Device for driving the reed in a loom, method for driving the reed and loom with such a device

Abstract: The device for driving the reed (13) in a loom is completely independent from the main motor (40). A separate motor (30) for driving the rocking shaft (10) on which the reed (13) is fixed, is controlled according to the desired idividual operating conditions by a control system (50, 57). The method of driving the reed (13) consists in driving the rocking shaft (10) with the reed (13) independently from the main motor (40) for driving other systems of the loom. The loom is including an individual drive (30) for the rocking shaft (10) with the reed (13).

Description: The present invention relates to a device for driving a reed in a weaving loom, a method for driving the reed and further to a loom with such a device. If the time for weft picking is set longer in one cycle of loom operation, the weft picking can take place during a longer period of time and, therefore, weft feeding and weft tension controlling can be performed advantageously, with the result that fabrics with better quality can be produced. However, if this is simply arranged in a way that starting of weft picking takes place at an earlier time, there is a tendency that the weft yarn itself or the weft carrier contacts slightly the warp threads because of insufficient retraction of the reed and/or insufficient opening of the warp shed, thereby causing various troubles such as: weft picking being susceptible to the resistance by warp yarns; warp threads being damaged; warp yarns being cut; and/or array of warp yarns being distrubed, and these troubles may result in failure in weft picking. Various improvements have been proposed so far as to prevent such troubles. The Japanese patent application 58-191247 e.g. discloses a so called multi-joint link type drive for the reed and shaft. According to this arrangement, the uniform rotational movement of a crankshaft is converted into a reciprocating motion of the rocking shaft by a link mechanism that influences the movement of the reed in a way that the time for weft picking is more advantageous compared to a sinus-type reed motion. In multi-joint link drives however, the reed is at a stop only apparently at its retracted position, but the reed is acutally vibrating there, so that a considerable amount of load tends to be applied to the various parts of the device. This results in a considerable loss of power and requires the parts to be strong enough to resist such load. With the increased number of components in the loom taken into account this reed drive device is not suitable for high-speed operation of the loom. The Japanese patent application 54-10662 discribes a so called positive cam type reed shaft drive. According to such an arrangement, the uniform rotational movement of the crankshaft is converted into a reciprocating motion of the rocking shaft by a the cam lever which slidably rides on the positive cams. By profiling the positive cams, so as to provide a defined angle of repose, an irregular movement of the reed, desirable for securing longer time for weft picking is achieved. In the positive cam type reed shaft drive it is extremely difficult to thoroughly eliminated the gaps between the positive cams the cam followers. Gaps cause intolerable noise and heat build-up during high-speed operation of the loom. Thus, this method is not suitable for high-speed operation of the loom, either. Further when it is desired to operate the loom with different weaving conditions, e.g. different kinds of weft yarns for picking, different weaving width, etc., in reed shaft drives as described above, it becomes necessary to make troublesome setup changes which would require changing the angle of repose at the reed's retracted position. With the reed drive system of the multi-joint link type, levers and connecting rod must be changed; with the device of the positive cam type, the positive cams and cam followers calls for changing. However, such changing of parts to cope with the change of weaving conditions are practically not feasible. Thus, the conventional reed driving devices are also inconvenient in that setup changes can not be made easily. DE-A-37.23.433 discloses a ribbon loom with a motor that drives a rocking shaft system with a V-shaped reed, together with a knitting needle the for securing the inserted wefts. This knitting needle cooperates with the picking needle. Varying the rocking speed of the shaft system is only possible if the reciprocating speed of the picking needle is varied by the same rate. EP-A-0.298.454 describes a reed operating system for a loom, wherein the advance position of the reed can be altered by rotation of a cranked shaft by means of a hydraulic cylinder. FR-A-2.359.917 discloses a reed operating system of a loom whose reciprocating speed is determined by springs. The amount of energy lost during one rocking cycle is added by a fluid driven piston in a cylinder. The frequency of the rocking reed is constant and determined by the springs. It is an object of the present invention, therefore, to provide reed drive and a method of driving a reed in a weaving loom which offers smooth driving of the reed shaft in high-speed operation