Clamping of the position of the latitudinal parts of a fabric guiding device

Abstract

A fabric guiding device (1) for a weaving machine, having automatic clampers (6), (7) to release or secure a bridge, for example an upper bridge (2) and/or a lower bridge (3). On the other hand, a method for releasing and re-clamping a bridge of a fabric guiding device of a weaving machine. Preferably suitable for use in a weaving machine. More particularly, for use in a face-to-face weaving machine.

Claims

1. Fabric guiding device for a weaving machine, comprising an upper bridge and/or a lower bridge, wherein the device comprises first automatic clampers which are provided in order to release and secure the upper bridge and/or the lower bridge.

2. Fabric guiding device according to claim 1, characterized in that the device comprises at least a lower bridge and in that the device further comprises second automatic clampers which are provided in order to release and secure the lower bridge between its two ends.

3. Fabric guiding device according to claim 1, characterized in that the first and/or second clampers comprise hydraulic or electric actuators.

4. Fabric guiding device according to claim 1, characterized in that the first and/or second clampers are provided in order to connect the upper bridge or the lower bridge to the chassis of the weaving machine.

5. Fabric guiding device according to claim 1, characterized in that the device comprises a drive provided in order to position the upper bridge and/or the lower bridge .

6. Fabric guiding device according to claim 5, characterized in that the device comprises an upper bridge and a lower bridge and in that the device further comprises couplers which are switchable between a first position in which the upper bridge and the lower bridge are coupled to one another, as a result of which the upper bridge and the lower bridge are positionable together with the aid of said drive, and a second position in which the upper bridge and the lower bridge are decoupled from one another so that only the upper bridge or only the lower bridge is positionable with the aid of the drive.

7. Fabric guiding device according to claim 6, characterized in that the lower bridge is positionable in both the first and the second position of the couplers and in that said couplers are switchable between a first position in which the lower bridge and the upper bridge are coupled to one another, as a result of which they are positionable together, and a second position in which only the lower bridge is positionable.

8. Fabric guiding device according to claim 5, characterized in that the drive comprise hydraulic or electric actuators.

9. Fabric guiding device according to claim 5, characterized in that the drive comprise one or more screw mechanisms which are provided in order to position the upper bridge and/or the lower bridge with respect to one another or with respect to a fixed reference point in the weaving machine, and in that the drive comprises at least one electric motor which is provided in order to rotate the screw mechanisms for adjusting said bridges.

10. Fabric guiding device according to one of claim 6, characterized in that the drive comprises a first and second drive, wherein the first drive is provided at one end of the bridge which is positionable when the couplers are switched into their second position and in that the second drive is provided at the other end of said bridge.

11. Fabric guiding device according to claim 1, characterized in that the fabric guiding device comprises an upper bridge and a lower bridge and in that the device further comprises one or more position sensors (9) for determining the position of the upper bridge and the lower bridge .

12. Weaving machine provided with a fabric guiding device according to Claim 1.

13. Method for positioning a lower bridge and/or an upper bridge of a fabric guiding device of a weaving machine, wherein the fabric guiding device comprises first automatic clampers which are provided in order to release and secure the ends of the upper bridge and/or the lower bridge, in that, before positioning the lower bridge and/or the upper bridge, the clampers clamping the lower bridge and/or the upper bridge, respectively, are released and in that, when the desired position has been reached, the first clampers clamp the ends of the upper bridge and the lower bridge in order to hold these in the desired position.

14. Method according to claim 13 for positioning a lower bridge of a fabric guiding device of a weaving machine, having at least a lower bridge, wherein the fabric guiding device comprises first automatic clampers which are provided in order to clamp the ends of the lower bridge, and comprises second automatic clampers which are provided in order to secure the lower bridge between its two ends, wherein before the ends of the lower bridge are clamped with the first clampers: a. the first and second automatic clampers, which secure the lower bridge, are released, b. said lower bridge is moved until the desired position between the two ends is reached, c. after which the second automatic clampers secure the lower bridge between its two ends, d. after which the two ends of the lower bridge are then positioned further.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In order to further explain the properties of the present invention and to indicate additional advantages and particulars thereof, a more detailed description of a fabric guiding device according to the present invention now follows. It will be clear that nothing in the following description can be interpreted as a limitation of the scope of protection of the present invention defined in the claims.

(2) In this description, reference numerals are used to refer to the attached drawings, in which:

(3) FIG. 1 shows a perspective view of an embodiment of a fabric guiding device according to the invention with the lower bridge and the upper bridge in the coupled position;

(4) FIG. 2 shows a front view of the device illustrated in FIG. 1;

(5) FIG. 3 shows a rear view of the device illustrated in FIG. 1;

(6) FIG. 4 shows a detail view of the area B encircled in FIG. 2;

(7) FIG. 5 shows a detail view of the area C encircled in FIG. 3;

(8) FIG. 6 shows a detail view of the area A encircled in FIG. 1.

DETAILED DESCRIPTION

(9) An embodiment of the present invention is a fabric guiding device (1) for a face-to-face weaving machine, illustrated in FIGS. 1 to 3. This comprises a cutting knife (8) and an upper bridge (2) and a lower bridge (3) which are positionable with the aid of drive means (4a; 4b) at an adjustable distance from one another and from the cutting knife. The cutting knife is movable on a guide which is securely connected to the machine frame.

(10) The drive means (4a; 4b) comprise a first (4a) and second (4b) drive means. The drive can be realized manually (adjustable screw spindle), electrically (screw spindle+servomotor+gear unit) or hydraulically (hydraulic servo cylinders). In the illustrated device (1), the drive means (4a; 4b) are mechanically connected to the ends of the lower bridge (3). The system which guarantees the vertical movement of the lower bridge mainly comprises a mounted screw spindle and a servomotor with a gear unit. The upper bridge (2) does not have its own drive for its positioning. In order to move (position) the upper bridge (2), it can be mechanically connected to the lower bridge (3), in which case both move together. In order to realize the mechanical connection (coupling) between the lower bridge (3) and the upper bridge (2), the device (1) comprises coupling means (5) which are switchable between a first position in which the upper bridge (2) and the lower bridge (3) are coupled to one another, as a result of which the upper bridge (2) and the lower bridge (3) are positionable together with the aid of said drive means (4a; 4b), and a second position in which the upper bridge (2) and the lower bridge (3) are decoupled from one another so that only the lower bridge (3) is positionable with the aid of the drive means (4a; 4b).

(11) The mechanical connection between the lower bridge (3) and the upper bridge (2) can be engaged or disengaged at any position. The mechanical connection is achieved by an adjustable mechanical locking element or with the aid of a connection based on friction (clamping based on hydraulic machine clamps), optionally combined with said adjustable mechanical locking element. The mechanical locking element can be actuated electrically, hydraulically or pneumatically. For instance, it is possible to first bring the upper bridge (2) into position in order to then disengage the mechanical connection and subsequently to bring the lower bridge (3) into position. Once the set position has been reached, the lower bridge (3) and the upper bridge (2) are secured in this position. To this end, the device (1) is provided with first automatic clamping means (6).

(12) In order to limit bending of the lower bridge (3) under load (during weaving) and thus to achieve a good and constant product quality, the middle of the lower bridge (3) must be supported. To this end, the device (1) comprises second automatic clamping means (7) which are provided in order to secure the lower bridge (3) between its two ends when the desired position has been reached. The actuators which actuate the automatic clamping means may be of a pneumatic, hydraulic or electric type.

(13) This support provided by the second automatic clamping means (7) is passive. In the context of the invention, passive support is understood to mean that a certain middle position can be guaranteed, but that the support itself cannot change this position. The following text contains an explanation of this passive support.

(14) In order to keep the bending of the lower bridge (3) under control, the desired positions of the ends of the lower bridge (3) will also be used as the basis for a desired middle position. The desired middle position will always be in relation to the position of the ends of the lower bridge (3).

(15) The middle support is activated when the desired middle position has been reached. The desired middle position of the lower bridge is realized by moving the entire lower bridge upwards/downwards until the desired middle position has been reached. At that point, the middle support is activated and this middle position is thus secured.

(16) The system of passive support described above can be expanded, as explained below, to include an active component. Active is used to refer to the fact that the support can not only secure the middle position but that this system is also able to change this position itself independently of the ends of the lower bridge. This expansion does require an additional (third) drive means which is positioned in the vicinity of the middle and which is able to compensate for the bending of the lower bridge in a simple manner.

(17) When the desired position of the lower bridge (3) and/or the upper bridge (2) is reached, the position is secured by clamping both ends of the bridges against the supports via the first clamping means (6). This removes any degree of freedom. These supports are mounted against the chassis of the machine. The connection is based to a significant extent on friction. The clamping is effected by means of machine clamps which can be automatically engaged and disengaged. The machine clamps operate on the basis of hydraulic pressure or on the basis of a mechanical spring which can be hydraulically disengaged.

(18) The machine clamps move together with the bridges, which is possible owing to the fact that grooves are present in the supports and because the clamps can assume different positions on the bridges.

(19) The bridges are clamped during the operation of the machine; the clamps are only released in order to carry out positioning.

(20) The load on the system for positioning can be reduced by reducing the tension on the yarns during the positioning of the upper bridge and/or the lower bridge and/or by adjusting the angle of the yarn with the horizontal plane. Prior to the positioning, the machine control unit will lower the yarn tension on the lower bridge and the upper bridge and/or adjust the position of the weaving frames. After the positioning, these changes will be reversed.

(21) The fabric guiding device (1) according to the present invention can also be provided with position sensors (9) arranged at both ends of the device, either to measure the distance of both the upper bridge (2) and the lower bridge (3) from the cutting knife (8) or to measure the mutual distance between the upper bridge (2) and the lower bridge (3), or both. These measurement signals recorded by the position sensors (9) can be displayed within the visual field of the user (operator). During the adjustment of the bridges, he can simply read off what the new jaw height is (in the case of measurement of the distance between the upper bridge (2) and the lower bridge (3)) or what the new distance is between the upper bridge (2) and the cutting knife (8) and/or between the lower bridge (3) and the cutting knife (8) (in a good setting, both of these distances should be substantially identical). In this way, the user immediately sees the effect of his adjustment and can terminate it once he has reached the desired jaw height and thus the desired pile height resulting therefrom. The position sensors used are, for example, contactless sensors such as those based on laser beams, for example.

(22) A processor unit can also be used in order to move the upper bridge (2) and/or the lower bridge (3) over a specified distance via the drive means in combination with the signals from the position sensors. In this case, the first (4a) and the second (4b) drive means are preferably actuated synchronously.

(23) Furthermore, the fabric guiding device (1) can also be provided with one or more position sensors in the middle of the lower bridge. With the display of the measurement signals from this (these) position sensor(s) in combination with the desired middle position of the lower bridge, the user can minimize the bending of the lower bridge during the positioning of the lower bridge. If there are no position sensors in the middle of the lower bridge, the user can provide the processor unit with a (manual) measurement value for the bending of the lower bridge, so that it is still possible to take into account the bending during the movement of the lower bridge and thus minimize the bending to the greatest possible extent.