EP4151787A1

EP4151787A1 - Method for determining a configuration of a drive mechanism with a moving element, moving element, and system

Info

Publication number: EP4151787A1
Application number: EP21196970.4A
Authority: EP
Inventors: Cédric Ally; Dimitri COEMELCK; Dirk Sampers; Kristof Roelstraete
Original assignee: Picanol NV
Current assignee: Picanol NV
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2023-03-22
Also published as: BE1029723B1; WO2023041334A1; BE1029723A1

Abstract

The invention relates to a method for determining configuration of a drive mechanism (2) having a moving element (12, 16, 17, 20, 21, 22) for driving a heald frame (1), wherein the sensor device (40) comprises a target set (41) provided on the moving element (12, 16, 17, 20, 21, 22) with an upper target (43) and a lower target (45), and the sensor device (40) comprises a sensor element (42) arranged stationary on the weaving machine, wherein the method comprises operating the drive mechanism (2) to move the moving element (12, 16, 17, 20, 21, 22) so that the target set (41) passes the sensor element (42), detecting with the sensor element (42) the presence of the upper target (43) and the lower target (45) within the sensing range, and determining an upper target detecting moment (63) and a lower target detecting moment (65) in a weaving cycle upon detecting the upper target (43) and the lower target (45), and the method comprises detecting with the sensor element (42) the presence of a middle target (44) within the sensing range, wherein the middle target (44) is provided on the moving element (12, 16, 17, 20, 21, 22) of the drive mechanism (2) and arranged between the upper target (43) and the lower target (45), determining a middle target detecting moment (64) in the weaving cycle upon detecting the middle target (44), and determining a configuration of the drive mechanism (2) based on the upper target detecting moment (63), the middle target detecting moment (64), and the lower target detecting moment (65). The invention further relates to a moving element of a drive mechanism for driving a heald frame of a weaving machine, and to a system comprising a moving element and a sensor device.

Description

TECHNICAL FIELD AND PRIOR ART

The invention relates to a method for determining with a sensor device a configuration of a drive mechanism having a moving element for driving a heald frame of a weaving machine. The invention further relates to a moving element of a drive mechanism for driving a heald frame of a weaving machine, and to a system comprising a moving element and a sensor device.
Different types of drive mechanisms are known for driving heald frames of a weaving machine to move up and down heald frames, for example a cam mechanism as shown in US5273079 , a dobby mechanism, an eccentric mechanism as shown in WO2004081113A1 , or a mechanism in which each heald frame is driven by a separate drive motor independently from the weaving machine as shown in EP3341509A1 .
More particular, EP3341509A1 shows the drive mechanism comprising a crank rotating about a crank axis, a coupling rod, and a lever having a first arm and a second arm, wherein the lever is swivelable to-and-fro about a swivel axis between an upper position and a lower position, and wherein the coupling rod is linked to the crank by a first hinged joint, which first hinged joint is eccentric to the crank axis, wherein the coupling rod is linked to the first arm of the lever by a second hinged joint, and wherein a location of the second hinged joint is adjustable with respect to the first arm of the lever for adjusting a stroke of the heald frame moved by the drive mechanism. EP3341509A1 further shows a sensor device comprising a target set arranged on the lever with a first target and a second target, and a detector arranged stationary on the weaving machine in a measuring position, wherein the targets of the target set have different characteristics for generating a first signal when approaching the measuring position from the upper position or when departing from the measuring position towards the upper position and for generating a second signal when approaching the measuring position from the lower position or when departing from the measuring position towards the lower position, wherein the second signal differs from the first signal. In accordance with EP3341509A1 , movement profiles or movement courses are known in advance for different strokes. Therefore, a stroke can be determined based on the first signal, the second signal and the known movement profiles.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a method for determining with a sensor device a configuration of a drive mechanism having a moving element for driving a heald frame of a weaving machine requiring less or even no advance information of a movement profile. It is a further object of the invention to provide a moving element of a drive mechanism for driving a heald frame of a weaving machine allowing such a determination, and to a system comprising a moving element and a sensor device.
According to a first aspect, a method for determining with a sensor device a configuration of a drive mechanism having a moving element for driving a heald frame of a weaving machine is provided, wherein the sensor device comprises a target set provided on the moving element of the drive mechanism with an upper target, a middle target and a lower target, wherein the middle target is arranged between the upper target and the lower target, and the sensor device comprises a sensor element arranged stationary on the weaving machine and configured for detecting a presence of the targets of the target set within a sensing range. The method comprises operating the drive mechanism to move the moving element so that the target set passes the sensor element, detecting with the sensor element the presence of the upper target, the middle target, and the lower target within the sensing range, determining an upper target detecting moment in a weaving cycle upon detecting the upper target, determining a middle target detecting moment in the weaving cycle upon detecting the middle target, and determining a lower target detecting moment in a weaving cycle upon detecting the lower target, and determining a configuration of the drive mechanism based on the upper target detecting moment, the middle target detecting moment, and the lower target detecting moment.
Throughout this application, the indefinite article "a" or "an" means "one or more". In particular, the drive mechanism may comprise more than one moving element, wherein each moving element is configured for driving one heald frame. Reference to "a first element" does not mandate presence of a "second element". Further, the expressions "first" and "second" are only used to distinguish one element from another element and not to indicate any order of the elements.
Although in the application, the expressions "upper" and "lower" are used in conformity with a movement of the heald frame driven by the drive mechanism, the method can also be used with a moving element, which moves left to right, wherein the sensor element is approached by the targets provided on the moving element from the left and from the right depending on the movement direction of the moving element.
In the following, the expression determined target detecting moment will be used to refer to one, several or all of a determined upper target detecting moment, a determined lower target detecting moment, and a determined middle target detecting moment.
In the context of the application, a moment in the weaving cycle is defined as a moment in relation to an angle of the weaving machine, for example a moment in which the moving element reaches or is in a certain position in relation to an angle of the weaving machine.
In the context of the application, a configuration of a drive mechanism is defined as a configuration or set-up associated with at least one settable configuration parameter of a movement profile of the drive mechanism selected of the group comprising a stroke, a zero-crossing moment, a crossing moment, a movement profile type, and/or a binding pattern. In other words, by determining the configuration of a drive mechanism at least one of the stroke, the zero-crossing moment, the crossing moment, the movement profile type, and/or the binding pattern are determined, allowing a determination of the movement profile, i.e. a movement path or curve of the moving element.
In the context of the application, the stroke, also referred to as stroke length, is the distance travelled by the moving element between two extreme positions also referred to as reversal points, typically an upper extreme position and a lower extreme position. The stroke of the moving element is the same as or proportional to the stroke of the heald frame driven by the moving element. A position in the middle of the travelled distance of the moving element, with the same distance to both extreme positions, is referred to as zero position. A zero-crossing moment is defined as a moment in the weaving cycle at which the moving element passes the zero position during an upward and a downward movement.
In weaving machines, depending on a drive mechanism and/or a configuration of a drive mechanism so called symmetrical movements and asymmetrical movements of a moving element and thus of the heald frame driven by the moving element are possible, which are referred to in the context of the application as movement profile types. When using an asymmetrical movement, typically the movement profile is different for the lower warp threads than for the upper warp threads.
A crossing moment is defined as a moment in the weaving cycle, in which the moving element is in a position where the moving element should cross itself when moving from one extreme position to the other extreme position. The crossing moment may differ from a zero-crossing moment, in particular for asymmetrical movement profile types. A position of the moving element at the crossing moment is referred to as crossing position. A distance between the zero position and the crossing position is referred to as crossing height.
A binding pattern or weaving pattern is defined as a pattern in which weft threads and warp threads interlace. Depending on the binding pattern, not all heald frames are moved from one extreme position to the other extreme position in each weaving cycle.
The configuration of the drive mechanism can be set-up to adapt the movement profile of the moving element of the drive mechanism, and thus the heald frame driven by the moving element, to different weaving conditions and/or weaving patterns. In particular, depending on the drive mechanism, the configuration can be set-up to alter one or more configuration parameters selected for example from the group comprising the stroke, the zero-crossing moment, the crossing moment, the crossing height, the movement profile type, and/or the binding pattern.
According to the invention, a method is provided which allows the determination of the configuration of the drive mechanism requiring no or at least only little advance information about any configuration parameter by observing a movement of the moving element using a target set with three targets, namely an upper target, a middle target, and a lower target, so that the configuration of the drive mechanism can be determined in embodiments without the necessity of any input in a control device of the weaving machine from a user or operator of the weaving machine.
The determined configuration in embodiments of the method is stored in a control device of the weaving machine. The determined configuration can thus be used for a subsequent operation of the weaving machine and/or for set-up of the drive mechanism to set-up the drive mechanism with a desired configuration. The determined configuration in one embodiment is used to optimize the revolution speed of the weaving machine and/or to optimize the insertion parameters of the weaving machine for a set revolution speed of the weaving machine.
In an embodiment, the sensor element is a Hall sensor, wherein the targets are magnets provided at the moving element, in particular at a side end of the moving element, wherein the method comprises detecting with the sensor element the magnets when moving the magnets into or out of the sensing range. In an alternative embodiment, the targets are separate elements provided at the moving element, for example elements such as blocks that are fixed or glued to the moving element, in particular that are fixed to the moving element at a side of the moving element. A fixing or gluing may be performed per block individually or via an assembly of several blocks.
In other embodiments, the sensor element is a proximity sensor, wherein the targets are protrusions provided at the moving element, in particular at a side end of the moving element, which protrusions are separated by notches, wherein the method comprises detecting with the sensor element rising edges of the targets when moving the targets into the sensing range. This allows the targets to be manufactured integrally with the moving element. In addition or in alternative to the rising edges, in one embodiment falling edges are also detected and processed for determining the configuration of the drive mechanism.
In one embodiment, the drive mechanism is operated in a weaving direction to move the moving element back-and-forth so that the target set passes the sensor element from below and from above, wherein the method for determining the configuration of the drive mechanism comprises detecting the presence of the targets within the sensing range when passing the sensor element from below and from above, and determining target detecting moments including a first upper target detecting moment in the weaving cycle upon detecting the upper target when passing the sensor element from below, a second upper target detecting moment in the weaving cycle upon detecting the upper target when passing the sensor element from above, a first middle target detecting moment in the weaving cycle upon detecting the middle target when passing the sensor element from below, a second middle target detecting moment in the weaving cycle upon detecting the middle target when passing the sensor element from above, a first lower target detecting moment in the weaving cycle upon detecting the lower target when passing the sensor element from below, and a second lower target detecting moment in the weaving cycle upon detecting the lower target when passing the sensor element from above.
In the context of the application, the weaving direction is defined as a movement direction used in normal operation of the weaving machine. When operating the drive mechanism in the weaving direction, the moving element within one, two or several weaving cycles is moved back-and-forth to move a driven heald frame up and down. In accordance with the application, the drive mechanism is operated for a sufficient period so that each target of the target set passes the sensor element at least once from above and once from below, wherein - using three targets - six target detecting moments are identified, for example using rising edges, which can be used for a subsequent determination of the configuration of the drive mechanism.
In accordance with the above, although in the application and the claims the expressions "from below" and "from above" are used in conformity with a movement of the heald frames driven by the drive mechanism, the method can also be used with a moving element, which moves left to right, wherein the sensor element is approached by the targets provided on the moving element from the left and from the right depending on the movement direction of the moving element.
In one embodiment, the drive mechanism is operated in a reverse direction to move the moving element back-and-forth so that the target set passes the sensor element from below and from above, wherein the method for determining the configuration of the drive mechanism further comprises detecting the presence of the targets within the sensing range when passing the sensor element from below and from above, and determining target detecting moments including a third upper target detecting moment in the weaving cycle upon detecting the upper target when passing the sensor element from below, a fourth upper target detecting moment in the weaving cycle upon detecting the upper target when passing the sensor element from above, a third middle target detecting moment in the weaving cycle upon detecting the middle target when passing the sensor element from below, a fourth middle target detecting moment in the weaving cycle upon detecting the middle target when passing the sensor element from above, a third lower target detecting moment in the weaving cycle upon detecting the lower target when passing the sensor element from below, and a fourth lower target detecting moment in the weaving cycle upon detecting the lower target when passing the sensor element from above.
In the context of the application, the reverse direction is defined as a direction opposite to the weaving direction. When operating the drive mechanism in the weaving direction and in the reverse direction for a sufficient period so that each target of the target set passes the sensor element twice from above and twice from below, twelve target detecting moments are identified, for example using rising edges, which can be used for a subsequent determination of the configuration of the drive mechanism.
In one embodiment, determining the configuration of the drive mechanism comprises determining a zero-crossing moment in the weaving cycle when the moving element is in a zero position based on two determined middle target detecting moments, which determined middle target detecting moments have been determined upon detecting the middle target when passing the sensor element from above and from below, wherein in particular the middle target is arranged symmetrically to a zero position line when the moving element is in a zero position and the sensor element is arranged at a height of the zero position line.
As defined above, the zero position is the position in the middle of the stroke or travel distance of the moving element. For determining the zero position, a moment when a midpoint of the middle target is at the height of the sensor element is determined, wherein in embodiments, the sensor is arranged at the height of the zero position line and the middle target is arranged such that the midpoint is at the zero position line in the zero position. Depending on the embodiment, two middle target detecting moments are determined, namely the first and the second middle target detecting moment or the third and the fourth middle target detecting moment, or all four middle target detecting moments are determined. For determining the moment when the midpoint of the middle target is at the height of the sensor element, two of these determined middle target detecting moments are used, in particular the first and the second middle target detecting moment or the first and the fourth middle target detecting moment, the third and the fourth middle target detecting moment, or the third and the second middle target detecting moment. In other words, moments, when the middle target is detected by the sensor element, when moving the middle target past the sensor element from two opposite directions, are used for determining a moment, when a midpoint of the middle target is at the height of the sensor element. Of course, embodiments are also conceivable in which more than two determined middle target detecting moments are used.
In an embodiment, determining the configuration of the drive mechanism further comprises determining a movement profile type, wherein information about different movement profile types is pre-stored, and the movement profile type is determined based on the determined zero-crossing moment.
The movement profile types can comprise a symmetrical type and an asymmetrical type. In embodiments, different symmetrical types and/or asymmetrical types are considered. The method makes use of the characteristic that the different movement profile types differ in the zero-crossing moment. Hence, using the determined zero-crossing moment and pre-stored information about possible movement profile types, the movement profile type can be determined without the necessity of any input from a user or operator.
In an embodiment, determining the configuration of the drive mechanism comprises determining a crossing moment, wherein a reversal point moment in the weaving cycle, when the moving element is in one of its reversal points, is determined based on the determined target detecting moments, and the crossing moment is defined based on the reversal point moment.
As defined above, the crossing moment is the moment in the weaving cycle, in which the moving element is in a position where the moving element should cross itself when moving from the upper position to the lower position or from the lower position to the upper position. In an embodiment, the reversal point moment is defined using a selected first determined target detecting moment determined for one target of the target set when driving the drive mechanism in the weaving direction and a selected second determined target detecting moment determined for said one target of the target set when driving the drive mechanism in the reverse direction, wherein the reversal point moment is the midpoint between the selected first determined target detecting moment and the selected second determined target detecting moment. In other embodiments, more than two determined target detecting moments are used to allow for a compensation of measurement inaccuracies.
In an embodiment, determining the configuration of the drive mechanism comprises determining a crossing height at the crossing moment relative to the zero position based on the movement profile type. In one embodiment, the movement profile type is determined based on the zero-crossing moment, which is determined based on the determined middle target detecting moment. In other embodiments, the movement profile type is known in advance or entered by a user or operator.
In an embodiment, determining the configuration of the drive mechanism further comprises determining a stroke of the heald frame, wherein the stroke is determined via a first way based on the upper target detecting moment and the lower target detecting moment, and wherein the stroke is determined via another way, which another way is selected out of a group comprising a second way based on the upper target detecting moment and the middle target detecting moment, a third way based on the middle target detecting moment and the lower target detecting moment, and a fourth way based on distances, in particular notches, between the upper target and the middle target and the middle target and the lower target.
As described in EP3341509A1 , an angular difference between two determined target detecting moments can be used for determining the stroke of the moving element, and thus the stroke of the heald frame driven by the moving element. For this purpose, in one embodiment, for a first way an angular distance between a movement of midpoints of the upper target and the lower target past the sensor element is determined. For said another way, in embodiments, the moments, when midpoints of the middle target are moved past the sensor element, are used. According to the fourth way, midpoints of the distance between the targets, in particular midpoints of notches between targets in the form of protrusions are used for a determination of the stroke.
In an embodiment, the stroke is determined using an assumed movement profile type selected out of a plurality of pre-stored movement profile types. In case an advance information is available about the movement profile type, a determination of the stroke is possible using two target detecting moments as described in EP3341509A1 . The invention allows a determination of the stroke without such an advance information of the movement profile type. For this purpose, it is assumed that the configuration has an assumed movement profile type selected out of a plurality of possible movement profile types, next the stroke is determined in at least two different ways in using the assumed movement profile. In case the same stroke within limits is determined using the two different ways, it is concluded that the assumed movement profile type is the actual movement profile type, and that the determined stroke is the actual stroke. If the strokes determined in two different ways differ, it is concluded that the assumed movement profile type is not the actual movement profile type. Hence, an alternative movement profile type is selected out of the plurality of possible movement profile types, and the determination is repeated. In this way, the stroke and the movement profile type can be determined without advance information about the actual movement profile type.
In an embodiment, a distance between the upper target and the middle target differs from a distance between the middle target and the lower target, wherein the method comprises determining a movement direction of the moving element based on a first angular distance between a first moment when detecting a first target of the target set and a second moment when detecting a second target of the target set and a second angular distance between the second moment when detecting a second target of the target set and a third moment when detecting a third target of the target set.
In an embodiment, determining the configuration of the drive mechanism comprises determining a binding pattern, wherein the drive mechanism is operated over a number of weaving cycles to move the moving element back-and-forth.
For a determination of the binding pattern, in an embodiment, it is determined based on determined target detecting moments, when the moving element is moved to drive the heald frame into a first extreme position and for how many weaving cycles the heald frame is maintained in the first extreme position, and when the moving element is moved to drive the heald frame into the second extreme position and for how many weaving cycles the heald frame is maintained in the second extreme position. In one embodiment, for this determination, the determined movement direction of the heald frame is used. The number of weaving cycles is determined based on a maximum number of weaving cycles for possible binding patterns. In one embodiment, e.g. for a cam mechanism wherein the number of weaving cycles for a binding pattern can be four, five or six weaving cycles, thus wherein the maximum number of weaving cycles for a binding pattern is six weaving cycles, the configuration can be determined when the target set passes the sensor element eleven times.
In an embodiment, a height detector is provided comprising a height detector target provided on a heald frame driven by the moving element and a height detector sensor element, wherein a height detector passing moment of the heald frame is detected, i.e. a moment in which the height detector target passes the height detector sensor element, and a height position of the heald frame is determined based on the height detector passing moment and a configuration of the drive mechanism, in particular the determined configuration of the drive mechanism using the above mentioned method, in particular using an assumed movement profile type selected out of a plurality of pre-stored movement profile types. The heald frame driven by the moving element may be coupled at different heights to the moving element, wherein in the context of the application, the relative position of heald frame with respect to the drive mechanism is referred to as height position of the heald frame.
According to a second aspect, a moving element of a drive mechanism for driving a heald frame of a weaving machine comprising a target set with an upper target and a lower target is provided, wherein the target set further comprises a middle target, wherein the middle target is arranged between the upper target and the lower target, wherein in particular the targets are protrusions provided at the moving element, in particular at a side end of the moving element, which protrusions are separated by notches. The moving element in preferred embodiments is a lever, in particular a lever arranged at a non-driven side of the drive mechanism. A lever having protrusions in an embodiment is manufactured by punching. In embodiments, the lever according to the invention replaces levers of existing drive mechanisms to allow the inventive method to be carried out.
According to a third aspect, a system comprising a control device, a drive mechanism for driving a heald frame of a weaving machine, the drive mechanism having a moving element, and a sensor device with a target set provided on the moving element and with a sensor element mountable stationary on the weaving machine and configured for detecting a presence of targets of the target set within a sensing range, is provided wherein the target set comprises an upper target, a middle target, and a lower target, wherein the middle target is arranged between the upper target and the lower target, wherein the drive mechanism is configured for being operated to move the moving element so that the target set passes the sensor element, wherein the control device is configured for determining an upper target detecting moment in a weaving cycle upon detecting the upper target, a middle target detecting moment in the weaving cycle upon detecting the middle target, and a lower target detecting moment in a weaving cycle upon detecting the lower target, and wherein the control device is configured for determining a configuration of the drive mechanism based on the upper target detecting moment, the middle target detecting moment, and the lower target detecting moment.
The system using a target set with three targets allows a determination of the configuration of the drive mechanism without advance information about certain configuration parameters, for example a movement profile type. Of course, the system can also be used in case at least some of the configuration parameters are known in advance and/or to check if the configuration parameters present or entered into the control unit of the weaving machine are correct.
In an embodiment, the sensor element is a proximity sensor, wherein the targets are protrusions provided at the moving element, in particular at a side end of the moving element, which protrusions are separated by notches, wherein the sensor device is configured for detecting with the sensor element rising edges of the targets when moving the targets into the sensing range.
In an embodiment, the system has a height detector configured for detecting a height detector passing moment of a heald frame and for determining a height position of the heald frame based on the height detector passing moment and the determined configuration of the drive mechanism, in particular using an assumed movement profile type selected out of a plurality of pre-stored movement profile types, wherein in particular the height detector comprises a height detector sensor element and a height detector target provided on a heald frame driven by the moving element of the drive mechanism.
Detecting a height detector passing moment of a heald frame and determining a height position of the heald frame based on the height detector passing moment does not necessarily require that a configuration of the drive mechanism is determined using a sensor device with three targets in accordance with claim 1. In an advantageous modification, a height position of the heald frame is determined based on a detected height detector passing moment and a known configuration of a drive mechanism driving the heald frame, in particular based on a known movement profile, a known zero-crossing line and/or a known zero-crossing moment. In another advantageous modification, a height position of the heald frame is determined based on a detected height detector passing moment and a determined configuration of a drive mechanism driving the heald frame, in particular a determined movement profile, a determined zero-crossing line and/or a determined zero-crossing moment, wherein in an embodiment the configuration is determined using a sensor device with only one target or with only two targets or with more than three targets.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, embodiments of the invention will be described in detail with reference to the drawings. Throughout the drawings, the same elements will be denoted by the same reference numerals.

Fig. 1: shows in a front view an embodiment of a drive mechanism for driving a heald frame of a weaving machine with a system for determining a configuration of the drive mechanism.
Fig. 2: shows a detail of the drive mechanism of Fig. 1 in enlarged scale.
Fig. 3: shows a detail of Fig. 2 in enlarged scale.
Fig. 4: shows in a front view the drive mechanism according to Fig. 1 with an alternative system for determining the configuration of the drive mechanism.
Fig. 5: shows a possible movement profile of a moving element of the drive mechanism of Fig. 1 over two weaving cycles.
Fig. 6: shows two movement profiles of two different movement profile types over three weaving cycles.
Fig. 7: shows four different movement profiles of four different movement profile types over two weaving cycles.
Fig. 8: shows a movement profile of a moving element for illustrating a stroke determination via a first way.
Fig. 9: shows the movement profile of Fig. 8 for illustrating a stroke determination via a second way or a third way.
Fig. 10: shows the movement profile of Fig. 8 for illustrating a stroke determination via a fourth way.
Fig. 11: shows three different movement profiles of one asymmetrical movement profile type for three different strokes and associated crossing heights.
Fig. 12: shows a movement profile of a heald frame and a movement profile of a moving element driving the heald frame for illustrating a determination of a height position of a heald frame using a height detector.
Fig. 13: shows a movement profile of a heald frame and a movement profile of a moving element driving the heald frame for illustrating a determination of a height position of a heald frame using a height detector via another way.
Fig. 14: shows a movement profile of a moving element for a binding pattern over six weaving cycles during twelve weaving cycles.