of the loom and further provides for versatility to cope with varying weaving conditions. and requirements. In order to solve the above-mentioned problems, the invention provides for a device for driving the reed that is characterized by the features of claim 1 and further provides for a method that is characterized by the features of claim 5. The loom according to the invention is characterized by the features of claim 7. The dependent claims are related to particular embodiments of the invention. The main motor, when referred to in the present invention, means specifically a motor other than the motor used to supply power for driving the reed of the loom. The variable-speed motor, which is provided independently of drive systems driven by the main motor and used to supply power to the rocking shaft drive system, is controlled by a control device. Rotation of the rocking shaft in forward direction causes the sley to move toward the cloth fell/cloth beam (Warenbaum) for beating-up operation of the reed. Rotation of the rocking shaft in reverse direction causes the sley to move toward its retracted position. Such reciprocatory rotary movement of the rocking shaft is accomplished by a mechanism provided for the rocking shaft drive system and adapted to change the rotational direction of the rocking shaft or by changing the operational direction of the variable-speed motor. The speed and timing of beating-up operation and the speed of reed movement can be controlled easily by electrically and/or electronically controlling the reed drive motor. In the following the invention will be explained and descirbed on behalf of embodiments of the reed drive and with reference to the schematic drawings and diagrams. Fig. 1 to 4 show a first embodiment of the invention, adapted for use in an air jet loom (Fig. 1), a blockdiagram and a signal processing flow chart of the electonic control system (Fig. 2 and 4) and further a beating-up diagram of the reed driving system (Fig. 3); Fig. 5 and 6 show a second embodiment of the invention that is also adapted for use in an air jet loom and its signal processing flow chart; Fig. 7 shows a third embodiment of the invention that is also adapted for use in an air jet loom; Fig. 8 is a diagram exemplifying beating-up curves for different kinds of weft yarns; Fig. 9 and 11 show two schematic examples of reed drive devices according the prior art; Fig. 10 is a diagram exemplifying a beating-up curve of a conventional device according to the prior art; According to Fig. 1 a reciprocating rotatable rocking shaft 10 disposed extending across the loom has a sley sword 11 and a rocking arm 15 fixedly mounted thereon for reciprocating with the rocking shaft 10. The sley sword 11 has a sley 12 fixed thereto and having a reed 13 with a guide dent forming a weft guide passage 14. A connecting rod 21 is slidably connected at its distal end 22 to the rocking arm 15. The reed 13 may be substituted with an ordinary reed having no guide dents or guide channel. There is a crankschaft 20 to which the proximal end 23 of the connecting rod 21 is eccentrically and slidably mounted. The crankshaft 20 is driven by a variable-speed motor 30. The power of the motor 30 is transmitted to the crankshaft 20 by any suitable means such as gears, chain, rod, etc. Though no limitation is intended, a timing belt 31 is used in the embodiment for transmitting the power of the motor 30 to the crankshaft 20. The variable-speed motor 30 is driven under the control of a control device 50 through a speed control device 57. The control device 50 is adapted to receive detect signals from a rotary encoder 35 for detecting the angle of rotation of the variable-speed motor 30 and also detect signals from a rotary encoder 45 for detecting the angle of rotation of a main motor 40. Instead of the variable-speed motor 30 it would also be possible to use e.g. a controlled variable-speed transmission or transmission gear. Reference is now made to Fig. 2 which shows a control circuit for controlling the driving operation of the variable-speed motor 30. The control device 50 has a microcomputer 51 which includes a central processing unit 52 (hereinafter referred to as "CPU"), a program memory 53, or a read-only memory (ROM), for storing therein a control program, and a work memory 54, or a random access memory (RAM), for temporarily storing the processing results of the CPU 52. The CPU 52 operates from the control program data stored in the program memory 53. The control device 50 further includes a keyboard as an input device 55 for inputting into the microcomputer 51 data of various weaving conditions and weaving requirements, such as kind of weft yarn, weaving width, loom speed, etc. The CPU 52 is adapted to calculate for an optimum reed motion on the basis of the data on the kind of weft yarn to be used, weaving width, loom speed, etc. which are inputted into the CPU 52 from the input device 55 prior to starting of the loom operation. For example, when a reed motion is calculated by the CPU 52, as indicated by the solid line in the diagram of Fig. 3, the CPU compares and processes the signals by detected the rotary encoders 35, 45 thereby to transmit to the speed control device 57 a control