GB2241449A

GB2241449A - Sandpaper block

Info

Publication number: GB2241449A
Application number: GB9004823A
Authority: GB
Inventors: Trevor William Robin Townsend
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-03-03
Filing date: 1990-03-03
Publication date: 1991-09-04
Also published as: GB9004823D0

Abstract

A sandpaper block for use with a continuous loop of sandpaper has two rigid-surfaced components 14, 16 each of which provides a part of the outer surface of the block, and a spring arrangement 28 between the two components which pushes the components apart. When a sandpaper belt or loop is in position around the components, the spring arrangement tensions the belt, and the rigid surfaces of the components provide a support for the sandpaper. <IMAGE>

Description

SANDPAPER BLOCK This invention relates to a sandpaper block to be held in the hand and to support a piece of sandpaper.

It is known to use an endless belt of sandpaper which is put into tension by a spring device inserted inside the belt. A tool of this type is shown in US patent 4688356.

However a sandpaper tool of this type does not provide the necessary rigidity of support for the sandpaper, because the component which is supporting the sandpaper is also the component which provides the resilience to tension the sandpaper.

In this specification, the term "sandpaper" is used to include all types of abrasive belt material, whatever the actual abrasive medium may be on the face of the belt.

According to the invention, there is provided a sandpaper block having a substantially continuous outer sandpapersupporting surface and comprising two rigid components each providing a part of the outer surface of the block, the components being guided for movement towards and away from one another and being biased apart by a spring arrangement.

The separation of the spring function from the sandpapersupporting surface means that the sandpaper-supporting surface can be rigid to provide a solid firm backing surface to the sandpaper.

The block may be generally rectangular in configuration, with the two parts being roughly of equal size.

Alternatively one or both parts may have a shaped end to provide a different contour to the sandpaper surface.

The two components are preferably moulded from plastics material and may have a hollow interior, or an interior stiffened by internal moulded webs. However the external surface of each component where it supports the sandpaper will be continuous.

The components may clip together so that when the sandpaper belt is removed, the components remain attached to one another. The two components may have overlapping wall portions so that substantially no part of the belt is unsupported.

The spring biasing the two components apart may be a leaf spring or a pair of leaf springs. The two components can be guided for relative movement by pins on one component which extend into corresponding sockets in the other component to allow relative longitudinal movement.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a perspective view of a sandpaper block in accordance with the invention with a sandpaper belt shown beside the block; Figure 2 is a transverse cross section through the block of Figure 1 with a belt of sandpaper thereon; and Figure 3 is a longitudinal cross section through the block of Figure 1.

Figure 1 shows a block generally designated 10 and a belt of sandpaper 12 for use with the block. The dimensions of the block and of the sandpaper belt will be chosen so that when the two parts of the block are compressed, the block can be inserted within the belt 12, and when the two halves are released, the belt will be placed in tension.

The block has a first component 14 and a second component 16. The component 14 has sandpaper-supporting surfaces 18,20 and the component 16 which has a curved end has a single sandpaper supporting surface 22 extending around the end of the block. The side faces 24 and 26 of the two components are shown in the drawings as being flat and continuous. However these side faces are not directly involved in providing support to the back face of the sandpaper and they can therefore be made in any convenient form. In particular they may include recesses to provide improved gripping by the hand of the user, and/or they may include a mechanism for locking the two halves in a compressed position so that the block can be inserted in the belt 12.The components 14 and 16 can be constructed in any way known to those skilled in the art of plastics moulding, provided that the faces 18,20,22 (and the corresponding faces which are not visible in Figure 1) are continuous and provide sufficient support to the back face of the sandpaper to ensure that the sandpaper maintains a flat configuration.

The width of the block 10 will normally be the same as that of the belt 12.

In order to bias the components 14 and 16 apart, leaf springs 28 are fitted between opposing internal faces of the two components as shown in Figures 2 and 3. To provide a guiding function, the component 16 has projecting pins 30 which extend into corresponding recesses 32 in the component 14. Furthermore the component 16 has extended side walls 34 which extend over part of the component 14 and which have snap-locking fitments 36 at their ends to clip to and lock in transverse grooves 38 in the component 14.

In use, the two components 14 and 16 are forced together against the resilience of the leaf spring 28, and the block is then inserted in the belt 12. A lock mechanism may be fitted to hold the components in their forced together position during insertion into the belt. The lock can then be released after insertion. When the components of the block are released inside the belt, the springs 28 will push the two components apart so that they put the belt 12 into tension. The block is then ready for use.

This invention provides a block which will securely hold a piece of sandpaper. Because the sandpaper is in the form of a belt, if a particular part becomes worn, then it is possible to rotate the belt on the block so that a different part of the sandpaper falls on the part of the block where most wear is being experienced. For example, the right angled corners at the bottom end of the component 14 are likely to experience considerable wear, but it is a simple matter to compress the block and then to turn the belt around a little way until a fresh piece of sandpaper lies adjacent these corners. The rounded top end of the component 16 allows non-flat surfaces to be sandpapered.

However shapes other than the simple rounded shape shown in the drawing can be used or a simple rectangular shape can be used.

The invention is not limited to the type of springs 28 which are shown in the drawings, neither is the method of guiding shown in the drawings intended to provide any limitation, and those skilled in the art will be able to devise alternative but functionally equivalent arrangements.

It is however important that the belt should be supported over all of its surface, and therefore the narrow gap between the components 14 and 16 which appears at 40 should be kept as small as possible.

Claims

1. A sandpaper block having a substantially continuous outer sandpaper-supporting surface and comprising two rigid components each providing a part of the outer surface of the block, the components being guided for movement towards and away from one another and being biased apart by a spring arrangement.

2. A sandpaper block as claimed in Claim 1, wherein the block is generally rectangular in configuration.

3. A sandpaper block as claimed in Claim 1, wherein one or both parts has a shaped end to provide a shaped contour to the sandpaper surface.

4. A sandpaper block as claimed in any preceding claim, wherein the two components are moulded from plastics material and have hollow interiors.

5. A sandpaper block as claimed in any one of Claims 1 to 3, wherein the two components are moulded from plastics material and have interiors stiffened by internal moulded webs.

6. A sandpaper block as claimed in any preceding claim, wherein the two components are moulded separately

7. A sandpaper block as claimed in any preceding claim, wherein the components clip together so that when the sandpaper belt is removed, the components remain attached to one another.

8. A sandpaper block as claimed in Claim 7, wherein the two components have overlapping wall portions so that substantially no part of the belt is unsupported.

9. A sandpaper block as claimed in any preceding claim, wherein the spring biasing the two components apart is a leaf spring or a pair of leaf springs.

10. A sandpaper block as claimed in any preceding claim, wherein the two components are guided for relative movement by pins on one component which extend into corresponding sockets in the other component to allow relative longitudinal movement.

11. A sandpaper block substantially as herein described with reference to and as shown in the accompanying drawings.