GB2148180A

GB2148180A - Tooling jig

Info

Publication number: GB2148180A
Application number: GB08327787A
Authority: GB
Inventors: Douglas Frederick Charles Ede; David Leo Elwes Parkin
Original assignee: Newjig Ltd
Current assignee: Newjig Ltd
Priority date: 1983-10-18
Filing date: 1983-10-18
Publication date: 1985-05-30
Also published as: GB8327787D0; GB2148180B

Abstract

A workbench in which a bridge formed by a T-shaped member 32, 34 is pivotally connected via brackets 20, 22 to the workbench top 12 in such a way that the bridge can be lifted up to introduce a workpiece 100 and then pivoted down again to rest on the workpiece. Slots 21, 23 in the brackets allows for the accommodation of workpieces of different size and the pivotal connection can then be secured by clamps 24, 26. The position of the workpiece and the position of the tool, for example, saw 58 can be defined in a modular fashion by a positioning apparatus which can include either the adjustable stop 110 or an adjustable soleplate 56 for the tool, wherein a spring-loaded element such as a ball 113 is engageable in one of several equispaced detents 50, 52 whereafter the position can be secured by clamp 116 engaged in an adjacent detent. <IMAGE>

Description

SPECIFICATION Workbench The present invention relates to a workbench and to apparatus for positioning a workpiece to be machined.

Various tooling jigs have been suggested for the do-it-yourself man or the professional woodworker.

For example, in British Patent No. 1,529,642 it has been proposed to provide a tooling jig comprising a base for supporting a workpiece, a longitudinally extending guide fence provided on the base, the guide fence defining a straight edge, a bridge which is directly secured to the guide fence and positioned to overlie a workpiece placed against the guide fence and a guideway on the bridge extending accurately perpendicular to and intersecting the line of the straight edge, the guideway being adapted to guide for movement therealong a router accurately perpendicular to the straight edge.

The construction illustrated in that Patent is very satisfactory but the particular embodiments disclosed therein have certain disadvantages both from a practical and from an economical constructional point of view.

It is now proposed, according to the present invention, to provide a workbench comprising a support having a working surface, a fence pivotally mounted on said support and normally extending above said working surface, whereby the rear edge of a workpiece placed on said working surface can be abutted against said fence, a bridge carried by said working surface to overlie said workpiece, a guideway on said bridge for guiding a machine tool, said guideway extending accurately perpendicular to said fence, a slot in said bridge for the passage of a cutter of said machine tool as it is so guided, the pivotal connection between the fence and the support allowing limited vertical movement of said fence and bridge, to accommodate different thicknesses of workpiece.

With such a construction, it is easy to position a workpiece on the working surface by first of all lifting the bridge by pivoting it about the pivotal connection, and then lowering the bridge onto the workpiece. The pivotal connectiion between the fence allows for limited vertical movement of the fence and the bridge, thus to accommodate workpieces of different thickness. The bridge will actually lie flat on the top of the workpiece and the pivotal connection is preferably clampable in the thus defined position.Preferably, therefore, the pivotal connection comprises a bracket on each side of the support having a generally upwardly extending slot therein, a slider in each slot and a pivot pin passing through, or formed on, said slider and a tightenable clamp for holding the slider in the position which it takes up when the fence and bridge have been pivoted downwardly onto a particular workpiece.

In an advantageous and economic construction the bridge is formed as the stem of a generally Tshaped sheet material member, the fence being secured directly to, or formed as part of, the crosspiece of the T.

One particular form of the guideway on the bridge is a pair of dogleg cross-section strips mounted in complementary facing relation and secured to the upper surface of said stem of the T and Having flanges facing one another and overlying a portion of the T to form the guideway for a soleplate for mounting the tool.

The soleplate may be of a generally square shape and have a slot or slots therein for the passage of the cutter of the tool. Advantageously, the flanges are provided with a plurality of equally spaced detents and said soleplate carries a member movable relative to said flanges, said member being provided with a spring-loaded element, selectively engageable in one of said detents, to locate the soleplate at a particular position on the guideway. Such an arrangement enables the soleplate to be positioned at a particular desired modular position so that the finished workpiece has a particular modular size.Having determined the particular position of the workpiece by clicking the spring-loaded element in a particular detent, one can then clamp the movable member by a clamp thereon which preferably comprises a threaded rod passing through a threaded bore in said member and which is laterally spaced from said springloaded element by a distance equal to the spacing between said detents, or a multiple thereof, so that the end of the threaded rod can be screwed into engagement with another of said detents.

