GB2540803A - Drill bit cooling device - Google Patents

Abstract

The cooling device, for use with a drill bit 1 of a power tool, includes an open-cell foam structure 15 configured to absorb water into which it is placed. The sponge is attached to the drill bit via means 17 which allows it to surround the bit. The attachment means may be a coupling such as an annular cup. The device is used in a method of cooling a drill bit by placing the sponge in water, attaching the sponge to the drill bit and actuating the bit to drill into a surface 31. As the drill bit moves into the surface, the sponge is compressed by the surface such that water is expelled from the sponge to cool the bit.

Description

DRILL BIT COOLING DEVICE

The present invention relates generally to a drill bit cooling device and a method of cooling a drill bit when in use and finds particular, although not exclusive, utility in cooling drill bits during drilling of ceramic tiles.

Drill bits, for instance those used with hand-tools and power-tools, are prone to overheating, and this is most common when drilling ceramic tiles. It is known to try to cool such drill bits during drilling, for instance by holding a water-soaked cloth or sponge against the surface to be drilled; however, such manual systems are difficult for a lone operator to use, particularly whilst maintaining a high degree of personal safety.

According to a first aspect of the present invention, there is provided a drill bit cooling device, for use with a drill bit of a power tool, the device comprising: an opencell foam sponge configured to absorb water into which it is placed; and means for attaching the sponge to the drill bit such that the sponge substantially surrounds the drill bit.

In this way, as the drill bit is actuated to drill into a surface, and thereby moves into the surface to the surface, the sponge is compressed by the surface such that water is expelled from the sponge.

The drill bit may comprise a wood, metal, masonry and/or ceramic-tile drill bit, which may have a drill bit head. The drill bit may comprise a hole cutter and/or hole saw. The drill bit may comprise a hole cutter and a drill bit head, arranged axially with respect to one another, for instance in relation to a shank of the drill bit. The drill bit head may comprise a tungsten carbide and/or diamond tip. A cutting edge of the hole cutter may comprise diamond and/or tungsten carbide.

The sponge may comprise a reticulated sponge. The sponge may comprise natural sponge, cellulose wood fibres and/or foamed plastic polymers. In particular the sponge may comprise low-density polyether, PVA, and/or polyester, more particularly double-blown polyester.

The sponge may be annular in form, for instance toroidal; however, other non-toroidal annular shapes, such as irregular and asymmetric shapes are envisaged. The sponge may have a hole for passage of the drill bit therethrough. The hole may extend through an axial centre of the sponge. The sponge may be substantially linear and may be configured to wrap around the drill bit. The sponge may have any other suitable shape. When in use, the sponge may have an annular cross section that tapers toward the head of the drill bit.

The sponge may be fixedly attachable to the drill bit, such that rotation of the drill bit about its drilling axis may cause the sponge to rotate about the same axis. Alternatively, the sponge may be rotatably mountable on the drill bit, such that rotation of the drill bit about its drilling axis may induce substantially no rotational movement of the sponge. As a further alternative, the sponge may be couplable to the drill bit by a friction fit, such that rotation of the drill bit about its drilling axis at a first rotational speed may cause the sponge to rotate about the same axis at the first rotational speed, and rotation of the drill bit about its drilling axis at a second rotational speed may cause the sponge to rotate about the same axis at a rotational speed less than the second rotational speed, for instance the sponge may not rotate.

The sponge may be attachable to the drill bit at an end of the sponge distal from the drill bit head. In particular, when attached to the drill bit an end of the sponge proximal to the drill bit head may be substantially unattached. In this way, the sponge may be compressed from an end adjacent to the drill bit head towards the end distal from the drill bit head.

The means for attaching the sponge to the drill bit may be a coupling. The coupling may be disposed on the sponge at one end of the sponge.

The coupling may comprise an annular cup into which the sponge is received/receivable. The sponge may be held within the annular cup by a friction fit; however, in alternative embodiments other holding means may be used, such as glue.

The annular cup may be attachable to the drill bit by means of one or more clamps, grub screws, bolt, nuts, screws, glue, welding, or any other similar fixing means. The annular cup may have an exterior wall and a base. The base may have a hole for receiving the drill bit therethrough. The annular cup may have an interior wall disposed to be substantially adjacent to the drill bit when in use. The sponge may be configured to sit within the annular cup with an end distal from the drill bit head (when in use) that is in contact with the base and the exterior wall, and optionally the interior wall.

The drill bit cooling device may further comprise a drill bit, wherein the sponge may be disposed around the drill bit to extend along an axis of the drill bit, such that a head of the drill bit and/or a shank of the drill bit may project from the sponge.

According to a second aspect of the present invention, there is provided a method of cooling a drill bit when in use, the method comprising the steps of: providing an open-cell foam sponge configured to absorb water into which it is placed; placing the sponge in water; attaching the sponge to the drill bit such that the sponge substantially surrounds the drill bit; and actuating the drill bit to drill into a surface, such that as the drill bit moves into the surface the sponge is compressed by the surface such that water is expelled from the sponge.

