GB2287208A

GB2287208A - Workpiece clamp and/or cutting guide

Info

Publication number: GB2287208A
Application number: GB9504993A
Authority: GB
Inventors: Nigel James Eastwood
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-03-12
Filing date: 1995-03-13
Publication date: 1995-09-13
Also published as: GB9404855D0; GB9504993D0

Abstract

Apparatus for use in sawing sheet material comprises a workpiece support surface (conveniently rectangular and made in two halves hingedly connected together), and a selected one or more of:- a) abutment means 9 for the workpiece and securable with respect to the workpiece support surface, b) one or more workpiece clamp bars 20 to be positioned spaced extending over the workpiece support surface to receive the workpiece therebetween and which is/are securable to the workpiece support surface, and c) a cutting guide 15 disposed spaced above and extending over the workpiece support surface to extend over any workpiece therebetween. Preferably both the abutment means and the culling guide are pivotably mounted and respective means is provided for securing them at a desired position. The clamp bars are preferably releasably securable to the workpiece support surface. <IMAGE>

Description

TITLE: Workpiece clamp and/or cutting guide DESCRIPTION The present invention relates to a device for clamping workpieces and/or provision of a cutting guide for same.

Work benches which clamp material for cutting are known, the Black & Decker Workmate (Registered Trade Mark) being a typical example. However, the capacity of the jaws is limited thereby restricting their ability to handle wider pieces of material and especially sheet materials. There is a requirement to be able to handle sheet materials of the order of 300mm wide and typically up to 600mm wide. As well as the ability to clamp such sheet material it is also advantageous to provide a guide which can be used in performing operations on the material, for example cutting using a circular saw, jigsaw or performing routing operations.

It is an aim of the present invention to provide apparatus which achieves one or more of the above aims.

Accordingly, the present invention provides apparatus comprising a workpiece support surface and a selected one or more of the following elements, the elements comprising: 1. abutment means for the workpiece and securable with respect to the workpiece support surface, 2. one or more workpiece clamp bars to be positioned spaced extending over the workpiece support surface to receive the workpiece therebetween and which is/are securable to the workpiece support surface, and 3. a cutting guide disposed spaced above and extending over the workpiece support surface and securable with respect thereto.

Advantageously the workpiece clamp bars are preferably releasable and advantageously can be secured in selected alternative positions relative to the workpiece support surface. More particularly the workpiece clamp bars comprise elongate members, conveniently a hollow rectangular box section member (eg. of steel, alloy or possibly plastics) and conveniently secured using say two securing elements.

Conveniently the securing elements comprise a male threaded member to engage threadingly with complimentary female threading. Conveniently the latter is mounted in the workpiece support surface. More particulary the securing elements are carried captively by the elongate members and disposed adjacent opposite ends thereof.

Preferably two workpiece clamp elements are provided.

The workpiece support surface has a plurality of threaded elements embedded or otherwise secured therein and conveniently at spaced intervals along at least two opposite edges of the support surface. The clamp bars may be secured to lie across the width of the support surface, or disposed lengthwise.

In an alternative embodiment, the securing element for the clamp bars comprise a lever or cam action. These may operate in conjunction with the afore-described threaded connection with the workpiece support surface. Alternatively the lever/cam arrangement may be arranged to clamp around the edge of the workpiece support surface.

Advantageously the workpiece support surface itself is formed in two parts conveniently two halves, and conveniently hingedly connected together so as to fold up when not in use. A carrying handle may be provided along one edge and means for holding the parts in the folded condition may be provided, say along an opposite edge.

The abutment means is preferably securable in different positions to position the workpiece at a desired angle on the workpiece support surface.