In order to ensure firm clamping of the soleplate, preferably a second threaded portion is formed in a member associated with said soleplate, at a point thereof remote from said threaded bore, and a second threaded rod passes through said second threaded bore whereby the second threaded rod may be screwed into engagement with a further one of said detents.

If the bridge is used in the manner described in British Patent No. 1,529,642 to cut off and machine accurately the end of a workpiece, then these arrangements described immediately above are not used, but rather the soleplate is caused to slide freely along the guideway. However, during this movement the workpiece needs to be accurately positioned relative to the fence and advantageously the edge of the crosspiece of the T is provided with a plurality of equally spaced detents and a relatively movable stop which is adapted to position the workpiece is provided with a springloaded element selectively engageable in one of said detents, to locate the movable stop at a particular position on the crosspiece of the T.

The invention also provides, in this way, apparatus for relative positioning a workpiece to be machined, and a tool for cutting the workpiece, whereby the cut of the tool is produced at a desired modular position, said apparatus comprising an elongate guide having a plurality of equally spaced detents and a relatively movable member adapted to position the workpiece, or the tool, the movable member having a spring-loaded element selectively engageable in one of said detents, to lo cate the movable member at a particular position on the elongate guide and means to guide the tool or workpiece whereby it can be moved perpendicular to the length of the elongate guide to effect the cut.

In order that the present invention may more readily be understood, the following description is given, merely by way of example, reference being made to the accompanying drawings, in which: Figure 1 is a perspective view of one embodiment of workbench according to the invention; Figure 2 is an enlarged perspective view of the workpiece stop of the workbench of Figure 1; Figure 3 is a cross-section through the stop of Figure 2; Figure 4 is a plan view of the stop of Figures 2 and 3; Figure 5 is a plan view, partly in section, of a modified version of the stop of Figure 4; Figure 6 is a plan view of a soleplate of the work bench of Figure 1; and Figure 7 is a side elevation of the soleplate of Figure 6.

Referring first to Figure 1 of the drawings, there is illustrated a workbench comprising four legs 10 which may be provided with adjustable feet (not shown), the four legs being connected to an inner frame which cannot be seen in Figure 1. Around this inner frame is mounted a bench top 12 formed of a reinforced plastics material and having an upper working surface 14. Let into this upper working surface are two channel section guideways 16, 18 which extend from front to back of the working surface 14. Extending from the front to rear between the guides 16, 18 there is a channel 19 having a depth of approximately 10 centimetres for a reason to be explained later.

Upstanding from the frame (not shown) within the top 12 are two brackets 20, 22 provided with vertically extending slots 21, 23. A slider is slidable in each of these slots. It can be seen that there are two knurled knobs which cooperate with a threaded pivot pin, only one of which can be seen at 27. This pin is passed through a flange 28 while the other pin is passed through a flange 30, the two flanges forming upturned parts of the crosspiece 32 of a generally T-shaped sheet metal member the stem of which is shown at 34 and forms a bridge extending over the working surface 14.

Extending along the length of the bridge 34 is a closed ended slot 36 and extending below the surface of the cross-piece 32 of the T-shaped plate is a downwardly extending fence 38, which is illustrated in phantom.

Welded to the upper surface of the stem 34 of the T shaped plate are two parallel dogleg crosssection strips 40 and 42 having a generally horizontal lower leg 44, an upstanding part 46 and an inwardly facing flange 48. The strips 40, 42 are arranged parallel to one another and accurately perpendicular to the fence 38. It will be seen that each strip is provided with a plurality of equi-distantly spaced apertures 50 forming detents. Similarly the portion of the crosspiece 32 forwardly of the fence 38 is provided with a plurality of equidistantly spaced apertures 52 again forming detents.

The front edge of the bridge 34 is upturned at 54 and the lower legs 44 extend forwardly from the upstanding portions 46 and the flanges 48, so that the forward edges of the flanges 48 are spaced from the flange 54 by an amount approximately equal to the spacing between the upstanding portions 46. This means that a square soleplate 56, which is shown in Figure 1 as carrying a saw 58, can be placed on the forward part of the bridge and can then be slid rearwardly so that its edges pass under the flanges 48.

