EP1420093A2

EP1420093A2 - Method of controlling an electric selvedge device and the electric selvedge device

Info

Publication number: EP1420093A2
Application number: EP03025607A
Authority: EP
Inventors: Hiroaki Hasegawa
Original assignee: Tsudakoma Industrial Co Ltd
Current assignee: Tsudakoma Corp
Priority date: 2002-11-15
Filing date: 2003-11-06
Publication date: 2004-05-19
Also published as: JP2004162226A; CN1500924A; EP1420093A3

Abstract

An electric selvedge device (10) can prevent a weft (7) at selvedge portions from loosening when forming a selvedge. The electric selvedge device (10) drives a rotary member (8) provided with a pair of guide portions (14, 15), through which different selvedge threads (12, 13) pass, by a driving unit (9), controlling the turning of the rotary member (8) by a controller (11) to turn the rotary member (8) in one direction, and to turn subsequently in the other direction, thereby forming the selvedge, wherein a twist, in which a weft (7) is not inserted, is formed by a reverse turning operation of the rotary member (8) when the controller (11) controls the rotary member (8) to be turned in reverse from one direction to the other direction.

Description

BACKGROUND OF THE INVENTION

The invention relates to a method of controlling an electric selvedge device of a loom and the electric selvedge device of the loom.
Japanese Patent No. 2933889 discloses a twist selvedge forming method using a twist selvedge device. The twist selvedge forming method uses, as shown in Fig. 1, a twist selvedge device provided with a twist disc (rotary member) 4 having two thread holes (guide portions) 5, 6 through which two twist threads (selvedge threads) 2, 3 are guided, wherein the twist disc 4 is turned in one direction, then it is turned in the other direction, i.e., opposite direction so that the twist or entanglement of the twist threads 2, 3 caused by the turning of the twist disc 4 in one direction is cancelled by the turning of the same in the opposite direction. In such a manner, each weft 7 is held between the twists of the twist threads 2, 3.
Further, the technique disclosed in JP 1999-501999A discloses a leno weaving device provided with an arm through which two entangled threads are supplied to a rotor (rotary member), wherein the rotor is turned in one direction by a specific number of revolution, then the turning direction of the rotor is reversed so that the rotor is turned in a reverse turning direction, thereby canceling the twists of the entangled threads.
According to the conventional techniques as set forth above, there is no twist caused by the selvedge threads between a weft at the selvedge portions which is inserted immediately before the rotary member such as a disc or rotor is reversed and a weft at the selvedge portions adjacent thereto, but these wefts merely cross each other. Accordingly, the wefts at the selvedge portions are prone to loosen, which causes a problem of production of ill effect on quality of the fabric.
Fig. 2 shows a drawback of the selvedge forming method as described in Japanese Patent No. 2933889, as an example, wherein the twist disc 4 is turned in reverse rightward by one revolution as the revolution in an opposite direction at 100^th pick.
In Fig. 2(1), the twist disc 4 is turned in reverse rightward by half revolution in a state where the twist disc 4 finished turning leftward by half revolution (at 100^th pick). In Fig. 2(2), the twist disc 4 is further turned in reverse rightward by half revolution. The turning in Fig. 2(1) and (2) is continuously effected. In Fig. 2(3), a next weft 7 runs toward sheddings of the twist threads 2, 3.
In Fig. 2(4), after the weft 7 passed through the sheddings of the twist threads 2, 3, the twist disc 4 is turned rightward by half revolution. From now on, the twist disc 4 is always turned rightward. After the operation in Fig. 2(5), the operations in Figs. 2(3), (4) are repeated. In Fig. 2(5), the twist threads 2, 3 are not entangled with each other before or after at 100^th pick (inside of the circle), so that the weft 7 is prone to loosen, which produces ill effect on quality of the fabric.

