WO1996000638A1

WO1996000638A1 - Saw bench

Info

Publication number: WO1996000638A1
Application number: PCT/AU1995/000392
Authority: WO
Inventors: Trevor Tisdall
Original assignee: Trevor Tisdall
Priority date: 1994-06-29
Filing date: 1995-06-29
Publication date: 1996-01-11

Abstract

A saw bench for combined drop and radial saw function. The saw bench includes a saw carrier (4) that can support a circular saw above a working surface (7). The saw carrier is slidably supported from a guide (1, 2), whereby a radial saw function is achieved. The guide (21, 22) is pivotable relative to the working surface so that a drop saw function can also be achieved. Preferably the pivoting allows for the carrier to be inverted so that a table saw configuration can be achieved with the underside of the carrier acting as the table. Biasing means (25) acts to force the guides (21, 22) out of contact with the workpiece and preferably allows the inverted configuration. The carrier (4) can be locked into fixed positions via a bolt and wingnut arrangement (30).

Description

SAW BENCH

FIELD OF THE INVENTION

The present invention relates to a saw bench of the type that can change configuration to allow for more than one type of sawing function.

BACKGROUND OF THE INVENTION

Specific saws are known in woodworking and in other work such as in the cutting of metal and perhaps stone to perform specific functions. Three types of functions are most commonly used for circular saws. One common type of saw is a table saw where a driven cutting blade protrudes from underneath a slot in a table in a fixed position, so that work pieces can be moved across the fixed blade and cut or grooves formed thereinto. The movement of the article is usually guided by fences along which the article is slid. A second commonly used saw is a radial arm saw, wherein a saw is held above a work bench, and supported on guide(s) that allow movement of the cutting blade across the workpiece, such movement may involve either a pushing or pulling by the operator. A third type of commonly provided saw is a drop saw (also known as a mitre saw), wherein the saw blade is supported for pivotable movement relative to the work bench so that the saw can be lowered onto the workpiece.

A person who wants to perform all of these functions with a workpiece is faced with the need to purchase a variety of different saws to perform these functions. Where a substantial amount of work is done the purchase may be warranted however in many circumstances where a modest amount of work is done, or where economic circumstances do not allow purchase of several machines it becomes desirable to purchase one piece of equipment that can change its configuration to perform all of the commonly required sawing functions.

Where different sawing functions are to be used on one workpiece it is desirable that the configuration can be changed efficiently. The efficiency of change of configuration is particularly relevant to a change in configuration from one where the saw blade is supported above a work surface to a second where the saw is supported from below the work surface.

Several proposals for saw benches that can change configuration have been made. Australian Patent specification 14848/83 by Lewin shows a work bench providing a removable saw supported to be operable above a work bench surface as a radial arm saw, and then from underneath the work bench surface as a table saw. The difficulty with this proposal is that inversion of the saw is still somewhat awkward despite being an improvement over an earlier proposal by the same inventor. The inversion of the saw involves aligning a pair of runners of a saw carrier with a pair of apertures extending up through a pair of guides, and rotation of the saw supporting plate and the saw over 180 degrees so that the runner then can be dropped through a second pair of apertures extending through the pair of guides. The pivot is relatively unsupported. The change in configuration also requires the change in position of the working surface, which takes the form of a plate that needs to be unfastened from the bench frame and repositioned. The length of the guides must also be at least twice the size of the saw carrier. Additionally the saw described in this document has no provision for a drop saw function.

One aspect of the present invention is particularly directed to a combination of radial arm saw and drop saw.

The combination of a radial arm saw and drop saw is described elsewhere, for example in Australian Patent application 11250/92 by Black & Decker. That document describes an apparatus having a pair of guides upon which a saw motor and blade is slidably supported. The guides are supported by a vertical machined shaft, as well as a horizontal machined shaft, on a work bench. The saw can be moved along a guide above the work table to act as a radial arm saw, and can be pivoted about the horizontal shaft to act as a docking saw. Complex manoeuvring is required for inversion of the saw to where the saw is supported beneath the table; the saw needs to be rotated about both the vertical shaft as well as the horizontal shaft The use of the arrangement of a single horizontal shaft acting as a guide as shown also requires quite high tolerance machining during manufacture, and requires the whole apparatus to be constructed such that it is quite a heavy piece of equipment.

