GB2135619A

GB2135619A - Indexable turret for a machine tool

Info

Publication number: GB2135619A
Application number: GB08404266A
Authority: GB
Inventors: Walter Reusch
Original assignee: Sauter Feinmechanik GmbH
Current assignee: Sauter Feinmechanik GmbH
Priority date: 1983-02-19
Filing date: 1984-02-17
Publication date: 1984-09-05
Also published as: DE3305845C2; GB8404266D0; IT8467155A0; IT1179585B; FR2541153A1; FR2541153B1; DE3305845A1

Abstract

A turret for a machine tool, more especially a lathe, has an indexable carrier (2) which has a plurality of angularly equally spaced supporting devices, each of which have a locating bore (3). The supporting devices each comprises a drive wheel 4 and a driving gear (21), which is drivable from a driving motor (18) and is arranged in the same plane as the drive wheels 4 of the supporting devices. The driving gear and the drive wheels are rotatably mounted in a housing body (25), which connects them, and are driven by a flexible drive member (32). <IMAGE>

Description

SPECIFICATION Improvements in or relating to a turret head for a machine tool The invention relates to a turret head as described in the introductory part of Claim 1.

A known turret head of the afore-mentioned kind, whose holding devices serve for holding workpieces, a tool carrier and the driving device necessary for this purpose form part of a machine tool. On the known turret head, the holding device is provided at one end of a driving spindle which is mounted in the central zone and at the other end of which there is attached a gear so as to be secured against rotation. However, this gear is not arranged in an overhung position but is also mounted at its end that is directed away from the holding device, there being coaxially arranged between the drive wheel and the bearing a working cylinder which serves for operating the holding device by means of a piston rod which penetrates the spindle (US PS 2 055 434).

The task underlying the invention is to provide a simply designed turret head whose driving device, which is easily accessible from the outside for the tools of the tooling equipment, requires little space inside the turret head. According to the invention, this problem is solved by the features given in the characterising part of Claim 1. The arrangement of the holding devices and the drive wheels on the same side of the machine results in a considerable saving of space. The holding devices and the drive wheels consist of parts which can be produced in a relatively simple manner and can be easily exchanged so that the turret head according to the invention is easy to maintain.There is unhindered access to the front end of the tool carrier of the turret head so that it is possible to exchange without any problem a tool or a tool supporting device for another tool or for another tool supporting device.

In order to guide the flexible drive member adequately, there suffices an arrangement as described in the features of Claim 2.

The drive member can be tensioned in a simple manner by making use of the features of Claims 3 and/or 4.

The features of Claims 5 and possibly 6 refer to a preferred further development of the invention in this connection.

The features of Claim 7 are directed at a spacesaving design of the drive wheel which is provided with a toothed rim on its circumference.

A compact constructional form is brought about by the features of Claim 8.

The features of Claims 9 and 10 relate to a preferred constructional form of the turret head.

Further advantages will result from the other claims, the description and the drawings, in which a turret head is diagrammatically illustrated as an exemplified embodiment of the subject matter of the invention. In the drawings Figure 1 shows a section along the line I-I in Figure 2, Figures 2a and 2b each show a section along the line Il-Il in Figure 1, Figure 3 shows a diagram corresponding to Figures 2a and 2b on a different scale, Figs. 4 and 5 each show a section from Fig. 1 with a different sectional run and on a different scale.

In a housing 1, a disc-shaped tool carrier 2 is drivable step by step around its axis by means of a known 'per se' indexing mechanism not shown.

The tool carrier 2 has twelve seating bores which are evenly arranged in a circle and of which only the seating bores 3 and 3f are shown in Figure 1.

Every second of the seating bores is identically designed and serves for seating a bearing part for a rotatable tool which may form part of a tool arrangement and whose driving shank 38, which is shown in dash-dotted lines and comprises a coupling end, is connectable to a clutch part 4 (Figures 1 and 5).

The clutch part 4 serves as the drive wheel for the tool comprising the driving shank 38. The clutch part 4 is sleeve-shaped and has in its base a clutch recess 5 which is non-circular, more especially sequare in cross-section, and into which the end of the driving shank 38 can be inserted and from which it can be removed.

The clutch part 4 is rotatably mounted by means of antifriction bearings 6 on a bearing bush 7, which engages in the seating bore 3 and is fixedly connected to the tool carrier 2 and has a through bore, and is held on the side of the tool carrier on the two antifriction bearings 6 by means of a ring-shaped holding piece 8. On its side that is directed away from the tool carrier 2, the clutch part 4 is covered by means of a cover disc 9. The gap between the clutch part 4 and the cover disc 9 is sealed by means of a sealing ring.