The soleplate is illustrated more clearly in Figure 6 and Figure 7 and is, as indicated above, of generally square shape in plan. The lefthand edge as viewed in Figure 1, that is the lower edge as viewed in Figure 6, is provided with a first member 60 secured by bolts 62 and with a second member 64 secured by bolts 66. Each member is provided with an overhanging portion 68, 70 defining therebelow, with the upper surface of the plate 56, a slot 72, 74. The body of the member 60 has a spring-loaded element 76, the spring of which urges the element (usually a ball) downwardly towards the upper surface of the plate 56. in use, when the plate is mounted as shown, the flange 48 extends into these slots.It will be appreciated that one can slide the plate 56 along the length of the guideway formed by the strips 40, 42 and that the sprung-loaded ball 76 will engage in turn in ne of the detent holes 50. This defines a particular position of the soleplate and allows for modular location of the saw 58. Having defined the desired modular position, one can firmly clamp the soleplate at that modular position by screwing down bolts 80 and 82 mounted on the first and second members 60 and 64 respectively. The position of the bolts 80 and 82 is such as to allow the lower end to engage in another detent hole 50. Because the members 60 and 64 are spaced, a firm clamping is achieved.

It will be seen that the plate 56 is provided along the rear edge, with a plurality of apertures 84 and it is contemplated that these can have inserted therein a tub shaped drill holder which accommodates the chuck of a drill and allows the drill bit to pass downwardly therethrough and through the respective hole 84. In this way one can drill holes in the face of a workpiece again at a particular modular position.

It will be noted that, if one desires to work off module, that is at a position other than that defined by the spring-loaded ball 76 entering a detent 50, one can still clamp the soleplate as described before, that is with a detent engaged by the springloaded ball, and one can move the soleplate a limited amount by loosening off the screws 62 and sliding the plate relative thereto a limited amount accommodated by slots 86.

The soleplate 56 is also provided with an elongate slot 88 for the passage of the sawblade and with a number of other apertures to assist in various routing operations, for example in order to produce the necessarily shaped aperture for mounting a hinge on a panel.

The workbench so far described is used first of all by lifting the T-shaped plate so that it pivots about the threaded pivot pin 27 and a workpiece which is indicated at 100, is introduced onto the top of the working surface 14. The T-piece is then lowered by hinging about the pivot pins 27 until it lies on top of the workpiece. Depending on the thickness of the workpiece the slider associated with each pivot 27 will position itself at the appropriate location in the slot 21, 23. The clamps 24, 26 can then be tightened up and the T-shaped plate will then be positioned correctly for that workpiece.

The workpiece is then slid out somewhat and the saw 58, mounted on the plate 56, is positioned on the guideway formed by the strips 40, 42 as indicated above. The actual location is selected for the particular longitudinal saw cut one wishes to make and the soleplate is clamped in the appropriate position. Thereafter, a pusher strip 102 is introduced under the bridge formed by the T piece and the guides 16, 18 are used to accommodate T-bolts having clamping nuts 103, 104. The pusher 102 is located against the leading edge of the workpiece which can then be slid relative to the saw so that a saw cut 104 is formed accurately at the correct plate, the fence 38 and the pusher 102 guiding the workpiece 100 accurately during this movement.

If it is desired to carry out other working operations, for example, making a transverse cut, then the clamps 80, 82 are undone and the soleplate removed and turned through a right-angle, so that the saw blade extends into the slot 36. The workpiece is then positioned to give the right length of workpiece in a manner to be described below. For this purpose, the workbench is provided with a stop 110 which is illustrated in detail in Figures 2, 3 and 4. The body of the stop 110 is provided with a rear re-entrant slot 112 which can be engaged over the front edge of the crosspiece 32. As described above, with reference to the member 60, the stop 110 is also provided with a spring loaded element, e.g. a ball which is indicated by the reference numeral 113 and is urged downwardly by spring 114.

The ball is arranged to engage in the detent apertures 52 described previously and a clamp 116 can be engaged in an adjacent detent in a similar manner to that described earlier. This again gives a modular positioning of the stop, to give a modular length of workpiece when one moves the saw along the guideway formed by the strips 40, 42.

Occasionally one wishes to make a cut which is off module and for this purpose the stop can be modified as shown in Figure 5 by the provision of an adjustable or movable part 118 the position of which, relative to the stop 110, can be changed by slackening of clamps 120, 121 and sliding the part 118 relative thereto, this movement being accommodated by the slots 122, 123.

