GB2311301A - Electronic device for controlling sensing pins of a mechanical jacquard system - Google Patents

Abstract

A jacquard device comprises a reciprocating part 4 in which a body 8 is formed with parallel cylinders each containing a piston 10 whose head makes selective engagement with an associated sensing pin of the device on reciprocation of the part 4, depending on whether the piston head is flush with the face of part 4 or is held in a retracted position. Retraction of selected pistons is effected by latching engagement with a hook 44 on a blade whose position is controlled by an electromagnet under electronically programmed control. The piston is normally extended by a spring 24.

Description

Description The present invention relates to an electronic device for controlling sensing pins of a mechanical jacquard system, avoiding the need to use punched cards.

In the field of the textile industry, mechanical jacquard systems are commonly used to produce complex designs, in particular for knitwear and the manufacture of lace. In each row it is necessary to alter the position of hooks to position the warp threads such that the desired effect is produced for obtaining the desired design.

Punched cards are generally used to control the movement of the hooks in known devices. These punched cards are mounted on a support performing a reciprocating motion.

Sensing pins are located opposite this support on the side of the punched card. The support is placed in the extension of these pins and travels parallel to them.

During its reciprocating motion, the punched card comes to the level of the end of the pins and continues its travel beyond it. The pins located in the region of a hole in the punched card are not entrained whereas those located in the region of a solid portion of the punched card are entrained. These pins entrain a hook associated with a warp thread either directly or by means of one or more mechanical gears.

A new punched card is placed on the support in each row and the support performs reciprocating motion. It is known to connect the punched cards to one another by means of at least one thread and to pass them over a cylindrical drum of polygonal, for example hexagonal, cross section. The support formed by the drum is thus given double motion, that it rotation round the axis of the drum and translation perpendicularly to this axis.

This technique has a certain number of drawbacks. Firstly, the cards are generally punched manually. It is therefore necessary to produce, for a machine, as many cards as there are shuttle passages to produce a pattern and it is necessary to produce as many sets of cards required for a pattern as machines which are to produce this pattern.

Production of these cards is therefore very time-consuming.

Consequently, the size of the patterns is often reduced and the same pattern is repeated several times.

The cards as well as the threads connecting them are subjected to numerous mechanical stresses and wear. Their service life is limited. Sets of cards therefore have to be replaced regularly.

A set comprising the cards required to produce a design on a woven or knitted part is more or less bulky, depending on the complexity of the design and its size. A large amount of space is required in weaving mills employing this technology for storing the various sets of cards forming a library of designs for each jacquard loom in the mill.

Finally, when a set of cards is placed on a jacquard system, adjustments are required to guarantee that the desired design is produced well.

There are already jacquard systems in which the perforated cards have been replaced by an electronic control system.

These new jacquard systems have a novel design and employ a mechanism quite different from that of mechanical jacquard systems intended to use punched cards.

The aim of the invention is therefore to provide a device for controlling sensing pins of a mechanical jacquard system not having the drawbacks of devices with punched cards, increasing flexibility while allowing designs of the desired size and complexity to be made without demanding a large amount of time for the programming of the jacquard system or for placing a new design on a jacquard loom while allowing adaptation to jacquard looms employing punched cards.

To this end, the device which it proposes comprises: - a die comprising parallel cylindrical recesses opening into the same face of the die and intended to travel with reciprocating motion parallel to the axis of the cylindrical recesses, - pistons, each of which corresponds to a cylindrical recess in the die, comprises a piston head and a piston rod and is intended to travel between a position where the piston head is flush with the face of the die in which the cylindrical recesses open and a position where the piston is retracted to the interior of the die, these pistons each being intended to come into contact with a sensing pin, - means allowing each piston to travel independently of the other pistons in its recess, and - means for controlling the travel of the pistons comprising an electronically controlled memory.

In this novel device according to the invention, the die and its pistons replace the prior art punched cards and their support. When retracted, the pistons correspond to a hole in a punched card and when they are flush with the surface of the die, they correspond to a solid zone of the card.

