US3817292A

US3817292A - Apparatus for shedding in weaving looms

Info

Publication number: US3817292A
Application number: US00245143A
Authority: US
Inventors: P Doehler; E Baumgartner
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-20
Filing date: 1972-04-18
Publication date: 1974-06-18
Anticipated expiration: 1991-06-18
Also published as: FR2134060B1; DE2119053C3; IT951854B; DE2119053A1; DE2119053B2; CH548464A; BE782374A; FR2134060A1

Abstract

A shedding apparatus for a weaving loom has the warp threads thereof connected to corresponding electrical conductors located in a transverse magnetic field. Current is selectively directed to the conductors so that they selectively displace their associated warp threads to form a shed.

Description

United States Patent [191 Doehler et al.

[ June 18, 1974 1 1 APPARATUS FOR SI-IEDDING IN WEAVING LOOMS [76] Inventors: Peter Doehler, Kaulbachstrasse 59; Erich Rudolf Baumgartner, Tiroler Platz 4, both of Munich, Germany [22] Filed: Apr. 18, 1972 [21] Appl. No.: 245,143

[30] Foreign Application Priority Data Apr. 20, 1971 Germany 2119053 [52] US. Cl 139/55, 139/317, 139/319 [51] Int. Cl D03c13/00, D03c 19/00 [58] Field of Search 139/55, 59, 317, 319;

[56] References Cited UNlTED STATES PATENTS 983,862 2/1911 Regal 139/319 1,881,076 10/1932 Haebler 139/319 X 2,204,891 6/1940 Hamilton 139/55 3,103,953 9/1963 Lauri'tsen t 139/55 3,114,398 12/1963 Pfarrwaller 139/134 X FOREIGN PATENTS OR APPLICATIONS 901,396

1/1954 Germany 139/319 Primary Examiner-James Kee Chi Attorney, Agent, or FirmGriffin, Branigan & Butler ABSTRACT A shedding apparatus for a weaving loom has the warp threads thereof connected to corresponding electrical conductors located in a transverse magnetic field. Current is selectively directed to the conductors so that they selectively displace their associated warp threads to form a shed.

28 Claims, 9 Drawing Figures PAIENTEDJummn 3.817292 SHEET 1 [IF 4 PATENTEDM 18 I974 SHEET 2 0F 4 FIG. 3

23 WTFTFWTW I I APPARATUS FOR SHEDDING IN WEAVING LOOMS FIELD OF THE INVENTION This invention relates to means for shedding at weaving looms of any type.

BACKGROUND OF THE INVENTION It is known that, for shedding, there are used heddles which are provided with ears or loops and which are raised and lowered for forming a shed of the warp threads either united in groups, together with each other and in one andthe same directionby a shaft machine, or selectively individually by means of the Jacquard machine.

In the case in which the heddles are individually moved, the accommodation of the individual drive elements in as small a space as possible meets with difficulties especially in the case of great densities of the warp threads. That is why one has already arranged the individual heddles staggered in'longitudinal direction of the warp threads to be thereby able to enlarge the distance between the drive elements for the heddle to permit the accommodation of the structural elements required.

It is furthermore disadvantageous that known shedding means, due to the necessity of providing a-common drive source for all heddles, have a great inertia which'permits fulfilling of a control command only at restricted speed and thus limits the weaving velocity.

The object of the invention is to solve the problem of reducing the inertia of the driving means for moving the individual warp threads as well as the space requirement for the requisite drive elements.

SUMMARY OF THE INVENTION.

This problem is solved in that with each warp thread or with each group of warp threads to be always actuated in one and the same direction and simultaneously there is coupled at least one conductor which is feedable selectively with electrical current and which extends transversely of the intended direction of deflection of the threads, and in thatfor each respective group of these conductors or for all of these conductors there is provided a magnet which produces a magnetic field extending substantially transversely of the longitudinal direction of the conductors and transversely of the intended direction of deflection of the threads. Preferably the individual conductors arelocated parallel to the longitudinal direction of the warp threads, while for each warp thread to be moved there may be provided a plurality of conductors connected in series with respect to each other.

In this case, the series connected parallel conductors constitute part 'of a flat coil one of the coil sides of which cooperates with the magnets field when current is fed to the conductors. The opposite coil side opposes the magnets field and functions to limit the coils motion to a predetermined amount. In this manner, the

opposite coil side provides an electromagnetic abutment, so to speak.