signal for correcting and controlling the operation of the variable-speed motor 30 in such a way, that it operates in accordance with the solid curved line in the diagram. The following will describe the operation of the reed driving device having the construction as illustrated above. According to a drive command from the control device 50, the speed control device 57 causes the variable-speed motor 30 to rotate. As the motor 30 starts rotating, the rocking shaft 10 is driven thereby to make reciprocatory rotation via the belt 31, crankshaft 20, connecting rod 21 and rocking arm 15. The sley sword 11, sley 12 and reed 13 are moved together with the rocking shaft 10 for beating-up motion of the reed 13. Varying positions of the reed 13 are detected by the rotary encoder 35 mounted on the variable-speed motor 30 and pulse signals corresponding to the reed positions are transmitted to the control device 50. The movement of component parts of the loom which are driven by the main motor 40 is detected by the rotary encoder 45 mounted on the main motor 40 and pulse signals representing the motion of each such part are also transmitted to the control device 50. The control device 50 operates in accordance with the flow chart provided in Fig. 4 to control the reversible variable-speed motor 30 so that it operates following the optimum beating-up curve calculated from the data on weaving conditions fed into the work memory 54 and stored in advance before starting the loom operation. Just prior to starting the loom operation, the rocking shaft 10 and the main shaft (not shown) driven by the main motor 40 are positioned relative to each other for initial start-up. Then, making sure that loom stop command is not present, the loom operation is started. During the loom operation, the control device 50 constantly compares the pulse signals from the rotary encoders 35 and 45 and controls the rocking motor 30 while adjusting its operation as required so that the rocking motor operation follows the stored optimum beating-up curve. When a loom stop command is provided due to any abnormality in operation or by the loom operator, the loom is stopped and set in a stand-by state. If the loom abnormality is removed and loom re-start command is issued, the rocking shaft and the main shaft are driven again from the initial start-up position. For weft picking to be accomplished successfully, it is desirable that the reed should move as little as possible while a weft yarn is being inserted/blown through the shed. According to this embodiment of the invention, the reed movement can be adjusted according to the ease of weft insertion. Furthermore, because the ratio of time for weft picking in one cycle of loom operation can be adjusted, it is possible to weave a variety of fabrics by a single loom. Further the drive system for reed beating-up according to the present invention is thus simpler in construction than in conventional systems. The device according to the invention is advantageous with regard to the reduction of heat build-up, noise and vibration, operating efficiency, etc. Accordingly, the present invention allows for further speed-up of loom operation. In another embodiment of the invention, shown in Fig.5, a motor operable in both forward and reverse directions, e.g. a servo motor 32, is employed as the variable-speed motor. This embodiment thus differs from the first embodiment in details of the beating-up motion drive system. Referrening to Fig. 5, the sley sword 11, sley 12 and reed 13 are disposed on the rocking shaft 10 in the same arrangement as in the above-described first embodiment. The rocking shaft 10 is driven by the servo motor 32 by way of a timing belt 33. As mentioned with reference to the first embodiment, it is to be noted that means for transmitting power of the motor 32 to the rocking shaft 10 of course is not limited to the timing belt only. The control circuit 50 for controlling the operation of the servo motor 32 operates in accordance with the flow chart shown in Fig. 6. This flow chart differs from that provided in Fig. 4 in respect of the portion for controlling the reciprocating rotation of the rocking shaft 10, but other portions thereof are substantially similar to the corresponding portions of the flow chart in Fig. 4. As the loom starts its operation, the control device 50 responds to the pulse signals from the rotary encoder 45 to integrate the main shaft angle Θ. After making sure that loom stop command is not present, the direction in which the rocking shaft 10 is then rotating, forward or reverse, is determined. Then, the control device 50 controls the rocking motor 32 so that it operates in compliance with the stored optimum beating-up curve until a condition Θ > Θ1 is reached if the rocking shaft 10 is then rotating in forward direction, or until a condition Θ > Θ2 is reached if the rocking shaft is then rotating in reverse direction, wherein Θ1 represents a main shaft angle at the moment of beating-up, and Θ2 a main shaft angle at which the reed is just about to move from the retracted position toward the cloth fell. When the main shaft angle reaches either Θ1 or Θ2, the servo motor 32 receives a reverse command and accordingly changes its rotational