Object of the Invention

This invention relates generally to a drilling device for creating mounting holes in a body, wherein the body is timber, plaster, cement, hard insulation or a similar material, such that the body can be easily and safely be bonded to another such body.

Background to the Invention

Casting is a manufacturing process in which a liquid material is poured into a mould which contains a hollow cavity of the desired shape. The liquid material then solidifies and this solidified piece (also known as the cast) is ejected or broken out of the mould to complete the process. Casting is often used for making complex shapes that would otherwise be difficult or uneconomical to make by other methods. A wide variety of materials are suitable for casting including metals or various time setting materials (such as epoxy, concrete, clay, plaster etc.) which cure after mixing two or more components together.

Once the casts are prepared, they can be bonded or mounted on to walls or ceilings through high-end joinery processes which involve joining together pieces of wood, timber, hard insulation or concrete casts using fasteners or adhesives, or both, followed by bonding these joined pieces on to walls or ceilings. It is possible to screw or fix these fasteners through the visible face of the plaster or concrete creations but this would require a repair patch afterwards in order to hide the hole which was made on the visible face of the creation. The patching process may require a lot of time and the patch may remain visible after it has been completed.

Typically, pins or dowels are employed for the purpose of joining timber pieces or joining plaster casts to plasterboard. Finished (varnished and unpainted) timber pieces are glued together using adhesives and fixed through pins or dowels. However, one disadvantage of fixing timber pieces or plasterboard through pins or dowels is that they may be visible on face of the finished piece and they may need to be patched.

For joining and mounting concrete pieces, typically, a hole must be drilled in the surface (or surfaces) of the body to be mounted. A metal rod can then be inserted into the hole and secured in the hole through means of an adhesive. This fixing means is subject to several disadvantages, primarily, the drilled hole must be fully emptied of dust and drilling residues before the adhesive is injected into the hole. If the hole is not fully cleaned prior to application of the adhesive, the adhesive may not correctly adhere to the surrounding concrete hole. Similarly, if the material in which the hole is made is not very well compacted, this may be subject to crumbling which would have the same effect as a hole which has not been adequately cleaned. If the adhesive does not adhere to the surrounding surface of the hole and a force is applied to the metal bar which is set in the adhesive, it is possible that both the bar and the adhesive may be pulled out of the hole completely. As this means of fixation is often used for large and heavy plaster or concrete architectural pieces, such as for example cornices, the force being applied to the metal bar through the weight of the attached piece may be large enough to exert a substantial tensile force on the metal bar. As these features are often located at a height or on a ceiling, it is particularly important that the mounting means does not fail for safety reasons.

It is therefore an object of the present invention to advance the technology for mounting items such as plaster, timber, concrete or hard insulation and to avoid the shortcomings of the prior art.

Summary of the Invention

According to a first aspect of the invention, there is provided a drilling device for drilling a mounting hole into a body, wherein the mounting hole is employed for bonding or mounting the body in a secure manner, the device comprising;

- an outer body;

- a cross bar;

- a main bar comprising a hole through which the cross bar extends;

- a drill means for rotating the main bar; - a guide hole in the outer body through which the main bar extends;

- a set of blades each comprising a proximal end and a distal end;

- a fixation means which rotationally fixes an intermediate point between the proximal end and distal end of each of the blades to the main bar; and

- a spring means which biases the proximal ends of the blades towards each other wherein the drill means rotates, moving the main bar and each of the components which are attached to it towards the surface of the body, as the blades penetrate the surface of the body and drill into the body, the proximal ends of the blades are pushed apart by the cross bar and the distal ends of the blades rotate away from each other, such that the diameter of the cutting circle inscribed by the rotating blades is directly proportional to the depth of the blades within the body.

Preferably, the drill means is electrically powered by a cordless drill or an impact driver or a manufacturing line assembly station.

Preferably, the material in which the mounting hole is drilled is composed of plaster, concrete, timber, hard insulation or a similar material.

Preferably, the shape, angle and position of the blades within the device are adjustable based on the requirements of the body such that each mounting hole size is specific to each body.

Preferably, the device further comprises a depth gauge such that calibration of the depth gauge for each body ensures that the shape and size of the mounting hole is sufficient to prevent adhesive from escaping from the mounting hole.

Preferably, the vertical axes of the blades are parallel to the vertical axis of the main bar. In a second embodiment of the invention, preferably the cross bar comprises cross bar slots such that the blades are positioned to pass through the cross bar slots thus increasing the robustness of the blades as they rotate due to their contact with the cross bar slots.

Brief Description of the Drawings

The present invention will now be described, by way of example, with reference to the accompanying drawings in which:

Figure 1 illustrates a front elevation view of a drilling device according to the present invention wherein portions of an outer body are not shown for visual clarity;

Figure 2 illustrates a perspective view of the drilling device of Figure 1 ;

Figures 3 illustrates an elevation view of a set of blades of the drilling device of the present invention as they initially contact the surface of the material to be cut;

Figure 4 illustrates an elevation view of the set of blades of Figure 3 wherein distal ends of the blades begin to separate from each other due to a compressive force being applied to the drilling device;

Figure 5 illustrates an elevation view of the set of blades of Figure 3 and 4 wherein the distal ends of the blades continue to separate from each other due to the compressive force being applied to the drilling device;

Figure 6 illustrates an elevation view of the set of blades of Figure 3, 4 and 5 wherein the blades are in their final drilling position;

Figure 7 illustrates elevation views of examples of alternative blade shapes;

Figure 8 illustrates an embodiment of the invention wherein the main bar comprises a drill bit; and Fig 9 illustrates an embodiment of the invention where cross bar slots are provided in order to facilitate a new blade position wherein the blades passe through the cross bar slots.

Detailed Description

Referring now to the accompanying drawings, there is illustrated a first embodiment of a drilling device, generally indicated as 10, which allows a user to create a mounting hole which is used to bond or mount pieces of cast plaster, timber, concrete, hard insulation or other materials together in a secure manner, and in particular, to bond or mount plaster casts, timber, concrete, hard insulation or other materials onto walls or ceilings in a secure manner.

Figure 1 illustrates the general layout of the components of the device (10) and Figure 2 illustrates a perspective view of these components. The device (10) comprises various components which are at least partially located within a substantially cylindrically shaped outer body (1 1 ). The outer body (11 ) maintains the alignment of the device (10) in use. The device (10) comprises a drill means (A). The drill means (A) can be powered by hand or it can be connected to an external power supply (for example an electric screwdriver or a powered rotating unit on a manufacturing line). The drill means (A) must be capable of rotating, however, in some situations it may also be subject to a hammer action or an impacting force, such as, for example that of an impact driver tool or a hammer action tool - wherein both a rotating and a hammering or impacting force are exerted on the drill means (A).

The device (10) also comprises a main bar (H) which is connected to the drill means (A) such that rotation of the drill means (A) causes rotation in the main bar (H). A guide hole (C) is provided in the outer body (11 ) such that the main bar (H) passes through the outer body (11 ). Thus, one end of the main bar (H) is connected to the drill means (A) and the other end of the main bar (H) comprises a rotational fixing point for a set of blades (D). The main bar (H) also comprises a hole (F) through which a cross bar (G) is positioned. The cross bar (G) comprises a primary bar with two feet which are fixed at each end of the primary bar. The feet may comprise wheels at their unfixed ends. The feet may be in the form of a bars which are fixed at a perpendicular angle to the primary bar. When the drill means (A) is rotated, the cross bar (G) is also forced to rotate due to its contact with the main bar (H). The cross bar (G) limits the sliding motion of the main bar (H) to a sliding length which is defined by the longitudinal length of the hole (F). Once the cross bar (G) reaches the end of the sliding length, the main bar (H) is no longer able to advance further in that direction.

The set of blades (D), also referred to herein as blades (D), are rotatably fixed to the main bar (H) at their distal ends through the rotational fixing point. The blades (D) must generally be formed such that, in use, when they are placed in opposition to each other as shown in Figures 1 - 6, they comprise at least two overlapping areas. One area of overlap allows a single pin to traverse through both blades in order to create a fixing point which allows the blades (D) to rotate in one plane and one area of overlap which allows the blades (D) to cross over each other thus defining a closed space between the blades (D). It will be appreciated that whilst Figures 1 - 6 disclose blades (D) which are approximately V shaped, a number of variations in the shapes of blades (D) are possible whilst remaining within the scope of the invention. Examples of variations in the shape of the blades (D) have been illustrated in Figure 7. It will be appreciated that the invention is not limited to these shapes of blades (D). The blades (D) may be removed from the device (10) and replaced with another set of blades (D). The blades (D) may be removed and replaced by an identical set of blades (D) (for example if the first set of blades (D) is damaged or worn out) or the blades (D) may be removed and replaced by blades (D) of a different shape, for example when the device (10) is being used to drill into bodies (K) of different types of materials. The need for different blades (D) for bodies (K) which are composed of different materials can be seen when plasterboard is compared to concrete. For example, plasterboard is typically very thin (for example, it may have a standard thickness of 12.5mm). When the device (10) is used to drill into plasterboard, a sharp cutting angle is required in order for the mounting hole to be of a size where it can be effective. Thus, the mounting hole in plasterboard will have an apex with a wide angle. Conversely, when the device (10) is used to drill into concrete, a shallow cutting angle is required in order to create a deeper reverse cone shaped mounting hole. Thus, the mounting hole in concrete will have an apex with a narrow angle. The mounting hole for a concrete piece may typically be at least 150mm in depth. Due to the relative hardness of concrete when compared to plaster or wood, it may be necessary to additionally support the blades (D) for concrete applications. In this embodiment, the main bar (H) also comprises a drill bit at its distal end such that the main bar (H) also drills into the body (K) when it is rotated, thus substantially removing the pressure on the blades (D). The embodiment wherein the main bar (H) additionally comprises a drill bit at its distal end is illustrated in Figure 8. As illustrated in Figure 9, additional support may be provided for the blades (D) in that the blades (D) can pass through the cross bar (G) in additionally provided cross bar slots (13). The configuration where the blades (D) pass through the cross bar (G) means that the blades (D) are free to slide up and down within the cross bar slots (13) and the blades (D) are also rotationally fixed to the main bar (H) at their distal ends and elastically connected to each other at their proximal ends. In this embodiment the rotational fixation point of the blades (D) is positioned to coincide with the new location of the blades (D) within the cross bar slots (13).

The main bar (H) also comprises a depth gauge (B), such that, in use the main body (H) is prohibited from extending beyond a certain predefined length from its original position. The depth gauge (B) may be adjustable such that the predefined length can be manually changed for different situations (such as but not limited to in instances wherein the device (10) is used to drill into different materials (K) or the shape of the pieces to be drill requires specific attention). Thinner materials (such as for example plasterboard) may require a shallower cut than thicker material such as wood. Thus, the ability to gauge the depth and limit the cutting diameter of the blades (D) accordingly provides a distinct advantage and results in a more versatile device (10).

The device (10) also comprises a spring means (E) such that the proximal ends of the set of blades (D) are elastically connected through the spring means (E). The spring means (E) is fixed to each of the blades in tension, the proximal ends of the blades (D) are bias to move towards each in the absence of any other exerted force on the blades (D). It will be appreciated that the spring means (E) could be achieved in a variety of different ways whilst providing the desired result of biasing the proximal ends of the blades (D) towards each other in the absence of any other external force. The spring means (E) embodiment shown in Figure 2 is for exemplary reference only. In addition, it is not necessary that the spring means (E) holds the blades (D) in tension, another setup could be arranged such that the spring means (E) is connected to a different side of the blades (D) and the spring means (E) would then hold the blades (D) in compression whilst still biasing the proximal ends of the blades (D) towards each other.

In use, the drill means (A) is rotated, which rotates the cross bar (G) due to its location within the hole (F) for the cross bar. As the crossbar (G) rotates, the blades (D) also rotate (due to their position on either side of the main bar (H) and the cross bar (G) being contained within the space defined between the blades (D)). As a compressive force is additionally exerted on the device (10), the main bar (H) advances toward the body (K). As the main bar (H) advances towards the body (K), the cross bar (G) maintains its position relative to the outer body (11 ) and the proximal ends of the blades (D) (which are held in tension through a spring means (E)) begin to move away from each other. The motion of the proximal ends of the blades (D) moving away from each other, causes the distal ends of the blades (D) (which are rotationally fixed) to rotate away from each other, thus widening the cutting diameter of the blades (D). The continuous exertion of a compressive force on the device (10) while the drill means (A) is rotated means that the distal ends of the blades (D) continue to move apart. Thus, the deeper the device (10) advances into the body (K), the wider the cutting circumference of the blades (D). The diameter of the mounting hole thus drilled is directly proportional to its depth, i.e., as the hole gets deeper, its diameter increases, resulting advantageously in a reverse V-shaped or wedge-shaped hole. The device (10) can continue to advance into the body (K) until the depth gauge (B) prevents the device (10) from advancing into the body (K). As the device (10) is retracted away from the body (K), the spring means (E) ensures that the proximal ends (and thus due to the geometry of the blades (D) and the fixation point, the distal ends of the blades (D)) are brought together, thus allowing the device (10) to be retracted from the material without causing interference to the mounting hole which has been created.

Figure 3 illustrates the main bar (H) in its initial position. The distal ends of the blades (D) are located on the surface of the body to be cut (K). Figure 4 illustrates the blades (D) as they advance into the body (K). In order to achieve this position, the main bar (H) has advanced in the direction of the body (K) thus pushing the blades (D) into the body (K). The mounting hole created by the blades (D) is beginning to take the form of a reverse cone shape.

Figure 5 illustrates a further stage of the cutting process wherein the main bar (H) has continued to advance towards the body (K) and the blades (D) have continued to advance further into the body (K). The mounting hole has now taken on a more pronounced and deeper reverse cone shape.

Figure 6 illustrates a final stage of the cutting process wherein the main bar (H) has continued to advance further in the direction of the body (K) and the blades (D) have continue to advance into the body (K). The cross bar (G) is now limited by the hole (F) so the device (10) cannot advance any further into the body (K).

It will be appreciated that the shape of the blades (D) and of the mounting hole, depth of penetration of the blades (D) and limiting effect of the cross bar (G) which are illustrated in Figures 3 - 6 are for exemplary purposes only and the inventive concept of the device (10) is not limited solely to the parameters, scale or configuration shown in the figures.

The device (10) is used to drill a mounting hole in a body (K) such as plaster (for example plasterboard or cast pieces of plaster), timber, concrete, hard insulation (for example Kingspan ®) or other suitable material. Due to the unique structure of the device (10), and in particular the shape and arrangement of the blades (D) relative to the other components of the device (10), as the device (10) is rotated and a force is exerted on the device (10), the device drills a hole into the target surface of the body (K). As the device (10) advances into the body (K), the distal ends of the blades (D) cut into the body (K) thus creating a mounting hole. As the device (10) continues to advance into the body (K), the cutting radius defined by the distal ends of the blades (D) increases such that the resulting mounting hole generally resembles a reverse cone as shown in Figure 4, 5 and 6. Once the mounting hole has been created, a rod and adhesive are place in the mounting hole, per standard mounting practises. The adhesive hardens around the rod thus creating a solid cone shape with a rod extending out of the apex of the cone. As this cone of adhesive is within the body (K) and protrudes from within the material to the outer surface of the body (K) in what is known as a reverse cone configuration, it is not possible to remove the cone without also removing a substantial amount of material of the body (K) from around the cone. The cone and rod are thus firmly embedding in the body (K). This method can also be used to create a second mounting hole another body (to which the first body (K) will be joined) and one single rod can be shared between both mounting holes thus firmly embedding this single rod in two reverse cone of adhesive which are firmly set into their respective materials. Alternatively, a screw, or other member, may already be protruding from an object, in which case the mounting hole can simply be filled with adhesive and the body can be positioned such that the screw or other member is at least partially positioned within the mounting hole, such that the adhesive in the mounting hole sets around the screw, or other member, thus securely fixing the body to the screw or other member.

It is to be understood that the invention is not limited to the specific details described herein, which are given by way of representations and examples only and various modifications and alterations are possible without departing from the scope of the invention as defined in the appended claims.

Taking into consideration the aforesaid disadvantages of the prior art, the drilling device (10) according to the invention alleviates these shortcomings and provides a novel means of joining and mounting cast pieces, timber, plaster, hard insulation or concrete by radially expanding the cutting blades (D) of the device (10) as the device (10) drills inside body (K) until a desired depth of mounting holes is achieved, thereby providing a V-shaped or reverse cone shaped mounting hole. The distinct shape of the mounting hole prevents the adhesive and the rod (which may be metal - for example a standard reinforcement bar) from being pulled out of the body (K), even if the adhesive has not fully adhered to the body (K). In addition, the device (10) and resulting mounting hole eliminates the need to secure cast pieces, timber, plasterboard or concrete with the help of pins or dowels thus enhancing the aesthetic appeal of the mounted pieces.