EP1728907A1

EP1728907A1 - Cloth-fell position adjuster

Info

Publication number: EP1728907A1
Application number: EP06010385A
Authority: EP
Inventors: Yutaka c/o TSUDAKOMA KOGYO K.K. Matsuyama
Original assignee: Tsudakoma Industrial Co Ltd
Current assignee: Tsudakoma Corp
Priority date: 2005-06-02
Filing date: 2006-05-19
Publication date: 2006-12-06
Also published as: CN1873074A; JP2006336157A

Abstract

A cloth-fell position adjuster (10) is included in a loom (1) having at least one of a designated take-up motor (23) for rotating a surface roller (22) and a designated let-off motor (15) for rotating a warp beam (4), the at least one of the motors (15, 23) being provided independently of a main motor (31) driving a main shaft (26) of the loom (1). If the loom (1) has only one of the motors (15, 23), the adjuster (10) drives the motor (15, 23) independently of the main shaft (26) in response to a rotation command signal in a stopped state of the loom (1). If the loom (1) has both motors (15, 23), the adjuster (10) drives at least one of the motors (15, 23) independently of the main shaft (26) in response to the rotation command signal in a stopped state of the loom (1). The adjuster (10) includes a manual operating unit (40) generating the rotation command signal in response to a manual operation, and a drive controller (33) driving the at least one of the motors (15, 23) independently of the main shaft (26) by a rotational amount in response to one time the rotation command signal received from the manual operating unit (40). The rotational amount corresponds to an amount including a value of 1 pick or a pick value having one or more digits to the right of the decimal point.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cloth-fell position adjuster for adjusting the position of the cloth fell in a stopped state of a loom or after a yarn mending process prior to reactivation of the loom.

