GB2460700A

GB2460700A - Clamping apparatus for clamping an object during sawing

Info

Publication number: GB2460700A
Application number: GB0810436A
Authority: GB
Inventors: Wayne Robert Rathbone
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-06-07
Filing date: 2008-06-07
Publication date: 2009-12-09
Also published as: GB0810436D0

Abstract

An apparatus 101 for clamping to an elongate object during sawing of the object, comprises a first clamping means 102 having a first pair of opposing open ended jaws (404A, 406A, fig 4), a second clamping means 103 having a second pair of opposing open ended jaws (404B, 406B, fig 4), and a connecting member 112 rigidly connecting the first clamping means to the second clamping means. The first clamping means is configured to clamp onto a horizontally arranged elongate article, such as a piece of wood 302, with a sufficiently strong force to support the weight of the apparatus. Preferably, spring means urge the first and second pair of clamping jaws towards the closed position. A second connecting member 111 may also be provided.

Description

Clamping Apparatus This application represents the first application for a patent directed toward the invention and the subject matter.

BACKGROUND OF THE INVENTION

The present invention relates to an apparatus for clamping to an elongate object during sawing of said object, and to a method for cutting an elongate object into two pieces.

It is common practice, when sawing a length of timber into two pieces, to rest a portion of the timber on a support such as a bench such that a second portion, that is to be cut, overhangs the support. The timber is then cut. A problem with such practice occurs when the timber is almost sawn through.

The weight of the piece that is unsupported by the bench, if not now supported during the final stages of sawing, will generally drop under its own weight and consequently splinters will be pulled from it and/or the supported piece. A known solution is for the person sawing to support the otherwise-unsupported piece with one hand while sawing with the other hand. However, for reasons of health and safety this solution is not ideal, and in some situations it may be completely impractical.

A similar problem also occurs when cutting plasterboard. In this case, if the board is not properly supported its covering may tear and the plasterboard itself may become damaged.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided an apparatus for clamping to an elongate object during sawing of said object, said apparatus comprising: a first clamping means comprising a first pair of opposing open ended jaws; a second clamping means comprising a second pair of opposing open ended jaws; and a first connecting member rigidly connecting said first clamping means to said second clamping means, wherein said first clamping means is configured to clamp onto a horizontally arranged elongate article with a sufficiently strong force to support the weight of the apparatus.

According to a second aspect of the present invention, there is provided a method for cutting an elongate object into two pieces, said method comprising: clamping a device to an elongate object at a first position and a second position spaced apart from said first position; cutting through said object along a line between said first and second positions to create a first piece of said object and a second piece of said object; and releasing said first and second pieces from said device, wherein said device is clamped to said first piece by a sufficiently strong force to support the weight of said device and said second piece.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Figure 1 shows a perspective view of a clamping device 101 embodying the present invention; Figure 2 shows a top view of the clamping device 101; Figure 3 shows the clamping device 101 in use; Figure 4 shows a perspective view of an alternative clamping device 401 embodying the present invention; and Figure 5 shows a side view of the clamping device 401.

DESCRIPTION OF THE BEST MODE FORCARRYING OUT THE

INVENTION

Figures 1 and 2 A clamping device 101 embodying the present invention is shown in the perspective view of Figure 1 and the top view of Figure 2. The clamping device 101 is formed from a pair of spring clamps 102 and 103 of a type that is known for clamping together items such as lengths of timber during, for example, bonding. Such spring clamps are currently produced by a number of manufacturers and sold under various trade names including Babco and Draper�.

The spring clamps 102 and 103 are essentially identical and therefore each is formed of a first jaw 104 and an integrally formed first handle 105, and a second jaw 106 and an integrally formed second handle 107. The first and second jaws 104 and 106 are connected by a hinge mechanism including a pivot pin 108. A spring (not shown) is located about the pivot pin 108 and arranged to urge the handles 105 and 107 apart and the jaws 104 and 106 together.

A respective clamping element 109 is pivotally attached to each jaw 104, 106 at its free end. The clamping elements 109 have substantially planar opposing surfaces such that they are able to stably clamp onto objects having flat surfaces, such as sawn timber, plaster board, etc. Portions 110 of the jaws between the hinge mechanism and the clamping elements are provided with teeth, and consequently the spring clamps may be used to clamp around objects having non-flat surfaces, such as pipes.