The docking saw function as shown in the above Australian patent specification is provided by a pivot on the saw carrier. One difficulty with this arrangement is that it is quite awkward to put large workpieces onto the bench. The limitation provided by having guides extending over the workbench top can be of considerable inconvenience.

Additionally it may be desired to have the driven saw detachable from the workbench so that it might be used separately from the work bench as a portable saw. Generally space may also be a difficulty and therefore it is generally desirable to have the workbench foldable so that it can be stored compactly when not in use, and conveniently the workbench is also lightweight

Other proposals have also been made to achieve combination saws. For example Australian Patent 11250/92 in the name of Black & Decker provides for a saw that can act as both a docking saw, a bench saw as well as a radial arm saw.

A pair of guides upon which a saw motor and blade are slidably supported, are themselves supported by a vertical machined shaft, as well as a horizontal machined shaft, on a work bench. The saw can be moved along the pair of guides above the work bench to act as a radial arm saw, and can be pivoted about the horizontal shaft to act as a docking saw. In order to provide for inversion of the saw to where the saw is supported beneath the table the saw needs to be rotated about both the vertical shaft as well as the horizontal shaft. The use of the arrangement of single shafts also requires quite high tolerance machining, and requires the whole apparatus to be constructed such that it is quite a heavy piece of equipment

A similar mechanism of changing the position of the saw from being above a working surface to being below the working surface is shown in German Patent DE3134086, although in that proposal a radial arm saw is not suggested.

OBJECT OF THE INVENTION

It is an object of this invention to provide a saw bench for combined drop and radial circular saw functions that obviates or minimises at least one of the aforementioned problems in a simple yet effective way, or at least provides the public with a useful choice.

It is a object of a specific form of this invention to provide a sawbench for combined drop and radial saw functions that can be constructed in a lightweight fashion.

It is an object of a further specific form of this invention to provide a sawbench for combined drop and radial saw functions onto which a portable circular saw can be mounted for use. An object of an even further form of this invention is to provide a saw bench for combined drop, radial arm, and fixed table circular saw operations that obviates or minimises at least one of the aforementioned problems in a simple yet effective way, or at least provides the public with a useful choice.

SUMMARY OF THE INVENTION

In a broad form and not necessarily the broadest or only form the invention could be said to reside in a saw bench for combined drop and radial saw functions, said sawbench including a saw carrier for supporting a circular saw above a working surface, said carrier being slidably supported from at least one guide for radial saw functions, said at least one guide being pivotal with respect to the working surface to provide a drop saw function.

In preference the saw bench includes biasing means to bias the at least one guide to a raised position. The extent of raising will vary, but will at least be such that the saw blade supported by the saw carrier is out of contact of the workpiece, and preferably brings the guides clear of the work surface to provide unobstructed access to the working surface. This biasing of the at least one guide to a raised position has an advantage in that the saw is generally in a work ready position when not in use.

The biasing means can be provided by one or more tension springs connected to a first end of the guide, or member connected to the guide at the first end, (opposite to the free end) of the guide, the guide being pivoted about an axis spaced toward the free end of the guides with respect to the spring so as to provide an amount of leverage on the guide by the spring, said tension spring being connected to draw the first end of the guide toward the working surface and thereby draw the free end of the guide away from the working surface. Other spring arrangements may also be used, for example, certain arrangements of compression spring may be used, or the spring may be a pneumatic spring.

The biasing means may also be provided by a counterweight on the guide or member attached to the guide at or near the first end of the guide.