2. Description of the Related Art

In a stopped state of a loom, if a weft yarn is pulled out from the cloth fell to perform a weft mending process, the position of the cloth fell changes in response to the removed weft yarn. Therefore, it is necessary to adjust the position of the cloth fell before reactivating the loom. Generally, an operator manually rotates a take-up motor or a let-off motor to set the cloth fell back to its original position, which is where the cloth fell was positioned just after the stopping of the loom. If the cloth fell is not properly set back to its original position, a stop mark is formed on the woven cloth.
For example, Japanese Examined Patent Application Publication No. 3-67132 discloses a technique in which a take-up motor and a let-off motor are rotated by an amount corresponding to a shifting distance in units of 1 pick in response to each pressing of a switch so as to shift the cloth fell. In this technique, even if the position of the cloth fell is adjusted after removal of one weft yarn, the actual warp tension, for example, prevents the inserted weft yarns from being properly shifted by the shifting distance in units of 1 pick. For this reason, there are cases where the weft insertion is actually incomplete, and even if the cloth fell is shifted in units of 1 pick, the cloth fell cannot be set back to its proper position. Moreover, if a plurality of weft yarns is removed, the distance error between adjacent picks becomes greater, thus causing more difficulties in setting the cloth fell back to its proper position.
Japanese Examined Utility Model Registration Application Publication No. 1-39727 discloses a technique in which a take-up motor and a let-off motor are rotated while a switch is being pressed so that the position of the cloth fell can be adjusted visually. In this technique, an operator cannot grasp the rotational amounts of the motors during the adjustment process, which means that a proper adjustment for the cloth-fell position is extremely difficult.
Accordingly, the above-referenced cloth-fell position adjustment techniques are disadvantageous in view of preventing stop marks due to difficulties in setting the cloth fell back to its proper position.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to achieve an accurate adjustment of the position of the cloth fell after a weft mending process so as to prevent stop marks from being formed after reactivation of a loom.
The present invention provides a cloth-fell position adjuster included in a loom that has at least one of a designated take-up motor for rotating a surface roller and a designated let-off motor for rotating a warp beam. The at least one of the take-up motor and the let-off motor is provided independently of a main motor that drives a main shaft of the loom. If the loom has only one of the designated motors, the cloth-fell position adjuster drives the one of the designated motors independently of the main shaft in response to a rotation command signal in a stopped state of the loom. If the loom has both designated motors, the cloth-fell position adjuster drives at least one of the designated motors independently of the main shaft in response to the rotation command signal in a stopped state of the loom. The cloth-fell position adjuster is characterized by including a manual operating unit that generates the rotation command signal in response to a manual operation; and a drive controller that drives the at least one of the designated motors independently of the main shaft by a rotational amount in response to one time the rotation command signal received from the manual operating unit, the rotational amount corresponding to an amount including a value of 1 pick or a pick value having one or more digits to the right of the decimal point.
Accordingly, an operator may preliminarily set the rotational amount in units of 1 pick or less, more specifically, in units of picks or millimeters in accordance with, for example, a weft density or a warp-tension value, and operate, for example, a switch in accordance with the number of weft yarns removed for mending the weft yarns or the number of times a pick-finding process is performed. Thus, the motor shifts the cloth fell by a distance corresponding to a rotational amount that corresponds to an amount including a value of 1 pick or a pick value having one or more digits to the right of the decimal point. Consequently, the operator can set the cloth fell back to its proper position, which is where the cloth fell was positioned just before the stopping of the loom. This prevents a stop mark from being formed. Furthermore, since the position of the cloth fell can be finely adjusted on the basis of the rotational amount corresponding to the amount including a value of 1 pick or a pick value having one or more digits to the right of the decimal point, a stop mark can be reduced to the minimum even if the number of times the cloth-fell adjustment process is performed is incorrect. The number of times a pick-finding process is performed refers to the number of times the main shaft is rotated in the reverse direction for exposing a weft yarn in a shed.
Furthermore, the at least one of the designated motors may be the designated let-off motor. In this case, the drive controller may calculate the rotational amount of the let-off motor on the basis of a weft density and a wound diameter of the warp beam around which warp yarns are wound. Alternatively, the at least one of the designated motors may be the designated take-up motor. In that case, the drive controller may calculate the rotational amount of the take-up motor on the basis of a diameter of the surface roller and the weft density.
Accordingly, since the rotational amount may be calculated on the basis of the wound diameter of warp yarns around the warp beam that changes in the course of a weaving operation and the weft density or on the basis of the diameter of the surface roller and the weft density, the adjustment for the position of the cloth fell can be properly performed.
