DE9411149U1 - Manual release device for an electromagnetically ventilated spring-applied brake - Google Patents

Description

Manual release device for an electromagnetically released spring-loaded brake

The invention relates to a manual release device for an electromagnetically released spring-loaded brake with a disk-shaped armature, which can be pulled against a magnetic part by taking along the brake springs that brace a brake rotor against a fixed flange, whereby the armature is divided into a radially inner armature disk coaxial with the brake rotor and a radially outer armature disk, and through the edge area of the latter extends a release bolt arranged parallel to the axis, which can be pulled in the axial direction to the magnetic part via a hand lever, which, when the inner armature disk is released, acts on it via a release tab arranged radially on it, which passes through a recess in the outer armature disk with play.

In known electromagnetically released spring-applied brakes with such a manual release device, with which the inner armature disk can be released separately, the release tab connected to the inner armature disk can be bent by improper operation. Such manual release devices are used in particular in spring-applied brakes.

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Applications that are used in elevator operation. Here, each armature disk, which can be actuated by brake springs, represents an independent braking system, which is why in the event of a failure of one of these braking systems, the other is still functional. When servicing and checking such spring-loaded brakes, the two armature disks must therefore be able to be released independently of one another, and for this purpose the inner armature disk can be actuated separately by the release bolt via the release tab. Therefore, the release tab passes through the radial recess of the outer armature disk with considerable play, particularly in the axial direction, so that the release tab can be adjusted sufficiently far while closing the air gap for the inner armature disk without touching the outer armature disk. Therefore, when the inner armature disk sits on the magnetic part, such a high force can be exerted on the release tab via the manual release device that it causes the release tab to bend, which is not noticeable considering the force that has to be overcome by the brake springs acting on the inner armature disk. Bending the release tab of the inner armature disk can easily lead to operational problems, especially in view of the abrasion that occurs in such a spring-loaded brake. In extreme cases, the inner armature disk can then no longer be lifted off the brake rotor.

The invention is based on the object of creating a manual release device for an electromagnetically released spring-loaded brake of the generic type, in which the release tab connected to the inner armature disk is supported at the end of the release path.

This task is carried out with a manual release device from gat-&ogr;

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This object is achieved according to the invention in that a stop is provided for the release bolt, which limits the travel of the release bolt in accordance with the release stroke of the inner armature disk.

For the manual release device according to the invention, it is essential that the release bolt can only be moved towards the armature part, taking the release tab with it, as far as is necessary to relieve the load on the brake rotor, so that, in particular when the inner armature disk is in contact with the magnetic part and there is still a gap between the release tab and the outer armature disk, the release tab of the inner armature disk cannot be bent.

The stop according to the invention is expediently arranged parallel to the axis next to the release bolt and passes together with it through the edge area of the outer armature disk, whereby it is supported on the magnetic part. The stop can then be made as long in the axially parallel direction as corresponds to the nominal thickness of the inner and outer armature disk.

In a suitable embodiment, the stop according to the invention is a sleeve surrounding the release bolt, which in a particularly advantageous embodiment can be designed as a cup-shaped sleeve, accordingly having an inner flange at the end facing the magnetic part, on which a return spring for the release bolt is supported, which is consequently arranged inside this sleeve.

The invention is explained in more detail below with reference to the drawing, using an exemplary embodiment. The drawing

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2: shows a partial longitudinal section through an electromagnetically released spring-applied brake in the area of the manual release device.

In detail, the drawing shows a magnetic part 1 of the electromagnetically released spring-loaded brake, the excitation winding of which is not shown. Two coaxial armature disks 3 and 4 can be attracted to the magnetic part 1 as soon as the coil of the magnetic part 1 is electrically excited. This corresponds to the release state of the spring-loaded brake, while the drawing shows the braking case in which the armature disks 3 and 4 are moved away from the magnetic part 1 while leaving a working air gap 2. The armature disks 3 and 4 are constantly under the force of brake springs acting parallel to the axis, which are not shown in the drawing. As a result, the armature disks 3 and 4 act on a brake rotor 5, which is provided with brake pads 6 on both sides, and brace it against a fixed flange 7. As a result, the brake rotor 5, which is connected to a shaft parallel to the axis, is fixed, while in the ventilated state of the armature disks 3 and 4, it can rotate freely relative to these and relative to the fixed flange 7.

The armature disk 3, which is located further radially inwards, and the armature disk 4, which is coaxial with it and is located further radially outwards, are each acted upon by brake springs, which serves to ensure safety, particularly when used in elevator operation, by means of two independent brake spring systems.

For testing purposes, it is necessary to be able to release the two armature disks 3 and 4 mechanically by hand, i.e. not electromagnetically. A manual release is used for this purpose.