According to a further advantageous embodiment of the invention, the individual flat coils may be arranged on a coil carrier consisting of magnetizable material so that a stack of coil carriers almost bridges over the space between the magnetic poles of the magnet and thus decreases the magnetic resistance of the magnetic circuit of this magnet and achieves induction values adequate for individual coil movement.

The connections to the individual conductors or to the coils can be produced according to methods which are known per se from the printed circuit art so that the individual conductors or coils can be arranged extremely closely adjacent each other and corresponding densities of warp threads can be achieved.

To all embodiments of the invention it is common that a driving force is produced for a predetermined warp thread in that an associated conductor located in amagnetic field has applied to it a voltage for producing a predetermined direction of current in this conductor corresponding to a control command so that this conductor undergoes a deflection in a known manner, the direction of which can be determined for example accordingto the right hand screw rule from one conductor to another. The deflection is transmitted either directly or by way of coupling. elements to an ear or loop or to a groove which imparts a corresponding movement to the associated warp thread. The driving force which acts on the individual warp threads and which must be adjusted to the tension of the warp thread is proportional to the intensity of the magnetic field, to the current intensity, eventually to the number of conductors used for each warp thread and fed with current, as well as'to the length of these conductors in the magnetic field. Hence by varying these parameters, it is possible to achieve a suitable driving force even though one of these parameters, for example the intensity of the magnetic field, is not deliberately variable.

Useful embodiments of the invention are subject matter of the attached claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be elucidated in greater detail in the light of a number of illustrative embodiments with reference to the attached drawings, in which FIG. 1 shows a schematical perspective view of an apparatus according to the invention,

FIG. 2 shows a sectional schematical side view of another embodiment of the apparatus according to the invention, i

FIG. 3 is a perspective schematical view of a further.

embodiment of the invention,

FIGS..3a, 3b and 3c show partial schematical views of details of the apparatus according to FIG. 3,

FIG. 4 is a 'greatly simplified sectional side view of an embodiment which is a modification of that according to FIG. 1,

FIG. 5 is a side view of an additional device utilizable in conjunction with the embodiment according to FIG. 3, and

FIG. 6 is an embodiment which is a modification of that according to FIG. 3 and which is shown in a greatly simplified mode of representation.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION In FIG. 1 are shown a few warp threads 1 to 6 guided through ears or loops 7. Whereas the ears associated with the

warp threads

1, 2 and 3 are lowered so far that these warp threads extend substantially in straight lines, the ears 7 associated with the warp threads 4, S and 6 are raised so far that the last-mentioned warp threads together with the

warp threads

1, 2i and 3 define a high shed into which the shuttle indicated schematically at 8 can be shot. The warp beam,goods piece beam and the reed are omitted in the drawing for the sake of simplicity.

The ears 7 are coupled via heddles or rods 9 to current conductors 10 which are each associated therewith and which are tensioned between a grounded busbar 11 and terminals 12 selectively connectable by way of pairs of switches13 and 14 respectively to a busbar of negative voltage or to a busbar of a

positive voltage

15 or 16 respectively.

The current conductors 10 extend along a substantial length portion of their total length between the busbar 11 and the terminals 12 within an intense magnetic field which is produced by the

pole shoes

17 and 18 of a magnet as shown schematically in FIG. 1, and which is oriented substantially transversely of the longitudinal extension of the current conductors 10 as well as transversely of the intended direction of deflection of these current conductors.

When there is a small distance between the

pole shoes

17 and 18 for example for making narrow ribbons by using a limited number of conductors 10 arranged side by side, the magnet can comprise a permanent magnet. When there are greater distances between the

pole shoes

17 and 18, then an electromagnet is suitably used, which may carry a superconductive exciter winding for achieving high intensities of the magnetic field.

The terminals 12, the switch pairs 13 and 14 as well as the busbars l5 and 16 can be arranged on a printed circuit board, and as

switches

13 and 14 there may be preferably used electronic semiconductor switch elements which may be provided in an array where they are spaced in any desired spacing on the printed circuit so that the individual current conductors 10 can be placed adjacent each other in any corresponding spaced relationship apart from each other.

