EP0079843A1 - Electromagnetic device for operating dobbies - Google Patents

Abstract

The block (19) which contains the electromagnets is carried by an oscillating frame (20-21) on which is mounted an equal number of selectors (23) associated with a spring which tends to separate them from their poles of attraction. Each selector acts selectively on the actuating hooks (11, 12) of the rotary dobby, a fixed stop (26a) ensuring its return to the glued position when returning to the separated position. The patent also describes the application of the device to the control of a dobby with oscillating scales.

Description

The present invention relates to weaving dobbies, it being understood, however, that this term generically encompasses the various types of mechanics associated with weaving machines with a view to forming a crowd for the passage of weft threads.

It is known that in the conventional form a dobby comprises a single control device which, according to a variable program corresponding to the particular weave desired for the fabric being produced on the weaving machine, actuates vertically a series of frames of smooth ensuring the operation of the warp threads. As a result of the tension of the wires which pass through the eyelets of the heddles of the same frame, the vertical displacement of the latter implies a significant effort, so that between the control device and the cables or operating rods linked to each of the different frames of the dobby, an independent amplifier system must be interposed, the assembly formed by each frame and by its amplifier system constituting what is called a "blade" of the dobby.

The control device includes in the first place a reading device for reading the weaving program, this program possibly depending on the case being in the form of a continuous strip of perforated paper, of an articulated series of perforated cartons, of 'a chain or an ankle cylinder, etc ... The information recorded by the reading device must be transformed into mechanical movements by a relatively complex actuation mechanism, incorporating a series of mobile rods maneuvered by motor knives with reciprocating movement or by rotating cams. At each of the dobby blades, this actuation mechanism comprises at least one output member which acts selectively on one or the other of a pair of tilting hooks ensuring actuation of the corresponding amplifier system, this can depending on the case, be of the rotary type or of the oscillating balance type.

Consideration has been given to simplifying the construction of the control device by replacing the actuation mechanism interposed between the reading apparatus and the pairs of tilting actuation hooks, by two series of electromagnets, each series comprising a number d electromagnets equal to that of the dobby blades. It is in fact understood that each of these electromagnets is capable of being selectively supplied by the reading device in order to act, by means of a corresponding movable member, on that of the two tilting hooks of the envisaged blade with which it is associated.

Attempts to do so, however, have not been entirely satisfactory in practice. Ordinarily the electromagnets of each series are mounted side by side in an insulating block permanently fixed to the frame of the dobby, and if we take into account the corresponding row of movable members associated with each block, we results in a very bulky device whose accommodation in the free space, necessarily cramped, of a dobby is quite delicate.

It is to this drawback that the present invention intends mainly to remedy, by making it possible to produce an electromagnetic control device for dobby which is of simple construction in a small footprint and of perfectly satisfactory operating reliability, whatever the speed of work of the weaving machine with which the dobby is associated.

The invention consists essentially in providing a single set of electromagnets mounted on a frame driven by an oscillating movement linked to that of the dobby in order to approach and move cyclically said electromagnets from the different pairs of dobby control hooks, and to interpose between each of the electromagnets and the corresponding pair a single selector carried to tilt by the aforementioned chassis. Each selector is associated with elastic means which tend to separate it from the poles of attraction of its electromagnet, but when it is in the separated position this selector cooperates with a stop so as to be brought back into position glued against said poles when during its oscillating movement the chassis moves away from the pairs of hooks.

We understand under these conditions that depending on whether the electromagnet envisaged is powered by the reading device or not depending on the armor program, the selector will remain stuck or on the contrary be moved away by its elastic return means, if although when the chassis approaches again the pairs of hooks, this selector will come to bear against one or against the other of the hooks of the pair concerned. It should be observed that in such a process the electromagnets never operate the positive displacement of the selectors; their role is limited to retaining, against the elastic return means, the selector which has applied against their poles, or on the contrary to releasing it, so that the effort which they provide is very reduced .

It is also understood that the uniqueness of the block of electromagnets considerably simplifies the control by the reading device at the same time as it significantly reduces the overall size. The tilting selectors interposed between the electromagnets and the pairs of hooks are capable of ensuring a force amplification role which simplifies the construction and which makes it possible to have recourse to lower supply currents.

