EP2571638A1

EP2571638A1 - Holder device for securing a wire blank

Info

Publication number: EP2571638A1
Application number: EP11719284A
Authority: EP
Inventors: Bengt Forsberg
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-17
Filing date: 2011-05-16
Publication date: 2013-03-27
Also published as: CN102917814B; JP2013527035A; SE1050480A1; CN102917814A; SE534834C2; JP5746327B2; WO2011144562A1

Abstract

The invention relates to a holder device (1) for securing a wire blank (2) in a working position in a bending machine, wherein the holder device comprises a base part (5) having a seat (7) which has a part-circular recess (8) for the wire (2), against which the wire is held during the bending, a holder part (6) which has a part-circular recess (9) and which is arranged to be switched between a securement position for securement of the wire and at least one release position in which the wire can be moved relative to the seat, and a drive mechanism (11) which is driven by a drive motor in order to produce the switching movement in which the holder part is arranged on the front, outer end of a drive arm (10) forming part of the drive mechanism, in which the drive arm is suspended from the drive mechanism at its inner end, and in which the holder part is supported by a slide face (20) which is fixed in the base part and which interacts with a movable slide face on the holder part. The advantage of the invention is that a strong securement of a wire in a bending machine is enabled, which at the same time allows a rapid release of the wire such that a fast and reliable bending process is obtained.

Description

HOLDER DEVICE FOR SECURING A WIRE BLANK

TECHNICAL FIELD The present invention relates to a holder device intended to secure a wire blank or the like in a wire bending unit.

BACKGROUND ART Within the manufacturing industry, wire is often bent into construction components or finished products. The wire should here be secured as close to the bending point as possible. Hitherto known holders do not however meet exacting requirements for rapid switching between a release position and a securement position, and for stable securement with large securing force in all directions. Corresponding requirements can also be placed on holders intended to secure wire blanks and other elongate objects in contexts other than bending.

DISCLOSURE OF INVENTION

The object of the present invention is to provide a rapidly switchable holder device which lends stability in all directions.

The above objects are achieved by means of the invention, whose characteristics emerge from the following Patent Claim 1.

BRIEF DESCRIPTION OF DRAWINGS The invention will be described below on the basis of an example with reference to the appended drawings, in which:

Fig. 1 is a perspective view of a holder device according to the invention,

Fig. 2 is a side view of a holder device according to the invention in a fully releasing position,

Fig. 3 is a partly broken side view of the holder device in a securement position,

Fig. 4 shows schematically a bending machine provided with the holder device according to the invention. MODE(S) FOR CARRYING OUT THE INVENTION

The holder device 1 shown in Figs. 1, 2 and 3 is intended to secure an object 2, such as a wire or a wire blank, in a bending machine during the actual bending process. The holder device 1 is in the bending machine mounted on a laterally movable slide, which makes the holder device able to be moved in a lateral direction to the various bending positions on the wire. The wire is secured by a centrally placed centre holder, which can also rotate the wire about its longitudinal axis if required. The longitudinal direction of the wire is oriented in the x-direction, in which the centre axis 3 of the wire also runs. In the shown illustrative embodiment, the holder device 1 is mounted together with a bending tool, which also comprises a bending die and a bending counter-die, so that a bending unit is formed. In the shown example, the bending die comprises no bending elements for bending the wire. Once the bending process is complete, the holder device can rapidly release the wire so that the bending unit can move sideways into the next bending position. The holder device 1 comprises a base part 5, which is fixedly mounted on the frame 4 of the holder device, and a holder part 6, which is movable between a securement position, in which the wire 2 is secured, and a plurality of release positions, in which the wire in a freed position is released yet held in place and in which the wire, in another freed position, can be introduced into and removed from the holder device. The holder part 6 is constituted by a front part of a drive arm 10. The holder part 6 interacts with a seat 7 fixedly mounted on the base part 5, which seat has a forward-directed part-circular recess 8, which is intended as a support surface for the wire 2. The front part of the holder part is configured with a hook-shaped projection, so that a semi-circular recess 9, facing the seat 7, is formed. The holder part 6 is intended to execute a main movement in the direction of the seat 7, i.e. in the y-direction, in order to gain the securement position. With a movement in the opposite direction away from the seat 7, the holder part gains the release position. During this movement, the holder part will also execute a slight movement in the z-direction, so that the front, bottom edge 24 of the holder part ends up vertically above the wire when the holder part is in an outer release position. In the securement position, the recess 8 of the seat and the recess 9 of the holder part are positioned in the same plane. The recess 9 of the holder part is broadly semi-circular, with a radius somewhat larger than the wire material, and the recess 8 of the seat constitutes a lesser part of a semi- circle, also with a radius somewhat larger than the wire material. This means that the wire will be clamped between the surfaces of the recesses when the holder part is in the securement position. The movement of the holder part is produced by a substantially to-and-fro motion of the drive arm 10, i.e. along the y-axis. This movement is obtained by a drive mechanism 11, consisting of a drive motor 12. In this example, the drive motor is of the rotary type, for example an electric motor, a pneumatic motor or a hydraulic motor having a toothed gearing 13 and an eccentric mechanism in the form of an eccentrically fitted drive pin 14 on a wheel 15.