The bias provided by the biasing means could be such the guide is biased to lift the guide together with saw carrier and mounted saw only when the saw is close to or at the first end of the guides. This would ensure that any vertical movement of a potentially exposed rotating circular saw blade is well away from an operator of the saw bench. In a preferred form there are provided two guides each spaced apart and connected in the spaced apart position and the saw carrier guided between the guides. The thus formed guides could be formed from sheet metal, or alternatively from extruded aluminium or alternatively may be formed from tubing which is preferably of hollow cross section which may conveniently be circular. This configuration permits a quite stable support for the saw carrier whilst allowing for lightweight construction. This configuration also preferably includes torsion inhibiting means to inhibit torsion about an axis in the direction of movement of the saw carrier.

The guides preferably have a first cross member connecting the guides at a first end of the guides.

The torsion inhibiting means may be a second cross member, extending between the guides spaced away from the first cross member. Alternatively the first cross member includes at least one deep flange transverse to the guides, which flange supports the guides against torsional effects. Alternatively stays may be provided between the first cross member and the guide members.

A support frame is preferably provided to support the working surface at a working height. The support frame is preferably lightweight and may be provided by tubular steel construction. Legs on which the support frame is held are preferably collapsible so that the bench can easily be packed away and take up minimal space.

Preferably the work surface is constructed from sheet metal and includes slots arcuately placed with respect to the direction in which elongate workpieces would he, a fence engaging the arcuate slots is slidable guided by said slots so that workpieces can be held at varying angles with respect to the saw blade, and therefore the saw bench can be also used to produce mitre cuts.

Instead of providing for adjustment of the position of the circular saw blade relative to the working surface and work piece, the work piece is positioned relative to the fixed workpiece and accordingly the construction of a shaft that can be rotated about its longitudinal axis need not be made. This enables the provision of a mitre function using lightweight construction techniques and not requiring high precision machining of a shaft and corresponding journal. It is preferred that the saw carrier has mounting means to mount a portable saw thereto, although it is to be understood that forms of the invention may encompass a dedicated saw unitary in construction with the saw carrier.

It is also preferred to have lock means to lock the carrier into fixed positions along the at least one guide.

In an alternative form the invention could be said to reside in a saw bench including a saw carrier for supporting a circular saw slidably supported between a pair of spaced apart guides a first surface of said saw carrier being usable as a bench for the bench saw and an opposite second surface adapted for fastening the circular saw, said carrier having a slot for passage therethrough of a peripheral portion of a saw blade of the saw the pair of guides supported above a support frame so as to be pivotable about a generally horizontal axis with respect to said support frame, between two positions, a first position wherein the saw carrier is positioned so that the saw blade extends downwardly from above the workpiece, and a second position wherein the saw carrier is positioned so that the said blade extends upwardly from below the workpiece a second working surface supported from the support frame, and below the guides said second working surface being adjustable vertically at least two connections providing the pivotable support, a respective one connection being made to each of the guides and being so positioned that when the saw carrier is positioned at a first end of the guides that it is stably supported by the support frame when in either of the said two positions.

To assist with the understanding of the invention one embodiment is illustrated. It is to be understood from the foregoing that the illustrated embodiments of the invention are merely illustrative and in no way restricts the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

To assist with the understanding of the invention several embodiments are illustrated. It is to be understood from the foregoing that the illustrated embodiment of the invention is merely illustrative and in no way restricts the scope of the invention.

In the illustrations: FIG. 1 Is a partly exploded perspective view of the first illustrated embodiments of the saw bench ready to support a removable saw from above, where (a) shows the majority of the saw, (b) shows in greater detail the saw carrier and a means for fastening a circular saw (c) shows some detail of the mechanism for lowering and raising the working surface, (d) shows detail of the construction of a fence for supporting a workpiece at a range of angles to the radial arm or the drop saw, and (e) shows in greater detail the locking mechanism for locking the saw carrier into a fixed position along the guides,

FIG. 2 is a perspective view of where the saw bench is ready to support a circular saw below a working surface, in a configuration for use as a bench saw,

FIG. 3 is a schematic plan view of from one side showing the guides in a lowered position and some way through radial movement,

