The present invention concerns the machining of a workpiece using a normally hand held type power drill and the assistance of a clamping table. In particular the invention concerns the incorporating of the clamping function of the jaws to provide a firmer more controlled operation in the machining of a workpiece.

The apparatus for mounting a normally hand held type power drill, be it a standard size DIY drill or a more compact Dremel™ type drill, may generally be divided into two types: a drill press which holds the drill at a point adjacent to the chuck which we may call its neck and which guides the drill vertically down a single or twin column to a base where the workpiece is positioned; and a multi-angle drill holder which again is attached to the neck of the power drill but holds the drill in a fixed but multi-angled adjustable position above the surface to which the apparatus is attached.

Both types of apparatus may be fixed to the jaws of a clamping table by means of an incorporated clamping element or by means of a separate G-clamp for example. In neither case does the displacement function of the jaws of the clamping table play a part in the operating of the drill press or the multi-angle drill holder; both may be equally well attached to a kitchen table for example and still perform their essential function.

Of the multi-angled drill holder it may be said that, while it may adjust the angle of the drill, it is normally at a level too high above the surface supporting the apparatus for the workpiece to receive any support from that surface. Effectively this means that the workpiece is simply hand held in thin air and fed to, for example, a sanding disk or stone fitted to the power drill.

The drill press works adequately in vertically drilling a workpiece but in its conventional embodiments it is limited in scope. The Dremel Work Station™ which proposes a drill press which the drill can be displaced in an angled and horizontal plane as well as a vertical plane does not provide any means whereby, in horizontal plane for example, the workpiece can be supported and held before or while being presented to the drill. In this horizontal plane, the closest the drill can be to the support surface is some 10.5 cm (4 inches) and so the surface cannot provide support or guidance for any but the largest of workpieces.

The free hand approach of presenting a workpiece to a fixed power drill may be adequate for the purposes of sanding or polishing for example. However, for accurate working such as drilling holes, it is far preferable that not only should the power drill be firmly fixed or guided by a suitable apparatus but also that the workpiece should be supported by a solid surface and where necessary guided by elements attached to that surface.

In US 7316250, a drill is mounted on a primary drill holder which may be slid in a horizontal plane at a fixed height to machine a workpiece which may be adjusted in its height above the surface level of the jaws to determine the suitable contact point between workpiece and drill. The height of the workpiece above the jaws is not determined by the clamping action of the jaws but rather by height adjusters which slide on vertical supports and which are fixed in an adjusted position by tightening knobs to secure the workpiece at the chosen height. The workpiece is held in line with the jaw length and the primary drill holder slides in a line perpendicular to the jaw length which requires a secondary sliding drill holder to place the apparatus in the correct position along the lengths of the jaw channels. In addition, there is no way in which the primary sliding drill holder can be employed in a vertical operational mode.

It is desirable therefore to provide an apparatus which brings together the power drill and the workpiece in a more controlled way. It is also desirable that the apparatus should be simple to set up and use, extremely versatile and of low cost.

According to the present invention there is provided a drilling support apparatus adapted to assist the machining of a workpiece using a hand held type power drill and a clamping table comprising a jaw which is displaceable towards another jaw, the apparatus comprising: a holding member adapted to support one of the drill and the workpiece; and an extension member which extends from the holding member and which is receivable in the jaws of the clamping table at a plurality of longitudinal positions along the extension member so as to allow adjusting of the vertical distance above the surface level of the jaws of a contact point between one of the drill and the workpiece and the other of the drill and the workpiece when it is supported at a jaw, the longitudinal position of the extension member being fixable by displacing the jaw towards the other jaw.

The approach of the invention is to use a classic type clamping table wherein two jaws spanning a top frame may be displaced to and away from each other, such as by tightening means located on either side of the top frame and exemplified by the Workmate™.

