EP2490840B1

EP2490840B1 - Holding device for holding an object such as a wire blank

Info

Publication number: EP2490840B1
Application number: EP10805485.9A
Authority: EP
Inventors: Bengt Forsberg
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-10-20
Filing date: 2010-10-18
Publication date: 2013-08-07
Anticipated expiration: 2030-10-18
Also published as: SE0950774A1; WO2011048501A2; EP2490840A2; PL2490840T3; WO2011048501A3; CN102712029B; SE534218C2; JP2013508164A; CN102712029A; JP5624151B2

Description

TECHNICAL FIELD

The present invention relates to a device for holding an object, preferably an elongate object 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 and, where appropriate, for also rotating the object during the said work operations, according to the preamble to the following Patent Claim 1. Within manufacturing industry, wire often gets to be bent into construction components or finished products. At present, such manufacture takes place in automatic bending machines, which are supplied with wire or wire blanks. However, known bending machines have holder devices with certain limitations, which means that the configurations of the products are limited.

BACKGROUND ART

In a known type of holder devices for use with bending tools, for example US 4,662,204 , the wire is held in a fixed position while the wire is bent. Such a tool has a certain width and a use of the tool means that bending of the wire cannot be carried out along a certain length of the wire, i.e. the length which is occupied by the holder device and further length of the wire closest to the bending tool.

DISCLOSURE OF INVENTION

One object of the present invention is to enable a bending of a wire along further length of the wire, i.e. that length of the wire which is occupied by the tool for securing the wire during the work or bending operation.
Another object of the invention is that bending of a wire or a wire blank shall be able to be carried out in three dimensions with a device according to the invention.
According to the invention, the said objects can be met by a holder device for securing the wire during the bending operation. The wire or the wire blank is here held during the bending operation by a holder device which is separate from the bending tool itself, whereby that part of the device which occupies the length of the wire for securement of the wire can be configured with shorter length, i.e. that part of the tool which holds the wire is of smaller dimension. Furthermore, the journaling bearing of the device can be arranged at a distance from the working region and thus does not encroach upon the limited space which is present adjacent to the region in which bending might wish to be carried out. The device, which is relatively simple in its design and substantially mechanically constructed, is reliable in its use and can be produced at relatively low cost.
The device is characterized according to that which is stated in the characterizing part of Patent Claim 1. The holder device is rotatable about a centre of rotation which corresponds or substantially corresponds with the longitudinal axis for the object which is to be machined or treated, i.e. in the principal extent of the object in the seat in the holder. Furthermore, the holder is mounted in bearing points situated at a distance from its centre of rotation.
According to one embodiment of the device according to the invention, a control unit and/or a drive unit is/are arranged at a still greater distance from the said centre of rotation than the bearing points for the holder.

BRIEF DESCRIPTION OF DRAWINGS

In the following description, further characteristics and advantages of the device according to the invention will emerge from illustrative embodiments, wherein simultaneous reference will be made to appended, schematic drawings, in which:

Fig. 1 shows from one side an embodiment of a holder device according to the invention securing a wire or a wire blank,
Fig. 2 is a perspective view of a part of the holder device,
Fig. 3 is a section along the line A-A in Fig. 1,
Fig. 4 is a section along the line B-B in Fig. 1,
Fig. 5 is a section along the line C-C,
Fig. 6 is a front view of the holder device,
Fig. 7 shows schematically a bending machine provided with the holder device according to the invention,
Fig. 8 shows from one side a part of a wire which is bent while secured by means of the holder device according to the invention, and
Fig. 9 shows from the same side a part of a corresponding wire, but which is bent while secured with a known securing method.

MODE(S) FOR CARRYING OUT THE INVENTION

Figs. 1 and 2 show an embodiment of a holder device 1 according to the invention, arranged with a suspension device 2 for suspending the holder device 1 from a working or bending machine for machining or treatment of an object 3 in one or more work operations.
The holder device 1 comprises a holder part 4 and a locking device 5 for securement by clamping, i.e. pinching of the object 3, which preferably is in the form of an elongate object such as a wire or a wire blank.
The holder part 4 has a seat 7 for the object 3, for example in the form of one or more surfaces in one or more portions which extend towards the seat 7 and guide the object supplied to the working machine in towards the seat such that the object acquires its intended position in the holder device 1.
According to the shown illustrative embodiment in Figs. 1 and 2, the locking device 5 comprises a locking member 9 having a locking lug 10 or equivalent and a drive member 11 in the form of a piston cylinder. In the example, the locking member 9 is fixed in the moving part 14 of the drive member 11, which moving part is the piston rod part of the piston cylinder. The cylinder part 15 is pivotably suspended from the holder device 1, which will be described in greater detail below.
In the open position, the seat 7 is arranged such that it is accessible for the supply of the object 3 to the seat 7. In a closed position 17, the locking member 9 is arranged to lock or hold the object 3 fixedly in the seat 7 through the application by the piston cylinder of a pressure force for tilting the locking member down against the seat, with the object situated therebetween for clamping thereof as in a nip, in a working position for at least one work operation. The object 3 cannot be displaced or rotated in the seat 7. Should the object 3 be rotated about its axis for a work operation in order to achieve, for example, another extent, bending in another direction, or bending in a further dimension of the object 3, the device 1 is arranged in such a way that the holder part 4 and the locking member 8 in the closed position, i.e. whilst supporting the object 3, can be rotated about a centre of rotation 34, as will be described in greater detail below.
The locking lug 10 of the locking member 9 can be provided with one or more oblique or angled edges or surfaces in order to ensure that an object 3 supplied to the seat 7 or the switching element 4 is guided or adopts the intended position in the seat 7, and that objects with varying dimensions can be secured by the locking member 9 in a locked position in the seat 7.
The centre of rotation for the holder part 4 and the locking member 9 coincides or substantially coincides with the longitudinal axis for the object 3 in its adopted position in the seat 7, or with the space for the object 3 in the seat 7.
The holder part 4 is mounted in bearings arranged at a distance from the centre of rotation, i.e. the seat 7, or at such a distance that the bearings do not encroach upon the limited space which is present adjacent to the area of engagement with the object 3 in order to secure it in the working machine. The holder part 4 is thus rotatably suspended from the suspension device 2 by means of upper and lower force and motion transmitting bearing arms 17, 18, in the example two in number, having a front end 19, 20 articulately connected to the holder part 4 at front, upper and lower pivot points 21, 22. The bearing arms 17, 18 are supported by the suspension device 2 via a transverse arm 23 and an upper and lower intermediate pivot point 24, 25, as well as a central intermediate pivot point 26. The bearing arms 17, 18 extend also rearwards from the transverse arm and, via rear, upper and lower pivot points 27, 28, are linked by a rear, force-transmitting transverse arm 29 to a central centre of rotation 30 at which the transverse arm 29 is arranged to be rotated by means of a rotatable drive shaft from a drive device 31, for example an electric motor, which is indicated schematically.
The bearing arms 17, 18 hereby form, together with the transverse arms 23, 29 and the holder part 4, a force and motion-transmitting parallel mechanism for translating a rotary motion from the drive shaft 30 of the drive device 31 into a rotary motion of the holder part 4 and its seat 7, and hence a rotary motion of a secured object 3, for example a wire. The rotary motion of the holder part 4 results from the fact that the bearing arms 17, 18 are articulately fixed in the holder part 4 at a distance from the centre of rotation, so that forces upon the bearing arms, in this case a pressure force on one and a tensile force on the other bearing arm, create a torque in the holder part for rotation thereof about its centre of rotation. In principle, a rotary motor can be replaced with a linear motor, such as a hydraulic or pneumatic piston cylinder, which acts on one bearing arm 17, 18 in its longitudinal direction.
In order to achieve high stability of the holder part 4, not least against tensile forces on the object 3 in its longitudinal direction, a support mechanism 32 having a fixed support portion, in the example in the form of a fixed support arm 33, which is supported by the suspension device 2 and extends forwards towards a support portion forming part of the support mechanism and movable with the holder part 4, is provided. This is formed by the rear side of the holder part 4 on a level with the seat 7, i.e. the centre of rotation of the holder part, which thus coincides with the longitudinal axis 34 of the object 3, i.e. in the example that of the wire. At the front end 35 of the support arm 33 are arranged fixed support surfaces 36-40, which are configured to interact with corresponding movable support surfaces 41-45 on the body 6 of the holder part 4, see Figs. 2 and 3.
