GB2179293A - Tooling jig - Google Patents

Abstract

Apparatus for relative positioning of a cutting tool and a workpiece, for producing cut at a desired modular position, comprises an elongate guide (48 or 32) with equally-spaced detents (50 or 52) and a relatively movable member (62 or 110) for positioning the tool or workpiece, the relatively movable member (62 or 110) including a spring-loaded element such as a ball (113) selectively engageable with the respective elongate guide. The position selected may be secured by clamp (116) engaging in an adjacent detent. The apparatus preferably forms part of a workbench in which a bridge (32,34) carried by a fence (38) is pivotally connected to the bench top (12) by brackets (20,22) so as to accommodate different thicknesses of workpiece. <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 baseforsupporting 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 perpendicularto and intersecting the line ofthe straight edge, the guideway being adapted to guide for movement therealong a router accurately perpendicularto 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 pointofview.

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 guidewayon said bridgeforguiding a machinetool, said guideway extending accurately perpendicularto 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 aboutthe pivotal connection, and then lowering the bridge onto the workpiece. The pivotal connection between the fence allows for limited vertical movement of the fence and the bridge, thus to accommodateworkpieces of different thickness. The bridgewill actuallylieflatonthetopof 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 clampfor 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 generallyT-shaped sheet material member, the fence being secured directly to, or formed as part of, the crosspiece ofthe T.

One particularform 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 oftheTand havingflanges facing one another and overlying a portion of the Tto form theguidewayforasoleplateformounting 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 ofthe 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 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.

In orderto ensure firm clamping ofthe 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 th rough said second threaded bore wherebythe 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 arrangments 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 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.

The invention also provides, in this way, apparatus for relative positioning a workpieceto 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, orthe 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 orworkpiece whereby it can be moved perpendicular to the length of the elongate guide to effectthe cut.

In orderthatthe present invention may more readily be understood, the following description is given, merely byway 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; Figure2 is an enlarged perspective view of the workpiece stop oftheworkbench of Figure 1; Figure 3 is a cross-section through the stop of Figure2; 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 6is a plan view of a soleplate ofthe workbench of Figure 1; and Figure 7is a side elevation ofthe soleplate of Figure 6.

Referring firstto Figure 1 ofthe 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 innerframe is mounted a bench top 12 formed of a reinforced plastics material and having an upper working surface 14. Letintothisupperworking surface are two channel section guideways 16,18 which extend from frontto 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 brackets20,22 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 ofthe crosspiece 32 of a generally T-shaped sheet metal member the stem of which is shown at 34 and forms a bridge extending overthe working surface 14.

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

Welded to the upper surface ofthe stem 34 ofthe T-shaped plate are two parallel dogleg cross-section strips 40 and 42 having a generally horizontal lower leg 44, an upstanding part46 and an inwardlyfacing flange 48. The strips 40,42 are arranged parallel to one another and accurately perpendicularto the fence 38. Itwill be seen that each strip is provided with a plurality of equidistantly spaced apertures 50 forming detents. Similarly, the portion ofthe 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 thatthe forward edges oftheflanges 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 underthe 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 secu red by bolts 66.

Each member is provided with an overhanging portion 68,70 defining there-below, withthe upper surface ofthe plate 56, a slot72, 74. The body of the member 60 has a spring-loaded element 76, the spring of which urges the element (usually a ball) downwardlytowards 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 guidewayformed by the strips 40,42 and thatthe sprung-loaded ball 76 will engage in turn in ne ofthe detent holes 50. This defines a particular position ofthe soleplate and allows for modular location ofthe 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 chuckofadrillandallowsthedrill bitty pass downwardlytherethrough andthroughthe 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 spring-loaded 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 forthe 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 aboutthe threaded pivot pin 27 and a workpiece which is indicated at 100, is introduced onto the top ofthe working surface 14. The T-piece is then lowered by hinging aboutthe pivot pins 27 until it lies on top of the workpiece. Depending on the thickness ofthe 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 guidewayformed bythe strips 40,42 as indicated above.The actual location is selectedforthe particular longitudinal saw cut one wishesto 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 ofthe 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 theworkpiece 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 thatthe 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. Forthis 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 ofthe 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 numberal 113 and is urged downwardly by spring 114. The ball is arranged to engage in the detent apertures 52 described previouslyand a clamp 116 can be engaged in an adjacent detent in a similar manner to that described earlier. This again gives a modular positioning ofthe stop, to give a modular length of workpiece when one moves the saw along the guideway formed by the strips40,42. Occasionally one wishes to make a cut which is off module and forthis purpose the stop can be modified as shown in Figure 5 by the provision of an adjustable or movable part 118the position of which, relative to the stop 110, can be changed by slackening of clamps 1 20, 121 and sliding the part 118 relative thereto, this movement being accommodated bytheslots 122,123.

Claims (19)

1. Apparatus for relative positioning a workpiece to be machined, and a tool for cutting theworkpiece, 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, orthe 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 ofthe elongate guide to effect the cut.

2. Apparatus according to claim 1, 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.

3. Apparatus according to claim 2, 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.

4. Apparatus according to claim 3,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.

5. Apparatus according to anyone of claims 1 to4, wherein a movable part is mounted on said movable memberfor limited relative movement therewith, said movable part being lockable in a particular position within said limited relative movement.

6. 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.

7. Aworkbench comprising a support having a working surface, a fence pivotally mounted on said support and normally extending above said working surface,wherebythe rear edge of a workpiece placed on said working surface can be abutted against said fence, a bridge carried by said fence to overlie said workpiece, a guideway on said bridge for guiding a machine tool, said guideway extending accurately perpendicularto 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 sufficient limited vertical movement of said fence and bridge, to accommodate different thicknesses of workpiece.

8. Aworkbench according to claim 7, wherein the pivotal connection comprises a bracket on each side of the support having a generally upwardly extending slottherein, a slider in each slot and a pivot pin passing through, orformed 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.

9. Aworkbench according to claim 7 or 8, 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.

10. Aworkbench according to claim 9, 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 oftheTto form the guidewayfor a soleplate for mounting the tool.

11. Aworkbench according to claim 10, wherein the sole-plate is of generally square shape and has a slot orslotsforthe passage of the cutter of the tool.

12. Aworkbench according to claim 10 or1 1, 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.

13. Aworkbench according to claim 12 and further comprising means to clamp the movable member after it has been located by said spring-loaded element engaging in one of said detents.

14. Aworkbench according to claim 13, 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 thatthe end of the threaded rod can be screwed into engagement with another of said detents.

15. Aworkbench according to claim 14, 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 engagementwith afurtheroneofsaid detents.

16. Aworkbench according to claim 14 or 15, wherein said movable member and said further member are each capable of limited relative movementwith respect to said soleplate and is lockable at any position within said limited relative movement.

17. Aworkbench according to any one of claims 9 to 16, 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 ofthe T.

18. Aworkbench according to claim 17, 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.

19. Aworkbench substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.