GB2275883A

GB2275883A - Severing elongate members

Info

Publication number: GB2275883A
Application number: GB9303570A
Authority: GB
Inventors: Koorosh Khodabandehloo; Timothy Paul Fenton; Philip Mehl; Nickolas James Robberts; Adrian Waldock; Philip John Gittins
Original assignee: University of Bristol
Current assignee: University of Bristol
Priority date: 1993-02-23
Filing date: 1993-02-23
Publication date: 1994-09-14
Also published as: GB2275883A8; GB9303570D0

Abstract

An apparatus for severing elongate members 2 comprises a conveyor 4, carrying a number of cutting devices 22, driven around pulleys 8, 10, 12. A cutting device 22 comprises two levers (32, 34 Fig. 1) which are operated to sever the elongate member and to grip a severed portion. During closure of the levers 32, 34 of the cutting element 22, the cutting element 22 is travelling at substantially the same speed, and in substantially the same direction, as the elongate member 2. Conveyor 4 has gripping means 14 comprising a pair of jaws 16 which are adapted to grip a cutting element 22. When the gripping element 14 passes around the pulleys 8, 12, the jaws 16 separate to enable the cutting device to be 22 received into or released from the jaws 16. A first pulley 8 is adjacent a receiving station for transferring cutting elements 22 into the jaws 16, and a second pulley 12 is adjacent a discharge station for releasing cutting elements from the jaws 16. <IMAGE>

Description

2275883 SEVERING ELONGATE MEMBERS This invention relates to the severing

of elongate members.

In some manufacturing processes, elongate members such as cords are produced continuously, for example by an extrusion process. It is sometimes necessary to cut the continuously produced member into sperate portions of predetermined length, either for use or for further processing. Extruded members may be travelling at around 2 metres per second, and it is difficult to cut a member accurately when it is moving at such speed. Furthermore, once a portion has been severed from the travelling member, it is desirable to retain the severed portion for subsequent handling, and this requirement also adds complexity to the overall operation.

According to one aspect of the present invention, there is provided apparatus for severing an elongate member which is travelling in its lengthwise direction, and for gripping a severed portion of the elongate member, the apparatus comprising:

a cutting device; and drive means for driving the cutting device along a travel path in substantially the same direction and at substantially the same speed as the elongate member, the cutting device being actuable during movement along the travelling path to sever the elongate member, and having holding means for holding an end region of a resulting severed portion.

The travel path of the cutting device is preferably part of a closed loop. Thus, the drive means may comprise a continuous carrier such as a conveyor which runs in a closed loop around guide means.

The cutting device may be releasably connected to the conveyor. Means may be provided for supplying the cutting device to the conveyor at a supply position and for releasing the cutting device at a discharge position, the travel path lying between the supply and discharge positions. Means may be provided for receiving the cutting device and the respective severed portion held by it after release of the cutting device from the conveyor.

In a preferred embodiment, the elongate member travels vertically downwardly, with the result that the travel path of the cutter is also vertically downwards. After severing, each severed portion of the elongate member thus remains vertical.

The cutting device may comprise two cooperating parts which are movable relatively to each other to cut the elongate member and to grip the severed portion. A blade is thus provided on at least one of the parts, and preferably both parts have blades which cooperate in a scissor action to sever the elongate member. The holding means may comprise a resilient pad on at least one (and preferably on both) of the cooperating parts of the cutting device.

The two parts of the cutting device are preferably hinged together, and latch means may be provided for keeping the two parts in the closed position, with the holding means positioned to hold the severed portion.