DETAILED DESCRIPTION OF EMBODIMENTS

Fig. 1 shows a heald frame 1 and a drive mechanism 2 of a shed-forming device 3 of a weaving machine. Fig. 2 shows a detail of the drive mechanism of Fig. 1 in enlarged scale, while Fig. 3 shows a detail of Fig. 2 in enlarged scale.
The shed-forming device 3 comprises a number of heald frames 1, wherein one drive mechanism 2 is assigned to each heald frame 1. In the embodiment shown, the number of drive mechanisms 2 are driven by a common drive system 26 with an axis 4. A stationary frame 9 of the weaving machine is schematically shown in Fig. 1.
The drive mechanism 2 for driving the heald frame 1 shown in Fig. 1 is a cam mechanism. It comprises two cams 5, 6 rotating about the axis 4, a drive lever 7 driven by the cams 5, 6 to oscillate about an axis 8, a coupling rod 10 coupled to the drive lever 7 via a hinged joint 11, and a first lever 12. The first lever 12 is swivelable to-and-fro about a stationary arranged first swivel axis 13 between an upper position and a lower position. The first lever 12 has a first arm 14 and a second arm 15, and the first lever 12 is coupled to the coupling rod 10 at the first arm 14. The drive mechanism 2 further comprises a second lever 16, that is swivelable to-and-fro about a second swivel axis 18 between an upper position and a lower position, and a third lever 17, that is swivelable to-and-fro about a third swivel axis 19 between an upper position and a lower position. The second lever 16 and the third lever 17 are linked to the first arm 14 of the first lever 12 by means of a connecting rod 20 and driven by the first lever 12 to conjointly move with the first lever 12. The first lever 12, the second lever 16 and the third lever 17 are conjointly referred to as levers 12, 16, 17. As will be understood by the person skilled in the art, other embodiments are conceivable, wherein only two of the levers 12, 16, 17 or more than three levers 12, 16, 17 are provided.
The heald frame 1 is linked to the second arm 15 of the first lever 12 by means of a lifting rod 21 and a fixation element 22 that is guided in a stationary guide element 23 of the weaving machine.
The second lever 16 and the third lever 17 are also linked via a lifting rod 21 and a fixation element 22 to the heald frame 1.
For determining a configuration of the drive mechanism 2, a sensor device 40 comprising a target set 41 and a sensor element 42 arranged stationary on the weaving machine are provided. As best seen in Fig. 2, the sensor device 40 comprises a target set 41 with an upper target 43, a middle target 44, and a lower target 45, which in the embodiment shown are provided on the third lever 17. The sensor element 42 is configured for detecting a presence of the targets 43, 44, 45 of the target set 41 within a sensing range of the sensor element 42.
In the embodiment shown in Fig. 1, in addition a height detector 50 is provided, which comprises a height detector target 51 provided on the heald frame 1 and a height detector sensor element 52 arranged stationary on the weaving machine, wherein the height detector sensor element 52 is configured for detecting a presence of the height detector target 51 within a sensing range of the height detector sensor element 52.
The sensor device 40 and the height detector 50, in particular the sensor element 42 of the sensor device 40 and the height detector sensor element 52 of the height detector 50 are both communicated to a control device 25, which control device 25 is for example part of a central control unit of the weaving machine or communicates with the central control unit of the weaving machine.
In the embodiment shown, the targets 43, 44, 45 of the target set 41 are protrusions provided on the lever 17, which lever 17 is arranged at a non-driven side of the drive mechanism 2, i.e. a side opposite to the drive lever 7. The targets 43, 44, 45 are provided in the form of protrusions protruding from a side end of the lever 17 facing away from the drive lever 7. This arrangement allows for sufficient mounting space for the target set 41 and the sensor element 42. However, the invention is not limited to this arrangement and other arrangements are conceivable to the person skilled in the art, for example the targets 43, 44, 45 of the target set 41 can be protrusions that are provided on the lever 12 or on the lever 16.
The first lever 12 is coupled to the drive lever 7 via the coupling rod 10. In the embodiment shown, the drive lever 7 is curved and the location of the hinged joint 11 connecting the connecting rod 10 to the drive lever 7 is adjustable along the drive lever 7 by sliding the hinged joint 11 along the drive lever 7. A curvature of the drive lever 7 is chosen so that upon adjusting the location of the hinged joint 11 along the drive lever 7, the hinged joint 11 remains situated on an arc of an imaginary circle schematically shown by a dashed-dotted line in Fig. 1 having its center at the connecting point between the first arm 14 and the coupling rod 10 and a radius as schematically indicated by an arrow 29 in Fig. 1. Therefore, in the embodiment shown, when adjusting the location of the hinged joint 11 along the drive lever 7 for adjusting a stroke of the heald frame 1, a zero position of the levers 12, 16, 17 as shown in Fig. 1 remains unchanged, wherein for example the zero position is a position in the middle of the travelled distance of the levers 12, 16, 17 with the same distance to both extreme positions. A line through the third swivel axis 19 when the lever 17 is in the zero position is referred to as zero position line 46, wherein as shown in Fig. 2 the zero position line 46 is a horizontal line through the swivel axis 19 of the lever 17 and the swivel axis 24 connecting the lever 17 and the lifting rod 21 for the heald frame 1.
As best seen in Figs. 2 and 3, in the embodiment shown, the sensor element 42 is arranged for example at a height of the zero position line 46 and the middle target 44 is arranged symmetrically or approximately symmetrically to the zero position line 46 when the lever 17 is in the zero position. Further, in the embodiment shown, a distance between the upper target 43 and the middle target 44, i.e. a size of a notch 30 provided between the upper target 43 and the middle target 44, differs from a distance between the middle target 44 and the lower target 45, i.e. a size of a notch 31 provided between the middle target 44 and the lower target 45. The upper target 43 is arranged symmetrically to a central line 27 through the third swivel axis 19, while the lower target 45 is arranged symmetrically to a central line 28 through the third swivel axis 19. In the embodiment shown, the upper target 43 and the lower target 45 differ in size, wherein as shown in Fig. 2 the zero position line 46 is for example arranged in the bisector of both central lines 27, 28. As in the embodiment shown, the upper target 43 and the lower target 45 differ in size, also the notches 30, 31 differ in size.
In operation, the heald frame 1 is driven to move up and down, wherein a movement profile of the drive mechanism 2 and, thus the heald frame 1 coupled thereto, depends inter alia on a configuration of the drive mechanism 2. As described above, a stroke of the heald frame 1 is settable by adjusting a location of the hinged joint 11 along the drive lever 7. Depending on the type of drive mechanism 2 additional or other elements are adjustable either in use or upon set-up or manufacturing of the drive mechanism 2. The weaving machine allows for setting and determining configuration parameters of a movement profile of the drive mechanism 2 selected of the group comprising a stroke, a zero-crossing moment, a crossing height, a crossing moment, a movement profile type and/or a binding pattern.
The first lever 12, the second lever 16, the third lever 17, the connecting rod 20, the lifting rods 21 and the fixation elements 22 are conjointly referred to as moving elements. In the embodiment shown in Figs. 1 and 2, the target set 41 is provided on the third lever 17 arranged at the non-driven side of the drive mechanism 2.
Fig. 4 shows the shed-forming device 3 together with another embodiment of the sensor device 40 for determining a configuration of the drive mechanism 2, wherein in contrast to the embodiment of Fig. 1 the target set 41 is provided on a different moving element, in particular on the connecting rod 20. The sensor element 42 is arranged opposite the target set 41. The target set 41 comprises three targets 43, 44, 45, which are all arranged at the same height. Despite their arrangement, the targets are referred to as upper target 43, middle target 44 and lower target 45 in conformity with a movement of the heald frame 1 driven by the drive mechanism 2. As shown in Fig. 4, the sensor device 40 and the height detector 50 are both communicated to a control device 25.
Fig. 5 shows a possible movement profile 70 of a moving element, in particular the third lever 17 of the drive mechanism 2 (see Fig. 1) over two weaving cycles, wherein in a first weaving cycle the moving elements 12, 16, 17, 20, 21, 22 and thus the heald frame 1 (see Fig. 1) are moved from a lower extreme position towards an upper extreme position and in a second weaving cycle the moving elements 12, 16, 17, 20, 21, 22 and thus the heald frame 1 are moved back into the lower extreme position. A zero-crossing line 53 for the moving element when the moving element is in the zero position is shown by a dashed-dotted line.
When moving from the lower extreme position towards the upper extreme position, the upper target 43, the middle target 44, and the lower target 45 (see Figs. 1 and 2) are moved one after the other past the sensor element 42 (see Figs. 1 and 2). Likewise, when moving from the upper extreme position towards the lower extreme position, the lower target 45, the middle target 44, and the upper target 43 are moved one after the other past the sensor element 42.
The presence of the targets 43, 44, 45 within the sensing range of the sensor element 42 when passing the sensor element 42 from below and from above is detectable, and target detecting moments can be determined.
In the embodiment shown, the sensor element 42 is configured to detect rising edges of the targets 43, 44, 45 when moving the targets 43, 44, 45 into the sensing range, so that when operating the drive mechanism 2 to move the lever 17 back-and-forth with the movement profile of Fig. 5, six target detecting moments can be detected, namely a first upper target detecting moment 1.43 in the weaving cycle upon detecting the upper target 43 when passing the sensor element 42 from below, a second upper target detecting moment 2.43 in the weaving cycle upon detecting the upper target 43 when passing the sensor element 42 from above, a first middle target detecting moment 1.44 in the weaving cycle upon detecting the middle target 44 when passing the sensor element 42 from below, a second middle target detecting moment 2.44 in the weaving cycle upon detecting the middle target 44 when passing the sensor element 42 from above, a first lower target detecting moment 1.45 in the weaving cycle upon detecting the lower target 45 when passing the sensor element 42 from below, and a second lower target detecting moment 2.45 in the weaving cycle upon detecting the lower target 45 when passing the sensor element 42 from above.
In the embodiment shown, the drive mechanism 2 is further operable in a reverse direction, wherein the lever 17 is moved with the same movement profile. When operating the drive mechanism 2 to move the lever 17 in a reverse direction back-and-forth with the movement profile of Fig. 5, again six target detecting moments can be detected, namely a third upper target detecting moment 3.43 in the weaving cycle upon detecting the upper target 43 when passing the sensor element 42 from below, a fourth upper target detecting moment 4.43 in the weaving cycle upon detecting the upper target 43 when passing the sensor element 42 from above, a third middle target detecting moment 3.44 in the weaving cycle upon detecting the middle target 44 when passing the sensor element 42 from below, a fourth middle target detecting moment 4.44 in the weaving cycle upon detecting the middle target 44 when passing the sensor element 42 from above, a third lower target detecting moment 3.45 in the weaving cycle upon detecting the lower target 45 when passing the sensor element 42 from below, and a fourth lower target detecting moment 4.45 in the weaving cycle upon detecting the lower target 45 when passing the sensor element 42 from above. Determining the third and fourth target detecting moments allows to reduce or even eliminate detection inaccuracies due to an upward or a downward movement of a heald frame 1 by the moving element 12, 16, 17, 20, 21, 22 over one revolution of the weaving machine.
Based on the target detecting moments shown in Fig. 5, an unknown configuration of the drive mechanism 2 can be determined as will be explained with reference to the following drawings.

