GB2240262A

GB2240262A - Apparatus for dust extraction

Info

Publication number: GB2240262A
Application number: GB9001841A
Authority: GB
Inventors: Mark Dudley Haydon; John Russell; Brian Angus Bateson
Original assignee: NIMBUS DIAMOND TOOL AND MACHIN
Current assignee: NIMBUS DIAMOND TOOL AND MACHIN
Priority date: 1990-01-26
Filing date: 1990-01-26
Publication date: 1991-07-31
Also published as: GB9001841D0

Abstract

Apparatus for dust extraction, particularly for use when drilling holes in walls, comprises a member 2 having an outer part adapted to be applied to the surface around the hole to be drilled, an inner circular aperture through which the drill 28 is adapted to pass, and a duct 12 for connecting the member to a source of air suction so that dust-laden air is extracted from the member during drilling. As shown, a hose 14 of a standard vacuum cleaner is attached directly or through a baffled filter, Fig 3 (not shown) to a connector 12 which is provided with a chamber (26) Fig 2 (not shown) and seals (22, 24) to suction-hold the member to the wall while extracting dust from inside a shroud 6. Various sized adaptor caps 8 may be provided. <IMAGE>

Description

Title: Apparatus for dust extraction Field of the invention This invention relates to apparatus for dust extraction, and in particular to dust extraction apparatus for use in drilling holes in walls.

Background to the invention When drilling holes in internal walls the problem is frequently encountered that an unacceptable quantity of dust is created. This problem is of course exacerbated if a large hole has to be drilled in an internal brick wall, particularly in a newly decorated, furnished living room.

Such a large hole may be needed, for example, for an air vent for a gas fire, or alternatively for a ventilation hole for a tumble dryer.

It is an object of the present invention to provide apparatus which at least reduces the above problem.

Summary of the invention According to one aspect of the present invention there is provided apparatus for dust extraction, particularly for drilling holes in walls or the like, comprising d member having an outer part adapted to be applied to the surface around the hole to be drilled, an inner circular aperture through which the drill is adapted to pass, and duct means for connecting the member to a source of air suction so that dust-laden air is extracted from the member during drilling.

The outer part of the member preferably includes a flat annular portion incorporating a seal around its periphery, the annular position being in communication with the duct.

Advantageously second seal is provided at the inner periphery of the annular portion, thereby forming with the wall or the like an annular suction chamber to enable the member to be held to the wall by suction.

The member may further include a generally cylindrical shroud in communication with the duct. The shroud may be frusto-conical, tapering outwardly away from said aperture by an included angle of about 40.

Advantageously the shroud includes a removable cap incorporating the circular aperture, whereby caps of different aperture sizes may be provided to accommodate a range of drill diameters.

The duct means preferably comprises a tee-connection communicating both with the annular portion and the shroud. Advantageously the outlet of the tee-connection is of a size such that it may be connected to a standard hose of a domestic vacuum cleaner.

Mounted in a duct between the member and the source of suction there may be a pre-filter for filtering out some of the dust from the air flow. Thus where a vacuum cleaner is used as a source of suction, its own filter is less likely to become clogged. The pre-filter may take the form of a series of air baffles for changing the direction of the dust-laden air flow, whereby dust is separated from the air flow at each such change of direction.

According to a second aspect of the invention, there is provided in combination with a vacuum cleaner a pre-filter for filtering dust-laden air as above defined.

Brief description of the drawings The invention will now be described, by way of example only, with reference to the accompanying drawings in which: Figure 1 is a perspective view of a dust extractor in accordance with the invention; Figure 2 is an exploded partial section of the extractor; and Figure 3 is a schematic section of a pre-filter for use with the extractor.

Detailed description of the drawings The extractor shown in Figures 1 and 2 consists of a generally hat-shaped member 2 comprising a flat annular rim 4 merging into a frusto-conical shroud 6 inclined by an angle of approximately 20 to the central axis of the member.

An adaptor cap 8 is arranged to seat over the shroud 6 and is provided with an inner rolled edge 10, thus forming a circular hole 11.

Both the member 2 and the cap 8 are made of thin lightweight aluminium by a spinning operation.

connected to the lower side of the member 2 is a teeshaped hose connector 12 to which the hose 14 of a standard domestic vacuum cleaner is adapted to be connected at the outlet end 16. The tee-connector 12 is preferably made of a plastics material and communicates via a hole 18 with the inside of the shroud 6, and similarly through a hole 20 with the other side of the rim 4. In practice the tee-connector may be secured to the member 2 by respective bushes or grommets (not shown) in the holes 18 and 20.

Secured to the outer periphery of the rim 4 is a foam sealing strip 22, and a similar sealing strip 24 is secured to the inner periphery of the rim, thereby forming with a wall W to be drilled an annular suction chamber 26.

In use, the dust extractor is placed over a marked position where a hole is to be drilled. With the teeconnector connected to a vacuum cleaner the latter is switched on, thereby creating suction in the chamber 26, enabling the lightweight extractor to be held by suction against the wall, the foam seals 22 and 24 maintaining the suction in the chamber 26. A large diamond tipped core drill, mounted on a power drill 30, may now be fed through the circular hole 11 in the cap 8 in order to commence drilling of the hole in the wall W.

As the inevitable dust forms, particularly during the initial part of the drilling operation, air is drawn through the hole 18, thereby sucking the dust-laden air downwards into the vacuum cleaner. The annular space formed between the drill 28 and the shroud 6 ensures that dust is extracted all around the drill, so that virtually no dust can escape past the edge 10 in the cap.

When the drilling operation has been completed, the drill is withdrawn, with the dust extractor still being held by suction to the wall. The operator may then hold the extractor, disconnecting the hose 14 and inserting it through the hole 11 to remove larger pieces of wall debris which may have collected inside the shroud 6.

Two or more different sizes of adaptor cap 8 may be provided for different diameters of core drills. For example, the internal diameter of the rolled edge 10 may typically be 170mm to cope with drills of 90-150mm in diameter, and a smaller adaptor cap with an internal diameter of lOOmm may be provided for smaller diameter drills.

Since a considerable amount of fine dust may be generated during drilling of a large hole, some domestic vacuum cleaners may have dust bags which would quickly become clogged up, possibly damaging the electric motor in the process.

Accordingly, in a modification of the apparatus, as shown in Figure 3, a pre-filter is provided upstream of the vacuum cleaner. The filter comprises a generally box-like chamber 32 having an inlet connected to the hose 14 and an outlet connected by a hose 34 to the vacuum cleaner (not shown). Mounted in the chamber are a large number of baffles 36, thereby creating an undulating or zig-zag path for the dust-laden air. Thus at each change of direction of the air flow the dust is subjected to centrifugal forces, causing the dust to be separated out against the baffles. When a given quantity of dust has been collected the chamber may be opened (by means not shown) to shake out the accumulated dust.

It will be appreciated that the dust extractor described above provides an elegant and inexpensive solution to the problem of containing and collecting the dust created during a drilling operation.

Claims

1. Appartus for dust extraction, particularly for drilling holes in walls or the like, comprising a member having an outer part adapted to be applied to the surface around the hole to be drilled, an inner circular aperture through which the drill is adapted to pass, and duct means for connecting the member to a source of ai; suction so as to extract dust-laden air from the member during drilling.

2. Apparatus according to claim 1 in which the outer part of the member includes a flat annular portion incorporating a seal around its periphery, the annular portion being in communication with the duct.

3. Apparatus according to claim 2 in which a second seal is provided at the inner periphery of the annular portion, thereby forming with the wall or the like an annular suction chamber to enable the member to be held to the wall by suction.

4. Apparatus according to any of the preceding claims in which the member further includes a generally cylindrical shroud in communication with the duct.

5. Apparatus according to claim 4 in which the shroud is frusto-conical.

6. Apparatus according to either claim 4 or claim 5 in which the shroud includes a removable cap incorporating the circular aperture, whereby the cap may be selected from a number of caps of different aperture sizes to accommodate a range of drill diameters.

7. Apparatus according to any of the preceding claims in which the duct means comprises a tee-connection communicating both with the annular portion and the shroud.

8. Apparatus according to claim 7 in which the outlet of the tee-connection is of a size such that it may be connected to a standard hose of a domestic vacuum cleaner.

9. Apparatus according to any of the preceding claims in which there is provided a pre filter, mounted in a duct between the member and the source of suction, for filtering out some of the dust from the air flow.

10. Apparatus according to claim 9 in which the prefilter takes the form of a series of air baffles for changing the direction of the dust-laden air flow, whereby dust is separated from the air flow at each such change of direction.

11. A vacuum cleaner having a pre-filter of the kind defined in claim 9 or claim 10.

12. Apparatus substantially as described herein with reference to, and as illustrated in, the accompanying drawings.

13. A pre-filter substantially as described herein with reference to, and as illustrated in, figure 3 of the accompanying drawings.