AU2018101473B4

AU2018101473B4 - Improvements relating to cutting devices to make internal keyways, splines and other shapes in blind bores and through bores

Info

Publication number: AU2018101473B4
Application number: AU2018101473A
Authority: AU
Inventors: Martin Forrer
Original assignee: Elmass (australia) Pty Ltd; Elmass Australia Pty Ltd
Current assignee: Elmass (australia) Pty Ltd
Priority date: 2017-11-22
Filing date: 2018-10-02
Publication date: 2019-05-30
Anticipated expiration: 2026-10-02
Also published as: AU2018101473A4; DE202018106045U1

Abstract

1 3 The documented invention improves the functionality of the mentioned apparatus 4 in Patent 233260 to cut internal keyways in through bores and enables it to cut 5 internal keyways, internal splines internal hexagons and other internal polygons 6 without alignment errors in through bores and blind bores by substituting the 7 guide tube and close ended foot piece of the above mentioned apparatus with a 8 guide tube (7) that has a wider receiving body (1) with integrated positioning 9 devices (3) and (13), onto which, using several fastening devices (11) that are 10 not positioned in the centre of the guide tube (7) or its receiving body (1), an 11 open ended, detachable foot piece (5), having the mating positioning devices 12 (10) and (14), is mounted in a defined position in such a way, that the resulting 13 cutting forces are distributed equally onto the designated area (2) of the receiving 14 body (1) and area (16) of the open ended detachable foot piece (5) and allows 15 the internal polygon to be machined by at least the length of screw, that secures 16 the close ended foot piece through the blind bore of the close ended foot piece to 17 the centre of the lower end of the mating guide tube, closer to the end of the blind 18 bore in the work piece.

Description

IMPROVEMENTS RELATING TO CUTTING DEVICES TO MAKE INTERNAL KEYWAYS, SPLINES AND OTHER SHAPES IN BLIND BORES AND THROUGH BORES

Applicant: Actual Inventor:

Elmass (Australia) P/L, Martin Forrer

ABN:20 084 286 484

The invention is described in the following statement:

The following statement is a description of improvements to the Australian Patent 233260 including the best method performing it known to us.

The apparatus in Patent 233260 is designed to cut internal keyways in through bores. The apparatus can be mounted on any slotting machine or any machine which is provided with a longitudinally displaceable working spindle, the a guide tube, that supports a shiftable cutter is attached. An eccentric, close ended foot piece is mounted onto the guide tube apparatus comprising of a head piece with an integrated advance mechanism onto which and is secured with a screw that goes through the centre of blind bore of the close ended foot piece to the centre of the lower end of the guide tube.

This keyway cutting apparatus is characterized in that there is a guided hole provided near the free end of this guide tube and directed transversely of this axis on the latter, a tool provided externally with a cutting edge and internally with a beveled or wedge-shaped portion, with which there co-operates the correspondingly beveled lower end of a feed rod slidable in the guide tube, this rod being displaceable by manual advancing means arranged on the head, in such a way that it shifts the tool outwards against a spring force.

By these means the tool can be gradually be shifted, so that at every working stroke of the machine a shaving is removed from the work piece until the keyway has reached the desired depth.

It can be used to cut splines and other shapes (keyways, splines and other shapes hereinafter called internal polygons), but the close ended detachable foot piece has to be lined up very precisely to the cutting edge of the cutter to avoid alignment errors, because there is no provision to force the position of the detachable foot piece to be in line with the cutter. The undefined position of the close ended detachable foot piece can also create misalignment problems for internal polygons mainly in larger bore sizes or for repetitive production work that requires the replacement of cutters during mass production. Whist it is possible to cut internal polygons in blind bores with this apparatus, its use to do so is restricted because the length of screw that secures the close ended foot piece onto the lower end of the guide tube goes through the centre of blind bore of the close ended foot piece to the centre of the lower end of the guide tube and as a consequence results in large distance between the bottom of the detachable foot piece and the cutting edge of the cutter. To cut internal polygons in blind bores with very limited space below the keyway, special guide tubes, that look similar to the assembled tool, but do not have a detachable foot piece, have to made for each bore size. This is very expensive and requires a lot of space to store these individual guide tubes for blind bores.

The present invention relates to the above mentioned apparatus and improves its overall functionality to cut internal polygons with minimal alignment errors in cylindrical openings of any shape that have either a closed end (hereinafter

2018101473 10 May 2019 called blind bore) or an open end (hereinafter called through bore) if mounted on a manual, NC or CNC machine or on any suitable machine tool with a longitudinally displaceable working spindle by substituting the existing guide tube and close ended foot piece of the above mentioned apparatus with a guide tube with integrated positioning devices and an open ended foot piece with matching positioning devices.