In order to avoid twisting or entanglement between the warp threads or between the current conductors l0 by reason of their closely adjacent arrangement, it can be advantageous in accordance with the embodiment shown in FIG. 4 to connect each of the current conductors 10 by way of a sail-like or wafer-like plate 19 with the associated ear 7 so that the individual wafers or plates 19 located parallel to each other ensure a guide for the current conductors l0 and also for the warp threads 7 during the upward and downward movement of the current conductors 10. According to an embodiment which is not shown here, for this purpose each plate or wafter 19 can be also lengthened underneath the ear 7 so that the ear 7 is enclosed by an associated plate 19 or constitutes part of this plate.

FIG. 3 shows an embodiment wherein the current conductors selectively connectable to voltage constitute a coil 20 the coil side 21 of which formed of a plurality of current conductors extending parallel to each other upon connection via switch means 22 to a voltage source 23 cooperates with the magnetic field existing between the magnet poles l7 and 18 in the sense of a lifting of the coil 20 concerned.

The coils 20 are mounted by an etching technique or by a pressing technique onto coil carriers 24 which consist of thin wafers of synthetic material or of thin plates of a magrietizable material.

As shown in FIG. 3a, the coils 20 disposed on the coil carrier 24 can be covered with an insulating layer 25 which has excellent sliding characteristics and which consists for example of tetrafluoroethylene. When the coil carriers 24 are made of magnetizable material, for example of a ferrite, then the additional advantage is achieved that nearly the whole air interspace between the

pole shoes

17 and 18 is filled up with a material of higher permeability so that the magnetic resistance of the closing circuit can be decreased and the effective field intensity for each coil 20 can be enhanced.

In the structure according to FIG. 3b, the coil carrier 24 consists also of a ferromagnetic plate, while a surrounding layer 25' consists of an epoxy resin which is mixed with ferrite and which can be applied by the dip-' ping method, spraying method or by vortex sintering, and into which the individual conductors of the coil 20 have been embedded in that after application of the conductive paths these paths are pressed into the layer 25' or covered with a second layer of epoxy resin mixed with ferrite. The advantage of this structure resides in that also the spaces filled with insulating material between the plates 24 have great permeability since the epoxy resin mixed with ferrite has a high electrical resistance but low magnetic resistance.

According to the modified embodiment in FIG. 3c, the ferromagnetic plate 24 is replaced by a fiberglass mat 24' which is embedded into ferrite epoxy resin.

As shown in the schematic view in FIG. 3, the individual coils 20 are connected via springy or resilient connecting lines with the switch means 22 and with the grounded busbar 11 respectively. For the sake of simplicity of the representation, a cassette-like or troughlike guide frame for the lateral support and guidance of the stack formed of the coils 20 is omitted. Should the sliding properties of the coil carrier 24 or of the coil cover 25 respectively be insufficient to achieve a reliable lifting of an individual coil 20 or of the associated coil carrier 24 respectively from the entire coil stack by using the produced electromagnetic driving forces, then on the guide frame there can be additionally provided also a means 40 for blowing-in of air into the coil stack whereby the frictional forces between the individual coils are practically eliminated. Similar means can be provided also for the embodiment according to FIG. 6 further described hereinbelow.

In corresponding manner like in the embodiment according to FIG. 1, the ears 7 are connected to the bottom portion to the coil carriers 24 by rods or heddles 9.

In the embodiment according to FIG. 1 as well as in that according to FIG. 3, however, the arrangement can be such that the warp threads run above the individual current conductors 10 and above the coils 20 respectively.

For the embodiment according to FIG. l, such a modification is shown in FIG. 2. The ears 7 in this embodiment are placed directly adjacent the top side of the current conductors 10 having the shape of bows which extend between the grounded busbar l 1 and the terminals 12 and which undergo a bending downwardly or upwardly according to the actuation of the

switches

13 and 14 in the sense of a connection with the

busbars

15 or 16.

According to a very important further development of the invention, the switch means for connection of the current conductors 10 and of the coils 20 respectively are designed so that they permit a short pulse-like current impingement of the conductors and coils respectively. The same applies to a device according to the invention in which the switch means are placed in their desired positions and held there during the working stroke which is then generated by a pulse-like current to the conductors and coils to which the switches are connected.

