EP0290788B1 - Device for the selective movement of the feed-fingers in looms - Google Patents

Description

The invention relates to a device on weaving machines for selectively moving swiveling master fingers between a rest position and an operating position with a shaft running synchronously with the weaving machine, which is provided with a control cam, the movement of which can be transmitted to a master finger with transmission means that select one Master fingers control electromagnets included.

In a known type (EP-B1-9840) a two-armed lever is provided, which is held with its center on the control disk of the shaft. One of the ends of this lever is connected to a master finger via a transmission linkage. The transmission linkage contains a spring mechanism that holds the original finger and thus also the articulation point on the two-armed lever in the rest position. The other end of the double arm lever, which is held in contact with the control cam with a relatively soft spring, is opposite a magnetic lock which is adjustable between a rest position and a locking position by a control magnet. If the control magnet is excited, the otherwise freely movable end of the double-armed lever is held so that the other end of the lever is then moved with the transmission mechanism leading to the original finger, ie the original movement of the original finger is carried out.

In order to increase the possible speeds and not to be dependent on the switching speeds of the electromagnets, it is also known (US-A-45 37 228) to provide a locking lever for the double-armed lever, which is separated from a rest position and a locking position by a second cam is pivotable. In this type of construction, electromagnets are also provided, which, however, only have the effect that, when they are actuated, the locking lever moved by the second control cam is held in the locking position.

In a further known device (EP-B1-131 481) a tilting device is assigned to each template finger, which is connected to the template finger and which is brought into the operating position or rest position by the transmission means in the form of a positive drive. The transmission means contain a rod running against the tilting device, the feed direction of which can be controlled by means of an electromagnet.

The invention is based on the object of designing a device of the type mentioned at the outset in such a way that, even at very high working speeds, it allows the individual template fingers to be brought forward and moved back exactly in time.

This object is achieved in that each master finger is assigned a snap drive which snaps it after a dead center into the rest position or operating position, and that each master finger can be coupled to the transmission means in the rest position or in the operating position by means of the electromagnets and from these from the respective position can be taken beyond the dead center of the snap drive.

The device designed according to the invention enables high working speeds that do not depend on the switching and response times the electromagnet is affected. Even with very fast movements, there are still relatively large periods of time available for retracting and extending the magnet armature of the electromagnet.

In an expedient embodiment of the invention, it is provided that the snap drive of each template finger contains a disk which is fixedly connected to the template finger and is mounted on an axis of rotation, which disk can be rotated back and forth between two stops and to which a spring element held at a fixed stop is articulated in such a way that that the articulation point of the spring element on the disc in the rest position and in the operating position is on opposite sides of the connecting line between the fixed stop of the spring element and the axis of rotation of the disc. This creates a simple yet effective snap mechanism that also allows very high working speeds.

In a further embodiment of the invention it is provided that the electromagnets are arranged within the transmission means in such a way that a positive connection can be established between two successive transmission means. This positive connection in both directions delays or the like due to elastic deformations. avoided.

In an advantageous embodiment of the invention it is provided that the electromagnets are arranged on swivel levers which can also be pivoted in the circumferential direction of the disk which can be pivoted with the associated reference finger, the magnet armatures of the electromagnets being assigned recesses in the disk into which the magnet armature can be latched.

In a further embodiment of the invention it is provided that the operating position and the rest position of the original fingers is so limited by the stops that in both positions there is play in the circumferential direction between the magnet armatures of the electromagnet which can be activated in each case and the cutouts. This ensures that the magnet armatures of the electromagnets snap into the corresponding recesses of the disk practically without force, so that the engagement and disengagement is not delayed by frictional forces.

Further features and advantages of the invention result from the following description of the embodiment shown in the drawing and the subclaims.

The drawing shows a schematic side view of a device according to the invention for moving template fingers of a weaving machine between an operating position and a rest position.

The device shown is used to alternately bring weft threads to weaving machines. It contains several template fingers (23), only one of which is shown. The original fingers (23) can be pivoted about a stationary axis (11), i.e. in the view shown, the template fingers (23) lie one behind the other in the plane of the drawing.

The drive of the master fingers (23) is derived from a shaft (21) which is driven at a constant speed and which runs synchronously with the weaving machine, and e.g. has the speed of technical education resources. For example, the rotation of the shaft (21) can be derived directly from the main shaft, from which the movement of the means for shedding is also derived.