The fixed support surfaces comprise at least one, in the example two or three concave circular-arc-shaped, more precisely cylinder-sector- shaped support surfaces 36, 37, 38 with the seat 7, i.e. the centre of rotation 34, as the centre of curvature, and a flat or, as in the example, two flat circular-sector-shaped, mutually facing support surfaces 39, 40. In principle, the concavely curved surfaces could be flat, though there is then no surface contact with the interacting movable surfaces.
The movable support surfaces 41-45 are constituted, as can best be seen from Fig. 2, by at least one, in the example two or three convexly curved, circular-arc-shaped or cylinder-sector-shaped support surfaces, which interact with the fixed, concavely curved support surfaces 36, 37, 38 and shall thus have a radius of curvature which is approximately as large as the corresponding fixed support surfaces or smaller than these. In addition, there are one or two movable support surfaces 44, 45, which face away from each other but towards the fixed support surfaces and which likewise are flat and, moreover, virtually semi-circular.
In practice, the movable support surfaces 41-45 are configured on an arc-shaped, in the example stepwise tapered edge portion 46 on the inner side of the holder part 4. This edge portion 46 thus forms the movable support portion and extends into and runs, under the rotational motion of the holder part 4, through a recess 47 at the front end 35 of the support arm 33.
The movable support surfaces 41-45 of the support mechanism 32 are thus arranged to rest against the fixed support surfaces 36-40 through contact with these both in the stationary state of the holder part 4 and during its rotation, when the movable support surfaces are allowed to slide against the fixed support surfaces. Depending on the force action upon the holder part 4, and also depending on tolerances, one or more of the support surfaces are in contact with one another. The important thing is that at least one movable support surface, at least while under load, can be in contact with a corresponding fixed support surface.
The sectional views in Figs. 3, 4 and 5, and the front view in Fig. 6, show the structure of the holder device in greater detail.
Fig. 7 shall illustrate a work bench 48, track, guide bar or equivalent in a bending machine for bending an object 3 such as a wire or wire blank by means of bending tools 49. A clamp or holder for the wire 3 and/or a gripping tool for securing the wire during its bending is/are shown with the reference notation 50. Such a clamp 50 steals space along the wire 3 and means, inter alia, that the wire cannot be subjected to a bending along a certain and significant length of the wire, especially if a holder, moreover, is arranged between the shown clamps 50 in order to secure the wire during the bending operation. In the figure, the holder device 1 according to the invention is shown schematically in order to illustrate that a use thereof prevents only a small length of the wire from being subjected to bending. As can be seen from the figure, the locking device 9 of the holder device 1 has a minimal width.
The machine in the example is thus of a type having a fixed centre holder 1 for the wire 3, for firstly securing and secondly rotating the wire about its longitudinal axis, and two wire holders 50, which are movable in the longitudinal direction of the wire and are integrated with the movable bending tools that move between 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.
Fig. 8 shows a wire 3 which has been subjected to bending 51 adjacent to the locking device 5 of the holder device 1, wherein that length of the wire which cannot be subjected to a bending is shown with the notation 1. A corresponding bending 52 in the use of commonly found tools and holders is illustrated in Fig. 6, wherein it can be seen that that length 1 of the wire 3 which cannot be subjected to a bending 52 is significant.
It will therefore be apparent and understood that a use of a holder device 1 according to the invention opens up possibilities for a fresh design approach and configuration of products with hopefully improved design, or manufacture of new products. Moreover, the device 1 has an operationally reliable and simple construction, which can be realized at low cost. Furthermore, it is easily accessible for possible maintenance and adjustment, and also for repair should this prove necessary. It is important, however, that bending 52 can be carried out in the immediate vicinity of the device 1, which occupies only a small length 1 of the wire 6. That bending 52 can be carried out in the vicinity of the 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.
The object 6 or the wire can be subjected to a bending by a plurality of tools along its extent in the machine, and two-dimensional bending. Through a radial rotation of the wire between bending operations by means of the device 1 or the holder 2 according to the invention, the wire can be bent in other directions or into a bent object extending in three dimensions. The wire can thus be set rotating one or more times during the machining operations and at a relatively large angle of rotation.
Without breaching the scope of the inventive concept, modifications of the device according to the invention would 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 movable support portion can have the shape of a recess or groove into which the fixed portion extends.