The sponge may be pre-soaked in water (preferably cold water); however, in preferred embodiments, the sponge is introduced to a vessel of water after the sponge has been attached to the drill bit.

The operator may push the sponge rearward into the cup/holder, and then may release the sponge, thereby allowing the sponge to reasserts itself. This step may be carried out only once or a plurality of times, to ensure that the sponge is saturated.

During drilling, the sponge may be replenished with water to suit the operation, without removing the sponge from the drill bit.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a cross section through a first drill bit cooling device coupled to a drill bit.

Figure 2 shows the first drill bit cooling device coupled to a drill bit including a hole cutter.

Figure 3 shows a second drill bit cooling device coupled to a drill bit having only a hole cutter.

Figure 4 shows a third drill bit cooling device coupled to a drill bit including a hole cutter.

The present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term “comprising”, used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression “a device comprising means A and B” should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

Reference throughout this specification to “an embodiment” or “an aspect” means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases “in one embodiment”, “in an embodiment”, or “in an aspect” in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the description provided herein, numerous specific details are set forth. Flowever, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The use of the term “at least one” may mean only one in certain circumstances.

The principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

Figure 1 is a schematic representation of a cross section through a first drill bit cooling device coupled to conventional drill bit. For instance, the drill bit may be a twist drill bit comprising a pointed tip 1 axially disposed on a cylindrical shaft 3 with helical flutes (not shown) disposed thereon. Alternatively, the drill bit may be a ceramic tile drill bit having a pointed cutting tip 1 disposed on a cylindrical shaft 3, often shaped like an arrow head, but with the details not shown in the figures for clarity.

The device comprises an annular sponge that surrounds the drill bit, and extends along the shaft 3 with one end substantially adjacent to the tip 1. The sponge is held in position by an annular cup 7 into which the sponge is received. The cup 7 may be (e.g. securely) attached to the shaft 3 by any conventional means, such as by screw, clamp, glue, etc.

The sponge 5 is shaped to taper at the end adjacent to the tip 1.

Figure 2 shows a similar view to that of figure 1, but with the device coupled to a drill bit that further comprises a hole cutter 9 axially disposed on the shaft 3, such that its cutting edge is axially aligned, yet spaced from the tip 1. To fit around the hole cutter 9, the sponge 5 is radially compressed from the interior by the hole cutter 9.

Figure 3 shows a further similar view to that of figure 1, but with a further modified drill bit comprising the hole cutter 9 and shaft 3, but without the tip 1. Furthermore, to avoid unnecessary compression of the sponge 5 by the hole cutter 9 (thereby limiting the amount of water that may be absorbed), an further sponge 15 having a larger internal diameter is used within the cup 7.

Figure 4 shows a view of a still further modified device coupled to the drill bit shown in figure 2 in use during drilling into a surface 31. In this arrangement, the sponge 15 with the larger interior diameter is used within a modified cup 17 having an interior wall for gripping the interior of the sponge 15 that is spaced from the shaft 3. In particular, a spacer 21 is included between the shaft 3 and the sponge 15 such that the cup 17 may grip the sponge 15 on its exterior and interior sides.

As the tip 1 and hole cutter 9 drill a hole in the surface 31, the sponge 15 is compressed in a direction parallel to the drill bit axis (i.e. parallel to the shaft 3) such that water is expelled from the sponge 15 which may act to cool the drill bit, and in particular the hole cutter 9.

Claims (7)

1. A drill bit cooling device, for use with a drill bit of a power tool, the device comprising: an open-cell foam sponge configured to absorb water into which it is placed; and means for attaching the sponge to the drill bit such that the sponge substantially surrounds the drill bit.

2. The drill bit cooling device of claim 1, wherein the sponge is attachable to the drill bit at an end of the sponge distal from the drill bit head.

3. The drill bit cooling device of claim 1 or claim 2, wherein the means for attaching the sponge to the drill bit is a coupling disposed on the sponge at one end of the sponge.

4. The drill bit cooling device of claim 3, wherein the coupling comprises an annular cup into which the sponge is received.

5. The drill bit cooling device of any preceding claim, further comprising a drill bit, wherein the sponge is disposed around the drill bit to extend along an axis of the drill bit, such that a head of the drill bit and a shank of the drill bit project from the sponge.

6. A method of cooling a drill bit when in use, the method comprising the steps of: providing an open-cell foam sponge configured to absorb water into which it is placed; placing the sponge in water; attaching the sponge to the drill bit such that the sponge substantially surrounds the drill bit; and actuating the drill bit to drill into a surface, such that as the drill bit moves into the surface the sponge is compressed by the surface such that water is expelled from the sponge.

7. A drill bit cooling device substantially as hereinbefore described with reference to the accompanying drawings.