WO1996006703A1

WO1996006703A1 - Combined mill/lathe machine tool

Info

Publication number: WO1996006703A1
Application number: PCT/AU1995/000535
Authority: WO
Inventors: Norman William Munns; Barry Michael Dyson
Original assignee: Norman William Munns; Barry Michael Dyson
Priority date: 1994-08-26
Filing date: 1995-08-28
Publication date: 1996-03-07
Also published as: AUPM769594A0; GB2300134B; GB2300134A; GB9610870D0

Abstract

A combined mill/lathe machine tool which allows both milling and turning operations to be performed on one machine, wherein vibrations from the working tool (20) and the workpiece are absorbed directly by the major castings forming the framework of the machine and wherein a working tool holder/adaptor is mounted: either on a milling head (18) or a ram casting (13); or an accessory mounting means (15) which is itself mounted directly on the milling heas or ram casting, and a lathe headstock (21) is mounted directly on a table/bed casting.

Description

TITLE: Combined Mill/Lathe Machine Tool

FIELD OF THE INVENTION: This invention relates to a combined mill lathe machine tool which allows both milling and tuming operations to be performed on the one machine.

BACKGROUND OF THE INVENTION: CNC milling machines and CNC lathes are quite expensive, hence it is usually not economical for a small to medium metalworking business to buy both these machine types.

A number of attempts have been made to convert conventional lathe/milling machines by adding milling machine features or building such combined devices from start. However, very few attempts have been made to convert milling machines to lathes or to build such combined devices from start

In one attempt, in US Patent No. 4,057,333 Smith and others, a lathe head and lathe tailstoc stock, when required, are mounted on the table of a numerical control milling machine. This device employs a support member for a fixed cutting tool holder, which suppoπ member spans a milling table and is spaced therefrom. This support member is fixedly secured to a stationary machine knee on which the milling table is translarionally mounted. A potential problem with this lathe device is the apparent failure to damp vibration from the cutting tool. Also the work capacity is restricted in size using this device.

It has been found that mounting the working tool directly or indirectly on the column casting of a milling machine tends to cause damage since the forces act sideways to the tool holder mounting, and the tool holder clamping forces could damage the slideways of the machine. Accordingly it is an object of this invention to provide a combined rnilJTlathe machine tool which allows both milling and turning operations to be performed on one machine and wherein vibration from the working tool and the workpiece are absorbed directly by the major castings forming the framework of the machine and lathe work size capacity is optimised.

BRIEF SUMMARY OF THE INVENTION: This invention provides a combined mill/lathe machine tool which allows both milling and turning operations to be performed on one machine and wherein vibrations from the working tool and the workpiece are absorbed directly by the major castings forming the framework of the machine wherein a working tool holder/adaptor is mounted:

either on a milling head or a ram casting; or

an accessory mounting means which is itself mounted directly on the mining head or ram casting,

and a lathe headstock is mounted directly on a table bed casting.

In an alternative embodiment the working tool may be mounted on the milling head casting via a milling spindle taper, a means being provided for locking the rotary morion of the spindle and tool.

This invention also provides a turning attachment which allows both milling and turning operations to be performed on a milling machine, wherein vibration from the working tool and the workpiece are absorbed directly by the major castings forming the framework of the machine and wherein a working tool holder/adaptor is mounted:

either on a milling head or ram casting; or The term "table/bed" is used to indicate that the lathe device may be used on either "table" or "bed" type milling machines.

The operation of the machine tool according to the invention is preferably controlled by computer means (NC or "numerically controlled" or CNC or "computer numerically controlled")- The various axes of movement have conventional nomenclature. Thus:

(a) longitudinal movement along the table/bed is:

mill: to the left is "X" +ve; lathe: to the left is "Z" -ve;

(b) transverse movement with respect to the table/bed is:

mill: to the front is "Y" + ve; lathe: to the front is "X" -ve; and

(c) vertical movement with respect to the table/bed is:

mill: downwards is "Z" - ve; lathe: movement disabled.

