GB2289304A - Half clamp pressure element - Google Patents

Abstract

A clamping tool element which comprises a body (12), means (28) for applying pressure to the body, and at least two feet (14) on the body for contacting the surface to be clamped. That is, in its simplest form, the tool of the invention has at least two feet to spread the load. Preferably, it will have a greater number than two, with four and six footed versions being especially preferred. The tool of the invention may be provided with its own means to apply pressure or may be used in conjunction with a conventional G-clamp. <IMAGE>

Description

CLAMPING TOOL This invention relates to a clamping tool and in particular relates to a clamping tool for clamping articles together, for example when joining them with adhesive.

Clamps are used in a number of craft and DIY applications particularly but not exclusively in connection with working with wood. With the availability of so many good quality wood glues there is less need to rely on joinery screws or nails to join two pieces of wood together. The main disadvantage of using glues or adhesives is that the join is not immediate and the pieces have to be held in position while the glue sets.

Another problem is that the glue may act as a lubricant allowing the pieces to move relative to one another. Only by applying sufficient pressure to expel the excess glue and then maintaining that pressure can a close and accurate join be made.

Currently the most used clamp in such applications is the Gclamp. A problem with the G-clamp is that the pressure is delivered to a single point, which is not ideal where it is intended to make a join that is large in area or elongated.

The normal solution to this is to use more than one clamp, or use an additional baton as a 'spreader'. However in practice it is difficult to keep everything in place while the clamp is tightened. Also, it is sometimes necessary to exert an equal pressure across the surface and this is also difficult to achieve when using more than one G-clamp.

The invention seeks to provide a clamping tool improved in the above respects.

According to the present invention there is provided, in its broadest form, a clamping tool which comprises a body, means for applying pressure to the body, and at least two feet on the body for contacting the surface to be clamped.

That is, in its simplest form, the tool of the invention has at least two feet to spread the load. Preferably, it will have a greater number than two, with four and six footed versions being especially preferred. The tool of the invention may be provided with its own means to apply pressure (as will be described more fully hereinafter) or may be used in conjunction with a conventional G-clamp.

A preferred feature of the clamping tool of the invention is that the point of pressure on the tool body is applied as close to the working surface contacted by the feet. This has two distinct advantages: firstly, the amount of travel of the Gclamp or other clamping means is increased allowing a greater variability in the thickness of the object to be clamped; and, the stability of the device is increased greatly as there is a very much reduced tendency for the tool to over-balance when the pressure is applied.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figures l(a)-(c) show diagrammatically a side, bottom and top view of one embodiment of a tool in accordance with the invention; Figures 2(a)-(c) are similar views of a form of the tool complementary to that shown in figure 1; Figures 3(a)-(c) diagrammatically illustrate an arm and track arrangement for use with the embodiments of figures 1 and 2; Figures 4(a)-(d) illustrate a similar embodiment to figures 1 and 2 for use with a G-clamp Figure 5 illustrates a spreader; Figure 6 illustrates a variant with greater depth of adjustment; Figures 7(a)-(c) illustrate a variant on figure 1.

Figures 8a and 8b illustrate a simplified form of the embodiment of figure 1; and Figures 9(a)-(d) illustrate a simplified form of the embodiment of figure 2.

Referring to the drawings, and in particular figure 1, a clamping tool in accordance with one embodiment of the invention generally designated 10 is illustrated. The tool 10 has a body 12 and two pairs of feet 14. Each pair of feet 14 is mounted on an arm 16 which in turn is tiltably mounted on an axle 18 in a boss 20 itself rotatably attached to the end of the body 12 on an axle 22. The arm 16 can therefore both rotate and tilt with respect to the body 12.

The central portion 24 of the body 12 is designed to receive an arm 26 (described more fully in connection with figure 3 below) as well as a threaded rod 28 having a tommy bar 30 to enable it to be turned.

The arm 26 is illustrated more fully in figure 3 from which it can be seen that the arm is mounted on a track 32 along which it can slide. A counterpart arm 26a, described more fully hereinafter, is also mounted on the track 32. The arm 26 makes contact with the track at points 34 and 36 such that by tilting the arm towards its counterpart 26a it can move freely along the track and when pressure is exerted at the end of the arm the opposing pressures applied to the track at points 34 and 36 lock it in place. A spring 38 lightly holds the arms in place while they are adjusted.

The arm 26 has a threaded bore 40 at its distal end. It is this end of the arm 26 which enters the central portion 24 of the body 12 and the bore 40 receives the threaded rod 28.

The latter is held loosely in contact with the body 12 by means of a captive washer 42.

A pair of tools 10 mounted on arms 26 on track 32 may be used to clamp opposing sides of an article, e.g. while it is being glued. The article is placed between the tools 10 and the arms 26 are pushed towards one another until the article is loosely gripped. Operation of the tommy bar 30, thereby turning the rod 28, urges each tool 10 inwardly from the threaded bore 40 thereby applying pressure through the feet 14 to the article being gripped. The feet can tilt or rotate to take up the shape of the article to which pressure is to be applied.

While two tools as illustrated in figure 1 can be used, it is only necessary to have clamping means associated with one such tool. In this case the other may be as illustrated in figure 2, where like numerals are used to denote like parts. In this case, the central portion 24 of the body 12 has a transverse bore 44 to receive the distal end 46 of the arm 26a.

The latter is retained in place by means of a circlip (not shown in Figure 2 but illustrated at 49 in Figure 9(c)) which is retained in a groove 48 thereby locking the body 12 to the arm 26a. The complete tool in this embodiment will comprise one track 32, one arm 26, one arm 26a, one tool 10 as illustrated in figure 1 and one tool 10 as illustrated in figure 2. Operation is as described above.

While the embodiments of figures 1 and 2 have one or more clamping means in-built in the form of the threaded rod 28, it is equally possible to provide a tool of the invention for use with a conventional G-clamp. This is illustrated in figure 4 in which, once again, like numerals are used for like parts.

The central portion 24 of the body 12 in figure 4(a) is designed to receive the upper portion of a G-clamp. The corresponding central portion 24 in figure 4(d) is designed to receive the screw of a conventional G-clamp and the orifice 50 is large enough to receive the screw and captive washer of a conventional G-clamp. Where the body of the G-clamp makes contact with the body 12, a small projecting ridge 52 acts as a fulcrum to distribute the force exerted by the G-clamp equally to both ends of the body 12. An optional spreader as illustrated in figure 5 may be provided for the screw portion of the G-clamp if it is only necessary to apply the spread force of the tool of the invention to the upper portion of the article to be gripped. Figure 5 may then be used a simpler alternative to figure 4(d) for the other surface.

Turning now to figure 6, there is illustrated a similar tool to figure 1 in which a much greater range of adjustment is possible by means of the central portion 24 of the body 12 being considerably elongated to receive a threaded screw of much greater length (e.g. five times the length) of that in figure 1. This embodiment is useful where a much greater range of travel of the tool is required.

Figure 7 illustrates a variant on figure 1 in which no rotation of the arm 16 is required, all the feet 14 being permanently in line. This embodiment is useful for relatively narrow elongated joins. A tilting action at 18 is provided as before, which enables curves to be accommodated.

Figures 8 and 9 illustrate simplified versions of the embodiment shown in figures 1 and 2 in which only a single pair of feet is provided in each case. In figure 8, the body 12a is considerably foreshortened and carries feet 14 directly attached to it without the intermediary of the tiltable arm 16.

Similarly, in figure 9, the feet 14 are directly attached to a foreshortened body. The embodiments of figures 1, 2, 4 and 6 can also have arms 16 replaced by tripod shaped arms each of which carries three feet 14 or such greater number as may be desired further to spread the load.

It will be noted that the point at which pressure is applied in all the embodiments is at the lower part of the central portion 24 as close as possible to the working surface of the article contacted by the feet. This ensures stability and enabled the greatest range of adjustment to be obtained.

The tool of the invention provides a simple and efficient way of spreading the load applied to an article to be joined, e.g.

by gluing, and is superior to a conventional G-clamp used alone. A single point of pressure may be applied to 2, 4, 6 or more points spread over the article to be joined.

Moreover there is a reduced rotational effect on tightening the means for clamping resulting in less likelihood of the layers slipping with respect to one another as the device is tightened, again in contrast to a conventional Clamp.

In addition, the invention provides a system having great flexibility, allowing the user to choose from a range of different options to select the tool combination ideal for a particular job. In particular, apart from the interchangeability of the tool bodies 12, the track 32 can be supplied in varying lengths suitable for different end-uses.

The overall versatility of the system is thus very great.

Claims (8)

1. A clamping tool which comprises a body, means for applying pressure to the body, and at least two feet on the body for contacting the surface to be clamped.

2. A clamping tool as claimed in claim 1 having a greater number than two feet.

3. A clamping tool as claimed in claim 2 having four feet.

4. A clamping tool as claimed in claim 2 having six feet

5. A clamping tool as claimed in any of claims 1 to 4 having its own means to apply pressure.

6. A clamping tool as claimed in any of claims 1 to 4 adapted for use in conjunction with a conventional Clamp.

7. A clamping tool as claimed in any of claims 1 to 6 wherein the point of pressure on the tool body is applied as close as possible to the working surface contacted by the feet.

8. A clamping tool as claimed in claim 1 substantially as hereinbefore described with reference and as illustrated in the accompanying drawings.

8. A clamping tool as claimed in claim 1 substantially as hereinbefore described with refernece and as illustrated in the accompanying drawings.

Amendments to the claims have been filed as follows 1. A clamping tool which comprises a body, a single means for applying pressure to the body, and at least two feet on the body for contacting the surface to be clamped and spreading the applied pressure.

2. A clamping tool as claimed in claim 1 having a greater number than two feet.

3. A clamping tool as claimed in claim 2 having four feet.

4. A clamping tool as claimed in claim 2 having six feet 5. A clamping tool as claimed in any of claims 1 to 4 having its own means to apply pressure.

6. A clamping tool as claimed in any of claims 1 to 4 adapted for use in conjunction with a conventional G-clamp.

7. A clamping tool as claimed in any of claims 1 to 6 wherein the point of pressure on the tool body is applied as close as possible to the working surface contacted by the feet.