GB2265326A

GB2265326A - Lathe

Info

Publication number: GB2265326A
Application number: GB9301388A
Authority: GB
Inventors: Jorg Sellner; Rudolf Siegwart; Robert Binder; Hans Ganglberger
Original assignee: Steinel Voest Alpine GmbH; Voest Alpine Steinel GmbH
Current assignee: Steinel Voest Alpine GmbH; Voest Alpine Steinel GmbH
Priority date: 1992-03-23
Filing date: 1993-01-25
Publication date: 1993-09-29
Also published as: DE4302655A1; FR2688725A1; GB9301388D0; ATA58392A

Description

1 2265326 L A T E E

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a lathe comprising a headstock and a work spindle, which is rotatably mounted in the headstock and carries detachably mounted work-holding means.

2. Description of the Prior Art

Because lathes are usually employ- ed to machine workpieces having rotational symmetry, the work-holding means provided on lathes are usually designed to machine such parts to be turned. To permit a workpiece which has been fixed in a given position to be machined not only by means of lathe tools but also with drilling and millling tools, it is known (from Austrian Patent Specification 378,710) to provide two cross-dides, one of which carries a turret head and the other of which carries a tool post provided with a drivable tool spindle so that different lathe tools may be used, which are mounted on the turret head, and it is independently possiDle to use milling and drilling tools, which are mounted on the tool post provided with the drivable tool spindle. In conjunction with the versatile use of tools which is thus permitted it is desirable tomachine even workpieces which have no rotational symmetry, such as cubic workpieces, although this would require special work-holding means. It is known to hold workpieces having no rotational symmetry in machining centers by means of pallets, which are fixed to a deck of the machine tool. But all efforts to use such pallets for holding tools instead of the work-holding means of a lathe, which usually consist of a chuck, have not been promisidg because the mekns f or rotatably mounting the work spindle in the headstock are not de#3ned for to withstand the forces such as are to be expected in the machining of cuDic workpieces.

SUMMARY OF THE INVENTION

For this reason it is an object of the invention so to improve by the use of simple structural means a lathe which is of the kind described first hereinbefore thqt even workpieces having no rotational symmetry, such as cubic workpieces, can be machined without a restriction by means of the tools which are available.

The object set rth is accomplished in accordance with the invention in that a carrying -L ring, which is coaxial to the works-Dindle, Js rotatab-- a pallet for carrying work-holding means.

ly mounu-i-..,., Because a separate carrying ring is provided and is rotatably mounted on the headstock independently of the work spindle, loads which are due to the machining forces to ce expected can simply oe taken up oy the machine Ded via the headstock because the bearing means for the carrying --inG can readily be designed to take up such loads. The holder for detachably mounting a pallet may be connected to the carrying ring in a conventional manner and may con- sist of conventional quick-action holding means for the pallet, which is preferably mounted on the holdee provided on the carrying ring after the workpiece has been fixed. It will be understood that the workholding means for holding parts to be turned must be removed from the work spindle before the pallet is fixed.

The carrying ring may be rotated by various drive means. In a particularly simple design the carrying ring is connected to the holder for the pallet by means of an annular gear which is connected to the carrying ring, so that the workpine to be machined can be rotated independently of the work spindle. To permit the use of such means for directly driving the carrying ring for the pallet also for the control of the movement about the axis which is generally designated as the C axis and is defined by the axis of the work spindle, the carrying ring may be adapted to oe non-rotatably coupled to the work spindle by an index pin. which extends into an index recess.

BRIEF DESCRIPTION OF MEE' DRAWING

FiGuze _ is a schemarsic top plan view showing the ine-lined bed of a lathe in accordance with the invention.

Figure 2 is an end elevation showin,,that lathe as viewed on the headstock when the tailstock has been removed.