According to another aspect of the present invention, there is provided transfer apparatus comprising an elongate resilient carrier provided with gripping means for gripping articles to be transferred, guide means being provided for guiding the carrier along a travel path, the gripping means comprising a pair of jaw elements which are spaced apart from each other on the carrier, whereby deflection of the carrier varies the spacing between the jaws, the travel path including a first region in which the spacing between the jaws is such as to enable an article to be gripped between them, and a second region in which the carrier is deflected to increase the spacing between the jaws to enable an article to be introduced between, or released from, the jaws. 5 The travel path of the carrier is preferably in the form of a closed loop. The carrier may comprise an elastomeric belt. In the second region of the travel path, deflection of the carrier may be caused by guiding the carrier around a roller. There may be two such rollers at different positions on the travel path, one of which is adjacent a supply of the articles, to enable them to be supplied sequentially to the jaws, while the other may be provided adjacent receiving means, for receiving the articles as they are released from the - jaws.

The guide means may include at least one further roller, which is larger in diameter than the rollers at the second regions, with the result that deflection of the carrier at the further roller is insufficient to cause articles retained by the jaws to be released.

In a preferred embodiment, the transfer apparatus is part of severing apparatus in accordance with the first aspect of the present invention, the articles to be transferred by the transfer apparatus then being constituted by the cutting device of the severing apparatus.

For a better understanding of the present invention and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which:

Figure 1 shows apparatus for severing an elongate member; Figure 2 shows, in schematic side view, the apparatus of Figure 1; Figure 3 shows a cutting device of the apparatus of Figure 1; and Figures 4.1 to 4.4 show the operation of gripping means of the apparatus of Figure 1.

Referring to Figure 2, an elongate member 2 in the form of a continuously extruded cord is conveyed downwardly, as indicated by an arrow A. A cutting device 22, carried on a conveyor belt 4, is driven over a travel path extending between two rollers 10 and 12 in the direction A at substantially the same speed as the cord 2. The relative speed between the cord 2 and the cutting device 22 is thus substantially zero.

An actuating device 30 is provided to actuate the cutting device 22 to sever the cord 2 to form a lower, severed portion 3 which, with the cutting device 22, is released from the conveyor belt 4 and transferred to a waiting station 28 for further processing or handling.

The belt 4 travels around a closed path which is def ined by guide means including the pulleys 10 and 12 and a third pulley 8. The pulleys 8 and 12 are of smaller radius than the pulley 10.

The belt 4 carriers gripping means 14 in the form of pairs of jaws 16. The jaws 16 are spaced apart in the travel direction of the belt 4. The spacing between the jaws 16 of each pair is sized to enable retention of the cutting device 22. A plurality of the cutting devices 22 is stored at a supply station 26. Feed means (not shown) is provided for feeding cutting devices sequentially to the conveyor belt 4. The supply station 26 is located adjacent the first pulley 30 8. A receiving station 28 is provided for receiving cutting devices from the conveyor belt 4. The receiving station 28 is provided adjacent the third pulley 12. 35 Between the second and third pulleys 10, 12 there is provided, adjacent the conveyor belt 4, an actuating rail 30.

The cutting device 22 is shown in more detail in Figure 3. The device 22 comprises two lever elements 32, 34 which in the embodiment shown in Figure 2 are connected by a hinge 36. However, the cutting device may be formed as a single moulding of plastics material having an internal hinge enabling relative movement between the two lever elements. Each lever element 32, 34 has an inward face 38, the inward faces cooperating with each other when the lever elements are brought together into engagement. Each inward face 38 is provided with a foam pad 40 and a cutting blade 42. The device 22 also has a latch 37, which comprises two cooperating members (shown diagrammatically), one on 15 the inward face 38 of each lever element 32, 34. The lever element 34 has a base portion 20 which is narrower than the main body of the element 34. The operation of the cutting machine will now be described. 20 Referring to Figures 1 and 2, the belt 4 is dr:ven around the pulleys 10, 12, 14 by drive means (not shown). This drive means may be responsive to the equipment which produces the cord 2 so as to ensure that the belt 4 is driven around the pulleys at a speed which corresponds to the speed at which the cord 2 moves. Means may be provided for maintaining a constant speed of the cord 2, even if its production rate fluctuates. The travel path of the belt 4 between the pulleys 10 and 12 is parallel to the end portion the cord 2.

When the belt 4 passes around the pulleys 8, 10, 12 the outer surface of the belt is stretched since it adopts an arcuate path of greater radius than that of the inner surface of the belt 4.

As can be seen in Figure 4, when the belt 4 passes around the pulleys, the jaws 16 open apart from each other and the spacing between them increases. As can be seen in Figure 4. 1, when the belt 4 passes around the pulley 8 of relatively small radius, the jaws tend to spread open, to provide a spacing denoted by Y1 between them. In Figure 4.2 the spacing between the jaws 16 when the belt 4 is straight (i.e. between pulleys) is denoted by Y2, which is smaller than spacing Y1. In Figure 4.3 the spacing between the jaws 16 is denoted by Y3, when the gripping member 14 is situated over the larger pulley 10. Deformation of the belt is less pronounced and consequently the jaws do not open out to such an extent.

In Figure 4.4 it can be seen that the radius of the pulley 12 is substantially the same as the radius of the pulley 8 and therefore the jaws 16 are opened relatively widely.

The spacing of the jaws 16 is designed such that the base portion 20 of the lever element 34 will be held between the jaws, by virtue of the resilient elasticity of the belt, when the gripping member is situated between the pulleys, or runs over the larger pulley 10. However, when the conveyor belt 4 passes around the smaller pulleys 8, 12 the spacing between the jaws becomes sufficiently large to enable the carrier element 18 to be inserted between or withdrawn from the jaws 16 relatively freely. Thus, the cutting device 24 may be inserted into or removed from the jaws 16 under the force of gravity alone.

Referring to Figure 2, the cutting devices 22 at the supply station 26 are controlled so that, as a pair of jaws 16 passes around the pulley 8, a cutting device is fed to the conveyor belt 4 and the base portion 20 of the lever member 34 is inserted into the space between the jaws 16. As the conveyor belt 4 passes over the pulley 8 and onto the linear section of the belt 4 between the first pulley 8 and the second pulley 10, the jaws are drawn together and resiliently retain the cutting device 22.

The lever elements 32, 34 of the cutter 22 are introduced onto the belt 4 in an open position, as shown in Figure 1, and remain in this position as the jaws 16 carrying the clip 24 pass around the pulley 10. The radius of the second pulley 10 is sufficiently large for the spacing of the jaws 16 to be insufficient to allow release of the cutting device 22. As the cutting device 22 passes around the pulley 10, it is moved by the belt into a position in which the lever member 34 runs close to the cord 2, as shown in Figure 1. As the cutting device 22 moves along the travel path between the pulleys 10 and 12, the lever element 32 engages with the guide element 30 which causes the lever element 32 to close. During this operation, the cutting edges 42 (shown more clearly in Figure 3) are brought together to cut the cord 2. At the same time, the foam pads 40 on the inward faces 38 of the two lever elements 32, 34 are also brought together to grip the severed portion 3 of the cord 2 immediately below the cut. The lever elements 32, 34 are finally completely closed and the latching element 37 is engaged to secure the cutting device 22 in its closed position. The device 22, now holding the severed portion 3 of the cord 2 progresses towards the pulley 12. As the belt 4 passes around the third pulley 12, the jaws 16 of the gripping member 14 open, as shown in Figure 4.4. Under the force of gravity, the cutting device 22 falls out of the jaws 16. The cutting device 22, holding the severed portion 3 of the cord 2, then passes to the receiving station 28. The severed portion 3 of the cord 2 can then be passed on for further processing, e.g. drying or curing, while supported by means of the cutting device 22.

The length of each severed portion 3 is determined by the distance between adjacent pairs of jaws 16. Thus, by varying the positions of the pairs of jaws 16 on the belt 4, the lengths of the severed portions 3 can be varied.

