DEVICE FOR DRILLING A CONICAL ZONE IN A HOLE

Abstract: The present invention relates to a device for drilling a conical area in the innermost part of a previous drilled cylindrical hole. The invention provides a safe and durable fastening for screws and bolts. The device is suitable for drilling in concrete, rocks and other solid materials.

Description: Device for drilling a conical zone in a hole The invention regards a device for drilling a conical zone at the bottom of a predπlled cylindrical hole The device is especially intended for drilling in concrete, rock, stone and other solid materials The device of the invention makes it possible to provide secure anchorage for a taper bolt at the bottom of the drilled hole It is pre iously known that a certain amount of conisitv may be formed at the bottom of a drilled hole, and that this may be done by use of v arious types of devices and dπlls A 10 great drawback to these solutions is the fact that they are complicated and often do not give satisfactory results, in addition to the fact that no compressed air or dπll fluid is fed to the hole duπng drilling This results in the drilled materials remaining at the innermost end of the hole and having to be removed by means of e g compressed air after the conical area has been dπlled Unlike these known solutions, the device of the ι> invention ensures that compressed air is introduced, so as to remove the drilled mateπals while the dπllmg takes place. The basis of the invention is the fact that it is often difficult to create solid and firm anchorage points m rock, stone, concrete and similar hard mateπals It turns out that 20 only cylindrical holes are normally dπlled for fixing bolts and screw s in these materials In other words, the bolts are only held by the fπctional forces between the bolt and the cyhndπcal, straight wall Use of the device of the invention to dπll a conical area at the bottom of a cy ndncal :-■ hole will provide a much stronger and firmer anchor at the innermost end of the dπlled hole Various ways of dπlling conical holes ha e previously been descπbed EP 704 226 is especially aimed at a device for dπlling holes m face tiles DE 2 415 240 describes a "o method and device for dπlling conical holes US 5 829 925 descπbes a dπll with a cutting device at the end, which device may be forced out by means of pressuπsed dπll fluid US 4 978 258 is aimed at a drilling tool with a swing-out head for drilling cavities The present invention regards a device for drilling a conical zone at the end of a predπlled cylindrical hole in rock, stone, concrete, bricks or other dnllable mateπal for fixing screws, safety bolts, the device being characterised in that it compπses a replaceable drill head coupled to a swing-out cone joint with a resilient O-πng, where the ball joint is attached to the dπll head by use of a through bolt, and where the dπll head, the bolt, the ball head w ith the cone joint hav e through holes for introduction of compressed air or dπll fluid for removal of dπlled mateπals 10 By both the dπll head and the cone joint having through holes for introduction of compressed air or drill fluid, even at all angles of the cone joint, the drilled hole ill at all times be free of drilled materials, cuttings and other loose materials W en dπlling large holes in rock and coning the lower part of the hole, great forces iι must be applied to the actual drill head in the form of powerful blows and rotation The de ice of the invention is formed with a ball joint in which the actual ball is to withstand the percussion forces applied and a sturdy through bolt is to withstand the rotational forces :o The invention will now be explained in greater detail by means of the figures, in which Fig 1 shows a cross section of the entire dπll head with a ball-attached joint and a swmg-out cone joint, Fig 2 shows a cross section of the cone joint, seen from the side. Fig 3 shows a top view of the drill head, 2 . Fig 4 shows a conventional rock drill at the bottom of a drilled hole. Fig 5 shows the cone joint of the invention while dπlling a conical bottom. Fig 6 shows an example of a taper bolt that has been hammered down and secured o Figures 1. 2 and 3 show the dπll head 1 w ith a threaded portion 3 that is screwed onto a dπll rod The cone joint 2 that can be forced outwards to dπll a conical hole is attached bv use of a through bolt 4 The bolt 4 has a hollowed out area 14 in the middle, so as to allow compressed air to pass through in all positions of the cone joint 2 Carbide segments 5 have been mounted on the side of the cone joint 2 facing the dπlled hole These will ensure quicker, improved dπlling of the conical area and make the dπll more durable A central passage 1 1 and 13 for introduction of compressed air goes through the dπll and the cone joint 2 A hollow ed out area 12 exists in the region between the cone joint 2 and the dπll head, the function of which area is to ensure the free passage of compressed air even when the cone joint 2 is in its extreme position In figure 1 , the broken line 9 illustrates the bottom of the drilled hole, and the broken line 8 shows the ready dπlled conical zone A rubber O-πng 15 is fitted to the upper part of the cone joint 2. the effect of which is to force the cone joint back to its oπginal position after lo dπlling The lower edge of the cone joint 2 is rounded with a bevel 6 When the cone joint 2 reaches the ready dπlled position, the cone joint will come to a stop against the lower stop edge 10 of the dπll head Thus this edge ensures the maximum deflection of the cone joint I -Ϊ Figure 3 shows the drill head 1 with the cone joint 2 seen from above, with carbide segments 5 The through bolt 4 is indicated by broken lines, and provides swivelling attachment of the cone joint 2 to the dπll head Figure 4 shows a con entional rock drill 16 dπlling a cylindrical hole in rock 17 The 20 dπlling is carried out until the hole has reached the desired depth 9 Figure 5 shows the hole dπlled in Figure 4, but with the cone joint 2 mounted on a dπll head and a conical hole 8 drilled at the bottom of the hole Due to the lower bevel 6 of the cone joint, the joint will, as a result of rotation and hammeπng on the dπll head, be 2^ forced outwards and will drill a conical hole 8 The swivel radius of the cone part is limited as it hits the lower stop edge 10 When the conical hole is ready drilled, the rotation and hammering on the dπll head is stopped At this point the rubber O-πng 15 will force the cone joint back to its original position, to allow the whole thing to be withdrawn from the hole Drilled mateπals ill already hav e been carried out of the o hole by compressed air Figure 6 shows an example of a taper bolt 18 that has been inserted into the hole A pipe 19 is then placed around the outside of the taper bolt 18 and knocked down towards the bottom of the hole As a result of the force applied during the hammering, the pipe 19 is forced out by the conical part of the bolt 18 and fills the surrounding space This provides a very safe fixing and anchoring system The diameter, length and angle of the cone joint may be adapted to the desired dimensions The entire dπll head and the cone joint are preferably provided with standard special threads These are matched to the thread used on dπll rods for drilling in rock, stone, lo concrete and similar, for securing and anchoring conventional rock safety bolts and other fastening devices. By using special standard thread, drill heads and cone joints may be replaced quickly i -

Claims: C l a i m s 1 A device for dπlling a conical zone at the end of a drilled cylindrical hole in rock, stone, concrete or other dnllable mateπal, for fixing screws, safety bolts or similar, c h a r a c t e r i s e d i n that the device compπses a drill head (1) coupled to a swmg-out cone joint (2) with a flexible and resilient O-πng (15). and the dπll head and the cone joint have a through passage (11, 13) for introduction of compressed air or dπll fluid 0 2 A device according to Claim 1 , c h a r a c t e r i s e d i n that the swing-out cone joint (2) is attached to the drill head (1) via a solid through bolt (4), the cone joint (2) may swing s out to a predetermined radius (8) by coming to a stop against an edge (10) at the bottom of the dπll head 3 A device according to Claims 1 - 2, 0 c h a r a c t e r i s e d i n that the cone joint (2) is equipped with at least one, preferably three longitudinal carbide segments (5) 4 A device according to Claim 1 , - c h a r a c t e r i s e d i n that the O-πng (15) on the cone joint (2) is preferably made from a flexible, resilient rubber 5 A device according to Claims 1 - 4, o c h a r a c t e r i s e d i n that compressed air may be introduced through the passages (11, 13) A device according to Claims 1 - 5, c h a r a c t e r i s e d i n that the device is equipped with standard ϊ thread, so as to allow it to be coupled to commonly used drill rods. 7 A device according to Claims 1 - 6, c h a r a c t e r i s e d i n that the cone joint (2) has a hollowed out o area (12) at the top in order to enhance the transfer of compressed air between the passages (11) and (13). 5

Inventors: FAANES PER AAGE, FAANES, PER, AAGE
Applicants: FAANES PER AAGE, QUICK ANCHOR AS, FAANES, PER, AAGE
Application year: 2000
Main classification: B23B41
IPC codes: B23B41, B23B51, B28D1