WO1998001252A1

WO1998001252A1 - Combined cross-head screwdriver and countersinking tool

Info

Publication number: WO1998001252A1
Application number: PCT/GB1997/001838
Authority: WO
Inventors: Keith Martyn Jones
Original assignee: Keith Martyn Jones
Priority date: 1996-07-09
Filing date: 1997-07-08
Publication date: 1998-01-15
Also published as: GB9614350D0; GB9804643D0; GB2318997A

Abstract

A combined cross-head screwdriver and countersinking tool comprises a screwdriver tool (10) which is secured permanently to a milling-type countersinking tool (12). The two tool portions are co-axially aligned. The combined tool is suitable for insertion into a chuck of an electric or hand-operated drill. For safety, the countersinking tool (12) comprises cutting blades (16) which are orientated to cut in anti-clockwise rotation of the tool. In use of the tool, the tool is rotated anti-clockwise in order initially to drill a hole in softwood by means of the screwdriver tool (10), and subsequently to countersink the entry to the hole. The tool is then removed from the hole formed, a screw inserted into the hole, and the tool rotated clockwise to drive a screw into the workpiece. The reverse orientation of the countersinking cutters ensures that an operator's fingers will not be cut should the screw be held upon initial insertion.

Description

COMBINED CROSS-HEAD SCREWDRIVER AND COUNTERSINKING TOOL

In woodworking, it is common practice to countersink a workpiece which is to be secured by screws, in order that the screw heads can become received beneath the surface of the workpiece when inserted; a top surface of the screw head may be left at, or slightly below, the workpiece surface after insertion.

A countersinking tool is commonly in the form of a conical milling tool which is applied by means of a drill to a preformed hole (of lesser diameter) in order to create a bevelled entry to the hole.

Conventional operation requires three tools: a twist drill to form the hole, a countersinking tool, and a screwdriver for insertion of the screw. Whilst in many operations holes can be drilled and countersunk in batches, the tool changing necessary remains laborious and time- consuming.

It is an object of the present invention to provide a drill tool which can be useful in many circumstances, at least when working with softwoods, and which can reduce or eliminate tool changes ordinarily required.

The invention provides, in one of its aspects, a drill tool comprising in combination a cross-head screwdriver tool and a countersinking tool.

It has been found that for many applications in working softwoods the cross-head screwdriver tool in such a combination can operate satisfactorily as a drill to form at least a pilot hole, for the screw to be inserted, prior to countersinking the hole so formed. The same tool can then be used for insertion of a screw.

The most well-known forms of cross-head screwdriver tools are Phillips and Posidrive, and either form can be employed in accordance with the invention.

The screwdriver tool and the countersinking tool, in combination, may be permanently assembled together or may be separable.

For safety reasons, cutters of the countersinking tool may be orientated for cutting in the opposite direction (ordinarily anti-clockwise) to the direction of rotation required for screw insertion.

The accompanying drawing illustrates a tool which illustrates the invention by way of example.

A combined cross-head screwdriver and countersinking tool comprises a screwdriver tool 10 which is secured permanently to a milling-type countersinking tool 12 in a unitary tool body. The two tool portions are co-axially aligned. The combined tool is suitable for insertion into a chuck of an electric or hand-operated drill.

The screwdriver tool 10 has a tip 14 of Posidrive form (size No. 2) , projecting from the apex of the conical countersinking tool 12.

The countersinking tool 12 comprises cutting blades 16 which are orientated to cut in anti-clockwise rotation of the tool, as viewed looking towards the tip of the tool from a shaft 18 of the tool which is suitable for insertion into the drill chuck. In use of the tool, the tool is inserted into the drill chuck and then rotated anti-clockwise by operation of the drill. In a single drilling operation, the tool is used initially to drill a pilot hole by means of the screwdriver tool 10, and subsequently to countersink the entry to the hole by means of the countersinking tool 12. The tool is then removed from the hole formed and a screw inserted into the hole. The tool is next engaged with the screw and rotated clockwise by the drill to drive the screw into the workpiece. The reverse orientation of the countersinking cutters ensures that an operator's fingers will not be cut should the screw be held upon initial insertion and the cutters touch the fingers.

The length of projection of the screwdriver tool 10 from the countersinking tool 12 may be selected according to the depth of starter hole to be formed. The combination tool may be formed with a crosshead driver which in the axial direction merges smoothly with a four-bladed countersink cutter; this may provide the advantage of throwing the wood arisings more efficiently. Furthermore, the four crosshead driver blades might be modified from a conventional construction in order to improve initial cutting efficiency (when being used as a drill) . This might be done by hollow grinding the blade edges.

In a generally known manner, a fixed or adjustable collar may be provided on the tool to limit the extent of countersinking (or countersinking and counterboring) effected.

Claims

1. A drill tool comprising in combination a cross-head screwdriver tool and a countersinking tool.

2. A tool according to claim 1 in which the screwdriver tool and the countersinking tool are formed by a unitary tool body.

3. A tool according to either of claims 1 and 2 in which cutters of the countersinking tool are orientated to cut in an anti-clockwise direction of rotation as viewed looking towards a workpiece in use.

4. A tool according to any one of claims 1 , 2 and 3 comprising a shaft suitable for insertion into a chuck of an electric or hand-operated drill.

5. A combination screwdriver and countersinking tool substantially as hereinbefore described with reference to the accompanying drawing.

6. A method of inserting a screw into a workpiece of softwood or similarly soft material comprising the steps of inserting a combination screwdriver and countersinking tool into a drill chuck, operating the drill so as to form by means of the tool in a single drilling operation a countersunk pilot hole in the workpiece, withdrawing the tool from the hole and inserting a screw into the hole, and engaging the screw with the tool and driving the screw into the workpiece by means of the tool in operation of the drill.

7. A method of inserting a screw substantially as hereinbefore described with reference to the accompanying drawing.