Such a short-time current impingement has the advantage that the permissible current intensities can be extraordinarily great without exceeding a maximum permissible thermal limit to achieve correspondingly great actuating forces, even though short-timed, bistable and tristable holding means can be provided in order to' maintain the individual warp thread in its actuated position for a duration sufficient for inserting the shuttle despite the shorttime switching-in of the electromagnetic drive such embodiments of the invention the short, great actuating force of the electromagnetic drive for the respective warp causes the holding means to change from one state into the other and then remain in this new state until the electromagnetic drive means is operated in the opposite sense. It is to be noted only in passing here that in such a case, in the embodiment according to FIG. 3, in place of the simple switch means 22 there should be provided the respective switch pairs 13 and 14 for connection with busbars of different polarity l5 and 16, respectively.

The bistable or tristable holding means can be a suitable mechanical, electromagnetic or magnetic means. Examples of magnetically effective bistable holding means are small magnet blocks or shoes secured along the upper edge of the coil carrier 24 and cooperating with a strip of ferromagnetic material extending above the coils in the transverse direction, or again a magnetic strip which cooperates with the coil carriers 24 made of magnetizable material so that an individual coil or its coil carrier 24 respectively is fixed-by the magnetic forces in the raised position until a current impingement in the opposite sense of the respective coil takesplace. I

An example of mechanically effective tristable holding means is given purely schematically in FIG. 5. Two

sector-shaped

plates

26 and 27 are urged apart from each other by a spring 28 and against respective associated (surfaces of engagement) 29' and 30 respectively. The coil carrier 24 is coupled via arms 31 to the

sectors

26 and 27 with respect to the vertical movements and can assume, in accordance with the cooperation of the

sectors

26 and 27 with the engagement surfaces 29 and 30, respectively, three stable positions which can be changed by short-timed current feeding of the coil 20 of the coil carrier 24. Of course, in place of the coil carrier 24 also a single current conductor 10 can be connected via arms 31 the top of FIG. 5.

The short-timed current impingement of the conductors or coils respectively while simultaneously using bistable or tristable holding means has the further advantage that the current impingement can be carried out in a rapid time sequence progressively, by a switch control device (41 FIG. 3). For example, from one conductor to another and from one coil to another respectively transversely of the longitudinal direction of the warp threads so that the shed is formed "likewise progressively in the transverse direction. In this manner, it is possible to carry out the actuation of the warp threads and the excitation of the electromagnetic drive means associated therewith respectively with a limited to the means shown in The embodiment according to FIG. 6 shows that the individual coils 20 when connected to voltage must not necessarily perform a translatory motion but can just as well perform a pivotal mo vemenLTo this end, the coil carrier 24 consisting of resilient material may be pivoted about a film fulcrum joint 32 over which also the supply lines for the coil 20 are passed in a flexible form. The stack of coils arranged adjacent each other is held by means of a clamping device 33 behind which are located the terminals 34 which are only schematically indicated in FIG. 6 and which lead to the switch means 13 and 14. According to a practical embodiment which however is not shown in detail in the drawings, a printed circuit board 42 is directly connected behind the clamping device 33. 4

While the apparatus according to the invention is not limited to particular weaving methods or particular dimensions of the woven fabric to be produced, the advantages of the invention are clearly shown in the example for making ribbons.

.What is claimed is:

1. Apparatus for forming a shed in the warp threads of a weaving loom comprising:

means for forming a magnetic field in a designated location; at least one electrical conductor in said location separate from said means for forming a magnetic field;

means for bodily connecting said electrical conductor to a corresponding warp thread; and,

means for selectively directing current to said electrical conductor to cause motion of said conductor and saidwarp thread bodily connected thereto.

2. Apparatus according to claim 1 wherein a plurality of electrical conductors is provided, each of said conductors being-bodily connected with a corresponding one of said warp threads and being selectively feedable with electric current.

3. Apparatus according to claim 1 wherein a plurality of electrical conductors is provide-d, each of said con ductors being bodily connected with a corresponding group of warp threads to be always actuated simultaneously and in one and the same direction.

4. Apparatus according to claim 1 wherein a plurality of groups of electrical conductors are provided each of said groups of conductors being bodily connected corresponding one of said warp threads and being selectively feedable with electric current.

5. Apparatus according to claim 1 wherein said at least one conductor extends parallel to the longitudinal direction of the corresponding warp thread.

6. Apparatus according to claim 4 wherein said electrical conductors of each group of conductors are arranged parallel to each other and are connected in series.