Furthermore, the rotational amount of the at least one of the designated motors rotated in response to one time the rotation command signal may be set individually for each of weft yarns removed for weft mending or for each of pick-finding processes performed in the loom. Alternatively, the rotational amount of the at least one of the designated motors rotated in response to one time the rotation command signal may be set in accordance with a shedding pattern.
Accordingly, the rotational amount of the at least one of the designated motors may be set individually or in a stepwise fashion for each of weft yarns removed for weft mending or for each of pick-finding processes performed in the loom. Actually, the positional error of the cloth fell becomes greater gradually as the number of weft yarns removed for weft mending increases. In detail, the distance between adjacent weft yarns for each weft insertion increases gradually to a distance value that is greater than a value corresponding to 1 pick. Therefore, the rotational amount is set in a stepwise-incremented fashion with respect to the rotational amount for the first adjustment as the number of weft yarns removed or the number of times a pick-finding process is performed in the loom increases. For example, the rotational amounts may be set in the following manner: 1.1 picks for the first adjustment, 1.2 picks for the second adjustment, 1.3 picks for the third adjustment, and so on. Accordingly, this allows the cloth fell to be shifted back to its proper position more accurately.
On the other hand, since the shedding pattern has a great effect on the warp tension, setting the rotational amount in accordance with the shedding pattern allows the position of the cloth fell to be adjusted in a more accurate manner.
Furthermore, the drive controller may automatically set the rotational amount for each of pick-finding processes performed in the loom when the loom is in the stopped state so as to automatically drive the at least one of the designated motors by the set rotational amount. Furthermore, the drive controller may be provided with a display unit that displays a history of the amount corresponding to the rotational amount of the at least one of the designated motors in units of picks or millimeters, the amount obtained every time the rotation command signal is received from the manual operating unit. Specifically, the term "stopped state" refers to a condition where a weaving operation is stopped.
Accordingly, since the position of the cloth fell can be adjusted automatically without requiring a manual operation by the operator, a cloth-fell adjustment process performed by the operator can be simplified, thereby reducing the workload of the operator.
Furthermore, since the display unit may display the history of the amount corresponding to the rotational amount in units of picks or millimeters and obtained every time the rotation command signal is received from the manual operating unit, or more specifically, obtained in response to each manual operation, the operator can readily grasp the number of times the position of the cloth fell is adjusted and the amount corresponding to the rotational amount of each motor for every cloth-fell adjustment process.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 schematically illustrates an overall structure of a loom 1, a loom controller 2, and a cloth-fell position adjuster 10;
Fig. 2 is a flow chart of a cloth-fell adjustment process;
Fig. 3 schematically illustrates a display window of a display unit 35;
Fig. 4 schematically illustrates another display window of the display unit 35;
Fig. 5 schematically illustrates another display window of the display unit 35; and
Fig. 6 schematically illustrates another display window of the display unit 35.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 illustrates a relevant portion of a loom 1, a loom controller 2, and a cloth-fell position adjuster 10 according to the present invention. In Fig. 1, warp yarns 3 fed from a warp beam 4 in a sheet-like manner pass through a tension roller 5 and form a shed 8 in response to a vertical movement of a heald 6. In the shed 8, an inserted weft yarn 7 is interwoven with the warp yarns 3 and is beaten against a cloth fell 11 with a reed 9 so as to form woven cloth 12. The woven cloth 12 is wound around two rollers 21 and a surface roller 22 so as to be finally taken up by a cloth beam 13.
The warp beam 4 is controlled by a let-off controller 14 and a let-off motor 15. Specifically, the let-off controller 14 detects the tension of the sheet of warp yarns 3 at the position of the tension roller 5 via a tension detector 20, detects the wound diameter of the warp yarns 3 around the warp beam 4 (i.e. the diameter of the warp beam 4 around which the warp yarns 3 are wound) via a wound-diameter detector 16, drives the let-off motor 15 via a drive amplifier circuit 17 on the basis of the detected tension information (tension signal) and the detected wound-diameter information (wound-diameter signal), and controls the rotational amount of the let-off motor 15 (i.e. the let-off amount of the warp yarns 3) while checking the rotation of the let-off motor 15 under feedback control via an encoder 18. The rotation of the let-off motor 15 is transmitted to the warp beam 4 through a decelerator 19 having a high reduction ratio. Instead of using the wound-diameter detector 16, for example, the let-off controller 14 may alternatively determine the wound diameter of the warp yarns 3 by obtaining the rotational amount of the let-off motor 15.
