GB2054435A

GB2054435A - Tool holder for a machine tool

Info

Publication number: GB2054435A
Application number: GB8022158A
Authority: GB
Original assignee: HERBERT Ltd ALFRED
Current assignee: HERBERT Ltd ALFRED
Priority date: 1979-07-20
Filing date: 1980-07-07
Publication date: 1981-02-18
Also published as: GB2054435B

Abstract

A tool holder 10 for a turning machine has a pair of tool receiving sockets adapted to receive respective tools 8 arranged so that the tools may, in use, be brought successively to a workpiece axis-based position to perform a machining operation independently of any other tool in the holder. The holder is mounted on a turret mounted on a cross-slide on a saddle movable along or parallel to the machine spindle axis. Successive machining operations may be performed by the tools of a holder by moving the turret radially by means of the cross-slide. <IMAGE>

Description

SPECIFICATION This invention relates to a tool holder for mounting on a tool carrier of a turning machine capable of movement in at least two axes, one of which is along or parallel with the spindle axis of the machine and the other at right angles thereto. The invention also embraces a turning machine incorporating such a tool holder.

According to the invention, a tool holdeer has means for fixing it to a tool carrier, and a plurality of tool retention means arranged so that when the holder containing a plurality of tools is installed in turning machine, the tools may be brought successively to a centre-based or generally centre-based operative position, to perform a machining operation independently of any other tool in the holder.

From another aspect of the invention, a turning machine has a tool carrier capable of movement in at least two axes, a first of which is along or parallel with the spindle axis of the machine and the second of which is at right angles thereto, the tool carrier having mounted thereon a tool holder having a plurality of tool retention means arranged so that the tools may be brought successively to a centre-based or generally centre-based position by movement of the tool carrier along said second axis whereby each tool when in said position may perform a machining operation independently of any other tool in the holder.

In one convenient practical form of the machine tool, the tool carrier is an indexable turret and the tool retention means of said holder extend radially of the indexing centre of the turret.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 7 is a general view of a turning machine of the invention, and Figure 2 is a perspective view, to an enlarged scale, of a tool carrier of the machine tool shown in Figure 1.

Referring to the drawings, these show an automatic machine tool having a bed 1 mounting a saddle 2 which carries a cross slide 3. The cross slide carries a rotary indexable turret 4 together with the necessary drive and indexing mechanism 5 for the turret.

Workpieces to be machined are mounted in a chuck 6, in conventional manner, and the usual N.C. or other control system for controlling automatic machining operations is located in a cabinet 7. The turret 4 carries a plurality of tools 8 of various kinds mounted in pairs in tool holders 9 secured to appropriate faces of the turret.

The turret is shown in greater detail in Figure 2 and as having four tool holders 9, each having tool retention means in the form of a pair of sockets in which are mounted respective tools 8 disposed radially of the centre of rotation of the turret. Each of the tool holders 9 includes a body 10 and a base 11 whereby the holder is releasably secured to the turret by means of bolts 12. The base may have any convenient means, such as a dovetail formation, for interconnection with the turret face which would have a complementary formation. All of the tools in the double tool holders 9 are of the centre-based type, i.e. they operate along or parallel to the spindle axis of the machine tool.The turret carries further tool holders 13 shown containing turning tools 14 arranged to operate longitudinally or transversely of the spindle axis, although it will be understood that the turret may have a double holder on each tool face, if required.

In order to perform a centre-based or generally centre based machining operation using the turret of Figure 2, the turret is indexed to bring one of the double tool holders into an operative position opposite to the machine spindle and the transverse slide is operated to bring either the radially outer or inner tool of that holder to the correct position relative to the spindle centre. The saddle is then traversed to enable the tool to perform the necessary machining operation, following which it is possible to use the other tool in the same holder by again using the transverse slide to bring that tool into the appropriate centre-based or generally centre based position.

The saddle 2 is withdrawn to the extent necessary to enable the appropriate transverse movement of the turret to take place, following which the saddle moves once again to perform a further centre-based or generally centre-based machining operation. It will be understood that, in practice, the spacing of the tools in each holder 10 is such that when one tool is in its working position on or adjacent to the workpiece centre, the other tool clears the outer diameter of the workpiece.

As an alternative to the radial mounting of the tools in the holders 10, it would be possible to space the tools angularly in the holders. This would, however, necessitate extra indexing capability in the machine tool, e.g. along a third axis at right angles to the other two axes to permit full use to be made of the tools.

It will be understood that the term "tool" used herein is intended to cover any item of equipment normally held in a tool holder for centre-based operations, such as a bar grabber or bar stop, as well as various types of cutting tools. Each holder may contain three or more tools instead of the pairs of tools as illustrated. Although tools such as drills and taps are strictly centre-based, the tool holder of the invention may be used with tools such as boring bars which can be regarded as generally centrebased.

The principal advantages of the invention are that it provides the possibility of considerable extra tooling capacity whilst retaining a standard turret and drive mechanism. The amount of tool changing required for a given machining operation is also likely to be reduced.

As a practical matter, the tool centres of the tools in each multi-tool holder are preferably spaced so as to be equi-distant from the centre of a turning tool e.g. 14 so that cross-traversing is minimised when moving from a centre based to a turning tool.

The various turret indexing and slide movements required to enable the various tools of both types of holder to be used in a predetermined sequence, including successive use of tools in the multi-tool holders, may be carried out as part of an automatic machine programme under N.C. or other control.

Claims

1. Atool holder having meansforfixing ditto a tool carrier, and a plurality of tool retention means arranged so that when the holder containing a plurality of tools is installed in turning machine, the tools may be brought successively to a centre-based or generally centre-based operative position, to perform a machining operation independently of any other tool in the holder.

2. Atool holder according to Claim 1 wherein the tool retention means are tapered sockets adapted to receive complementary tool shanks.

3. A tool holder according to Claim 1 or Claim 2 provided with a retaining formation for interengagemenu with a complementary formation on the tool carrier.

4. Aturning machine having atool carrier capable of movement in at least two axes, a first of which is along or parallel with the spindle axis of the machine and the second of which is at right angles thereto, the tool carrier having mounted thereon a tool holder having a plurality of tool retention means arranged so that the tools may be brought successively to a centre-based or generally centre-based position by movement of the tool carrier along said second axis whereby each tool when in said position may perform a machining operation independently of any other tool in the holder.

5. A turning machine according to Claim 4 wherein the tool carrier is an indexable turret and the tool retention means of the holder extend radially of the indexing centre of the turret.

6. Aturning machine according to Claim 4 or Claim 5wherein the turret is carried on a cross-slide itself mounted on a saddle movable along or parallel to the machine spindle axis.

7. A tool holder substantially as hereinbefore described with reference to the accompanying drawings.

8. Aturning machine substantially as hereinbefore described with reference to the accompanying drawings.