GB2289068A

GB2289068A - Apparatus and method for testing fabrics

Info

Publication number: GB2289068A
Application number: GB9509044A
Authority: GB
Inventors: David Graham Lunn; Geoffrey James Fielding
Original assignee: Heal James H & Co Ltd
Current assignee: Heal James H & Co Ltd
Priority date: 1994-05-04
Filing date: 1995-05-04
Publication date: 1995-11-08
Also published as: GB9509044D0; GB9408860D0

Abstract

A sample holder 10 comprises a housing 11, a first gripping member 12, a second gripping member 13 and a stretching ball 14. The housing 11 and member 12 are of aluminium, member 13 is of steel and ball 14 is of precision ground rubber. The housing 11 shown separately in Figures 4a and 4b has at its upper end a hollow cylindrical portion 11a having a bushing 11b of oilite inserted therein which is arranged to engage a spindle 19 in a push fit. A portion (not shown) of fabric is pierced by pins of member 12 when the latter and member 13 are placed one on top of the other so that pins locate in holes 16 in member 13. The ball 14 is then placed onto the fabric over a hole 17 in member 13 and housing 11 and member 13 are screwed together to push ball 14 downwardly into hole 17 whereby the portion of fabric is stretched across ball 14 and may then be repeatedly rubbed on an abrading table 20. <IMAGE>

Description

APPARATUS AND METHOD FOR TESTING FABRICS Fabrics may be tested for wear by repeatedly rubbing a sample of the fabric with an abradant. In the case of most fabrics the sample of fabric is held in a sample holder which makes repeated rubbing movements over an abrading table.

However, fabrics which are usually stretched in use cannot be tested in the conventional way since the rate at which the unstretched sample wears is not sufficiently indicative of what will be the rate of wear of the fabric when stretched.

According to one aspect of the present invention there is provided a sample holder, for holding a sample of fabric to be tested, the holder comprising gripping means arranged in use to grip a portion of fabric to be tested, and stretching means arranged in use to exert a stretching force on the fabric.

Preferably, the gripping means comprises first and second gripping members arranged in use to grip a portion of fabric to be tested around a periphery of the portion.

The first gripping member may comprise at least one gripping blade.

Alternatively or additionally, the first gripping member may comprise one or more gripping pins.

The second gripping member may comprise a channel portion arranged in use to receive at least part of the first gripping member.

Alternatively or additionally, the second gripping member may comprise at least one hole arranged in use to receive at least part of the first gripping member.

Preferably, the first gripping member comprises a plurality of gripping pins and the second gripping member comprises a plurality of holes, the arrangement being such that in use the pins of the first gripping member are received at least partly in the holes of the second gripping member.

The gripping means may define a hole over which, in use, the portion of fabric to be tested is arranged to extend.

Preferably, the stretching means is arranged in use to co-operate with the hole so as to stretch the fabric across the hole.

In a preferred arrangement the hole is substantially circular.

Preferably, the stretching means has a convex surface. The stretching means may substantially comprise a ball. The ball may have one, and preferably two substantially flat surfaces. At least one of the flat surfaces may be arranged, in use, to bear against a portion of material to be tested.

In a preferred arrangement the stretching means comprises substantially a ball of rubber.

The holder may comprise a body portion arranged in use to be connected to the gripping means.

Preferably, the body portion is threadably mounted on the gripping means.

The body portion may be arranged in use to be connected to the gripping means so as to hold the first and second gripping members in engagement.

Preferably, the body portion is arranged in use to bear against the stretching member, so as to push the stretching member against the fabric sample, when the body portion is connected to the gripping means.

The sample holder may be arranged, in use, to engage a spindle. The spindle may engage the sample holder in such a way as to inhibit relative rotation between the sample holder and the spindle.

Preferably, the spindle is arranged, in use, to engage a mounting member, which mounting member is arranged, in use, to be mounted on a moving member in use.

The spindle and the mounting member may be arranged to engage each other in such a way as to inhibit relative rotation between the spindle and the mounting member.

Preferably, one of the spindle and mounting member is provided with a pin, and the other is provided with a slot, such that the pin engages the slot in use, to inhibit relative rotational movement between the spindle and the mounting member.

The mounting member may be arranged in use to be mounted on a testing machine such as is described in our co-pending U.K. Patent Application Number 2 256 716, the contents of which are incorporated herein by reference.