Claims

1. A workbench comprising a support having a working surface, a fence pivotally mounted on said support and normally extending above said working surface, whereby the rear edge of a workpiece placed on said working surface can be abutted against said fence, a bridge carried by said working surface to overlie said workpiece, a guideway on said bridge fór guiding a machine tool, said guideway extending accurately perpendicular to said fence, a slot in said bridge for the passage of a cutter of said machine tool as it is so guided, the pivotal connection between the fence and the support allowing limited vertical movement of said fence and bridge, to accommodate different thicknesses of workpiece.

2. A workbench according to claim 1, wherein the pivotal connection comprises a bracket on each side of the support having a generally upwardly extending slot therein, a slider in each slot and a pivot pin passing through, or formed on said slider and a tightenable clamp for holding the slider in the position which it takes up when the fence and bridge have been pivoted downwardly onto a particular workpiece.

3. A workbench according to claim I or 2, wherein the bridge is formed as the stem of a generally T-shaped sheet material member, the fence being secured directly to, or formed as part of, the crosspiece of the T.

4. A workbench according to claim 3, wherein the guideway on the bridge is formed by a pair of dogleg cross-section strips mounted in complementary facing relation and secured to the upper surface of said stem of the T and having flanges facing one another and overlying a portion of the T to form the guideway for a soleplate for mounting the tool.

5. A workbench according to claim 4, wherein the soleplate is of generally square shape and has a slot or slots for the passage of the cutter of the tool.

6. A workbench according to claim 4 or 5, wherein said flanges are provided with a plurality of equally spaced detents and wherein said soleplate carries a member movable relative to said flanges, said member being provided with a spring-loaded element, selectively engageable in one of said detents, to locate the soleplate at a particular position on the guideway.

7. A workbench according to claim 6 and further comprising means to clamp the movable member after it has been located by said springloaded element engaging in one of said detents.

8. A workbench according to claim 7, wherein said means comprises a threaded rod passing through a threaded bore in said member and which is laterally spaced from said spring-loaded element by a distance equal to the spacing between said detents, or a multiple thereof, so that the end of the threaded rod can be screwed into engagement with another of said detents.

9. A workbench according to claim 8, wherein a second threaded portion is formed in a member associated with said soleplate, at a point thereof remote from said threaded bore, and a second threaded rod passes through said second threaded bore whereby the second threaded rod may be screwed into engagement with a further one of said detents.

10. A workbench according to claim 8 or 9, wherein said movable member and said further member are each capable of limited relative movement with respect to said soleplate and is lockable at any position within said limited relative movement

11. A workbench according to any one of claims 3 to 10, wherein the edge of the crosspiece of the T is provided with a plurality of equally spaced detents and wherein a relatively movable stop which is adapted to position the workpiece is provided with a spring-loaded element selectively engageable in one of said detents, to locate the movable stop at a particular position on the crosspiece of the T.

12. A workbench according to claim 11, and including a movable part to said stop which is capable of limited movement with respect to the remainder of the stop to give a fine adjustment of the position of a workpiece engaged against said stop.

13. Apparatus for relative positioning a workpiece to be machined, and a tool for cutting the workpiece, whereby the cut of the tool is produced at a desired modular position, said apparatus comprising an elongate guide having a plurality of equally spaced detents and a relatively movable member adapted to position the workpiece, or the tool, the movable member having a spring-loaded element selectively engageable in one of said detents, to locate the movable member at a particular position on the elongate guide and means to guide the tool or workpiece whereby it can be moved perpendicular to the length of the elongate guide to effect the cut.

14. Apparatus according to claim 13, and further comprising means to clamp the movable member on the elongate support after it has been located by said spring-loaded element engaging in one of said detents.

15. Apparatus according to claim 14, wherein said means comprise a threaded rod passing through a threaded bore in said member, which is laterally spaced from said spring-loaded element by a distance equal to the spacing between said detents, or a multiple thereof, so that the end of the threaded rod can be screwed into engagement with another of said detents.

16. Apparatus according to claim 15, wherein said member is mounted on a tool soleplate adapted to carry a power tool and wherein a second threaded bore is formed in a member associated with said soleplate at a part thereof remote from said through bore in the movable member, a second threaded rod passing through said second threaded bore, whereby the second threaded rod may be screwed into engagement with a further one of said detents.

17. Apparatus according to any one of claims 12 to 16, wherein a movable part is mounted on said movable member for limited relative movement therewith, said movable part being lockable in a particular position within said limited relative movement.

18. A workbench substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

19. Apparatus for relative positioning of a workpiece to be machined, said apparatus being substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings.