DE20303657U1 - Mandrel for machine tool including parting off and polishing tools has enlarged base at one end of shaft with blind bore to accommodate pin on mounting system - Google Patents

Abstract

The mandrel (1) has an elongated parallel-sided shaft (2) made in one piece with an enlarged base (3). There is a conical transition between the shaft and the base. There is a flange (4) at the end of the base and an non-rotating fastening (6). Leaf springs (7) extend into the blind bore (5) in the base. The fastening system for the mandrel includes a pin which extends into the blind bore.

Description

·

PATENT ATTORNEYS'

Dipl.-Ing, A. Wasmeier Dipl.-Ing. H. Graf

'Admitted to the European Patent Office + Trade Mark Office · Professional Representatives before the European Patent Office + Trade Mark Office

Patent Attorneys PO Box 10 08 26 93008 Regensburg

German Patent and Trademark Office Zweibrückenstr.

80297 Munich D-93008 REGENSBURG P.O. BOX 10 08

D-93055 REGENSBURG GREFLINGERSTRASSE

phone

(0941)79 20 (0941)79 20 (0941)79 5106

Fax E-mail: wasmeier-graf@t-online.de

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Your Message Your Letter Our Sign
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Sch/g 21,071

date

04.03.2003 Gr/Ba

Applicant:

DFS Dental Research Schleicher GmbH Haidhof Industrial Estate Ländenstraße 1
93339 Riedenburg

Title:

Mandrel for working discs

Accounts: HypoVereinsbank (bank code 750 200 73) 5 839

Postgiroamt Mjmehejr»(BLZ 700100"8Q)OiKJ 69.-8S1 Place of jurisdiction Regensburg

.121071 DOC Jo 04 03 12

Mandrel for working discs

The innovation relates to a mandrel or clamping element for working discs, i.e. in particular for cutting discs, diamond discs and/or polishing discs according to the generic term of protection claim 1.

In order to be able to attach work disks to a rotatingly driven holder, for example to a chuck of a work machine, it is necessary to provide the respective work disk on a mandrel or clamping element, which essentially consists of a shaft that can be connected to the holder or chuck of the work machine, with means for releasably attaching the work disk to one end of the shaft or to a head piece formed there. These means for releasably attaching the work disk are usually formed by a clamping nut. Attaching and detaching a work disk to or from a conventional mandrel is therefore relatively time-consuming (usually around two minutes).

The aim of the innovation is to show a mandrel with which a working disk can be attached and detached in a simplified and quick manner. To solve this problem, a mandrel is designed in accordance with claim 1.

The innovation is explained in more detail below using the figures of an example. They show:

Figures 1 and 2 the new mandrel (click mandrel) in side view

and in front view;
Figures 3-5 a click pin of the mandrel of Figures 1 and 2 in two

different side views as well as in a view from the

lower pin end.

The mandrel, generally designated 1 in the figures, serves to clamp working disks, for example cutting, diamond and/or polishing disks, etc. for their use on a work device not shown, for example on a motor-driven chuck not shown.

The mandrel 1 is made in one piece, e.g. from metal or another suitable material, with a shaft 2 and a head piece 3, which is provided at one end of the shaft and, like the shaft 2, is rotationally symmetrical to a mandrel longitudinal axis L. The shaft 2 and the head piece 3 are arranged on the same axis as one another.

In the head piece 3, an opening 5 is provided on the front side 4 facing away from the shaft 2 and is aligned with the longitudinal axis L. Furthermore, a receptacle 6 is formed there, which surrounds the edge of the opening 5 for the torsion-proof fastening of the respective working disk. The receptacle 6 is formed by a projection which has an outside diameter that deviates from the circular shape and is adapted to the opening of a working disk.

Two leaf spring-like spring sections 7 are formed on the head piece 3 and are made in one piece with this head piece, for example by slitting or lasering from the material of the head piece 3. These spring sections 7, which extend in the direction of the longitudinal axis L, are connected to the rest of the head piece 3 at their end adjacent to the front face 4 and protrude into the recess or opening 5 with their other spring section end 7.1, which is located away from the front face 4.

A click pin 8 is used to fix the respective cutting disc to the head piece 3. This essentially consists of a shaft 9 with a head 10. At the end remote from the head, the shaft 9 is provided with two recesses 11, which, like the two leaf spring sections 7, are offset by 180° around the longitudinal axis L. By inserting the shaft 9 into the opening 5, the

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The respective working disk is secured to the head piece 3 between the front surface 4 there and the head 10, with any differences in the thickness of the working disks being compensated for by elastic spacers. After the shaft 9 has been inserted into the recess 5, each leaf spring-like section snaps into place with its end 7.1 in a recess 11, so that the click pin 8 is secured in the mandrel 1.

By turning the click pin 8 by 90°, it can be unlocked and the respective working disk can be removed from the click mandrel 1. During this rotation, the end 7.1 of each spring section 7 slides, moving radially outward, from the recess 11 onto the part of the shaft 9 that does not have this recess, so that the latter can then be pulled out of the opening 5.

The clamping and removal of the respective working disk on or from the mandrel 1 is possible in a few seconds, whereas previously this clamping was relatively time-consuming.

Claims (6)

1. Mandrel or clamping element for working disks, for example for cutting, grinding and/or polishing disks, with a shaft ( 2 ) for fastening the mandrel to a holder or clamping device of a working machine and with a fastening element ( 8 ) for releasably fastening and for clamping the working disk between a clamping surface ( 4 ) formed on one end of the mandrel and the fastening element ( 8 ), characterized in that
that the detachable fastening element is a pin ( 8 ) with a pin shaft ( 10 ) and a head ( 10 ),
that at one end ( 3 ) of the mandrel there is an opening ( 5 ) for the pin shaft ( 9 ) which is coaxial with the mandrel longitudinal axis (L), and that locking means ( 7 , 11 ) are provided in order to anchor the pin ( 8 ) or its shaft ( 9 ) by releasably locking locking means in the opening ( 5 ). 2. Mandrel according to claim 1, characterized in that one end of the mandrel is formed by a head piece ( 3 ). 3. Mandrel according to claim 1 or 2, characterized in that the locking means are formed by at least one resilient locking element ( 7 ) formed from the material of the mandrel or the head piece ( 3 ) and by at least one recess ( 11 ) on the pin shaft ( 9 ). 4. Mandrel according to claim 3, characterized in that at least two resilient locking elements ( 7 ) are provided offset about the mandrel axis (L), and that each locking element is assigned a recess ( 11 ) on the pin shaft ( 9 ) forming a counter-lock. 5. Mandrel according to one of the preceding claims, characterized in that on the circumference of the pin shaft ( 9 ) in the circumferential direction, the at least one recess ( 11 ) and at least one circumferential region of the shaft ( 9 ) alternate at which the shaft does not have the recess forming the counter-lock. 6. Mandrel according to one of the preceding claims, characterized in that the mandrel ( 2 ) or the mandrel head piece ( 3 ) has a receptacle ( 6 ) on the front or clamping surface ( 4 ) for the working disk for a torsion-proof fastening of this working disk.