closes the magnetic switch 17.

From the common point 43 the current passes therefore through switch 17 and arrives at the selector 35 up to the input of the switch 40. The selector element 36 not being lowered, this contact is closed by the magnet 37 and the current passes therefore to the common point 42, and, from there, to the ground 41. Therefore a signal is produced and the motor is stopped.

In the case of the mechanical embodiment (FIG. 14) the operation is established in the same manner, the current passing the switch 20, the switch 17 and the switch 40 all of which are closed.

It will be apparent that various changes and modifications may be made in the embodiments hereinbefore described without departing from the essential concept of the invention as defined in scope by the appended claims.

Iclaim:

1. Weft selecting and detecting apparatus for shuttleless loom, said apparatus comprising, for each weft thread, a lever supported for free pivotal movement about an axis of rotation. a tensioning device on said lever engaging the associated weft thread, means acting on said lever to displace the same to a first limit position, said lever being displaced to a second limit position by the tension in the thread with said means inoperative, a permanent magnet on said lever, two magnetic blade switches positioned to face the permanent magnet on said lever in a respective limit position, a weft selector comprising a selector element for each thread weft, and switch means connected to the blade switches and controlled by the selector element to be shifted between first and second states, and a further switch connected to the blade switches and periodically opened and closed in synchronization with loom motion, said magnetic blade switches, switch means and further switch being connected in circuit for indicating the existence of thread breakage or the presence of an undesireable thread.

2. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises a rotatable cam with first and second portions sequentially in contact with the lever such that in a first part of the drawing of the associated weft thread the lever is in the first limit position and in a second part the lever is free to move to the second limit position under the tension in the thread.

3. Apparatus as claimed in claim.2 wherein said further switch comprises a magnetic contact, and a magnetic pastille coupled to and rotating with the cams to alternately pass in front of said contact to close the switch.

4. Apparatus as claimed in claim 2 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation. I

5. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises an electromagnet which is energized in a first part of the drawing of the associated weft thread to displace the lever to its first limit portion and is deenergized in a second part of the drawing of the thread so that the lever is free to move to its second limit position under the tension in thethread.

6. Apparatus as claimed in claim 5 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.

7. Apparatus as claimed in claim 5 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.

8. Apparatus as claimed in claim 1 wherein said further switch comprises a fixed magnetic contact and a magnetic pastille driven with said means which displaces the lever to alternately pass in front of said contact to close the switch.

9. Apparatus as claimed in claim 1 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.

10. Apparatus as claimed in claim 1 wherein said switch means comprises open and closed switches which are al ternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.

Claims (10)

1. Weft selecting and detecting apparatus for shuttleless loom, said apparatus comprising, for each weft thread, a lever supported for free pivotal movement about an axis of rotation, a tensioning device on said lever engaging the associated weft thread, means acting on said lever to displace the same to a first limit position, said lever being displaced to a second limit position by the tension in the thread with said means inoperative, a permanent magnet on said lever, two magnetic blade switches positioned to face the permanent magnet on said lever in a respective limit position, a weft selector comprising a selector element for each thread weft, and switch means connected to the blade switches and controlled by the selector element to be shifted between first and second states, and a further switch connected to the blade switches and periodically opened and closed in synchronization with loom motion, said magnetic blade switches, switch means and further switch being connected in circuit for indicating the existence of thread breakage or the presence of an undesireable thread.

2. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises a rotatable cam with first and second portions sequentially in contact with the lever such that in a first part of the drawing of the associated weft thread the lever is in the first limit position and in a second part the lever is free to move to the second limit position under the tension in the thread.

3. Apparatus as claimed in claim 2 wherein said further switch comprises a magnetic contact, and a magnetic pastille coupled to and rotating with the cams to alternately pass in front of said contact to close the switch.

4. Apparatus as claimed in claim 2 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.

5. Apparatus as claimed in claim 1 wherein said means acting on said lever comprises an electromagnet which is energized in a first part of the drawing of the associated weft thread to displace the lever to its first limit portion and is deenergized in a second part of the drawing of the tHread so that the lever is free to move to its second limit position under the tension in the thread.

6. Apparatus as claimed in claim 5 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.

7. Apparatus as claimed in claim 5 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.

8. Apparatus as claimed in claim 1 wherein said further switch comprises a fixed magnetic contact and a magnetic pastille driven with said means which displaces the lever to alternately pass in front of said contact to close the switch.

9. Apparatus as claimed in claim 1 wherein said further switch is constituted by two blades and comprising a cam positively controlling one of said blades to open the further switch.

10. Apparatus as claimed in claim 1 wherein said switch means comprises open and closed switches which are alternately operated and a permanent magnet on each selector element adjacent the open and closed switches for controlling the states thereof in alternation.

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