Claims

Device for holding an object, preferably an elongate object 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 and, where appropriate, for also rotating the object during the said work operations, wherein the device (1) comprises a holder part (4) having a seat (7) for the object (3) in which the object is held during the work operations, the holder part (4) being arranged rotatably about a centre of rotation (34) which corresponds or substantially corresponds with the axis for the object (3) in its extent in the seat (7), and in which the holder part (4) is supported in a fixed suspension device (2) by means of a motion-transmitting mechanism which is provided with bearing arms (17, 18) connected between a drive device (30) and the holder part via pivot points (21, 22, 24, 25, 27, 28) situated at a distance from the centre of rotation (34) so as to create a torque on the holder part (4) for its rotation, and in which holderpart (4) a locking device (5) is arranged to switch a locking member (9) between a securement position for the object in the seat and a release position, characterized in that a support mechanism (32) is arranged between the suspension device (2) and the holder part (4) on a level with the seat (7), and in that the support mechanism (32) has a fixed support arm (33) having fixed support surfaces (36-40) which interact with movable support surfaces (41-45) on a support portion movable together with the holder part.
Device according to claim 1, characterized in that at least certain of the movable support surfaces (41-43) of the movable support portion (46) have a circular-arc-shaped extent having a centre of curvature which coincides with the centre of rotation (34) of the holder part (4).
Device according to claim 2, characterized in that at least certain of the fixed support surfaces (36-40) of the fixed support portion (33) are uniform with corresponding movable support surfaces (41-43).
Device according to claim 3, characterized in that the movable support portion (46) is configured as part of a circular arc and is arranged to extend into a recess in the fixed support portion (33) for support and guidance therein.
Device according to claim 1, characterized in that the holder device (1) comprises a locking device (5), which is combined with or forms part of the holder part (4) or a body (6) incorporated therein.
Device according to claim 5, characterized in that the locking device (5) has a locking member (9), wherein the locking device (5) or the locking member (9) is arranged to be switchable between an open position and a closed position, wherein in the open position the seat (7) is arranged such that it is accessible and in the closed position the locking member (9) is arranged to secure or lock the object (3) in the holder part (4) or in its seat (7).
Device according to claim 6, characterized in that the locking member (9) has a locking lug (10) or equivalent, which is arranged to hold, lock and/or ensure the position of the object (3) in the seat (7) and, where appropriate, also to guide the object (3) into the intended position in the seat (7).
Device according to claim 2, 3 or 4, characterized in that the one ends of the bearing arms (17, 18) are combined with the holder part (4) or the body (6) and the other ends thereof are combined with a drive device (31), or a drive shaft or equivalent having the said drive device, wherein the bearing arms (17, 18) are arranged such that they can be mutually displaced in the holder device (1) whilst maintaining a mutual parallelism or parallel motion.