PUSH CONTROL DEVICE FOR WEAVING NEEDLES IN A JACQUARD MACHINE

Abstract: In a push control device for weaving needles in a jacquard machine, each solenoid is of a two-layer construction consisting of a suction coil and a release coil and either each wire row (17) or wire column (18,19) is comprised of a pair of wires, so that the push control device is simple in construction and assures speedy and accurate operation.

Description: This invention relates to a push control device for weaving needles in a jacquard machine and, more particularly, to an improved push control device for weaving needles in a jacquard machine which permits satisfactory back-and-forth movement of a movable core for pushing weaving needles in a jacquard machine through solenoid excitation. (Problems of the Prior Art) A needle-push control device of this sort, such as one previously developed by the present applicant, has been known. The known push control device is such that, as Figs. 5(a) and 5(b) show, latch-type solenoids 3a ... of one layer construction are connected to wire rows 17a ... and wire columns 18a ... arranged in a matrix fashion; and for example, a voltage different from that applied to wire columns 18a ... is applied to wire rows 17a ... and by changing the polarity of the voltage applied to the wire columns 18a ... the solenoids 3a are selectively excited for individual rows or columns thereby to move the movable cores 10a ... back and forth. According to such control device, by applying a given voltage to the wire rows 17a ... and wire columns 18a ... arranged in a matrix fashion, a plurality of solenoids 3a ... can be excited; and therefore, the device provides advantages that the electric capacity requirement can be reduced and that the control circuit can be simplified and thus the device can be of a compact arrangement. However, in the prior-art push control device for weaving needles, it is required that in order to excite solenoids 3a ... to move the movable cores 10a ... back and forth, a voltage different from that applied to the wire columns should be applied to the wire rows 17a ... and further the voltage applied to the wire columns 18a ... be changed over to a voltage of a different polarity, for example, from - 12V to + 12V or vise versa. That is, separate power supply sources for application of three different voltages are required. Another difficulty is that in order to change the directions of current in the wire rows 17a ... and wire columns 18a ..., two transistors 26, 26 each must be connected to the wire rows 17a ... and wire columns 18a .... Furthermore, the prior-art device involves a fatal problem that when voltages of different polarities are applied to the wire columns 18a ... arranged in a matrix fashion, as Fig. 5(b) shows, a so-called internal reflux current in the direction of arrow B flows through solenoids 3a ... to adjacent wire columns 18b to which a voltage of a different polarity is applied and, therefore, the solenoids 3a ... cannot properly operate. It is noted that this problem may be overcome by delaying in time the application of voltages of different polarities; however, this requires a very complicated circuit arrangement and makes voltage application very troublesome. SUMMARY OF THE lNVENTION This invention is directed to overcoming the foregoing problems with the prior art, and accordingly it is an object of the invention to provide a push control device for weaving needles in a jacquard machine which simplifies the construction of the device while maintaining the above stated advantage of the prior-art arrangement, and which assures speedy and accurate operation. In order to accomplish this object, in accordance with the invention a push control device for weaving needles in a jacquard machine is provided wherein voltage is applied to wire rows 17 and wire columns 18 arranged in a matrix fashion in order to excite latch-type solenoids 3, whereby movable cores 10 for pushing the needles can be moved back and forth, said device being characterised in that the solenoids 3 are of a two layer construction comprsing a suction coil 4 and a release coil 5, and in that either the wire rows 17 or the wire columns 18 are each comprised of two wires. In the push control device for weaving needles having such characteristic features, if each wire column is comprised of two wires, a given voltage is applied to one of the column wires 18 ... and a voltage of a different value from that applied to the one column wire 18 is applied to the wire rows 17 ..., whereupon current flows in the suction coil 4 of each of the solenoids 3 ... and accordingly a magnetic field is developed through the solenoid 3 so that each of the movable cores 10 ... moves forward and the movable core 10 is sucked onto the latch-type solenoid 3. On the other hand, when the voltage is likewise applied to the other of the column wires 19, current flows in the release coil 5 of the solenoid 3, whereupon a magnetic field is developed through the solenoid 3 so that the condition of the movable core 10 being sucked onto the solenoid 3 is released, the movable core 10 being thus allowed to move back to its projecting position. As stated above, according to arrangement of the invention, solenoids of a two-layer construction having a suction coil and a release coil are connected to a wiring arrangement of a matrix fashion in which either the wire rows or the wire columns are each comprised of two wires, and this provides the following advantages: (a) that a voltage of same potential is selectively applied to either the wire rows or the wire columns, which are each comprised of two wires, whereby magnetic fields of different directions are developed through each two-layer solenoid, which fact prevents the development of an internal reflux current across individual wire columns which has often occurred with the prior art arrangement; accordingly the solenoids can be accurately and positively excited and satisfactory forward movement of the movable cores is assured; (b) that whereas it has hitherto been required that two transistors be connected to each wire row, according to the invention wherein voltage of same potential is applied, it is only required that one transistor is connected to the wire rows, which fact permits simplicity in construction; (c) that by selectively applying a voltage of same value to wire rows or wire columns which are each comprised of two wires, movable cores can be moved back and forth through the solenoids; therefore it is not necessary to change over to a voltage of a different potential for voltage application to wire colums as in the case of the prior art arrangement, which fact provides a great advantage that only one kind of voltage is required for voltage application; and (d) that by virtue of the two-layer solenoid construction according to the invention, temperature rise at the solenoids during power conduction due to voltage application can be reduced as compared with the prior-art arrangement; therefore it is possible to operate the control device in favorable condition for a long period of time. (e) that since high speed control of the movable cores is possible, improved efficiency can be obtained in a series of weaving operations. BRIEF DESCRIPTION OF THE DRAWINGS Figs. 1 through 3, inclusive, illustrate one embodiment of the present invention: Fig. 1 is a schematic plan view of a push control device for needles; Fig. 2 is a partial sectional view of a latch type solenoid; and Fig. 3 is a schematic circuit diagram showing solenoids connected to a matrix wiring arrangement; Fig. 4 is a fragmentary schematic front view showing another embodiment; and Figs. 5(a) and 5(b) illustrate the prior art arrangement, Fig. 5(a) being a partial sectional view of a latch-type solenoid, Fig. 5(b) being a schematic circuit diagram showing solenoids connected to a matrix wiring arrangement. DETAILED DESCRIPTION OF THE INVENTION One embodiment of the invention will now be described with reference to the accompanying drawings. In Fig. 1, numeral 1 designates a needle-push control device mounted to a jacquard machine having laterally projecting needles 2 ... arranged therein, the push control device being back and forth movable in a direction toward the jacquard machine (direction of arrow A) by the action of shifting means (not shown). Numerals 3 ... designate "latch type" solenoids arranged in stepped fashion in the push control device 1 correspondingly to the positions of the front ends of the needles. As Fig. 2 shows, each solenoid is of a two layer construction consisting of a suction coil 4 and a release coil 5 wound in a direction opposite to the suction coil 4 and placed inner side thereof. One end of the suction coil 4 is connected to a terminal pin 6 and the other end thereof is connected, together with one end of the release coil 5, to a terminal pin 7. The other end of the release coil 5 is connected to a terminal pin 8. A permanent magnet 9 is attached to the front end of each solenoid 3. Numeral 10 designates a generally rod shaped movable core which is back and forth movably inserted in each solenoid 3 through a coil spring 11, the movable core being formed at its upper end with a push portion 12 through a collar portion 20. In Fig. 1, numeral 13 designates a fixing member for fixing the solenoid 3 in position within the push control device 1, which has a passage hole 14 bored for access of the corresponding needle 2 thereto and a hole 15 bored for access thereto of the push portion 12 of the movable core 10 inserted in the solenoid 3, the holes crossing each other. In Fig. 3, numeral 16 designates a voltage supply circuit for supply of voltage to the solenoids 3 ... which comprises wire rows 17 ... and pairs of wire columns 18, 19 arranged in a matrix fashion. Terminal pins 7 secured to the solenoids 3 are individually connected to the wire rows 17, and terminal pins 6 are each connected to one wire column 18, and terminal pins 8 each to the other wire column 19, through lead wires and diodes 25, 25. The arrangement of the push control device for weaving needles of the present embodiment has now been described. Nextly, the manner of operation of the device will be explained. Any wire columns 18 ... to which suction coils 4 are connected at one end through terminal pins 6 ... are grounded through NPN type transistors 22, and then a voltage of + 24V is applied from a power supply unit 23 to wire rows 17 ... through PNP type transistors 21 .... Thereupon, a magnetic field is formed across the suction coils 4, so that the movable cores 10 ... moves forward against the biasing force of a coil spring 11 and the collar portion 20 at the front end of each movable core 10 is sucked onto the permanent magnet 9. Then, application of the voltage is stopped. In this case, despite the voltage application to the wire rows 17 ... being stopped, the condition of the collar portion 20 of each movable core 10 being sucked onto the permanent magnet 9 is maintained at each solenoid 3, which fact enables the reduction of the electric capacity requirement. Subsequently, when condition of the movable core 10 being sucked onto the permanent magnet 9 is to be removed, the wire columns 19 ... to which one end of each release coil 5 is connected through terminal pin 8 are grounded. Thereupon, a magnetic field of an opposite direction to that due to the suction coil 4 is developed by each release coil 5, so that the suction of the movable cores 10 ... is released and accordingly each of the cores is biased by the coil spring 11 for return to its projecting condition. In this way, voltage is applied to any desired wire rows 17 ... and wire columns 18, 19 ... according to the fabric pattern to thereby excite solenoids 3 ..., whereby it is possible to selectively move the movable cores 10 ... back and forth. Subsequently, in such condition as shown in Fig. 1 in which the movable cores 10 ... have been selectively moved, the push control device 1 is moved by the shifting means in the direction of arrow A, whereupon while needles 2 ... are pushed by the projecting cores 10 ..., needles 2 ... corresponding to the movable cores 10... being sucked onto the permanent magnets 9 of solenoids 3 are allowed to enter the corresponding holes 14 without being pushed. In this embodiment, each solenoid 3 consists of two layers of a suction coil 4 and a release coil 5, and wire columns are formed in pairs. Therefore, when a voltage is applied to pairs of wire columns 18, 19, that is, a voltage of + 24V is applied to wire rows 17 ..., it is possible to move the movable cores 10 back and forth by selectively grounding the wire columns 18, 19 .... Thus, solenoids 3 can be satisfactorily excited to move the movable cores 10 ... back and forth without internal reflux current being produced across the wire columns 18 .... Further, as stated above, wire columns 18, 19 ... only require application of a voltage of same potential or being grounded and, therefore, it is only necessary that one transistor be connected to the wire row 17, which fact provides an advantage of simplified circuit arrangement. In the above described embodiment, each wire column is comprised of two wires 18, 19, but alternatively each wire row 17 may be comprised of two wires. It is only required that either each wire row or wire column be comprised of two wires. In the embodiment, wire columns 18, 19 are grounded and wire rows 17 ... are subjected to application of a voltage of + 24V; but the wire columns 18, 19 should not necessarily be grounded. It is only required that different voltages be applied to the wire rows and columns to provide a voltage difference, no particular value being specified for the voltage to be applied. The push control device of the invention is not limited to the use for lateral needle push control as in the above described embodiment; needless to say, it can be used for push control of any other type of weaving needles. In the above embodiment, lateral needle 2 is pushed directly by movable core 10; but alternatively it is possible, for example, to arrange that, as Fig. 4 shows, the lateral needle 2 is pushed indirectly by the movable core 10, with a push rod 24 interposed between the needle and the core.

Claims: A push control device for weaving needles in a jacquard machine wherein voltage is applied to wire rows 17 and wire columns 18 arranged in a matrix fashion in order to excite latch-type solenoids 3, whereby movable cores 10 for pushing the needles can be moved back and forth, said device being characterised in that the solenoids 3 are of a two layer construction comprising a suction coil 4 and a release coil 5, and in that either the wire rows 17 or the wire columns 18 are each comprised of two wires.

Inventors: AOKAWA, MASARU, TAKEMURA, KUNIHIRO
Applicants: KABUSHIKI KAISHA TAKEMURA SEISAKUSHO
Application year: 1989
Main classification: D03C3
IPC codes: D03C13, D03C3