The drive arm 10 is contrived to transmit large forces, yet with a certain flexibility to compensate for tolerances and, as can best be seen from Fig. 1, is powerfully constructed in, for example, solid square steel of a somewhat resilient material type, such as spring steel. The drive arm is configured with a substantially straight horizontal portion 16, which is arranged substantially in the y-direction, an arc- shaped portion 17, and a shorter vertical portion 18, which is arranged in the z-direction. The drive shaft is terminated in a hub portion 19, which has a central hole forming the bearing point for the drive pin 14. The rotary movement of the drive motor will hereby be translated into a substantially to-and-fro motion of the drive arm 10, wherein the holder part and its recess 9 move between the securement position and the release positions for the wire 2. Depending on the rotation of the wheel 15, and hence upon the movement of the drive arm, the holder part and its recess 9 can adopt four specific positions, firstly a securement position, secondly an inner release position, in which the wire can be rotated and displaced relative to the holder part, yet still held in place, thirdly an outer release position, in which the wire can be introduced into and removed from the holder device in a direction transverse to the longitudinal direction of the wire, and fourthly an outer end position, in which the drive arm 10 can easily be exchanged for a drive arm having a holder part which has a recess 9 adapted for another wire dimension. It is also possible to fasten the holder part to the drive arm with a fastening element such that only the holder part needs to be changed when the wire dimension is changed.

The drive arm 10 is thus suspended at its rear or inner end from the drive pin 14 and supported at its front or outer end, i.e. at the holder part, by at least one upwardly directed fixed slide face 20 of the base part 5, the holder part having a movable slide face 21 directed downwards, towards the fixed bearing surface. The slide face 21 is configured to give the recess 9 of the holder part its very short switching movement between the securement position and the inner release position, in which the switching movement is respectively directed substantially outwards and inwards, i.e. in the y-direction. The movement into the outer release position also involves a lifting movement of the holder part in the z-direction, so that the recess 8 of the seat 7 becomes freely accessible directly from the front to facilitate introduction of a new wire and removal of a ready-bent wire. This is achieved by configuring the holder part with an angled portion 22, which interacts with a corresponding fixed surface 23 on the base part or against at least one edge on the fixed slide face 20. In order to be able to introduce and remove a wire directly from the front, the bottom edge 24 of the holder part should in the front release position be raised to a level which lies above the top edge of the recess 8 on the seat 7. Advantageously, the vertical distance between the bottom edge 24 of the holder part and the top edge of the recess 8 is in the order of magnitude of one wire diameter, as is illustrated in Fig. 1. In this way, a wire can be reliably fed into or withdrawn from the bending holder, even if it is somewhat bowed, which is often the case when long wires are to be bent.

To enable the drive arm 10 to absorb large forces in the longitudinal direction of the wire, i.e. in the x-direction, the drive arm is advantageously supported in the lateral direction by mutually opposing support surfaces on the bending holder, which in the securement position can absorb the tensile forces acting on the wire, and thus acting in the lateral direction on the drive arm 10, in connection with, for example, a bending moment. According to one advantageous embodiment, the frame has a lateral guide for the drive arm 10 in the form of a side wall 26, which interacts with a support lug 27 on the holder part 6. The support lug and the side wall are advantageously configured such that the opposite- situated support surfaces are active, i.e. interact in at least the securement position, but also in the two release positions. Advantageously, however, they do not interact in the outermost position, i.e. in the end position, but rather in the end position they are mutually displaced such that they are set free from one another. This enables the drive arm to be removed with a sideways movement. The drive arm can hence easily be exchanged for another drive arm, usually when the holder part, and thus the drive arm, is to be adapted to another wire dimension. If the holder part is detachably fastened to the drive arm, the support surfaces can also interact in the end position. The mechanism is here configured such that the drive arm is allowed to be pulled off from the pin when the holder part is in the end position, but not in any of the operating positions. In other positions, the arm is barred from possible removal by either the support surfaces and/or another blocking part. A simple removal and mounting of the drive arm is an important characteristic, since the bending holder must be adapted for different wire dimensions. Fig. 3 shows the holder part, with the recess 8, in its outer, raised release position with dashed lines. The holder part in the securement position, in which the wire is clamped with great force between the surface on the recess 8 of the holder part and the surface on the recess 9 of the seat, is shown with unbroken lines.