SUMMARY OF THE INVENTION

It is an object of the invention to prevent wefts at selvedge portions from loosening when forming the selvedge by a selvedge device of this type.
To achieve the above object, the electric selvedge device of the invention prevents wefts from loosening by forming a twist, in which the weft is not inserted, between the wefts where the selvedge portions are adjacent to each other when the rotary member for guiding the selvedge threads is turned in reverse.
More in detail, a method of controlling an electric selvedge device according to the first aspect of the invention which turns a rotary member provided with a pair of guide portions, through which selvedge threads pass, in one direction, and subsequently turns the rotary member in other direction to form a selvedge, wherein the method comprising the step of forming a twist, in which a weft is not inserted, by a reverse turning operation of the rotary member when the rotary member is turned in reverse from one direction to the other direction.
According to the second aspect of the invention, the number of revolution of the rotary member, when the rotary member is turned in reverse, can be set optionally, and according to the third aspect of the invention, the number of revolution of the rotary member, and a reverse revolution speed thereof, when the rotary member is turned in reverse, are relatively changed.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a side view of a conventional selvedge device;
Fig. 2 is a view for explaining a selvedge forming process by a conventional selvedge device;
Fig. 3 is a side view of an electric selvedge device for carrying out a method of controlling the electric selvedge device according to the invention;
Fig. 4 is a view for explaining a selvedge forming process by the method of controlling the electric selvedge device according to one example of the invention, and a table showing the relationship between the number of picks and the number of revolution;
Fig. 5 is a view for explaining a selvedge forming process by the method of controlling the electric selvedge device according to another example of the invention, and a table showing the relationship between the number of picks and the number of revolution; and
Fig. 6 is a view for explaining a selvedge forming process by the method of controlling the electric selvedge device of the invention.

PREFERRED EMBODIMENT OF THE INVENTION

Fig. 3 shows an electric selvedge device 10 for carrying out a control method of the invention. The electric selvedge device 10 is provided with a rotary member 8, a driving unit 9 and a controller 11.
The rotary member 8 has a pair of guide portions 14, 15 made up of two thread holes for guiding two selvedge threads 12, 13. Two selvedge threads 12, 13 are unwound from bobbins 16, 17, respectively, and pass through a guide 18, then pass through the guide portions 14, 15 of the rotary member 8, and finally they are entangled with each other to hold each end of the wefts 7.
The rotary member 8 is driven by a rotation transmission means 19 such as a roller, a belt and so forth of the driving unit 9 from the outer peripheral side of the rotary member 8 not to impede the twisting operation of two selvedge threads 12, 13. The driving unit 9 includes a driving motor 20 which can be changed in a turning direction, the number of revolution, and a revolution speed, and it is controlled by the controller 11. The controller 11 controls the turning direction, the number of revolution, and the revolution speed of the driving motor 20 inside the driving unit 9 based on the control method of the electric selvedge device of the invention in a state where it is synchronized with a main shaft 21 in response to set data from an input device 22.
The controller 11 controls the rotary member 8 such that it turns the rotary member 8 in one direction by a predetermined number of revolution during multiple pick to grasp the weft 7, then once turns the rotary member 8 in reverse, and then turns the rotary member 8 in the other direction by a predetermined number of revolution during multiple pick to grasp the weft 7, which operations are repeated. More in detail, according to the control method of the electric selvedge device, the driving motor 20 inside the driving unit 9 is driven for turning the rotary member 8 in one direction by the predetermined number of revolution every each pick to grasp the weft 7, and once turning the rotary member 8 in reverse, subsequently turning the rotary member 8 in the other direction by the predetermined number of revolution every predetermined number of picks to grasp the weft 7, which operations are repeated, whereby when the turning direction is reversed during the formation of the selvedge, the twist in which the weft 7 is not inserted is formed by the reverse turning operation.
Fig. 4 is a view for explaining the selvedge forming process according to the control method of the electric selvedge device of the invention and the corresponding relation between the number of picks and the number of revolution during the selvedge forming process. In Fig. 4, the control of the selvedge forming is effected such that the number of revolution of the rotary member 8 is set at one revolution when it is turned in reverse, and the turning direction of the rotary member 8 is reversed immediately after the weft 7 at the 100^th pick passes through the sheddings of the selvedge threads 12, 13. In the table shown in Fig. 4, assumes that the turning direction of the rotary member 8 is reversed every 100^th pick unit, and the leftward turning of the rotary member 8 is depicted by + and the rightward turning of the rotary member 8 is depicted by -. Assumes that the revolution speed (the number of turning) of the rotary member 8 is constant (fixed).
In the table shown in Fig. 4, since the rotary member 8 is turned leftward (+) by half revolution every pick interval of the 1^st to 99^th picks, two selvedge threads 12, 13 hold the end of the weft 7 while forming the twists. Since the rotary member 8 is turned rightward (-) by one revolution after the weft 7 crosses two selvedge threads 12, 13 at 100^th pick, two selvedge threads 12, 13 form a twist of- one revolution in which the weft 7 is not inserted between the 100^th pick and 101^st pick as shown by the inside of the circle. As a result, the looseness of the weft 7 at 100^th pick can be prevented.
Thereafter, since the rotary member 8 is turned rightward (-) by half revolution every pick interval of the 101^st to 199^th picks, two selvedge threads 12, 13 hold the end of the weft 7 while forming the twists. After the weft 7 crosses the selvedge threads 12, 13 at 200^th pick, the rotary member 8 is turned leftward (+) by one revolution, so that the selvedge threads 12, 13 form a twist of +one revolution in which the weft 7 is not inserted between the 200^th and 201^st picks. As a result, the looseness of the weft 7 at the 200^th pick can be prevented. In such a manner, the turning direction of the rotary member 8 is reversed in the cycle of 100^th pick unit, thereby forming the twist of one revolution.
Fig. 5 is a view for explaining the selvedge forming process according to another control method of the electric selvedge device of the invention and the corresponding relation between the number of picks and the number of revolution during the selvedge forming process. In Fig. 5, the control of the selvedge forming is effected such that the number of revolution of the rotary member 8 is set at one and a half revolution when it is turned in reverse, and the turning direction of the rotary member 8 is reversed after the weft 7 at the 100^th pick passes through the sheddings of the selvedge threads 12, 13, and the turning of the rotary member 8 is completed. Also in the table shown in Fig. 5, assumes that the turning direction of the rotary member 8 is reversed every 100^th pick unit, and the leftward turning of the rotary member 8 is depicted by + and the rightward turning of the rotary member 8 is depicted by -. Assumes that the revolution speed (the number of turning) of the rotary member 8 is constant (fixed).
In the table shown in Fig. 5, since the rotary member 8 is turned leftward (+) by half revolution every pick interval of the 1^st to 99^th picks, two selvedge threads 12, 13 hold the end of the weft 7 while forming the twists. Since the rotary member 8 is turned leftward (+) by half revolution after the weft 7 crosses two selvedge threads 12, 13 at 100^th pick, then turned rightward (-) by one and a half revolution, two selvedge threads 12, 13 form a twist of - one revolution (- one revolution and a half revolutions + half revolution) in which the weft 7 is not inserted between the 100^th pick and 101^st pick as shown by the inside of the circle. As a result, the looseness of the weft 7 at 100^th pick can be prevented.
Thereafter, since the rotary member 8 is turned rightward (-) by half revolution every pick interval of the 101^st to 199^th picks, two selvedge threads 12, 13 hold each end of the wefts 7 while forming the twists. After the wefts 7 cross the selvedge threads 12, 13 at 200^th pick, the rotary member 8 is turned rightward (-) by half revolution, then turned leftward (+) by one and a half revolution so that the selvedge threads 12, 13 form a twist of +one revolution in which the weft 7 is not inserted between the 200^th and 201^st picks. As a result, the looseness of the weft 7 at the 200^th pick can be prevented. In such a manner, the turning direction of the rotary member 8 is reversed in the cycle of 100^th pick unit, thereby forming the twist of one revolution.
In this case, the twist, in which the weft 7 is not inserted, is once rendered in a non-twisted state when the rotary member 8 is turned in reverse, and the rotary member 8 is turned by at least one revolution, to render the weft 7 in a shedding state to form the twist.
According to the examples shown in Figs. 4 and 5 as set forth above, since the twist in which the weft 7 is not inserted is formed when the rotary member 8 is turned in reverse, the selvedge threads 12, 13 are entangled with each other so that there is formed a twist, in which the weft 7 is not inserted, between the wefts 7 which are adjacent to each other in the selvedge portions. Accordingly, the effect of fastening of the selvedge threads 12, 13, which are entangled with the weft 7, is improved. As a result, the looseness of the wefts 7 can be prevented, contributing largely to the improvement of quality of the fabric.
Further, according to the example shown in Fig. 4, it is possible to form twists by the number of revolution which is smaller than that in the example shown in Fig. 5 by half revolution, there is improved an efficiency relative to the weaving such as cutting down the time needed for the rotary member 8 to be turned.
Further, Fig. 6 shows an example wherein the number of revolution of the rotary member 8 when it is turned in reverse can be optionally set using the controller 11 having a storage function. The controller 11 can store therein the corresponding relation between the number of revolution of the main shaft 21 of the loom (revolution speed of the loom) and the number of revolution when the rotary member 8 is turned in reverse owing to the storage function of an internal memory.
Accordingly, an operator operates the input device 22 to set the number of revolution, when the rotary member 8 is turned in reverse, e.g., at one and a half revolution in the case where the revolution speed of the main shaft 21 is equal to 800 rpm while the number of revolution of the rotary member 8, when the rotary member 8 is turned in reverse, is set, e.g., at one revolution in the case where the revolution speed of the main shaft 21 is equal to 1000 rpm.
With such a setting of the number of revolution, when the revolution speed of the main shaft 21 of the loom is changed from 800 rpm to 1000 rpm during the weaving operation, the number of revolution of the rotary member 8 when it is turned in reverse is changed from one and a half revolution to one revolution. As a result, when the revolution speed of the main shaft 21 is 800 rpm, the twist is formed two times as shown by the inside of the circle in view of the enforcement of fastening.
There are following two manners for controlling the number of revolution of the rotary member 8 when the rotary member 8 is turned in reverse. (1) The number of revolution of the rotary member 8, when the rotary member 8 is turned in reverse, is optionally set, and it is fixed during the weaving operation. This is the case as exemplified in Figs. 4 and 5. (2) Multiple number of revolution is optionally set relative to at least one of the conditions of the kind of threads, the revolution speed of the main shaft 21 of the loom, and so forth, and when the kind of threads and the revolution speed of the main shaft 21 of the loom are changed during the weaving operation, the multiple number of revolution is freely changed to the number of revolution corresponding to the changed condition every time the change of condition occurs. This is the case as exemplified in Fig. 6.
In such a manner, since the number of revolution of the rotary member 8, when it is turned in reverse, is optionally set, the entangled state of the selvedge threads can be adjusted. Further, if multiple number of revolution of the rotary member 8 can be optionally set at least every one of the conditions of the kind of threads, the revolution speed of the main shaft 21 of the loom, and so forth, accurate twist corresponding to such a condition can be formed.
Assuming that the number of revolution of the rotary member 8, when it is turned in reverse, is an integer-double unit of the half revolution, it may be set at n × half revolution. It is needless to say that the minimum number of revolution capable of forming the twists between the selvedge threads 12, 13 is defined as a settable minimum value. In the control shown in Fig. 4, the settable minimum value is one revolution (half revolution + half revolution), and in the control shown in Fig. 5, it is one and a half revolution (one revolution + half revolution), respectively. Since the rotary member 8 of the electric selvedge device 10 is turned normally per half revolution unit, if the number of revolution of the rotary member 8 can be set per half revolution unit, the setting per se can be simplified. For example, buttons of ┌▴┘ ┌▾┘ are provided on the input device 22 for setting the number of revolution of the rotary member 8 when the rotary member 8 is turned in reverse, wherein if one button ┌▴┘ is pushed, the number of revolution, when the rotary member 8 is turned in reverse, increases per half revolution unit, while if the other button ┌▾┘ is pushed, the number of revolution, when the rotary member 8 is turned in reverse, decreases per half revolution unit.
Further, the controller 11 relatively changes the number of revolution of the rotary member 8 and the revolution speed, when the rotary member 8 is turned in reverse, if need be. If the revolution speed is allowed to increase as the number of revolution of the rotary member 8 increases when the rotary member 8 is turned in reverse, time needed for the turning of the rotary member 8, when it is turned in reverse, can be reduced, and also the rotary member 8 can be synchronized with the main shaft 21 of the loom. Meanwhile, it is desirable that the time needed for the rotary member 8 to be turned in one direction or in the other direction is substantially the same as the time needed for the turning of the rotary member 8 to be turned in reverse. It is needless to say that the rotary member 8 can be structured as a propeller type.
According to the invention, since the electric selvedge device turns a rotary member provided with a pair of guide portions, through which selvedge threads pass, in one direction, and turns subsequently in the other direction, thereby forming selvedge, wherein when the rotary member is turned in reverse from one direction to the other direction, the selvedge threads are entangles with each other and a twist, in which the weft is not inserted, is formed between the wefts which are adjacent to each other at selvedge portions, the effect for fastening mutual selvedge threads which are entangled with the weft is improved, thereby preventing the looseness of the weft to greatly contribute to the quality of the fabric.
Since the number of revolution of the rotary member when it is turned in reverses can be optionally set, the state of entanglement of the selvedge threads can be adjusted, and if multiple number of revolution can be optionally set at least every one of the conditions of the kind of threads, the revolution speed of the main shaft of the loom, and so forth, the accurate twist corresponding to the condition can be formed.
If the number of revolution and the revolution speed, when the rotary member is turned in reverse, are relatively changed, a reversing speed increases as the number of revolution increases when the rotary member is turned in reverse, it is possible to cut down time needed for the turning of the rotary member to be turned in reverse and to synchronize the rotary member with the main shaft of the loom.
The features disclosed in the foregoing description, in the claims and/or in the accompanying drawings may, both separately and in any combination thereof, be material for realising the invention in diverse forms thereof.

Claims

A method of controlling an electric selvedge device (10) for turning a rotary member (8) provided with a pair of guide portions (14, 15), through which selvedge threads (12, 13) pass, in one direction, and subsequently turning the rotary member (8) in other direction to form a selvedge, said method comprising the step of forming a twist, in which a weft (7) is not inserted, by a reverse turning operation of the rotary member (8) when the rotary member (8) is turned in reverse from one direction to the other direction.
The method of controlling an electric selvedge device according to Claim 1, wherein the number of revolution of the rotary member (8), when the rotary member (8) is turned in reverse, can be set optionally.
The method of controlling an electric selvedge device according to Claim 1, wherein the number of revolution of the rotary member (8), and a reverse revolution speed thereof, when the rotary member (8) is turned in reverse, are relatively changed.
An electric selvedge device for driving a rotary member (8) provided with a pair of guide portions (14, 15), through which selvedge threads (12, 13) pass, by a driving unit (9), controlling the rotation of the rotary member by a controller (11) to turn the rotary member (8) in one direction, and to turn subsequently in other direction, thereby forming a selvedge:

wherein a twist, in which a weft (7) is not inserted, is formed by a reverse turning operation of the rotary member (8) when the controller (11) controls the rotary member (8) to be turned in reverse from one direction to the other direction.