DE20306147U1 - Disc for angle grinder has non-circular mounting opening in centre of disc to receive shaped mandrel - Google Patents

Abstract

The disc for an angle grinder has a non-circular mounting opening in its centre to receive a mandrel (1) attached to the drive. The mounting opening can have a rectangular or oval cross section to correspond to that (6) of the mandrel. The opening cross section can have two parallel edges.

Description

PATENT ATTORNEYS

Dipl.-Ing. A. Wasmeier

Dipl.-Ing. H. Graf

Authorized before 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. 12

D-93008 REGENSBURG P.O. BOX 10 08 26

D-93055 REGENSBURG GREFLINGERSTRASSE 7

your message Our sign Telephone (0941)79 20 85 80297 Munich Your Letter Our Ref. (0941)79 20 86
Fax (0941)79 5106 Sch/g21.176 E-mail: wasmeier-graf@t-online.de Your sign Date Your Ref. Date 10.04.2003 Gr/Ba

Applicant:

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

Title:

Working disc for use with a mandrel and working disc-mandrel combination

Accounts: HypoVereinsbank (bank code 750 200 73) 5 839 300

Postgiro jmVl\$nchen {Oil!Z ]Ö0.10CfS0) 893j68-|301

Place of jurisdiction Regensburg

A21176.DOC
16.04.03 16:16

Working disc for use with a mandrel and working disc-mandrel combination

The innovation relates to a working disk for use on a mandrel or clamping element, for example a cutting disk, diamond disk, and/or polishing disk according to the preamble of claim 1. Furthermore, the invention relates to a working disk-mandrel combination according to the preamble of claim 6.

Work disks, particularly those for use in dental technology, are known in a wide variety of designs, including as cutting disks, diamond disks or polishing disks. In order to be able to attach such work disks to a rotatingly driven holder, for example to a chuck of a work machine, it is necessary to first attach the respective work disk to a mandrel or clamping element, which essentially consists of a shaft that can be connected to the machine holder or the chuck of the work machine and of means for detachably attaching the work disk to one end of this shaft or to a head piece formed there. These means for detachably attaching the work disk are usually clamping nuts or clamping screws. Attaching and detaching a work disk to or from the mandrel is therefore relatively time-consuming, i.e. it usually takes about 2 minutes.

The aim of the innovation is to show a working disk that enables a simplified and quick attachment and detachment from a mandrel. To solve this problem, a working disk is designed in accordance with claim 1. A combination consisting of at least one working disk and a suitable mandrel is designed in accordance with claim 6.

A21176.DOC Y J ··· · · · ·* · · ··· *· ·

The working disk according to the innovation is particularly suitable for use with a mandrel which has a holder for a torsion-proof fastening of the working disk, which has a cross-section deviating from the circular shape and on which the working disk with its fastening opening, which also has a cross-section deviating from the circular shape, can be fastened in a form-fitting manner by sliding or placing it on.

The mandrel is preferably designed in such a way that the work disk is fixed to the mandrel by means of a locking pin which creates a pin and forms a head piece at one end of this shaft and can be inserted with its shaft into an opening in the mandrel which is coaxial with the mandrel's longitudinal axis and can be locked there, so that the work disk is received between the head piece of the pin and a contact surface of the mandrel, and at the same time sits securely against rotation on the mandrel's holder.

Further developments of the innovation are the subject of the subclaims. *

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

Figures 1 and 2 a mandrel (click mandrel) for use with the

new working disk 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;

Figure 6 a working disk according to the innovation in plan view,

Figure 7 the working disk and the mandrel in side view.

The mandrel, generally designated 1 in the figures, is used to clamp working disks, for example cutting, diamond and/or polishing disks, etc.

for their use on a work tool 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, which essentially consists of a notch 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 respective working disc can be secured to the head piece 3 between the front surface 4 there and the head 10, whereby any differences in the thickness of the

Working disks are compensated by elastic spacers. After inserting the shaft 9 into the recess 5, each leaf spring-like section engages 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.

In Figure 6, the working disk is designated with 12. This has a fastening opening 13 in the middle that is not circular in shape, with which the working disk can be placed on the holder 6, which is formed by the projection that protrudes beyond the front surface 4. The cross-sectional dimensions and cross-sectional shape of the opening 13 and the holder 6 are identical, so that after placement, the holder 6 is positively received in the opening 13.

Figure 7 shows a simplified representation of the working disk 12 attached to the mandrel 1 and sitting on the holder 6. This is clamped between the front face 4 and an additional disk or a ring 14 which consists of a rubber-elastic material and is supported against the head 10. In the simplest case, the ring 14 is, for example, an O-ring.

Instead of or in addition to the disc or the ring 14, it is also possible to provide the head 10 with permanent elasticity on its side facing the shaft 9.

by means of a corresponding coating or by providing the disk or ring 14 firmly on the pin 8 or its head 10.

Furthermore, it is also possible to provide the respective working disk 12 on at least one side in the region of the opening 13 with a ring-like, permanently elastic element or application enclosing this opening, for example with a ring or a disk made of a permanently elastic material.

A21176.DOC ····· ··· · ····· ···

Claims (13)

1. Working disk, for example a cutting, diamond or polishing disk for use on a mandrel or clamping element, the working disk having a fastening opening ( 13 ) at least in the center of the disk, through which the mandrel passes when the working disk ( 12 ) is fastened to the mandrel, characterized in that the fastening opening ( 13 ) has a cross-section deviating from the circular shape, namely for a receptacle ( 6 ) of the mandrel ( 1 ) which passes through this opening in a form-fitting manner. 2. Working disk according to claim 1, characterized in that the fastening opening ( 13 ) has a square or approximately square cross-section. 3. Working disk according to claim 1, characterized in that the fastening opening ( 13 ) has an oval cross-section. 4. Working disk according to one of the preceding claims, characterized in that the fastening opening ( 13 ) has a cross-section which is defined by two straight, parallel edge lines ( 13.1 ) and by two curved edge lines ( 13.2 ) connecting these two first edge lines to form a closed edge. 5. Working disk according to one of the preceding claims, characterized in that the disk has on at least one side a ring-like element enclosing the fastening opening ( 13 ) or a ring-like section enclosing the fastening opening ( 13 ) which is designed to be rubber-elastic. 6. Working disk-mandrel combination consisting of a working disk, for example a cutting, grinding or polishing disk, and of a mandrel ( 1 ) or clamping element, which passes through a fastening opening ( 13 ) of the working disk with a mandrel section and rests against the working disk ( 12 ) with clamping surfaces ( 4 , 13 ) on both sides, characterized in that the fastening opening ( 13 ) has a cross-section deviating from the circular shape and is passed through in a form-fitting manner by the section ( 6 ) of the mandrel. 7. Combination according to claim 6, characterized in that the mandrel has a fastening element ( 8 ) for releasably fastening and for clamping the working disk between the clamping surfaces, that the fastening element is a pin with a pin shaft ( 10 ) and a head, 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 ). 8. Combination according to claim 6 or 7, characterized in that one end of the mandrel is formed by a head piece ( 3 ). 9. Combination according to one of the preceding claims, 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 ). 10. Combination according to claim 9, 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. 11. Combination 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. 12. Combination 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. 13. Combination according to one of the preceding claims, characterized in that a rubber-elastic element, for example an auxiliary disk or a ring ( 14 ) made of a rubber-elastic material, is provided between a clamping surface and the disk.