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Device 8, the essential component of which is a release bolt 9, which extends parallel to the axis and passes through the outer edge area of the outer armature disk 4. The release bolt 9 can be moved further towards the magnet housing 1 via a hand lever 10, the handle part of which is not shown, whereby it rests against either the outer armature disk 4 or a release tab 13, which extends radially inwards to the inner armature disk 3, via an adjustable or replaceable drive disk 12 supported on its head 11 on the side opposite the hand lever 10. By suitable design or arrangement, if necessary with the omission of the drive plate 12, the release bolt 9 can also act only on either the inner armature plate 3 via the release tab 13 or the outer armature plate 4, depending on whether the entire braking system or only that of the inner armature plate 3 or that of the outer armature plate 4 is to be checked.

In particular, when checking the brake system associated with the inner armature disk 3, there is the problem that the release tab 13 can be bent by the force applied via the release bolt 9 in the direction of the magnetic part 1. This is because the release tab 13 is guided from the inner armature disk 3 with sufficient play in the axially parallel direction through a recess 14 radially outwards to the release bolt 9, and therefore when only the inner armature disk 3 is ventilated after closing the air gap 2 there towards the magnetic part 1, the release tab 13 cannot be supported on the outer armature disk 4. In order to prevent the tab 13 from becoming bent in this ventilation case, the ventilation path of the release bolt 9 to the magnetic part 1 is limited by a stop 15 in the form of a sleeve. The sleeve

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15 is arranged coaxially to the release bolt 9 and passes together with it through the outer area of the outer armature disk 4. In particular, the stop 15 consists of a pot-shaped sleeve, which consequently has an inner flange 16 at its end facing the magnetic part 1, and with this end the sleeve-shaped stop 15 is supported on the magnetic part 1. The length of the stop 15 corresponds to the thickness of the inner armature disk 3, which requires that the stop 15 protrudes through a hole 18 in the release tab 13 so that its free, annular front surface 19 facing the fixed flange 7 can serve as a stop surface for the head 11 of the release bolt 9 or a drive disk 12 of suitable diameter supported on it. Thus, in the ventilation position of the inner armature disk 3, the ventilation bolt 9 is supported by the stop 15 on the magnetic part 1, whereby a residual air gap can even remain between the inner armature disk 3 and the magnetic part 1 if only the release of the brake rotor 5 is ensured so that the inner armature disk cannot be clamped against the magnetic part 1 by the manual release device 8 via the ventilation tab 13.

The design of the stop 15 as a cup-shaped sleeve offers the further advantage of being able to accommodate a return spring 17 therein, which is supported as a compression spring on the inner flange 16 of the sleeve-shaped stop 15 on the one hand and on the head 11 or the disk 12 of the release bolt 9 on the other hand and which acts on the release bolt 9 in the direction of the fixed flange 7.

Claims (4)

&eegr;&Lgr;&Tgr;&Ggr;&Mgr;&Tgr;&Lgr;&Mgr;\&Lgr;/&Lgr;&Igr;~&Ggr;£&Zgr;&Ggr; GADDHRBAUMER STRASSE 20 HA ! EU]NI AINVVALl cz n-33602 BIELEFELD DIPL.- ING. BODO THIELKING phone: (0521) 6&Ogr;621 DIPL.- ING. OTTO ELBERTZHAGEN fax: (0521) 173725 TELEX: 932059 attorney d POSTAL ACCOUNT HANNOVER
(Bank code 25010030) 3091 93-3O2 ATTORNEY FILE: 4 6 34 date: 06.07.1994/Hü Protection claims : 1. Manual release device for an electromagnetically released spring-loaded brake with a disk-shaped armature, which can be attracted against a magnetic part by taking along the brake springs that brace a brake rotor against a fixed flange, whereby the armature is divided into a radially inner armature disk coaxial with the brake rotor and a radially outer armature disk, and through the edge area of the latter extends a release bolt arranged parallel to the axis, which can be pulled in the axial direction to the magnetic part via a hand lever, which, when the inner armature disk is released, acts on it via a release tab arranged radially on it, which passes through a recess in the outer armature disk with play, characterized, that a stop (15) is provided for the release bolt (9), which limits its travel in accordance with the release stroke of the inner armature disk (3). 2. Hand release device according to claim 1,
characterized, that the stop (15) is arranged parallel to the axis next to the release bolt (9), passes together with the latter through the edge area of the outer armature disk (4) and is supported on the magnet part (1). - 2 - 4639 3. Manual release device according to claim 2, characterized in that the stop (15) is a sleeve surrounding the release bolt (9) and passing through the release tab (13). 4. Hand release device according to claim 3, characterized in that the stop (15) is a pot-shaped sleeve with an inner flange (16) at the end facing the magnetic part (1), on which a return spring (17) for the release bolt (9) is supported.