The invention also reduces the required storage space and costs of the existing guide tubes for blind bores and minimises the distance between the lower end of the detachable foot piece to the cutting edge of the cutter that is sliding in the dedicated square tool holding section of the guide tube by at least the length of the screw that is required to mount the close ended foot piece of the above mentioned apparatus onto its mating guide tube, the improvement comprising a guide tube and an open ended detachable foot piece that is accurately positioned on it in such a way that it prevents alignment errors of any internal polygon to be cut and secured with fastening devices that are not mounted to the centre of the guide tube or its receiving body.

According to the invention, the subsequently documented device substitutes the guide tube and detachable foot piece of the apparatus described above with a guide tube having an integrated positioning device on to which an open ended detachable foot piece that interconnects with the above mentioned locating device is mounted to cut internal polygons in through bores and blind bores, which have only a minimal recess, or a small side bore to allow the swarf to fall off, as well as to produce these internal polygons without alignment errors, as far as the device is used in the sense of the apparatus described above.

2018101473 10 May 2019

The invention is hereinafter described in a preferred example of embodiment with reference to the accompanying drawing in which:

Fig 1 and Fig.2 show the device that improves the functionality and precision of similar components of the apparatus described above in isometric detached views.

Figure 3 shows the two components assembled in isometric view.

The guide tube (7), which substitutes the guide tube of the apparatus described above, has at the lower end a mounting section with a larger diameter (1) (hereinafter called receiving body (1), and one or more locating devices (3) and / or (13) which align the open-ended, detachable foot piece (5)) in line with the cutter that is sliding in the dedicated square tool holding section of the guide tube (7) to prevent alignment errors of the internal polygon to be machined.

The open-ended detatchable foot piece (5) which substitutes the close ended guide bush of the apparatus described above, has a specially shaped cylindrical guide portion whose outer dimensions correspond to the internal dimensions of the shape of the workpiece in which the internal polygon has to be cut slides on to the receiving body (1) of the guide tube (7) which has the integrated locating devices (3) alternatively (3) and I or (13) and is mounted through the openings (4) by means of several fastening devices (11) so that the forces generated during the cutting process of the internal polygons are distributed equally onto the designated surface (2) of the receiving body (1) of the guide tube (7) and onto the matching surface (16) of the foot piece (5), wherein for the production of internal polygons a foot piece (5) is used having the external dimensions that correspond to the internal dimensions of the workpiece.

Claims

The claims defining the invention are as follows:

1. A device that improves the functionality of the above mentioned apparatus to cut internal keyways in through bores and enables it to cut internal keyways, internal splines internal hexagons and other internal polygons without alignment errors in through bores and blind bores characterized in that the distance (6) between the lower end (15) of an open-ended, detachable foot piece (5) and the cutting edge of the cutting tool sliding in the square tool holding section of the guide tube (7) is reduced by at least the length of screw of the above mentioned apparatus that secures the close ended foot piece through the centre of its blind bore to the centre of the lower end of the mating guide tube which allows the internal polygon to be machined closer to the end of the bore, and one or more locating devices (3) and I or (13) which align the open ended, detachable foot piece (5) in line with the cutter that is sliding in the dedicated square tool holding section of the guide tube (7) to prevent alignment errors of the polygon to be machined.
2. An device according to claim 1), characterized in that the lower end of the guide tube (7) is provided with two sections, firstly a receiving body (1) which distributes any horizontal and vertical forces that occur during production of internal polygons equally to the designated areas (2) of the receiving body (1) and (16) of the open ended, detachable foot piece (5), precisely aligns the open ended, detachable foot piece (5) using its ingegrated positioning devices (10) and I or (14) and allows the open ended, detachable foot piece (5) to be securely mounted on it by means of the fastening devices (11), and secondly, a smaller cylindrical part (8) which slides into the mating, cylindrical opening (12) of the open ended, detachable foot piece (5).
3. A device according to an above mentioned claim, characterized in that the receiving body (1) has a segment (9) which minimizes the required recess below internal polygons in blind bores and at the same time provides sufficient space to cover the heads of the fastening devices (11) by positioning the location of the fastening devices (11) away from the centre of the receiving body (1).
4. An open ended, detachable foot piece (5) according to an above mentioned claim) having an external diameter that corresponds to the internal diameter of the bore in which the internal polygon is to be made, characterised in that the open ended, detachable foot piece (5) is precisely aligned by its integrated positioning devices (10) and / or (14) together with the mating positioning devices (3) and I or (13) of the receiving body (1) so that the cylindrical opening (12) of the open ended, detachable foot piece (5) slides over the cylindrical part (8) of the guide tube (7) until the

2018101473 10 May 2019

1 lower end (15) of the open ended, detachable foot piece (5) and (8) of the

2 guide tube (7) lie on the same plane and is mounted through the openings

3 (4) by means of several of fastening devices (11) on to the receiving body

4 (1) of the guide tube (7), that the horizontal and vertical forces generated
5 in the production of internal polygons are transmitted evenly to the surface
6 (2) of the receiving body (1) of the guide tube (7) and to the mating surface
7 (16) of the open ended, detachable foot piece (5).