The clutch part 4 carries teeth 10 on its outside and is designed in the manner of a gear. With every second of the seating bores 3 there is associated a clutch part 4 and the parts 5 to 10 appertaining thereto.

On the side of the clutch part 4, the tool carrier 2 has a stepped part 11 which is surrounded by a ring element 12 which, in troughs, receives the clutch part 4 sections directed towards the axis of the tool carrier 2. The gap between the stepped part 11 of the tool carrier 2 and the ring element 12 is sealed by a sealing ring 13 which has been inserted into a slot in the stepped part 11. On the side of the ring element 12 that is directed away from the tool carrier 2, there is arranged a supporting element 14 which is fixedly connected to the housing 1 and which surrounds a cylindrical portion 1 5 of the housing 1. The gap between the cylindrical portion 15 and the supporting element 14 is sealed by a sealing ring 16 and the gap between the supporting element 14 and the ring element 12 is sealed by a sealing ring 17.

On a supporting element 14, there is fastened, laterally offset, a driving motor 18 with its housing. A driving shaft 19 of the driving motor 18 is arranged so as to be axially parallel to the axis of the tool carrier 2. On the driving shaft 19 there is fitted, so as to be secured against rotation, a part 20 of a claw clutch, which part cooperates with a clutch section of a substantially coaxially arranged driving gear 21. The axes of the parts 20 and 21, which are connected together by means of the claw clutch, may be staggered relative to each other.The driving gear 21 is rotatably mounted by means of antifriction bearings 22 on an eccentric pin 23 which is rotatably mounted by means of a pivot pin 24, which is eccentrically arranged thereto, in a housing body 25 which is fastened to the supporting element 14 and which covers towards the outside the clutch parts 4 arranged on the tool carrier 2 (Figure 4). The pin 23,24 has a retaining collar 26 which is retained by a retaining element 27, which is detachably fastened to the housing body 25, on the latter. For rotating the pin 23, 24 there serves a hexagonal recess which is formed as a point of application 28 for a tool and is accessible from the outside. The driving gear 21 has retaining flanges 29 and 30 which are provided in the zone of its edges and which are secured, on their sides which are directed away from each other, by spring lock washers fitted on the driving gear 21.

A deflecting wheel 31 is rotatably mounted on the housing body 25 in an axially parallel arrangement to the tool carrier 2 (Figure 2b). The deflecting wheel 31 is located, in the same way as the driving gear 21, on an eccentric pin which is connected to a pivot pin comprising a retaining collar and which can be secured, with respect to the housing body 25, in its respective rotational position by means of a retaining element. A flexible toothed belt 32, which is not extendible in the longitudinal direction and serves as a drive member, has been looped around the deflecting wheel 31, the driving gear 21 and the clutch parts 4 which are directed away therefrom and serve as drive wheels. The eccentric pins associated with the driving gear 21 and the deflecting wheel 31 serve for tensioning the toothed belt 32.

Between respectively two clutch parts 4, which are arranged in a circle at equal intervals and which in Figures 2a and 2b are covered by the cover discs 9, 9b, 9d, 9f, 9g and 9h visible therein, there are provided seating bores 3a, 3c, 3e, 3g, 3i and 31 respectively, whose diameters may be different from the other seating bores provided therebetween and with which there is associated respectively a clutch part 4 designed as a drive wheel. In the seating bores 3a, 3c, 3e, 3g, 3i and 31 there can be accommodated tools which, as viewed in Figure 1, do not overhang the right-hand side of the disc-shaped tool carrier 2, so that the toothed belt 32 extends in a straight manner between two adjacent clutch parts 4.

Figure 3 is designed to show with the aid of a tool carrier 2a, which, differing from the aforedescribed exemplified embodiment, has four clutch parts 4 to 4c serving as drive wheels, at what points the driving gear 21 and the deflecting wheel 31 have to be arranged in order to ensure that an automatic length compensation of the toothed belt 32 occurs on a turret head on which a stationary tool is arranged between respectively two clutch parts 4. There is shown an index position in solid lines and the subsequent index position in dash-dotted lines. The clutch parts 4, 4a, 4b and 4c of the first index position have been designated 4', 4a', 4b' and 4c' in the second index position.The strand of the toothed belt 32 between the clutch part 4a and the driving gear 21 is designated 33 and the dash-dotted strand of the toothed belt 32 between the deflecting wheel 31 and the clutch part 4b' (indexed clutch part 4b) is designated 34. If the deflecting wheel 31 is missing, only the driving gear 21 a is provided, which lies on the angle bisector, designated 35, of the angle a defined by the strands 33 and 34.With identical diameters of the driving gear 21 and the clutch parts 4, 4a, 4b and 4c, the angle a is also defined by the side 36 which, in a specific index position of the turret head, extends through the axes of the driving gear 21 a and the clutch part 4a which on one side, as viewed from the driving gear 21 a, is located farthest to the outside and by the other side 37 thereof which, in a position of the turret head that follows the specific position thereof, extends through the axes of the driving gear 21 a and the clutch part 4b' which on the other side, as viewed from the driving gear 21 a, is located farthest to the outside. The strands 33 and 34 extend parallel to the sides 36 and 37 respectively of the angle a.

