GB2497110A - Adjustable Doweling Jig For Preparing Aligned Bores - Google Patents

Abstract

An adjustable doweling jig for preparing aligned bores comprises a bottom plate 10 with up stands 12 and guides 11 sliding in bores (22, Figure 7), angular pieces 15 on either side of the stands 12 are attached to a spacer 16 sliding on the guides 11, locking screws 9 passing through the spacer or bottom plate and engaging the guides to lock them in place. An end stop 13 may slide on a guide 14 having corresponding locking screw 20. An arrangement of different diameter bores are formed in the bottom plate (17-19, Figure 1) and reducing sleeves (21, Figure 2) may be provided for further diameters. The spacer and angled members slide together and can be adjusted and locked in place and the end stop adjusted and locked in place to give the required distance of the bores to be drilled from the edges of the workpiece. The angular pieces may have markings on them to aid in aligning a mark on a workpiece with the bores. The jig may be hand held.

Description

Description

The present invention relates to an easily adjustable dowelling jig which is used to guide a drill to form bores in respective work pieces in accurately corresponding positions so that a dowel or bolts can be inserted in the corresponding bores, and the joint surfaces of the work pieces can be brought together to form an accurate joint.

Complex and ex-pensive tooling is available to aid in the drilling bores for receiving dowels in joints which are extensively used in wood working. One system has been devised to use biscuit-shaped connection elements instead of cylindrical dowels but in each case, complex and expensive machinery is used and intended for work shop use. Further more simple marking guides have been available to assist in the drilling of bores for dowels but because considerable accuracy is required for the formation of a successful joint it is important that significant, skill, care and attention is used if successful and neat joint are to be formed.

Examples of commonly required dowelling joints are right angled joints between posts and rails in flurniture, mitre joints in picture frames and joints between edges of boards which are formed together, for example to provide a table top. This latter application can be considered particularly demanding because a series of spaced dowels are required and any misalignment of a single bore will create problems. It is highly desirable that the joint when formed is neat and essentially no further working upon the surfaces of the joint is required. For example with inoulded products such as picture frames and the like, it is most important that the joint faces meet precisely and neatly.

Although the invention is not confined to embodiments when the dowelling jig is hand held, an embodiment that facilitates the hand holding of the jig is highly desirable. This permits a high degree of portability and use in a simple workshop or on site where construction is taking place. There is a need for a device that can be used without a high level of skill or particular attention and yet the drilling process can be affected very speedily. Thus at least preferred embodiments of the invention lend themselves to a significant practical advantage both to professionals who can easily and speedily with a simple hand held electric drill or even the unskilled handyman. Description This present invention relates to an easily adjustable dowelling jig which is used to guide a drill to form bores in respective work pieces in accurately corresponding positions so that a dowel or bolts can be inserted into the corresponding bores, and joint surfaces of the work pieces brought together to form an accurate joint.

Complex and expensive tooling is available to aid the drilling of bores for receiving dowels in joints which are extensively used in woodworking. One system has been devised to use biscuit-shaped connection elements instead of cylindrical dowels but in each case complex and expensive machinery is used and intended for workshop use. Further more simple marking guides have been available to assist the drilling of bores for dowels but because considerable accuracy for the formation of a successful joint it is important that significant, skill care and attention is used if neat joints are to be formed, Examples of commonly required dowelling joints are right angled joints between post and rails in furniture, mitre joints in picture frames and joints between the edges of boards which are formed together, for example a table top or the joining of work tops This latter application can be considered particularly demanding because a series of spaced dowels are required and any misalignment of a single bore will create problems. It is highly desirable that the joint when formed is neat and essentially no further no further working upon the surfaces of the joint is required. For example when joining two work top work pieces together it is most important that joint faces meet precisely and neatly and no further work is necessary.

Although this jig can be used by professionals, it, can also be used just as easy used by the amateur allowing him to make the necessary depth and length adjustments in seconds, without adding or subtracting parts to the jig.

And without the complication of setting out which is normal in forming a joint The sliding top section of the jig allows easy depth setting whilst the end stop allows adjustments in length whether joint or mitre.. With locking screws to hold the jig in the required settings.

The top section slides in opposing directions on the guides which are fixed to the bottom plate with further lateral stability of the top section being given by the up stands on the bottom plate which intersect with the top sliding section.

Or alternatively having the guides fixed in the spacer and sliding in bores in the bottom plate.

The work pieces can have differing thicknesses requiring different depth settings on the dowelingjig. These new settings can easily be obtained by resetting the sliding top section to the bring the bore holes to the required depth and simply tightening the locking screws without the use of washers or packing pieces.

Their are occasions when dowels are used in an intermediate position such as shelving. The top section and the end stop are detachable if the jig is required to work in these positions As with the fitting of a kitchen worktop joint, biscuits can be used but this requires a machine to cut the holes for the biscuit which although it has an accurate depth setting has no accurate means of setting the lengths which this dowelling jig does.

The jig can be held in position with the hand or clamped in position before the bores are made.

Differing work pieces require differing diameter dowels, this can be accommodated for in the jig, by having differing lines of different diameter bore holes. Or lines of bore holes having the same diameter into which reducing sleeves with the same external diameter but differing internal diameters bores fit. The top of the angular pieces on the dowel jig can also be marked with lines which could then be used to coordinate the jigs position in relationship to any line drawn on the work pieces.

For illustrative purposes only, embodiments of the invention will now be described with reference to the accompanying drawings of which: Fig 1 is a perspective view of a first embodiment of the invention when assembled; Fig 2 is a perspective view of a first embodiment of the invention when assembled using reducing diameter sleeves.

Fig 3 is an end elevation of a first embodiment the invention, showing the reducing sleeves in their bores.

Fig 4 Gives an exploded view of the invention.

Fig 5 Gives an end view of a first embodiment of the invention with the work pieces in place for boring Fig 6 is a further drawing showing the end elevations of the invention.

Fig 7and 8 give a view of the invention having guides fixed in the spacer and sliding up or down in bores in the bottom plate.

The illustrated embodiment is a device adapted to be held by hand and used for a wide range of dowelling joints to be formed in pre-cut and finished components.

Turning initially to Fig 1 the jig comprises a bottom plate 10, up stands on the bottom plate 12, which pass between the angular pieces 15 and guides 11 which pass through the spacerló onto which the angular pieces 15 are attached.

The spacer 16 slides on the guides 11 which have locking screws 9 which are thread and enter threaded bores in the spacer 16 engage which engage with guides 11.

This embodiment also includes an end stop 13 which slides on guide 14 having a locking screw 20 which is threaded and enters a threaded bore which engages with guide 14.

The drawings illustrate one possible array of through bores formed in the bottom plate,(see Fig 1) The bores comprise in this example of through bores 17, 18, and 19, having different diameter bores.

This embodiment also incorporates additional sets of through bores,(see Fig 2) having reducing sleeves 21 which can having differing internal bores.

The embodiment can have can have guides 11 fixed in the spacer 16 which slide in the bores 22 (see Figs 7 and 8).

The reducing sleeves could be made of a suitable hardened material and be replaced if wear occurs.

To provide adjustability reducing sleeves with an internal diameter bore, that corresponds with the dowel diameter that is to be used could be inserted in the through bore holes-The top section then slides up or down to give the required depth, being held in place by the locking screws. The end stop is set and locked in place giving the required distance of the bores from the end of the It has been found that the preferred embodiment of this invention is easy and accurate to use without special skills or even good eyesight even with demanding applications. Test have been conducted on differing thicknesses and widths of materials and accurate joints have been formed. Fig 5 gives an illustration of such a joint being formed.

The embodiments shown in the drawings are very easily adjustable, and requiring no additional parts, packing or pieces. And can be used very easily by even the unskilled.