FIG. 4 is a schematic plan view from one side showing the guides in a raised position, clear of the work surface,

FIG. 5 is a schematic plan view from one side showing more detail of the arrangement for connection of the springs to the guide,

FIG. 6 Is a partly exploded perspective view of the first illustrated embodiments of the saw bench ready to support a removable saw from above, where (a) shows the majority of the saw, (b) shows in greater detail the saw carrier and a means for fastening a circular saw (c) shows some detail of the mechanism for lowering and raising the working surface, and (d) shows detail of the construction of a fence for supporting a workpiece at a range of angles to the radial arm or the drop saw ,

Figure 7 is a perspective view of the second embodiment where the saw bench is ready to support a circular saw below a working surface, ina configuration for use as a table saw,

FIG. 8 is a schematic plan view of from one side showing the guides in a lowered position and some way through radial movement,

FIG. 9 is a schematic plan view from one side showing the guides in a raised position, clear of the work surface, and FIG. 10 is a schematic plan view form one side showing more detail of the arrangement for connection of the springs to the guide.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

Dimensions of certain of the parts as shown in the drawings may have been modified and/or exaggerated for the purposes of clarity of illustration.

DETAILED DESCRIPTION OF THE DRAWINGS

The illustrated embodiments of the saw bench provide for at least two configurations in which the saw is supported above the workpiece as either a radial arm saw or a drop saw. A third configuration is also possible where the guides are pivoted over 180° so that the support for the saw is inverted and the saw is supported below its carrier which acts as a work surface.

The saw bench comprises a pair of spaced apart saw guides (1,2) that are supported above a generally horizontal support frame (3). A saw carrier (4) is slidable between the saw guides and is used to support a portable circular saw. The guides (1,2) are so supported as to be pivotable with respect to the support frame (3).

A working surface (7) is supported by the support frame (3) in a position that is below the guides (1,2) and is adjustable vertically, so as to appropriately support a workpiece when the saw is supported above the workpiece.

Four collapsible legs (8,9,10,11) support the supporting frame (3), two of which legs (8, 9) have wheels (12) contactable with the ground so that the saw bench can be wheeled to a desired position. Stays (24) support the legs in position, the stays are foldable with a stop such that the weight of the bench maintains them in an open position. Pivots (50) are folded upwardly to collapse the stays and legs. Wheels (12) can also be used for moving the saw bench around when in the folded configuration.

Turning now specifically to the first embodiment illustrated in Figures 1 and 2.

The support frame (3) is constructed of generally box section tubular steel, welded together to take on a rectangular shape. Two, upwardly extending, sheet metal, guide supports (13, 14) are fastened to a first end of the rectangular support frame. The guide supports may be attached to the support frame either by use of fasteners, or by welding or brazing. Each of the guide supports is made rigid by the provision of end walls (16, 17). Identical end walls (not shown) are formed on opposite sides of the sheet metal, guide supports. A guide support frame member (18) is attached to an uppermost portion of each of the guide supports. The guide support frame member, need not be present and may suitably be replaced by the sheet metal of the guide supports being folded over.

The guides each comprise an inwardly facing C section channel, which are supported apart from one another by a square steel tube (19) welded to a first end of both C- section channels and a tubular handle (20) welded towards a second end of both of the C-section channels.

A respective pivot pin (21 22) passes through a respective guide and through a respective guide support frame member (18). The pivot pins extend through the guides at a position away from the first end, of the guides. In the first embodiment shown in Figures 1 and 2, one connecting spring (25) is connected between the square steel tube cross member (19) or member (90) extending from said member and the support frame. In a second embodiment shown in Figures 3, 4 and 5, one extension member (90) is operably connected to each of the guides by pivot pins (21, 22). A lateral catch (91) extends from the extension member to catch onto a respective guide to engage the guide with the spring. Two springs are provided - one for each extension member (90). This arrangement shown in the second embodiment facilitates free movement of the connection between the spring and the guides. The member is able to move about 60° with respect to the guides. The connecting spring is a tension spring which because the pivot pins are positioned away from the first end of the guides biases the first end of the guides downwardly, and consequently biases the free end of the guides upwardly. The bias may be such that it will only act to lift the guides to a raised position if the carrier together with the mounted circular saw is close or at the first end of the guides. The weight of the saw at the free end of the guides being too great for the spring to lift This is a feature that provides a considerable safety advantage, because the saw will only be lifted out of the way when the saw is at least partially retracted to the first end of the guides, and therefore some way away from an operator of the saw.

