WO1988010177A1

WO1988010177A1 - Improved cutting guide

Info

Publication number: WO1988010177A1
Application number: PCT/AU1988/000223
Authority: WO
Inventors: Brian Richard Petherick
Original assignee: Petherick Bros. Pty. Ltd.
Priority date: 1987-06-26
Filing date: 1988-06-27
Publication date: 1988-12-29

Abstract

A guide for cutting a mortise comprising a drill guide part (2) having a drill guide aperture (21) passing therethrough, the aperture (21) is composed of a plurality of overlapping cylindrical shapes (20) each of the same diameter and parallel cylindrical axis which define a common plane, the drill guide (2) is held in a clamp means (3) which has two clamp arms (4, 5) and (6, 7) one at each end, these are clamped to the work to be drilled and held in place thereon by means of plates (12, 13) and (14, 15) and screw threads (8 and 9), the clamp also includes two ridge parts (16 and 17) with guides (18) and (19) that have centering positions (27) included therein, the drill guide part (2) is contained between bridge parts (16 and 17) and can slide along the bridge parts (16 and 17) by one half a diameter of each shape (20), thus overlapping apertures can be drilled that will only leave an aperture with slight arcuately pointed parts which can then be easily removed.

Description

IMPROVED CUTTING GUIDE

This invention relates to a cutting guide especially intended for cutting of a mortise to assist in fitting of a lock within a door.

It is well known to use a drill bit to cut in successive operations, adjacent at the apertures along the edge of a door as a first step in cutting such a mortise.

Two problems exist with the present manual arrangement.

The first is that a drill bit and especially one intended for use with wood will require a start within existing material, and sufficient width of material so that the bit will not veer from the intended cutting direction.

For this reason, in cutting a mortise for a typical mortise lock, apertures are cut with a reasonable distance apart and usually, to such an extent, that there is either negligible overlapping or no overlapping between adjacent apertures.

Subsequently,, the mortise aperture which is required to have broadly planar sides will then be worked on manually but a use of a chisel cutting out the substantially triangular parts left between adjacent apertures cut in this manner.

It is, perhaps, unnecessary to point out that this technique which is the conventional technique presently used, is both time consuming and has some capacity for error insofar that subsequent cleaning of the material uses hand operated chisels.

It is an object of this invention to propose apparatus whereby a mortise aperture of this type can be effected somewhat more quickly than has hitherto been the case.

The invention then can be said to reside in a guide for cutting a mortise wherein a guide part comprises an aperture by which a drill bit, when located therein, will be restrained from movement only in any lateral direction with respect to the guide part with respect to the cylindrical axis of the drill bit, clamp means adapted to hold the guide part relative to a work piece, and means to allow for relocation of the drill bit to an adjacent position of the said first said first position of the drill bit wherein the guide part will further provide means to constrain the drill bit so that the drill bit is restricted from movement only in lateral direction with respect to the guide and with respect to the cylindrical axis of the drill bit.

In a further form of this invention, this can be said to reside in a guide for cutting a mortise comprising clamp means and a drill guide part held therewith having a drill guide aperture passing therethrough, the shape of the aperture being that defined by a plurality of overlapping cylindrical shapes, each of the shapes being of the same diameter, each cylindrical shape having its cylindrical axis parallel with the other cylindrical axis, the axis of each cylindrical shape aligned with the other cylindrical axis to define a common plane, and the position of each cylindrical shape being in an overlapping location with adjacent cylindrical shapes each having the same extent of overlap with the adjacent shapes.

By providing such a guide, the position of the drill bit can be variously located and held adequately so that drilling can occur even though it is substantially overlapping an already existing hole and can be kept substantially aligned.

The result of this is that holes can be drilled in much closer relative location one to the other leaving, at the very least, only very small parts on the sides of the then cut slot shapes to be cleaned up manually.

It is, of course, implicit that there are clamp means to hold the drill guide part relative to the work piece.

In preference, the clamps means are such that the drill guide part can either be moved relative to the clamp means or, in an alternative situation, the clamp means can be variously positioned so that the drill, when used in conjunction with the drill guide part, can be held in various positions to effect the effective thorough drilling of the mortise.

In preference, the cylindrical shapes of the drill guide part each overlap to the extent of half the diameter of the cylindrical shape.

