NZ520150A - Suction head, core bit and extension piece for dry drilling - Google Patents

Abstract

A suction head, core bit and extension piece designed to be fitted together with co-operating nut featuring a movement resisting means.

Description

NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION After French Patent Application No. 01 09 276 filed 12 July 2001 Davies Collison Cave Reference: 2550481 APPLICANT(S) Toolmatic BVBA Cardijnlaan 3, 8600 Diksmuide, BELGIUM ADDRESS FOR SERVICE: DAVIES COLLISON CAVE Patent & Trade Mark Attorneys c/- James & Wells Level 9, Ellerslie Tower 60 Cawley Street, Ellerslie, Auckland New Zealand INVENTION TITLE: Suction head, core bit and extension piece for dry drilling We/I, Toolmatic BVBA hereby declare the invention for which we pray that a patent be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: Intellectual Property Office of NZ 12 JUL 2002 received P:\REC\JMF\13493.doc - 9/7/02 - 1 a- The field of the invention is that of dry drilling in building materials such as bricks, cellular-concrete/plaster combinations, stone and render.

For that, use is made of a core bit or drill bit, which is generally in the form of a tube, and with diamond-encrusted segments attached, for example by brazing, to one of the edges of one of its ends. The core bit is 10 rotated by means of a drilling rig. Inserted between the core bit and the drilling rig is a suction head for sucking out the dust generated by the drilling around the core. A suction head has a drive shaft, driven at one end by the drilling rig and at the other end 15 driving the core bit.

Collaboration between the suction head and the drilling rig is via a screw and nut head or double-screw adapter.

Collaboration between the suction head and the core bit is a collaboration of the bayonet type, with transverse keys on a plug-in end of the drive shaft of the head and slots for accommodating the keys on a tubular 25 socket formed at the drive end of the core bit.

A screw thread, formed at the surface of the shaft, takes a tightening and locking nut of the bayonet fitting, the nut being screwed' on until it comes into 3 0 abutment against the annular end edge of the bayonet socket of the core bit.

The drive shaft of the suction head is mounted in a rolling bearing cage into which a suction outlet pipe, 3 5 generally screwed into the wall of the cage, emerges. Naturally, the drive shaft is pierced with apertures for the passage of dust so as to ensure communication between the suction outlet and the interior of the drive shaft.

P:\OPER\Arl\520150nz spe.doc-11/02/03 52 0 0 When the axial length of the core bit is not sufficient, an extension piece is fitted between the core bit and the suction head, and this extension piece comprises, at one end, a plug-in keyed end, like the suction head, and, at the 5 other end, an end with a bayonet socket, like that of the core bit, and which also, like the suction head, has a tightening and locking nut.

The Applicant has noticed that when the core bit-suction 10 head assembly is in operation, with or without an extension piece, the tightening and locking nut belonging to the suction head or to the extension piece, tended to slacken off and therefore no longer lock the core bit in place.

One aspect of the present invention provides a suction head designed to, by way of drilling element, be mounted on a drilling rig and take the driven end of a core bit or of an extension piece inserted between the suction head and the core bit, a tightening and locking nut being mounted on the 20 head to be moved thereon into abutment against the said driven end and thus lock the core bit or extension piece, wherein the tightening and locking nut comprises means for resisting movement of the nut away from the said driven end, said movement resisting means being co-operable with the 25 driven end.

It will be noted here and now that the applicant does not exclude, going beyond a bayonet-type mounting, that the securing-together of each pair of items, suction head, core 30 bit and extension piece, might also be by screw fastening.

Naturally, the movement resisting means could just as well P:\OPER\Arl\520150 nz spc.doc-11/02/03 -3 be provided on the drive end of the core bit and of the extension piece and on the tightening and locking nut of the extension piece.

Thus, another aspect of the present invention provides a core bit designed to, by way of drilling element, via a driven end, be received on a suction head received on a drilling rig, or on an extension piece inserted between the core bit and the suction head, the driven end being designed 10 to act as an end stop for a tightening and locking nut mounted so that it can move along the suction head or along the extension piece and thus lock the core bit, wherein the drive end comprises means for resisting movement of the tightening nut away from the said driven end of the core 15 bit, said movement resisting means being co-operable with the tightening nut.

A further aspect of the present invention also provides an extension piece designed to, by way of drilling element, be 20 mounted, via a driven end, on a suction head mounted on a drilling rig and to take, via a driving end, the driven end of a core bit, a first tightening and locking nut being mounted so that it can be moved into abutment against the driven end of the core bit and thus lock the core bit, and 25 the driven end of the extension piece being designed to act as an end stop for a second tightening and locking nut mounted so that it can move along the suction head and thus lock the extension piece, wherein at least one of said first tightening nut and said driven end of the extension piece 30 comprises means for respectively resisting movement of the first tightening nut or second tightening nut away from the driven end of the core bit or from the driven end of the P:\OPER\ArI\520l50 nz spe.doc-11/02/03 extension piece, said movement resisting means being co-operable with the driven end of the core bit or second tightening nut, respectively.

As a preference, the movement resisting means comprise transverse friction means, that is to say one running more or less in a plane perpendicular to the axis of the core bit, for example a knurled transverse annular surface or, better still, there is provided, in a frontal annular 10 groove, an 0-ring made of a material with a relatively high coefficient of friction, of the rubber type. It is also conceivable, by way of resisting means, to have a surface which is raised by a number of pegs or beads with a high coefficient of friction, or even a washer of the Belleville 15 type.

A preferred embodiment of the present invention aims to avoid the above stated disadvantage of the prior art.

Preferred embodiments of the present 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 the core bit; Figure 2 is a perspective view of the suction head; Figure 3 is a perspective view of a double-screw adapter; Figure 4 is a perspective view of a screw and nut head adapter; Figure 5 is a perspective view of an extension piece, and P:\QPER\Arl\520l50nz spe.doc-11/02/03 -4A- Figure 6 is a view in axial section of the assembly of the core bit and of the suction head, in the left-hand half view, and the nut being out of the locking position and, in the right-hand half view, the nut being in the locking 5 position, in abutment against the core bit.

The core bit 1 in Figure 1 is a tube of axis 2, comprising a driven end 3 and a drilling end 4. Attached, here by brazing, to the edge 5 of the drilling end 4 are three 10 diamond-encrusted segments 6.

The driven end 3 of the core bit here is a bayonet socket with its slots 7 for accommodating drive keys of a suction head or of an extension piece, as will be seen hereinafter. 15 The driven socket 3 of the core bit 1 has an annular free edge 8.

The driven bayonet socket 3 is designed to be received on a suction head (Figure 2) or on an extension piece (Figure 5) and to act as an end stop for a tightening and locking nut.

The suction head 11 in Figure 2 comprises a driving mandrel 12, of axis 13, driven at one end 14 by a drilling rig, via an adapter, and at the other end 15 driving the core bit 1 via the driven socket 3 of the core bit fitted onto the driving end 15 of the mandrel 12 or an extension piece.

The person skilled in the art does not speak of the mandrel but of the drive shaft.

The driving or plug-in end 15, of the head carries, driven in transversely and by force, a locking key 16 with two ends 17, 18 which project to act as locking studs once they have been accommodated in the slots 7 of the socket 3 of the core bit.

A screw (not shown) is formed at the surface of the mandrel 12 and receives, screwed onto this screw thread, a tightening and locking nut 20.

The mandrel 12 is mounted in a rolling bearing cage 21 into which a suction outlet pipe 22 emerges.

Via apertures formed in the mandrel, the latter communicates with the suction outlet pipe 22 .

The adapter 31 in Figure 3 is a double screw adapter, a first screw 32 screwing into the end 14 of the mandrel 12 of the suction head 11, and a second screw 33 screwing into the drilling rig. As to the adapter 41 of Figure 4, unlike the one in Figure 3, it fits onto the drilling rig via a nut head 42, in fact the head of the screw 43 for fitting to the suction head.

The extension piece 51 in Figure 5 consists of a tube 53 of axis 52 with, at a driven end, a bayonet v - 6 - socket 58, like the driven socket 3 of the core bit 1 and, at an opposite driving end, with an assembly 54 identical to that of the suction head 11 and comprising a locking key 55 and a tightening and locking nut 5 6 5 screwed onto a screw thread 57 of the tube 53. The socket 58 is intended to be fitted onto the suction head and the driving assembly 54 to be plugged into the driven socket 3 of the core bit 1.

