GB2362128A

GB2362128A - Shoe cum shroud for a hand held circular saw

Info

Publication number: GB2362128A
Application number: GB0009512A
Authority: GB
Inventors: Anthony Ian Pinder
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-17
Filing date: 2000-04-17
Publication date: 2001-11-14
Also published as: GB0009512D0

Abstract

An adjustable shoe cum shroud is attachable to a hand-held circular saw 200 for reducing the discharge of saw dust into the ambient environment when cutting. It a first part 20 to be secured to the saw body in close proximity to the underside, and a second part 30 having an underside to be located on a surface to be cut. The first and second parts have slots 40, 90 for the saw blade 230 to penetrate. The second part is pivoted to the first part about an axis 120 disposed to one side and substantially parallel to the slots and therefore to the saw blade when the adjustable shoe cum shroud is operably assembled to a circular saw. A shroud means 320a is used to close the gap between the first and second parts when the first part is tilted relative to the second part. A guide system for the saw when mounted on the shoe cum shroud has two parallel runners between which the shoe cum shroud can slide. The runners are mounted on a base which also mounts material alignment means. (Figure 10, not shown).

Description

2362128 AN ADJUSTABLE SHOE CUM SHROUD FOR A HAND-HELD CIRCULAR SAW The

present invention relates to hand-held circular saws and, more particularly, to an adjustable shoe cum shroud which can be used, when making a bevelled cut, in place of the conventional guide shoe or base plate fitted to the saw, and which is intended to reduce the discharge of saw dust into the ambient environment.

A conventional hand-held circular saw includes a main body or casing which houses an electrical motor for driving the saw blade. The saw blade is detachably mounted on the end of the motor drive shaft within a guard or shroud in the saw body. The blade projects downwardly from the saw body, through a slot in a guide shoe or base plate adjustably mounted beneath the saw body. The underside of the shoe defines a planar reference surface beneath which the saw cuts. The shoe may comprise a slotted plate or an open work frame.

In use, the operator holds the saw by a handle attached to the saw body, and advances the saw, relative to the material to be cut, with the planar underside of the shoe resting and sliding on the surface of the material to maintain the required angle and depth of cut of the saw blade. The shoe is articulated to the saw body so as to permit the plane of the saw blade to be tilted relative to the planar underside of the shoe for adjustment of the angle of cut, and to permit the distance by which the saw blade projects below the planar underside of the shoe to be varied for adjustment of the depth of cut.

With the adjustable mounting of the shoe, gaps exist between the underside of the saw body and the-,upper surface of the shoe where the shoe is a plate. There is a large opening in the upper surface of the shoe if the shoe is of frame construction. During use, as the saw is advanced, the direction of rotation of the saw blade is such that the saw teeth cut through the material upwardly from below, thereby spraying saw dust upwardly from the cut, 2 through the aforementioned gaps or opening and into the ambient environment. Furthermore, since a side of the saw body has an opening to enable the saw blade to be easily changed, saw dust is also sprayed out from this opening.

Thus, a problem with existing saws and shoes is that a significant portion of the saw blade above the material being cut is exposed, allowing saw dust to be released into the ambient environment. Tilting of the saw blade from the perpendicular and relative to the shoe so as to incline the cut, and/or raising the blade to reduce the depth of cut, enlarges the gaps and exaggerates the problem.

With a view to alleviating the problem, a source of vacuum may be attached to a socket in the saw body to extract saw dust. However, in practice, a significant amount of saw dust is still sprayed into the ambient environment, requiring the user to wear protective clothing, such as a face mask or helmet and overalls. These can be uncomfortable to wear. Also, other people and property in the vicinity are not protected from the saw dust.

Hand-held circular saws are used by people, such as, shop fitters and DIY enthusiasts. The saws are used for cutting sheets or flatboards which may be formed from such as wood, plies and plastics or compound materials.

Medium density fibreboard NDF) is a relatively new compound material which is extensively used because a high quality finish may be achieved when it is sawn, routed or painted. However, fine chemical spores may be released into the atmosphere when such material is cut, which may be harmful if inhaled.

It is an object of the present invention to provide an adjustable shoe cum shroud for use with a circular saw when making a bevelled cut and which is intended to reduce the discharge of saw dust into the ambient environment.

According to one aspect of the present invention, there is provided an adjustment shoe cum shroud for attachment to a hand-held circular saw for reducing or minimising the discharge of saw dust into the ambient 3 environment when cutting, comprising:

a first part adapted to be secured to the saw body in close proximity to the underside of the saw body, and a second part having an underside which is intended to be located on a surface to be cut, the first and second parts having first and second slots for the saw blade to penetrate, and the second part being pivoted to the first part about an axis disposed to one side of the first and second slots and substantially parallel to the slots and therefore to a saw blade when the adjustable shoe cum shroud is operably assembled to a circular saw; and shroud means for substantially closing the gap between the first and second parts when the first part is tilted relative to the second part.

Since, in use, the first part remains fixed to the underside of the saw body irrespective of the adjustment of the saw blade, the gaps which exist, in the above described conventional arrangement, between the shoe and the saw body, or the opening which exists in the shoe, may be eliminated or significantly reduced, and the gap which is formed between the first and second parts, when mutually pivoted to adjust the tilt of the saw blade, is effectively closed by the shroud means. Thus, the adjustable shoe cum shroud serves to shroud the part of the saw blade above the material to be cut.

The invention also consists in an adjustable shoe cum shroud as defined above which is an integral part of a hand-held circular saw.

The shroud means of the adjustable shoe cum shroud may be configured to extend from the pivotable interconnection between the first and second parts and about the first and second slots. It may include at least one hollow wedge, whereby the degree-, of the angle of tilt of the first part relative to the second part may be adjusted by varying the number of superimposed wedges used, and/or the wedge angle of the or each wedge. In this event, the shroud means may serve to support the first part when pivoted, i.e. tilted, relative to the second part.

4 The shroud means may be in the form of a resilient member for closing the gap between the first and second parts whilst accommodating a range of adjustable included angles between the first and second parts.

Adjustable angle clamping means may be provided to retain the first 5 and second parts in the required adjusted position.

Desirably, a cover is provided for covering the open side of the saw body. Alternatively, the saw body may be constructed without an open side. Any hole in the cover and/or the saw body may be sealed by a removeable seal.

The adjustable shoe cum shroud may conveniently include a depth adjustment unit for attachment to the second part, the depth adjustment unit having a third slot or other aperture for the blade of the saw to penetrate.

According to another aspect of the present invention there is provided a guide system for use with the adjustable shoe cum shroud described above is comprising:

a pair of substantially parallel runners for receiving therebetween the second part of the adjustable shoe cum shroud, the runners being supported at opposite ends by support means which are at least as thick as the material to be cut with the saw; material alignment means against which the material to be cut is butted and which has a slot for receiving at least part of the blade of the saw after the material has been cut; sliding means for seating the second part and engagable with the runners; a base on which the support means and the material alignment means are mounted, the base having a slot which is disposed between the runners substantially parallel thereto for receiving blade of the saw; means for covering the slot in the material alignment means; and a slot insert member for removeable attachment to the adjustable shoe cum shroud and which is slidable in the slot.

The means for covering the slot may comprise an infill piece which fits between the runners and is moveable in a direction substantially parallel to the runners. It may be removeably attached to the adjustable shoe cum shroud.

Conveniently, the material alignment means is rotatable about a pivot whereby material can be cut at an angle to the runners. Also, it may be convenient to provide depth adjustment means for adjusting the height of the support means substantially to match the thickness of the material to be cut.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings, in which:- Fig. 1 is an exploded isometric view of a first or inner body part and a second or outer body part of an adjustable shoe cum shroud according to one embodiment of the invention for attachment to a hand-held circular saw; Fig. 2 is a side view of a circular saw and the inner body part of Fig. 1, the saw being slightly tilted back to give a view of its underside, and the inner body part being slightly tilted forward to show its upper face; Fig. 3 is an isometric view of a circular saw with the adjustable shoe cum shroud attached; Figs. 4, 5 and 6 are isometric views of alternative hollow wedges for use with the adjustable shoe cum shroud; Fig. 7 is an isometric view of a depth adjustment plate for attachment to the adjustable shoe cum shroud; Fig. 8 is a sectional view of a circular saw fitted with the adjustable shoe cum shroud and the depth adjustment plate; Fig. 9 is a sectional view of a circular saw fitted with the adjustable shoe cum shroud including a hollow wedge; Fig. 10 is an isometric view of a table top system for use with the adjustable shoe cum shroud; Fig. 11 is an exploded isometric view of Fig. 10, additionally showing thickness plates; Figs. 12 and 13 are sectional views taken along lines 12-12 and 13-13 6 of Fig. 10, showing a circular saw with the adjustable shoe cum shroud attached before and after a piece of material is cut; and Fig. 14 is a sectional view taken along line 14-14 of Fig. 12, showing the adjustable shoe. cum shroud having an inserted wedge.

Referring to Fig. 1, an adjustable shoe cum shroud 10, which is used in place of the conventional guide shoe or base plate, has a first or inner body part 20 and a second or outer body part 30. The inner body part is rectangular in shape and has a slot 40 for the saw blade of the circular saw to penetrate. The slot is positioned close to a long side 50 of the inner body part. The section of the inner body part between the slot and the opposite side has a recess 60 for receiving the underside of the saw body. The edge of the outer body part 30, alongside the recess 60, also has a matching recess 70. At opposite ends of the slot 40 are screws 80. The outer body part also has a saw slot 90 which is wider than the slot 40. The inner body part sits within the outer body part and is connected to the outer body part by a pair of hinges 100 attached at opposite ends of the length of the inner body part.

The saw slots 40,90 are aligned along coincident sides 130 where the hinges pivot about an axis 120 at this side. The coincident side of the slot 40 is the side of the slot closest to the long side 50. Between the hinges, the long side 50 of the inner body part is bevelled to enable the inner body part 20 to tilt to about 500 relative to the outer body part 30. The inner body part 20 has a flange 140 (see Figs. 8 and 9) on its underside and extending along the side of the slot 40 remote from the long side 50. This flange fits into the wider slot 90 when the inner body part sits within the outer body part and is not tilted.

The inner and outer body parts 20,30 may be made, for example, from compound board, hardboard, plywood, moulded plastics or pressed steel alloys.

Referring to Fig. 2, an electrically powered, hand-held circular saw 200 is lowered onto the adjustable shoe cum shroud 10 (of which only the inner 7 body part 20 is shown). Brackets 210 are fitted to opposite ends of the main body or casing 220 of the saw and these fit over the screws 80 protruding from the inner body part. The underside of the saw body 220 is received into the recess 60 in the inner body part and part of the saw blade 230 penetrates the slots 40,90 of the inner and outer body parts. The saw is secured to the adjustable shoe cum shroud by screwing nuts 85 onto the screws 80. The saw has a dust extraction socket 240 to which a vacuum cleaner may be connected to remove saw dust caused by cutting.

One side of the saw body 220 has an opening to enable the saw blade 230 to be easily changed. A cover plate 250 is attached to the saw body by, for example, adhesive, to prevent saw dust being sprayed into the ambient environment via this opening. The cover plate has a curved slot 260 through which part of a handle 270 attached to the blade guard 280 (a fragment of which is shown in Fig. 2) protrudes. This enables the blade guard to be retracted into the saw body 220 when sawing starts, and the blade guard seals the curved slot 260 when fully retracted. The slot 40 of the inner body part 20 is sufficiently wide to enable the blade guard to move freely between its open and closed positions. The cover plate 250 also has a hole 290 for receiving a hexagon key which is used to facilitate the removal and the replacement of the saw blade. The saw body 220 has a hole 300 which allows a kerf guide 310 of the saw to be adjusted. Both these holes may be sealed by plugs (not shown) which can be simply removed when needed. The plugs may be of rubber, plastic, nylon or any other suitable material.

Referring to Figs. 3 and 4, the saw 200 is shown attached to the inner body part 20 which is tilted at an angle relative to the outer body part 30.

