GB2235480A

GB2235480A - Improvements in or relating to the clearing of drills

Info

Publication number: GB2235480A
Application number: GB8918558A
Authority: GB
Inventors: Malcolm Pickard Eastburn
Original assignee: English Drilling Equipment Co Ltd
Current assignee: English Drilling Equipment Co Ltd
Priority date: 1989-08-15
Filing date: 1989-08-15
Publication date: 1991-03-06
Also published as: GB8918558D0

Abstract

To clear an auger (10) the auger is moved in an upwards direction and rotated in a clockwise direction. The teeth 28 on a wheel 16 lie between adjacent parts of the auger blade 30 and the wheel 16 rotates in an anticlockwise direction such that successive teeth lie between different portions of adjacent blades in order that any material located between the blades comes into contact with the side of at least one tooth and is pushed or swept clear of the auger. The toothed wheel can be pivoted out of the position shown about a vertical axis such that the teeth 28 are clear of the auger 10. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO THE CLEARING OF DRILLS.

The present invention relates to a drill clearing device and to a method of clearing a drill and is particularly, although not exclusively, applicable to such devices for and methods of clearing augers.

When an auger drill is raised out of the ground after a hole has been drilled, the spaces between the blades of the auger may contain heavy lumps of earth or clay which, if they are allowed to rise several metres above the ground and are then permitted to fall off create a hazard to operators. As larger diameter augers and longer augers are used the problem increases as the weight of the earth or clay and the height from which it may fall increases.

According to one aspect of the present invention a drill clearing device includes a clearing portion movable between a first position in which the clearing portion is arranged to be located between adjacent portions of a flute of a drill and a second position in which the clearing portion is arranged to be spaced from adjacent portions of a flute of a drill.

The clearing portion may be pivotally movable between the first and second portions.

The clearing portion may be arranged to be located in the region of the ground into which an auger drill is arranged to be inserted.

The clearing portion may be comprised by a plurality of clearing members in which, when the first portion is in the first position, at least one of the clearing members may be arranged to be in the first position with successive clearing members being brought into the first position. The plurality of clearing members may be provided on the periphery of a pivotally mounted member. The pivotal axis of the pivotally mounted member at its region nearest to the clearing members may be arranged to be generally equidistant from each clearing member. A drive may be provided for the clearing members with the drive being arranged to assist in or cause successive members to be brought into the first position. The drive may comprise a slip drive.

In the first position the clearing portion or members may be arranged to present a negative rake angle with respect to the intended direction of rotation of the drill.

The clearing portion or members, when in the first position, may be arranged to abut a surface of a drill which faces away from the intended axis of rotation of the drill.

The present invention also includes a clearing device when mounted adjacent to a drill such that the device is able to be moved between the first and second positions.

According to another aspect of the present invention a method of clearing a drill comprises moving a clearing device into a first position in which the clearing portion is located between adjacent portions of a flute of a drill and rotating the drill and causing translational movement of the drill in order that the region between the adjacent flutes of the drill can be at least partially cleared by the clearing device.

The method may comprise moving the clearing portion to the first position from a second position in which the clearing portion is spaced from the region between adjacent flutes of the drill.

The method may comprise moving successive clearing members of the clearing portion into the first position when clearing the drill, and the method may comprise pivoting the clearing members such that successive members are brought into the first position.

The method may comprise driving the clearing members such that successive members are brought into the first position, and the method may comprise driving the members with a slip drive.

The method may comprise presenting a negative rake angle to the shaft of the drill when the clearing portion or clearing members are in the first position.

The method may comprise the clearing portion or the clearing members abuting the shaft of the drill when in the first position.

The present invention may be carried into practice in various ways but one embodiment will now be described by way of example and with reference to the accompanying drawing which is a schematic side view of a continuous flight auger 10 and a clearing device 12.

The clearing device 12 comprises a fixed mounting 14 to which a clearing toothed wheel 16 is connected by a pair of mounting arms 18. The arms 18 are connected to the wheel via a rotational bearing 20, and the arms 18 are also pivotally connected to the fixed mounting 14 at two spaced locations 22 about a vertical axis 24. A locking device 26, shown schematically in the drawings, can be selectively applied in order to retain the toothed wheel in the position shown.

In operation, when the auger is being cleared, and with the toothed wheel locked in the position shown, the auger is moved in an upwards direction and rotated in a clockwise direction. The pitch of the teeth 28 on the wheel 16 is such that each tooth, as it extends within the area being swept by the auger 10 lies between adjacent parts of the auger blade 30. The wheel 16 rotates in an anti-clockwise direction such that successive teeth lie between different portions of the adjacent blades in order that any material located between the blades comes into contact with the side of at least one tooth and is pushed or swept clear of the auger. If desired the periphery of the teeth may come into sliding engagement with the shaft 32 of the auger on which the blades are mounted.In a further embodiment the leading edge of each tooth may include a negative rake with respect to the direction of rotation of the auger in order to assist in the outwards deflection of material abuting the teeth.

In a modification (not shown) the tooth wheel may be driven in its rotational direction by an external drive, rather than being driven by the upwards and rotational movement of the auger. Where a separate drive is provided for the wheel, that drive may be a slip drive, and this separate drive decreases or negates the upwards force exerted by the blades of the auger on the teeth of the wheel.

When the auger has been cleared, and it is no longer desired to have the toothed wheel in the cleaning or clearing position, the locking device 26 is released and the toothed wheel is pivoted about the vertical axis 24 in a clockwise direction until the teeth of the wheel lie clear of the auger. In that position the auger can be used to drill a further hole and, in a typical application, after the hole has been completed, concrete can be laid in the hole through a conduit extending through the centre of the shaft 32 whilst the auger shaft is rotated slowly in the clockwise direction and simultaneously raised. Whilst the concrete is being applied to the hole the clearing device can be moved back and locked into the position shown in the drawing to clear the auger.

Claims

1. A drill clearing device including a clearing portion movable between a first position in which the clearing portion is arranged to be located between adjacent portions of a flute of a drill and a second position in which the clearing portion is arranged to be spaced from adjacent portions of a flute of a drill.

2. A device as claimed in Claim 1 in which the clearing portion is pivotally movable between the first and second positions.

3. A device as claimed in Claim 1 or 2 in which the clearing portion is arranged to be located in the region of the ground into which an auger drill is arranged to be inserted.

4. A device as claimed in any preceding claim in which the clearing portion is comprised by a plurality of clearing members in which, when the first portion is in the first position, at least one of the clearing members is arranged to be in the first position with successive clearing members being brought into the first position.

5. A device as claimed in Claim 4 in which the plurality of clearing members are provided on the periphery of a pivotally mounted member.

6. A device as claimed in Claim 5 in which the pivotal axis of the pivotally mounted member at its region nearest to the clearing members is arranged to be generally equidistant from each clearing member.

7. A device as claimed in any of Claims 4 to 6 in which the drive is provided for the clearing members with the drive being arranged to assist in, or cause successive members to be brought into the first position.

8. A device as claimed in Claim 7 in which the drive comprises a slip drive.

9. A device as claimed in any preceding claim in which, in the first position, the clearing portion or members are arranged to present a negative rake angle with respect to the intended direction of rotation of the drill.

10. A device as claimed in any preceding claim in which the clearing portion or members, when in a first position, are arranged to abut a surface of a drill which faces away from the intended axis of rotation of the drill.

11. A drill including a clearing device as claimed in any preceding claim when mounted adjacent to the drill such that the device is able to be moved between the first and second positions.

12. A drill clearing device substantially as herein described with reference to, and as shown in the accompanying drawing.

13. A method of clearing a drill comprising moving a clearing device into a first position in which the clearing portion is located between adjacent portions of a flute of a drill and rotating the drill and causing translational movement of the drill in order that the region between the adjacent flutes of the drill can be at least partially cleared by the clearing device.

14. A method as claimed in Claim 13 comprising moving the clearing portion to the first position from a second position in which the clearing portion is spaced from the region between adjacent flutes of the drill.

15. A method as claimed in Claim 13 or 14 comprising moving successive clearing members of the clearing portion into the first position when clearing the drill.

16. A method as claimed in Claim 15 comprising pivoting the clearing members such that successive members are brought into the first position.

17. A method as claimed in Claim 15 or 16 comprising driving the clearing members such that successive members are brought into the first position.

18. A method as claimed in Claim 17 comprising driving the members with a slip drive.

19. A method as claimed in any of Claims 13 to 18 comprising presenting a negative rake angle to the shaft af the drill with the clearing portion or clearing members when the clearing portion or clearing members are in the first position.

20. A method as claimed in any of Claims 13 to 19 comprising the clearing portion or the clearing members abutting the shaft of the drill when in the first position.

21. A method of clearing a drill substantially as herein described with reference to, and as shown in the accompanying drawing.

22. A method of clearing a drill as claimed in any of Claims 13 to 21 using a clearing device as claimed in any of Claims 1 to 12.