The shaft (21) is provided with a control cam (2) against which a rocker (1) is pressed. The rocker (1) can be pivoted about an axis (22) which is stationary with respect to the shaft (21) and is pressed onto the control cam (2) by means of a compression spring (24). The control cam (2) has two concentric, partially cylindrical ones Sections (17, 18) which lie in a different radius to the shaft (21). Transitional sections (30, 31) are provided between the sections (17, 18).

Two transmission rods (3, 4) are articulated to the rocker (1) in a joint (25), which diverge approximately in a V-shape. At the two ends of the transmission rods (3, 4) pivot joints (5, 6) are connected via joints (26, 27), which can be pivoted about the axis of rotation (11) of the guide fingers (23). The pivot levers (5, 6) converge again in a V-shape, so that the transmission rods (3, 4) and the pivot levers (5, 6) form a quadrilateral, the axis of rotation (11) and the joint (25), which Transmission rods (3, 4) connects to the rocker (1), are arranged in diagonally opposite corner points.

The swivel levers (5, 6) are each provided with an electromagnet (8, 9), which in turn each have a magnet armature that can be extended, for example, radially to the axis of rotation (11). The template fingers (23) are each rotatably connected to a disc (7) which is mounted on the axis of rotation (11). The disc (7) is provided with a shoulder (29) which projects between two fixed stops (12, 13) which thus determine the operating position and the rest position of the original fingers (23).

The disc (7) is provided with radial cutouts (19, 20) which are assigned to the magnet armatures of the electromagnets (8, 9).

A snap drive (10) acts on the disks (7), which is designed such that the disks (7) and thus the platen fingers (23) are each held in the rest position or operating position by the force of a spring element (14). in which their approach (29) abuts one of the stops (12, 13). When moving from the rest position to the operating position or vice versa, the snap drive (10) passes through a dead center position, after which it then snaps the disk (7) and thus also the associated template finger in the respective other direction. The snap drive (10) consists of a telescopic spring element (14) which is arranged between a fixed stop (16) and a pivot point (15) on the disc (7) under prestress. The arrangement of the stopping point (16) and the articulation point (15) is such that the articulation point (15) in the operating position and in the rest position of the template fingers (23) on the other side of the connecting line between the axis of rotation (11) and the Breakpoint (16) is.

Each template finger (23) is firmly provided with a disc (7). Each disc (7) is assigned two electromagnets (8, 9). In a practical embodiment, at the end of an axis of rotation (11), i.e. at the end of a row of template fingers, each pivot lever (5, 6) are arranged, which are connected to one another by transverse guides, on which the electromagnets (8, 9) are then arranged, which are assigned to the individual template fingers (23).

As already mentioned, the shaft (21) rotates constantly with the control cam (2). The selection of the template finger (23), which is to be brought into the operating position or into the rest position, takes place via a program control by means of which the electromagnets (8, 9) of the individual template fingers (23) are controlled. In the position shown, the platen finger (23) is in its operating position, for example. To move it back to the dotted rest position, the disc (7) must be turned counterclockwise. This twisting is controlled by the electromagnet (8), the armature of which lies opposite the recess (19) of the disc (7) in this position. The actuation of the electromagnet (8) expediently takes place as long as the rocker (1) is still in the area of the cam section (17), so that a relatively long period of time is available for extending the magnet armature of the electromagnet (8). Then when the cam section (30) runs against the rocker (1), it will pivoted, this pivoting movement being transmitted via the transmission rods (3, 4) to the pivoting lever (5,6). The electromagnet (8) coupled with the disk (7) takes the disk (7) with it and pivots it counterclockwise. The recess (19) is kept so wide in the circumferential direction that the magnet armature of the electromagnet (8) can move into the recess (19) without contact. When pivoting the swivel lever (5) with the electromagnet (8), its magnet armature rests against a side wall of the recess (19) and takes the disk (7) with it. As soon as the snap drive (10) has passed its dead center, it snaps, whereby the disc (7) is moved counterclockwise. In the end position of the disc (7), the shoulder (29) lies against the stop (13). This end position is reached when the rocker (1) runs against the cam section (18) with the larger radius. The recess (19) is kept so wide that even in this position it is free of the magnet armature of the electromagnet (8) so that it can be withdrawn without overcoming frictional forces. The entire time over which the rocker (1) is in contact with the cam section (18) is available for this. If the magnet armature of the electromagnet (8) is retracted and is kept retracted while the rocker arm (1) lies against the cam section (18), the disk (7) and thus the platen finger (23) remain in the rest position shown in broken lines.