• Fig. 1 est une coupe transversale schématique illustrant l'agencement général d'un dispositif électromagnétique établi suivant l'invention pour la commande d'une ratière du type rotatif.
• Fig. 2 montre les pièces formant l'un des systèmes amplificateurs de la ratière rotative suivant fig. 1.
• Fig. 3 est une coupe longitudinale à plus grande échelle représentant à l'état monté les pièces de l'ensemble suivant de fig. 2.
• Fig. 4 à 7 sont des coupes partielle à plus grande échelle, illustrant le fonctionnement du dispositif de commande suivant fig. 1.
• Fig. 8 est le diagramme des mouvements des différents éléments mobiles de la ratière suivant fig. 1 à 7.
• Fig. 9 est une coupe montrant l'agencement d'un dispositif électromagnétique suivant l'invention pour la commande d'une ratière du type à balances.
• Fig. 10 à 13 montrent à plus grande échelle le fonctionnement de ce dispositif.
• Fig. 14 est le diagramme des mouvements.

The appended drawing, given by way of example, will allow a better understanding of the invention, the characteristics which it presents and the advantages which it is capable of providing:

• Fig. 1 is a schematic cross section illustrating the general arrangement of an electromagnetic device established according to the invention for controlling a dobby of the rotary type.
• Fig. 2 shows the parts forming one of the amplifier systems of the rotary dobby according to FIG. 1.
• Fig. 3 is a longitudinal section on a larger scale representing in the assembled state the parts of the following assembly of FIG. 2.
• Fig. 4 to 7 are partial sections on a larger scale, illustrating the operation of the control device according to FIG. 1.
• Fig. 8 is the diagram of the movements of the various mobile elements of the dobby according to FIG. 1 to 7.
• Fig. 9 is a section showing the arrangement of an electromagnetic device according to the invention for controlling a dobby of the type with scales.
• Fig. 10 to 13 show on a larger scale the operation of this device.
• Fig. 14 is the movement diagram.

The rotary dobby illustrated in fig. 1 to 3 is of the type which was the subject of French patent application No. 81.20502 filed October 29, 1981 in the name of the Applicant. The main shaft 1, connected to the input shaft of the dobby through a modulating mechanism so as to be driven by an intermittent rotational movement with stops every 180 °, supports the various amplifying systems of the dobby. As more particularly shown in fig. 2 and 3, each system comprises an eccentric 2 mounted idly on the shaft 1 and provided with a lateral plate 3 on which a ratchet is articulated laterally 4. The eccentric 2 is engaged in the opening of a connecting rod 5 who is harnessed, by means of an arm 6 (fig. 1) pivoting on a fixed axis 7, with the usual draw lever (shown diagrammatically at 8) connected to the heald frame which corresponds to the envisaged blade of the dobby.

Each of the amplifier systems also comprises a circular disc or driver 9, the central opening of which is crenellated to cooperate with the longitudinal grooves of the main shaft 1. At two diametrically opposite points on its periphery, this disc 9 is cut out of two notches 9a (fig. 2) which are intended to cooperate with a finger 4a formed at one end of the coupling pawl 4. The opposite end of the latter is arranged at a notch 3a formed in the periphery of the plate 3 secured to the eccentric 2. It will be observed that a spring 10 (fig. 1), interposed between a radial tab of the plate 3 and the pawl 4, tends to elastically hold the finger 4a against the periphery of the disc 9 .