7. Apparatus according to calim 6 wherein said electrical conductors of each group of conductors are forming part of a flat coil.

8. Apparatus according to claim 7 wherein said conductors forming part of a flat coil are arranged on a thin plate shaped coil carrier.

9. Apparatusaccording to claim 8 wherein said conductors are applied to said coil carrier by being impressed therein.

. 10. Apparatus according to claim 8 wherein said conductors are applied to said coil carrier by an etching technique.

1 1. Apparatus according to claim 8 wherein said coil carrier consists at least partially of magnetizable material.

12. Apparatus according to claim 8 wherein means are provided for blowing a gas stream into the interspaces between the coil carriers.

13. Apparatus according to claim 8 wherein at least one of the surfaces of the coils and the coil carriers respectively is covered with a material of good sliding characteristics.

14. Apparatus according to claim 1 comprising holding means for selectively holding each electrical conductor in first or second positions and further comprising switch means for feeding current pulses to the conductors.

15. Apparatus according to claim 14 wherein said switch means are adapted for progressive control of the current feeding to each conductor in a time sequence in the direction of the breadth of the woven fabric.

16. Apparatus according to claim 14 wherein said holding means are mechanical means comprising a spring loaded snap actuating mechanism.

17. Apparatus according to claim 14 wherein said holding means are magnetic.

18. Apparatus according to claim 14 wherein said holding means are electromagnetic.

19. Apparatus according to claim 1 wherein each warp thread runs above the corresponding conductor in a groove or ear secured to the respective conductor.

20. Apparatus according to claim l'wherein each warp thread runs underneath the corresponding conductor in an ear secured to the respective conductor.

- 21 Apparatus according to claim 1 wherein flexible current supply lines connect said at least one conductor to printed circuit means extending across the breadth of the woven fabric.

22. Apparatus according to claim 7, wherein said flat coil is arranged on a coil carrier which is pivotable about a pivot point.

23. Apparatus according to claim 8, wherein at least one of the surfaces of the coils and the coil carriers, respectively is covered with a high permeability insulating material.

24. Apparatus according to claim 1 wherein aluglike guide plate is secured to each conductor said luglike guide plate extending parallel to the longitudinal direction of the respective conductor.

25. The apparatus of claim 13 wherein said material is comprised of tetrafluoroethylene.

26. The apparatus of claim 14 wherein said holding means is bistable.

27. The apparatus of claim 14 wherein said holding means is tristable.

'28. The apparatus ofclaim 23 wherein said high permeability insulating material is a ferrite epoxy resin.

Claims

1. Apparatus for forming a shed in the warp threads of a weaving loom comprising: means for forming a magnetic field in a designated location; at least one electrical conductor in said location separate from said means for forming a magnetic field; means for bodily connecting said electrical conductor to a corresponding warp thread; and, means for selectively directing current to said electrical conductor to cause motion of said conductor and said warp thread bodily connected thereto.

2. Apparatus according to claim 1 wherein a plurality of electrical conductors is provided, each of said conductors being bodily connected with a corresponding one of said warp threads and being selectively feedable with electric current.

3. Apparatus according to claim 1 wherein a plurality of electrical conductors is provided, each of said conductors being bodily connected with a corresponding group of warp thrEads to be always actuated simultaneously and in one and the same direction.

9. Apparatus according to claim 8 wherein said conductors are applied to said coil carrier by being impressed therein.

10. Apparatus according to claim 8 wherein said conductors are applied to said coil carrier by an etching technique.

11. Apparatus according to claim 8 wherein said coil carrier consists at least partially of magnetizable material.

17. Apparatus according to claim 14 wherein said holding means are magnetic.

20. Apparatus according to claim 1 wherein each warp thread runs underneath the corresponding conductor in an ear secured to the respective conductor. 21 Apparatus according to claim 1 wherein flexible current supply lines connect said at least one conductor to printed circuit means extending across the breadth of the woven fabric.

24. Apparatus according to claim 1 wherein a lug-like guide plate is secured to each conductor said lug- like guide plate extending parallel to the longitudinal direction of the respective conductor.

26. The apparatus of claim 14 wherein said holding means is bistable.

27. The apparatus of claim 14 wherein said holding means is tristable.

28. The apparatus of claim 23 wherein said high permeability insulating material is a ferrite epoxy resin.