GB2392640A

GB2392640A - Fast clamping device

Info

Publication number: GB2392640A
Application number: GB0220552A
Authority: GB
Inventors: Simon Halsey
Original assignee: Bath Institute of Medical Engineering Ltd
Current assignee: Bath Institute of Medical Engineering Ltd
Priority date: 2002-09-04
Filing date: 2002-09-04
Publication date: 2004-03-10
Anticipated expiration: 2022-09-04
Also published as: GB2392640B; GB0220552D0

Abstract

A device that can clamp around items of varying thickness initially having a clamping force provided by a light spring 6 that moves the sliding element 5 of the clamp. This clamping force can then be increased by applying a load to the clamp body 1 which in turn compresses a leaf type spring 2 between the clamp body 1 and one side of the clamped item. As the leaf type spring 2 is compressed the sliding element 5 moves up the shaft 3 under the action of the light spring 6 and maintains contact with the other side of the item being clamped. Upon removal of the load the sliding element 5 maintains its position and thus the high clamp force is maintained.

Description

Fast Clamping Device ' . This invention relates to a clamping mechanism that can be easily clamped onto surfaces of varying thickness. Clamps are available wherein the thickness of the surface to be clamped to is accommodated with a screw type arrangement. An example of such a device is the (j-clamp. Another type of clamp uses a sliding element with a hole through it that slides on a shaft. The load on the element is offset from the point of sliding and so the hole grips on Ihe shaft. There are also combinations of these two types of clamp. These clamps require two hands clamp effectively and the screw part of the clamp needs to be turned a considerable number of times to accommodate surfaces of varying thickness. According to the present invention there is provided a mechanism that consists of a sprung loaded element sliding on a shaft at the top of which is a flat surface the underside of which is attached another stiff spring material, for example sprung steel sheet. The sprung loaded element clamps on one side of the surface to be clamped to. The top spring material contacts the other side of the surface. The sprung loaded element can be slid down the shaft against the force of the spring to accommodate thicker surfaces. Once the sprung loaded element and the top spring material are in contact with either side of the surface the flat surface can be pushed down, in turn compressing the stiff spring material underneath. This causes the spring under the sliding element to push the sliding element up and due to the offset force on the end of the sliding element, the hole catches on the shaft and it remains in its new position. This means that the clamp force is approximately equal to the force applied when the flat surface is pushed down. The clamp can then be released by pressing the sliding clamp element down. A specific embodiment of the invention will now be described by way of an example with reference to the accompanying drawings in which:- Figure 1 shows an isometric of the clamp with the moving element in mid-position. Figure 2 shows in side profile of the clamp with the moving element in midposition. figure 3 (a) shows the clamp front on having been put around a surface (b) shows the top of the clamp being pushed down, flattening the profiled sprung steel Figure 4 shows the clamp being put onto a surface.<'>'<' '>. Figure 5 shows the clamp released, clamping the surface under the force of the sliding element spring. Figure 6 shows the top o the clamp being pushed down, flattening the profi led spring steel sheet. Figure 7 shows the moving element being pulled down, releasing the clamp from the surface. Referring to the drawings the last clamping device comprises a sheet material I formed into a 'c' shape. This main body 1 o the clamp has a slot in the central section. Fastened between and running perpendicular the top and bottom surface of the main body is a shaft 3. Fastened to the underside of the top surface on the main body is a piece of sprung sheet. This steel is bent into a profile such that it can be flattened between the surface to be clamped to and the underside of the top surface when pressure is applied to the top of the clamp. The sliding element 5 of the clamp has a hole through it and slides up and down the shaft 3. When force is applied to the end of the sliding element 5 that is below the sprung steel 2 the tolerances between the hole and the shaft are such that the hole catches on the shaft and the element remains in position. As this force is reduced to zero the element slides up the shaft under the force of the spring 6. The right angled piece of material 4 is fastened to the sliding element 5 such that when force is applied to the end of the sliding element 5 the is outside of the 'c' shape main body 1 , it will slide up and down the shaft without catching. It is this end of the sliding element that is moved up and down in order to accommodate surfaces of varying thickness. Figure 4 shows the clamp being fully opened and introduced to the surface to be clamped. The right angled piece 4 ensures that the sliding element can be slid without catching on the shaft. Figure 5 shows the clamp around the surface . Figure 3 a&b shows the clamp before and after the sprung steel has been flattened. Prior to the sprung steel being flattened the clamping force is approximately equal to the force being applied by the spring 6. After the clamp has been pushed down the clamping force is approximately equal to the force applied when pushing down. Figure 6 shows the clamp being pushed down. As it is pushed down the sliding element maintains contact with the underside of the surface, and then when the pushing force is removed the sliding element retains it's new position and thus the clamping force remains. In order to release the clamp, the sl iding element is pushed down, which releases the clamp f rom the surface as shown m figure /

Claims

CLAIMS _-,

1. A means of clamping that can be secured to items of various thickness whereby the clamping force can be increased by applying pressure to a sprung part and this clamping force is maintained on release of the pressure.

2. A means of clamping as claimed in claim 1 whereby upon compression o the sprung part that is in contact with one side of the clamped item a sliding element moves and maintains contact with the other side of clamped item.

3. A means of clamping as claimed in claim 2 whereby the clamp can be used on items of various thicknesses due to a sliding element that has a hole through it and slides on a shaft

4. A means of clamping as claimed in claim 3 whereby the clamping force on the sliding element is offset from the hole causing the hole in the element to grip on the shaft.

5. A means of clamping as claimed in claim 4 whereby the sliding element only catches when a force is applied to the end that is in contact with the item being clamped.

6. A means of clamping as claimed in claim 5 whereby a piece of material attached to the sliding element and running in parallel and against the shaft stops the it from catching when a load is applied to the end no in contact with the clamped item thus allowing the user to slide the element up and down the shaft.

7. A means of clamping as claimed in claim 4 whereby upon lessening of the offset load the sliding element moves along the shaft under the action of the spring and when the offset load increases the element maintains it's new position.

8. A means of clamping as claimed in claim 2 and 7 whereby the compression of the sprung part allows the sliding element to move to and maintain a new position.

9. A means of clamping as claimed in claim 2 whereby the sprung part comprises a sprung steel leaf spring.

10. A means of clamping as claimed in claim 4 wherein the shaft is circular.

1 1. A means of clamping as claimed in claim 9 whereby the sliding element is kept from rotating around the shaft by having some of the element passing through a slot running behind and parallel to the shaft 12 A means of clamping as claimed in claim 1 whereby Ihe clamping can be achieved with the use of one hand.