There are two different options for advancing the master finger (23), ie advancing the master finger (23) is possible in two different positions of the cam disc (2). As soon as the cam disc (2) starts again with the cam section (18) on the rocker (1), the electromagnet (8) can be excited again so that its magnet armature engages again in the recess (19). The disc (7) is then moved back clockwise again, resulting in the reverse sequence of movements, so that the snap drive (10) after the dead center has passed the further transport Disc (7) takes over until its shoulder (29) runs up to the stop (12). In the rest position of the platen finger (23) shown in dashed lines, the cutout (20) also lies opposite the magnet armature of the electromagnet (9) when the rocker (1) lies against the cam section (17). During this time, the electromagnet (9) can thus be excited so that its magnet armature engages in the recess (20) and the movement given when it starts up against the cam section (30) of the rocker is transmitted back to the disk (7) in the clockwise direction becomes.

Furthermore, it is possible to leave the magnet armature of the electromagnet (8) or of the electromagnet (9) in the extended position, i.e. in engagement with the recess (19) or the recess (20) so that the coupling between the rocker (1) and the disc (7) is maintained during the complete rotation of the shaft (21). This then means that the original finger (23) is advanced and withdrawn when the shaft (21) rotates.

Claims (8)

1. Device at a loom for selectively moving swinging feed-fingers (23) between a rest position (at 13) and an operative position (at 12) by means of a shaft revolving in synchronism with the loom which shaft is provided with a control cam (2) whose movements can be transmitted to one of the feed-fingers by means of transmission means (1, 3, 4, 5, 6, 7), the latter comprising electromagnets (8, 9) controlling the selection of the respective feed-finger, characterized in that each feed-finger (23) has assigned to it a snap-in actuator (10) for snapping the feed-finger into the rest position or into the operative position, respectively, after a dead center has been passed, and wherein each feed-finger (23) can be coupled with the transmission means (1, 3, 4, 5, 6, 7), by at least one electromagnet (8, 9), in the rest position (at 13) or in the operative position (at 12), and can be entrained by them from the respective position and beyond the dead center of the snap-in actuator (10).
2. Device according to claim 1, characterized in that the snap-in actuator (10) of each feed-finger (23) comprises a disk (7) which is fixed to the feed-finger (23) and seated on an axis of rotation (11) for rotating to and fro between two stops (12, 13), with a spring element (14) fixed at a stationary mounting point (16) being articulated on the disk (7) in such a way that the articulation (15) of the spring element (14) on the disk (7) comes to lie on different sides of the interconnecting line between the stationary mounting point (16) of the spring element (14) and the axis of rotation (11) of the disk (7) in the rest position and in the operative position, respectively.
3. Device according to claim 1 or 2, characterized in that the electromagnets (8, 9) are arranged in the transmission means (1, 3, 4, 5, 6, 7) in such a way that a form-locking connection can be established by them between two successive transmission means (5, 7; 6, 7).
4. Device according to any of claims 1 to 3, characterized in that the control cam (2) comprises two partially cylindrical, concentric cam sections (17, 18).
5. Device according to any of claims 1 to 4, characterized in that the electromagnets (8, 9) are arranged on rocking levers (5, 6) which are arranged to likewise swing in the circumferential direction of the disk swinging together with the associated feed-finger (23), the armature of the electromagnets (8, 9) having assigned to them recesses (19, 20) in the disk (7) for snapping engagement by the armatures.
6. Device according to claim 5, characterized in that the operative position and the rest position of the feed-fingers (23) are defined by stops (12, 13) in such a way that a circumferential play remains in both positions between the armatures of the respective electromagnets (8, 9) that can be activated, and the recesses (19, 20).
7. Device according to any of claims 1 to 6, characterized in that a rocker (1) adapted for rocking about an axis (22) extending in parallel to the shaft (21) is urged against the control cam (2), the rocker (1) being followed by transmission rods (3, 4), on which rocking levers (5, 6) are articulated, which latter are adapted to rock about the axis of rotation of the disks (7) and which carry the electromagnets (8, 9) with the armatures than can be brought into snapping engagement with the recesses (19, 20) of the disks (7).
8. Device according to claim 7, characterized in that the transmission rods (3, 4) and the rocking levers (5, 6) - viewed in the direction of rotation of the disk (7) and of the shaft (2) - form a rectangle whose diagonally opposite corner points are formed by the point of articulation (25) of the transmission rods (3, 4) on the rocker (1) and the axis of rotation (11) of the disk 7.

Images