Zero-Crossing Moment

In one embodiment, a zero-crossing moment 48 (shown by a dashed line in Fig. 5) in the weaving cycle is determined, i.e. a moment in the weaving cycle, when the moving element 12, 16, 17, 20, 21, 22 is in the position in the middle of the stroke or travel distance of the moving element (referred to as zero position).
Such a determination in one embodiment is made based on determined middle target detecting moments 1.44, 2.44, 3.44, 4.44.
As described for Fig. 2, in the embodiment shown, the middle target 44 is arranged symmetrically to a zero position line 46 when the moving element is in a zero position and the sensor element 42 is arranged at a height of the zero position line 46. In this case, a zero-crossing line 53 and, thus, zero-crossing moments 48, 54 can be determined based on two middle target detecting moments determined when the middle target 44 is moving past the sensor element 42 from above and from below, in particular the zero-crossing line 53 can be determined based on the first middle target detecting moment 1.44 and the second middle target detecting moment 2.44 or based on the third middle target detecting moment 3.44 and the fourth middle target detecting moment 4.44, while a first zero-crossing moment 48 can be determined based on the first middle target detecting moment 1.44 and the fourth middle target detecting moment 4.44 and a second zero-crossing moment 54 can be determined based on the third middle target detecting moment 3.44 and the second middle target detecting moment 2.44.

Crossing Moment

In the context of the application, the crossing moment is defined as the moment when the moving element 12, 16, 17, 20, 21, 22, in particular the lever 17, is in a position in relation to an angle of the weaving machine, in which the moving element 12, 16, 17, 20, 21, 22 should cross itself when moving from up to down or from down to up.
Fig. 6 shows two movement profiles of two different movement profile types over three weaving cycles, wherein a movement profile 70 of a first movement profile type, which is a symmetrical movement, is shown in a solid line, and a movement profile 71 of second movement profile type, which is an asymmetrical movement, is shown in a dashed line.
A zero-crossing line 53 is shown as a solid line. The zero-crossing line 53 is either known or determined using the above described method. Crossing moments 49 are shown by solid lines, wherein the crossing moments 49 are to be determined.
For a determination of the crossing moment 49, a reversal point moment 47 in the weaving cycle (shown in Fig. 5 and 6) is determined, wherein the reversal point moment 47 is defined as the moment, when the moving element is in one of its extreme positions and the movement is reversed. The reversal point moment 47 is deemed to be half of a weaving cycle, i.e. 180°, shifted from the crossing moment. Hence, based on the determined reversal point moment 47, the crossing moment 49 can be determined. The reversal point moment 47 can be determined as an average middle line between the target detection moments 1.43 and 3.43, the target detection moments 4.43 and 2.43, the target detection moments 1.44 and 3.44, the target detection moments 4.44 and 2.44, the target detection moments 1.45 and 3.45, and the target detection moments 4.45 and 2.45.
The movement profile type of the movement profile 70 shown in a solid in Fig. 6 is a symmetrical movement profile. Hence, the crossing moment 49 coincides with the zero-crossing moment 48 (shown by the dashed line in Fig. 5). The movement profile type of the movement profile 71 shown in a dashed line in Fig. 6 is an asymmetrical movement profile. Hence, the crossing moment 49 does not coincide with the zero-crossing moments 55, 56 (shown by the dashed-dotted line in Fig. 6) for the asymmetrical movement profile 71.
A position of the moving element 12, 16, 17, 20, 21, 22, in particular the lever 17, at the crossing moment is referred to as crossing position. A distance between the zero position and the crossing position is referred to as a crossing height H1. The movement profile type of the movement profile 70 shown in Fig. 6 is a symmetrical movement profile and the zero position coincides with the crossing position. The movement profile type of the movement profile 71 shown in Fig. 6 is an asymmetrical movement profile and the distance between the zero position and the crossing position is the crossing height H1, in particular the distance between the zero-crossing line 53 and the crossing line 58.

Movement Profile Type and Stroke Determination

In the context of the application, different movement profiles defined by a configuration of a drive mechanism are referred to as movement profile types, wherein the movement profile types can be symmetrical movements or asymmetrical movements. When using an asymmetrical movement profile, typically the movement profile is different for the lower warp threads than for the upper warp threads.
In an embodiment of the invention, a movement profile type is determined.
A determination of a movement profile type in one embodiment is used for a determination of a configuration of the drive mechanism 2 in the form of a cam mechanism as shown in Fig. 1, wherein a profile of the cams 5, 6 and/or an angular offset of the cams 5, 6 in relation to a main shaft of a weaving machine is not known in advance.
As shown in Fig. 6, for a symmetrical movement profile 70 shown by the solid line, the zero position, i.e. a position of the moving element 12, 16, 17, 20, 21, 22, in particular the lever 17, half-way between the extreme positions, coincides with the crossing position, i.e. a position of the moving element 12, 16, 17, 20, 21, 22, in particular the lever 17, at the crossing moment 49, in which the moving element 12, 16, 17, 20, 21, 22 should cross itself when moving from up to down or from down to up. As indicated by double arrows, in the embodiment of Fig. 6, the distance A1 is equal to the distance A2.
For an asymmetrical movement profile 71 shown by the dashed line, the zero position i.e. a position of the moving element 12, 16, 17, 20, 21, 22, in particular the lever 17, half-way between the extreme positions at the zero-crossing moment 48 of the asymmetrical movement profile 71, is offset to the crossing position, i.e. the crossing position is closer to one of the extreme positions. As indicated by double arrows, in the embodiment shown in Fig. 6, the crossing position is closer to a lower extreme position, in other words the distance B1 is less than the distance B2.
Hence, based on the information that the crossing position does or does not coincide with the zero position, a symmetrical movement can be distinguished from an asymmetrical movement.
In an embodiment, based on the determined information whether the movement profile type is a symmetrical movement or an asymmetrical movement, and pre-stored knowledge about the drive mechanism 2, and thus pre-stored knowledge about possible movement profile types when using the drive mechanism 2, the actual movement profile type can be determined without the necessity of any input from a user or an operator.
For example, in the drive mechanism 2 shown in Fig. 1 different cam sets and cam set arrangements can be used allowing for the two symmetrical movement profiles 70, 72 and the two asymmetrical movement profiles 71, 73 as shown in Fig. 7 over two weaving cycles. A zero-crossing line 53 is shown as a solid line.
As shown in Fig. 7, the two symmetrical movement profiles 70, 72 both have a crossing position at the zero position.
The asymmetrical movement profiles 71, 73 differ in an angular distance or shift between a crossing moment 49 and their respective zero-crossing moment 55 or 57. Hence, based on the determined zero-crossing moment 55 or 57 in relation to the determined crossing moment 49 and the pre-stored information about the asymmetrical movement profile types, it is possible to determine for the two asymmetrical movement profiles 71, 73 a cam configuration of the drive mechanism 2, and thus, the associated movement profile type.
As shown in Fig. 7, the symmetrical movement profiles 70, 72 all have the same crossing moment 49, which is the zero-crossing moment.
In order to identify the actual symmetrical movement profile type, in one embodiment, a stroke is determined via at least two different ways for each possible symmetrical movement profile type, and the actual symmetrical movement profile type is determined as the symmetrical movement profile type for which the stroke determined via the at least two different ways is identical or shows the least deviation.
Fig. 8 shows a movement profile 70 of a moving element for illustrating a stroke determination via a first way, wherein the stroke is determined based on an upper target detecting moment 63 and a lower target detecting moment 65. More particular, the stroke is determined based on the angular distance D1 between the upper target detecting moment 63 and the lower target detecting moment 65 for each possible movement profile type, for example for the two symmetrical movement profile types. The determination can be carried out as described in EP3341509 , the content of which is hereby incorporated by reference.
In the embodiment shown, the upper target detecting moment 63 is determined based on at least two of the first, second, third or fourth upper target detecting moments 1.43, 2.43, 3.43, 4.43 associated with two different edges of the upper target 43 (see Fig. 2), in particular is determined in the example based on the upper target detecting moments 1.43 and 4.43. The lower target detecting moment 65 is determined based on at least two of the first, second, third or fourth lower target detecting moments 1.45, 2.45, 3.45, 4.45 associated with two different edges of the lower target 45 (see Fig. 2), in particular is determined in the example based on the lower target detecting moments 1.45 and 4.45. In the alternative, one of the first, second, third or fourth upper target detecting moments 1.43, 2.43, 3.43, 4.43 is used as the upper target detecting moment and one of the first, second, third or fourth lower target detecting moments 1.45, 2.45, 3.45, 4.45 is used as the lower target detecting moment.
Fig. 9 shows the movement profile 70 of Fig. 8 for illustrating a stroke determination via a second way or a third way, wherein the stroke is determined via the second way based on the upper target detecting moment 63 and a middle target detecting moment 64 and/or via the third way based on the middle target detecting moment 64 and the lower target detecting moment 65. The stroke is then determined based on the angular distance D2 between the upper target detecting moment 63 and the middle target detecting moment 64 or based on the angular distance D3 between the middle target detecting moment 64 and the lower target detecting moment 65.
In the embodiment shown, the middle target detecting moment 64 is determined based on at least two of the first, second, third or fourth middle target detecting moments 1.44, 2.44, 3.44, 4.44 associated with two different edges of the middle target 44 (see Fig. 2), in particular is determined in the example based on the middle target detecting moments 1.44 and 4.44.
By providing a sensor device 40 with a target set 41 having three targets 43, 44, 45, the angular distances D1, D2 or D3 between at least two different pairs of targets 43, 44, 45 can be determined and the stroke can be determined based on these angular distances for each possible movement profile type, in particular for each possible symmetrical movement profile type. The symmetrical movement profile type for which the stroke determined using the angular distances between at least two different pairs of targets 43, 44, 45 via the at least two different ways that is identical or shows the least deviation between the different ways, is identified as the actual symmetrical movement profile type.
Fig. 10 shows the movement profile 70 of Fig. 8 for illustrating a stroke determination via a fourth way, wherein the stroke is determined based on the angular distance D4. In the embodiment shown, the angular distance D4 is determined based on the notch 30 (see Fig. 2) between the upper target 43 and the middle target 44 and the notch 31 (see Fig. 2) between the middle target 44 and the lower target 45. As shown in the example of Fig. 10, the center 61 of the notch 30 can be determined based on the distance between the fourth upper target detecting moment 4.43 and the first middle target detecting moment 1.44, while the center 62 of the notch 31 can be determined based on the distance between the fourth middle target detecting moment 4.44 and the first lower target detecting moment 1.45. The angular distance D4 can be determined as the distance between the center 61 and the center 62. In an alternative, the center 61 can be determined based on the distance between second upper target detecting moment 2.43 and the third middle target detecting moment 3.44, while the center 62 can be determined based on the distance between the second middle target detecting moment 2.44 and the third lower target detecting moment 3.45.
Hence, by providing a sensor device 40 with a target set 41 having three targets 43, 44, 45, in alternative or in addition to the ways for determining the stroke described above, the angular distance between notches 30, 31 or other distances between the targets can be determined and the stroke can be determined based on this angular distance for each possible movement profile type.
As mentioned above, asymmetrical movement profile types can be determined directly based on the angular distance or shift between a crossing moment 49 and a zero-crossing moment 55, 57. Of course it is also possible to determine the stroke for an asymmetrical movement profile in a way as described above for a symmetrical movement profile, for example in case both asymmetrical movement profiles have a same zero-crossing moment. If the movement profile type is known, it is sufficient to determine the stroke using only one of the four ways described above. In an embodiment, the first way is used for the determination of the stroke as the angular distance between the upper target and the lower target is larger than any other angular distance determined, and the stroke determination is more accurate. However, in other embodiments, the stroke is determined for the asymmetrical movement profile types via another way than the first way or via more than one way.