According to another aspect of the present invention there is provided a method of testing a portion of fabric, the method comprising gripping a portion of fabric in gripping means, and stretching the fabric with stretching means, the method further including abrading the stretched fabric with abrading means.

The method may include gripping the fabric with gripping means according to any statement herein.

The method may include stretching the fabric with stretching means according to any statement herein.

The invention may also include any combination of the features or limitations referred to herein.

An embodiment of the present invention will now be described by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 shows in cross-section a sample holder for holding a sample of fabric to be tested, according to one embodiment of the present invention, Figures 2a and 2b show respectively in a plan view and sectional view a first gripping member of the holder of Figure 1, Figures 3a and 3b respectively are sectional and plan views of a second gripping member of the holder of Figure 1, Figures 4a and 4b are respectively sectional and plan views of a housing portion of the holder of Figure 1, Figures 5a and 5b are side and plan views, respectively, of a spindle of the holder of Figure 1, Figures 6a and 6b are sectional and plan views, respectively, of an insert of the holder of Figure 1, Figures 7a and 7b are sectional and plan views, respectively, of a mounting member of the holder of Figure 1, and Figure 8 is a side view of a stretching ball of the holder of Figure 1.

Referring particularly to Figure 1, there is shown generally at 10 a sample holder comprising a housing 11, a first gripping member 12, a second gripping member 13 and a stretching ball 14. The housing 11 and first gripping member 12 are of aluminium, the second gripping member 13 is of steel and the ball 14 is of precision ground rubber. The housing 11 shown separately in Figures 4a and 4b has at its upper end a hollow cylindrical portion lla having a bushing llb of oilite inserted therein which is arranged to engage a spindle 19 in a push fit.

The first gripping member 12, shown separately in Figures 2a and 2b is a hollow cylinder having at spaced intervals around its lower surface a plurality of steel gripping pins 15.

The second gripping member 13, shown separately in Figures 3a and 3b is broadly cylindrical having a plurality of small holes 16 in an annular flange 13a at its lower edge. The holes 16 are arranged to receive the pins 15 of the first gripping means. The flange 13a defines a larger hole 17 having a bevelled edge 17a which is arranged to receive the ball 14.

Referring particularly to Figure 1, in use, a portion (not shown) of fabric to be tested is pierced by the pins 15 and held between the first gripping member 12 and second gripping member 13 when the first and second gripping members are placed one on top of the other so that the pins 15 locate in the holes 16. The ball 14 is then placed onto the fabric over the hole 17 and the housing 11 is screwed onto the second gripping member 13 by means of screw threads 11c comprising a brass insert shown separately in Figures 6a and 6b. As the housing 11 and second gripping member 13 are screwed together the ball 14 is pushed downwardly into the hole 17 and the portion (not shown) of fabric is stretched across the bevelled edge 17a of the second gripping member 13 and across the ball 14. The ball 14 is shown separately in Figure 8, and has two flat portions 14a and 14b machined on it. The upper portion 14a is arranged, in use, to bear against the housing 11. The lower portion 14b is arranged, in use, to bear against the portion (not shown) of fabric to be tested.

A vent hole lld in the housing 11 may allow air to escape the bore of the housing when the spindle 19 is pushed in.

Figures 5a and 5b show the spindle 19 which has a flat portion 19a machined on one side thereof. A pin 19b projects outwardly from the spindle 19.

Figure 1 shows the holder 10 mounted on fabric testing apparatus 21 such as is disclosed in our copending U.K. Patent Application Number 2 256 716. The holder is mounted on the apparatus 21 by a mounting member 18 which is attached to the apparatus 21 by means of three countersunk screws 18a, 18b and 18c (shown in Figure 7b).

Figures 7a and 7b show separately the mounting member 18. The mounting member 18 which is of steel, has a hollow bore 18d which, in use, receives the spindle 19.

Inside the hollow bore 18d is an oilite bushing 18e which permits a close friction fit with the spindle 19.

On one side of the mounting member 18 is an elongate slot 18f arranged, in use, to engage the pin 19b of the spindle.

The testing apparatus typically comprises a weight (not shown) which acts downwardly on the spindle 19 to which the holder 10 is attached. The apparatus causes repeated movement of the holder over an abrading table 20.

The sample of fabric is therefore repeatedly rubbed on the abrading table either for a predetermined number of movements or until the threads break. Since the sample is stretched it is possible to obtain a test result for the resistance of the fabric to wear in conditions close to the those of actual use.