The headstock may be modified to provide so-called "4th axis" operation. Thus milling and/or turning operations may be performed on a workpiece, the workpiece being worked with respect to an axis longitudinally through the table bed.

The headstock and tailstock may be transposed with respect to the table bed as required. Referring now to the accompanying drawings, a machine tool 10 according to the invention comprises a base and column 11. This column supports an intermediate swivel and slide adaptor 12, which supports a horizontally disposed milling ram casting 13. Milling ram casting 13 terminates at a swivel 14.

An accessory mounting lug 15 is connected rigidly or cast as part of a second end of milling ram casting 13.

Turning now to the working tool side of the machine tool 10, reading from the top of the drawing, a motor 16 is mounted on a motion speed control means 17 which is supported by milling head assembly 18. Number 181 indicates a milling spindle taper forming pan of milling head assembly 18 also mounted at swivel 14. A lathe tool adaptor 19 is connected to the milling head assembly 18 and itself supports the lathe tool 20.

Below and to one side of lathe tool 20 is a lathe headstock 21 mounted on a table/bed 22. A lathe spindle motor 23 is mounted on the lathe headstock casting.

Manual switch 24 is activated to switch electric power between the milling spindle motor 16 and the lathe spindle motor 23 as required.

A motor 25 is mounted on the side of a knee means 26. This motor controls the transverse movement of the table/bed by means of a leadscrew.

Another motor 27 is connected to the table 22 at one end. This motor controls the longitudinal movement of the table/bed by means of a leadscrew. The whole table/bed 22 and knee 24 assembly is adjustable in height using vertically oriented screw means 29. Table bed motors 26 and 27 are controlled by the CNC controller 28 and hence the motion of the table/bed 22 may be controlled. Controller 28 also controls relanve motion between spindle motors 16 or 23.

Numeral 30 indicates an alternative position for the tool adaptor 19 and the lathe tool 20.

Numeral 31 refers to a lathe tailstock.

In another embodiment, which includes a servo motor driving a lathe spindle, power is not diverted from the milling head spindle but is rather supplied separately by a servo controller.

SUBSTITUTE SHEET (HOLE 26)

Claims

CLAIMS :

1. A combined rnilJTlathe machine tool which allows both milling and turning operations to be performed on one machine, wherein vibrations from the working tool and the workpiece are absorbed directly by the major castings forming the framework of the machine and wherein a working tool holder/adaptor is mounted:

either on a milling head or a ram casting; or

an accessory mounting means which is itself mounted directly on the milling head or ram casting,

and a lathe headstock is mounted directly on a table/bed casting.

2. A machine tool as claimed in claim 1, wherein the major castings forming the framework of the machine tool comprise:

a. a milling head or ram casting mounted on

b. a machine base and column casting, which supports

c. a sideways projecting knee casting, which supports

d. a table casting, which supports

e. a lathe headstock casting.

3. A machine tool as claimed in claim 2, wherein the lathe headstock is fabricated.

4 A machine tool as claimed in claim 1, wherein its operation is controlled by computer means.

5. A machine tool as claimed in claim 1, wherein the headstock may be modified to provide so-called "4th axis" operation, wherein milling and/or turning operations may be performed on a workpiece, the workpiece being worked with respect to an axis longitudinally through the table/bed.

6. A machine tool as claimed in claim 1, wherein the working tool may be mounted on the milling head casting via a milling spindle taper, a means being provided for locking the rotary motion of the spindle and tool.

7. A turning attachment which allows both milling and πirning operations to be performed on a milling machine, wherein vibration from the working tool and the workpiece are absorbed directly by the major castings forming the framework of the machine and wherein a working tool holder/adaptor is mounted:

either on a milling head or ram casting; or

an accessory mounting means is itself mounted directly on the milling head or ram casting,

and a lathe headstock is mounted directly on a table/bed casting.

8. A turning attachment as claimed in claim 7, which comprises a lathe headstock, a lathe tool holder and a lathe tool adaptor.