Switching from the release position to the securement position is realized by the drive motor 12 rotating the rotary mechanism in Fig. 2 anti-clockwise, which means that the drive arm 10 is pulled rearwards until the securement position is adopted. The configuration of the drive arm 10 as a crank lever having an arc- shaped portion, and the construction of the arm in a high- strength material with a high degree of rigidity, yet still with a certain elasticity, i.e. resilience, ensures that the wire is reliably secured without harming of the wire or generation of unnecessary stresses in the mechanism, since the drive arm has a certain elasticity, above all in the arc- shaped portion 17, but also in the straight portions 16 and 18. This means that a certain pretension can be applied by the holder part to the wire 2 in the seat 7. By adjusting the angle of the drive pin 14 in the securement position, it is possible to obtain a high gear ratio of the power transmission from the drive motor in the securement position.

The inner release position differs insignificantly from the securement position. The distance between the positions in the y-direction is advantageously less than one wire diameter, so that the securement force on the wire ceases and the wire is free to be rotated about its longitudinal axis or displaced in its longitudinal direction. At the same time, the wire is held in place in the lateral direction, i.e. in the y-direction and z-direction, during the rotation and the displacement.

Fig. 4 shows a work bench 28 or equivalent in a bending machine for bending an object 2 such as a wire or wire blank by means of bending tools. The shown bending machine comprises two holder devices 1, two bending tools 29 and a centrally, fixedly placed centre holder 30. Like bending tools are known to the person skilled in the art and are not described in further detail. In the shown example, the bending tools are integrated with the holder devices to form a bending unit, the above-described holder device 1 according to the invention forming part of the machine and serving as a holder for the wire 2 during its bending. The centre holder 30 is intended both to secure the wire when the bending units move sideways in the bending machine, when the holder devices are in the inner release position, and also to rotate the wire about its longitudinal axis. The bending units are movably mounted on a slide or the like and can be moved in the longitudinal direction of the wire into chosen positions along the wire in which bending shall take place in a relative direction that is chosen by the rotational position for the wire chosen by the centre holder for each bending. The holder device 1 has an operationally reliable and simple construction, which can be realized at low cost. Furthermore, it is easily accessible when the holder device is to be adapted for different wire blanks and in the event of possible maintenance and adjustment. The fact that bending can be carried out in the vicinity of the holder device lends stability to the work operation. The operating problems which often occur with known devices due to lack of space are wholly eliminated if the device 1 according to the invention is used.

Without breaching the scope of the inventive concept, modifications of the device according to the invention will probably be possible. The device is thus not limited to that which has been shown and described in connection with the illustrative embodiment, but solely by the following patent claims. For example, the drive arm can be configured with a circular cross section in which the holder part is configured for lifting action in the outer release position and with lateral support. The drive motor can also be a linear motor, for example a hydraulic motor acting on the drive arm, which can be straight, appropriate flexibility being attainable through the choice of suitable characteristics for the drive motor.

Claims

1. Holder device (1) for securing an elongate object (2), such as a wire blank, in a working position in a working machine for machining or treatment of the object in one or more work operations, wherein the holder device (1) comprises a base part (5) comprising a seat (7) having a part-circular recess (8) for the object (2), against which the object is held during the work operations, a holder part (6) having a part-circular recess (9), in which the holder part (6) is arranged to be switched between a securement position for securement of the object (2) and at least one release position in which the object (2) can be moved relative to the seat (7), and a drive mechanism (11) for producing the switching movement driven by a drive motor (12), characterized in that the holder part (6) is contrived to move towards and away from the seat with the switching movement, in that the holder part (6) is arranged on the front, outer end of a drive arm (10) forming part of the drive mechanism, in that the drive arm (10) is suspended from the drive mechanism at its inner end, and in that the holder part (6) is supported by a slide face (20) which is fixed in the base part (5) and which interacts with a movable slide face (21) on the holder part (6).

2. Holder device according to Patent Claim 1, characterized in that the drive motor (12) and the drive mechanism (11) are contrived to switch the holder part between two different release positions, in which an inner release position enables a lateral movement and a rotation of the wire in the seat (7), and in which an outer release position enables a movement of the object (2) to and from the seat (7).

3. Holder device according to Patent Claim 1, characterized in that the drive arm (10) has a horizontally lying portion (16), at whose front end the holder part (6) is arranged, and a vertically standing portion (18), which is coupled to an eccentric mechanism forming part of the drive mechanism, which portions are linked by an arc-shaped portion (17), in which the arc- shaped portion is contrived to create a rigid, yet, when the drive arm (10) is subjected to tensile load in the securement position, somewhat resilient transition between the drive device (12) and the holder part (6).

4. Holder device according to Patent Claim 3, characterized in that the base part (5) and the drive arm (10) have mutually interacting portions having mutually opposite side faces (26, 27), which are directed and placed such that in the securement position they can absorb the tensile forces acting laterally on the holder part (6).

5. Holder device according to Patent Claim 4, characterized in that the drive arm (10) is switchable into an outer end position, in which the opposite side faces are mutually displaced such that they do not interact, but allow removal of the drive arm in the lateral direction in order, for example, to change to another drive arm.