GB2284169A

GB2284169A - Auxiliary Machine Tool

Info

Publication number: GB2284169A
Application number: GB9323420A
Authority: GB
Inventors: John C Payne
Original assignee: Payne F J & Son Ltd
Current assignee: Payne F J & Son Ltd
Priority date: 1993-11-12
Filing date: 1993-11-12
Publication date: 1995-05-31
Anticipated expiration: 2013-11-12
Also published as: GB2284169B; GB9323420D0

Abstract

The auxiliary machine tool is for attachment to a larger machine tool, such as a lathe, and comprises a support section 4 on which a chuck is mounted for holding a tool 22 and drive means for rotating the chuck. The auxiliary tool also comprises a carrier section 3 with attachment means 1 for securing it to a tool holder 20 of the larger machine. The carrier section 3 is slidably mounted with respect to the support section 4 and provides an infinitely variable adjustment of the support section 4 relative to the carrier section 3 in a direction at right angles to the axis of the chuck so as to provide fine adjustment of the position of the chuck relative to the larger machine. The auxiliary tool can also be mounted with the axis of rotation of the chuck inclined to the larger machine. <IMAGE>

Description

AUXILIARY MACHINE TOOL This invention relates to an auxiliary machine tool. In particular, it is concerned with an auxiliary machine tool for attachment to a larger machine tool, such as a lathe, so as to make it possible to carry out additional operations on a workpiece mounted conventionally on the larger machine tool.

In British Patent specification GB2230985, there is described an auxiliary machining device comprising: a first part whereby the device can be secured to a conventional tool holder of a machine tool; a second part; means whereby the second part can be secured to the first part in one of a predetermined plurality of fixed locations prior to securing the device to a larger machine tool; a drive unit mounted on the second part comprising an electric motor and a speed controller for the motor whereby output shaft speed can be varied, the torque output of the motor being substantially independent of output shaft speed; and a tool holder adapted to be driven by way of the output shaft so as to rotate a cutting tool retained by the tool holder.

The description of the known auxiliary machinery device described in GB2230985 is hereby incorporated in this specification.

This auxiliary machining device was designed for use with a lathe having a toolpost mounted on a cross-slide where the toolpost incorporated means for displacing the device in a vertical direction relative to the bed (typically a Dickson tool post). If this direction is designated as the Z axis of a set of rectangular co-ordinates, the cross-slide can also be displaced along the bed in a horizontal X axis by a first control wheel and along a horizontal Y axis at right angles to both the X axis and Z axis by a second control wheel. However, the extent of vertical adjustment along the Z-axis is usually limited and on less expensive machines, as used by model engineers for example, there is often no provision at all for adjustment in the vertical direction.

According to the present invention there is provided an auxiliary machine tool for attachment to a larger machine tool, such as a lathe, the auxiliary machine tool comprising a support section on which is mounted a chuck for holding a tool and drive means for rotating the chuck about an axis, the auxiliary machine tool also comprising a carrier section having attachment means for securing the auxiliary machine tool to a tool holder of the larger machine, the carrier section being slidably mounted with respect to the support section and being provided with adjustment means for providing infinitely variable adj ustment of the support section relative to the carrier section in a direction at right angles with the said axis so as to provide fine adjustment of the position of the chuck relative to an axis of the larger machine, the attachment means being adapted so that the carrier section can be secured to a tool holder in a plurality of positions so as to provide a gross adjustment of the position of the auxiliary machine tool relative to the said axis of the larger machine and being adapted so as to enable the auxiliary machine tool to be mounted so that the said axis of rotation of the chuck is inclined to the said axis of the larger machine.

Other features of the invention will be apparent from the following description and the subsidiary claims of the specification.

The invention will now be further described merely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of one embodiment of a device according to the invention; Figure 2 is an end view of the device shown in Figure 1; and Figure 3 shows the device attached to the tool post of a lathe.

The Figures show a device with a chassis comprising a first part in the form of a bar 1 for securing the device to a tool holder 20 of a lathe and a second part made up of a carrier section 3 and a support section 4.

A drive unit 5 is rigidly secured to the support section 4. The drive unit 5 comprises an electric motor 6 arranged to drive a shaft 7, which passes through the drive unit 5, the support section 4 and the carrier section 3 to rotate a chuck 8 about an axis T, the drive being transmitted from the motor 6 to the shaft 7 by pulley wheels 9 and 10 and a belt drive 11. As shown in the Figures, the drive unit 5 is mounted in line with the chuck 8 with the motor 6 mounted above the drive shaft 7. The auxiliary tool is thus relatively narrow. The drive unit 5 also houses a speed adjustment mechanism (not shown) which is controlled by a control knob 12. An on-off switch 13 is also provided together with a forward-reverse switch 14 (which is positioned so that it can only be operated when the on-off switch 13 is in the 'off' position).

The carrier section 3 is slidably mounted on the support section 4 so that its position along an axis S can be adjusted by turning adjustment knob 15. The axis S lies at right angles to the axis T about which the chuck 8 rotates. Adjustment of the carrier section 3 is effected by way of a screw threaded shaft 3A which projects from the support section 4 and to which the a control knob 15 is attached.