In one embodiment of the invention, rather than simply clamping a drill press or multi-angle drill holder to one of the jaws as mentioned above, the displacement action of the two jaws towards and away from each other is used to adjustably determine the vertical distance above the surface level of the jaws at which there can be a suitable contact point between a normally hand held type power drill mounted on the said jaws and a workpiece supported by the same jaws.

The distance of the mounted power drill above the surface level of the jaws may be adjustably determined by the displacement action of the jaws to meet a suitable contact point with the workpiece or the distance of the workpiece above the surface level of the jaws may be adjustably determined by the displacement action of the jaws to meet a suitable contact point with the mounted power drill.

In one embodiment of the invention, the primary power drill holder may position the power drill to function in both a vertical and horizontal mode of operation when mounted upon the jaws. In the terms of this invention the primary power drill holder is that element which is attached to the power drill such as around the neck adjacent to the chuck. Any further elements which would hold or guide the primary power drill holder would be considered as secondary power drill holders or guides.

One embodiment of the invention comprises a simple three piece apparatus comprising a primary drill holder and two clamping blocks. The primary drill holder is in the form of a collar with attached cylindrical length along which run narrow channels at several points around its circumference. This cylindrical primary drill holder may be inserted vertically between two confronting clamping blocks each attached to the front edge of a jaw such that when the jaws are clamped tight the clamping blocks encircle the primary drill holder fixing it firmly in chosen adjustment position. Once the neck of the drill has been fitted to the collar the drill may be held in a horizontal operational mode where it may rest on the surface of the jaws for precision work with workpieces also supported by the surface of the jaws or it may be raised to a higher level for a free handed presentation of the workpiece. The angle at which the drill faces across the surface level of the jaws may also be chosen by appropriately aligning rib projections within the clamping blocks with the channels in the cylindrical primary drill holder.

This embodiment also provides a horizontally aligned cavity in the clamping blocks into which the primary drill holder may be clamped thus holding the drill in a vertical operational mode, the cylindrical length of the primary drill holder permitting the vertical positioning of the drill to be beyond the end of the jaws if required and the rib/channel alignment of this three piece apparatus permitting the vertical operational alignment of the drill to be angled away from a perpendicular with the jaw surface to a lowered angled position.

Another embodiment of the invention also provides a three piece apparatus serving the same functions as the above described embodiment wherein the three pieces allow just sufficient displacement away from each other to permit any chosen adjustment in height or angle but remain inseparable. In this case the primary drill holder may be changed from a horizontal operational mode to a vertical operational mode by turning the whole clamping block assembly through 90° where it may equally be clamped in position by the jaws of the clamping table. In the first above mentioned embodiment the primary drill holder is repositioned on the secondary drill holder,(the clamping blocks), which is not repositioned, and in the second embodiment both primary and secondary drill holder elements are turned through 90°. In practice the linked three piece apparatus is easier to handle and to set up and the parts are less likely to become separated from each other and lost.

Another embodiment of the invention provides a four piece apparatus with the addition of a cylindrical " T " element which may be inserted vertically or horizontally into the clamping blocks in the same manner as described in the first embodiment and wherein the cylindrical primary tool holder may be inserted into a hollow section which forms the top of the " T ". This arrangement gives a slightly greater reach for drill positioning over the surface of the jaws which is particularly advantages when wanting to set up some improvised jig on the jaws for supporting and guiding a workpiece towards the drill.

In the above mentioned embodiments, the suitable contact point between workpiece and drill is achieved by adjusting the distance that the drill operates above the surface of the jaws. The invention equally provides that the suitable contact point between workpiece and drill may be determined by adjusting the distance that the workpiece lies above the level of the jaws through the displacement/clamping mechanism of the jaws.

The invention provides another embodiment for the primary tool holder which takes the form of a slidable carriage with drill collar, the carriage being guided by a channel incorporated into the surface of the jaw and running along its length. Two confronting clamping blocks, each attached to the front edge of a jaw, may hold the single vertical leg of a mini machining table at an adjustable height such that a workpiece supported on the horizontal surface of the mini machining table may be machined at a suitable contact point. An adjustable fence guide on the surface of the mini machining bench ensures that the workpiece resists any pressure the drill in its machining action. Embodiments of the invention permit two basic sorts of machining: one in which the primary drill holder is slid forward to machine a workpiece held against the fence guide on the surface of the mini machining table, and one in which the primary drill holder is locked into position in the jaw channel and a workpiece is slid between the fence guide and the drill tip. The first method is suitable for drilling holes, the second for continuous edge work when the drill is holding a router type bit, grinding stone or sander for shaping the edge of a workpiece along its length.

The apparatus of the invention can be easy to use, relatively simple and cheap to produce and extremely versatile. There may be for example provided a "V" shaped groove in the surface of the mini machining table which coincides with the line of the channel along which the drill bit arrives. It is possible to finely adjust the height of the mini machining table using the clamping action of the jaws such that a round piece of doweling no more than 10 mm in diameter may be held by one hand in the V channel while the other hand slides the drill mounted on the primary drill holder forward to pierce a hole at the centre of the doweling.

The relative simplicity of embodiments of the present invention in employing the clamping action of the jaws to adjust the height of a workpiece above the jaws, and in using the length of the jaw to directly mount a primary sliding drill holder, not only greatly reduces the number of parts and hence the costs but by reducing the number of elements to be adjusted it increases the precision of the system and the ease with which it can be set up and used.

Embodiments of the invention provide that the slidable primary drill holder may be mounted on a vertical column set in a stable base to function in a vertical operational mode in the manner of a drill press. The slidable primary drill holder may slide in a channel of similar form to that installed in the jaw surface but situated in the vertical column of the drill press. The preferred embodiment in both cases is an extruded aluminium form with the whole vertical column of the drill press being formed in such manner though the general provisions of the invention do not exclude other ways of forming channels of similar profile in both the jaw surface and the vertical column of the drill press.

Embodiments of the invention further provide that the base of the drill press should be a "Smart Drill Base" with profile means to be fitted slidably into a guide channel and specifically the guide channel form provided in the surface of the jaws and preferably also with at least three adjustably extendable feet which may form together with the protruding channel slider form an even base for sliding over an even surface or, adjusted in an irregular way, to provide a generally more or less perpendicular alignment with an irregular surface.

Embodiments of the invention further provide that the vertical disposition of the sliding primary drill holder in the vertical column of a drill press the base of which is itself mounted in slidable connection with the channel on the fixed jaw may machine a workpiece which is horizontally and adjustably presented by the clamping action of the tightening jaw, the workpiece held at a suitable level above the surface of the tightening jaw by elements preferably slidably connected to a channel on the tightening jaw such that a portion of the workpiece may eventually also rest on the upper surface of the base plate in a horizontal plane to be machined at a suitable contact point between workpiece and drill.

Embodiments of the invention will now be described, by way of example only, with reference to the following drawings in which:

Fig. 1 is a partial end view of the jaws with attached clamping blocks holding a primary drill holder in vertical alignment for horizontal operational mode for a drill, Fig.2 is a partial side view of a compact Dremel™ type drill attached to a primary drill holder, Fig.3 is a partial plan view of the ends of the jaws with attached clamping blocks holding a primary drill holder in horizontal alignment for vertical operational mode for a drill, Fig.4 is an inside view of a clamping block showing the semi circular channels in vertical and horizontal alignment, Fig.5 is a partial end view of the jaws with attached clamping blocks holding a hollow section " T

" tube in vertical alignment with inserted primary drill holder in horizontal alignment,

Fig.6 is an enlarged plan schema of two confronting clamping blocks each with a locking pin going into the other such that they remained joined, Fig.7 is a side view of a primary drill holder,

Fig.8 is a cross section schematic view of section A-A' indicated in Fig.7,

Fig.9 is a front view of a primary drill holder suitable for fitting a standard sized DIY drill,

Fig.10 is a schematic side view of the primary drill holder shown in Fig.9 with dotted lines indicating where the front and rear of the drill are fitted, Fig.11 is a partial end view of the jaws with attached clamping blocks holding a mini machining table upon which a workpiece is resting against a fence guide behind,

Fig.12 is a plan view of the mini machining table shown in Fig.11,

Fig.13 is a schematic plan view of a drill press,

Fig.14 is a side view of the base of the drill press shown in Fig.13, Fig.15 is a partial end view of the jaws, of the base of the drill press mounted in a channel of one jaw and of a fence guide mounted in a channel of the other jaw with a workpiece aligned on the base of the drill press,

Fig.16 is a side view of a base support of the drill press in channel mode,

Fig.17 is another side view of a base support of the drill press in channel mode, Fig.18 is a schematic plan view of a drill press support base,

Fig.19 is a partial schematic plan view of a drill support base, and

Fig.20 is a partial schematic side view of a drill support base.

Fig. 1 shows a drilling support apparatus for machining a workpiece held within the jaws (3) of a clamping table using a hand held type power drill (30). The apparatus includes a primary drill holder comprising a holding member or collar (1) adapted to support the drill and an extension member or cylindrical portion (Ia) which extends from the holding member and is mounted vertically within the hold of two clamping blocks (2) which attach it to the front edge of the two jaws (3). The cylindrical portion (Ia) is receivable in the jaws of the clamping table at an infinite number of longitudinal positions along the extension member so as to allow adjusting of the vertical distance above the surface level of the jaws.

On the side of the clamping blocks there are two half cylindrical channels which form the opening for a horizontal alignment of the primary drill holder and the ribs (2a) of the clamping blocks fit into channels (Ib) running the length of the cylindrical portion . In both vertical and horizontal alignment the primary drill holder may be turned to a chosen angle, the ribs and channels aligned, and then the jaws tightened. Once locked in tightened position the primary drill holder can no longer rotate within the clamping blocks because of any pressure from the workpiece.

Fig.2 shows that at the level of adjustment shown in Fig.l the primary drill holder is at its lowest adjustable point at which a hand held type power drill (30) such as a compact Dremel™ type drill may rest on and be supported by the surface of the jaw. The collar is fitted to the neck of the drill by a nut (31) which is located just before the chuck (32). The primary drill support can be adjusted upwards and held at a chosen angle and height simply by tightening the hold of the clamping blocks through the clamping action of the jaws such that the drill is held in horizontal plane above the surface of the jaws. It is this low position with the drill lying on the jaws that is one of the advantages of the invention since it is easier to support a workpiece and to guide it by the suitable positioning of clamping dogs when the drill itself is close to the support surface.

Fig.3 is a partial plan view of the end of the jaws with attached clamping blocks holding the primary drill holder in horizontal plane. Visible now are the two half cylindrical channels which form the opening for the vertical disposition of the primary drill holder. The primary drill holder can be adjusted further out or further inwards towards the jaws. It is in fact possible to turn the primary drill holder through 90° from the position shown in this figure such that the drill is in a horizontal operational position with the chuck below the surface level of the jaws. It is thus possible to position a grinding stone or sanding disk so that it may machine the end or underside of a workpiece being supported and guided by the surface of a jaw. Fig. 4 is the inside view of one of the clamping blocks showing the vertical and horizontal half cylindrical channels together with their respective engagement ribs.

Fig.5 is a side view of an apparatus similar in principle to that described above but with a hollow " T " tube extension (4) with channels (4a) along its length fitted into the clamping blocks and with the primary drill holder inserted into the hollow head section (4b) of the " T " wherein ribs prevent the primary drill holder from rotating and a tightening screw ( 4c) locks it into chosen extended position. The clamping action of the jaws still determines the height above the jaws at which the primary drill holder is held.

Fig.6 is an enlarged schematic plan view of two similar confronting clamping blocks each with a rod projection (2b) which enters a matching bore hole in the other in a mirror type engagement. The end of each rod projection is compressed at the beginning of the bore hole until reaching a wider section of the bore hole (2c) at the end of its travel at which point the compressed rod springs open with flanges now preventing its removal. The wider end section of the bore hole allows the two blocks to be pulled away from each other to the limited extent shown by arrow B which is approximately 4 mm. The inner ribs of the former embodiments have been replaced with channels (2a) which may interlock with the four wings (Ib) of the primary drill holder shown Figs. 7 and 8. The arrows marked A represent a distance equal in measure to the thickness of the jaw such that to change the position of the primary drill holder from a vertical alignment to a horizontal alignment the whole apparatus, clamping blocks and primary drill holder is turned through 90° and clamped into position. There is a wider section (Ic) shown at the base of the primary drill holder. Once the two clamping blocks are pushed together around the primary drill holder the three are inseparable, the clamping blocks can be separated up to 4 mm which allows height or rotational adjustment of the primary drill holder but the primary drill holder cannot be pulled out because of the enlarged base section (Ic). This interlocked apparatus is much easier to handle for the user. Fig.9 is a front view of a primary drill holder (5) suitable for a conventionally sized DIY type drill with a tightening thread and button (5a) and runner projection (7) underneath its base.

Fig.10 is a side schematic view of the same primary drill holder showing a long base (6) and the runner projection for fitting in a channel. Towards the rear, an adjuster screw (8) may be raised or lowered to suit the rear profile (40a) of any particular drill thus giving it support at both its neck end (40) with the collar and its rear end. Further adjuster screws may be added on each side at the rear end to prevent any lateral movement. This gives the drill a more precise machining line or indeed the primary drill holder may be formed to suite a particular make or model of drill thus giving it lateral support at the rear. A tightening knob (9) at the very rear of the primary drill holder may tighten a brake element (9a) in a guidance channel.

The primary drill holder may thus operate in two modes: to slide in a channel to approach a workpiece or to be locked in a channel to be approached by a workpiece.

Figs. 11 and 12 are a side view and plan view respectively of a table support or mini machining table with a vertical portion (11) clamped between two clamping blocks (10). The clamping blocks each have a lip portion (10a) at either end which enters a vertical slot in the vertical portion of the table to keep a table portion (12) parallel with the length of the jaws when the mini machining table is adjusted in height relative to the surface of the jaws.

There is shown on the table a workpiece (W) which rests against an adjustable fence guide (13), the fence guide having two pins (13b) which can be inserted into a series of receiving holes (13a) set in the worktop. Point X marks the point at which a drill bit held in a drill mounted on a PDH of the type shown in Figs.9 & 10 will arrive when the PDH is slid along channel 3a. In this embodiment of the invention the height drill above the surface of the jaw cannot be adjusted but the suitable contact point between workpiece and drill can be determined by the clamping action of the jaws in holding the mini machining table at the suitable height above the jaw. In this example the hole at point X is at a midpoint at the side of the workpiece but it could equally be more towards the top edge of the workpiece if the table were adjusted downwards or more towards the bottom edge if the height of the table were adjusted upwards.

When the fence guide is removed a "V" channel (14) may hold a workpiece (Wa) in a line with the trajectory of the drill bit for the "end drilling" of a workpiece such as a round section dowelling. A stop may be locked into the channel at a suitable point to stop the travel of the primary drill holder and thus determine the depth of the hole drilled.

Figs. 13 and 14 are a plan view and partial side view respectively of a drill press wherein a vertical column (15) in extruded aluminium with a channel profile (15a) matching the channel profile 3a provided in the surface of the jaw is mounted on a base support (18). Within the hollow section of the vertical column there is inserted a compression return spring (17) which pushes on a plate (16) having a projection (16a) which protrudes into the guidance channel (15a) forcing the return of a sliding primary drill holder back up the vertical column when hand pressure on the drill and sliding primary drill holder is taken away. A "V" shaped channel (18a) in the upper surface of the base support provides a holding alignment for a workpiece (Wa) with the descent of the drill X and a "V" shaped channel (Wb) on the underside of the base support provides a holding alignment with the trajectory of the drill descent for a workpiece (Wb) over which the base support is placed.

Also found on the underside of the base support is a runner projection (19) similar in profile to the runner (7) found on the underside of sliding primary drill holder. Also found on the underside of the base support are at least three adjustably extendable feet (20) which enable the base support to operate in three modes. The first is a flat surface mode in which the at least three feet are extended by the same amount as the runner projection 19 so that the base support is horizontally stable when moved over a flat surface. The second is an uneven surface mode as shown in Fig.14 wherein the feet are adjusted to take account of an uneven surface and still produce a descent of the drill generally perpendicular to the general horizontality of the surface. In the case of Fig.14 the irregularity occurs because the support base is placed over a workpiece in order to drill. The third mode is a channel mode where the feet are completely withdrawn to allow the runner 19 to be inserted into a channel as shown in Fig.15

Fig.15 shows the drill press slidable mounted in a channel on the jaw with a profile bit X locked in a height position above the jaws by means of the channel lock 9 at the rear of the primary drill holder carriage. The mini machining table is height adjusted by the clamping action of the jaws such that the workpiece aligned by fence guide 13 and clamped to the worktop 12 is in a suitable contact position with the profile bit X to have its end shaped by the sliding displacement of the drill press.

In Fig.16 the base support of the drill press is put into channel mode, the feet 20 being completely withdrawn to allow the runner (19) to be attached to a channel (3a) on one jaw (3). On the other jaw (33) a fence guide (21) is fixed in a channel (33a), the support height of the fence guide above the surface of the jaws equalling that of the height of the support base. A workpiece (W) may be presented in a horizontal plane parallel to the surface of the jaws and resting on the upper surface of the drill press base support to be drilled at a selected point in part determined by the extent to which the clamping action of the jaws pushes the fence guide and hence workpiece forward. The arrangement here shown provides excellent possibilities for repetitive drilling at points along the length of the workpiece. There are two potential modes of operation for this when a fence guide supports a workpiece on one jaw and presents it to a drill press mounted in a channel on the second jaw. In the first mode the drill press may remain in fixed position in the channel and the workpiece slid along the fence guide to be drilled at repetitive points along a straight line. In the second mode the workpiece may be set at fixed position on the fence guide and the drill press slid in the channel to drill the workpiece at repetitive points along a straight line.

Fig.17 presents an alternative machining set up to that shown in Fig.16 wherein, in place of the raised fence guide (21) the compact machining table (11 & 12) is mounted in channel (33a) of jaw (33) by means of a projecting runner form (12a) which has been pivoted downwards around axis point (12b) the worktop (12) having the same height as the base support (18) of the drill press which in turn has been mounted in channel (3a) of jaw (3) by a similar projecting runner form (19) pivoting downwards from axis point (19a). A fence guide (13) may be adjustably positioned on worktop 12 in a line perpendicular to that originally shown in Fig.12 when a second series of fixing holes (13a) are provided in two lines perpendicular to the first series. There is also provided on the drill support base an adjustable fence guide (22) mounted on a thread activated by a knob (23) which may be retracted along the line indicated by the arrow A to nest within the drill press column (15). Fence guide (13) may be tightened towards fence guide (22) through tightening action on jaw (33) such that the two fence guides act in the manner of a clamp holding the workpiece (W) tightly in position for a machining trajectory (X).

Fig.18 shows a schematic plan view of a drill press support base (18) provided with an adjustable fence guide together with four adjustable height feet (20) in the form of bolts which may be adjusted in receivable threads within the drill support base.

Figs.19 and 20 are a partial schematic views of a drill support base provided with an alternative "U" shape adjustable fence guide which allows the line of the workpiece (W) to touch the edge of a revolving tool such as a sander or grinder situated at machining point X in a controlled way without approaching the revolving tool beyond the line determined by the fence guide.

Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention.