EP1987182B1

EP1987182B1 - Method for driving heddle frames and weaving machine

Info

Publication number: EP1987182B1
Application number: EP07711591A
Authority: EP
Inventors: Dirk Sampers; Koenraad Vandecasteele; Piet Verdiere
Original assignee: Picanol NV
Current assignee: Picanol NV
Priority date: 2006-02-20
Filing date: 2007-02-20
Publication date: 2011-05-18
Anticipated expiration: 2027-02-20
Also published as: WO2007096129A1; CN101389795B; ATE510052T1; EP1987182A1; CN101389795A; BE1017000A3

Abstract

A method for driving a cam system (3) for driving heddle frames (1, 2) in a weaving machine, wherein, during a displacement (69, 79) of the central bearing shaft (6) of the cam system (3), the cams (19, 20) of the cam system (3) are positioned in an intermediate angular position (54, 56), so that the heddle frames (1, 2), during a displacement (69, 79) of the central bearing shaft (6), move virtually between an upper limit (40) and a lower limit (38) of their motional course (41). A weaving machine for the application of such a method.

Description

The invention relates to a method for driving heddle frames in a weaving machine containing a cam system for driving heddle frames. The invention also relates to a weaving machine for the application of such a method.
Such a cam system for heddle frames, which allows heddle frames to be driven, more particularly heddle frames to be leveled and deleveled again, is known, inter alia, from US 2654397 . Following the stoppage of a weaving machine as a consequence of a warp break, a weft fault or some other fault, the heddle frames with associated warp threads can be leveled within a plane to enable a weaver easily to locate and/or repair a break or a fault. In addition, leveling can also be carried out during a change of article or during some other intervention on a weaving machine. In the case of a warp break, a weaver can easily determine after the leveling the location of a broken warp thread. In the case of a weft fault, a pick-finding procedure can be conducted after the leveling in order to free the faulty weft thread and remove it. Following the leveling, a deleveling can take place.
In known cam systems, a central bearing shaft of the cam followers is relatively heavily loaded during the weaving and in consequence suffers vibrations. An embodiment as known from US 2654397 is hence subject to wear, such wear resulting in the creation of an inadmissible play between the component parts supporting the central bearing shaft of the cam followers. An embodiment as known from EP 580.528 A1 can offer a solution for this, which solution consists in the ends of the central bearing shaft of the cam followers pressing elastically during the weaving against fixed stop points of the frame of the cam system. However, this still gives rise to a bulky structure with a large number of component parts, which are each individually prone to wear.
Other embodiments are known from FR 2317395 and WO 2005/098107 . In such a cam system, the central bearing shaft of the cam followers is arranged eccentrically in the frame of the cam system. This structure, which is fastened directly to the frame of the cam system, offers good mechanical stability during the weaving. However, the route taken by the central bearing shaft of the cam followers during the leveling and the deleveling runs virtually in a circular arc, i.e. not in a straight line and not transversely to the central bearing shaft of the cams as known in the embodiments of US 2654397 and EP 580.528 A1 . Hence, set cam followers are forced to first undergo during the leveling procedure a displacement in the direction of opening of a shed. In some cases, such as, for example, in the deleveling following the execution of a pick-finding procedure to expose a faulty weft thread, set heddle frames, during the leveling or the deleveling of the heddle frames, assume a position which is situated outside their normal motional course. This has the drawback that the warp threads are heavily loaded during the leveling or the deleveling. This latter can lead to breakage of these warp threads, to a permanent elongation of these warp threads, or to a so-called starting stripe or weave stripe in the weave when the weaving process is restarted.
One object of the invention is a method for leveling or deleveling heddle frames, which method does not display the aforementioned drawbacks.
To this end, a method according to the invention comprises a method in which, during a displacement of the central bearing shaft of the cam system, the cams of the cam system are positioned in an intermediate angular position, so that the heddle frames, during a displacement of the central bearing shaft, move virtually between an upper limit and a lower limit of their motional course.
A method according to the invention offers the advantage that, during the leveling and the subsequent deleveling, the warp threads are virtually no more heavily loaded than during the normal weaving, whereby the heddle frames can be leveled and deleveled without any drawbacks. Moreover, the leveling and deleveling structure which is fastened to the frame of the cam system offers good mechanical stability during the weaving. The method offers the advantage that the heddle frames are able to move, within their motional course for the weaving, both during the leveling and during the deleveling.
According to one embodiment, the method is applied during the leveling of heddle frames. According to one embodiment, before a displacement of the central bearing shaft of the cam system takes place, the cams of the cam system are positioned by means of a determinant algorithm from a set angular position into an intermediate angular position. According to one embodiment, after a displacement of the central bearing shaft of the cam system has taken place, the cams of the cam system are positioned by means of a determinant algorithm from an intermediate angular position into a set angular position. A set angular position of this type can be chosen, inter alia, for a so-called pick-finding, for a deleveling or for slow motion.
According to one embodiment, the method is applied during the deleveling of heddle frames. According to one embodiment, after a displacement of the central bearing shaft of the cam system has taken place, the cams of the cam system are positioned by means of a determinant algorithm from an intermediate angular position into a set angular position. A set angular position of this type can be chosen, inter alia, for forming a partially open shed or for starting the weaving machine. According to one embodiment, before a displacement of the central bearing shaft of the cam system takes place, the cams of the cam system are positioned by means of a determinant algorithm from a set angular position into an intermediate angular position. This allows, inter alia, the cam system to be positioned in a desired weaving cycle.
Further embodiments of a method according to the invention are explained in greater detail below with reference to illustrative embodiments.
To this end, an invention also comprises a weaving machine comprising a cam system in which the cam system preferably comprises a control lever with cam followers which is mounted on an eccentrically arranged bearing shaft, which bearing shaft is preferably rotatable by an adjusting unit, and the weaving machine also comprises a control unit for controlling the cam system according to the invention.
Further embodiments of a weaving machine according to the invention are explained in greater detail below with reference to illustrative embodiments and subclaims.