Turning back specifically to the first illustrated embodiment. The saw carrier can be used to mount a variety of tools and can be removed and replaced with another saw carrier that already has that tool fixed into position. The carrier (4) consists of a rectangular tray formed from sheet metal that has an inverted skirt extending upwardly from a base. The base has a slot (26) cut into it Nylon wheels (80) are supported by the inverted skirt and engage the C section chanels, to support the carrier between the guides. The carrier has a clip (27) that retains the front of the saw base plate. It has two adjustable stops (28) to locate the portable saw in the correct position. The portable saw is locked into position by means of a clip (29) and a single bolt and wing nut (30). The saw carrier can be locked into a number of suitable positions on the saw guides by means of the pin (31). This pin consists of a U shaped piece of cylindrical stock with one leg of the U longer than the other. The long leg is biased outwardly to engage suitably located holes in the saw guides by means of a washer (61) positioned by a split pin (62) on the long arm of the pin urged by a spring (63) away from a post (64) attached to the carrier as is best seen in Figure. 1 and labelled (e).

The working surface (7) consists of a rectangular sheet metal tray whose sides form guides for the sliding frame (40). The working surface can be moved vertically by means of four pivoted legs (70) each lateral pair of which forms a parallelogram with the sliding frame (40) and the main frame. The sliding frame can be moved horizontally with regard to the working surface (7) by means of threaded stock (71) that engages an appropriately threaded hole (72) in the cross member (73) of the sliding frame. This threaded stock is turned by means of a handle (74). The relative movement of the sliding frame to the working surface changes the angles in the previous mentioned parallelogram and consequently cause the second working surface to move up or down. The working surface is constrained horizontally by means of two hooks (75) that engage two suitable formed guides on the inner edges of the sheet metal guide supports (13 and 14). These hooks may also be used to lock the second working surface into any vertical position by means of two wing nuts (76) that are situated on either side of the front of the work table.

The saw can be operated as a drop saw and as a radial arm saw, as best seen in Figure 3 for the second embodiment In the drop saw mode, the saw is angled above the table and may be brought down to make a cut by means of downward pressure on the handle(20) as seen in Figure 4.

The feature of a drop saw and radial arm saw combination facilitates the maximum use of space because the circular saw need not be positioned to one side of the workpiece to be drawn through the workpiece but the workpiece can be positioned directly below the saw blade, which can be brought down and plunged into the workpiece, and then drawn or pushed across to act as a sliding compound mitre saw. The ability to lift the guides away from the work surface also facilitates the placement of workpieces on the working surfaces, in that fixed guides or other obstructions do not need to be avoided and workpieces can be lowered directly onto the work surface.

The working surface contains a number of concentric arcuate slots (50) that allow the fence carrier (51) to rotate about the threaded pivot A. The fence carrier is located under the work table and the two sections (52) of the fence slides onto the four threaded bolts (53) that consequently protrude through the table. The two halves of the fence can be locked into any position from 90 degrees to 45 degrees relative to the motion of the saw by tightening wing nuts (54) that are screwed onto these bolts. This enables mitres to be cut into a workpiece. In combination with the facility of a drop saw, and the facility of a radial arm saw together with the feature of the fence that can be guided by the arcuate slots obviates the need for a solid vertical shaft to support a circular saw, so that the saw itself can be rotated, as is presently conventional. Instead the workpiece is rotated relative to the saw. Where the angle is relatively great the circular saw may need to be positioned away from the first end of the guides, so that it is aligned with the workpiece, and can be dropped directly to cut the workpiece at an appropriate angle. This is preferably where several similar pieces are to be cut Alternatively the saw may be drawn from the first end of the guides through the workpiece that is held at the desired angle.

As alluded to above the illustrated embodiments of the saw bench provide for three configurations; two in which the saw is supported above the workpiece as either a radial arm saw or a drop saw, and a third configuration in which the support for the saw is inverted so that the saw is supported below the workpiece as a bench saw.

The illustrated saw bench provided for easy change over from functions where the saw is supported above the workpiece, to where the saw is positioned below the workpiece. As discussed above the saw carrier (4) is slidable within the saw guides and is used to support a portable circular saw on one surface (5) and an opposite surface (6) of the saw carrier is of such dimensions that it is adapted to act as a second working surface. The guides (1,2) are so supported as to be pivotable with respect to the support frame (3) that in a first position (shown in Figure 1) the circular saw is supported above a work piece and in a second position (shown in Figure 2) the circular saw is supported from beneath the work piece. A respective pivot pin (21 22) passes through a respective guide and through a respective guide support frame member (18). The pivot pins extend through the guides at a position away from the first end, of the guides, and when taken relative to the guide supports and the support frame are spaced away from their first ends, so that the saw supporting plate when place up against the first end of the guide, is still stably supported above the support frame, when the saw supporting plate is either above or below the workpiece.

The guides can be locked into position by means of a spring-closed, generally U shaped pin (23) a longer arm of which passes through the guide support and at least one of the C-section channels of the saw guides. The construction of this spring-closed pin is identical to the pin for locking the saw carrier into the guides, which is described below and illustrated in Figure llabelled (e). The C-section has two holes, a first of which is at the end of the C-channel so that the pin can pass therethrough when the guides are in a first position, and a second of the holes being positioned towards the centre of the C- channel so that the pin can pass therethrough when the guides are inverted.

The saw guides can thus be swung through 180 degrees to convert from a radial arm saw as shown in Figure 1 to a table saw as shown in Figure 2.

The third embodiment illustrated in figures 6 to 10 is constructed similarly to the first embodiment but with different material, and tubular metal frame members of circular cross section are used in its construction. The following descrption highϋghs differences between the two.

The spaced apart saw guides (1,2) are made of tubular metal construction, being circular in cross section. The two guides are supported apart from one another by a square steel tube (19) welded onto a first end of both of the tubular metal guides. Alternatively the saw guides might be made up of the tubing of circular cross section in a U shaped configuration, the closed part of the U acting in place of the square steel tube. In this embodiment the circular cross section tubing has a diameter of 38mm and a wall thickness of 1.6mm.

The saw carrier is also constructed to assist with keeping the guides spaced apart The saw carrier (4) is slidable between the two saw guides. The carrier as with the first embodiment consists of a rectangular tray formed from sheet metal that has an inverted skirt extending upwardly form a base with a slot (26) cut in it. The carrier includes a plurality of aligned ridges (112) pressed into the sheet metal of the carrier base. Two tubular guide engaging members (100, 101) are supported apart from the skirt of the carrier, on one side by an extension of the skirt (102) and on an opposite side by a further sheet metal support member (103) upon which they are spot welded. The guides pass through the guide engaging members. The diameter of the tubular guide engaging members is 47.8mm and inside the tubing are positioned nylon tubes, to facilitate the sliding action. This support arrangement provides for a positive fit over the guides, and the elongate nature of the guide engaging members assists with resisting twisting, or torsional distortions of the guide members.

Should it be desired to maintain the saw carrier at a given position along the saw guides, a bolt (107) is engaged within a threaded aperture in the tubular guide engaging member (100), which bolt can extend through the aperture and bear against the guide.