The surface roller 22 is driven by a take-up motor 23 and a decelerator 24. The rotation of the take-up motor 23 is controlled by a take-up controller 25. The take-up controller 25 drives the take-up motor 23 via a drive amplifier circuit 27 in synchronization with rotation of a main shaft 26 of the loom 1, and controls the rotational amount of the take-up motor 23 (i.e. the take-up amount of the woven cloth 12) while checking the rotation of the take-up motor 23 under feedback control via an encoder 28. Although not shown, the cloth beam 13 is driven by a commonly known device. Accordingly, the let-off motor 15 and the take-up motor 23 are provided and driven independently of a main motor 31 that drives the main shaft 26.
The heald 6 is driven by a shedding mechanism 29. The shedding mechanism 29 is controlled by a shed controller 30 in synchronization with the rotation of the main shaft 26. The main shaft 26 is driven by the main motor 31, and the rotation of the main shaft 26 is detected by an encoder 38. The detected rotation signal is sent to the take-up controller 25 and the shed controller 30.
The loom controller 2 includes the let-off controller 14, the take-up controller 25, the shed controller 30, a memory unit 32, and a drive controller 33. The memory unit 32 stores rotational-amount data received from a setting unit 34. The drive controller 33 includes an arithmetic unit 36 that calculates a let-off amount of the warp yarns 3 and a take-up amount of the woven cloth 12 for shifting the cloth fell 11, and a command unit 37 that sends a let-off rotation command signal to the let-off motor 15 and a take-up rotation command signal to the take-up motor 23. Furthermore, a display unit 35 is provided for displaying, for example, weaving condition data, let-off amount data, and take-up amount data where necessary.
The cloth-fell position adjuster 10 contains the memory unit 32 and the drive controller 33, which are included in the loom controller 2, and also contains the setting unit 34, the display unit 35, and a manual operating unit 40. The manual operating unit 40 includes five switches that are manually operated to generate rotation command signals when the loom 1 is in a stopped state. The five switches are a start switch 41, a cloth-fell-adjustment forward switch 42, a cloth-fell-adjustment reverse switch 43, a loom forward-drive switch 44, and a loom reverse-drive switch 45.
The start switch 41 is pressed to start the operation of the loom 1. The loom forward-drive switch 44 is used when performing gaiting for winding the sheet of warp yarns 3 around the surface roller 22 and the cloth beam 13 during a looming process. In gaiting, a weft-insertion process is performed manually for several picks. The loom reverse-drive switch 45 is used when mending the weft yarns 7. In detail, every time the loom reverse-drive switch 45 is pressed, the main shaft 26 of the loom 1 is reversed by a predetermined amount. In this embodiment, the main shaft 26 is reversed by one rotation in response to each pressing of the loom reverse-drive switch 45, and the number of times the loom reverse-drive switch 45 is pressed will be referred to as a pick-finding number indicating the number of times a pick-finding process is performed.
Every time the cloth-fell-adjustment forward switch 42 is pressed, at least one of the let-off motor 15 and the take-up motor 23 is rotated by a after-mentioned predetermined amount so that the cloth fell 11 is shifted towards the take-up side by a predetermined distance. On the other hand, every time the cloth-fell-adjustment reverse switch 43 is pressed, at least one of the let-off motor 15 and the take-up motor 23 is rotated in the reverse direction by a after-mentioned predetermined amount so that the cloth fell 11 is shifted towards the let-off side by a predetermined distance. The cloth-fell-adjustment forward switch 42 and the cloth-fell-adjustment reverse switch 43 may alternatively be defined by a common single cloth-fell adjustment switch used for shifting the cloth fell 11 in one of the directions.
Data for shifting the cloth fell 11 is set in the setting unit 34 individually as a let-off amount indicating a rotational amount of the let-off motor 15 and as a take-up amount indicating a rotational amount of the take-up motor 23. For shifting the cloth fell 11, only one of the let-off motor 15 and the take-up motor 23 may be rotated, or both the let-off motor 15 and the take-up motor 23 may be rotated simultaneously.
The setting unit 34 has a numerical input portion, such as a numeric keypad, and contains an arithmetic portion or a program that receives a numerical signal from the numeric keypad and that outputs the numerical information to the memory unit 32. An operator may operate the numerical input portion of the setting unit 34 to preliminarily input a let-off amount, a take-up amount, and other weaving conditions, such as a weft density, and a shedding pattern. In response to the input by the operator, the arithmetic portion or the program in the setting unit 34 determines parameters for the let-off amount, the take-up amount, and other weaving conditions, and stores the determined parameters in the memory unit 32. The let-off amount and the take-up amount are in units of picks or millimeters.
When the operator presses the start switch 41, a start command signal is sent to the loom controller 2. The loom controller 2 actuates the main motor 31 and activates the let-off controller 14, the take-up controller 25, and the shed controller 30 in accordance with the set weaving conditions so as to start a weaving operation. As mentioned above, the let-off controller 14 performs feedback control on the let-off motor 15, and the take-up controller 25 performs feedback control on the take-up motor 23. The shed controller 30 outputs a shedding command signal to the shedding mechanism 29 in accordance with the set shedding pattern in order to drive the heald 6. During the weaving operation, all the switches in the manual operating unit 40 are locked so that these switches do not respond even if they are pressed accidentally.

First Embodiment

A first embodiment of the present invention is directed to an example in which rotational amounts corresponding to 1 pick or less are set in an adjustable fashion. In the other words, a rotational amount that is smaller than the rotational amount of each designated motor 15, 23 corresponding to the distance between adjacent weft yarns 7 is set in an adjustable fashion. Here, the let-off amount and the take-up amount are both set to 0.7 picks. In this case, the rotational amounts of the let-off motor 15 and the take-up motor 23 equivalent to a shifting distance for shifting the cloth fell 11 are both set to 0.7 picks. If the let-off amount or the take-up amount is set to zero, it means that the let-off motor 15 or the take-up motor 23 does not rotate.
Fig. 2 is a flow chart of a cloth-fell adjustment process performed when the loom 1 is in a stopped state. This flow chart of the cloth-fell adjustment process may be applied when the loom 1 is shutdown due to, for example, weft-insertion errors and warp errors. If a weft-insertion error occurs, the loom 1 is stopped and the defective weft yarn 7 is pulled out for mending. This causes the cloth fell 11 to be shifted forward from its proper position. Therefore, the operator presses the cloth-fell-adjustment reverse switch 43 functioning as a cloth-fell adjustment switch. In contrast, when repairing a broken warp yarn in a case where a warp error occurs, the cloth fell 11 is shifted backward from its proper position due to, for example, manual weft insertion. Therefore, the operator presses the cloth-fell-adjustment forward switch 42 also functioning as a cloth-fell adjustment switch.
The description below will be based on the assumption that the cloth fell 11 is shifted forward as a result of a weft-insertion error. Therefore, the cloth-fell adjustment switch in Fig. 2 corresponds to the cloth-fell-adjustment reverse switch 43. Needless to say, if the cloth fell 11 is shifted backward as a result of a warp error, the cloth-fell adjustment switch will automatically correspond to the cloth-fell-adjustment forward switch 42.
The cloth-fell adjustment process in Fig. 2 can be started in the course of a weaving operation of the loom 1. If the loom 1 is stopped due to, for example, a weft-insertion error during a weaving operation, the process advances to step 1.
In step 1, the setting unit 34 displays a "STOP" sign as shown in the upper right section of Fig. 4, which indicates the stopped condition of the loom 1. To mend the inserted weft yarns 7, if the operator removes, for example, three weft yarns 7 from the cloth fell 11, the operator has to remember the number of removed weft yarns 7, which in this case is three. Since this causes the cloth fell 11 to be shifted forward from its original position, the operator first presses the cloth-fell-adjustment reverse switch 43 once.
In step 2, it is determined whether the cloth-fell adjustment switch is pressed. If it is determined to be "Y" (yes), meaning the cloth-fell-adjustment reverse switch 43 is pressed, the process advances to step 3. On the other hand, if it is determined to be "N" (no) in step 2, the process advances to step 6 where it is determined whether the let-off motor 15 and the take-up motor 23 are rotating. If it is determined to be "N" in step 6, the process returns to step 2. If it is determined to be "Y" in step 6, the process advances to step 7.
In step 3, the arithmetic unit 36 calculates a rotational amount of the let-off motor 15 corresponding to a let-off amount on the basis of a detection value of the current wound diameter of the sheet of warp yarns 3 and a setting value of a weft density, and also calculates a rotational amount of the take-up motor 23 corresponding to a take-up amount on the basis of the diameter of the surface roller 22 and the setting value of the weft density. The wound diameter of the warp yarns 3 around the warp beam 4 decreases in the course of the weaving operation, but the diameter of the surface roller 22 does not change.
In step 4, the command unit 37 sends a rotation command signal to the let-off controller 14 based on the calculated let-off rotational amount, and also sends a rotation command signal to the take-up controller 25 based on the calculated take-up rotational amount. Thus, the let-off motor 15 and the take-up motor 23 are rotated by the designated rotational amounts.
In step 5, the display unit 35 displays an "IN OPERATION" sign as shown in the upper right section of Fig. 3, which indicates that the let-off motor 15 and the take-up motor 23 are rotating.
When the rotation of each of the let-off motor 15 and the take-up motor 23 is completed, it is determined to be "Y" in step 7. Subsequently, in step 8, the display unit 35 displays the "STOP" sign as shown in the upper right section of Fig. 4. In step 9, the display unit 35 displays a history of the let-off and take-up amounts in units of picks corresponding to the rotational amounts. Specifically, an indication that reads "1ST: LET-OFF 0.7 TAKE-UP 0.7" picks corresponding to the rotational amounts of the let-off motor 15 and the take-up motor 23 is displayed together with total values. This completes the process performed in response to the first pressing of the cloth-fell-adjustment reverse switch 43.