In order to present the further advantages of the invention more clearly, the invention, to this end, is explained more closely with reference to drawings containing illustrative embodiments, wherein:

figure 1 represents a portion of a weaving machine having a cam system according to the invention;
figures 2 to 8 represent the cam system according to figure 1 in various positions during the execution of a known method for leveling or deleveling the bottommost warp thread plane, from an open shed;
figure 9 represents a path of successive positions of a heddle frame as represented in figures 2 to 8;
figures 10 to 16 represent the cam system according to figure 1 in various positions during the execution of a known method for leveling or deleveling the topmost warp thread plane, from an open shed;
figure 17 represents a path of successive positions of a heddle frame as represented in figures 10 to 16;
figures 18 to 24 represent the cam system according to figure 1 in various positions during the execution of a known method for leveling or deleveling a warp thread plane, from a closed shed or crossing;
figure 25 represents a path of successive positions of a heddle frame as represented in figures 18 to 24;
figures 26 to 28 represent the cam system according to figure 1 in various positions during the weaving;
figure 29 represents a path of successive positions of a heddle frame as represented in figures 26 to 28;
figures 30 to 36 represent the cam system according to figure 1 in various positions during the execution of a method according to the invention for leveling the bottommost warp thread plane, from an open shed;
figure 37 shows a path of successive positions of a heddle frame as represented in figures 30 to 36;
figure 38 shows a flow chart for illustrating a leveling or deleveling method according to the invention;
figures 39 to 45 represent the cam system according to figure 1 in various positions during the execution of a method according to the invention for deleveling the bottommost warp thread plane, toward an open shed;
figure 46 represents a path of successive positions of a heddle frame as represented in figures 39 to 45;
figure 47 represents a path analogous to figure 46 followed by a motional path analogous to figure 29.

The weaving machine represented in figure 1 comprises a number of heddle frames 1, 2, which can be driven up and down by means of a cam system 3. The cam system 3 comprises control levers 4, 5, which are mounted rotatably about a bearing shaft 6. Each control lever 4 is connectable via a connecting point 7 to a drive rod 8, which is connectable via a second connecting point 9 to a lever 11 mounted about a rotary shaft 10. The lever 11 is connectable via a connecting rod 12 to a second lever 14 mounted about a rotary shaft 13. Each heddle frame 1, 2 is connected via connecting rods 15, 16 to an associated lever 11, 14. The rotary shafts 10 and 13 are mounted in the frame of the weaving machine. The heddle frames 1, 2 are guided in lateral guides 17, 18, fitted to the frame of the weaving machine. The cam system 3 is fixedly disposed relative to the frame of the weaving machine.
The cam system 3 further comprises a pair of cams 19, 20 for driving the heddle frame 1, which respectively cooperate with a cam follower 21, 22. The cam followers 21, 22 are mounted on a control lever 4 for the heddle frame 1. The cams 19, 20 and the cam followers 21, 22 here form a so-called conjugated cam pair. The cam system 3 further comprises for the driving of the heddle frame 2 a pair of cams and associated cam followers, which are provided on the control lever 5. The cams 19, 20 for each heddle frame are fastened on a drive shaft 23, which is driven, for example, by a drive unit 24. The drive unit 24 comprises, for example, a controllable drive motor 25 and a transmission 26. The transmission 26 comprises, for example, a gearwheel 26A provided on the motor shaft of the drive motor 25, an intermediate gearwheel 26B and a gearwheel 26C provided on the drive shaft 23. The cam system 3 is here driven via the transmission 26 by the drive motor 25. Via the control levers 4, 5, the levers 11, 14, the drive rods 8 and the connecting rods 12, 15, 16, the cam system 3 drives the heddle frames 1, 2. In this case, the cam system 3 drives the heddle frames 1, 2 up and down according to a set motional path.
Each heddle frame 1, 2 respectively comprises thread guides 31 and 32, for example healds for guiding warp threads in a known manner. During the weaving, each heddle frame 1, 2 moves up and down in a vertical plane respectively between an upper limit 38 and a lower limit 40. Hence, during the weaving, the warp threads likewise move between an upper limit and a lower limit. The distance or course between the upper limit 38 and the lower limit 40 between which the heddle frames 1, 2 move during the weaving is also referred to as the motional course 41 of the heddle frame 1, 2. Such a motional course 41 is indicated in figure 1. In figure 29, a motional path of a heddle frame for the guidance of a plane of warp threads is represented in the case of a so-called 1/1 binding, that is to say that each plane of warp threads is guided by one of two heddle frames 1, 2, which move alternately. Each heddle frame 1, 2 with a plane of warp threads here moves between an associated upper limit 38 and an associated lower limit 40. Figure 1 shows the cam system 3, the control levers 4, 5, the levers 11, 14, the drive rods 8, the connecting rods 12, 15, 16 and the heddle frames 1, 2 in a state in which the heddle frame 1 is virtually at the lower limit 40 and wherein the heddle frame 2 is virtually at the upper limit 38. The heddle frames 1 and 2 are here shown in a so-called open shed, in other words the warp threads of the plane commanded by the heddle frame 1 and the warp threads of the plane commanded by the heddle frame 2 are at a maximum distance apart. In this position, a weft thread can be brought into a shed or a wrongly inserted weft thread can be removed from the shed. As represented in figure 29, the heddle frames 1 and 2 subsequently respectively follow a motional path 48 and 49, the heddle frame 1 being moved toward an upper limit 38 and, at the same time, the heddle frame 2 being moved toward a lower limit 40. Somewhere between an upper limit 38 and a lower limit 40 a crossover position 39 is reached, at which the warp threads of the two heddle frames 1 and 2 cross. Next, the heddle frame 1 is moved back toward an upper limit 38 and the heddle frame 2 toward a lower limit 40, the warp threads likewise reaching a crossover position 39. In a crossover position 39, the warp threads of both heddle frames 1, 2 are virtually in one and the same plane. During the weaving, the weft threads, for example, are beaten up against the weave whenever the warp threads are virtually in the crossover position 39.
The bearing shaft 6 on which the control levers 4, 5 with the cam followers 21, 22 are fitted is eccentrically arranged via shaft ends 27 fitted rotatably in the frame of the cam system 3. The drive shaft 23 is also rotatably mounted in the frame of the cam system 3. The shaft ends 27 and the bearing shaft 6 are arranged eccentrically to each other and eccentrically to the cam system 3 in such a way that, in a set state of the shaft ends 27, the bearing shaft 6 is positioned such that the cam followers 21, 22 can cooperate with the cams 19, 20 and, in another state of the shaft ends 27, the bearing shaft 6 is positioned such that the cam followers 21, 22 can no longer cooperate with at least one of the cams 19, 20, or even can no longer cooperate with either of the cams 19, 20.
