The creation of a recess in an edge of the door, for example to create a mortise lock in the door, is a very fine process and involves precision drilling to create recesses in the correct and exact location. Without suitable industrial-sized equipment, a carpenter or every day person attempting do-it-yourself is often left to resort to the use of a hammer and chisel to create the recess, or often ends up having to drill multiple apertures through the edge of the door before the correct alignment of the recess is achieved.

Routers are commonly used to provide precision joinery in wood but the movement of the cutter in relation to the router jig is limited and therefore a router can often not achieve the precision required.

The present invention seeks to alleviate the aforementioned disadvantages by providing a portable drill assembly that is able to provide accurate and precision drilling.

According to one aspect of the present invention, there is provided a drill assembly comprising preferably elongate, substantially parallel clamp members for clamping a workpiece therebetween, a longitudinal guide member extending along at least part of the length of at least one clamp member, a transverse guide member mounted on the longitudinal guide member and extending between said clamp members in a generally transverse direction to the first guide member, and a drill housing mounted on said transverse guide member, the housing thereby being movable in the direction of the longitudinal axis of the clamp members and in a direction generally transverse thereto, whereby the position of the drill housing is adjustable in two dimensions with respect to the workpiece.

Preferably a longitudinal guide member extends along at least part of the length of each clamp member.

Preferably still, the assembly comprises two transverse guide members mounted on said longitudinal guide members and extending between the clamp members in a generally transverse direction to the longitudinal guide members.

The drill housing is preferably mounted on and extends between the transverse guide members.

Advantageously, the drill assembly further comprises a platform attached to and extending between the transverse guide members and the drill housing being located on said platform.

The ends of the platform preferably form transverse carriage slides slidable along part of each transverse guide member.

One or each of the transverse carriage slides may include a locking member for locking the or each carriage slide in a fixed position along the transverse guide members.

The ends of the transverse guide members may be linked to longitudinal carriage slides which are slidable along at least part of the length of each longitudinal guide member.

Preferably, one or each of the longitudinal carriage slides includes a locking member for locking the or each carriage slide in a fixed position along the associated longitudinal guide member.

The drill assembly may comprising limitation means to limit the distance the transverse carriage slide members can slide along the transverse guide members.

The limitation means may limit movement of the transverse carriage slides within a generally mid-portion of the transverse guide members.

Advantageously, the or each transverse guide member has a measurement scale along at least part of its length.

Preferably still, the or each transverse carriage slide includes a measurement scale extending along at least part of its length.

The measurement scale on the transverse guide member preferably has a zero marker at its mid-point and extends in each direction in equal positive increments.

The or each transverse carriage slide may include a guide rail extending along at least part of its length, and including a pointer slidable along said guide rail to point to a position on the measurement scale of the or each transverse carriage slide and the or each transverse guide member.

In a preferred embodiment, the clamp members have a plurality of apertures and/or recesses formed in each clamping member to allow clamping blocks to be attached thereto such that an object can be clamped between said clamping blocks.

Preferably still, the clamp members have at least one aperture/recess formed on the bottom surface of each clamping member to allow a stand, or legs to be attached thereto to extend downwardly therefrom.

Advantageously, the drill housing comprises a drill bit encased in a drill casing.

The drill bit may comprise a drill head located at one end of a drill stem.

The drill bit may comprise a milling portion, and both the milling portion and drill head may have a plurality of outwardly extending lateral blades.

Preferably, the drill head has a plurality of apertures extending longitudinally through the drill head.

The drill stem may further includes a handle extending laterally therefrom for vertical movement to the drill stem and the drill casing may include a longitudinal opening in two of its opposing sides through which the handle protrudes.

The outer surface of the casing, along the length of each opening, is preferably provided with a measurement scale.

Advantageously, the drill head is pivotally mounted on the stem.

According to a second aspect of the present invention, there is provided, a drill bit having at least one aperture formed in an end surface and extending along at least part of the length of the drill tool.

According to a third aspect of the present-invention, there is provided drill bit comprising a stem on which is located a head portion and a milling portion, the head portion having at least one aperture formed in its end surface and extending along at least part of the length of the drill head.

The present invention provides precision drilling that is particularly beneficial when being used for creating a door lock, but finds other applications.

One embodiment of the present invention will now be described, by way of example, with reference to the accompanying figures, in which : Figure 1 is a perspective view of a drill assembly, constructed in accordance with the present invention, with the drill housing removed ; Figure 2 is an end view of the drill assembly of Figure 1.

Figure 3 is a side view of the drill assembly of Figures 1 and 2 including the drill housing ;

Figure 4 is a perspective view of the drill assembly of Figures 3 with the casing of the drill housing removed; Figure 5 is a perspective view from below of the drill assembly of Figure 4; Figure 6 is a perspective view of legs that can be attached to the guide assembly constructed in accordance with the present invention; and Figure 7 is a magnified view of the transverse guide member of Figure 3; Figure 8 is a magnified view of the longitudinal guide member of Figure 3; and Figure 9 is a perspective view of a drilling bit of a drilling tool constructed in accordance with the present invention.

Referring first to Figures 1 and 2, the drill assembly comprises first and second elongate clamp members 10,12 substantially of L-section that are spaced apart and extend are located substantially parallel to and facing away from one another. A small rebate 13 is formed at the top of each in the inwardly facing surface of the each clamp member 10, 12. The rebate. 13 prevents the top surface of an object positioned between the clamp members 10,12 from extending beyond the top of the clamping members. Although not shown in the Figures, the first clamp member 10 may have measurement scale so that an object to be clamped between the clamp members 10, 12 can be aligned to a specific position. In this case a guide block (also not shown can be positioned at the zero position of the measurement scale to prevent the object from moving from its aligned position.

Each clamp member 10,12 has a longitudinal guide member 14,16 attached to and extending along the outwardly facing surface of its clamp member 10,12. Only the guide member 14 of the first clamp member 10 can be seen in Figure 1. The guide member 14 is described in detail with reference to Figure 8.-

longitudinal guide members 14,16 of the each clamp member 10,12 respectively. The carriage slides 22,24 are described in detail with reference to Figure 8.

The second carriage slide 24 associated with the second clamp member 12 has a locking device in the form of a rotatable handle 26 which can be manually turned to lock the carriage slide 24 at a pre-determined position along the longitudinal guide member 16 of the second clamp member 12 to prevent further movement of the carriage slide 24, and thus the transverse guide members 18,20, along the longitudinal guide member 16. Activation of the locking device 26 also prevents movement of the first carriage slide 22 along the first longitudinal guide member 14 due the fact that the transverse guide members 18,20 are attached at their ends to both first and second carriage slides 22,24.

A platform 28 extends between the first and second transverse guide members 18,20 at a substantially mid-portion thereof. The platform provides a base on which can be located a drill assembly housing 30 (see Figure 3).

The edges of the platform 28 extend over and around part of the guide members 18,20 forming third and fourth carriage slides 32,34 slidable along part of the length of each transverse guide member 18,20.

The second transverse guide member 20 has stop blocks 36 (only one of which can be seen in Figure 1) located around the guide member 20 on either side of the fourth carriage slide 34 to limit the distance that the fourth carriage slide 34 can travel along the length of the guide. member 18 in both directions (and hence the distance the distance that the third carriage slide 32 can travel along the length of the second transverse guide member 20). Consequently, the platform 28, though being slidable to some extent along the first and second transverse guide members 18,20, remains within the substantially mid portion of the guide members 18,20, between the clamp members 10,12. The stop blocks 36 have levers 38 to release them and thus to adjust their location along the second guide member 20.

some extent along the first and second transverse guide members 18,20, remains within the substantially mid portion of the guide members 18,20, between the clamp members 10,12. The stop blocks 36 have levers 38 to release them and thus to adjust their location along the second guide member 20.

The third carriage slide 32 associated with the first transverse guide member 18 has a locking device in the form of a rotatable handle 40 which can be manually turned to lock the carriage slide 32 at a pre-determined position along the guide member 18 of the to prevent further movement of the carriage slide 32, and thus the platform 28 along the guide member 18. Activation of the locking device 40 also prevents movement of the fourth carriage slide 34 along the second transverse guide member 20.

The first carriage slide 22 is slidable along the first guide member 14 of the first clamp member 10 manually by a handle 42 which activates a cog mechanism 44 located on the outer surface of the first clamp member 10. The cog 44, in turn, drives a belt 46 to move the slidable carriage 22 along the guide member 14.

Due to the association of all the connecting parts, movement of the carriage 22 along the guide member 14 causes movement of the transverse guide members 18,20 and thus the platform 28 located therebetween in the same direction along the first and second guide members 22,24.

The first longitudinal guide member 14 also has stop blocks 48 located around the guide member 14 on either side of the first carriage slide 22 to limit the distance that the carriage slide 22 can travel along the length of the guide member 14 in both directions (and hence the distance the distance that the second carriage slide 24 can travel along the length of the second longitudinal guide member 16).

The stop blocks 48 have levers 50 to release them and thus to adjust their location along the first longitudinal guide member 14.

In an alternative embodiment (not shown), movement of the first carriage slide 22 along the first guide member 14 of the first clamp member 10 is controlled automatically by a computer processor.

Referring now additionally to Figure 3, the drill housing 30 is located on the platform 28 by the provision of four positioning members 52, at each of the four corners of the platform 28. The drill housing 30 is located over the positioning members 52 and is pushed down over them to snap into place. The drill housing 30 is released from the positioning members via buttons (not shown) located in each corner of the drill housing 30.

Once located over the positioning members, the drill housing is slidable between a set distance along the first and second transverse guide members 18, 20 by means of the platform 28. Movement of the second and third carriage slides 32, 34, and thus of the platform 28, is controlled by a motor 54 linked to the third carriage slide 32.

The drill housing 30 has an outer casing surrounding a drilling tool and associated movement mechanism. The outer casing has a longitudinal opening 60 in two of its opposing sides (only one of which can be seen in Figure 3). A handle 62, forming part of the drilling tool movement mechanism protrudes outwardly from the openings 60 in the outer casing 56 of the drill housing 30. As can be seen in Figure 4, the handle is directly attached a stem 64 of a drill bit 58 so to provide upward and downward movement thereof.

The outer surface of the casing 56 is provided, along the length of each opening 60, with a measuring scale 66 which allows a user to move the drill assembly handle 62 and thus the drill bit 58 downwardly (and upwardly) a precise distance and to a precise location. As such, the user is able to read the measuring scale 66 to know precisely how far the drill bit 58 extends from the bottom of the housing and into the gap between the first and second clamp members 10,12. Accordingly, an aperture of a precise depth can be drilled into an object (for example a wooden door) that is clamped between the clamp members 10,12.

A locking member 68 is also provided to prevent downward movement of the drill bit 58 past a pre-determined position on the measurement scale 66.

The drilling tool has two vertical rails 69 extending parallel to and along at least part of the length of the drill bit 58. The drill bit 58 is linked to the vertical rails 69 and is releasable therefrom by a button (not shown). The drill bit 58 includes a spring mechanism (not shown) and a dented guide (also not shown). The dented guide has intervals of 2 mil equating to drilling depths of 2 to 3 mm. The guide emits a clicking sound due to the dents upon each increment to aid the user in determining the precise distance of the downward movement of the drill bit 58. This allows the drill bit 58 to be moved upwardly and downwardly fairly quickly while maintaining the accuracy of the depth. As such, the apparatus has a particular use in carpentry. The precise control of depth of the drill bit 58 means that the apparatus can be used for any number of processes, such as mortising, tanging, grooving, beveling, chamfering or filleting according to the design of the jig attached to the drill housing 30.

Downward and upward movement of the drill bit 58 can be alternatively controlled by a motor provided, for example, in the top portion 70 of the drill housing 30. Movement of the drilling tool 58 can be automatically controlled by a computer.

In an alternative embodiment (not shown) the drill bit 58 is pivotally mounted within the movement mechanism such that the drill bit 58 can enter an object clamped between the clamp members 10,12 at an angle inclined to a pre-determined degrees from vertical Referring now to Figure 5, the clamp members 10,12 have a plurality of apertures 72 formed at predetermined locations on their inner, facing clamping surfaces. Clamping blocks (not shown) can be attached to the inner clamping surfaces of the clamping members at any or all of the locations in which the apertures are present. The presence of clamping blocks allows for a gap between the clamping members 10,12 to be maintained when an object to be drilled is clamped between the clamping blocks. This

extends the limits to where the drill bit 58 can be positioned and thus where an aperture can drilled into the object.

The clamping members 10,12 have a recess and apertures 74 formed in their bottom surfaces. Using such a recess with apertures 74, a stand or legs 76, such as can be seen, for example, in Figure 6, can be attached to the bottom of the clamping members 10,12 to allow the entire apparatus to stand freely in use.

Figure 7 shows a magnified view of the fourth sliding carriage 34 and second transverse guide member 20. A measurement scale 78 is provided on the outer surface of the guide member 20. The sliding carriage 32 also has a measurement scale 80 provided on its surface. The measurement scale 80 of the sliding carriage has a zero marker at its mid-point and continues in each direction from the zero marker in equal positive increments. The sliding carriage 32 has a guide rail 82 along its length on which is slidably located a pointer 84. The pointer 84 is able to slide along the guide rail 82 of the sliding carriage 32 which, in turn, slides along the guide member 20 such that the pointer 84 can provide a measurement to the user from both the measurement scale 80 of the sliding carriage and the measurement scale 78 of the guide member 20.

The guide rail 82 has a locking device in the form of a rotatable handle 86 which can be manually turned to lock the pointer 84 at a pre-determined position along the guide rail 82 to prevent further movement.

Accordingly, the precise location of the drill housing 30 and drill bit 58 can be determined and thus an aperture can be drilled into an object clamped between the clamping members 10,12 accurately at the required position.

Figure 8 shows the sliding mechanism of the sliding carriages 22,24 and the longitudinal guide members 14,16. The longitudinal guide members 14,16 are of generally cylindrical configuration having four longitudinal grooves 86 formed in the external surface. The grooves 86 are designed to receive and guide a plurality of ball bearings 88 along part of the length of the guide members 14,16. The slide carriages

22,24 comprise two longitudinal outer parts 90 located on either side of an inner part 92. Both the outer parts 90 and the inner part 92 have apertures 94 therethrough to receive the associated guide member 14,16. The inner surface of the outer parts 90 and inner part 94 have complementary grooves 96 to receive ball bearings 88 in the grooves 86 of the associated guide member 14,16 and the. The outer parts 90 have an extension 98 through which a further aperture 100 is formed and through which a electrical wire or cable (not shown) can be threaded to provide automated control of the sliding carriage 22,24 along the guide member 14,16. The inner section 92 of the sliding carriage has an aperture to receive a screw 102 to lock the sliding carriage 22, 24 in a pre-determined position along the guide member 14,16.

-A magnified representation of the drill bit 58 is shown in Figure 9. The drill bit 58 has a drill head 110 and a milling portion 112. Both the drill head 110 and milling portion 112 are formed on the stem 64. The drill bit 58 is attached to the rest of the drill assembly via a hexagonal grip portion 114 above the milling portion 112.

Both the drill head 110 and milling portion 112 have radial blades 116 extending from their outer surface. The blades provide chaffing to the sides of an aperture drilled in a object clamped between the clamping members 10,12.

The milling portion 112 comprises an outwardly directed cylindrical flange 118 extending from the stem 64 of the drill bit 58. The milling portion 112 forms an enlarged rebate at the entrance to an aperture formed by the drill bit 58.

The drill head 110 has a plurality of apertures 120 extending longitudinally through the drill head 110. The presence of such apertures allows for heat produced during drilling to dissipate away so to avoid localised burning of the object around the drill head 110 during use which affects the quality of the resulting Aperture.

In. an alternative embodiment (not shown in the figures !. the clamp members incorporate rolling members to allow the clamp members to roll along the object to be drilled so to locate the clamp members in precise positions along the object. The rolling members may comprise, for example a plurality of cylindrical elements, each element extending across the width of the clamp members.