The transfer of severed portions between the belt 4 and the receiving station 28, and their support by the cutting devices 22 at the receiving section, is preferably such as to maintain the severed portions 3 straight and vertical, to avoid any distortion of them.

Claims

1. An apparatus for severing an elongate member which is travelling in its lengthwise direction, and for gripping a severed portion of the elongate member, the apparatus comprising:

2. An apparatus as claimed in claim 1, in which the travel path of the cutting device is part of a closed loop.

3. Apparatus as claimed in claim 2, in which the drive means comprises a conveyor which forms a closed loop around guide means. 20

4. An apparatus as claimed in claim 3, in which the cutting device is releasably connected to the conveyor.

5. An apparatus as claimed in claim 3 or 4, in which means is provided for supplying the cutting device to the conveyor at a supply position and for releasing the cutting device at a discharge position, the travel path lying between the supply and discharge positions.

6. An apparatus as claimed in claim 5, in which the supply means comprises storage means for storing a plurality of the said cutting devices for sequential supply to the conveyor.

7. An apparatus as claimed in claim 5 or 6, in which means is provided for receiving the cutting device and the respective severed portion held by it after release of the cutting device from the conveyor.

8. An apparatus as claimed in any preceding claim, in which the elongate member travels vertically downwardly, and the cutting device travels vertically downward along the travel path.

9. An apparatus as claimed in any preceding claim, in which the cutting device comprises two cooperating parts which are movable relatively to each other to cut the elongate member and to grip the severed portion.

10. An apparatus as claimed in claim 9, in which each of the parts is provided with a blade, the blades cooperating to sever the elongate member.

11. An apparatus as claimed in claimed in claim 9 or 10, in which at least one of the cooperating parts has a resilient pad for engagement of the severed portion of the elongate member when gripped between the cooperating parts of the cutting device.

12. An apparatus as claimed in any one of claims 9 to 11, in which the two cooperating parts are hinged together, latch means being provided for retaining the two parts in a closed position thereby to'grip the severed portion of the elongate member.

13. An apparatus as claimed in any one of the preceding claims, in which means is provided for displacing the elongate member at a substantially constant speed, at least in the region adjacent the travel path of the cutting device.

14. Transfer apparatus comprising an elongate resilient carrier provided with gripping means for gripping an article to be transferred, guide means being provided for guiding the carrier along a travel path, the gripping means comprising a pair of jaw elements which are spaced apart from each other on the carrier, whereby deflection of the carrier varies the spacing between the jaws, the travel path including a first region in which the spacing between the jaws is such as to enable the article to be gripped between them, and a second region in which the carrier is deflected to increase the spacing between the jaws to enable the article to be introduced between, or 5 released from, the jaws.

15. Transfer apparatus as claimed in claim 14, in which the travel path of the carrier is in the form of a closed loop.

16. Transfer apparatus as claimed in claim 14 or 15, in which the carrier comprises an elastomeric belt.

17. Transfer apparatus as claimed in any one of claims 14 to 16 in which deflection of the carrier in the second region of the travel path is caused by guiding the carrier around a roller.

18. Transfer apparatus as claimed in claim 17, in which there are two of the said second regions, at different positions on the travel path, a said roller being provided at each of the second regions, one of the rollers being adjacent means for supplying the article to the jaws, and the other roller being adjacent receiving means, for receiving the article as it is released from the jaws.

19. Transfer apparatus as claimed in claim 18, in which the guide means includes at least one further roller, which is larger in diameter than the rollers at the second regions of the travel path, such that deflection of the carrier at the further roller is insufficient to cause the article retained by the jaws to be released.

20. An apparatus for severing an elongate member as claimed in any one of claims 1 to 13, including transfer apparatus as claimed in any one claims 14 to 19, the article to be transferred by the transfer apparatus comprising the cutting device.

21. An apparatus for severing an elongate member substantially as described herein with reference to, a 1 0 0 and as shown in, the accompanying drawings.