Conveniently the workpiece support surface is marked out with frequently used angles and more particularly still is provided with threaded elements which can be used to set the abutment means at prescribed angles, say 750, 600 and 450 relative to at least one and preferably both opposite parallel edges of the surface. Conveniently the abutment means is mounted to pivot from adjacent one end thereof and is provided with say a thread engaging securing member to its other end. Alternatively, there may be one or more arcuate slots cut in the workpiece support surface and receiving part of securing means for the abutment means whereby the abutment means can be secured at the desired position within the slot thereby provides continuously variable adjustment over the range of the arcuate slot.

The cutting guide is preferably pivotably adjustable to set at a desired angle with respect to the workpiece support surface. Conveniently the cutting guide is secured from beneath the workpiece support surface so that the upper surface is substantially uninterrupted to avoid hindering passage along the guide of any machine tool. A shallow projection is permissible. Advantageously the guide is of a length which extends beyond the width of the table at least to one end. Location means is conveniently provided which connects with the cutting guide to facilitate locating it at a prescribed angle. Conveniently said means cooperates with one of the clamp bars and/or with threaded engagers in the support surface.Conveniently said means comprises an elongate member drilled along its length at prescribed intervals and connectable by way of said holes with one of the clamp bars and at its other end with the cutting guide or at least an extension thereof. It will be apparent that the cutting guide extends over any workpiece which is positioned on the workpiece support surface.

The apparatus is intended to be used in conjunction with a work bench to support it above ground level and preferably includes an abutment by which it may be held clamped in the jaws of a work bench.

Alteratively it may be provided with support legs.

The present invention will now be described further, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view from one end and above of the apparatus according to the invention, Figure 2 is a perspective view of the apparatus of Figure 1 from above, one end and one side with abutment means angled, Figure 3 is a perspective view from above and one side of the apparatus of Figure 1 illustrating the cutting guide at an angle, Figure 3a is a perspective view showing in greater detail part of Figure 3, Figure 4 is a plan view of the apparatus of Figure 1, Figure 5 is a view on A of Figure 4, Figure 6 is a view on B of Figure 4 also illustrating support apparatus.

Figure 7 is a view on B of Figure 4 with the apparatus folded, Figure 8 is a fragmentary view on A showing how the guide can be used for cutting, and Figure 9 illustrates in section further detail of the securing element for a clamp bar.

Referring to the drawings, the apparatus according to the invention comprises a workpiece support surface 1 (shown in solid outline) comprising two halves 1A, 1B which are hingedly connected together as at 3.

Support for the apparatus, typically a work bench with adjustable clamp jaws is shown in Figures 1 and 2 at 5 in chain dotted outline. Longitudinal edging strips are provided on opposite parallel edges of the two halves as at 4A, 4B and a central board 7 is secured to each half, the function of which we will described further hereinafter. Figure 4 shows the surface in its opened out condition whilst Figure 7 shows the folded view side on.

The apparatus further comprises an adjustable workpiece guide 9 (abutment means) comprising an elongate bar, typically a strip of metal having holes 9a drilled in it at spaced intervals and which is securable to the workpiece support surface. Figures 1 and 4 show its typical position mounted parallel to one edge of the work surface. Mounting is conveniently by a first securing means 11 at one end comprising a threaded member actuable by a thumb screw 12 passing through a bore in the abutment means and threadingly engaged with threading in the support surface (see Figures 3 and 3a in particular). The other end carries a threaded securing member lla with enlarged grip portion and passing through a hole in the end of the guide member and received in threading in the support surface.The guide member can be pivoted about the first mentioned connection and the work table has threaded elements embedded therein (as at llb) to facilitate securing of the guide element at prescribed angles. In the illustrated embodiment these are at 750, 600 and 450 relative to the cutting edge 14 of the table. As an alternative or in addition one or more arcuate slots may be provided to facilitate securing at other angles. The arcuate slots may be on a different pitch circle diameter to the aforesaid threaded elements and to one another if so desired. The securing member lla may be provided with a threaded element arranged to run in the slot on the underside of the workpiece support surface.