In preference, the drill guide part is affixed with respect to the clamp means, so that this can be moved to assume two positions, these comprising a first position, and a second position which is off-set from the first position in a lateral direction and in the elongate direction of the plane defined by the axes of the cylindrical shapes, to the extent of half the distance between adjacent cylindrical axes.

In preference, there are retaining means whereby to hold the drill guide part relative to the clamp means.

In preference, such retaining means are comprised of two pins, one located at each of the respective ends of the drill guide part and located within the body of the clamp means and adapted to be positionable in at least two positions, one of which protrudes into a slot within which the drill guide part is located and adapted to interlock with an appropriately located aperture within the drill guide part, and in the other position, is retracted to allow for freedom of movement of the drill guide part relative to the clamp.

In preference, the clamp means are comprised of two clamps, each including two clamp arms each of which is supported by a screw threaded rod having an opposite hand thread at one end as compared to the other, and such that by rotation of a tightening handle, the respective clamp arms are bought together or shifted apart while maintaining a relative position of the drill guide part with respect to a central position between the respective pairs of clamp arms.

For a better understanding of this invention, it will now be described with the assistance of drawings which:

FIG. 1 is a perspective view of the guide according to the preferred embodiment being located on the edge of the door;

FIG. 2 is an underneath view of the guide as in FIG. 1 ;

FIG. 3 is a perspective view as in FIG. 1 separate from the door;

FIG. 4 is a top view of the guide;

FIG. 5 is a side elevation of the guide;

FIG. 6 is an end view of the guide; and FIG. 7 is an alternate side elevation of the guide from FIG. 5.

Referring in detail to the drawings, the guide 1 is comprised of two main parts, a first being a drill guide part 2 and a clamp part 3.

The clamp part 3 includes, at each end, two clamp arms 4 and 5 at the one end and 6 and 7 at the other, each of the clamp arms being held in position by screw threaded rod 8 in the one case and 9 in the other.

The screw threaded rods 8 and 9 are each an opposite hand thread at a respective end so that a rotation of the respective handle 10 or 11 will have the result in a first case of bringing both of the clamp arms 4 and 5 and 6 and 7 in together so as to keep the clamp part 3 central, or in the alternative case, by rotation in the alternate direction, cause them to separate.

Plates 12 and 13 on the one hand and 14 and 15 on the other, engage with the screw threaded rod and provide the thread coupling between the respective rods 8 and 9 and the arms 4, 5, 6 and 7.

By using separate plates which are separately attachable to the arms, this does mean that the assembly of the arrangement can be easily effected insofar that the screw threaded rods 8 and 9 can be located in position with a central most rotatable connection which is not, indeed, shown but exists to hold each of the screw threaded rods 8 and 9 longitudinally fixed relative to the clamp part 3.

The clamp part 3 includes two bridge parts 16 and 17 and extending below such bridge parts are guide 18 and 19.

The drill guide part 2 iε adapted to be slidable along the respective bridge parts 16 and 17, the extent of this movement being equal to one-half the diameter of each of the aperture shapes shown in slot 20.

Slot 20 ϊs constituted by being comprised of seven overlapping apertures so that each side wall is defined by a plurality of shapes which are, indeed, the approximate equivalent of a quarter segment of the circular periphery, the aperture being made by a plurality of aperture shapes each of which is of the same diameter and each of which has the aperture shape parallel with respect to the other shapes and each of which has the axis of the circular shape co- planar with the other axes of the other apertures.

The material from which the drill guide part 2 is made is such as to provide sufficient wearing resistance so that a drill bit which has its outer peripheral shape closely matching that of the aperture shape defined by the various apertures in the drill guide part 2, will, indeed, be adequately held in such an alignment as it is used to drill an aperture below the part 2.

It is, of course, conventional to drill directly into a piece of metal or a piece of wood by drilling an adjacent number of apertures.

The conventional problem, however, is that there is no centre available for a drill to bite into the material to start the drilling action if the apertures are, indeed, too close together and it is, therefore, generally impossible to achieve close adjacent drilling.

This, of course, has been overcome by providing a relatively deep bearing guide where each of the shapes are in such an overlapping relationship that the projected portion such as at 21 , is relatively small.

More important, however, is that by arranging that the guide part 2 can be shifted by exactly half the diameter, this then means that by entering through the slot with a drill bit which closely matches the diameter shape of the respective apertures, then this will adequately hold the bit to clean out the remaining projecting parts 21.