direction to reverse the rocking shaft 10. With respect to the other arrangements, this embodiment operates in the same manner as the first embodiment. The particular features of a third embodiment shown in Fig. 7 can be seen in the structure for feeding weft yarns. The other structures are similar to those of the first or second embodiment shown in Fig. 1 and 5. On one end (or weft picking side) of the rocking shaft 10 is fixedly mounted a nozzle holder 60 in which there are two weft picking nozzles 61, 62 for injecting weft yarns Y1, Y2 from a weft supply (not shown) into the weft guide passage 14. The nozzle 61 is connected to a compressed air tank 67 via a flexible pipe 63 and an electromagnetic valve 65, while the other nozzle 62 is connected to a compessed air tank 68 via a flexible pipe 64 and an electromagnetic valve 66. In response to a command generated according to a picking pattern preset by a weft picking control circuit (not shown), either one of the elctromagnetic valves 65, 66 is openend to release its weft yarn Y1 or Y2. In this way, the order in which the weft yarns Y1 and Y2 are picked is controlled according to the preset picking pattern. In a loom having the above arrangement, the pressures of air from t he two picking nozzles 61, 62 can be controlled independently of each other and also the beating-up curve can be established as required, so that the two weft yarns Y1 und Y2 do not have to be of a similar type in characteristics, but they may be of different types, e.g. one being a cotton yarn and the other being a silk yarn. As exemplified by the diagram in Fig. 8, the desired pattern of beating-up curve may vary with the kind of weft yarn to be picked. By changing and controlling the beating-up curve for each kind of weft yarn according to a predetermined picking pattern, however, fabrics woven by a combination of several kinds of weft yarns and this even with combinations that could not be thought of with conventional looms, can be produced with the new loom. As is apparent to those skilled in the art, the number of weft picking nozzles used in the above embodiment is not limited to two only, but three or more nozzles may be used for picking three or more different of weft yarns even of a different type, for example by adding a pattern of beating-up curve for woolen weft yarn, as indicated in Fig. 8. It is to be noted that the reed driving device of the present invention is not limited to the embodiments illustrated in the above, but it may be used in combination with shuttleless looms other than air jet looms, and also with looms using a shuttle. Though the rotary encoder 35 is mounted on the motor in the embodiments, it may be mounted on the crankshaft 20 or rocking shaft 10. The rotary encoder itself may be substituted by other detecting means such as a resolver. The same applies also for the other rotary encoder 45, which may be substituted by a resolver mounted on the main shaft. Furthermore, the control device 50 may be arranged in a way that a plurality of patterns of beating-up curves, e.g. three patterns as exemplified in Fig. 8, can be stored in the program memory 53 so that the operator may select the desired pattern. Alternatively, the control device 50 may be simplified by dispensing with the input device 55 so that the loom operates always from a predetermined pattern of beating-up curve. The arrangement according to the prior art, shown in Fig. 9, is referred to as multi-joint link type, and disclosed, e.g., by Japanese patent application 58-191247. According to this device, the uniform rotational movement of the crankshaft 101 is converted into a reciprocatory rotary motion of the rocking shaft 103 through the link mechanism 102. Provision of the lever 112 permits an irregular movement of the reed, as shown by solid line in Fig. 10, thereby to secure the time for weft pcking more advantageously as comopared with the reed motion, as indicated by dashed line in Fig. 10, which had been realized by standard crank mechanism. Another arrangement according to the prior art, shown in Fig. 11, which is referred to as positive cam type, is disclosed in Japanese patent application 54-10662. According to this arrangement, the uniform rotational movement of the crankshaft 105 is converted into a reversible rotational motion of the rocking shaft 109 through the cam lever 108 which slidably rides on the positive cams 106, 107. By profiling the positive cams 107, 107 so as to provicde an angle of repose, an irregular movement of the reed, as shown in Fig. 10, desirable for securing longer time for weft picking is achieved. When it is desired to operate the loom with different weaving conditions, e.g. different kinds of weft yarns for picking, different weaving width, etc., it becomes necessary to make troublesome setup changes which would require changing the angle of repose at the reed's retracted position. With the reed drive system of the multi-joint link type, the lever 112 and connecting rod 113 must be changed; with the device of the positive cam type, the positive cams 106, 107 and cam followers 110, 111 calls for changing. However, such changing of parts that becomes necessary to cope with the change of weaving conditions is practically not feasible. Thus, the conventional reed driving devices are inconvenient in that setup changes cannot be made easily if at all. As it is apparent from the foregoing description, the present invention can solve the aforementioned problems inherent to the conventional reed driving methods and devices, such as heat build-up, development of noise and vibration, and poor operating efficiency, thus making possible operation of a loom at a higher speed. The reed driving system of the invention provides for a loom which is capable of flexibly coping with weaving fabrics having a larger width and/or also wovens with weft yarns of different types, which could not be manufactured with the conventional looms so far. Additionally, because the reed movement is electrically controlled, independent of the movement of other major parts of the loom, the beating-up curve can be established with a high degree of freedom. This can make it possible to produce woven by an unprecedented combination of different kinds of weft yarns. The device for driving the reed in a loom is completely independent from the main motor. The separate motor for driving the rocking shaft on which the reed is fixed, is controlled according to the desired idividual operating conditions. The method of driving the reed consists in driving the rocking shaft with the reed independent from the main motor for driving other systems of the loom. The loom is including an individual drive for the rocking shaft with the reed. BRIEF EXPLANATION OF THE DRAWINGS Of Figs. 1 through 8 showing the embodiments of the present invention: Fig. 1 is a schematic side view showing the first embodiment of the reed drive device of the invention; Fig. 2 is a block diagram showing the control device for the beating-up motion in the first embodiment; Fig. 3 is a diagram exemplifying a beating-up curve representing the positional relationship between the main shaft and the reed of the loom; Fig. 4 is a flow chart showing the operational procedure of the loom in the first embodiment; Fig. 5 is a block diagram of the control device for the beating-up motion in the second embodiment; Fig. 6 is a flow chart showing the operational procedure of the loom in the second embodiment; Fig. 7 is a partial perspective view showing schematically the weft picking device of the loom in the third embodiment; Fig. 8 is a diagram exemplifying beating-up curves for different kinds of weft yarns. Of Figs. 9 through 11 showing the beating-up motion of conventional structures; Fig. 9 is a schematic side view of a conventional beating-up motion of multi-joint link type; Fig. 10 is a diagram exemplifying a beating-up curve of the conventional device; Fig. 11 is a side view of a conventional beating-up motion of positive cam type. 10: Rocking shaft 11: Slay sword 12: Slay 30: Variable-speed motor 32: Servo motor 40: Main motor 50: Control device

Claims: Device for driving a reed (13) in a loom , comprising: a rocking shaft (10) with means (11, 12) for fixing the reed (13) on the shaft (10); a rocking shaft drive system (20, 21, 15) which is driven independently from a main motor (40) for driving systems, other than the rocking shaft drive system (20, 21, 15) of the loom, characterized in that ; a motor (30), is adapted for driving said rocking shaft drive system (20, 21, 15), and to reciprocate said rocking shaft (10) with the reed (13) fixed thereon; a control (50, 57) controls said rocking shaft drive system (20, 21, 15); the motor (30) is a variable speed motor, adapted for driving said rocking shaft drive system (20, 21, 15) by variable speed, the control (50, 57) includes a speed varying control (57) for varying the speed of the variable speed motor (30) according to the desired operating conditions of the loom. Device according to claim 1 wherein the means for fixing the reed onto the rocking shaft comprise a slay (12) and a slay sword (11). Device according to claim 1 or 2 wherein the rocking shaft (10) extends sidewards of the warp and/or the reed (13) of said loom. Device according to any of claims 1 to 3 wherein the variable-speed motor (32) is a forward backward reciprocating operated servo motor. Method for driving the reed (13) of a loom by reciprocating a rocking shaft (10), on which the reed (13) is fixed, said rocking shaft (10) being reciprocated; by a shaft drive system (20, 21, 15), independent from the main motor (40) for driving systems of the loom, other than the rocking shaft drive system (20, 21, 15); characterized by reciprocating the rocking shaft (10) via the shaft drive system (20, 21, 15) with a variable speed motor (30), according to desired operating conditions of the loom, the variable speed motor (30) being controlled by a variable speed control (57) Method for driving the reed (13) of a loom according to claim 5, with a device according to any of the claims 1 to 4. Loom with a device according to any of the claims 1 to 4 for rocking the shaft (10) and the reed (13) with variable speed.

Inventors: SHINBARA MASAMI, SHINBARA, MASAMI, SHINBARA, MASAMI, C/O KABUSHIKI KAISHA TOYODA
Applicants: TOYODA AUTOMATIC LOOM WORKS, KABUSHIKI KAISHA TOYODA JIDOSHOKKI SEISAKUSHO
Application year: 1991
Main classification: D03D49
IPC codes: D03D49