The clamping device 101 also comprises a pair of connecting members 111 and 112. In the present embodiment the connecting members are identical inform, each connecting member being iormed of a length of metal tubing having a diameter chosen to be a good fit over the handles of the spring clamps 102 and 103. The connecting members 111, 112 are each provided with a pair of 90° bends 113, so that end portions 114 of a connecting member are substantially parallel to each other. The connecting members are therefore a C-shape. In the present embodiment the C-shape essentially follows three sides of a rectangle, but it should be understood that other C-shapes, such as a semicircle, may be used.

A first handle 105 of each spring clamp 102, 103 is fitted in a respective end of the first connecting member 111, and the second handles 107 of the spring clamps are fitted into respective ends of the second connecting member 112. Thus, as shown in Figure 2, the axes Al and A2 of the hinge mechanisms of the clamps 102 and 103 are collinear. Furthermore the axes A3 about which the clamping elements 109 may swivel are parallel to the axes A1,A2 of the hinge mechanisms.

In the present embodiment a screw 115 is located through each of the end portions 114 of the connecting members 111, 112 and through the handles 105, 107 to ensure the handles are securely retained within the connecting members. However, in other embodiments other fixing means are used, such as other types of mechanical fasteners, adhesives, etc. In the present example 50mm spring clamps have been used, but in other embodiments 25mm and 75mm spring clamps are used.

In the present embodiment two connecting members have been used.

In an alternative embodiment a single connecting member is used to rigidly connect the first handles 105 of each of the spring clamps 102, 103, and the second handles 107 are left free. However, this alternative embodiment has been found to be structurally less stable than the embodiment of Figures 1 and 2. -Figure 3 The clamping device 101 of Figures 1 and 2 is shown in use in Figure 3.

In the present example, a person 301 is using the device to assist with sawing a length of timber 302 into two pieces.

To use the device 101, the two pairs of jaws are opened by pressing together the two connecting members 111, 112 against the force of the springs of the spring clamps. The two pairs of open jaws are then arranged either side of a line 303 along which the object 302 is to be cut. Pressure on the connecting members 111, 112 is then reduced to allow the springs to clamp the jaws onto the object.

A portion 304 of the object to be cut 302 is then located on a suitable support, such as, in this example, a bench 305. A second portion 306 of the object 302, to which the device 101 is clamped, extends away from the support 305 while the object is cut along the desired line 303. As shown in Figure 3, the device is typically located to one side of the object 302 to be cut, while the user stand to the other side of the object. When a saw is being used to cut the object, it may be located between the end portions 114 of the connecting member 111, 112 to initiate the sawing process.

While the object 302 is being cut into two pieces 307, 308, the clamping device 101 supports the piece 307 that is not supported by the support 305.

Consequently, the user 301 is able to saw completely through the object 302 without the piece 307 dropping and causing damage to itself or the other piece 308, such as by splintering.

To provide support in this way it is essential that the device 101 is able to support the weight of itself by the gripping force it exerts on the supported piece 308 of the object 302. Furthermore, it must also support the weight of the piece 307 that is not supported by the bench 305. Specifically, when the object is cut through, the weight of the device and the otherwise-unsupported piece 307 generates a moment of force about the clamp 103 fixed to the supported piece 308. The clamp 103 is therefore required to provide a sufficiently strong grip on the object to prevent displacement that would otherwise be caused by that moment of force.

In addition, it will be understood that the second clamp must also provide a sufficiently strong grip to hold the piece 307 firmly.

It may be noted that in the present embodiment the clamping device is essentially symmetrical. Consequently, either pair of jaws may be used to clamp onto the piece 307 supported by the bench or the otherwise-unsupported piece 308.

Figures 4 and 5 An alternative clamping device 401 embodying the present invention is shown in the perspective view of Figure 4 and the side view of Figure 5.

The device 401, like device 101, has two pairs of jaws 402 and 403.

The first pair of jaws 402 comprises of a first jaw 404A connected to a second jaw 406A by a hinge mechanism including a pivot pin 408A. Similarly, the second pair of jaws 403 comprises a first jaw 404B connected to a second jaw 406B by a hinge mechanism including a pivot pin 408B. The jaws of device 401 are of a similar form to those of the device 101. Each pair of jaws is provided with a spring 420 (shown in Figure 5) which acts to urge the jaws into the closed position. In the present case the springs 420 are helical springs having straight end portions 421. The helical portions of the springs 420 being located about the respective pivot pin 408A, 408B.

The device 401 essentialIydiffersfrom devicei01 in that the jaws 404A and 404B are integrally formed with a connecting member 411, and similarly the jaws 406A and 406B are integrally formed with a connecting member 412.

