DE7404456U - Device for switching off the brushes of electrical machines - Google Patents

Description

PATENT LAWYERS

DiETRiCH LEWINSKY

REINER PRIETSCH February 8, 1974

7792-rvVK

Le Carbone-Lorraine Oennevilliers, Rue Jean-Jauree 37-41 (France)

"Device bus switching off the brushes electrical machines "

Priority from April 26, 1973 from the French patent application EN 73 15o71

The invention relates to a device for switching off the brushes electrical machines after reaching a certain wear & bus level, Consists of a capsule housed in a blind hole in the brush, one on an insulating protrusion containing pressure piece acting spring.

Such activities are known; For example, a such a device, which is located in a blind hole in the upper part of the brush, comprise a correspondingly compressed spring, on the one hand against the insulating pressure piece and on the other hand is supported against a part that closes the opening of the blind hole and is firmly connected to the brush. Another The possibility is to submerge the spring in the capsule mentioned at the beginning, which is in the blind hole in the brush in any one attached in a suitable manner.

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Μ? The basic principles of such devices are the following:

their introduction and application is in the blind hole of the brush difficult;

as soon as the brush has reached its versehlelfigrenie and itself lifts off the collector, the insulating pressure piece occurs frequently out of the hole and is swept away by the collector, causing harmful Sees consequences.

One possible remedy is «tarin, a pressure piece from in relation on the displacement path of the peder of the holding device large; Provide length so that the pressure piece is continuously * guided in the hole

j remains «whereby, however, the device takes up a relatively large amount of space

addressed, which is often a problem. Sin «other possibility of

j The remedy is to place a school-

j ter to ensure that the pressure piece emerges completely

prevented. However, if the brush is made of soft material, this shoulder is sometimes not stable enough to Hold the pressure piece of the cut-off device securely.

When replacing the worn or used brush, there is a risk that the pressure piece and the spring will penetrate the bottom of the Blind holes fall out, unless a spring is used, the ends of which are force-locked into the capsule (if the device contains such a) and are locked into the pressure piece, which is expensive, however, since the spring has a grasping * shape and because their installation is inevitably difficult.

The invention is based on the object of creating a device of the type specified in the introduction which, with simple Structure reliably prevents the pressure piece from sliding out of the brush when it is worn.

This object is achieved according to the invention in that the capsule

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the isolating «printing block tsil ^ siss issue * md ss d * ^ at least one of their lower part, which fits tightly in the brush, the displacement path of the Druckstüokes limiting and the complete Step out of the pressure piece under the pruek of the spring when stopping the brush and / or when lifting the switched off brush has a preventing constriction.

The protruding fingers of the isolating pressure vacuum also play a role here the constriction or constrictions of the capsule so that the displacement of the pressure piece in the capsule and thus in the worn brush is limited to the desired value.

The shape of the constriction or constrictions depends on the heel used * *! Dpuekatflakes off.

In the drawing, the device according to the invention is based on of exemplary selected embodiments shown schematically. Show it:

Figure 1 a Schmitt through a brush with a first Embodiment of the device,

FIG. 2 shows a representation corresponding to FIG. 1, however

after reaching the predetermined wear condition the brush,

Figure 3 is a perspective view of a further embodiment the device,

characters

4-7 two advantageous developments of the device,

in each case in the installed state and in the one resulting after reaching the wear limits of the brush Working condition.

FIG. 1 shows a section through a brush 1 which is pressed against a collector 2 by a spring 3. The brush is with a shutdown device provided in a blind hole 4 of the

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Brush is housed and encompasses a capsule 5, in which see an · on «in insulating öruakstüek 7 acting · spring 6 b«

The insulating Druekstttek 7 is formed so that the diameter its lower end is smaller than that of its upper part.

According to the invention, the capsule 5 has a constriction 8 which from an annular indentation (as shown) or from There is a claw-shaped design (not shown).

As soon as the bristle has reached its Versehleiftgrense, it is switched off (Figure 2) and the constriction 8 of the capsule limits the displacement of the insulating Druekstüekes 7 by holding its upper, alnkmrmn Til

FIG. 3 shows a perspective illustration and other things Scale an embodiment in which the insulating printing block 7 has grooves 9a, 9b, 9c in its dumbbell surface, which are only open near the bottom. The constriction of the capsule 5 consequently consists of Claw-shaped indentations 10a, 10b, 10c, which correspond to the grooves of the printing piece, so that the latter is only a limited displacement of the pressure piece when the brush is switched off.

As can be seen from these two examples, the constriction of the capsule, which is always shaped, holds the insulating pressure block effectively once the brush has reached its gravity. There is therefore no risk of the printing block from The collector is swept away as soon as the brush takes off.

In addition, according to the invention, a spring of simple shape can be used without frictional locking of their ends into the capsule and into the ! insulating printing block must be used, as when replacing the ! There is no danger of brushing the insulating pressure block and

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the spring will fall out through the bottom of the hole.

~ Ü3T basic idea άζτ invention can be used from d * a to her-

\ position of the capsule material used can be realized.

j If the capsule is made of brass, for example, the

narrowing by embossing after inserting the spring and the pressure

j piece can be generated.

\ The inventive idea is also both one-piece capsules, as well as those applicable, which are composed of several, optionally perforated parts.

According to an advantageous further development, the capsule can also have shoulders in its interior that are certain to penetrate Prevent the pressure piece during assembly, so that the lower end of the pressure piece always protrudes above the bottom of the capsule. This shoulder prevents the capsule from coming to rest on the collector when the brush reaches its end Has.

This development is shown in FIGS. 4, 5, 6 and 7, which, however, only illustrate possible exemplary embodiments.

The figures show in section a capsule 5 with a narrowed 'η Part 8 in the form of a collection and also with an inner shoulder? * 11, which the lower end of the pressure piece 7 always over leaves the bottom of the capsule sticking out.

Figures 4 and 5 illustrate an embodiment at which the shoulder is formed in a cylindrical capsule. Figures 6 and 7 illustrate another embodiment, in which the shoulder is formed by an indentation in the upper part of the capsule. Figures 4 and 6 illustrate the Position of the pressure piece during assembly * Figures 5 and 7

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illustrate the position of the pressure piece as soon as the brush has reached its wear limit and is switched off.

Finally, there is a particularly salient advantage to be pointed out in the invention. This consists in the fact that a unit consisting of the spring, the pressure piece and the capsule is prefabricated which can be easier insertion into the pocket of the brush, a considerable saving of time and possibly the Automation of the process of inserting or fastening allows.

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Claims (3)

1 * Provision of sun switching off the brushes of electrical machines after reaching a certain state of damage, consisting of a capsule accommodated in a blind hole in the brush, which contains a spring acting on an insulating, protruding pressure block, characterized in that the capsule (5) is the insulating Part of the pressure piece (7)? 6) has a constriction (8) preventing the brush (1) from being held off and / or when the switched-off brush is lifted off. 2. Vorriehtung naeh claim 1, characterized in that the constriction (8) consists in an annular recess. 3. Device according to claim 1, characterized in that the constriction consists of claw-shaped impressions (loa, lob, loe). J ». Device according to one of claims 1 to 3 »characterized in that daft the capsule (5) inside a penetration of the pressure piece (7) during assembly on such The shoulder (11) which limits the value, so that the end of the pressure piece (7) always protrudes beyond the diameter of the capsule. 7404456 08/07/75