The abutment means may be secured at either side of the table - see threaded hole llc to receive first securing means 11 and threaded hole lld to receive second securing means lla (Figure 4). Each edge of the table also has a plurality of spaced threaded holes 13a (complimentary in spacing to the holes 9a) the function of which is described further hereinafter.

Also illustrated is a height adjustable cutting guide rail 15 comprising an elongate bar of strip material and securable at one end to the cutting table by way of a securing element 17 shown in further detail in Figure 3a. The securing means is actuable from underneath the table and comprises a male threaded shank 18 and gripping handle 19. The threaded shank engages with a female threaded element 20 embedded in the support surface 1 concentric with bore 21. The end of the shank remote from the handle has a cross bore to receive a spring clip 22 retaining a washer 23. Said end passes through a bore in the guide bar 15 and the clip retains the securing element. A spring 24 disposed between table 1 and the underside of the guide 15 biases the latter upwardly when the securing element is released. A second such clamp is provided towards the opposite edge of the work surface as at 17a.The guide rail itself has a length greater than the width of the cutting table and also carries a mounting bracket 13 for corresponding engagement with means 19 (comprising an elongate bar) for clamping the cutting rail at a desired angle with respect to the workpiece support surface.

The apparatus further comprises two workpiece clamps 20 which comprise elongate members which are of hollow rectangular section steel in the illustrated embodiment, although other materials and sections could be employed. The opposite ends of the clamp bars are provided with securing elements 21 comprising threaded members 21a carried captively by the clamp bars (for example, by nuts 21b located non-rotatably with respect to the clamp bars) (for example held captive inside the hollow sections) and engageable with corresponding female threaded members embedded into the workpiece support surface as designated by fixing holes 13a which are spaced along two opposite sides of the support surface.In addition the clamp bars contain through holes 27 approximately intermediate their length to receive securing elements to engage with one of a series of corresponding spaced threaded formations 13b in the workpiece support surface. These are used in the case where material less than one half the full width of the clamp bars is being employed to achieve a better clamping function. The holes 27 can also be used to mount the angular adjusting means 19 for the cutting guide. This comprises a strip of material with bores 19a at preset distances illustrated further in Figure 3.

The underneath of the workpiece clamp bars carries a resilient element strip (not illustrated) such as rubber or foam, so as to avoid marking the workpiece and a similar material is provided along the underside of the cutting guide. An adjustable template 40 (shown in Figures 2 and 4) comprising two relatively movable elements 40a, 40b and clamp means (not illustrated) can be set to the distance x between the edge of the power tool P which will be positioned up to the cutting guide 15 and the position of its blade B so as to position the workpiece cutting line correctly in relation to the cutting guide.

Referring to Figure 4 two alternative positions for a workpiece are shown, the first W1 with it mounted parallel to the left edge and the second W2 at an angle of 600 to said edge. In the latter case (see Figure 2) the adjustable workpiece guide 9 is moved out to the 600 fixing point llb. The securing means 21 for the clamp bars 20 engage directly into threaded holes 13a in the workpiece.

In the illustrated embodiment when the guide bar is parallel to said edge as in Figures 1 and 3, the securing means 21 are arranged to pass through clearance bores 9a in the abutment means 9 before entering the threaded holes 13a. This arrangement enables the width of the work support surface to be kept to a minimum.

When this is not paramount the abutment means is inset from the edge of the workpiece support surface so that the line of threaded inserts 13a is between the edge of the workpiece support surface and the line of the abutment means when set parallel to that edge. This avoids the need for the securing elements 21 for the clamp bars to pass through holes in the abutment means in the parallel position.