It has been found that a straight-line backwards and forwards motion of the fabric against the abrading table provides the most accurate representation of wear in the material. The flat portion 19a of the spindle 19 engages a corresponding flat portion (not shown) on the housing 11 to inhibit any rotation of the spindle with respect to the housing 11. In addition, the pin 19b on the spindle 19 which engages the slot 18f of the mounting member 18, inhibits any relative rotational movement between the spindle 19 and mounting member 18. Therefore, the desirable straight line motion may be achieved, particularly since even the ball 14 is inhibited from rotation, due to the machining of the flat areas 14a and 14b.

The above apparatus and method may thus be used to test accurately for wear fabrics such as are used in hose and socks, or any stretchable material.

It will be apparent to those skilled in the art that various modifications may be made to the invention without departing from its scope.

Claims

CLAIMS:

1. A sample holder for holding a sample of fabric to be tested, the holder comprising gripping means arranged, in use, to grip a portion of fabric to be tested and stretching means arranged, in use, to exert a stretching force on the fabric.

2. A sample holder according to claim 1, wherein the gripping means comprises first and second gripping members arranged, in use, to grip a portion of fabric to be tested around a periphery of the portion.

3. A sample holder according to claim 2, wherein the first gripping member comprises at least one gripping blade.

4. A sample holder according to claim 2 or claim 3, wherein the first gripping member comprises one or more gripping pins.

5. A sample holder according to claim 2, wherein the second gripping member comprises a channel portion arranged, in use, to receive at least part of the first gripping member.

6. A sample holder according to claim 2, wherein the second gripping member comprises at least one hole arranged, in use, to receive at least part of the first gripping member.

7. A sample holder according to claim 2, wherein the first gripping member comprises a plurality of gripping pins and the second gripping member comprises a plurality of holes, the arrangement being such that, in use, the pins of the first gripping member are received at least partly in the holes of the second gripping member.

8. A sample holder according to any of the preceding claims, wherein the gripping means defines a hole over which, in use, the portion of fabric to be tested is arranged to extend.

9. A sample holder according to claim 8, wherein the stretching means is arranged, in use, to co-operate with the hole so as to stretch the fabric across the hole.

10. A sample holder according to claim 8 or claim 9, wherein the hole is substantially circular.

11. A sample holder according to any of the preceding claims, wherein the stretching means substantially comprises a ball.

12. A sample holder according to claim 11, wherein the ball has at least one substantially flat surface.

13. A sample holder according to claim 12, wherein the flat surface is arranged, in use, to bear against a portion of material to be tested.

14. A sample holder according to any of the preceding claims, wherein the stretching means comprises substantially a ball of rubber.

15. A sample holder according to any of the preceding claims, wherein the holder comprises a body portion arranged, in use, to be connected to the gripping means.

16. A sample holder according to claim 15, wherein the body portion is threadably mounted on the gripping means.

17. A sample holder according to claim 2 and claim 15, wherein the body portion is arranged, in use, to be connected to the gripping means so as to the hold the first and second gripping members in engagement.

18. A sample holder according to claim 15, wherein the body portion is arranged, in use, to bear against the stretching member so as to push the stretching member against the fabric sample when the body portion is connected to the gripping means.

19. A sample holder according to any of the preceding claims, wherein the sample holder is arranged, in use, to engage a spindle.

20. A sample holder according to claim 19, wherein the spindle engages the sample holder in such a way as to inhibit relative rotation between the sample holder and the spindle.

21. A sample holder according to claim 19 or claim 20, wherein the spindle is arranged, in use, to engage a mounting member which mounting member is arranged, in use, to be mounted on a moving member in use.

22. A sample holder according to claim 21, wherein the spindle and the mounting member are arranged, in use, to engage each other in such a way as to inhibit relative rotation between the spindle and the mounting member.

23. A sample holder according to claim 22, wherein one of the spindle and mounting member is provided with a pin, and the other is provided with a slot, such that the pin engages the slot in use, to inhibit relative rotational movement between the spindle and the mounting member.

24. A sample holder substantially as herein described with reference to the accompanying drawings.

25. A method of testing a portion of fabric, the method comprising gripping a portion of fabric in gripping means and stretching the fabric with stretching means, the method further including abrading the stretched fabric with abrading means.

26. A method according to claim 25, including gripping the fabric with gripping means according to any of claims 1 to 24.

27. A method according to claim 25, including stretching the fabric with stretching means according to any of claims 1 to 24.

28. A method of testing a portion of fabric, the method being substantially as herein described with reference to the accompanying drawings.