GB2061184A - Dust extraction in saw tables - Google Patents

Abstract

A saw table 10 having a pair of parallel elongate hollow elements 16, 17, one above the other, having opposed longitudinal slots 22, 23 capable of receiving the blade of a circular saw 25 which can traverse the slots to cut a workpiece. Dust is collected within the hollow elements 16, 17 and removed by suction. Various cutting modes are described to cut the different faces of a workpiece. <IMAGE>

Description

SPECIFICATION Improvements in or relating to saw tables This invention relates to saw tables, and has particu larapplication to a saw table on which a movable saw can be mounted to traverse a workpiece support surface, e.g. for the cutting of sheets of material.

It is an object of this invention to provide an improved saw table capable of utilizing a movable saw, and including means for extracting and collecting dust resulting from the sawing operation.

In one aspect, the invention provides a saw table including a pair of elongate hollow elements mounted substantially parallel to one another, each hollow element having a longitudinal slot through a wall thereof, capable of receiving a saw blade therein, one of said hollow elements forming a section of a workpiece support; support and guide means for a saw to enable the blade of a saw to travel within said slots; and air extraction means coupled to the interior of each of the hollow elements.

In another aspect, the invention provides a saw table, including a pair of elongate hollow elements mounted substantially parallel to one another, a first one of said hollow elements having a longitudinal slot through a wall thereof, and forming a section of a workpiece support, a second hollow element having a pair of opposed slots therethrough, an inner one of said slots of said second element facing towards the slot of said first element, sealing means being provided in association with the outer slot of said second element; a saw blade passing through said slots of said second element and protruding into the slot of the first element; a cover over said saw blade, said blade and cover capable of moving along the outer slot of the second element; means for sealing said cover against said second element; and air extraction mseans coupled to the interior of each hollow element.

Other aspects of this invention, which should be considered in all its novel aspects, will become apparent from the following description, which is given by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a preferred saw table in accordance with this invention.

Figure 2 illustrates a cross-section through the saw and hollow elements of Figure 1.

Figure 3 illustrates an alternative embodiment in which the saw blade passes through the upper hollow element: Figures 4to 6 illustrates various cutting operations utilizing the apparatus of Figure 1.

A saw table 10 has a frame 11 and a workpiece supporting surface 12. Conveniently, the frame 10 is formed of box section steel and any suitable workpiece supporting surface 12 may be provided thereon.

It will be generally convenient to provide a workpiece supporting surface 12 having outriggers 13 capable of supporting a large sheet of material. A fence or stop 14 may be provided on the table to regulate the position of a sheet of material to be cut by the saw table.

The saw table has a slot 15 extending through the workpiece supporting surface 12.

Afirst hollow element 16 is provided beneath the workpiece supporting surface to provide the slot 15.

In addition, the second hollow element 17 is positioned substantially parallel to the first hollow element, and spaced apart from the workpiece supporting surface.

These hollow elements are preferably formed of tubes of box section, and are connected together by a manifold 18 at one end thereof. The other ends of the hollow elements can be connected to a conduit or conduits 19 which is in turn connected to air extraction means (not shown). The air extraction means conveniently consists of a suction pump together with a dust collection container or bag at the outlet thereof to collect sawdust whilst the saw table is in operation.

Means is provided to control the direction of suction and air flow applied to the hollow elements.

The ends of the hollow elements can be provided with suitable valves to enable them to be switched between an air inlet mode and a suction mode.

Clamps 20, 21 may be provided to clamp the workpiece in place. Conveniently, these clamps are hydraulically or pneumatically operated piston and cylinder arrangements capable of securely holding a workpiece against the surface 12.

Each hollow element is provided with a longitudin al slot through a wall thereof with slot 22 being provided in the first or lower element 16, and slot 23 being provided in the second or upper element. The lower slot 22 coincides wth the slot 15 in the surface 12. The upper slot 23 is provided with sealing means 24 in the form of a pair of resilient lips, which close off the slot when not in use.

Slots 22 and 23 face one another, and are each capable of receiving a sawblade 25 therein. As illustrated, there is a circular sawblade 25 positioned between the upper and lower elements, with the edges of the blade, in use, protruding into both the lower and upper slots. The blade 25, may be provided with a suitable saw guard 26 in the form of a casing surrounding the blade. This casing is preferably adapted to fit within the confines of slot 23. The upper portion of the saw guard can be provided with spreading means at each end thereof to spread the resilient lips as the saw guard moves along the slot 23. The spreading means which may be provided by the ends of the saw guard serves to spread the resilient lips and keep them away from the sawblade as the sawblade travels along the slot.

The circular sawblade 25 can be coupled to a suitable motor. It may take the form of a portable circular saw, or it may be provided with a separate motor 27, as shown, and a coupling 28 between the motor and the shaft 29 of the blade. A guide track (not shown) is provided alongside the upper hollow element 17. This is preferably in theform of a separate gantry adjacent to and parallel to the upper hollow element.

Preferably, means for moving the sawblade along the longitudinal slots 22,23, is provided. This may take the form of hydraulically or pneumatically operated piston and cylinder device, or for example, may take the form of cables attached to the saw and driven by a reversible winch. In addition, the saw blade is preferably movable vertically with respect to the hollow elements. The movement of the sawblade will be described with reference to Figures 4 to 6. The movement of the sawblade can be controlled by a suitable control means 30, and if desired, this can contain a programme to control the various motions of the saw for different cutting operations.

Figure 4 illustrates the down cutting mode where a workpiece 31 is cut from above. In this arrangement, the upper hollow element 17 is provided with a resilient seal as is illustrated in Figure 2, whilst the slot 22 in the lower element is covered by workpiece 31. The lower element 16 is connected to suction means, whilst the upper element 17 is connected to the atmosphere to allow airto enter the end of the upper element 17. Air will thus flow through the upper element 17 around the manifold and back through the lower element 16. A certain amount of air will enter the upper element 17 in the vicinity of the saw guard, whilst some air will enter the lower element 16 through the lower slot 22 where this is uncovered and where the saw cuts through the workpiece.

The cutting operation proceeds from right to left to Figure 4. With the sawblade in a resting position at point'A', on command, the blade will descend from its guard moving to point 'B' where it protrudes into the lower slot 22. The spacing between the upper and lower hollowed out elements is such that the sawblade will be partially within both slots in position 'B'. The cutting stroke will then commence, and the sawblade will move from position 'B' to position 'C', with the saw rotating counter clockwise to thus cut the workpiece from above. At the end of the cutting stroke, the saw will then be returned to its saw guard at position 'D' then return to position 'A'.

Figure 5 illustrates an upcutting mode where it is desired to cut the material from below. In this arrangement the saw rests at position 'A', and in the cutting mode descends to position 'B' and cuts from left to right until it reaches position 'C'. It can then be retracted into the guard at position 'D' and return to position 'A'. In this arrangement, it is preferred that the suction is applied to the upper tube 17, with air admitted to the lower tube.

Figure 6 illustrates an arrangement in which a workpiece is scored on one surface prior to cutting.

This is desirable where a workpiece such as a board is faced on both sides, e.g. with formica or the like.

The scoring stroke takes place from right to left, whilst the cutting stroke takes place from left to right.

On command, the saw remains in its guard, but moves from position 'A' to position 'D'. It then descends to 'E' and over scores the panel through to position 'F'. During this scoring stroke, the blade is cutting down into the workpiece to score the upper surface thereof. The blade then is lowered from position 'F' to position 'B' and cuts through the work from left to right until it reaches position 'C'.

From 'B' to 'C', it operates in an upcutting mode and thus cuts through the reverse face of the board providing a clean cut. The blade is then retracted into its guard and awaits a further scoring cut, or it can be returned to position 'A' to await a normal cutting cycle.

It will be appreciated that various cutting cycles can be programmed given the movement of the sawblade up and down with respect to the hollow elements, and also movement along the length of the hollow element.

Figure 3 illustrates an alternative embodiment, in which the upper hollow element can also function as a workpiece clamp. This hollow element 33 preferably has a pair of conjoined members 34,35, having a split line there between. This defines an upper slot 37, and a lower slot or open face 38. The edges of these members 34, 35, are preferably provided with a resilient material to seal against a workpiece, or the workpiece supporting surface. In addition, a resilient seal 40 is provided in the upper slot 37 in a similar fashion to the resilient lips described in Figure 2. A sawblade 41 is positioned so as to pass through the upper hollow element 33 and to protrude into the slot of a lower hollow element (not shown).

The sawblade 41 is provided with a cover 42 to enclose the blade and this cover 42 is preferably sealed against the upper surface of the hollow element 33. It can also be provided with spreaders at either end thereof to open up the resilient seal 40 as the cover and sawblade moves along the upper hollow element.

By this means, the sawblade can traverse the workpiece, whilst the workpiece is clamped in place by the upper hollow element 33. Suction can be applied to the upper and lower hollow elements in a similar fashion to that described with reference to the saw table of Figures 1 and 2.

Various types of seals can be provided on the slots, although it has been found that the lower slot need not be sealed, as it is covered for the most part by the workpiece.

In use, it has been found that dust and other particles resulting from the sawing operation-can be collected within the hollow elements and extracted and collected by the suction means.

It will be generally convenient to use the saw table of this invention with the workpiece supporting surface horizontal. However, the invention can be utilized in other arrangements with the workpiece supporting surface inclined, if desired.

Finally, it will be appreciated that various other alterations and modifications may be made to the foregoing without departing from the scope of this invention as exemplified in the following claims.

Claims (11)

1. A saw table including a pair of elongate hollow elements mounted substantially parallel to one another, each hollow element having a longitudinal slot through a wall thereof, capable of receiving a saw blade therein, one of the said hollow elements forming a section of a workpiece support; support and guide means for a saw to enable the blade of a saw to travel within said slots; and air extraction means coupled to the interior of each of the hollow elements.

2. A saw table as claimed in claim 1, and further including a circular saw having its blade mounted in line with said slots.

3. A table saw as claimed in claim 2, wherein said circular saw is capable of vertical movement with respect to said slots.

4. A saw table as claimed in claim 3, and further including sealing means associated with either or both slots to at least partially close off said slots.

5. A saw table as claimed in claim 4, wherein a guard is provided about said saw blade.

6. A saw table as claimed in claim 5, wherein said sealing means consists of a pair of resilient lips attached to and closing off one of said slots.

7. A saw table as claimed in claim 6, and further including spreading means mounted at each end of said guard to open said resilient lips as said guard is moved along said slot.

8. A saw table as claimed in claim 7 wherein said hollow elements are connected together at one end by a manifold.

9. A saw table as claimed in claim 8 and further including means for reversing the direction of suction applied to said hollow elements.

10. A saw table including a pair of elongate hollow elements mounted substantially parallel to one another, a first one of said hollow elements having a longitudinal slot through a wall thereof, and forming a section of a workpiece support, a second hollow element having a pair of opposed slots therethrough, an inner one of said slots of said second element facing towards the slot of said first element, sealing means being provided in association with the outer slot of said second element; a saw blade passing through said slots of said second element and protruding into the slot of the first element; a cover over said saw blade, said blade and cover capable of moving along the outer slot of the second element; means for sealing said cover against the second element, and air extraction means coupled to the interior of each hollow element.

11. A saw table substantially as herein described with reference to Figures 1 and 2, or Figure 3, or Figure 4, or Figure 5, or Figure 6, of the accompanying drawings.