The slot 90 in the outer body part -.is sufficiently wide to allow the saw blade 230 to penetrate for the whole range of tilt of the inner body part relative to the outer body part. A hollow wedge'320a is inserted between the hinged body parts of the adjustable shoe cum shroud, the wedge surrounding the slots 40,90 in the inner and outer body parts. There is a small knob or handle 8 350 on the back of the wedge 320a to assist insertion or removal of the wedge. Lugs 330 protruding from the outer body part 30 hold the wedge 320a in place. Recesses 340 are provided in the underside of the inner body part 20 to receive the lugs when the inner body part is not tilted relative to the outer body part. The base of the wedge has an extension 360 which abuts against the lugs 330 once the wedge is in place. This allows the wedge to be smaller than would be the case if the whole wedge extended to the lugs.

Adjustable angle clamping brackets 370 (only one of which is shown in an exploded position) are fitted to opposite ends of the inner body part 20 and the outer body part 30. The brackets are clamped at a required angle to retain the wedge 320a between the inner and outer body parts. The wedge allows a specific angle to be cut by a saw mounted on the adjustable shoe cum shroud 10, such as 450 required for mitred cutting.

An alternative wedge-like shroud 320b is shown in Fig. 5 where the is wedge is divided into two smaller hollow wedges 322,324 which can be used on their own or stacked. These wedges have interlocking lugs and recesses (not shown) which hold the wedges together. Recesses would additionally be provided in either the inner body part or the outer body part to receive the lugs of a single one of these two wedges 322,324. The two wedges may be angled at 150 and 300 respectively. Using these wedges on their own or in combination positioning the saw 200 to cut at angles to the vertical of 150, 300 or 450. A knob 350 is provided on the back of each wedge 322,324 to assist their insertion or removal.

An alternative hollow wedge 320c is shown in Fig. 6 which comprises a rigid top part 375, a rigid bottom part 380 and an intermediate part formed from a suitable resilient material, such as, foam latex rubber. The resilient intermediate part 390 enables the wedge to provide a range of angles from approximately 150 to above 500. The wedge is inserted between the inner body part 20 and the outer body part 30 and is compressed to a selected angle. The adjustable angle brackets 370 are then clamped to retain the 9 wedge at this angle. The wedge will always be at least slightly compressed once it has been positioned between the inner and the outer body parts, thus providing a more secure fit. Finger grips 400 extend from the bottom of the top part 375 and the top of the bottom part 380 to allow the wedge 320c to 5 be compressed when being inserted or removed.

The wedges 320a,320b of Figs. 4 and 5 and the top and bottom parts 375, 380 of Fig. 6 may be made, for example, from wood, plastics or metal.

Referring to Figs. 7 and 8, a depth adjustment plate or unit 410 is shown which may be attached to the underside of the adjustable shoe cum shroud 10. The plate 410 has a slot 420 for the saw blade 230 to penetrate.

One or more depth adjustment plates can be used in place of the wedgelike shroud when a saw 200 is being used to make a substantially vertical cut.

The plate or plates can give the saw blade 230 approximately the same depth of penetration "d" when cutting vertically as when cutting at an acute angle, as illustrated in Fig. 9. The depth adjustment plate 410 is hollow and has holes 422 for receiving screws 424 to screw the plate to the underside of the adjustable shoe cum shroud 10. A plurality of the depth adjustment plates may be positioned beneath the adjustable shoe cum shroud and be held in place by screws of increased length.

A user of a conventional hand-held electrically powered circular saw experiences a force caused by the leading part of the saw trying to tilt upwards. The use of the adjustable shoe cum shroud 10 gives the user a much more secure feeling by reducing the force caused by the leading part of the saw trying to tilt upwards. The use of at least one depth adjustment plate 410 further reduces this force.

Thus, when material is being cut with a hand-held circular saw 200 with the adjustable shoe cum shroud 10 attached, the part of the blade 230 above the material being cut is effectively contained within an enclosed area.

This part of the blade is enclosed by the inner body part 20 and the outer body part 30, the saw body 220, the cover plate 250 on the saw body, the hollow wedge 320, and the depth adjustment plate 410 or plates, if they are attached. The contoured recess 60 in the inner body part 20 which receives the saw body 220 ensures that there is substantially no gap between the inner body part and the saw body for saw dust to escape. As the saw teeth of the blade 230 rotate into the material being cut, saw dust is thrown into enclosed area where the saw dust is extracted by the vacuum cleaner attached to the dust extraction socket 240. However, it is estimated that about 5% of the saw dust produced falls below the material being cut, so that not all the saw dust is extracted.