In the example under consideration, the nut 20, screwed onto the mandrel 12 of the suction head 11, comprises, emerging on the frontal transverse annular surface 61 facing towards the core bit 1 when the latter is fitted onto the mandrel 12 (Figure 6) , a frontal annular 15 groove 62 housing an O-ring 63, in this instance made, of rubber.

When the core bit 1 has been fitted onto the mandrel 12 of the suction head 11 and the key 16 has been engaged into the bottom of the slots 7 of the driven bayonet socket 3 of the core bit 1, the nut 2 0 is screwed along the mandrel 12 until the frontal surface 61 comes into abutment against the annular edge 8 of the driven socket 3 to tighten and lock the core bit against the suction head.

This coming into abutment crushes the O-ring 63 (right-hand part of Figure 6) which can then, through friction, perform an antirotation function discouraging the nut 20 from working loose and moving away from the core bit.

Naturally, the groove with its antirotation O-ring could be provided, not in the frontal surface of the nut, but in the frontal annular edge 8 of the driven bayonet socket 3 of the core bit.

Likewise, and considering the extension piece 51, the groove and its antirotation ring could also be provided either on the frontal surface 71 of the tightening and locking nut 56, screwed onto the driving end 73 of the tube 53, or on the frontal annular edge 72 of the bayonet socket 58 constituting the driven end of the extension piece 51, or on both.

As an alternative, the transverse annular surface 61 could be knurled.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims (11)

P:\OPER\Arl\520l50 oz spc.doc-11/02/03 5201 -8- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A suction head designed to, by way of drilling element, be mounted on a drilling rig and take the driven end of a 5 core bit or of an extension piece inserted between the suction head and the core bit, a tightening and locking nut being mounted on the head to be moved thereon into abutment against the said driven end and thus lock the core bit or extension piece, wherein the tightening and locking nut 10 comprises means for resisting movement of the nut away from the said driven end, said movement resisting means being co-operable with the driven end.

2. A core bit designed to, by way of drilling element, via 15 a driven end, be received on a suction head received on a drilling rig, or on an extension piece inserted between the core bit and the suction head, the driven end being designed to act as an end stop for a tightening and locking nut mounted so that it can move along the suction head or along 20 the extension piece and thus lock the core bit, wherein the drive end comprises means for resisting movement of the tightening nut away from the said driven end of the core bit, said movement resisting means being co-operable with the tightening nut. 25

3. An extension piece designed to, by way of drilling element, be mounted, via a driven end, on a suction head mounted on a drilling rig and to take, via a driving end, the driven end of a core bit, a first tightening and locking 30 nut being mounted so that it can be moved into abutment against the driven end of the core bit and thus lock the core bit, and the driven end of the extension piece being P:\OPER\Arl\520150nz spe.doc-11/02/03 5 -9- designed to act as an end stop for a second tightening and locking nut mounted so that it can move along the suction head and thus lock the extension piece, wherein at least one of said first tightening nut and said driven end of the 5 extension piece comprises means for respectively resisting movement of the first tightening nut or second tightening nut away from the driven end of the core bit or from the driven end of the extension piece, said movement resisting means being co-operable with the driven end of the core bit 10 or second tightening nut, respectively.

4. A drilling element according to one of Claims 1 to 3, in which the movement resisting means comprise transverse friction means.

5. A drilling element according to Claim 4, in which the movement resisting means comprise, in a frontal annular groove, an O-ring made of a material with a relatively high coefficient of friction.

6. A drilling element according to Claim 5, in which the O-ring is made of rubber.

7. A drilling element according to any one of Claims 4 to 25 6, in which the movement resisting means comprise a knurled transverse annular surface.

8. A drilling element according to any one of Claims 4 to 7, in which the movement resisting means comprise a surface 30 which is raised by a number of pegs or beads with a high coefficient of friction. 15 20 P:\OPER\Arl\520150 az spe.doc-13/02/03

9. A suction head substantially as hereinbefore described with reference to the drawings.

10. A core bit substantially as hereinbefore described with reference to the drawings.

11. An extension piece substantially as hereinbefore described with reference to the drawings. end of claims DATED this 13th day of February, 2 0 03 Toolmatic BVBA By DAVIES COLLISON CAVE Patent Attorneys for the Applicant