A Drill Bit and A Plug The present invention relates to a drill bit and a plug.
In particular, the drill bit is for use on a hand held, manual or electrically powered, drily.
The drill bit is designed to shape an existing hole in a partition (for example, a wall., a floor or a ceiling) of a building. The plug can then be placed in the shaped hole in the partition so as to make good the partition.
Currently, when electricians, plumbers and any other persons require access to subflooT area$ or wall cavities, gaining such access is time consuming, typically involving the lifting up of floorboards, the cutting of chipboard floor boards, which often necessitates removing lots of furniture/carpets. The floor then has to be repaired which can be costly and in the case of chipboard, difficult to do to a satisfactory standard. Gaining access to plasterboard wall cavities is difficult to achieve without destroying fairly large portions of the plasterboard. The plasterboard then has to be repaired, probably replastered and redecorated, which can be time consuming and expensive. it is known to use a router to cut a hole in a partition. Such methods are fairly complicated, typically requiring a template attached to the partition, and then the router must be moved circularly across the material to make a hole iu the partition.
An aim of the invention is to provide a simpler method of making holes in partitions.
According to a first aspect of the invention there is provided a drill bit comprising a body, the body comprising an at least partly generally truncated cone shape, The drill bit can be attached to a drill, which can be moveably operated in the axial direction of the drill bit to remove material from a partition. The drill bit in accordance with the invention is simpler than the aforementioned router.
The drill bit body may comprise a conical shape. Preferably, the drill bit body comprises only a truncated cone shape, i. e. the drill bit has no pointed tip. Such a pointed tip can cause damage to pipe work and electric's located behind a partition and unsighted to the user of the drill.
The diameter of the drill bit body is preferably sufficient to enable a hole big enough for an adult person to pass their hand through it, e. g. to work on the blind side of the partition. The diameter of the body may be between 10 cm and 20 cm. Most preferably, the diameter of the body is between 10 cm and 15 cm.
The drill bit preferably has an integral hole saw blade at its foremost end. Such an integral hole saw blade permits, with just one drill bit, and in one single axial movement, a hole e to be first drilled by the bole saw blade, and the hole then to be shaped by the at least partly generally truncated cone shape body_ The body preferably has material removal means-The material removal means preferably comprises a blade arrangement. The blade arrangement comprises at least one blade on the circular periphery of the body. In one preferred embodiment, the blade <BR> <BR> <BR> <BR> <BR> arrangement comprises three blades. In another preferred embodiment multiple blades are arranged to"grare"me partition material. Where a plurality of blades are employed, the blades are preferably equally spaced about the periphery of the body. The foremost centre point of the drill bit is blunt.
Instead of a. blade arrangement, the material removal means may comprise abrasive means designed to wear away the material of a partition.
The drill bit preferably comprises a collar arranged to act as a depth stop-The collar preferably comprises a plurality of (integral) collar parts. The number of collar parts may correspond to the number of blades. The collar parts preferably define annular spaces between them to allow material surrounding a hole in a partition to be removed and to escape. Where a plurality of blades are ezuployed, the spaces preferably coincide with the location of the blades. One preferred embodiment of the drill bit has three collar parts.
Where blades are not employed, a plurality of collar parts preferably defines a plurality of spaces.
The drill bit is preferably'fitted to an electrically powered drill. The drill bit can alternatively be arranged on a manually operated drill. The drill may be hand held or bench mounted.
According to a second aspect of the invention there is provided a drill having a drill bit in accordance with the first aspect of the invention fitted thereto.
According to a third aspect of the invention there is provided a plug for arrangement in a hole in a partition of a building such as wall, ceiling or floor, the plug having a generally truncated cone shape.
The plug is preferably of a diameter to fit a hole big enough for an adult persons'hand to pass through it. The plug diameter may be between 10 cm and 20 cm. Most preferably the plug diameter is between 10 cm and 15 cm.
The plug may comprise a periphery which is only in part a generally tnmncated cone, e. g- at a jfbremost narrow diameter end of the plug.
An edge defined by the rearmost larger diameter end of the plug and the conical surface of the plug may be rounded.
The plug may be @ made from MDF or plaster or any material with matches the partition material. The plug may be made of any material strong enough to bear the weight of a person once the plug is installed in a partition. According to a fourth aspect of the invention there is provided a partition having a hole therein, the hole comprising the plug in accordance with the third aspect of the invention fitted therein.
The partition may have a hole of generally truncated cone shape or partly generally truncated cone shape. The plug is preferably adhered in place-using glue. Alternatively the plug may be frictionally located. The rear most end of the plug may lie approximately in line with the facing surface of the wall. The plug may be arranged to lie inbound of the facing surface of the partition. For example, in one embodiment, the depth of the plug may be reduced with respect to the depth of the partition so as to permit the rearmost end of the plug to lie inbound of the facing surface of the partition.
The depth of the plug may also be increased with respect to the depth of the partition.
The plug may be made of the same material as the partition.
According to a fifth aspect of the invention there is provided a kit of parts, the kit comprising a bit in accordance with first aspect of the invention and a plug in accordance with third aspect of the invention.
Preferably, the kit comprises a plurality of similar plugs.
Preferably, the kit comprises a hole saw attachment for a drill_ Preferably, the plug is manufactured to approximately match the dimensions of the body of the dull bit.
According to a sixth aspect of the invention there is provided a method of making a hole in a partition of a building, the method comprising fitting the drill bit in accordance with the first aspect of the invention to the drill, then arranging the drill bit in the hole, and using the drill bit, axially drilling to form a generally truncated cone shaped bore in the partition.
Preferably, the method includes the step of drilling a hole through the partition using a drill having a parallel sided hole saw attachment, So as to create the hole for the drill bit in accordance with the invention prior to drilling with the drill bit.
The method may further comprise repairing the hole by inserting a plug in accordance with the third aspect of the invention in to me tapered hole. Preferably the method comprises gluing the plug in the generally truncated cone shaped bore m the partition.
A bit and plug in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side view of a bit in accordance with the invention :, Figure 2 is a view of the bit of Figure 1, taken in the direction of the arrows U-11, Figure 3 is a side view of a plug in accordance with the invention, Figure 4 is a view of the plug of Figure 3 taken in a direction of the arrows IV-IV, Figure 5 is a schematic view of a wall of a building, a hole in the wall havidg been shaped by the bit, and having the plu-shown in Figures 3 and 4 installed therein, Figure 6 is a perspective view of an alternative embodiment of the bit (shown without a blade or mounting shaft), Figure 7 is a side view of the bit of Figure 6, Figure 8 is a view of the bit of Figure 7 taken in the direction of the arrows VI-VI, Figure 9 is a view of the bit of Figure 7 taken in the direction of the arrows V Figure 10 is a view of the plug with a hole drilled through the centre and a tolerance fit dowel partially inserted in the hole Figure 11 is a view of the plug of figure 10 taken in the direction of the arrows X-X, and Figure 12 is a view of the plug with the dowel inserted and knocked through to provjde a flat surface on the larger diameter side Reiemng to Figure 1, a drill bit 10 in accordance with the invention, comprises a shaft 12, and a collar 14 and a body 16 6 ranged coaxially therewith.
The shaft 12 has a hexagonal cross-section, seen by ths hidden detail in Rgure 2, which allows it to be fitted to a hand held, electrically powered, drill.
The body 16 has a generally truncated cone shape. The diameter of the body l 6 is conveniently about 15 cm, although, functionally speaking, the diameter of the body need only be such as to provide a hole sized to allow a person to put their hand through a hole formed in a partition by the drill bit body so as to carry out work on the blind side of the partition.
The body 16 comprises a blade arrangement, which, in the embodiment shown in Figures 1 and 2 of the drawings, comprises three blades 18 (only two are shown in Figure 1, and only one is shown in Figure 2) arranged on the periphery of the body. A different number of blades could be employed but, particularly with a. body diameter of this size, three blades has been selected as an optimum number. The three blades 18 are equally spaced at interval of approximately 120 degrees about the periphery of the body 16. Each of the three blades 18 is arranged in a recess 20, formed in me body by any suitable means. Obviously, each blade 18 is arranged in its recess 20 so that the cutting tip of the blade protrudes beyond the periphery of the body 16. In the embodiment shown the blades 18 are arranged at an angle of approximately 30 degrees to the tangent of the periphery of the body 16. Each blade 18 is removably fixed to the body 16 by screws 22 or other suitable fasteners. Cavities 24 precede the blades 18 to allow material surrounding a hole in a partition to be removed and to escape.
The collar 14 comprises a number of collar parts corresponding to the number of blades, i. e. in the embodiment shown, three collar parts 26. The three collar parts 26 define annular spaces between them, of equal size, each of which spaces coincides with the location of one of the blades 18-Each collar part 26 extends for approximately 90 degrees of the circumference of the body so as to, collectively, provide a collar 14 which acts as a reliable depth stop for the bit 10.
Referring to Figures 3 and 4, a plug 30 in accordance with the invention is manufactured to approximately matching dimensions to the body 16 of the bit 10. The plug 30 can be made of the same material as the hole which is filled, or conveniently made from MDF or plaster, or any other suitable material. However, in another embodiment7 it should be noted that the plug need only have a periphery in part of generally truncated cone shape, e. g. at either a foremost (narrow diameter) end 32 of the plug (i. e. the right hand side of the plug in Figure 3) or at a rearmost end.