Owing to the reciprocating motion of the die, this novel device can easily be adapted to a jacquard loom comprising a device for controlling the sensing pins operating with punched cards.

There are numerous solutions for displacing the pistons.

The piston rod or a lever connected to the piston rod can be drawn, for example, by an electromagnet.

According to a preferred embodiment, the reciprocating motion of the die is utilised to displace the pistons. In this embodiment, the means allowing the travel of the pistons comprise a plate which is stationary relative to the hook-carrying die, each hook corresponding to a piston and being mechanically connected to the rod'thereof and a hook selecting device is mounted stationarily opposite the hook-carrying plate and which travels with reciprocating motion with the die such that, when a hook is selected, the corresponding piston retracts into the die when the die moves away from the hook selecting device.

The device for selecting hooks is advantageously of the type described and claimed in French patent application FR2 736 659. In this case, the hook selecting device comprises parts equipped with a lug, each of these parts corresponding to a hook and the position of the lug relative to the hook being controlled by an electromagnetic device having at least one coil such that, when the plate moves away from the selecting device, the lug, depending on its position, engages or does not engage with the hook.

Each part equipped with a lug is a rigid blade comprising at least one part produced from magnetic material mounted pivotally round a pin. The selecting device comprises means for creating a permanent magnetic field in the region of the part produced from magnetic material of the blade, and the coil allows actuation of the part of the blade produced from magnetic material such that, depending upon the polarities of the coil and of the permanent magnetic field, the blade pivots round its pin either into a first position allowing it to be engaged with the corresponding hook when the plate moves away from the selecting device or into a second position not allowing such entrainment.

A selecting device of this type allows very rapid and reliable selection of the hooks. Furthermore, the power consumption of this device is low.

In a first variation, each piston rod is connected to the corresponding hook by a thread and a spring mounted round the piston rod returns the piston into the position where the piston head is flush with the face of the die in which the cylindrical recesses open. This variation is a priori the most simple but it necessitates different cord lengths for each piston if the distance between a piston and the corresponding hook is not constant. Now for reasons of bulk and accessibility, it is preferable to have hooks which are more spaced from one another than the pistons.

The length of each cord therefore has to be adjusted.

A second advantageous variation is therefore proposed in which each piston and the corresponding piston rod form a single part of synthetic material in which the piston rod is relatively flexible and is guided in a sheath resting on the one hand on the die on the side where the piston rod issues from it and, on the other hand, on a plate parallel to the hook-carrying plate and placed between the die and the hook-carrying plate.

In this second embodiment, it is possible to have similar pistons, hooks and sheaths for all the cylinders of the die. Advantageously, the die and the sheaths for the piston rods form a single part of synthetic material, the small thickness of the cylindrical walls constituting the sheaths allowing flexibility to be obtained. This facilitates assembly of the system and reduces the cost price.

Still with the aim of facilitating assembly of the control device, the die receiving the pistons and the plate carrying the hooks are fixed on a plate forming the base of a box closed by a cover, the face of the die in which the cylindrical recesses open forming a face of the box and the hooks placed on their plate issuing from the box on the face opposed to the aforementioned face.

To enable the device for controlling sensing pins to be adapted easily to a given jacquard loom by adapting, for example, the number of cylinders to the number of threads to be selected, the die is advantageously formed from identical independent modules connected to óne another by mating shapes.

In any case, the invention will be understood by means of the following description given with reference to the accompanying schematic drawings illustrating, by way of non-limiting examples, two embodiments of an electronic device for controlling sensing pins of a mechanical jacquard system.

Figure 1 is a perspective view of a device according to the invention.

Figure 2 is a general view showing the device according to the invention placed in a mechanical jacquard system on a reduced scale.

Figure 3 is a schematic sectional front view on an enlarged scale.

Figure 4 is a view similar to that in figure 2 of a different embodiment.

Figure 5 is a sectional view along line V-V in figure 4.

Figure 6 is a perspective view of a constituent module of a die of the device shown in figures 4 and 5.