To produce an environment where effectively 100% of the saw dust is extracted, the hand-held circular saw 200 and attached adjustable shoe cum shroud 10 may be used with a table top system 500, as shown in Figs. 10 and 11. The table top system has a base 510 which sits on and may be attached to a working surface. On the base 510 is a headboard 520 against which the material to be cut is butted. The headboard is shown partially cut away in Fig. 11 for clarity. It has a recess 530 and the bottom part of the headboard below the recess has a through hole 540. A rod 550, which protrudes from the base 510, passes through the hole 540 and allows the headboard to pivot about the rod. The headboard has a screw 560 which is screwed into a hole 570 in the base 510 to hold the headboard in place.

Twin track guide runners 580 are provided, which may be made from square aluminium tubing. First and second end spacers 590,600 are inserted into the opposite ends of the twin track runners. The first spacer 590 rests in the recess 530 of the headboard 520 and has a single hole 610 through which the rod 550 penetrates. The second spacer 600 has two holes 620 through which two other rods 630, extending from the base 510, penetrate when the second spacer is placed in position. Between the second spacer 600 and the base 510 is a plate 640 with two holes 620 through which the rods 630 extend. The plate 640 is the same thickness as the thickness of the bottom part of the headboard 520 below the recess 530.

In the base 510 and between the runners 580 is a slot 650 which extends for substantially the length of the runners and parallel to the runners.

The slot 650 is of dovetail shape in cross-section (see Fig. 14) with its widest part being at the bottom of the slot. The slot is sufficiently deep to receive the part of the blade 230 which penetrates the material to be cut and is wide enough to accept the blade for the range of tilt of the inner body part 20 of the adjustable shoe cum shroud 10 relative to the outer body part 30. The headboard 520 also has a slot 660 in its recess 530 which aligns with this slot 650. A slot insert piece 670 sits within the slot and is of dovetail shape in cross-section in order snugly to fit the slot 650 (see Fig. 14). The upper surface of the main part 672 of the insert piece is flush with the upper face of the base 510. The piece has an upright 674 at one end which extends well beyond the slot 650.

A saw seat slide board 680 is placed beneath the runners 580 and has a pair of opposite raised ends 682 which abuts against the outer sides of the runners 580. At the rear of the slide board is a raised end 684 which slides between the inner sides of the runners. The slide board has a slot 686 which extends to the leading edge of the board, the slot 686 aligning with the slot 650 in the base 510.

Between the twin track guide runners 580 is an infill piece 690 which hangs from a beam 692 supported by and slidable along the runners. Stops 694 are placed on the part of the runners under which the material to be cut is placed. The beam 692 and infill piece 690 are placed between the stops and the first spacer end piece 590.

Referring to Fig. 12, a piece of material 700 to be cut is first placed against the headboard 520 and the twin track guide runners 580 are placed above the material. Both the thickness of the bottom part of the headboard below the recess 530 and the plate 640 substantially match the thickness of the material to be cut. The slide board 680 is placed against and behind the material with the upright 674 of the slot insert piece 670 being placed in the 12 slot 686 of the slide board and against the rear raised end 684 of the slide board. The saw 200 with the attached adjustable shoe cum shroud 10 is placed so that the underside of the outer body part 30 sits on the slide board 680 with the outer body part snugly fitting between the runners. The rear of the adjustable shoe cum shroud 10 is attached to the upright 674 of the slot insert piece by contact magnets or other suitable means. Thus, the rear of the adjustable shoe cum shroud is placed close to the raised end 684 and this prevents the saw blade 230 from jarring at the beginning of the cutting operation. It is preferable that the slot 686 of the slide board initially extends beyond the blade by at least 2 cm. The infill piece 690 is placed so that the beam 692 is against the stoppers 694 with the infill piece covering the slot 660 in the headboard 520.

A vacuum cleaner, attached to the dust extraction socket 240 of the saw 200, is switched on and the saw and the adjustable shoe cum shroud 10 are pushed forward by the user so that the blade 230 cuts the material 700.

The slot insert piece 670 effectively closes the air gap in the slot 686 in the slide board 680 and the slot 650 in the base 510, preventing saw dust escaping and creating a more powerful vacuum for dust extraction. Before the blade has finished cutting through the material, the front of the adjustable shoe cum shroud 10 starts to push the infill piece 690. Contact magnets or other suitable means may be used to connect the infill piece to the front of the adjustable shoe cum shroud.

Referring to Fig. 13, the saw 200 is advanced until the leading edge of the blade 230 is within the slot 660 in the headboard 520 and the infill piece 690 is abutting against the first spacer end piece 590. Thus, the infill piece and the adjustable shoe cum shroud 10 prevent saw dust from escaping via the slot 660 and the part of the slot 650 in front of the blade. The slot insert piece 670 is detached from the rear of the adjustable shoe cum shroud when the upright 674 comes into contact with the material 700 being cut.

After the material 700 has been cut, the saw 200 and adjustable shoe 13 cum shroud 10 are pulled back. The attached infill piece 690 is also pulled back until the beam 692 makes contact with the lugs 694 on the runners 580, thereby causing the infill piece to become detached from the front of the adjustable shoe cum shroud.

If the material being cut is thicker than both the bottom part of the headboard 520 below the recess 530 and the plate 640,then thickness plates 710,720 are placed between the spacers 590,600 and the headboard 520 and the plate 640 respectively, as shown in Fig. 11. These plates 710,720 have holes 610,620 for receiving the respective rods 550,630. Also, a thickness plate 725, shaped to suit the underside of the slide board 680, is attached to the underside of the slide board. A plurality of thickness plates 710,720,725 may be placed substantially to match the thickness of the material being cut.

As well as being able to cut the material perpendicularly to the runners 580, the material may be set at a preset angle relative to the runners by swivelling the headboard 520 about the rod 550 and screwing the screw 560 into one of the holes 570 in the base, as shown in Fig. 10, where each hole 570 is positioned for a preset angle. The recess 530 in the headboard and any thickness plates 710 have additional slots 730 to align with the base slot 650 when the headboard is set to a preset angle.

Whilst particular embodiments have been described, it will be understood that various modifications may be made without departing from the scope of the invention. For example, the lugs 330 protruding from the outer body part 30 may be replaced by a recess in the outer body part for receiving the hollow wedge 320 and a similar recess may also be provided in the underside of the inner body part 20. A larger sized wedge may be used, therefore removing the need for the lugs 330.

Instead of attaching the saw 200 to the adjustable shoe cum shroud 10 by brackets 210, screws 80 and nuts 85, alternative attachment means may be provided. The adjustable shoe cum shroud 10 may be provided with a 14 different shaped recess 60,70 to match the underside of the saw body or casing of a different make of hand-held circular saw. A thin plastic nylon strip, following the line of the curved slot 260 of the cover plate 260 of the saw 200 may be fixed onto the slot side of the blade guard 280, and onto the internal side of the cover plate on opposite sides of the slot 260.

The depth adjustment plate 410 may be solid. At least one plate 410 may be used at any angle of tilt of the saw blade 230, the slot 420 in the or each plate 410 being sufficiently wide to allow the saw blade to penetrate for the whole range of tilt. The depth adjustment plate may be connected to the adjustable shoe cum shroud 10 or to another depth adjustment plate by spring clips, for example, which clip opposite side edges of the depth adjustment plate 410 to the adjustable shoe cum shroud or to another depth adjustment plate. These clips could be staggered so as not to cause an obstruction to each other when a plurality of depth adjustment plates are used.

Alternatively, the depth adjustment plate may have wedge shaped protrusions, which are wider at their free ends, and which can be slid into suitably shaped recesses in the underside of the adjustable shoe cum shroud or another depth adjustment plate.

The shoe cum shroud may be supplied as a kit of parts for attachment to a hand-held circular saw, including, for example, the hinged inner and outerbody parts, the cover plate, and the hollow wedge or wedges. The cover plate, however, may instead be an integral part of the main body of the saw.

The adjustable shoe cum shroud may be an integral part of a hand-held circular saw. Where the adjustable shoe cum shroud has a compressible wedge, then this wedge may be an integral part of the shoe cum shroud.

Claims

CLAIMS:

1. An adjustable shoe cum shroud for attachment to a hand-held circular saw for reducing or minimising the discharge of saw dust into the ambient environment when cutting, comprising:

a first part adapted to be secured to the saw body in close proximity to and/or against the underside of the saw body, and a second part having an underside which is intended to be located on a surface to be cut, the first and second parts having first and second slots for the saw blade to penetrate, and the second part being pivoted to the first part about an axis disposed to one side of the first and second slots and substantially parallel to the slots and therefore to a saw blade when the adjustable shoe cum shroud is operably assembled to a circular saw; and shroud means for substantially closing the gap between the first and second parts when the first part is tilted relative to the second part.

2. An adjustable shoe cum shroud as claimed in claim 1, wherein the shroud means is configured to extend from the pivotable interconnection between the first and second parts and about the first and second slots.

3. An adjustable shoe cum shroud as claimed in claim 1 or 2, wherein the shroud means comprises at least one hollow wedge, whereby the degree of the angle of tilt of the first part relative to the second part is adjusted by varying the number of superimposed wedges used, and/or the wedge angle of the or each wedge.

4. An adjustable shoe cum shroud as claimed in claim 3, wherein the shroud means supports the first part when tilted relative to the second part.

5. An adjustable shoe cum shroud as claimed in any preceding claim, 16 wherein the shroud means comprises a resilient member for closing the gap between the first and second parts whilst accommodating a range of adjustable included angles between the first and second parts.

6. An adjustable shoe cum shroud as claimed in any preceding claim, including an adjustable angle clamping means for retaining the first part at the required angle of tilt relative to the second part.

7. An adjustable shoe cum shroud as claimed in any preceding claim, including a depth adjustment unit for attachment to the second part, the depth adjustment unit having a third slot or other aperture for the blade of the saw to penetrate.

8. A hand-held circular saw including an adjustable shoe cum shroud as claimed in any preceding claim.

9. A hand-held circular saw as claimed in claim 8, including a cover for covering an open side of the saw body.

10. A hand-held circular saw as claimed in claim 8 or 9, including a removeable seal for sealing a hole in the saw body or in the cover.

11. A guide system for use with the adjustable shoe cum shroud as claimed in any preceding claim, comprising:

a pair of substantially parallel runners for guiding the adjustable shoe cum shroud, the runners being supported at opposite ends by support means which are at least as thick as the material to be cut with the saw; material alignment means against which the material to be cut is butted; and a base on which the support means and the material alignment means 17 are mounted.

12. A guide system as claimed in claim 11, wherein the pair of substantially parallel runners is adapted to receive therebetween the base of the adjustable 5 shoe cum shroud.

13. A guide system as claimed in claim 11 or 12, including sliding means for receiving at least part of the base of the adjustable shoe cum shroud.

14. A guide system as claimed in claim 13, wherein the sliding means is engagable with the runners.

15. A guide system as claimed in any one of claims 11 to 14, wherein the guide system base has a slot which is disposed between the runners and substantially parallel thereto for receiving the blade of the saw.

16. A guide system as claimed in claim 15, including a slot insert member for attachment to the adjustable shoe cum shroud and which is slidable in the slot.

17. A guide system as claimed in claim 16, wherein slot insert member is adapted to be removeably attached to the adjustable shoe cum shroud.

18. A guide system as claimed in any one of claims 11 to 17, wherein the material alignment means has a slot for receiving at least part of the blade of the saw after the material has been cut.

19. A guide system as claimed in claim 18, including means for covering the slot in the material alignment means.

18

20. A guide system as claimed in claim 19, wherein the means for covering the slot comprises an infill piece which fits between the runners and is moveable in a direction substantially parallel to the runners.

21. A guide system as claimed in claim 20, wherein the infill piece is removeably attached to the adjustable shoe cum shroud.

22. A guide system as claimed in any one of claims 11 to 21, wherein the material alignment means is rotatable about a pivot.

23. A guide system as claimed in any one of claims 11 to 22, including depth adjustment means for adjusting the height of the support means substantially to match the thickness of the material to be cut.

24. An adjustable shoe cum shroud constructed substantially as hereinbefore described with reference to the accompanying drawings.

25. A guide system for use with an adjustable shoe cum shroud constructed substantially as hereinbefore described with reference to the 20 accompanying drawings.

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