Similar to the above, the operator may press the cloth-fell-adjustment reverse switch 43 for the number of removed weft yarns 7 so as to repeat the above steps. Every time the cloth-fell-adjustment reverse switch 43 is pressed, the display unit 35 displays the history of the let-off and take-up amounts corresponding to the rotational amounts of the let-off motor 15 and the take-up motor 23 as shown in Fig. 5. Moreover, the display unit 35 also displays the total values of the let-off and take-up amounts corresponding to the rotational amounts from the point at which the loom 1 was stopped. Alternatively, the display unit 35 may display only the total values of the let-off and take-up amounts corresponding to the rotational amounts of the let-off motor 15 and the take-up motor 23.
After one pressing of the cloth-fell adjustment switch (cloth-fell-adjustment forward switch 42 or cloth-fell-adjustment reverse switch 43), if the cloth-fell adjustment switch (cloth-fell-adjustment forward switch 42 or cloth-fell-adjustment reverse switch 43) is pressed again in the course of the rotation of the let-off motor 15 and the take-up motor 23, the command unit 37 successively sends rotation command signals to the let-off controller 14 and the take-up controller 25. The command signals are then sent to the motors (let-off motor 15 and take-up motor 23). Consequently, the motors (let-off motor 15 and take-up motor 23) continue to rotate while the rotational amounts thereof are increased every time the cloth-fell adjustment switch is pressed.
Alternatively, the rotational amounts corresponding to the let-off and take-up amounts may include pick values having one or more digits to the right of the decimal point. For example, the rotational amounts may be set in units of 0.1 picks, such as 0.8 picks and 1.1 picks, or in units of 0.01 picks, such as 0.65 picks. As a further alternative, if the rotational amounts are 1 pick or less, the rotational amounts may be set to fixed values by the manufacturer. If the rotational amounts are set to fixed values, the fixed values are preferably set to one n-th of 1 pick, such as 0.25 picks and 0.5 picks, n being a positive integer. Furthermore, if fixed values are set, the rotational amounts are stored in the memory unit 32, and therefore, the setting unit 34 is not necessary. The fixed values are preferably set within a close range of 1 pick, such as 0.8 picks and 1.1 picks.
When mending the weft yarns 7, the reed 9 is withdrawn by reversing the main shaft 26 of the loom 1 in response to pressing of the loom reverse-drive switch 45 so that a defective weft yarn 7 can be readily removed. In this case, the operator may press the cloth-fell-adjustment reverse switch 43 functioning as the cloth-fell adjustment switch on the basis of the number of times the loom reverse-drive switch 45 is pressed for weft mending instead of the number of removed weft yarns 7. For example, if the loom reverse-drive switch 45 is pressed three times for removing three weft yarns, or in other words, if a pick-finding process is performed three times, the cloth-fell-adjustment reverse switch 43 may be pressed three times after the weft mending process. Depending on the loom 1, there may be a case where the loom reverse-drive switch 45 is pressed a plurality of times for one weft yarn 7 in order to reverse the main shaft 26 by one rotation. In that case, the operator has to remember the number of times the main shaft 26 is rotated in the reverse direction in response to the pressing of the loom reverse-drive switch 45 so that the operator can press the cloth-fell-adjustment reverse switch 43 for the number of times the main shaft 26 reached one rotation.
The technical scope of the present invention includes a case where the let-off amount and the take-up amount are set in units of millimeters in the setting unit 34. For example, if a length corresponding to 1 pick is 2 mm and the let-off and take-up amounts are set to 0.5 mm, 1 mm, 3 mm and so on, the pick values corresponding to these values will be 0.25 picks, 0.5 picks, 1.5 picks and so on. Therefore, these values correspond to amounts including pick values having one or more digits to the right of the decimal point.
Furthermore, the cloth-fell adjustment switch (cloth-fell-adjustment forward switch 42, cloth-fell-adjustment reverse switch 43) may be locked when the motors (15, 23) are rotating. For example, the display unit 35 displays the "IN OPERATION" sign as shown in the upper right section of Fig. 3 when the motors (15, 23) are rotating, and from this point, the cloth-fell adjustment switch (42, 43) may be locked. When the rotation of the motors (15, 23) is completed and the display unit 35 displays the "STOP" sign as shown in the upper right section in Fig. 4, the cloth-fell adjustment switch (42, 43) may be unlocked so as to accept cloth-fell adjustment.