The means for holding a portable saw in place on the carrier is also different to that illustrated in the first embodiment A pair of longitudinal position members (113, 114) are positioned to define the ends of the portable saw, with the position members fastened to the carrier by means of fasteners passing through apertures in the clamp members (not shown) and spaced apart apertures (115) formed in the base of the carrier. Transverse position members (116) can be positioned into place along the longitudinal position members and fastened by screw threaded fasteners passing through slots (117) in the longitudinal position members and apertures (118) in transverse position members. The slots allow for adjustability of the width. The portable saw can thus be accurately positioned every time it is used, a fastening clip, (not shown) can be clipped form a respective end of the portable saw engaging over a respective recess (119) of a respective longitudinal position member.

The slot (26) in the carrier through which a periphery of the saw blade passes is relatively wide, to allow for a range of positions, however, it is undesirable to have such a wide slot when in use, because otherwise narrow workpieces may be drawn into the slot when working as a table saw. Accordingly throat plates can be positioned under the portable saw and over parts of the slot to make the slot narrower. These throat plates (not shown) may engage with the two rebated ledges (120, 121) adjacent to the slot.

The support frame (3) in the third embodiment is constructed of tubing of similar diameter to the tubing of the guides, to form a generally rectangular support frame, except that the support frame is open at a first end thereby forming a generally U shaped frame. The free ends of the support frame are bent upward to respectively form the two upwardly extending guide supports (13,14). Vertical stays (104, 105) give the guide supports further support, to withstand heavier loads. Additionally the vertical stays operate in much the same way as the sheet metal guide supports of the first embodiment, in that the working surface (7) is constrained horizontally by means of two hooks that engage the two vertical stays so that the working surface can be lifted and maintain in a vertical position. The mechanism for providing lift is substantially identical to that of the first embodiment. The four pivoting legs (70) of the lifting mechanism are attached to a rail that is welded to the top of the vertical frame member instead of directly to the tubular frame member. This is simply to maintain some accuracy of movement, which might otherwise be lost by the difficulty of accurately attaching the pivoting legs to the tubular frame of circular cross section. It can be seen that the sliding frame is somewhat modified relative to that shown for the first embodiment in that the cross member (73) is formed simply from a flat web of metal, and the threaded stock engages with a correspondingly threaded block ( 110) attached to an upper surface of the cross member (73). Additional in place of a continuous slide on either side of the sliding frame two spaced apart smaller slides (111) are provided on either side.

The respective pivot pins (21, 22) pass through a respective guide support. The pivoting mechanism however is different to that shown in the first embodiment and is more like that shown in the second embodiment, so that the spring engages with the guides only when the saw is positioned above the working surface (7) such that extension member (90) engages the lateral catch (91) at the first end of the guides.

To maintain the inverted position of the saw, that is, where saw blade protrudes upwardly, a simple stop present on the support frame is used to limit the pivoting of the saw guides, and to support the saw carrier and saw in its inverted position.

The construction of the working surface (7) is also somewhat modified relative to that shown in the first embodiment. In particular a longitudinal cutting slot (130) is formed along the entire length of the working surface. Flanges depend angularly from the surface of the longitudinal cutting slot so that the slot defines a dove-tail cross section. A replaceable support can be slid into the cutting slot, for example some press-board suitably shaped may be used. Thus where the saw blade is to cut through timber, it can pass right through the timber without damaging the working surface (7). The replaceable support can be thrown out when it is too damaged. The fence carrier (51) of this embodiment includes a central depression (133) so that the longitudinal cutting slot can be avoided.

The third embodiment is constructed such that the saw carrier is considerably wider than that of the first embodiment, so that the surface of the opposite side of the carrier (6) is much greater and allows for greater capacity in the configuration of a bench saw.

Claims

CLAIMS:

1. A saw bench for combined drop and radial saw functions, said saw bench including a saw carrier for supporting a circular saw above a working surface, said carrier being slidably supported from at least one guide for radial saw functions, said at least one guide being pivotal with respect to the working surface to provide a drop saw function.

2. A saw bench as in claim 1 wherein the saw carrier is pivotable through at least 180° so that an underside of the saw carrier can act as a further working surface.

3. A saw bench as in claim 1 wherein the saw bench includes biasing means to bias a free end of the at least one guide to a raised position such that the saw blade supported by the saw carrier is out of contact of the workpiece.

4. A saw bench as in claim 3 wherein the raised position is such that the free end of the at least one guide is brought clear of the work surface to provide an unobstructed access to the working surface.

5. A saw bench as in claim 3 wherein the biasing means is one or more springs operably connected to the at least one guide.

6. A saw bench as in claim 3 wherein the biasing means includes a counterweight on the guide or member attached to the guide at or near the first end of the guide.

7. A saw bench as in claim 3 wherein the biasing means is one or more tension springs connected to a first end of the guide, or member connected to the guide at a second end of the guide being proximal to a pivot axis of the guide, the guide being pivoted about an axis spaced toward the free end of the guides with respect to the spring so as to provide leverage on the guide by the spring, said tension spring being connected to draw the first end of the guide toward the working surface and thereby draw the free end of the guide away from the working surface.

8. A saw bench as in claim 3 wherein the bias provided by the biasing means is such that the guide is biased to lift the guide together with saw carrier and mounted saw only when the saw is close to or at the end of the guides proximal to a pivoting axis of the guides.

9. A saw bench as in claim 1 wherein two guides are provided each being spaced apart from one another and connected in the spaced apart position and the saw carrier guided between the guides.

10. A saw bench as in claim 9 wherein the two guides are formed from folded sheet metal.

11. A saw bench as in claim 9 wherein the two guides are formed from extruded aluminium.

12. A saw bench as in claim 9 wherein the two guides are formed from tubular metal of hollow cross section.

13. A saw bench as in either claim 9 including torsion inhibiting means to inhibit torsion about an axis in the direction of movement of the saw carrier.

14. A saw bench as in claim 9 the guides preferably have a first cross member connecting the guides at the pivot proximal end of the guides.

15. A saw bench as in claim 9 wherein the torsion inhibiting means may be a second cross member, extending between the guides spaced away from the first cross member.

16. A saw bench as in claim 9 wherein the first cross member includes at least one deep flange transverse to the guides, which flange supports the guides against torsional effects.

17. A saw bench as in claim 12 wherein the carrier engages each of the guides with a respective tubular member encircling the respective guide.

18. A saw bench as in claim 1 including a support frame to support the working surface at a working height

19. The saw bench as in claim 18 wherein die support frame lightweight, and is provided by tubular steel consttuction.

20. The saw bench as in claim 18 wherein legs on which the support frame is held are collapsible.

21. The saw bench as in claim 1 wherein the work surface is constructed from sheet metal and includes slots arcuately placed with respect to the direction in which elongate workpieces would lie, a fence engaging the arcuate slots is slidably guided by said slots so that workpieces can be held at varying angles with respect to the saw blade, and therefore the saw bench can be also used to produce mitre cuts.

22. The saw bench as in claim 1 wherein the saw carrier has mounting means to mount a portable saw thereto.

23. The saw bench as in claim 1 wherein a saw is unitary in construction with the saw carrier.

24. The saw bench as in claim 1 including lock means to lock the carrier into fixed positions along the at least one guide.

25. A saw bench including a saw carrier for supporting a circular saw slidably supported between a pair of spaced apart guides a first surface of said saw carrier being usable as a bench for the bench saw and an opposite second surface adapted for fastening the circular saw, said carrier having a slot for passage therethrough of a peripheral portion of a saw blade of the saw the pair of guides supported above a support frame so as to be pivotable about a generally horizontal axis with respect to said support frame, between two positions, a first position wherein the saw carrier is positioned so that the saw blade extends downwardly from above the workpiece, and a second position wherein the saw carrier is positioned so that the said blade extends upwardly from below the workpiece a second working surface supported from the support frame, and below the guides said second working surface being adjustable vertically at least two connections providing the pivotable support a respective one connection being made to each of the guides and being so positioned that when the saw carrier is positioned at a first end of the guides that it is stably supported by the support frame when in either of the said two positions.