Crossing height

As mentioned above, for asymmetrical movement profile types the crossing position is offset from a zero position. The crossing position depends on the asymmetrical movement profile type and the stroke.
Fig. 11 shows three different movement profiles 71, 74, 75 of one asymmetrical movement profile type for three different strokes. If the movement profile type and the crossing moments are known, a crossing height H 1, H2, H3 of the movement profile 71, 74, 75 can be determined, i.e. a distance between the zero position indicated by the zero-crossing line 53 and the crossing position at the crossing moment 49 indicated by the crossing lines 58, 59, 60.
The determined crossing height H1, H2, H3 in one embodiment can be used to optimize a height position of the heald frame 1, in other words a relative position of the heald frame 1 with respect to the levers 12, 16, 17.

Height position of the heald frame

In the embodiment shown in Figs. 1 and 4, the shed-forming device 3 further comprises a height detector 50 with a height detector target 51 provided on the heald frame 1 and a height detector sensor element 52 arranged stationary on the weaving machine.
Fig. 12 shows a movement profile 80 of the heald frame 1 and a movement profile 70 of a moving element, in particular the lever 17 (see Fig. 1), driving the heald frame 1 for illustrating a determination of a relative height position of the heald frame 1, also referred to as height position, using the height detector 50 (see Fig. 1). The movement profile 80 of the heald frame 1 follows the movement profile 70 of the moving element, because the heald frame 1 is driven by the moving element.
The movement profile 70 of the moving element can be determined as described above, wherein in particular a zero-crossing line 53 and a zero-crossing moment 48 are determined.
The height detector target 51 is for example a protrusion and the height detector sensor element 52 is configured for example to detect a rising edge of the height detector target 51 when the height detector target 51 is approaching the height detector sensor element 52 from above and from below.
Hence, driving the heald frame 1 with the drive mechanism 2 to move up and down in the weaving direction and in the reverse direction, similar as explained in Fig. 5, in the embodiment shown four height detector target detecting moments can be determined, namely a first height detector target detecting moment 1.51, a second height detector target detecting moment 2.51, a third height detector target detecting moment 3.51, and a fourth height detector target detecting moment 4.51 as illustrated in Fig. 12.
In the embodiment shown, in a standard height position the heald frame 1 is connected to the drive mechanism 2 such that a center of the height detector target 51 is arranged opposite the height detector sensor element 52, when the center of the middle target 44 is arranged opposite the sensor element 42. The movement profile 80 of the heald frame 1, when the heald frame 1 is set in the standard height position is shown in a solid line, is referred to as standard movement profile 80. For this standard movement profile 80, for example the zero-crossing moment 48 of the movement profile 70 coincides with the moment in which the height detector target 51 is opposite the height detector sensor element 52.
For setting the standard height position of the heald frame 1 the drive mechanism 2 can be arranged in a standard position, preferably the zero position, while the height target detector 51 and/or the height detector sensor element 52 are mutually shifted up and down until the height detector target 51 is arranged opposite the height detector sensor element 52. In this way, a zero-crossing line 82 of the standard movement profile 80 crosses the standard movement profile 80 at the standard zero-crossing height target detecting moment 76, which in the example coincides with the zero-crossing moment 48 of the movement profile 70. In this example, the zero-crossing moment 48 also coincides with the middle target detecting moment 64 of Fig. 9.
To this end the zero-crossing line 82 for the standard movement profile 80 can determined based on the first height detector target detecting moment 1.51, the second height detector target detecting moment 2.51, the third height detector target detecting moment 3.51 and/or the fourth height detector target detecting moment 4.51, for example is determined based on the first height detector target detecting moment 1.51 and the fourth height detector target detecting moment 4.51.
When attaching the heald frame 1 in a different height position to the drive mechanism 2, a movement profile 81 of the heald frame 1 is shifted in position. The height position of the heald frame 1 relative to the drive mechanism 2 can for example be changed by changing the distance between the levers 12, 16, 17 and the heald frame 1, such as described in EP520540A1 . Of course, other height position setting devices can be used, for example as described in EP2619361 or in EP1322805B1 .
Fig. 12 shows in a dashed line a movement profile 81 of a heald frame 1 attached in a position above the standard height position to the drive mechanism 2. As shown in Fig. 12, in this case, the height detector target 51 passes the height detector sensor element 52 before the zero-crossing moment 48, i.e. the zero-crossing height target detecting moment 66 of the heald frame 1 is before the zero-crossing moment 48 of the moving element.
The movement profile 81 of the heald frame 1 follows the movement profile 70 of the moving element. Hence, based on the movement profile 70 of the moving element and an absolute height position of the heald frame 1 detected by the height detector 50, a relative position of the heald frame 1 with respect to a zero position of the moving element can be determined, in other words a relative height position of the heald frame 1 can be determined.
For the standard movement profile 80 representing the standard height position as explained above, the standard zero-crossing height target detecting moment 76 of the standard movement profile 80 coincides with is the zero-crossing moment 48 of the movement profile 70.
For a different movement profile 81 a first height detector target detecting moment 1.61, a second height detector target detecting moment 2.61, a third height detector target detecting moment 3.61 and/or a fourth height detector target detecting moment 4.61 can be determined and based on these height detector target detecting moments, the zero-crossing height target detecting moment 66 for the movement profile 81 can be determined, for example based on the first height detector target detecting moment 1.61 and the fourth height detector target detecting moment 4.61.
The angular distance D5 between the zero-crossing moment 48 and the zero-crossing height target detecting moment 66 determines a value that is in relation to, in particular is proportional to the relative height position of the heald frame 1, which for example can be determined by geometrical calculation based on the distance D5 and the determined movement profile. For the movement profile 81 with respect to the standard movement profile 80, the height position is indicated by an arrow H5 in Fig. 12. In Fig. 12 the arrow H5 points upwards, which means that the heald frame 1 is arranged further away from the drive mechanism 2 such that the height detector target 51 reaches the height detector sensor element 52 before the moving element reaches its zero position. Alternatively, if the heald frame 1 is arranged closer to the drive mechanism 2, the height detector target 51 will reach the height detector sensor element 52 after the moving element reaches its zero position, such that the associated arrow will point downwards.
Fig. 13 shows a determination of a height position of a heald frame 1 using a height detector 52 via another way. In this example, the zero-crossing moment 48 is determined based on the upper target detecting moment 63 and the lower target detecting moment 65. When using a sensor device 40 as shown in Fig. 3, wherein the zero position line 46 is arranged in the bisector of both central lines 27, 28, the zero-crossing moment 48 can be determined as the average of the upper target detecting moment 63 and the lower target detecting moment 65. The heald frame 1 can also be arranged in a height position such that the zero-crossing moment 48 coincides with the standard zero-crossing height target detecting moment 76 when the standard movement profile 80 crosses the zero-crossing line 82 of the standard movement profile 80. The relative height position of the heald frame 1 can further be determined as in the example of Fig. 12.
Both methods as described with reference to Figs. 12 and 13 in an embodiment are used in combination for determining the height position of the heald frame 1 in two alternative ways, thereby determining the height position more accurately, for example based on an average of the values obtained by the two alternative ways.
As will be understood by the person skilled in the art, detecting a height detector passing moment of a heald frame and determining a height position of the heald frame based on the height detector passing moment with any of the methods described above with reference to Fig. 12 and 13 does not necessarily require that a configuration of the drive mechanism is determined using a target set 41 having three targets 43, 44, 45 as shown in Fig. 3 and/or that a moving element of the drive mechanism is equipped with three targets.
Rather, in the exemplary method described with reference to Fig. 12, only target detection moments are used that are based on the middle target 44, while in the exemplary method described with reference to Fig. 13 only target detection moments are used that are based on the upper target 43 and the lower 45.
As will be understood by the person skilled in the art, the standard height position can also be determined using the method described with reference to Fig. 12 based on the upper target 43 or based on the lower target 45, instead of based on the middle target 44. Similarly, the standard height position can also be determined using the method described with reference to Fig. 13 based on the upper target 43 and the middle target 44, or based on the lower target 45 and the middle target 44, instead of based on the upper target 43 and the lower target 45.
In other words, the above in general discloses a method for determining a height position of the heald frame in relation to a standard height position based on the height detector passing moment, the zero-crossing line 53 and/or the zero-crossing moment 48, wherein the height detector passing moment is determined using the height detector 50 comprising the height detector sensor element 52 and the height detector target 51 provided on the heald frame 1, and wherein the zero-crossing line 53 and the zero-crossing moment 48 are determined using a sensor device with a sensor element and at least one target provided on a moving element of the drive mechanism, in particular exactly one target, two targets or three targets.
In an embodiment the height position of the heald frame 1 is determined in two alternative ways using a sensor device with a target set having two targets, wherein the height position is determined based on an average of the values obtained by the two alternative ways.

Binding Pattern

In the embodiments described above, a movement profile was determined having a 1:1 binding pattern, wherein in each weaving cycle the heald frame 1 is moved up or down. However, weaving with different binding patterns is well known.
Typically, in case the drive mechanism 2 is a dobby mechanism or a motor driven mechanism, the binding pattern is known to a control unit of the weaving machine and no determination is necessary.
However, for a drive mechanism in form of a cam mechanism, typically the binding pattern is not known to the control unit of the weaving machine and needs to be manually input by a user.
Therefore, in one embodiment, the determination of the configuration of the drive mechanism 2 in alternative or in addition comprises a determination of a binding pattern based on the data of the sensor device 40 having a target set 41 with three targets. Such a determination can also be used for verifying the correctness of a binding pattern, in case a dobby mechanism or a motor driven mechanism is used.
Fig. 14 shows a movement profile 70 of a moving element for a binding pattern over six weaving cycles, and shows the movement profile 70 over twelve weaving cycles.
In order to determine the binding pattern, in one embodiment, the drive mechanism 2 (see Fig. 1) is driven in a forward or weaving direction and a movement direction of the heald frame 1 and/or the moving element driving the heald frame 1 is determined. Such a determination in an embodiment is carried out based on determined target detecting moments 1.43, 2.43, 1.44, 2.44, 1.45, 2.45 when moving in a weaving direction (see Fig. 5).
The number of weaving cycles for the determination is chosen based on a maximum number of weaving cycles for possible binding patterns. In one embodiment, e.g. for a cam mechanism, wherein the maximum number of weaving cycles for a binding pattern is six weaving cycles, as described above the configuration can be determined when the target set passes the sensor element at least eleven times. This allow to determine the binding pattern irrespectively if the binding pattern has a number of weaving cycles less than six weaving cycles.
Based on the determined target detecting moments 1.43, 2.43, 1.44, 2.44, 1.45, 2.45 it can be determined, when the moving element, in particular the lever 17, is moved to drive the heald frame 1 into a first extreme position and for how many weaving cycles the heald frame 1 is maintained in the first extreme position, and when the moving element is moved to drive the heald frame 1 into the second extreme position and for how many weaving cycles the heald frame 1 is maintained in the second extreme position.
In one embodiment, for a determination of the binding pattern starting from an unknown initial position, a movement direction of the heald frame is determined.
For this purpose, in the embodiment shown in Fig. 2, a distance between the upper target 43 and the middle target 44 differs from a distance between the middle target 43 and the lower target 45. It should be noted that the difference in distance in the embodiment shown is achieved by providing targets 43, 45 of different length. In alternative or in addition, the difference in distance is achieved by providing notches 30, 31 of different length between the targets 43, 44, 45.
Due to the different distances, a movement direction of the lever 17 can be determined based on angular distances between determined target detecting moments 1.43, 2.43, 1.44, 2.44, 1.45, 2.45 and/or moments derived from said determined target detecting moments 1.43, 2.43, 1.44, 2.44, 1.45, 2.45. It should be noted that for this purpose it is not necessary to determine the exact values of the target detecting moments 1.43, 2.43, 1.44, 2.44, 1.45, 2.45, but a signal pattern can be sufficient.
In one embodiment, the determination of the movement direction is carried out by using only a subset of two targets of the target set.
In Fig. 5 the target detecting moments 1.43, 4.43, 1.44, 4.44, 1.45, 4.45, 2.43, 3.43, 2.44, 3.44, 2.45, 3.45 are determined during two weaving cycles. For a binding pattern as in Fig. 14 it is possible to determine the detecting moments 1.43, 4.43, 1.44, 4.44, 1.45, 4.45, 2.43, 3.43, 2.44, 3.44, 2.45, 3.45 during a number of different weaving cycles, for example over six weaving cycles, and to take an average value for the respective detecting moments 1.43, 4.43, 1.44, 4.44, 1.45, 4.45, 2.43, 3.43, 2.44, 3.44, 2.45, 3.45. For example, the detecting moments 1.43, 1.44, 1.45, 4.45, 4.44, 4.43 can be detected one time in the area 67, while the detecting moments 2.43, 2.44, 2.45, 3.45, 3.44, 3.43 can be detected one time in the area 68 and one time in the area 69, so that an average of these detecting moments can be determined as respective detecting moments. The embodiment of Fig. 5 can be seen as determining the respective detecting moments in the areas 67 and 69 of the binding pattern of Fig. 14.