In addition, the cam system 3 comprises an adjusting unit 28 for the rotation of the shaft ends 27. As a result of this rotation, the bearing shaft 6 arranged eccentrically with respect to the shaft ends 27 shall move parallel with itself, as illustrated, for example, in figures 30 to 36. As a result of this displacement, the cam followers 21, 22 can be brought away from the cams 19, 20. The cam followers 21, 22 provided on a control lever 4 can be displaced to the point where the control lever 4, under the influence of the warp tension and/or the weight of the heddle frames 1, 2 and the weight of the component parts connected to the heddle frames 1, 2, hits against at least one stop 29 and a position is reached as represented in figure 35 or 36. Such a stop 29 is fitted such that, should the control lever 4 hit against the stop 29, the associated heddle frame 1 finds itself, for example, in a leveled position, for example in a position somewhere midway between the extreme positions of the heddle frame 1. In the illustrative embodiment as represented in figures 30 to 36, the at least one stop 29 has been arranged such that the leveled position as represented in figure 35 or 36 virtually corresponds with the crossover position 39 at which the heddle frames 1, 2 cross. It is clear that a different position of the at least one stop 29 can lead to a different associated leveled position. It is likewise clear that the position of the at least one stop 29 can also be controllably adjustable. Analogously, at least one stop can be provided for the control lever 5, which is fitted, for example, such that the heddle frames 1, 2 are located virtually in one and the same leveled position according to height or virtually in the crossover position.
The adjusting unit 28 comprises a transmission 34, which allows the shaft end 27 to rotate by means of the drive motor 33. In the represented example, the transmission 34 comprises an intermediate gearwheel 30, which can cooperate with a gearwheel 30A provided on the drive shaft of the drive motor 33 and with a gearwheel 30B rotatable with the shaft end 27. The drive shaft of the drive motor 33, the intermediate gearwheel 30 and the shaft end 27 are rotatably fastened to the frame of the cam system 3. Through the rotation of the drive motor 33, the shaft end 27 is rotated via the transmission 34 and the bearing shaft 6 of the cam followers 4, 5, fastened eccentrically on the shaft end 27, is displaced virtually circularly.
It is also possible, of course, to connect the control levers 4, 5 differently to the heddle frames 1, 2 or to drive the shaft ends 27 differently by a drive motor. This can be done, for example, in a manner as described in WO 2005/098107 , in which the adjusting unit comprises an arm which is fastened on a shaft end and which, at an extreme end, comprises a screw element provided with an internal screw thread. In addition, the adjusting unit here comprises a screw rod provided with an external screw thread which can cooperate with the screw element. The screw rod can be rotatably driven with a drive motor. Rotation of the screw rod in the screw element allows the shaft end to be rotated and an eccentrically arranged bearing shaft of the cam followers to be displaced along a virtually circular path. The drive motor is here fastened via a rotary shaft to the frame of the cam system. According to another variant embodiment, the control levers 4, 5 can be connected to the heddle frames 1, 2 in a manner as described in EP 520540 A1 , WO 2004/081270 or in yet another known manner. According to a non-represented variant, the drive motor 33 and the transmission 34 of the adjusting unit 28 for the rotation of the shaft end 27 can be replaced, for example, by a pneumatic or hydraulic cylinder, an associated plunger shaft and a bearing. According to a non-represented variant, between the drive motor 33 and the shaft end 27 other transmission means can likewise be provided, which can convert a rotary motion of a motor shaft of the drive motor 33 into a rotary motion of the shaft end 27.
The weaving machine comprises a control unit 35 for controlling the cam system 3, more particularly for suitably controlling the drive motor 25 and for suitably controlling the drive motor 33. The invention comprises a method for controlling a cam system 3 which drives heddle frames 1, 2, such that the heddle frames 1, 2 can be leveled and deleveled at an associated angular position of the cam system 3. As represented in figure 1, the control unit 35 can cooperate with an input unit 36 and with an output unit or display 37. The control unit 35 can also cooperate with a position sensor for determining the position of the drive shaft 23 of the cam system 3, for example with a known position sensor similar to the one described in EP 726.345 A1 or with a known position sensor arranged in the drive motor of a drive unit 24.
In figures 2 to 8, a part of the cam system 3 which pertains to the heddle frame 1 of figure 1 is schematically represented during various states for a known method for leveling and deleveling the heddle frame 1. As represented in figure 2, the cam system 3 is positioned such that the heddle frame 1 is at the lower limit 40 of the motional course 41, more particularly as represented in figure 1. When the lever 11 is in an angular position 38A, 39A or 40A, the associated heddle frame 1 is respectively at the upper limit 38, at the crossover position 39 or at the lower limit 40. Should the heddle frame 1 move over its motional course 41 during the weaving, the lever 11 and the lever 14 connected thereto are rotated over their angular course 41A during the weaving. During the execution of a known leveling method, after the stoppage of the cam system 3 the shaft end 27 is rotated from a state as represented in figure 2, via the states as represented in figures 3 to 7, into the leveled state as represented in figure 8. In the state represented in figure 2, the cam followers 21, 22 are in contact with the associated cams 19, 20 and are thus in a state which can likewise be assumed during the weaving, while, in the state represented in figure 8, the cam followers 21, 22 are in a leveled state. During the execution of a known deleveling method, after the stoppage of the cam system 3 the shaft end 27 is rotated from the leveled state as represented in figure 8, via the states as represented in figures 7 to 3, into the state as represented in figure 2. The associated path 42 of the position of the heddle frame 1 during the execution of the known leveling or deleveling method is represented in figure 9. It can be clearly seen in figure 9 that, during the execution of the known leveling and deleveling method, at set angular positions of the shaft ends 27, as represented, for example, in figures 3 and 4, the lower limit 40 of the motional course 41 of the heddle frame 1 is clearly breached. This is not only disadvantageous for the associated plane of warp threads, but can also lead to the formation of weave stripes after the weaving machine is restarted.
In figures 10 to 16, the cam system 3 is schematically represented during various states of a known method for leveling and deleveling a heddle frame 1. In these figures, the cam system 3 is positioned such that the heddle frame 1 is in the state as represented in figure 10 at the upper limit 38 of the motional course 41. The associated path 43 of the position of the heddle frame 1 during the execution of this known method is represented in figure 17 for the successive states of figures 10 to 16 during the leveling or for the successive states of figures 16 to 10 during the deleveling. It can be clearly seen in figure 17 that, during the execution of the known leveling and deleveling method, the upper limit 38 and the lower limit 40 of the motional course 41 of the heddle frame 1 are not breached.
In figures 18 to 24, analogously to figures 2 to 8, the cam system 3 is schematically represented during various states of a known method for leveling and deleveling a heddle frame 1. In these figures, the cam system 3 is positioned such that the heddle frame 1 is in the state as represented in figure 18 virtually in the crossover position 39. The associated path 44 of the positions of the heddle frame 1 during the execution of the known method for the leveling between the states of figures 18 to 24 or for the deleveling between the states of figures 24 to 18 is represented in figure 25. It can be clearly seen in figure 25 that, during the execution of this known leveling and deleveling method, the upper limit 38 and the lower limit 40 of the motional course 41 of the heddle frame 1 are not breached.
In figures 26 to 28, component parts of the cam system 3 of figure 1 which pertain to the heddle frames 1 and 2 are represented in various states during the execution of two weaving cycles 45, 46 of a set binding pattern 47 for the heddle frames. Such a binding pattern 47 forms in combination with a weft pattern a weaving pattern. In the represented illustrative embodiment, the binding pattern 47 consists of a 1/1 binding and thus comprises two weaving cycles 45 and 46. During a weaving cycle, a weft thread can be inserted. A weaving cycle normally takes place during one revolution of a main shaft or a reference drive shaft of the weaving machine. In figure 29, a motional path 48 of a heddle frame 1 during the two weaving cycles 45, 46 of the binding pattern 47 as a function of the angular position of a reference drive shaft of the weaving machine is represented with a dashed line. In addition, a motional path 49 of a heddle frame 2 is represented with a solid line. In the represented example, the reference drive shaft of the weaving machine has been chosen such that a beat-up of a weft thread takes place at 0° or 360° of the reference drive shaft. The heddle frames 1, 2 are also alternately commanded up and down by the cam system 3. It is also possible, of course, for the beat-up of a weft thread to take place at another angular position of the reference drive shaft.
As illustrated with reference to figures 2 to 9, the execution of a known leveling method starting from a state of the cam system 3 as represented in figure 26, or the execution of a known deleveling method which shall end in a state of the cam system 3 as represented in figure 26, shall lead to the breaching of the lower limit 40 of the motional course 41 of the heddle frame 1. The state represented in figure 26 corresponds with a state in which the angular position of the cams 19, 20 corresponds with an angular position of 180° in the first weaving cycle 45 of the binding pattern 47. The shaded region 50 represented in figure 29 with a dashed line indicates that region of the binding pattern 47 of the angular positions of the cams 19, 20 which would likewise lead to the breaching of the lower limit 40 of the motional course 41 by the heddle frame 1 during the execution of a known leveling or deleveling method. In the represented illustrative embodiment, this region 50 of the angular position of the cams 19, 20 virtually corresponds with a region of the angular position of the cams 19, 20 which is situated between 90° and 270° of the first weaving cycle 45 of the binding pattern 47.
As illustrated with reference to figures 10 to 17, the execution of a known leveling method starting from the state of the cam system 3 as represented in figure 28, or the execution of a known deleveling method which shall end in the state of the cam system 3 as represented in figure 28, shall lead to the breaching of the lower limit of the motional course 41 by the heddle frame 2. In the state represented in figure 28, the angular position of the cams 19, 20 corresponds with the angular position of the cams 19, 20 at 180° of the second weaving cycle 46 of the binding pattern 47. The shaded region 51 represented in figure 29 with a solid line indicates that region of the binding pattern 47 of the angular positions of the cams 19, 20 which would likewise lead to the breaching of the lower limit 40 of the motional course 41 by the heddle frame 2 during the execution of a known leveling or deleveling method. For the represented illustrative embodiment, this region 51 of the angular position of the cams 19, 20 virtually corresponds with a region of the angular position of the cams 19, 20 which is situated between 90° and 270° of the second weaving cycle 46 of the binding pattern 47.
As illustrated with reference to figures 18 to 25, the execution of a leveling method starting from the state of the cam system 3 as represented in figure 18, or the execution of a deleveling method which shall end in the state of the cam system 3 as represented in figure 18, shall not lead to the breaching of the lower limit 40 of the motional course 41 of the heddle frames 1, 2. The angular position of the cams 19, 20 in Figure 18 corresponds with an angular position of the cams 19, 20 at 0° in the first weaving cycle 45 or at 0° in the second weaving cycle 46 of the binding pattern 47.
The region 52 indicated in figure 29 indicates that region of the binding pattern 47 of the angular positions of the cams 19, 20 which would likewise not lead to the breaching of the lower limit 40 of the motional course 41 of the two heddle frames 1, 2 during the execution of a leveling or deleveling method. In the represented illustrative embodiment, this region 52 of the angular position of the cams 19, 20 virtually corresponds with a region of the angular position of the cams 19, 20 from 0° to 90° and from 270° to 360° of both weaving cycles 45, 46 of the binding pattern 47.
In figures 30 to 37, the cam system 3 is schematically represented during various states of a method according to the invention for leveling a heddle frame 1. If the weaving machine and the cam system 3 are stopped, for example after the detection of a thread break, a state as represented in figure 30 can be reached. In the state represented in figure 30, the cams 19, 20 are in an angular position 53 which virtually corresponds with, for example, an angular position of the cams 19, 20 at 180° of the first weaving cycle 45 of the binding pattern 47, and the cam followers 21, 22 are in contact with the cams 19, 20. In the further description, the angular position 53 is sometimes referred to as the stopping angular position or operating angular position, since the state represented in figure 30 is assumed after the stoppage of the weaving machine and can also be assumed during the normal operation of a weaving machine. The angular position 53 of the cams 19, 20 is situated in the region 50 from figure 29 and would thus lead, during a displacement of the bearing shaft 6 of the cam followers 4, 5, to the breaching of the lower limit 40 of the motional course 41 of the heddle frame 1.
As represented in figures 31 to 35, according to the leveling method according to the invention, during a displacement of the central bearing shaft 6 through the rotation of the shaft ends 27 by means of the drive motor 28, the cams 19, 20 are positioned into an intermediate angular position 54 which, in the represented illustrative embodiment, virtually corresponds with an angular position of the cams 19, 20 at 0° of the first weaving cycle 45 of the binding pattern 47. This intermediate angular position 54 of the cams 19, 20 is preferably chosen or set such that it is situated in the region 52 from figure 29, so that, during a displacement of the bearing shaft 6 through the rotation of the shaft ends 27, both heddle frames 1, 2 move within the upper limit 38 and within the lower limit 40 of their motional course 41. The intermediate angular position 54 of the cams 19, 20 as represented in figure 31 is reached from the angular position 53 as represented in figure 30 after the rotation of the cams 19, 20 by the controlled drive motor 25 of the drive unit 24. In the represented illustrative embodiment, the aforementioned intermediate angular position 54 roughly coincides with an angular position which leads to the virtual crossing of warp threads.