Rotation of the control knob 15 thus draws or pushes the carrier section 3 along axis S relative to support section 4 to provide infinitely variable adjustment of the carrier section 3 in the direction of the axis S.

The carrier section 3 is of substantially rectangular section 3 and is slidably mounted on the support section 4 by means of dovetailed slides or other forms of slide, eg a square cornered slide. The carrier section 3 thus straddles the drive shaft 7 which extends from the drive unit 5 to the chuck 8. This provides a compact construction in which the carrier section 3 is of substantially similar width to the support section 4 in a direction at right angles to the axis T of the chuck 8 and at right angles to the axis of the screw threaded shaft 3A.

As shown in Figure 1, the carrier section 3 is provided with two pairs 16, 17 of threaded holes. It is also provided with a pair of arcuate slots 18 in which securing nuts (not shown) can be slidably mounted.

The bar 1 is provided with a pair of screw threaded attachment means 19 which may be screwed into respective holes 16, 17 or into securing nuts within the slots 18. The bar 1 may therefore be secured to the carrier section 3 in a variety of different positions. When secured to either pair of holes 16 or 17, it lies parallel to the axis T. However, when secured to slidable nuts within the slots 18 it can be positioned at an angle to the axis T (as shown in Figure 1). Further pairs of screw threaded holes (not shown) may also be provided on the opposite side of the carrier section 3 to that shown in Figure 1.

In use, the auxiliary machine tool is secured to the tool holder 20 of a lathe 21 as shown in Figure 3 by mounting the bar 1 within the tool holder 20 and a tool 22, for example a milling cutter, is secured in the chuck 8. If the bar 1 is secured so as to lie parallel to the axis T, then axis T lies parallel to the horizontal axis X. However, if the bar is inclined to the axis T, the axis T will be similarly inclined to the horizontal axis X.

Coarse adjustment of the height of the tool 22 relative to a workpiece 23 held in the lathe chuck 24, ie in the direction of the Z-axis, is effected by attachment of the bar 1 to the appropriate set of screw threaded holes 16, 17 or nuts within the arcuate slots 18. However, fine adjustment in the direction of Z-axis is effected by adjusting the position of the carrier section 3 relative to the support section 4 of the tool by rotating the adjustment knob 15. This adjustment preferably provides for about 40 mm of adjustment in the direction of the Z-axis. The adjustment knob 15 may be provided with a calibrated scale to allow for accurate and reproducible adjustment of the position of the tool to within +0.025mm.

By providing separate coarse adjustment and fine adjustment in the vertical direction in this way, it will be appreciated that the infinitely variable adjustment need be provided over only a relative small distance as indicated above.

It will be appreciated that when the bar 1 is secured to either of the sets of holes 16 or 17 so that it lies parallel to the axis T adjustment of knob 15 will move the tool in the direction of the Z-axis. However, if the bar 1 is secured to the carrier section 3 at an angle to the axis T by way of nuts in the arcuate slots 18, the axis T will be inclined to the horizontal and adjustment of the knob 15 will move the tool in a direction similarly inclined to the vertical axis Z (although this movement will always have a component in the direction of the Z-axis).

The auxiliary tool, and the tool 22 secured thereto, may, of course, be moved in the directions of the X and Y axes by adjustment of the lathe tool holder 20 in the conventional manner. Furthermore, it will be appreciated that the bar 1 can be secured to the tool holder 20 of the lathe so that it extends in the direction of the Y-axis rather than the X-axis. The axis T of the chuck 8 will then be at right angles, ie radially, to the axis of the lathe (which lies parallel to the X-axis).

The auxiliary tool holder can thus be turned through 900 in the horizontal plane by the simple expedient of adjusting the mounting position of the bar 1 within the tool holder 20 and securing the bar 1 on the opposite side of the carrier section 3. Additional flexibility in the mounting of the auxiliary tool is provided by the ability to secure the bar 1 to either side of the carrier section 3 by providing screw threaded holes on both sides thereof as mentioned above.

It will thus be seen that the arrangement described provides for vertical adjustment of the tool 22 whether or not the tool holder 20 of the lathe provides for adjustment in this direction. The auxiliary tool is thus suitable for use both on larger, commercial lathes and on the less expensive type of lathes used by model makers and confers the advantage of controlled adjustment in the direction of the Z-axis, or at an angle thereto, on all types of lathe.

When the auxiliary tool is secured to the lathe tool holder with the axis T parallel to the horizontal, it can be used to carry out a wide variety of machining operations on the workpiece 23, such as milling flats on a workpiece to convert round stock to a square, or hexagonal section, or the drilling and tapping of cross holes in the workpiece 23 and the drilling of holes on a pitch circle diameter. When the auxiliary tool is mounted with the axis T inclined to the horizontal, it can be used to cut helix angles within or upon a workpiece 23 held in the lathe chuck 24.

