GB2258536A

GB2258536A - Method of testing the surface of an elongated piece of material and apparatus for use in the method.

Info

Publication number: GB2258536A
Application number: GB9117153A
Authority: GB
Inventors: Joseph Trevor Sidaway
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-08-07
Filing date: 1991-08-07
Publication date: 1993-02-10
Also published as: GB9117153D0

Abstract

Hardness testing apparatus for use in association with a continuous processing line comprises a body (11) mounted for upward and downward movement and urged upwards into a rest position by a spring (15). An indenter (13) is carried on the body to engage an upper face of strip (17) in the processing line. A support (14) is mounted on the body at a position below the indenter and can be raised relative to the body, e.g. by a screw-and-nut drive, to drive the body downwards and bring the indenter into engagement with the strip (17) to be tested. <IMAGE>

Description

Title: Method of testing the surface of an elongated piece of material and apparatus for use in the method.

Description of Invention From one aspect, the present invention relates to the testing of the surface of an elongated piece of material at a position on the material which lies in a predetermined path along which the material is moved during processing.

The invention has been devised primarily for use in testing the surface hardness of continuously processed material.

According to the first aspect of the invention, there is provided, adjacent to said predetermined path, testing apparatus comprising a support and a contact element, the support is moved towards a first face of the piece of material and into engagement with the first face to exert a force on the piece of material, said force is increased and the reaction to the force exerted by the support on said first face is applied to a carrier for the contact element to displace the carrier relative to the piece of material and thereby move the contact element into engagement with the piece of material at a second face thereof opposite to the first face, the apparatus is operated to test the material and the support and the contact element are subsequently separated from the piece of material.

During operation of the apparatus to test the material, longitudinal movement of the material relative to the contact element is avoided. This may be achieved by maintaining the material stationary in said path or by moving both the testing apparatus and the piece of material along the path.

The contact element is preferably separated from the second face of the piece of material by the action of biasing means which continuously biases the contact element away from the second face. In this case, during approach of the contact element to the first face of the piece of material, the action of the biasing means is overcome by increasing the force which the support exerts on the piece of material, and the biasing means maintains the support in contact with the first face of the piece of material during initial movement of the contact element from the second face of the material.

According to a second aspect of the invention, there is provided apparatus suitable for use in a method according to the first aspect and comprising a base, a body mounted on the base for movement relative thereto, a contact element on the body and a support for the piece of material to be tested, wherein the support is mounted on the body for movement relative thereto towards the contact element in the direction of movement of the body relative to the base and driving means is provided for driving the support relative to the body.

An example of apparatus embodying the second aspect of the invention and which is used in a method according to the first aspect of the invention will now be described, with reference to the accompanying drawing, wherein: FIGURE 1 shows diagrammatically apparatus in accordance with the invention, together with a piece of material which is to be tested and FIGURE 2 shows the apparatus of Figure 1 during testing of the piece of material.

The particular example of apparatus illustrated in the accompanying drawing is a hardness tester suitable for determining the Rockwell hardness of metallic materials. The apparatus comprises a base 10 which stands on a floor, a body 11 mounted on the base for pivoting relative thereto about a horizontal axis 12 adjacent to one margin of the body 11 and a contact element in the form of an indenter 13 mounted on the body at a position remote from the axis 12 so that the indenter moves upwardly and downwardly when the body undergoes limited pivoting relative to the base about the axis 12.The apparatus further comprises known means for mounting the indenter 13 in the body 11, moving the indenter relative to the body to form an indentation in material which is to be tested, means for determining the size of the indentation and, possibly, means for displaying and/or recording a dimension of the indentation in the material or the hardness of the material.

The apparatus shown in the drawing further comprises a support 14 which is mounted on the body 11 at a position below the indenter 13 for movement relative to the body towards and away from the indenter, that is to say upwardly and downwardly, with the apparatus oriented as shown in the drawing.

Drive means is provided for moving the support upwardly and downwardly relative to the body. For example, the drive means may comprise a screw and nut mechanism and an electric motor for driving this mechanism. Alternatively, an hydraulic device or a pneumatic device may be provided for moving the support relative to the body.

The apparatus further comprises yieldable biasing means 15 for urging the body 11 upwards relative to the floor and relative to the base 10. In the accompanying drawing, this biasing means is represented diagrammatically as a coiled compression spring. It will be understood that other forms of biasing means, for example an elastomeric spring or a pneumatic device may be used.

An abutment 16 is provided to limit upward pivoting of the body 11 relative to the base and thereby define a rest position of the body which is represented in Figure 1.

The apparatus is associated with a processing line for processing in a substantially continuous manner an elongated piece of material, for example a steel strip. The processing line may include means for rolling the strip 17. Since the particular process to which the strip is subjected does not form part of the present invention, equipment included in the processing line is not represented in the accompanying drawings.