Figure 1 shows an electronic device for controlling a mechanical jacquard system. This device allows actuation of sensing pins not shown in this figure. These sensing pins actuate, generally via a mechanical unit, the warp threads of a weaving loom. The corresponding warp threads can be selected according to the position of these pins.

To actuate these sensing pins it is known in the prior art to use punched cards placed on a hollow support performing reciprocating motion. The card moves towards and away from the ends of the sensing pins. The pins located opposite a hole in the punched card do not move and the others are entrained in the travel of the support, indirectly entraining the corresponding thread with them.

The devices shown in the drawings allow a prior art device as described briefly hereinbefore to be replaced. These devices comprise (figure 1) a stationary upper part 2 and a lower part 4 which is movable relative to the upper part 2.

Figure 1 shows two guide rods 6 fixed on the stationary upper part 2 and on which the lower part 4 moves in translation.

The means allowing the relative travel of the lower part 4 with respect to the upper part 2 are known to a skilled person and are not shown in the drawings. There may be, for example, a pneumatic jack working between two stops or an electric motor with a cam mounted on its output shaft.

Other solutions can obviously be considered and exist on mechanical jacquard systems known to a skilled person.

Figure 2 shows the device from figure 1 in a mechanical jacquard system intended to be controlled by punched cards.

The moving part 4 replaces a control device operating with punched cards. It is provided with a translation movement, for example from bottom to top or from top to bottom, as indicated by the double arrow 100.

Sensing pins 102 oppose the moving part 4. In its motion, the moving part 4 comes toward the pins 102 and displaces some of them.

The displaced sensing pins 102 raise a horizontal blade 104. One end of this blade 104 is connected to a thread 106 and the other end has a shoulder 108.

In the rest position shown in figure 2, the moving part 4 is not in contact with the pins 102. The blades 104 are in the low position and each rest on a step 110 of an openwork part capable of travelling substantially parallel to the blades 104, as indicated by the double arrow 112.

In its motion, the open-work part entrains, via the steps 110 and the shoulders 108, the blades 104 which are not in the raised position. The blades 104 therefore act on the corresponding thread 106. This thread is either directly connected to a warp thread or controls a warp thread via a mechanism.

Therefore, when the moving part 4 is raised, it entrains certain sensing pins 102 which, in turn, act on a blade 104. The open-work part entrains in its movement the blades 104 which are not raised and which therefore control the threads 106.

The manner in which the moving part 4 allows a punched card and its support to be replaced and the means which it employs for this purpose are described hereinafter.

The lower part 4 has a substantially cuboid shape. It comprises a die 8, pistons 10 sliding in cylinders 12 made in the die and hooks 14 mounted on a plate 16.

The die 8 is arranged in the lower part 4 on the side remote from the upper part 2. The cylinders 12 open in the lower face of the die 8. Their axis is parallel to the direction of travel of the lower part 4 relative to the upper part 2. The end of a sensing pin controlling the travel of a thread corresponds to each cylinder 12, as described for example hereinbefore.

In each cylinder 12 there is a piston 10. The pistons 10 each comprise a piston head 18 and a piston'rod 20. The piston head 18 is located on the side of the lower face of the die and the piston rod 20 is orientated toward the interior of the lower part 4. The piston 10 travels between a position where its head is flush with the lower face of the die 18 corresponding to the lower face of the lower part 4 and a retracted position within the die 8.

The unit formed by the die 8 and the pistons 10 becomes equivalent to a prior art punched card. When a piston is flush with the lower face of the die, the lower part 4 entrains the end of the corresponding sensing pin with it during its travel but it does not act on the pins corresponding to a cylinder 12 of which the piston 10 is retracted.

The upper face of the lower part 4, that is the face turned toward the upper part 2, is formed by the plate 16 carrying the hooks 14. These hooks are slidably mounted on the plate 16 in a direction parallel to the travel of the pistons 10. A stop 22 attached to each hook 14 determines the rest position thereof. This stop 22 rests on the upper face of the plate 16.