Operation of the device will be described further hereinafter with reference in particular to Figures 1, 2 and 3 which are examples of three different configurations. Referring firstly to Figure 1, for use the two halves of the table are hinged apart to form a planar work support surface. The centre beam 7 may be clamped in the jaws J1, J2 of a work bench (see Figure 6). The abutment means 9 is shown secured along one side edge of the table using securing means 11 (not illustrated in Figure 1) and screw means 11a towards the opposite end thereof. The cutting guide 15 is shown extending at right angles to the abutment means 9 and parallel to the end edge 14 of the support surface. It will be seen that the cutting guide 15 is inset from the end 14. This is because the cutting guide is intended for use with power tools in which their cutting tool will be set at a distance from a guide plate and it will be the guide plate which abuts against the cutting bar in use thus when positioning a workpiece it will be the distance between the cutting tool of the power tool to be used and its guide face which will be used in setting the position of the workpiece in respect to the cutting guide. Two clamp bars 20 as shown extending transversely across the support surface with respective securing means 21 to each end. At the left hand edge the securing means pass through holes 9a in the abutment member 9 in the illustrated embodiment, whereafter they are received in threaded holes 13a in the table.However, it will be appreciated that in another embodiment the abutment means 9 may be set inwardly of the line of holes 13a so that movement of the abutment member can be independent of the positioning of the clamp bars 20 and the securing means cooperate with holes 13a directly, ie. without having to pass through the holes 9a which may be dispersed with in such an embodiment. At the other edge of the table the clamp bars are secured by securing means 21 engaging with appropriate holes 13a in the table. With the securing means 21 released a workpiece can be slid underneath the raised clamp bars and positioned with one edge up to the abutment means 9 and slid along until the cutting line is correctly positioned relative to the cutting guide where this is to be used.The cutting guide 9 will be clamped in place by tightening the securing means 17, 17a to draw the cutting bar 15 down into contact with the workpiece against spring biasing (see Figure 3a for detailed construction). The securing means 21 are then done up to clamp the workpiece in place.

Referring now to Figure 2 here we show how the abutment means 9 has been displaced to lie at an angle of 600 with respect to end edge 14. The securing means lla is engaged in the appropriate threaded hole 11b to define the 600 angle and then firmly secured in place by doing up the fixings 11 and lla. In the illustration the cutting guide remains parallel with the edge 14 and the workpiece is positioned to the appropriate distance from the cutting guide to allow for the machine tool to be positioned on the correct point before clamping down the cutting guide 15 and the clamp bars 20 using the securing means 17, 21 respectively. Thus, a power tool run along cutting guide 15 will cut the workpiece W at the required angle.

Referring now to Figure 3 here we illustrate how the cutting guide can be moved angularly with respect to the workpiece support surface. This is particularly useful when dealing with wider pieces of workpiece which could not be mounted in the manner illustrated in Figure 2. In this instance the abutment guide 9 remains disposed parallel to the edge of the work surface whilst the cutting guide 15 is swung about pivot location 17.

The positioning bar 19 is connected to the cutting guide by way of bracket 18 and fixing screw 18' and the bar 19 is connected to clamp bar 20 by way of a fixing screw 18" engaging in a hole 27 of the clamp bar 20. The positioning of holes 19a in the bar 19 serves to adjust the cutting guide by precise angles for example 150, 300, 450.

It will be apparent that with the combination of clamp bars, abutment means and cutting guides, sheet material can be clamped in order to perform machining operations. It is envisaged that apparatus will be provided in different sizes to accommodate different maximum widths of material, with perhaps one catering for material up to 600mm in width whilst others may be adapted for specialist operations for say doors providing a width of up to 1000mm, or otherwise to suit most useful envisaged applications.

Claims

1. Apparatus comprising a workpiece support surface and a selected one or more of the following elements, the elements comprising:a) abutment means for the workpiece and securable with respect to the workpiece support surface, b) one or more workpiece clamp bars to be positioned spaced extending over the workpiece support surface to receive the workpiece therebetween and which is/are securable to the workpiece support surface, and c) a cutting guide disposed spaced above and extending over the workpiece support surface and securable with respect thereto.

2. Apparatus as claimed in claim 1, in which the one or more workpiece clamp bars are releasable from the workpiece support surface.

3. Apparatus as claimed in claims 1 or 2, in which the one or more workpiece clamp bars are securable in selected alternative positions relative to the workpiece support surface.

4. Apparatus as claimed in any one of claims 1, 2 or 3, in which the one or more workpiece clamp bars comprise elongate members.

5. Apparatus as claimed in claim 4, in which the workpiece clamp bar comprises a hollow rectangular boxsection member.

6. Apparatus as claimed in any one of claims 1 to 5, in which the workpiece clamp bar is secured to the workpiece support by two securing elements.

7. Apparatus as claimed in claim 6, in which the securing element comprises a male threaded member to engage threadingly with complimentary female threading.

8. Apparatus as claimed in claim 7, in which the female threading is mounted in the workpiece support surface.

9. Apparatus as claimed in claims 6 or 7, in which the securing elements are carried captively by the workpiece clamp bar and disposed adjacent opposite ends thereof.

10. Apparatus as claimed in claim 8, in which the workpiece support surface has a plurality of threaded elements embedded or otherwise secure with respect thereto and disposed at spaced intervals along at least two opposite edges of the support surface.

11. Apparatus as claimed in claim 6 or claim 9 when appendant to claim 6, in which the securing elements comprise a lever/cam action device.

12. Apparatus as claimed in claim 11, in which the lever/cam action device engages around the edge of the work surface support.

13. Apparatus as claimed in any one of the preceding claim, in which the workpieces support surface is generally rectangular.

14. Apparatus as claimed in any one of the preceding claims, in which the workpiece support surface is formed in two parts hingedly connected together.

15. Apparatus as claimed in any of one of the preceding claims, in which the abutment means is securable in different positions to position a workpiece, in use, at a desired angle on the workpiece support surface.

16. Apparatus as claimed in claim 15, in which the abutment means is angularly adjustable.

17. Apparatus as claimed in claim 16, in which the abutment means is mounted to pivot adjacent one end thereof and is provided with a securing member to its other end.

18. Apparatus as claimed in claim 15, 16 or 17, in which the adjustment range of the abutment means is continuously variable.

19. Apparatus as claimed in claim 15, 16 or 17, in which the abutment means can be located at a restricted number of prescribed positions with respect to the workpiece support surface.

20. Apparatus as claimed in any one of the preceding claims, in which the cutting guide is pivotably adjustable to set at a desired angle with respect to the workpiece support surface.

21. Apparatus as claimed in any one of the preceding claims, in which the cutting guide is at least partially secured from beneath the workpiece support surface.

22. Apparatus as claimed in any one of the preceding claims, in which the cutting guide is of a length which extends beyond the width of the workpiece support surface.

23. Apparatus as claimed in any one of the preceding claims, further comprising location means connectable with the cutting guide to facilitate location of the cutting guide at a prescribed angle.

24. Apparatus as claimed in claim 23, in which the location means cooperates with one of the workpiece clamp bars or with threaded engagers of the workpiece support surface.

25. Apparatus as claimed in claims 23 or claim 24, in which the location means comprises an elongate member having spaced through bores along its length and connectable with one of the clamp bars and with the cutting guide.

26. Apparatus as claimed in claim 1 and comprising the one or more clamp bars according to any one of claims 2 to 14 and the abutment according to any one of claims 15 to 19.

27. Apparatus as claimed in claim 1 and comprising one or more clamp bars according to any one of claims 2 to 14 and the cutting guide according to any one of claims 20 to 25.

28. Apparatus as claimed in claim 1 and comprising the abutment means according to any one of claims 15 to 19 and the cutting guide according to any one of claims 20 to 25.

29. Apparatus as claimed in any one of the preceding claims further comprising an abutment to facilitate holding in the jaws of a vice or vice-like work bench.

30. Apparatus as claimed in any one of the preceding claims further comprising support legs.

31. Apparatus constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.