The guide part 2, aε was stated previously, is adjustably movable by reason of wings 23 and 24 being held by bolts such as at 25 and 26 through a slot within the reεpective bridges 16 and 17, the length and shape of the slot in each case being such as to allow for this relative sliding movement.

Guides 18 and 19 can each be used first of all to locate a centre position, for instance, by using pointer 27 and 28, and the shape of the guides 18 and 19 are otherwise such including a central aperture at 29, so that additional apertures and cut-out parts can be marked and effected by using such a guide. In addition, there are retaining means 30 which control the position of pins not shown so that in one position the pins are allowed to interlock with the drill guide part and in another position, achieved by rotation of toggle 31 the pin in each case is retracted allowing for repositioning of the drill guide part.

While this then describes the preferred embodiment at this time, it will be appreciated that a number of additional features can now be added, including adding to the guide part further apertures and, indeed, markings, whereby additional cuts and markings on the door edge can be achieved.

In use, any one or more of the part of these aperture defining a cylindrical shape, can be used and can be variously positioned although according to a conventional method of use, a drill bit is driven through the respective parts of the drill guide part to a set depth, the drill guide part is then shifted through one half diameter of the cylindrical shape and all of the apertures are then further drilled which leaves very slight arcuately pointed parts which can then be very easily and extremely quickly removed.

It has been found that using the technique described, can very significantly reduce the time that has been necessary to cut a mortise for a lock in the end of a door, the time reduction being from a previous approximately 30 minutes to now approximately 5 minuteε.

Claims

CLAIMS:

1. A guide for cutting a mortise wherein a guide part comprises an aperture by which a drill bit, when located therein, will be restrained from movement only in any lateral direction with respect to the guide part with respect to the cylindrical axis of the drill bit, clamp means adapted to hold the guide part relative to a work piece, and means to allow for relocation of the drill bit to an adjacent position of the said first said firεt poεition of the drill bit wherein the guide part will further provide means to constrain the drill bit so that the drill bit is restricted from movement only in lateral direction with respect to the guide and with respect to the cylindrical axis of the drill bit.

2. A guide for cutting a mortise comprising clamp means and a drill guide part held therewith having a drill guide aperture passing therethrough, the shape of the aperture being that defined by a plurality of overlapping cylindrical shapes, each of the shapes being of the same diameter, each cylindrical shape having its cylindrical axis parallel with the other cylindrical axis, the axis of each cylindrical shape aligned with the other cylindrical axis to define a common plane, and the position of each cylindrical shape being in an overlapping location with adjacent cylindrical εhapes each having the same extent of overlap with the adjacent shapes.

3. A guide for cutting a mortise as in either of the preceding claims wherein the clamp means are such that the drill guide part can be moved relative to the clamp means.

4. A guide for cutting a mortice as in preceding claim 2 or 3 when read through 2 further characterised in that the cylindrical shapes of the drill guide part each overlap to the extent of half the diameter of the cylindrical shape.

5. A guide for cutting a mortice as in any one of the preceding claims wherein the guide part is affixed with respect to the clamp means so that this can be moved to assume two positions, these comprising a first position, and a second position which is off-set from the first position in a lateral direction and in an elongate direction of the plane defined by the axes of the cylindrical shape, to the extent of half the distance between adjacent cylindrical axes.

6. A guide for cutting a mortice as in either of preceding claims 3 or 5, further characterised in that there are retaining means whereby to hold the drill guide part relative to the clamp means, such retaining means comprising two pins, one located at each of the respective ends of the drill guide partε and located within the body of the clamp meanε, and adapted to be poεitϊonable in at least two positions, one of which protrudes into a slot within which the drill guide part is located and adapted to interlock with an appropriately located aperture within the drill guide part, and in the other position, is retracted to allow for freedom of movement of the drill guide part relative to the clamp.

7. A guide for cutting a mortice as in any one of the preceding claims wherein the clamp means are comprised of two clampε, each including two clamp arms each of which is supported by a screw threaded rod having an opposite hand thread at one end, as compared to the other, and εuch that by rotation of a tightening handle, the respective clamp armε are bought together or shifted apart while maintaining a relative position of the drill guide part with respect to a central position between the respective pairs of clamp arms.

8. A guide for cutting a mortice substantially as described in the specification with reference to and as illustrated by the accompanying drawings.