Each hook 14 is connected to the piston rod 20 of a piston 10. Therefore, when a hook 14 is drawn upwardly, the corresponding piston retracts within the die 8. A helical spring 24 is placed in each cylinder 12 round the corresponding piston rod 20 to return the piston 10 into its position where its head 18 is flush with the internal face of the die 8. Two embodiments are described below for the connection between the pistons 10 and the hooks 14.

In the first embodiment (figure 3), the piston rod 20 is connected to the hook by a cord 26. The spring 24 returns the system to its rest position, in other words the head of the piston 18 is flush with the lower face of the die 8 and the corresponding stop 22 rests on the plate 16. The length of each cord 26 is determined so that just the stop 22 rests on the plate 16 when the corresponding piston head 18 is flush with the lower surface of the die 8. When the hook 14 is drawn upwardly relative to the lower part 4, the piston head 18 retracts into the die 8 until the external action on the hook 14 ceases.

The second embodiment (figure 4) is the preferred embodiment. In fact, the drawback of the above-described first embodiment is that the length of the cords 26 has to be adjusted for each piston/hook assembly has to be adjusted. Figure 3 shows that the length of the cord 26 varies between two adjacent cylinders 12. The second embodiment overcomes this drawback.

In this preferred embodiment, the piston rod 20 is produced from a material which allows it to be flexible.

Advantageously the piston head 18 and its rod 20 are produced by moulding and are made of synthetic material.

All the pistons 10, that is the piston head/piston rod units, are identical. The flexible piston rod 18 catches on the end of the corresponding hook 14 located within the lower part 4. It is guided to its exit from the die 8 in a sheath 28 which is also flexible. Each sheath 28 has the same length and is fixed at its ends on the one hand to the die 8 and on the other hand to a second plate 30 parallel to the first plate 16 and located between the die 8 and the first plate 16.

The sheaths 28 are advantageously connected to the die 8 in this embodiment. The die 8 can consist of modules 32 such as the one shown in figure 6. This module 32 is produced from synthetic material, by moulding. It has four cylindrical recesses forming four cylinders 12 opening into a face of the module 32. A sheath 28 issues from each cylinder 12 on the opposing face. The sheaths 28 and the die 8 are therefore produced from the same material. The flexibility of the sheaths is obtained in that their wall is sufficiently fine to acquire a certain degree of flexibility. The various modules 32 fit in one another to form the die 8.

Figure 5 shows how the various constituent elements of the lower part 4 of the device are assembled. This lower part 4 comprises a base 34 consisting of a profile having a Ushaped cross section (figure 1). Various elements described hereinbefore such as the first plate 16 forming the upper wall of the lower part 4, the second plate 30 and the die 8, possibly consisting of several modules 32 forming the lower wall of the lower part 4 are fixed on this base 34. Access for installation of these various elements is easy. It is also easy to introduce the pistons into their corresponding cylinders and to position the sheaths. Once everything has been installed, a cover 36 is positioned and closes the lower part 4 which has the form of a box. Screws 38 hold the unit together.

The lower part 4 is set into vertical reciprocating motion.

It moves toward and away from the upper part 2. The stationary part 2 is equipped with hook selecting devices 40 comprising blades 42 each equipped at their end with a lug 44 facing a hook 14. When the lower part 4 is located in the vicinity of the upper part 2, the hooked end of the hooks 14 is located above the lugs 44. The blades 42 therefore position themselves such that, when the lower part 4 moves away from the upper part 2, the hooked part of the hooks 14 remains in engagement with the corresponding lug 44. Thus, during the travel of the lower part 4, the hook 14 is held in position, issuing from the lower part 4 and drawing the corresponding piston 10 toward the interior of the lower part 4. During each reciprocating motion of the lower part, other hooks can be selected and the configuration of the lower face of the die 8 is altered in the same way as when a punched card on a support is changed.

In a preferred embodiment, each hook selecting device 40 is a device as described hereinafter.

The blades 42 are pivotally mounted in a box 46. Each blade 42 is equipped with a transverse pin 48 mounted on bearings 50 provided on a wall of the box 46.

The blades 42 comprise a recess 52 on the side remote from the lug 44. A permanent magnet 54 is placed between two polar parts 56 within this recess 52. One end of each polar part 56 projects from this recess.

Opposite the blade 42 on the side with the magnet 54 and the polar parts 56 there is a reinforcement 60 and a coil 58. This coil 58 can be traversed by a direct electric current. A printed circuit board 64 controls the passage of the current in the coil 58.

The reinforcement 60 has the form of an E of which the teeth are orientated toward the blade 42. Between each two branches of the E there is one end of a polar part 56. The central branch of the E carries the coil 58.

A gap 62 made in an amagnetic material is placed on each face of a branch of the E facing a polar part 56.

The mode of operation of this hook selecting device is described hereinafter.

The polarity of the median branch of the reinforcement depends on the direction of the current in the coil 58.

The polarities of the two lateral branches of the reinforcement oppose the polarity of the median branch.

The polarities of the two polar parts do not vary and are opposed.

In equilibrium, whether or not current is passing in the coil 58, each polar part 56 abuts against the end of a branch of the reinforcement 60. If current is passing in the coil 58 in the direction opposed to the last passage of current, the polarity of the central branch of the reinforcement varies as does that of the lateral branches.

The polar part 56 abutting against the median branch of the reinforcement is therefore pushed back by the median branch of the reinforcement but also attracted by a lateral branch. The same applies to the other polar part which is pushed back by the lateral branch against which it rested and is attracted by the central branch.

The gaps 62 produced from amagnetic material, allow the force of attraction between the polar parts 56 and the branches of the reinforcement 60 to be adjusted.

The blade 42 of the hook selecting device can assume two stable positions: one corresponds to the selection of the corresponding hook 14 and the other to the non-selection thereof.

In the absence of current in the coil 58, the blade 42 remains in the position in which it is located both in the selection and non-selection position. Providing a new electromagnetic field generated by a current in the opposite direction in the coil 58 does not alter the polarity of the branches of the reinforcement 60, the blade 42 remains in a stable position.

In this device, a few milliseconds are sufficient to cause the blade 42 to rock from one position to another. The hooks 14 can therefore be selected rapidly. Power consumption is minimised as a result.

As can be seen in figure 5, the lug 44 merely has to pass beneath the hooked part of the hook 14 to select or not to select this hook. The travel of the lower part 4 relative to the upper part 2 can therefore be reduced to the necessary minimum.

An electronically controlled memory stores all the configurations necessary to produce a pattern on a jacquard loom equipped with this device. This memory can be located, for example, on a smart card 66. A reader 68 allows the content of this memory to be read and supplies the information stored to each printed circuit board 64 of the hook selecting devices 40.

The smart card 66 can contain the information can contain the information necessary to produce a pattern, even if the pattern is very complex. The size of this card is almost negligible relative to the size of the punched cards which it replaces. The storage problem is therefore solved.

The data required to produce a pattern can be stored on a computer. Once the data have been acquired, it is possible to create as many smart cards 66 as desired in a short period of time. This rapid duplication is impossible with prior art punched cards.

Finally, as the smart card is not mechanically stressed, it is not worn. The problem of wear is therefore solved.

An advantage of the above-described device is that it can be adapted to a jacquard loom equipped with a punched card control system. The reciprocating motion performed by a support intended to receive punched cards effectively takes place in this device for controlling sensing pins. The device according to the invention merely has to be arranged such that the lower face of the die describes the same trajectory as a punched card in order to allow electronic control of the sensing pins with the same mechanism.

It will be appreciated that the invention is not limited to the embodiments described by way of non-limiting examples.

On the contrary, it covers all variations.

For example, the hook selecting device can be of a type different from that described hereinbefore. The hooks of the lower moving part could be replaced by a magnetic metal part or by a permanent magnet. An electromagnet would replace the blade and its lug. When the lower part of the device comes toward the upper part, the current passing in the electromagnets would be adapted to obtain the desired configuration of the pistons during the following travel of the lower part.

The die and the pistons can be produced from a material other than synthetic material, for example from metal.

The memory in which the data required to produce a pattern are stored can be the memory of a personal computer. Such a computer could be connected to each jacquard loom. The data would thus be stored on a disk of a common type.

Claims (8)

Claims

1. Device for controlling sensing pins of a mechanical jacquard system, characterised in that it comprises: - a die (8) comprising parallel cylindrical recesses (12) opening into the same face of the die and intended to travel with reciprocating motion parallel to the axis of the cylindrical recesses, - pistons (10), each of which corresponds to a cylindrical recess (12) in the die, comprises a piston head (18) and a piston rod (20) and is intended to travel between a position where the piston head (18) is flush with the face of the die in which the cylindrical recesses open and a position where the piston (10) is retracted to the interior of the die (8), - means allowing each piston (10) to travel independently of the other pistons in its recess (12), and - means for controlling the travel of the pistons comprising an electronically controlled memory.

2. Device according to claim 1, characterised in that the means allowing the travel of the pistons (10) comprise a plate (16) which is stationary relative to the die (8) carrying hooks (14), each hook corresponding to a piston (10) and being mechanically connected to the rod (20) thereof and in that a hook selecting device (40) is mounted stationarily opposite the plate (16) carrying the hooks (14) and which travels with reciprocating motion with the die (8) such that, when a hook (14) is selected, the corresponding piston (10) retracts into the die (8) when the die (8) moves away from the hook selecting device (40).

3. Device according to claim 2, characterised in that the hook selecting device (40) comprises parts (42) equipped with a lug (44), each of these parts (42) corresponding to a hook (14) and the position of the lug (44) relative to the hook (14) being controlled by an electromagnetic device having at least one coil (58) such that, when the plate (16) moves away from the selecting device (40), the lug (44), depending on its position, engages or does not engage with the hook (14), in that each part (42) equipped with a lug (44) is a rigid blade comprising at least one part (56) produced from magnetic material mounted pivotally round a pin (48), in that the selecting device (40) comprises means (54) for creating a permanent magnetic field in the region of the part (56) produced from magnetic material of the blade (42), and in that the coil (58) allows actuation of the part (56) of the blade produced from magnetic material such that, depending upon the polarities of the coil (58) and of the permanent magnetic field, the blade (42) pivots round its pin (48) either into a first position allowing it to be engaged with the corresponding hook (14) when the plate (16) moves away from the selecting device (40) or into a second position not allowing such entrainment.

4. Device according to one of claims 2 or 3, characterised in that each piston rod (20) is connected to the corresponding hook (14) by a thread (26) and in that a spring (24) mounted round the piston rod (20) returns the piston into the position where the piston head (18) is flush with the face of the die (8) in which the cylindrical recesses (12) open.

5. Device according to one of claims 2 or 3, characterised in that each piston (10) and the corresponding piston rod (20) form a single part of synthetic material and in that the piston rod (20) is relatively flexible and is guided in a sheath (28) resting on the one hand on the die (8) on the side where the piston rod issues from it and, on the other hand, on a plate (30) parallel to the plate (16) carrying the hooks (14) and placed between the die (8) and the plate (16) carrying the hooks (14).

6. Device according to claim 5, characterised in that the die (8) and the sheaths (28) for the piston rods form a single part (32) of synthetic material, the'small thickness of the cylindrical walls constituting the sheaths allowing flexibility to be obtained.

7. Device according to one of claims 2 to 6, characterised in that the die (8) receiving the pistons (10) and the plate (16) carrying the hooks (14) are fixed on a plate (34) forming the base of a box closed by a cover (36), the face of the die in which the cylindrical recesses (12) open forming a face of the box and the hooks (14) placed on their plate (16) issuing from the box on the face opposed to the aforementioned face.

8. Device according to one of claims 1 to 7, characterised in that the die (8) consists of identical independent modules (32) connected to one another by mating shapes.