If, as in the exemplified embodiment shown in Figures 1 and 2, there is used a deflecting wheel 31 which has the same diameter as the driving gear 21 and the clutch parts 4, 4a, 4b and 4c, then the driving gear 21 and the deflecting wheel 31 lie on a perpendicular to the angle bisector 35 at equal intervals thereto, the strands 33 and 34 respectively being touched. If the strands 33 and 34 are touched by the driving gear 21 and the deflecting wheel 31, the diameters thereof may be different.

The ring element 12 serves for transmitting coolant from the stationary housing body 25 to the rotatable tool carrier 2.

Claims

1. A turret head for a machine tool, more especially a lathe, and provided with a rotatably mounted carrier (2), which is drivable step by step and which has rotatable holding devices (7), which are evenly distributed in a circle and are drivable by means of a flexible drive member (32), which surrounds drive wheels (4) associated with the holding devices and a driving gear (21) which is drivable from a driving motor (18), characterised in that the holding devices and the drive wheels are arranged on the same side of the turret head, and in that the drive wheel is hollow and has respectively one clutch part (5) that is associated with the holding device.

2. A turret head as claimed in Claim 1, characterised in that the drive wheel (4) is designed without flanges, and in that the driving gear (21) is provided on its two edges with respectively one guide flange (29, 30) for guiding the drive member (32).

3. A turret head as claimed in Claim 1 or 2, characterised in that the driving gear (21) can be set for tensioning the drive member (32) by means of a setting device (23, 24).

4. A turret head as claimed in one of the preceding Claims, characterised in that there is provided a deflecting wheel (31) which deflects the drive member (32) and which can be set for tensioning the drive member by means of a setting device.

5. A turret head as claimed in Claim 3 or 4, characterised in that the setting device (23, 24) comprises an eccentric.

6. A turret head as claimed in one of Claims 3 to 5, characterised in that the driving motor (18) is fastened to the housing body (25), and in that its driving shaft (19) is connected to the driving gear (21) by means of a coupling (20, 21) allowing an eccentric position of the driving gear (21).

7. A turret head as claimed in one of the preceding Claims, characterised in that the holding device is designed as a tool supporting device which serves for supporting a tool arrangement comprising a driving shank (38), and in that the drive wheel (4), which is provided with a toothed rim on its circumference, is mounted on its internal circumference and, at its end that is directed away from the tool, is provided with the clutch part (5) which can establish a nonrotatable connection to the driving shank (38) of the tool arrangement.

8. A turret head as claimed in one of the preceding Claims, characterised in that the drive wheels (4) are surrounded by the housing body (25), in which the driving gear (21) is rotatably mounted by means of the setting device (23, 24) and which carries the driving motor (18).

9. A turret head as claimed in one of the preceding Claims, characterised in that if the number of tool arrangements corresponds to half the number of index positions of the turret head, the axis of the driving gear (21 a) lies on an angle bisector (35) of an angle whose one side (33) is tangent to the driving gear and the drive wheel (4a) that is located farthest to the outside on one side in a specific index position of the turret head and whose other side (34) is tangent to the driving gear and the drive wheel (4b') that is located farthest to the outside on the other side in the index position of the turret head following the specific index position thereof.

10. A turret head as claimed in one of Claims 1 to 8, characterised in that if the number of tool arrangements corresponds to half the number of index positions of the turret head, the axes of the driving gear (21) and the deflecting wheel (31) are arranged on the perpendicular to an angle bisector (35) and at the same distance therefrom, and in that one of the sides (33) is tangent to the driving gear and the drive wheel (4a) that is located farthest to the outside on one side in a specific index position of the turret head and the other side (34) is tangent to the driving gear and the drive wheel (4b') that is located farthest to the outside on the other side in the index position of the turret head following the specific index position thereof.

11. A turret head for a machine tool substantially as hereinbefore described with reference to and as illustrated in the various figures of the accompanying drawings.