Second Embodiment

A second embodiment of the present invention is directed to an example in which the rotational amounts for the second adjustment onward are set automatically to amounts equivalent to the actual distance between adjacent weft yarns on the basis of the rotational amounts for the first adjustment. The rotational amounts may be set individually for each of removed weft yarns 7 at the time of weft mending or for each pick-finding process performed in the loom 1. For example, the rotational amounts applied at the time of the first removed weft yarn 7 may be set separately from the rotational amounts applied at the time of the second removed weft yarn 7, or the rotational amounts applied at the time of first pick-finding may be set separately from the rotational amounts applied at the time of second pick-finding. In detail, the rotational amounts may increase in a stepwise fashion. For example, if the rotational amounts for the first adjustment are set to 0.7 picks, the rotational amounts for the second adjustment are set to 0.7 picks x 1.1, and the rotational amounts for the third adjustment are set to 0.7 picks x 1.2. In other words, when the rotational amounts for the first adjustment are set, the rotational amounts for the second adjustment onward are set automatically in a stepwise-incremented fashion. Alternatively, the rotational amounts may be incremented by a predetermined pick value for every adjustment. For example, if the rotational amounts for the first adjustment are set to 0.7 picks, the rotational amounts for the second adjustment may be set to 0.8 picks, and the rotational amounts for the third adjustment may be set to 0.9 picks.
Fig. 6 illustrates history data of let-off and take-up amounts incremented by the predetermined pick value (0.1 pick) for every adjustment. The let-off and take-up amounts corresponding to the rotational amounts may be input manually by the operator.
The rotational amounts for each round of the adjustments corresponding to the number of removed weft yarns 7 or the pick-finding number in the loom 1 may be preliminarily set so that the rotational amounts for the plurality of adjustments are used at once in response to one pressing of the cloth-fell-adjustment reverse switch 43. For example, the let-off and take-up amounts corresponding to the rotational amounts may be preliminarily set for three removed weft yarns 7 so that when the operator pulls out three weft yarns 7 and then presses the cloth-fell-adjustment reverse switch 43 once, the cloth fell 11 is adjusted by a distance corresponding to the three removed weft yarns 7.

Third Embodiment

A third embodiment of the present invention is directed to an example in which the rotational amounts are set automatically or manually in accordance with a shedding pattern. For example, in a shedding pattern, if the top dead center and the bottom dead center alternate continuously in the heald 6 for every pick, the tension of the warp yarns 3 tends to increase. Therefore, the set rotational amounts are increased by a predetermined rate on the basis of, for example, the number of times the top dead center and the bottom dead center alternate in the shedding pattern. In this case, the term "shedding pattern" refers to a shedding pattern for cloth-fell adjustment.

Fourth Embodiment

A fourth embodiment of the present invention is directed to an example in which the drive controller 33 automatically calculates appropriate rotational amounts for rotating the motors (15, 23). The drive controller 33 stores the number of times the loom reverse-drive switch 45 is pressed in the stopped state of the loom 1 (i.e. for weft mending) and calculates rotational amounts for rotating the motors (15, 23) on the basis of the pressed number and the set rotational amounts corresponding to each pressing of the cloth-fell adjustment switch so as to automatically set the rotational amounts. Thus, the motors (15, 23) are automatically rotated before the loom 1 is reactivated. Alternatively, the number of times the loom reverse-drive switch 45 is pressed may be stored in the memory unit 32 so that the drive controller 33 can read out the pressed number of the loom reverse-drive switch 45 from the memory unit 32.
In a case where the loom 1 is a type in which the loom reverse-drive switch 45 is pressed a plurality of times for one weft yarn 7 to reverse the main shaft 26 by one rotation, the memory unit 32 stores the number of times the main shaft 26 is rotated in the reverse direction in response to the pressing of the loom reverse-drive switch 45 so that the number of rotations is set automatically in accordance with the number of times the main shaft 26 reached one rotation. Alternatively, the number of rotations of the main shaft 26 may be calculated from the number of times the loom reverse-drive switch 45 is pressed.
The present invention may be applied to both the let-off motor 15 and the take-up motor 23 or to one of the let-off motor 15 and the take-up motor 23. Furthermore, as is apparent from the above description, the cloth-fell adjustment switch corresponds to the cloth-fell-adjustment reverse switch 43 or the cloth-fell-adjustment forward switch 42. Specifically, if the cloth fell 11 is shifted forward in the stopped state of the loom 1, the cloth-fell-adjustment reverse switch 43 is pressed so that the cloth fell 11 is shifted back to its proper position before reactivation. On the other hand, if the cloth fell 11 is shifted backward in the stopped state of the loom 1, the cloth-fell-adjustment forward switch 42 is pressed so that the cloth fell 11 is shifted back to its proper position before reactivation.
Furthermore, the present invention is also applicable to a loom that drives the surface roller 22 with the main motor 31 that drives the main shaft 26 instead of using the designated take-up motor 23. In that case, the cloth-fell adjustment process is performed by driving the let-off motor 15.

Claims

A cloth-fell position adjuster (10) is included in a loom (1) having at least one of a designated take-up motor (23) for rotating a surface roller (22) and a designated let-off motor (15) for rotating a warp beam (4), wherein the at least one of the take-up motor (23) and the let-off motor (15) is provided independently of a main motor (31) that drives a main shaft (26) of the loom (1), wherein if the loom (1) has only one of the designated motors (15, 23), the cloth-fell position adjuster (10) drives the one of the designated motors (15, 23) independently of the main shaft (26) in response to a rotation command signal in a stopped state of the loom (1), and wherein if the loom (1) has both designated motors (15, 23), the cloth-fell position adjuster (10) drives at least one of the designated motors (15, 23) independently of the main shaft (26) in response to the rotation command signal in a stopped state of the loom (1), the cloth-fell position adjuster (10) comprising:
a manual operating unit (40) that generates the rotation command signal in response to a manual operation; and

a drive controller (33) that drives the at least one of the designated motors (15, 23) independently of the main shaft (26) by a rotational amount in response to one time the rotation command signal received from the manual operating unit (40), the rotational amount corresponding to an amount including a value of 1 pick or a pick value having one or more digits to the right of the decimal point.
The cloth-fell position adjuster (10) according to Claim 1, wherein the at least one of the designated motors (15, 23) comprises the designated let-off motor (15), and
wherein the drive controller (33) calculates the rotational amount of the let-off motor (15) on the basis of a weft density and a wound diameter of the warp beam (4) around which warp yarns (3) are wound.
The cloth-fell position adjuster (10) according to any one of Claim 1 to 2, wherein the at least one of the designated motors (15, 23) comprises the designated take-up motor (23), and
wherein the drive controller (33) calculates the rotational amount of the take-up motor (23) on the basis of a diameter of the surface roller (22) and a weft density.
The cloth-fell position adjuster (10) according to any one of Claims 1 to 3, wherein the rotational amount of the at least one of the designated motors (15, 23) rotated in response to one time the rotation command signal is set individually for each of weft yarns (7) removed for weft mending or for each of pick-finding processes performed in the loom (1).
The cloth-fell position adjuster (10) according to any one of Claims 1 to 3, wherein the rotational amount of the at least one of the designated motors (15, 23) rotated in response to one time the rotation command signal is set in accordance with a shedding pattern.
The cloth-fell position adjuster (10) according to any one of Claims 1 to 3, wherein the drive controller (33) automatically sets the rotational amount for each of pick-finding processes performed in the loom (1) when the loom (1) is in the stopped state, and automatically drives the at least one of the designated motors (15, 23) by the set rotational amount.
The cloth-fell position adjuster (10) according to any one of Claims 1 to 6, wherein the drive controller (33) is provided with a display unit (35) that displays a history of the amount corresponding to the rotational amount of the at least one of the designated motors (15, 23) in units of picks or millimeters, the amount obtained every time the rotation command signal is received from the manual operating unit (40).