During the further displacement of the bearing shaft 6 of the control lever 4, 5, while the cams 19, 20 are positioned in an intermediate angular position 54, the states as represented in figures 32, 33, 34 and 35 are successively obtained. In the state represented in figure 35, the control lever 4 leans against a stop 29. In the state represented in figure 35, the cams 19, 20 can subsequently be arbitrarily rotated and positioned by the drive unit 24, since the cams 19, 20 cannot make contact with the cam followers 21, 22. As represented in figure 36, it is here possible to bring the cams 19, 20 into an arbitrary angular position 55.
According to a first embodiment, the angular position 55 of the cams 19, 20 in figure 36 virtually corresponds with the angular position 53 of the cams 19, 20 in figure 30, which virtually corresponds with an angular position of the cams 19, 20 at 180° of the first weaving cycle 45 of the binding pattern 47. In a weaving machine comprising a cam system 3 which is commanded via a drive unit of the weaving machine, for example a drive unit provided with a known pick-finder comprising a clutch system which allows a pick-finding motion only in some positions of the clutch system, the angular position 55 can be chosen such that, at this angular position, a pick-finding motion is performable. In the represented example, in which the cam system 3 is commanded by a dedicated drive motor 24, such an angular position 55 is less appropriate.
The associated path 58 of the position of the heddle frame 1 during the execution of the leveling method according to the invention as represented in figures 30 to 36 is represented in figure 37. It can be clearly seen in figure 37 that, during the execution of the leveling method according to the invention, in no single angular position of the shaft ends 27 is the upper limit 38 or the lower limit 40 of the motional course 41 of the heddle frame 1, between which the heddle frame 1, 2 moves during the weaving, breached.
It can, however, be advantageous to choose an angular position 55 of the cams 19, 20 which is different from the aforementioned angular position 53. This allows, for example, in the execution of a pick-finding procedure, in the event of a weft thread break, an angular position 55 of the cams 19, 20 to be chosen which corresponds with an angular position of the cams 19, 20 during the previous weaving cycle 45 of the binding pattern 47. During a following reverse deleveling, this allows a shed to be formed in which a weft thread has already been inserted, more particularly in which a previous weft thread has been wrongly inserted and can be removed.
According to another variant, an angular position 55 of the cams 19, 20 can be chosen such that it corresponds with the intermediate angular position 54 of the cams 19, 20 of figure 31, which virtually corresponds with an angular position of the cams 19, 20 at 0° of the first weaving cycle 45 of the binding pattern 47. This is advantageous in order, for example, following on from a leveling method according to the invention, subsequently to apply a deleveling method according to the invention. This means, for example, that after a detection of a warp thread break and after the repair of the warp thread break the cam system 3 can be brought into a position which is advantageous to the execution of a deleveling according to the invention. As yet to be described below, the angular position 55 can also be chosen virtually equal to the intermediate angular position 56 of figure 40.
The leveling method according to the invention is illustrated with reference to the flow chart as represented in the part 68 of figure 38. At a step 60, the leveling method according to the invention commences, for example after the stoppage of the weaving machine as a consequence of a thread break. Next, a determinant algorithm 61 can take a decision on the basis of set parameters 62 to advance the method with a step 63 or with a step 64, in which a displacement 69 of the bearing shaft 6 takes place. The parameters 62 on which the determinant algorithm 61 can base a decision are, for example, at least one angular position 53, at least one intermediate angular position 54 and/or at least one angular position 55 which can be used in specific leveling methods according to the invention, such as a specific method for use in a warp thread break, for use in a weft break, or for use in other circumstances. Further parameters 62 comprise, for example, regions 50, 51 and 52 of a binding pattern 47, the type of cams used, the binding pattern used, the cause of the weaving machine stoppage and/or yet other parameters. If the determinant algorithm 61 decides to proceed to a step 63, then the cams 19, 20 are positioned from an angular position 53 into an intermediate angular position 54 before the method is advanced with a step 64. At the step 64, the shaft end 27 is rotated from a state as represented, for example, in figure 31 into a leveled state as represented, for example, in figure 35, so that the shaft end 6 is displaced.
In the represented illustrative embodiment, the determinant algorithm 61 can be elaborated, for example, such that, if the angular position 53 of the cams 19, 20 is in the region 50 or 51, the method is advanced with a step 63, and if the angular position 53 of the cams 19, 20 is in the region 52, the method is advanced with a step 64. The determinant algorithm 61 can also be elaborated, for example, such that, in whichever angular position 53 of the cams 19, 20, the method is advanced with a step 63 so as to position the cams 19, 20, for example, always in a previously input intermediate angular position 54. Of course, other determinant algorithms 61 are possible, which can be based on other parameters 62. After the rotation of the shaft end 27 in a step 64, a determinant algorithm 65 can take a decision on the basis of set parameters 62 to advance the method with a step 66 or a step 67. If the determinant algorithm 65 decides to proceed to a step 66, then the cams 19, 20 are positioned from the intermediate angular position 54 into an angular position 55 before the method is completed with a step 67. Following the completion of the leveling method with a step 67, for example after the repair of a warp thread, after the repair of a weft thread or after, for example, the execution of a pick-finding procedure, a deleveling method according to the invention can be commenced with a step 70 as represented in part 78 of figure 38. After this, the normal operation of the weaving machine can be started automatically or following a command of the operator.
A method according to the invention for deleveling a heddle frame 1 is illustrated with reference to figures 39 to 46. In order to be able to remove a weft thread after the execution of a deleveling method, as represented in the state in figure 45, the cams 19, 20 should be in an angular position 57 which, in the represented example, approximately matches an angular position of the cams 19, 20 at 180° of the first weaving cycle 45 of the binding pattern 47, in which the cam followers 21, 22 are in contact with the cams 19, 20 and in which an at least partially open shed is formed between the heddle frames 1, 2. The angular position 57 of the cams 19, 20 is situated in the region 50 from figure 29 and would thus lead, during a displacement of the bearing shaft 6 of the cam followers 4, 5, to the breaching of the lower limit 40 of the motional course 41 of the heddle frame 1.
As represented in figures 40 to 44, according to a deleveling method according to the invention, during a displacement of the central bearing shaft 6 through the rotation of the shaft ends 27 by means of the drive motor 28, the cams 19, 20 are positioned into an intermediate angular position 56 which virtually corresponds with an angular position of the cams 19, 20 at 0° of the first weaving cycle 45 of the binding pattern 47. This intermediate angular position 56 of the cams 19, 20 is preferably chosen such that it is situated in the region 52 from figure 29, so that, during a displacement of the bearing shaft 6 through the rotation of the shaft ends 27, both heddle frames 1, 2 move within the upper limit 38 and within the lower limit 40 of the motional course 41. The angular position 57 of the cams 19, 20 as represented in figure 45 is reached from the intermediate angular position 56 as represented in figure 44 after the rotation of the cams 19, 20 by the controlled drive motor 25 of the drive unit 24. The drive motor 25 is here moved, for example, at low speed or at slow motion. According to the invention, this rotation takes place after a displacement 79 of the bearing shaft 6. In this illustrative embodiment, the aforementioned intermediate angular position 56 roughly coincides with an angular position which leads to the virtual crossing of warp threads. The intermediate angular position 56 for the deleveling can belong to an earlier weaving cycle than the weaving cycle for the intermediate angular position 54 for the leveling, yet in both weaving cycles an intermediate angular position 54, 56 normally roughly coincides with an angular position which leads to the crossing of warp threads, more particularly the crossover position 39 of the heddle frames 1, 2.
During the further displacement of the bearing shaft 6 of the control levers 4, 5, while the cams 19, 20 are positioned into an intermediate angular position 56; the states as represented in figures 40, 41, 42, 43 and 44 are successively obtained. In the state represented in figure 40, the control lever 4 leans against a stop 29. In the state represented in figure 40, the cams 19, 20 can subsequently be arbitrarily rotated and positioned by the drive unit 24, since the cams 19, 20 can make no contact with the cam followers 21, 22. As represented in figure 36, it is here possible to bring the cams 19, 20 from a set angular position 55 into the intermediate angular position 56. As described above in connection with the leveling method, the angular position 55, can also correspond for example, with the angular position 57 of the cams 19, 20 of figure 45. It is likewise possible to choose the angular position 55 of the cams 19, 20 differently from the angular position 57. Thus the aforementioned angular position, for example during a deleveling as a consequence of a weft thread break, can match the intermediate angular position 56 which is assumed after a pick-finding procedure from an intermediate angular position 54 of a preceding leveling. In the event of, for example, a preceding leveling as a consequence of a warp thread break, the intermediate angular position 56 can nevertheless also match the intermediate angular position 54.
In the further description, the angular position 57 is sometimes referred to as the starting angular position or operating angular position, since the state represented in figure 45 can also be assumed in order to start the weaving machine with the cam system 3 without difficulty, and to obtain a weave without a weave stripe after the start-up. This angular position 57 can match, for example, the angular position 53 of figure 30, which was assumed after the stoppage of the normal operation of the weaving machine, in other words prior to the execution of a leveling method. In the represented illustrative embodiment, as the starting angular position 40° can be chosen, for example, in other words the weaving machine can be started, for example, from an angular position for use with a partially closed shed.
The associated path 59 of the position of the heddle frame 1 during the execution of the deleveling method according to the invention, as represented in figures 39 to 45, is represented in figure 46. It can be clearly seen in figure 46 that, during the execution of the deleveling method according to the invention, at no single angular position of the shaft ends 27 is the upper limit 38 or the lower limit 40 of the motional course 41 of the heddle frame 1 during the weaving, breached.
The deleveling method according to the invention is further illustrated with reference to the flow chart as represented in the part 78 of figure 38. Following the stoppage of the weaving machine, owing to a faulty weft thread, a leveling method can be automatically executed as represented in the part 68 of figure 38. In the event of, for example, a weft thread break, after a rotation of the cams 19, 20 according to a step 66, a step 80 can be executed, preferably automatically, in which the cam system 3 is positioned into a predetermined angular position which is situated in a previous weaving cycle, preferably in a region 52 of a previous weaving cycle. During such a step 80, a so-called pick-finding is thus carried out, in which the cam system 3 is brought into an angular position of a previous weaving cycle. According to a variant embodiment, an operator can give a command to execute a step 80, although it is preferable to execute a step 80 automatically after the leveling. The so-called pick-finding occurs at relatively low speed of the drive motor 25.
A deleveling method from a step 70 can commence following a command of an operator. A determinant algorithm 71 can take a decision on the basis of set parameters 72 to advance the method with a step 73 or a step 74, in which a displacement 79 of the bearing shaft 6 takes place. The parameters 72 on which the determinant algorithm 71 can base a decision are, for example, at least one angular position 57, at least one intermediate angular position 56, at least one angular position 55 for use in specific deleveling methods according to the invention, for example in connection with a warp thread break, a weft break or some other circumstance. The parameters can also comprise regions 50, 51 and 52 of a binding pattern 47, the type of cams used, the binding pattern used, the cause of the weaving machine stoppage or other parameters.
If the determinant algorithm 71 decides to proceed to a step 73, then the cams 19, 20 are positioned from the angular position 55 into an intermediate angular position 56 before the method is advanced with step 74. The determinant algorithm 71 can take decisions, for example, analogously to the determinant algorithm 65. It is possible, of course, that, after the execution of a step 80, the cams 19, 20 have already been positioned into the intermediate angular position 56, so that it is possible to commence directly with the step 74. At a step 74, the shaft end 27 is rotated from a leveled state as represented, for example, in figure 40 into the state as represented, for example, in figure 44, so that the shaft end 6 is displaced. After the rotation of the shaft end 27 in a step 74, a determinant algorithm 75 can take a decision on the basis of set parameters 72 to advance the method with a step 76 or a step 77.
If the determinant algorithm 75, after the execution of the step 74, decides to proceed to a step 76, then the cams 19, 20 are positioned from the intermediate angular position 56 into an angular position 57, in which, for example, a faulty weft thread, with the shed partially open, can be removed. The step 76 is executed, for example, where the angular position 57 of the cams 19, 20 is in the region 50 or 51 of figure 29 and where a faulty weft thread needs to be removed. After the execution of the step 76 and after, for example, the removal of the faulty weft thread, a step 77 can then take place following a command of the operator, in which the cams 19, 20 are positioned into a starting angular position 81, in which the weaving machine can then automatically be started once this starting angular position 81 is reached. The starting angular position 81 is visible in figure 47. The path 82, represented in figure 47, of the position of the heddle frame 1 during the execution of the deleveling method according to the invention from a state represented in figure 39 into a state represented in figure 45 is here followed by a further rotation of the cams 19, 20 toward the starting angular position 81. Once this starting angular position 81 is reached, the weaving is started and the heddle frame 1 then follows the motional path 48 indicated in figure 47.
According to a variant, the determinant algorithm 75, after the execution of the step 74, for example in the event of a warp thread break, following a command of an operator, can directly decide to proceed to a step 77 and to position the cams 19, 20 into a starting angular position 81. Once this starting angular position 81 has been reached, the weaving machine can automatically be started. The determinant algorithm 75 can also be realized, for example, such that, in whichever intermediate angular position 56 of the cams 19, 20, the method is constantly advanced with a step 76, in which the cams 19, 20, following a command of an operator, are always positioned into a previously input angular position 57. Following a second command of the operator, the weaving machine can then be positioned into a predetermined starting angular position 81 and subsequently started from this starting angular position 81, whether automatically or not. Of course, other determinant algorithms 75 can also be chosen, which are based, for example, on other parameters 72. Given an angular position 56, if the shed is sufficiently open to allow the removal of a weft thread, the method can be advanced, for example, with step 77, without prior execution of the step 76. It is also possible, of course, to choose the angular position 57 equal to the angular position 81.
By means of the input unit 36, all angular positions can be input, more particularly angular positions 53, 55, 57, 81 and intermediate angular positions 54, 56 pertaining to each heddle frame 1, 2. It is also possible to input a plurality of angular positions 53, 55, 57, 81 and a plurality of intermediate angular positions 54, 56 per heddle frame 1, 2 for use in specific leveling and deleveling methods according to the invention. Such angular positions can also be input via software or in some other manner. The specific methods can pertain to a warp thread break, a weft break or yet another circumstance. It is also readily possible to input the regions 50, 51, 52 of a binding pattern 47, so that, according to set algorithms, the control unit 35 can automatically determine in a given situation an advantageous angular position 53, 55, 57, 81 or an advantageous intermediate angular position 54, 56. It is likewise possible to input the types of cams used or the binding pattern used, so that, via set algorithms, the control unit 35 can automatically determine the regions 50, 51 and 52 of the binding pattern 47 and can then automatically determine in the given situation advantageous angular positions 53, 55, 57, 81 and intermediate angular positions 54, 56. The control unit 35 can control the drive motor 25 for rotating the cams 19, 20 and the drive motor 33 for rotating the shaft ends 27, in order to displace the bearing shaft 6 and rotate the cam system 3 according to a method according to the invention.
A method according to the invention described with reference to the represented illustrative embodiment is particularly suitable for use in weaving machines which a weave with a 1/1, a 2/1, a 3/1, a 4/1 or whichever binding pattern, in which method no warp threads remain in the lowermost position as the warp threads cross. Were a part of the warp threads to remain in a lowermost position, for example, then this warp threads part can admittedly be subject to heavy loads, but the remaining warp threads part shall be less heavily loaded according to the invention. According to a further embodiment, care can always be taken to ensure, irrespective of the chosen binding pattern, that all warp threads move constantly in a direction toward a crossover position at which set warp threads cross. In this case, a method according to the invention is likewise advantageous for all warp threads.
According to a variant embodiment, an angular position 53 can be chosen which is situated, for example, between 290° of the current weaving cycle and 30° of the following weaving cycle, wherein a weaving machine is stopped. Through the following automatic and suitable rotation of the cams 19, 20, an intermediate angular position 54 of, for example, 0° can be reached, in which, subsequently, a displacement 69 of the bearing shaft 6 takes place. In the event of, for example, a stoppage as a consequence of a weft thread break, after a displacement 69 of the bearing shaft 6 through the automatic and suitable rotation of the cams 19, 20, a second intermediate angular position 56 of, for example, 300° can be reached, for example an angular position of 300° pertaining to a previous weaving cycle. Subsequently, the cam system 3 remains in a thus leveled condition until an operator operates the weaving machine to start the deleveling. After a displacement 79 of the bearing shaft 6 with the cams 19, 20 into the second intermediate angular position 56, a deleveled condition is reached. After this, the cams 19, 20 can be rotated, preferably automatically, into an angular position 57 of, for example, 70°, in order to allow, for example, with a somewhat open shed, a wrongly inserted weft thread to be removed from a shed. The angular position 57 is here an angular position in which the shed is partially open. After this, the operator can operate the weaving machine in order to rotate the cams 19, 20 into a starting angular position 81 for the starting of the weaving machine, for example a starting angular position of 45°. When moved between an angular position of 70° to 45°, the cam system 3 is rotated oppositely to the rotational direction during the weaving. Subsequently, once the starting angular position 81 is reached, the weaving machine can start automatically. According to a variant, it is also possible in this case to start the weaving machine directly at an aforementioned angular position 57 of 70°, which angular position then likewise acts as a starting angular position. It is clear that the starting angular position 81 is not limited to 45°, but rather according to a variant embodiment can be chosen for example, between 340° in the previous weaving cycle and 50° in the current weaving cycle, more particularly, for example, between 0° and 45° in the current weaving cycle.
In the case of a weaving machine stoppage as a consequence of, for example, a broken warp thread, or in the case of a manual stoppage, the cam system 3, after a displacement 79 of the bearing shaft 6 during the deleveling, can be brought directly into a starting angular position 81 of, for example, 40° and the weaving machine can subsequently be started automatically. In this case, the intermediate angular positions 54 and 56 can be chosen equal to each other, this means after the displacement of the bearing shaft 6 during the leveling and prior to the displacement of the bearing shaft 6 during the deleveling, the cams 19, 20 are not in this case rotated. From the starting angular position 81, the weaving machine can be started automatically or the weaving machine can be started only after a command of the operator.
It is clear that, should a plurality of weft threads need to be removed, the various weft threads can successively be removed by successive so-called pick-finding. After the removal of the last weft thread, the weaving machine with the cam system can be brought back into an angular position for the starting of the weaving machine.