Claims

Method for determining with a sensor device (40) a configuration of a drive mechanism (2) having a moving element (12, 16, 17, 20, 21, 22) for driving a heald frame (1) of a weaving machine, wherein the sensor device (40) comprises a target set (41) provided on the moving element (12, 16, 17, 20, 21, 22) of the drive mechanism (2) with an upper target (43) and a lower target (45), and the sensor device (40) comprises a sensor element (42) arranged stationary on the weaving machine and configured for detecting a presence of the targets (43, 45) of the target set (41) within a sensing range, wherein the method comprises operating the drive mechanism (2) to move the moving element (12, 16, 17, 20, 21, 22) so that the target set (41) passes the sensor element (42), detecting with the sensor element (42) the presence of the upper target (43) and the lower target (45) within the sensing range, and determining an upper target detecting moment (63) in a weaving cycle upon detecting the upper target (43) and determining a lower target detecting moment (65) in a weaving cycle upon detecting the lower target (45), characterized in that the method comprises detecting with the sensor element (42) the presence of a middle target (44) within the sensing range, wherein the middle target (44) is provided on the moving element (12, 16, 17, 20, 21, 22) of the drive mechanism (2) and arranged between the upper target (43) and the lower target (45), determining a middle target detecting moment (64) in the weaving cycle upon detecting the middle target (44), and determining a configuration of the drive mechanism (2) based on the upper target detecting moment (63), the middle target detecting moment (64), and the lower target detecting moment (65).
The method according to claim 1, characterized in that the sensor element (42) is a proximity sensor, wherein the targets (43, 44, 45) are protrusions provided at the moving element (12, 16, 17, 20, 21, 22), which protrusions are separated by notches, wherein the method comprises detecting with the sensor element (42) rising edges of the targets (43, 44, 45) when moving the targets (43, 44, 45) into the sensing range.
The method according to claim 1 or 2, characterized in that the drive mechanism (2) is operated in a weaving direction to move the moving element (12, 16, 17, 20, 21, 22) back-and-forth so that the target set (41) passes the sensor element (42) from below and from above, wherein the presence of the targets (43, 44, 45) within the sensing range is detected when passing the sensor element (42) from below and from above, and wherein target detecting moments are determined, which target detecting moments include a first upper target detecting moment (1.43) in the weaving cycle upon detecting the upper target (43) when passing the sensor element (42) from below, a second upper target detecting moment (2.43) in the weaving cycle upon detecting the upper target (43) when passing the sensor element (42) from above, a first middle target detecting moment (1.44) in the weaving cycle upon detecting the middle target (44) when passing the sensor element (42) from below, a second middle target detecting moment (2.44) in the weaving cycle upon detecting the middle target (44) when passing the sensor element (42) from above, a first lower target detecting moment (1.45) in the weaving cycle upon detecting the lower target (45) when passing the sensor element (42) from below, and a second lower target detecting moment (2.45) in the weaving cycle upon detecting the lower target (45) when passing the sensor element (42) from above.
The method according to claim 3, characterized in that the drive mechanism (2) is operated in a reverse direction to move the moving element (12, 16, 17, 20, 21, 22) back-and-forth so that the target set (41) passes the sensor element (42) from below and from above, wherein the presence of the targets (43, 44, 45) within the sensing range is detected when passing the sensor element (42) from below and from above, and wherein target detecting moments are determined, which target detecting moments include a third upper target detecting moment (3.43) in the weaving cycle upon detecting the upper target (43) when passing the sensor element (42) from below, a fourth upper target detecting moment (4.43) in the weaving cycle upon detecting the upper target (43) when passing the sensor element (42) from above, a third middle target detecting moment (3.44) in the weaving cycle upon detecting the middle target (44) when passing the sensor element (42) from below, a fourth middle target detecting moment (4.44) in the weaving cycle upon detecting the middle target (44) when passing the sensor element (42) from above, a third lower target detecting moment (3.45) in the weaving cycle upon detecting the lower target (45) when passing the sensor element (42) from below, and a fourth lower target detecting moment (4.45) in the weaving cycle upon detecting the lower target (45) when passing the sensor element (42) from above.
The method according to claim 3 or 4, characterized in that determining the configuration of the drive mechanism (2) comprises determining a zero-crossing moment (48) in the weaving cycle when the moving element (12, 16, 17, 20, 21, 22) is in a zero position based on two determined middle target detecting moments (64), which determined middle target detecting moments (64) have been determined upon detecting the middle target (44) when passing the sensor element (42) from above and from below, wherein in particular the middle target (44) is arranged symmetrically to a zero position line (46) when the moving element is in a zero position and the sensor element (42) is arranged at a height of the zero position line (46).
The method according to claim 5, characterized in that determining the configuration of the drive mechanism (2) comprises determining a movement profile type, wherein information about different movement profile types is pre-stored, and the movement profile type is determined based on the determined zero-crossing moment (48).
The method according to any one of claims 3 to 6, characterized in that determining the configuration of the drive mechanism (2) comprises determining a crossing moment (49), wherein a reversal point moment (47) in the weaving cycle, when the moving element (12, 16, 17, 20, 21, 22) is in one of its reversal points, is determined based on the determined target detecting moments, and the crossing moment (49) is defined based on the reversal point moment (47).
The method according to claim 7, characterized in that determining the configuration of the drive mechanism (2) comprises determining a crossing height (H1, H2, H3) at the crossing moment relative to the zero position based on the movement profile type.
The method according to any one of claims 1 to 8, characterized in that determining the configuration of the drive mechanism (2) comprises determining a stroke of the heald frame (1), wherein the stroke is determined via a first way based on the upper target detecting moment (63) and the lower target detecting moment (65), and wherein the stroke is determined via another way, which another way is selected out of a group comprising a second way based on the upper target detecting moment (63) and the middle target detecting moment (64), a third way based on the middle target detecting moment (64) and the lower target detecting moment (65), and a fourth way based on distances, in particular notches (30, 31), between the upper target (43) and the middle target (44) and the middle target (44) and the lower target (45).
The method according to claim 9, characterized in that the stroke is determined using an assumed movement profile type selected out of a plurality of pre-stored movement profile types.
The method according to any one of claims 1 to 10, characterized in that a distance between the upper target (43) and the middle target (44) differs from a distance between the middle target (44) and the lower target (45), wherein the method comprises determining a movement direction of the moving element (12, 16, 17, 20, 21, 22) based on a first angular distance between a first moment when detecting a first target of the target set (41) and a second moment when detecting a second target of the target set (41) and a second angular distance between the second moment when detecting a second target of the target set (41) and a third moment when detecting a third target of the target set (41).
The method according to any one of claims 1 to 11, characterized in that determining the configuration of the drive mechanism (2) comprises determining a binding pattern, wherein the drive mechanism (2) is operated over a number of weaving cycles to move the moving element (12, 16, 17, 20, 21, 22) back-and-forth.
The method according to any one of claims 1 to 12, characterized in that a height detector passing moment of the heald frame (1) is detected and a height position of the heald frame (1) is determined based on the height detector passing moment and the determined configuration of the drive mechanism (2), in particular using an assumed movement profile type selected out of a plurality of pre-stored movement profile types.
Moving element of a drive mechanism (2) for driving a heald frame (1) of a weaving machine comprising a target set (41) with an upper target (43) and a lower target (45), characterized in that the target set (41) comprises a middle target (44), wherein the middle target (44) is arranged between the upper target (43) and the lower target (45), wherein in particular the targets (43, 44, 45) are protrusions provided at the moving element (12, 16, 17, 20, 21, 22), in particular at a side end of the moving element (12, 16, 17, 20, 21, 22), which protrusions are separated by notches.
Moving element according to claim 14, characterized in that the moving element is a lever (17), in particular a lever (17) arranged at a non-driven side of the drive mechanism (2).
System comprising a control device (25), a drive mechanism (2) for driving a heald frame (1) of a weaving machine, the drive mechanism (2) having a moving element (12, 16, 17, 20, 21, 22), and a sensor device (40) with a target set (41) provided on the moving element (12, 16, 17, 20, 21, 22) and with a sensor element (42) mountable stationary on the weaving machine and configured for detecting a presence of targets (43, 44, 45) of the target set (41) within a sensing range, wherein the target set (41) comprises an upper target (43) and a lower target (45), wherein the drive mechanism (2) is configured for being operated to move the moving element (12, 16, 17, 20, 21, 22) so that the target set (41) passes the sensor element (42), wherein the control device (25) is configured for determining an upper target detecting moment (63) in a weaving cycle upon detecting the upper target (43) and a lower target detecting moment (65) in a weaving cycle upon detecting the lower target (45), characterized in that the target set (41) comprises a middle target (44), wherein the middle target (44) is arranged between the upper target (43) and the lower target (45), wherein the control device (25) is configured for determining a middle target detecting moment (64) in a weaving cycle upon detecting the middle target (44), and wherein the control device (25) is configured for determining a configuration of the drive mechanism (2) based on the upper target detecting moment (63), the middle target detecting moment (64), and the lower target detecting moment (65).
The system according to claim 16, characterized in that the sensor element (42) is a proximity sensor, wherein the targets are protrusions provided at the moving element (12, 16, 17, 20, 21, 22), in particular at a side end of the moving element (12, 16, 17, 20, 21, 22), which protrusions are separated by notches, wherein the sensor device (40) is configured for detecting with the sensor element (42) rising edges of the targets (43, 44, 45) when moving the targets (43, 44, 45) into the sensing range.
The system according to claim 16 or 17, characterized in that the system has a height detector (50) configured for detecting a height detector passing moment of a heald frame (1) and for determining a height position of the heald frame (1) based on the height detector passing moment and the determined configuration of the drive mechanism (2), in particular using an assumed movement profile type selected out of a plurality of pre-stored movement profile types, wherein in particular the height detector (50) comprises a height detector target (51) provided on a heald frame (1) driven by the moving element (12, 16, 17, 20, 21, 22) and a height detector sensor element (52).