In each instance, the jaws and connecting member are formed as a single moulding in a plastics material. To keep the device relatively light in weight, the connecting members 411, 412 are formed as U-shaped channels provided with webs 422 connecting the sides of the channel.

The operation of the clamping device is essentially the same as that of device 101 and therefore the jaws are openable by forcing the connecting devices 411 and 412 towards each other.

The jaws 404A, 404B, 406A and 406B are provided with clamping elements 409 rotatably mounted at the ends of the jaws. In the present embodiment, the clamping elements are of a similar size and shape to corresponding elements on known spring clamps. However, in an alternative embodiment, the clamping elements are made wider and longer than those of known spring clamps, so that the clamping device is more suitable for supporting panels, such as plasterboards, during cutting.

Claims

Claims 1. An apparatus for clamping to an elongate object during sawing of said object, said apparatus comprising: a first clamping means comprising a first pair of opposing open ended jaws; a second clamping means comprising a second pair of opposing open ended jaws; and a first connecting member rigidly connecting said first clamping means to said second clamping means, wherein said first clamping means is configured to clamp onto a horizontally arranged elongate article with a sufficiently strong force to support the weight of the apparatus.
2. An apparatus according to claim 1 wherein said apparatus comprises a first spring means arranged to urge the first pair of jaws into a closed position.
3. An apparatus according to claim 1 or claim 2 wherein said first clamping means comprises a first hinge mechanism connecting the first pair of jaws.
4. An apparatus according to claim 2 or claim 3 wherein said apparatus comprises a second spring means arranged to urge the second pair of jaws into a closed position.
5. An apparatus according to any of claims 2 to 4 wherein said second clamping means comprises a second hinge mechanism connecting the second pair of jaws.
6. An apparatus according to any one of claim I to 5, wherein said apparatus comprises: a first hinge mechanism defining a first axis about which the first pair of jaws mutually rotate; and a second hinge mechanism defining a second axis about which the second pair of jaws mutually rotate, and said second axis is substantially collinear with said first axis.
7. An apparatus according to any one of claims 1 to 6, wherein a first jaw of said first pair of jaws is rigidly connected to a first end of said connecting member, and a first jaw of said second pair of jaws is rigidly connected to the opposite end of said connecting member.
8. An apparatus according to claim 7, further comprising a second connecting member, said connecting member having a first end rigidly connected to the second jaw of said first pair of jaws, and a second end rigidly connected to the second jaw of said second pair of jaws, such that said first and second pairs of jaws are openable by forcing said first connecting member towards said second connecting member.
9. An apparatus according to any one of claims 1 to 8, wherein said first connecting member and a first one of said first pair of jaws and a first one of said second pair of jaws are formed as an integral unit.
10. An apparatus according to claim 9, wherein said integral unit is moulded from a plastics material.
11. An apparatus according to claim 9 or claim 10, wherein said second connecting member and the second one of said first pair of jaws and the second one of said second pair of jaws are formed as an integral unit.
12. An apparatus according to any one of claim 1 to 11, further comprising a respective clamping element pivotally attached to each of said jaws such that in use said clamping elements are arranged to clamp onto an elongate object.
13. An apparatus according to any one of claim 1 to 12, wherein said first pair of jaws extends substantially parallel to said second pair of jaws.
14. An apparatus according to any one of claim 1 to 13, wherein said connecting member is substantially C-shaped, so that when a straight object is located in said first and second clamping means, at least a middle portion of said connecting member is spaced apart from said object.
15. A method for cutting an elongate object into two pieces, said method comprising: clamping a device to an elongate object at a first position and a second position spaced apart from said first position; cutting through said object along a line between said first and second positions to create a first piece of said object and a second piece of said object; and releasing said first and second pieces from said device, wherein said device is clamped to said first piece by a sufficiently strong force to support the weight of said device and said second piece.
16. A method according to claim 15, wherein said method comprises opening jaws of said clamping device by pushing against a spring and then allowing the spring to clamp said jaws onto the elongate object.
17. A method according to claim 16, wherein said method comprises opening said jaws by rotating a first jaw with respect to a co-operating second jaw.
18. A method according to any of claim 15 to 17, wherein said device comprises two pairs of jaws, a first connecting member connecting a first jaw of each of said pairs of jaws, and a second connecting member connecting the second jaw of each of said pairs of jaws, and said method comprises bringing the first and second connecting members together to simultaneously open both pairs of jaws.
19. An apparatus for clamping to an elongate object during sawing of said object substantially as herein described with reference to the accompanying Figures.
20. A method of for cutting an elongate object into two pieces substantially as herein described with reference to the accompanying Figures.