If, in a variant embodiment, it is not the warp threads in the lowermost position which are at risk of being more heavily loaded during leveling or deleveling than during the weaving, but rather the warp threads in the uppermost position, the method according to the invention can be similarly applied. This can be useful during the weaving of a 1/2, a 1/3, a 1/4 or whichever binding, wherein no warp threads remain in an uppermost position as the warp threads cross.
In the represented embodiment, the cam system 3 comprises a drive motor 25. According to a non-represented variant, this drive motor 25 can likewise guarantee to drive other parts of the weaving machine. Such a drive motor 25 can be connected via a clutch, for example, to the drive system for the sley of the weaving machine. Should the drive motor 25, for example the cam system 3, need to rotate onward or back, the drive motor 25 can in this case be decoupled from the drive system for the sley. In this latter case, the drive motor 25 can be connected to the cam system 3 in a manner as described in EP 726.345 A1 . This allows the cam system 3 to continue rotating during a so-called pick-finding, without the sley of the weaving machine moving along with it.
It is clear that the various movements should not always occur successively, but that a relatively small overlap in the time of the various movements is possible. For instance, the adjusting unit 28 can already partially displace the bearing shaft 6 before the drive shaft 23 of the cam system 3 has yet fully reached the intermediate angular position 54 or 56. Analogously, the adjusting unit 28 can already partially move back the bearing shaft 6 before the drive shaft 23 has yet fully reached the intermediate angular position 54 or 56.
In the description, the term "leveling" is used to indicate that the heddle frames are moved from the weaving condition into a condition in which all heddle frames are arranged approximately evenly in height. The term "deleveling" is here used to bring the heddle frames from a leveled condition back into a weaving condition.
The method according to the invention offers the advantage that the shed which is formed during the leveling or during the deleveling never becomes larger than a shed which is formed in normal weaving. This offers the advantage that no overstretching or excessive elongation of warp threads takes place. Moreover, the structure for the leveling or deleveling, which is fastened directly to the frame of the cam system, offers good mechanical stability during the weaving. The method according to the invention is also advantageous for the prevention of stripes in the weave, which are formed after the weaving machine is restarted following a weaving machine stoppage. Since the heddle frames 1, 2 remain within their motional course 41 both during the leveling and deleveling and during the weaving, a weaving machine according to the invention also allows a restriction of the installation space for, in particular, the heddle frames 1, 2, the levers 11, 14 and the connecting rod 12.
It is clear that, in a given case, after a known leveling method a deleveling method according to the invention can be used. Other combinations of known leveling and deleveling methods and leveling and deleveling methods according to the invention are possible.
It is clear that a weaving machine with the cam system and a method according to the invention can be used in several types of weaving machines, such as in pneumatic weaving machines, gripper weaving machines, projectile weaving machines, gripper shuttle weaving machines, water jet weaving machines and other types of weaving machines. The method according to the invention can also be used on existing weaving machines.
The weaving machine and the method according to the invention are not limited, of course, to the embodiments described by way of example and represented in the drawings, but can be realized within the scope of the claims according to various variants and combinations of the represented embodiments.

Claims

A method for driving a cam system (3) which drives heddle frames (1, 2) in a weaving machine and which comprises cams (19, 20) connected to a drive (24) and cam followers arranged on a central bearing shaft (6) which for levelling the heddle frames (1,2) is displaceable by a drive (30), characterized in that, during a displacement (69, 79) of the central bearing shaft (6) of the cam system (3), the cams (19, 20) of the cam system (3) are positioned in an intermediate angular position (54, 56), so that the heddle frames (1, 2), during a displacement (69, 79) of the central bearing shaft (6), move substantially between an upper limit (40) and a lower limit (38) of their motional course (41).
The method as claimed in claim 1, characterized in that the method is applied during the leveling of heddle frames (1, 2).
The method as claimed in claim 2, characterized in that, before a displacement (69) of the central bearing shaft (6) of the cam system (3) takes place, the cams (19, 20) of the cam system (3) are positioned by means of a determinant algorithm (61) from a set angular position (53) into an intermediate angular position (54).
The method as claimed in claim 2 or 3, characterized in that, after a displacement (69) of the central bearing shaft (6) of the cam system (3) has taken place, the cams (19, 20) of the cam system (3) are positioned by means of a determinant algorithm (65) from an intermediate angular position (54) into a set angular position (55).
The method as claimed in claim 1, characterized in that the method is applied during the deleveling of heddle frames (1, 2).
The method as claimed in claim 5, characterized in that, after a displacement (79) of the central bearing shaft (6) of the cam system (3) has taken place, the cams (19, 20) of the cam system (3) are positioned by means of a determinant algorithm (75) from an intermediate angular position (56) into a set angular position (57, 81).
The method as claimed in claim 5 or 6, characterized in that, before a displacement (79) of the central bearing shaft (6) of the cam system (3) takes place, the cams (19, 20) of the cam system (3) are positioned by means of a determinant algorithm (71) from a set angular position (55) into an intermediate angular position (56).
A method for operating a cam system (3) which drives heddle frames (1, 2) of a weaving machine and which comprises cams (19, 20) connected to a drive (24) and cam followers arranged on a central bearing shaft (6) which for levelling the heddle frames (1, 2) is displaceable by a drive (30), characterized in that after a stop of the weaving machine the cams (19, 20) are moved into a defined angular position (54,56) before the central shaft (6) is displaced for levelling the heddle frames (1, 2).
A weaving machine comprising a cam system (3) for driving heddle frames (1, 2) which cam system comprises a central bearing shaft (6) for cam followers (21, 22), a drive motor (33) for displacing the central bearing shaft (6), cams (19, 20) and a drive motor (25) for rotating the cams (19, 20) which drive motors are controlled by a control unit (35), characterized in that the control unit (35) before displacing the central bearing shaft (6) positions the cams (19, 20) of the cam system (3) in an intermediate angular position, so that the heddle frames (1, 2), during displacement of the central bearing shaft (6) move substantially between an upper limit (40) and a lower limit (38) of their motional course (41) during weaving.
The weaving machine as claimed in claim 9, characterized in that the cam system (3) comprises a control lever (4, 5) with cam followers (21, 22) which are mounted on a bearing shaft (6), the bearing shaft (6) being displaceable by an adjusting unit (28).
The weaving machine as claimed in claim 9, characterized in that the bearing shaft (6) is arranged such that it is displaceable via shaft ends (27) located eccentrically with respect to the bearing shaft (6).
The weaving machine as claimed in one of claims 9 to 11, characterized in that the cam system (3) comprises an adjusting unit (28), which can be driven by a drive motor (33).