An edge 34 defined by ths meeting of the rearmost (larger diameter) end 36 of the plug 30 (i.e. the left hand side in Figure 3) and the conical surface of the plug may be rounded. Such a rounded edge 34 allows for a'filler material to key into the space denned by the wall and the plug 30 when the plug is fitted into the hole.
Figure 5 shows a partition such as a plasterboard wall 40-Initially, a conventional parallel sided hole saw attachment of the correct size is fitted on a standard, hand held, electric drill (not shown for conciseness ? The wall 40 is drilled through using the hole saw attachment leaving a parallel sided bore through the wall. Other means can be employed to establish a hole in the partition, e. g. a hole can be hammered in the partition when it is made of plasterboard.
The drill bit 10 shown in Figures 1 and 2 can then be arranged on the drill and used to create a tapered hole 41 in the wall.
The drill bit 10 need only drill along part of the parallel sided hole in the wall, e. g. the foremost part of the parallel sided hole, to provide a hole having at least a partly tapered profile. It may be convenient for the diameter of the hole formed by the hole saw attachment to be slightly greater than the diameter of the foremost (narrow) end 32 of the drill bit 10 so as to allow the blades 18 of the drill bit to penetrate the hole and engage the material surrounding the hole which is to be cut. Such a relationship between the drill bit 10 and the parallel sided hole saw attachment can result in the furthest part of the parallel sided hole remaining undrillcd.
The depth of the plug may be reduced so as to permit the rear most end of the plug to lie inbound of the facing surface 42 of the partition. However, in the embodiment shown, the drill bit 10 bores substantially completely through the parallel sided hole in the wall, giving rise to a hole 41 of generally truncated cone shape. The collar 14 of the bit 10 acts as a depth stop, which results in a consistently accurate, standard sized/ shaped hole regardless of the depth of the material being cut. This then allows the insertion of the plug 30, foremost end 32 first, into the hole 41. The plug 30 can then be glued in place to create a strong surface repair. It can be seen that the rear most end 36 of the plug lies approximately in line with the facing surface 42 of the wall.
This tool/system allows the very quick cutting of any number of tapered access holes which can then be very quickly and efficiently repaired without the need ofprofessionaj help or equipment The advantages of the system are that it is quick, cost effective, involves minimal damage to the partition, requires no other specialist tools ;, relatively cheap set up costs, eliminates the necessity of professional help such as plasterers, and is easily used by DIY enthusiasts, Only one sized plug 30 is required for repairing all floor repairs and one for all plasterboard repairs. Indeed, a single size plug can be used for repairs to floors, walls and ceilings. A tapered plug of the sort described herein is stronger than a prior art stepped plug, for example because the tapered plug uses the whole depth of the partition for the repair. Also, the tapered plug can be used to repair a partition of any thickness, even a. vCiy Ulin partition, because the partition wil] not be weakened by the cutting of an over deep rebate in the partition.
The centre of the narrow end 32 of the body 16 may have a recess (not shown). The recess can take a nut. The end of the shaft 12 fitted to the collar (i. e. the end remote from the drill) can be passed through the collar and body and held place by locatiw a nut in the recess and fastening the nut on a screw threaded portion of the shaft. The end of the shaft ; 12 which abuts the ilange may be flared so as to strengthen the shaft. The shaft : 12 can be of circular cross section.
It should be appreciated that the body 16 may comprise abrasive means to grind away material instead of the aforementioned blades 18 which cut away material.
In an alternative embodiment of the invention, the electrically powered drill need not be hand held. Moreover, the drill bit 10 can be arranged on a manual dull.
The drill bit can. take me form of a collar 14 and body 16 which is fitted to a commercially available'hole saw arbour'as an alternative to the hexagonal shaft 12.
It has been found to be advantageous to fit the drill bit to a commercially available arbour which can be inexpensive to buy and are readily available to fit different sorts of drill chucks.
The blade arrangement comprises a single blade, Figure 6. Although the blade is not shown, the blade is fitted to a blade-f'ix block 100 It has beell found to be advantageous to use a. single blade to eliminate judder, which can be associated with having a multiplicity of blades.
A counterbalance is provided 102. When a single blade is used it can be advantageous to balance the drill body (Figure 6) by provision of a counterbalance 102. The counterbalance has a similar mass to the blade and blade-fixing block 100. The counterbalance is conveniently a part of similar density and volume to the blade and blade-fixing block 100. The counterbalance can be positioned diametrically opposite the blade and blade-fixing block. The counterbalance further improves the performance of the drill bit.
The collar arrangement comprises a single collar part 104. The collar 104 and the body are made, by casting, from a single piece of material (Figure 6).
Referring to Figures 10, 11 and 12, the plug can be provided with a hole 106 drilled through the centre and a tolerance-fit dowel 108 partially inserted in the hole. The protruding dowel can be used to aid positioning the plug in the hole in the wall or floor. After the plug has been positioned and glued in the hole, the dowel 108 can be knocked through to provide a flush surface 36.
