GB1590128A

GB1590128A - Tensioning device

Info

Publication number: GB1590128A
Application number: GB5269276A
Authority: GB
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1976-12-16
Filing date: 1976-12-16
Publication date: 1981-05-28
Also published as: FR2374247A1; FR2374247B1

Description

(54) TENSIONING DEVICE (71) We, LUCAS INDUSTRIES LIMITED, a British Company of Great King Street, Birmingham B19 2XF, England, do hereby declare this invention for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to a tensioning device and is particularly, though not exclusively, concerned with a tensioning device for tensioning wire being wound onto a support frame or former.

It is an object of the present invention to provide a tensioning device which can tension wire or other elongate filamentary material accurately to the required tension and which is of relatively simple construction.

According to the present invention, there is provided a tensioning device for elongate filamentary material, comprising a rotatable support, an inlet and an outlet in said support for said filamentary material, said outlet being aligned with said inlet, and a plurality of elongate tensioning members extending between said inlet and said outlet, said elongate tensioning members being disposed around an axis on which the inlet and the outlet lie in spaced apart relationship and being twisted together intermediate their ends so that, in use, the tensioning members frictionally engage around the surface of the filamentary material whereby a tensioning force is applied to the filamentary material whereby a tensioning force is applied to the filamentary material as it passes through the device.

Preferably, means are provided for ad justing the amount of twist of the elongate tensioning members whereby the tensioning can be varied to select the desired tension in use.

Most advantageously, the support in cludes first and second members to which respective ends of the tensioning members are secured, the first member is rotatable relative to the second member about said axis, and releasable means are provided for locking the first member relative to the second member.

The support of the tensioning device is rotatable so that, if the device is used for tensioning rotating filamentary material, it can be rotated so as to prevent or reduce relative rotation between the filamentary material and the elongate tensioning members.

The elongate tensioning members may be in the form of one or more lengths of elongate filamentary material, e.g. string elongate filamentary material, e.g. string or wire, and extending back and forth between said first and second members.

Also according to the present invention, there is provided winding apparatus for winding elongate filamentary material from a reel onto a support, said winding apparatus including a tensioning device as defined in any one of the last preceding five paragraphs.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is an axial sectional view of a tensioning device according to one example of the present invention, Fig. 2 is a schematic perspective view of one form of winding apparatus incorporating the tensioning device of Fig. 1, and Fig. 3 is a schematic perspective view of another form of winding apparatus including the tensioning device of Fig. 1.

Referring to Fig. 1, the tensioning device comprises a support frame 10 which is rotatable about its longitudinal axis and a multiplicity of runs of string 11 supported in the frame 10 in a manner to be described hereinafter.

The frame 10 comprises a pair of internally screw-threaded annular plates 12 and 13 which are axially aligned and which are secured in spaced apart relationship by a set of three spacer bars 14 (only two shown).

The frame 10 also includes first and second members 15 and 16 which are engaged in screw-threaded fashion in the screw-threaded bores in the respective an nular plates 12 and 13. The first and second members 15 and 16 have respective axial bores 17 and 18 therethrough.

The first and second members 15 and 16 are provided with respective annular flanges 19 and 20. Each flange 19, 20 has a series of angularly spaced bores (not shown) therethrough, the bores extending parallel to the longitudinal axis of the tensioning device.

It will be appreciated from the above, therefore, that the first and second members 15 and 16 are arranged with their axes on the axis of the tensioning device and are spaced apart on said axis. The runs of string 11 are formed by a single length of the string which is threaded through the bore in the respective annular flanges 19 and 20 to run back and forth between the flanges 19 and 20. Lock nuts 21 and 22 are provided on the respective members 15 and 16.

In use, wire 21 to be tensioned passes through the bore 17 which acts as an inlet, within the runs of string 11, and out through the tensioning device through the bore 18 which acts as an outlet.

Tension is applied to the wire 21 as it passes through the tensioning device by slackening the lock nut 21 and then rotating the first member 19 in a direction to move it to the left as viewed in Fig. 1.

With the second member 20 locked against rotation, rotation of the first member 19 to move it to the left as viewed in Fig. 1 will cause an intermediate portion 23 of the runs of string 11 to be twisted together around the wire 21 so that the string 11 engages the surface of the wire 21 whereby a frictional force is applied to the string 21 as it passes through the device. The tenioning force applied to the wire 21 by the tensioning device can be readily adjusted merely by adjusting the amount of twist of the string 11. The further the first member 19 is moved to the left as viewed in Fig. 1, the more it is rotated and the tighter the force applied by the string 11 on the wire 21 becomes. If desired, the second member 16 may be rotated as an alternative to or in addition to rotation of the first member 15.

Referring now to Fig. 2, the winding apparatus illustrated therein comprises a reel 30 carrying a supply of the wire 21 which is to be wound onto a support frame or former 31. In this embodiment, the wire 21 is wound onto the former 31 by means of a rotary flyer 32. In order to prevent the wire 21 from being twisted as it is wound onto the former 31, the whole of the reel 30 is itself mounted on a rotary support 33 for rotation about an axis of rotation which coincides with the axis of rotation of the rotary flyer 32. In this embodiment, the tensioning device (indicated at 34 in Fig. 2) is also rotated about its longitudinal axis which coincides with the axis of rotation of the flyer 32 and sup port 33. The angular velocity of the tensioning device 34 is arranged to be equal to and in the same sense as that of the support 33. In this manner, relative angular rotation between the tensioning device 34 and the wire 21 is avoided. The tensioning device 34 imparts consistently, the correct amount of tension to the wire 21 being wound on the former 31.

As can be seen from Fig. 1, the ends of the bores 17 and 18 are flared in order to reduce wear on the wire 21 and the string 11 is twisted around the wire 21 by rotation of the first member 19 in the same direction as the whole of the tensioning device 34 is rotated.

Referring now to Fig. 3 of the drawings, the winding apparatus illustrated therein is simpler than that illustrated in Fig. 2 in that the rotary flyer 32 is dispensed with and the former 31 is itself rotated about its longitudinal axis, the longitudinal axis of the former 31 being disposed at right angles to the axis of the wire 21. The reel 30 is not supported for rotation about the axis of the wire 21 but is merely freely rotatable to enable unreeling of the wire 21 therefrom. The tensioning device 34, al though rotatable, is not mounted for not rotated about the axis of the wire 21 in this embodiment.

Because of the manner in which the string 11 engages the wire 21, the Applicants have found that wear on the string 11 is suprisingly low so that replacement of broken string and readjustment thereof to maintain tension is suprisingly infrequent.

WHAT WE CLAIM IS:- 1. A tensioning device for elongate -filamentary material, comprising a rotatable support, an inlet and an outlet in said support for said filamentary material, said outlet being aligned with said inlet, and a plurality of elongate tensioning members extending between said inlet and said outlet, said elongate tensioning members being disposed around an axis on which the inlet and the outlet lie in spaced apart relationship and being twisted- together intermediate their ends so that, in use, the tensioning members frictionally engage around the surface of the filamentary material whereby a tensioning force is applied to the filamentary material as it passes through the device.

2. A tensioning device as claimed in claim 1, wherein means are provided for adjusting the amount of twist of the elongate tensioning members.

3. A tensioning device as claim in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. nular plates 12 and 13. The first and second members 15 and 16 have respective axial bores 17 and 18 therethrough. The first and second members 15 and 16 are provided with respective annular flanges 19 and 20. Each flange 19, 20 has a series of angularly spaced bores (not shown) therethrough, the bores extending parallel to the longitudinal axis of the tensioning device. It will be appreciated from the above, therefore, that the first and second members 15 and 16 are arranged with their axes on the axis of the tensioning device and are spaced apart on said axis. The runs of string 11 are formed by a single length of the string which is threaded through the bore in the respective annular flanges 19 and 20 to run back and forth between the flanges 19 and 20. Lock nuts 21 and 22 are provided on the respective members 15 and 16. In use, wire 21 to be tensioned passes through the bore 17 which acts as an inlet, within the runs of string 11, and out through the tensioning device through the bore 18 which acts as an outlet. Tension is applied to the wire 21 as it passes through the tensioning device by slackening the lock nut 21 and then rotating the first member 19 in a direction to move it to the left as viewed in Fig. 1. With the second member 20 locked against rotation, rotation of the first member 19 to move it to the left as viewed in Fig. 1 will cause an intermediate portion 23 of the runs of string 11 to be twisted together around the wire 21 so that the string 11 engages the surface of the wire 21 whereby a frictional force is applied to the string 21 as it passes through the device. The tenioning force applied to the wire 21 by the tensioning device can be readily adjusted merely by adjusting the amount of twist of the string 11. The further the first member 19 is moved to the left as viewed in Fig. 1, the more it is rotated and the tighter the force applied by the string 11 on the wire 21 becomes. If desired, the second member 16 may be rotated as an alternative to or in addition to rotation of the first member 15. Referring now to Fig. 2, the winding apparatus illustrated therein comprises a reel 30 carrying a supply of the wire 21 which is to be wound onto a support frame or former 31. In this embodiment, the wire 21 is wound onto the former 31 by means of a rotary flyer 32. In order to prevent the wire 21 from being twisted as it is wound onto the former 31, the whole of the reel 30 is itself mounted on a rotary support 33 for rotation about an axis of rotation which coincides with the axis of rotation of the rotary flyer 32. In this embodiment, the tensioning device (indicated at 34 in Fig. 2) is also rotated about its longitudinal axis which coincides with the axis of rotation of the flyer 32 and sup port 33. The angular velocity of the tensioning device 34 is arranged to be equal to and in the same sense as that of the support 33. In this manner, relative angular rotation between the tensioning device 34 and the wire 21 is avoided. The tensioning device 34 imparts consistently, the correct amount of tension to the wire 21 being wound on the former 31. As can be seen from Fig. 1, the ends of the bores 17 and 18 are flared in order to reduce wear on the wire 21 and the string 11 is twisted around the wire 21 by rotation of the first member 19 in the same direction as the whole of the tensioning device 34 is rotated. Referring now to Fig. 3 of the drawings, the winding apparatus illustrated therein is simpler than that illustrated in Fig. 2 in that the rotary flyer 32 is dispensed with and the former 31 is itself rotated about its longitudinal axis, the longitudinal axis of the former 31 being disposed at right angles to the axis of the wire 21. The reel 30 is not supported for rotation about the axis of the wire 21 but is merely freely rotatable to enable unreeling of the wire 21 therefrom. The tensioning device 34, al though rotatable, is not mounted for not rotated about the axis of the wire 21 in this embodiment. Because of the manner in which the string 11 engages the wire 21, the Applicants have found that wear on the string 11 is suprisingly low so that replacement of broken string and readjustment thereof to maintain tension is suprisingly infrequent. WHAT WE CLAIM IS:-

1. A tensioning device for elongate -filamentary material, comprising a rotatable support, an inlet and an outlet in said support for said filamentary material, said outlet being aligned with said inlet, and a plurality of elongate tensioning members extending between said inlet and said outlet, said elongate tensioning members being disposed around an axis on which the inlet and the outlet lie in spaced apart relationship and being twisted- together intermediate their ends so that, in use, the tensioning members frictionally engage around the surface of the filamentary material whereby a tensioning force is applied to the filamentary material as it passes through the device.

3. A tensioning device as claim in

claim 1, wherein the support includes first and second members to which respective ends of the tensioning members are secured, the first member is rotatable relative to the second member about said axis, and releasable means are provided for locking the first member relative to the second member.

4. A tensioning device as claimed in any preceding claim, wherein the elongate tensioning members may be in the form of one or more lengths of elongate filamentary material.

5. A tensioning device as claimed in claim 4, when appended to claim 3, wherein the tensioning members are formed by a single length of such material extending back and forth between said first and second members.

6. Winding apparatus for winding elongate filamentary material from a reel onto a support, said winding apparatus including a tensioning device as claimed in any one of claims 1 to 5.

7. A tensioning device substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawings.

8. Winding apparatus substantially as hereinbefore described, with reference to Fig. 2 or Fig. 3 of the accompanying drawings.