The auxiliary tool described above thus enables milling operations to be carried out on a workpiece held in a lathe. It can be quickly and easily attached to the lathe and due to a combination of the manner of attachment thereto and the provision for infinitely variable adjustment in the vertical direction, it can be quickly and easily adjusted to a wide range of positions and orientations with respect to the workpiece to allow a wide range of milling operations to be carried out. The auxiliary tool is also of compact design so as to minimise the risk of fouling the lathe or workpiece when adjusted to the said wide range of positions and orientations yet is of robust construction.

Claims

1. An auxiliary machine tool for attachment to a larger machine tool, such as a lathe, the auxiliary machine tool comprising a support section on which is mounted a chuck for holding a tool and drive means for rotating the chuck about an axis, the auxiliary machine tool also comprising a carrier section having attachment means for securing the auxiliary machine tool to a tool holder of the larger machine, the carrier section being slidably mounted with respect to the support section and being provided with adjustment means for providing infinitely variable adjustment of the support section relative to the carrier section in a direction at right angles with the said axis so as to provide fine adjustment of the position of the chuck relative to an axis of the larger machine, the attachment means being adapted so that the carrier section can be secured to a tool holder in a plurality of positions so as to provide a guess adjustment of the position of the auxiliary machine tool relative to the said axis of the larger machine and being adapted so as to enable the auxiliary machine tool to be mounted so that the said axis of rotation of the chuck is inclined to the said axis of the larger machine.

2. An auxiliary machine tool as claimed in claim 1 in which the attachment means comprises a bar adapted to be held by the tool holder of the larger machine and a plurality of attachment locations on the carrier section for attaching the bar thereto.

3. An auxiliary machine tool as claimed in claim 2 in which attachment locations are provided on more than one side of the carrier section.

4. An auxiliary machine tool as claimed in claim 2 or 3 in which arcuate attachment locations are provided on the carrier section to enable the bar to be attached thereto at a selected angle relative to the said axis of rotation of the chuck.

5. An auxiliary machine tool as claimed in any proceeding claim in which the adjustment means comprises a screw threaded shaft secured to the support section and a rotatable adjustment knob mounted on the carrier section into which the shaft is threaded, whereby rotation of the adjustment knob draws or pushes the carrier section along an axis parallel to that of the screw threaded shaft relative to the support section.

6. An auxiliary machine tool as claimed in claim 5 in which the axis of rotation of the chuck passes through the carrier section.

7. An auxiliary machine tool as claimed in claim 6 in which the carrier section and the support section are of substantially similar width in a direction at right angles to the axis of rotation of the chuck and at right angles to the axis of said screw threaded shaft.

8. An auxiliary machine tool as claimed in any preceding claim in which the drive means comprises an electric motor.

9. An auxiliary machine tool as claimed in claim 8 comprising speed control means for adjusting the speed at which the chuck is rotated by the electric motor.

10. An auxiliary machine tool substantially as hereinbefore described with reference to the accompanying drawings.

11. A machine tool, for example a lathe, with an auxiliary machine tool as claimed in any preceding claim mounted thereon.

Amendments to the claims have been filed as follows 1. An auxiliary machine tool for attachment to a larger machine tool, such as a lathe, the auxiliary machine tool comprising a support section on which is mounted a chuck for holding a tool and drive means for rotating the chuck about an axis (T), the auxiliary machine tool also comprising a carrier section having attachment means for securing the auxiliary machine tool to a tool holder of the larger machine, the tool holder being adjustable along mutually perpendicular axes (X and Y) of the larger machine by adjustment means provided on the larger machine, the carrier section being slidably mounted with respect to the support section and being provided with adjustment means for providing infinitely variable adjustment of the support section relative to the carrier section in a direction (S) at right angles to the said axis (T) so as to provide fine adjustment of the position of the chuck relative to an axis (X) of the larger machine, the attachment means being adapted so that the carrier section can be secured to a tool holder in a plurality of positions so as to provide a gross adjustment of the position of the auxiliary machine tool in the said direction (S) relative to the said axis (X) of the larger machine and being adapted so as to enable the auxiliary machine tool to be mounted so that the said axis of rotation (T) of the chuck is inclined to the said mutually perpendicular axes (X and Y) of the larger machine.

4. An auxiliary machine tool as claimed in claim 2 or 3 in which arcuate attachment locations are provided on the carrier section to enable the bar to be attached thereto at a selected angle relative to the said axis of rotation (T) of the chuck.

5. An auxiliary machine tool as claimed in any preceding claim in which the adjustment means comprises a screw threaded shaft secured to the support section and a rotatable adjustment knob mounted on the carrier section into which the shaft is threaded, whereby rotation of the adjustment knob draws or pushes the carrier section along an axis (S) parallel to that of the screw threaded shaft relative to the support section.

6. An auxiliary machine tool as claimed in claim 5 in which the axis of rotation (T) of the chuck passes through the carrier section.

7. An auxiliary machine tool as claimed in claim 6 in which the carrier section and the support section are of substantially similar width in a direction at right angles to the axis of rotation (T) of the chuck and at right angles to the axis (S) of said screw threaded shaft.