As described in the aforementioned patent application, the actuation of each blade of the dobby is operated using two tilting hooks 11 and 12 having two arms oriented at right angles on either side of a fixed axis pivot 13, respectively 14 carried by the walls of the housing A of the dobby. One of the arms of each hook is profiled to present a spout lla, 12a suitable for engaging, as will be seen below, in the notch 3a of the plate 3 to push back the pawl 4 during each stop of the shaft 1 and thus immobilize the eccentric 2. The other arm, intended to receive the action of the control device according to the invention generally referenced 15, is biased by a spring 16 which thus tends to engage the spout lla, respectively 12a, in the notch 3a. The control device 15 comprises a reading device shown diagrammatically at 17, arranged to take information on an armor program, assumed to be formed by a chain of perforated cartons 17a. This information is transformed by the device 17 into electrical pulses which are sent by a cable 18 to a single control unit with electromagnets 19, advantageous ment of the type described in French patent application No. 80 10548 filed May 6, 1980 in the name of the Applicant. This block 19 contains a series of electromagnets in number equal to that of the blades of the envisaged dobby, each electromagnet 19a receiving from the device 17 the pulses corresponding to its blade.

The block 19 is carried by a frame formed by two arms 20 joined to one another by a profile 21 made integral with said block. The two arms 20 are wedged on a shaft 22 which is driven from the input shaft of the dobby through a modulator, so as to be driven by an oscillating movement.

In addition to the reading device 17 and the block of electromagnets 19 carried by the oscillating frame 20-21, the control device 15 also comprises a series of selectors 23 in number equal to that of the blades of the dobby, all of these selectors being brought to free tilting by a pin 24 whose ends are fixed to the arms 20 of the aforementioned chassis. Each selector 23 is provided with a metal plate 23 'pivotally attached and intended to cooperate with the poles of the electromagnet 19a which corresponds to it in the block 19, it being observed that a spring 25 (fig. 4) tends to move said selector away from the aforementioned poles. The lower part of each of the selectors 23 is profiled to determine a kind of nose 23a suitable for acting, as will be seen below, on the corresponding end or tail of the tilting hooks 11 or 12, while it comprises laterally a heel 23b which cooperates with a fixed stop 26a provided on one of two crosspieces 26 fixed in the casing A below the lowest point of the oscillating travel of the block 19.

The operation of the above-described control device appears from the examination of FIGS. 4 to 7, but to expose it logically we will first refer to fig. 1 where it has been assumed that the oscillating chassis 20-21 is in the high position of its travel; the electromagnet 19a of the block 19 which corresponds to the selector 23 envisaged is excited, so that the latter is applied against the poles of said electromagnet, against the action of its spring 25. The two springs 16 hold the tilting hooks 11 and 12 bearing against the lower part of the fixed stops 26.

It is also advisable to observe beforehand the diagram of the movements of fig. 8 in which line 1 corresponds to the jerky movement of the shaft 1 while in line II appears the oscillating movement of the shaft 22 and the chassis 20-21. It can be seen that the shaft 1 begins to rotate 180 ° when the chassis 20-21 reaches the lower end of travel. Of course the vertical movements of the selector 23 are linked to those of the chassis 20-21, its angular movement appearing at line III of the diagram; we can see that this selector 23 normally sticks against the electromagnet 19a when the aforementioned frame arrives in the high position. Finally, it will be noted that the electrical control of the electromagnets of block 19 occurs (line IV) at the moment when the frame 20-21 begins its upward stroke.

Starting therefore from the position shown in fig. 1 (point O in fig. 8), it is checked that during the rotation of the shaft 1 the oscillating frame is lowered in the direction of the hooks 11 and 12 (fig. 4) and that the electromagnet 19a , kept excited, retains the selector 23 in the glued position so that the nose 23a thereof comes to bear against the tail of the hook 11 which is thus pushed back. The tilting of this hook 11 against its spring 16 causes the nozzle 11a to be extracted from the notch 3a of the plate 3; the pawl 4 is released and therefore tilts under the effect of its spring 10 to engage its spout 4a in the notch 9a of the disc 9 which was placed immediately opposite. The eccentric 2 is then made angularly integral with the shaft 1 through the plate 3, the pawl 4 and the disc 9, so that as soon as the shaft 1 starts a new rotation of 180 ⁰ , the connecting rod 5 considered is operated and therefore operates the pull lever 8 and the heald frame associated therewith (line V of the diagram in fig. 8).

At the end of the angular displacement of the shaft 1, the pawl 4 is placed opposite the beak 12a of the hook 12, which beak is elastically engaged in the notch 3a. At this time and if, as has been assumed, the electromagnet 19a is still energized, the selector 23 remains stuck against the poles of said electromagnet, so that when the chassis is lowered 20-21 this selector will again actuate the hook 11 this actuation will however have no effect since at this moment the pawl 4 can only be actuated by the hook 12. The latter not being controlled, the spout 12a remains engaged in the notch 3a and therefore retains immobile the plate 3 and the eccentric 2. The pull lever 8 remains in the anterior position corresponding to the lifting of the heald frame, as shown in the diagram.

On the other hand, if for the following period, the reading device 17 has ceased to excite the electromagnet 19a, the selector 23 takes off therefrom during the upward stroke of the chassis 20-21 (fig. 5) , so that when this chassis performs its downward stroke according to fig. 6, the nose 23a actuates the tail of the hook 12. The spout 12a is extracted from the notch 3a and the pawl 4 elastically introduces its spout 4a into the corresponding notch 9a of the disc 9. As a result of the drive of the eccentric 2 thus operated, the connecting rod 5 returns to its initial position and the corresponding heald frame moves.

During the upward stroke of the chassis 20-21 the heel 23b of the selector 23 comes to bear against the stop 26a (fig. 7), so that this selector is automatically controlled to tilt so as to come to stick against the poles of the electromagnet 19a. Under these conditions it is clear that this selector may or may not be retained by the electromagnet according to the desired command for the connecting rod.

It is finally understood that the arrangement according to the invention allows the control of the dobby without the electromagnets enclosed by the block 19 having to exert a force greater than that exerted by the return spring 25 of each selector 23.

Fig. 9 schematically illustrates the application of the control device according to the invention to a dobby of the type with scales. It will be recalled that in such a dobby each of the pulling levers 8 associated with the heald frames is coupled to a lever or half-balance 27 which pivots at 28 and which carries a balance 29 at articulation. Each balance 29 is formed by a sort of double lever provided at each of its ends with a coupling hook 30, respectively 31. Against the rear heel of each hook 30, 31 of the balance 29 comes to rest cyclically on a cross member 32, respectively 33, these two cross members being mounted on a flange 34 animated by an oscillating movement.

In front of each balance 29 are provided two fixed axes 35 on each of which pivots a retaining hook 36, 37 intended to cooperate with the coupling hook 30, respectively 31 of the balance. A spring 38 tends to hold the hooks 36 and 37 in an external position for which they are able to come to engage with the hooks 30 and 31, stops 39 limiting the angular displacement of said hooks 36 and 37.

The device according to the invention comprises, as in the previous embodiment, a frame 40 fixed on a shaft 41 driven by an oscillating movement. This chassis supports a block 42 identical to that referenced 19, as well as an axis 43 on which are mounted idle a number of selectors 44 equal to that of the electromagnets 42a of the aforementioned block. A spring 45 tends to keep each selector 44 in contact with a fixed stop 46.

As best illustrated in fig. 10 to 13, each selector 44 is provided with two opposite extensions 44a, respectively 44b, in order to ensure the actuation of the retaining hooks 36 and 37, provided for this purpose with a spout 36a, respectively 37a; it should be observed that these spouts 36a and 37a are arranged on the hooks 36 and 37 behind the pivots or fixed axes 35, so that when said hooks are pushed back by the spout associated with them, their useful part, c 'that is to say, their end which is intended to cooperate with the corresponding coupling hook 30, 31, is moved outwards, thus moving away from this latter hook.

• - la ligne I montre le déplacement alternatif du flasque 34 et l'actionnement des deux traverses 3£ et 33 qui agissent sur la balance 29 ;
• - la ligne II montre le déplacement alternatif de l'arbre 41 qui porte le châssis 40 et le bloc 42 ;
• - la ligne III montre le débattement angulaire du sélecteur 44 envisagé (le point bas correspondant au collage contre les pôles de l'électro-aimant 42a) ;
• - et la ligne IV montre l'alimentation de cet -électro-aimant 42a (le trait continu correspondant à l'alimentation) ;

The operation will be very briefly explained with reference to figs. 10 to 13 and fig. 14 which shows the movement diagram for a particular armor. This diagram is similar to that of FIG. 8 in the sense that:

• - Line I shows the alternating movement of the flange 34 and the actuation of the two crosspieces 3 £ and 33 which act on the scale 29;
• - Line II shows the reciprocating movement of the shaft 41 which carries the frame 40 and the block 42;
• - Line III shows the angular movement of the selector 44 envisaged (the low point corresponding to bonding against the poles of the electromagnet 42a);
• - And line IV shows the supply of this electromagnet 42a (the solid line corresponding to the supply);

In fig. 10 the chassis 40 is shown in downward travel with the selector 44 glued against the electromagnet 42a. The extension 44b escapes the spout 37a of the retaining hook 37 which is therefore not operated, so that the lower coupling hook 31 is taken while controlling the lever 8 and the corresponding heald frame. Fig. 11 shows that in the same way the upper hooks 36 and 30 remain stationary when the selector 44, always retained against the electromagnet 42a assumed to be powered, moves upwards with its extension 44a in the retracted position relative to the spout 36a.

By cons in fig. 12 the selector 44 has been assumed to be returned to the position not bonded by the spring 45, the electromagnet not being supplied; the extension 44b comes, during the downward stroke of the chassis 40 and of the selector 44, to bear against the spout 37a of the retaining hook 37. Under these conditions the latter rocks inwards and thus escapes from the hook balance hitch 31.

The situation is the same in fig. 13 where the selector 44, not retained by the electromagnet 42a, is shown during the upward stroke of the chassis 40, in order to push the spout 36a and to retract the upper hook 36 relative to the coupling hook 30.

If we look at fig. 12 and 13 as well as fig. 9 which shows the moving parts at a medium position, it can be seen that during the return movement of the oscillating frame 40 with the selector 44 in the detached position relative to the electromagnet 42a, the profiled part 44c of the edge of this selector which cooperates with the fixed stop 46 automatically returns the selector to the position glued against the poles of the electromagnet 42a, so that the latter can, if the armor program requires it, retain the aforementioned selector.

It should moreover be understood that the above description has been given only by way of example and that it in no way limits the field of the invention from which one would not depart by replacing the execution details described by all other equivalents. It will be observed in particular that if the mobility of the block of electromagnets and the selectors makes it possible to bring the latter back to the glued position by means of stops 26 rigidly fixed in the casing, it is in certain cases possible to have uses suitably controlled movable stops.

Claims (4)

1. Electro-magnetic device for controlling the dobby and other weaving mechanics, of the type comprising a reading apparatus for reading the weaving program (17) connected to electromagnets (19a, 42a) for operating the pair of hooks (11-12, 36-37) which control the amplifier system of each of the mechanical blades, characterized in that all of the electromagnets (19, 42) are fixed on a single chassis (20- 21, 40) which is driven by an oscillating movement linked to that of mechanics and which carries at each blade a selector (23, 44) associated with elastic means (25, 45) tending to separate it from the poles of attraction of the corresponding electromagnet (19a, 42a), which selector, thus driven by an alternating movement which approaches it and moves it cyclically away from the tails of the actuating hooks (11-12, 36-37 ) of the pair concerned, cooperates with a stop (26a, 46) which sticks it against the aforementioned poles when it moves away from the tails are mentioned above while it is removed from said poles. 2. Device according to claim 1 for controlling a dobby of the rotary type, characterized in that each selector (23) comprises on the one hand an axial nose (23a) which selectively comes to bear against the tail of one or on the other of the two hooks (11 or 12), and on the other hand a lateral heel (23b) which cooperates with the stop (26a). 3. Device according to claim 1 for controlling a dobby of the type with oscillating scales, characterized in that each selector (44), disposed between the two corresponding retaining hooks (36 and 37), has on the one hand two opposite extensions (44a, 44b), capable of repelling or avoiding a spout (36a, 37a) of the corresponding hook, and on the other hand an edge (44c) profiled to cooperate with the stop (46). 4. Device according to any one of claims 1 to 3, characterized in that the stop (46) is rigidly fixed on the casing of the dobby.

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