APPARATUS AND METHOD FOR FORMING SPRINGS

Abstract

A spring forming apparatus is shown generally at 200, in which metal wire 220 is fed from a supply (not shown) by feed rollers 230, via irregularity-effecting rollers 240 to a forming station 250. The forming station comprises a first deflector 260 and a second deflector 270. When the spring S is complete, it separates automatically from the rest of the wire 220 due to the presence of an irregularity 280, without the need for a cutter device.

Claims

1. A method of manufacturing a spring from a spring medium, the method comprising effecting an irregularity in a portion of the spring medium and thereafter deflecting the spring medium to cause it to form a spring, whereby the deflecting is arranged to cause a separation in the spring medium at the location of the irregularity.

2. A method according to claim 1, wherein the method comprises feeding the spring medium from a supply to a spring forming apparatus.

3. A method according to claim 1, wherein the method comprises effecting an irregularity in the spring medium which includes at least one partial cut, indent, nick, depression, deformity or weakness in the spring medium.

4. A method according to claim 1, wherein the method comprises effecting the irregularity in the spring medium using one or more rollers.

5. A method according to claim 1, wherein the irregularity is formed without halting the motion of the spring medium.

6. A method according to claim 1, wherein the irregularity is formed without slowing the motion of the spring medium.

7. Apparatus for manufacturing a spring from a spring medium, the apparatus comprising a feed device for feeding the spring medium and a spring forming device for forming a spring by deflecting the spring medium, wherein deflection by the spring forming device is arranged in use to create a separation in the spring medium at the location of a previously formed irregularity.

8. Apparatus according to claim 7, wherein the apparatus further comprises an irregularity forming device for forming an irregularity in the spring medium.

9. Apparatus according to claim 8, wherein the irregularity forming device is arranged to form an irregularity in the spring medium comprising at least one partial cut, indent, nick, depression, deformity or weakness in the spring medium.

10. Apparatus according to claim 8, wherein the irregularity forming device comprises one or more rollers.

11. Apparatus according to claim 7, wherein the spring medium comprises a supply of substantially unbent material to be formed into springs by deflecting the material so as to cause it to bend.

12. Apparatus according to claim 7, wherein the spring medium comprise metal wire.

13. Apparatus according to claim 7, wherein as a result of the irregularity, the spring medium is arranged to break by the deflecting action of the spring forming device, thereby to separate a formed spring from the rest of the spring medium.

14. A program for causing a device to perform a method of manufacturing a spring in according to claim 1.

15. Apparatus comprising a processor and a memory having therein computer readable instructions, the processor being arranged in used to read the instructions to cause the performance of a method according to claim 1.

16. A computer program product on a non-transitory computer readable storage medium, comprising computer readable instructions that, when executed by a computer, cause the computer to perform a method of manufacturing a spring according to claim 1.

17. A spring formed by the method of claim 1.

18. A spring formed by the apparatus of claim 7.

Description

[0028] A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which

[0029] FIG. 1 shows schematically a previously considered apparatus for forming springs;

[0030] FIG. 2 shows schematically an apparatus for forming springs in accordance with an embodiment of the present invention;

[0031] FIG. 3 shows a portion of spring medium containing an irregularity; and

[0032] FIG. 4 shows a pair of rollers for forming the irregularity of FIG. 3.

[0033] Turning to FIG. 2, this shows schematically a spring forming apparatus, generally at 200, according to an embodiment of the present invention. Metal wire 220 is fed from a supply (not shown) by feed rollers 230, via irregularity-effecting rollers 240 to a forming station 250. The forming station comprises a first deflector 260 and a second deflector 270, which work in substantially the same way as the deflectors of the previously considered spring forming station described above in relation to FIG. 1. However, there is no cutter in this embodiment. When the spring S is complete, it separates automatically from the rest of the wire 220 due to the presence Of an irregularity 280, as will be described below.

[0034] The irregularity-effecting pair of rollers 240 Comprises an upper roller 242 and a lower roller 244. Each roller has a channel 246 in which the wire 220 is conducted. Most of the time the rollers 240 are stationary and the wire 220 slides through the channels 246. When an irregularity is to be introduced, the rollers rotate and an anvil 248, located in the channel of the upper roller, comes to press against the wire, resulting in an irregularity 280 being introduced in the wire.

[0035] The timing and the motion of the rollers 240 is computer controlled, so that the position of the irregularity can be accurately specified.

[0036] FIG. 3 is a more detailed view of the wire 220 including the irregularity 280 formed by the rollers 240.

[0037] FIG. 4 shows the rollers 292 and 244. On the left is the lower roller of FIG. 2, showing the wire 220 in channel 246. To the right is the upper roller of FIG. 2, showing the irregularity-forming anvil 248. When an irregularity is to be formed the rollers 242 and 244 rotate and the anvil 248 presses the wire against the channel 246 of the lower roller. This causes a feature 280, such as is shown in FIG. 3, in a precisely determined place.

[0038] As the wire progresses towards the spring forming station 250 the feature 280 will eventually encounter the first deflector 260. When this happens the wire will break cleanly, so that the spring S, formed in advance of the feature 280, will separate from the rest of the wire 220. This is because the presence of the irregularity 280 concentrates the stresses in the wire when it experiences bending forces.

[0039] No cutter is needed, and therefore no slowing, much less a halt, of the feed is necessary. This allows for springs to be manufactured at a greater rate.

[0040] As a consequence, the heavy and expensive feed rollers. currently used in the apparatus shown in FIG. 1 are no longer needed.

[0041] Other arrangements for forming the irregularity can be used. For example, in another embodiment (net shown) the wire car be pressed between two opposed irregularity-forming anvils, or between one anvil on one roller and a pair complimentary supports on the other roller, for example. Furthermore, whilst the example of the irregularity 280 above is a V-shape, it will be understood that the shape and/or depth of the irregularity can be different.

[0042] An adjustment can be made for different diameters of wire by altering the pressure applied by the rollers 240 and/or the distance of the anvil feature or features 24S from the wire.

[0043] The timing of the irregularity forming operation can be controlled precisely by controlling the operation of the rollers 240, or just the single roller 242 in the example illustrated.

[0044] The irregularity need not be formed using one or more rollers. Other mechanical means may be employed to effect the weakness in the wire. Indeed, the means for making the irregularity need not be mechanical. An energy source, such as an electrical arc or a laser, could also be used to introduce the weakness in the wire al a predetermined location, for example.

[0045] Furthermore, whilst the example described above has the irregularity formed after (i.e. downstream of) the feed rollers, in another embodiment (not shown) it may be formed before (i.e. upstream of) the feed rollers.

[0046] In certain circumstances, the irregularities could be pre-formed on the wire, for example on another device, prior to introduction of the wire to the spring forming apparatus.

[0047] When combined with an alternative supply, that comprises for example a wire looped around the inside of a drum, from which the wire emerges substantially straight and under no tension, the present invention is particularly effective in increasing the speed of spring manufacture.

[0048] Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance, it should be understood that the applicant claims protection in respect of any patentable feature or combination of features referred to herein, and/or shown in the drawings, whether or not particular emphasis has been placed thereon.