When the body 11 is in the rest position and the support 14 is in a lowered position relative to the body 11, there is between the support and the indenter 13 a substantial gap within which the strip 17 can be received, without the strip contacting either the support 14 or the indenter 13. This condition of the apparatus is represented in Figure 1. Processing of the strip and consequent movement of the strip past the testing apparatus can take place without disturbance of the testing apparatus.

When the strip 17 is to be tested, processing is interrupted and the strip is brought to rest. The support 14 is then driven upwards relative to the body 11 to bring the support into engagement with a lower face of the strip 17.

Upward movement of the support relative to the body 11 is continued, thereby increasing the pressure exerted on the lower face of the strip by the support 14.

The reaction to this pressure moves the body 11 downwards about the axis 12 and compresses the spring 15. The indenter 13 moves downwards with the body 11 and the downward movement is interrupted when the indenter comes into engagement with the upper face of the strip 17. It will be noted that the support 14 is held in pressure contact with the strip 17 by the action of the spring 15. The indenter 13 is then moved relative to the body 11 to form an indentation in the strip 17. This operation of the testing apparatus is carried out in a known manner and the depth of the indentation is determined, to provide an indication of the surface hardness of the strip.

The drive means for the support 14 is then operated to move the support downwards relative to the body 11, thus allowing the spring 15 to extend, raise the body 11 and raise the indenter 13 from the strip 17. The body 11 moves upwards into engagement with the abutment 16 and then continued downward driving of the support 14 moves the support away from the strip 17 so that processing of the strip can be continued.

Operation of the apparatus to test the hardness of the strip 17 may be initiated automatically when the indenter 13 comes into engagement with the strip 17. It will be noted that the testing apparatus can be used with strips of varying thickness and that the apparatus automatically adapts to the thickness of the strip without prior adjustment of the apparatus.

Whilst we have described a hardness tester having an indenter as an example of apparatus which may be used in a method embodying the invention, it will be understood that other testing apparatus may be used. For example, the contact element may be adapted for testing an electrical property or a magnetic property of the strip 17. The method herein described ensures that the contact element is in a predetermined position relative to the strip, namely in engagement with one face of the strip, before the test is carried out.

In a case where the hardness of the strip is to be tested by means of an indenter, it is important that the face of the strip remote from the indenter is firmly supported. This is achieved by the apparatus herein before described. To facilitate good contact of the support 14 with the underside of the strip 17, the support 14 may be mounted for limited movement on a carrier which is driven upwards and downwards relative to the body 11. For example, limited rocking of the support relative to its carrier about one or more horizontal axes may be permitted.

Unless the testing apparatus can operate satisfactorily only when in a predetermined orientation, for example with an indenter moving downwards to form an indentation, the testing apparatus may be arranged in an orientation different from that represented in the accompanying drawing. For example, the support may engage one upright face of the piece of material to be tested whilst the contact element engages an opposite upright face.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawing, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed- result, as appropriate may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A method of testing the surface of an elongated piece of material at a position on the material which lies in a predetermined path along which the material is moved during processing, wherein there is provided, adjacent to said path, testing apparatus comprising a support and a contact element, the support is moved towards a first face of the piece of material and inter-engagement with the first face to exert a force on the piece of material, said force is increased and the reaction-to the force exerted by the support on said first face is applied to a carrier for the contact element to displace the carrier relative to the piece of material and thereby move the contact element into engagement with the piece of material at a second face thereof opposite to the first face, the apparatus is operated to test the material and the support and the contact element are subsequently separated from the piece of material.

2. A method according to Claim 1 wherein the contact element is separated from the second face of the piece of material by the action of biasing means which continuously urges the contact element away from the second face.

3. Apparatus suitable for use in a method according to Claim 1 and comprising a base, a body mounted on the base for movement relative thereto, a contact element on the body and a support for the piece of material to be tested, wherein the support is mounted on the body for movement relative thereto towards the contact element in the direction of movement of the body relative to the base and driving means is provided for driving the support relative to the body.

4. Apparatus according to Claim 3 further comprising yieldable biasing means for biasing the body towards a rest position relative to the base.

5. Apparatus according to Claim 3 or Claim 4 which is a surface hardness tester and wherein the contact element is an indenter.

6. Apparatus according to any of Claims 3 to 5 wherein the body is mounted for upward and downward movement relative to the base.

7. Apparatus according to any one of Claims 3 to 6 wherein the body is connected for pivoting relative to the base.

8. Apparatus substantially as herein described with reference to the accompanying drawing.

9. Any novel feature or novel combination of features disclosed herein or in the accompanying drawing.