Figure 3 is an enlarged axial sectional view showing the headstock.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The illustrated lathe essentially consists of an inclined bed 1, on which a carriage 2 is slidably mounted in a guide 3. The carriage 2 is adapted to be driven by a feed screw, nou shown, and is provided with two guides 4 and 5, which are at right angles to the guide 3 and serve to guide two crossslides 6 and 7, which also can be adjusted by means of respective feed screws. That of the cross-slides 6 and 7 which is nearer to the headstock 8, namely, the crossslide 6, carries a turret head 9, which is provided with lathe tools 10. The turret head 9 can be rotated by drive means 11 to effect a quick tool change.

The other cross-slide 7 faces the tailstock 12 and adjacent to its end face facing the main axis of the lathe carries a tool post 13, which is provided with a driven tool spindle, so that machining maybe ef f ected by means of lathe tools as well as with a drilling or milling tool without a need for fixing the workpiece by different means. The arrangement is such that the tool post 13 is mounted to be rotatable about a pivotal axis which is at right angles to the main axis of the lathe and to the guide If or the cross- slide 7 so that the tool post is movable from the position shown in Figure 1 at right angles to the main axis of the lathe to both sides to a position in which the tool post is parallel to the main axis so that the drilling and milling tools can be universally used. Besides, said angular adjustment of the tool Post 13 permits the tool post 13 to be coupled to a tool-changing device 15, which is connected to a tool magazine 14 and by means of which the dr:Lilling and milling tools can be replaced simply and quickly.

To permit the drilling and milling tools to be used not only for machining turned parts, which are usually fixed in a chuck 16 in a position in wnich they can be machined, it is possible to provide the headstock 8 with a pallet for carrying work-holding means rather than with the chuck 16. For that Purpose a carrying ring 18, which is coaxial to the work spindle 17, is rotatably mounted on the headstock 8 and is connected to an annular gear 19, through the intermediary of which the ring 18 can be driven by means of a pinion, not shown. The carrying ring 18 is supported on the headstock 8 by a rollingelement bearing 20 and is provided with a holder 21 for detachably mounting a pallet 22, which is fitted on a mounting.;one 23 of the carrying ring and is clamped in position by means of radial chucking wedges 24, which are movable in mating recesses 25 of the pallet and pull the latter axially onto the mounting cone. Pistons 26, which are acIpted to oe supplied with a pressure fluid,are provided for the actuation of the chucking wedges 24.

0 13 A conventional chuck 16 is similarly fixed to the work spindle 17, which for that purpcse carries chucking wedges 27, whiah are movable in recesses 28 of the chuck 16 so that the chuck 16 is pulled onto the mounting cone 29 of the work spindle 17.

To permit a rotation of the work spindle 17 by means of the drive for the annular gear 19 and to provide an exact indication of the angular position of the workpiece, the carrying rirg 18 may be adapted to be non-rotatably coupled to the work spindle 17 by means of an index pin 31, which can be adjusted by pressure fluid-operated means and v extends into an indexing recess 30.

If a workpiece is to be turned, that work- piece will be inserted into the chuck 16. Fcr a machining of a cubic workpiece the chuck 16 must be removid and alallet carrying work-holding means must be clamped on the carrying ringi this can simply and quickly oe effected by means of the chucking wedges 24. Because the workpiece should be fixed to the pallet 22 oefore the latter is mounted, it is recommended to change the pallet with the workpiece fixed thereto as is indicated in phantom in Figure 2. The workpime is fixed to a prepared pallet in a frame, not shown in detail, outside the lathe and together with the pallet is gripped by a gripping arm 32 and is supplied to the headstock 8 in proper position for being fixed.

1 7 -

Claims

1. A lathe comprising a headstock and a work spindle, which is rotatably mounted in the Ieadstock and carries detachably mounted workholding means, characterized in that a carrying ring, which is coaxial to the work spindle, is rotatably mounted on the headstock and provided with a holder for detachably mounting a pallet for carrying workholding means.

2. A lathe according to claim 1, characterized in that the carrying ring is connected to the holder for the pallet by means of an annular geary which is connected to the carrying ringg,

3. A lathe according to claim 1 or 2.

characterized in that the carrying ring is adapted to be non-rotatably coupled to the work spindle by an index pin, which extends into an index recess.

4. A lathe, substantially as described hereinbefore with reference to and as shown on the drawing.