This application claims priority from German Patent Application No. 10 2012 203 842.6 filed on Mar. 12, 2012, the disclosure of which is incorporated by reference in its entirety.
The invention relates to a holder for a slip ring brush and a respective slip ring brush. Slip ring brushes are used in slip ring arrangements for transmitting electrical signals between mutually rotatable parts. At least one slip ring brush that includes an electrically conductive material will slide on a slideway made of electrically conductive material. As a result of the galvanic contact between the slideway and the slip ring brush it is possible to transfer electric current between them.
EP 0 662 736 A1 discloses a multi-fiber brush with a plurality of brush wires in which the individual brush wires are soldered into a sleeve. Several of such sleeves are integrated with (for example, by soldering) a carrier. This leads to a series of soldered electrical contact points. Such complex structural configuration is highly prone to various malfunctions.
U.S. Pat. No. 3,316,519 also discloses a multi-fiber brush, in which the individual wires are soldered into a brass body. Only one soldering point is disposed in the path of electric current. While good mechanical relief is achieved by the deep penetration of the individual brush wires into the brass body and a relatively massive soldering point, the disadvantage of this arrangement stems from its complex configuration and the relatively high complexity of the brass body. Moreover, parallel switching of several proposed brushes can be achieved only by external wiring.
EP 1 453 155 A2 discloses a slip ring brush in which the individual wires are soldered onto the surface of a printed circuit board. While simple parallel switching between and/or among the brushes is possible in this case, the disadvantageous aspect is the high level of operational susceptibility to malfunctions due to mechanically loaded soldering points. Moreover, this arrangement is not suitable for the use of multi-fiber brushes, which, in comparison with the use of individual brushes, could offer substantially better current transmission properties.
The embodiments of the present invention are directed to an assembly including a structural cooperation between a slip ring brush and a holder for slip ring brush(es), where one or more brush wires can be used in an individual brush, where simple parallel connection of several brushes is possible, and which is characterized by increased operational reliability in combination with reduced production costs.
In an embodiment, a slip ring brush includes a holding device with at least one first holding plate and a second holding plate disposed above the first holding plate. Each of the two holding plates include an attachment area with at least one clamping finger. At least one clamping finger of the first holding plate is disposed opposite a clamping finger of the second holding plate and forms a cavity for holding at least one brush wire. Preferably, several such clamping fingers are arranged in parallel and disposed opposite one another in pairs to form several cavities. A single brush wire or a plurality of brush wires (forming a multi-fiber brush, for example) is held in such a cavity. For the purpose of fixing the brush wires, a clamping sleeve encompasses at least one clamping finger of the first holding plate and the respectively oppositely disposed clamping finger of the second holding plate and at least one brush wire encompassed in the cavity formed by the clamping fingers. The clamping sleeve can be crimped on by means of a crimping tool. Alternatively, it can also be arranged in a resilient manner to compress the clamping fingers by means of its spring force.
Instead of a single brush wire or a plurality of brush wires, a prefabricated multi-fiber brush in which the ends of the brush wires are joined by a sleeve can be held by the clamping fingers. The term of multi-fiber brush shall generally be understood in this case as a multi-wire brush with several brush wires. It is alternatively referred to as a bundle brush.
In a further embodiment, the clamping fingers of the first holding plate are arranged in such a way that they can be crimped around the at least one brush wire. This embodiment may require only one holding plate and the second holding plate can be omitted because the brush wires are already held by the first holding plate alone.
The advantage of the slip ring brushes in accordance with the embodiments over the related devices is the especially simple mechanical configuration. Consequently, an embodiment of a slip ring brush is substantially based on two holding plates which can be produced as simple punched or metal-stamped parts. The mounting of the brush wires is simple and possible without any soldering. As a result, the disadvantages of soldering processing (such as deformation or a change in the spring properties of the brush wires by high soldering temperatures) are reduced or substantially prevented. The fastening of the brush wires between the clamping fingers and the fixing of the brush wires with clamping sleeves lead to a mechanically stable structure, which is operable as a permanently reliable electrical contact even under long-term loads with high vibration amplitudes. In fact, the proposed arrangement is substantially devoid of problems with mechanically loaded soldering points, in which the crystal structure of the solder changes by mechanical loading and which then subsequently breaks up. At the same time, the proposed configuration enables optional exchange and replacement of individual brush wires of a brush when they are worn out. They could be pulled out after the withdrawing the sleeve from the clamping fingers.
In the following, embodiments of the invention are described based on examples, without limitation of the general inventive concept, and with reference to the drawings.
While embodiments of the invention can be appropriately modified, several of such embodiments are shown by way of example in the drawings and described below in detail. It should be understood, however, that the drawings and detailed description are not intended to limit the invention to any particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
Clamping sleeves 36, 37, 38, 39 are provided for tightly affixing the brush wires between the clamping fingers. The position of the first holding plate 10 with respect to the second holding plate 20 can be fixed by the clamping sleeves. As shown in
Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described herein are to be taken as the presently preferred embodiments. Elements and materials may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described herein without departing from the spirit and scope of the invention as described in the following claims.
10 First holding plate
11 First attachment area
12-15 First clamping fingers
16 First fixing hole
17 Second fixing hole
20 Second holding plate
21 Second attachment area
22-25 Second clamping fingers
26 First fixing hole
27 Second fixing hole
32-35 Brush wires
36-39 Clamping sleeves
40 Cable lug
41 Connecting cable
42 Bolt
43 Nut
50 Clamping slit
51 Collar
60 Holding plate
61 Attachment area
62-65 Crimping fingers
70 Multi-fiber brush
71 Sleeve
72 Brush wires
80 Carrier
81-85 Brushes
91-95 Connecting cables
Number | Name | Date | Kind |
---|---|---|---|
2093198 | Kleinmann | Sep 1937 | A |
2716684 | Barnes | Aug 1955 | A |
3316519 | Maytone | Apr 1967 | A |
4513495 | Kimberlin | Apr 1985 | A |
4705976 | Cacioppo et al. | Nov 1987 | A |
Number | Date | Country |
---|---|---|
69414687 | Jun 1999 | DE |
0662736 | Nov 1998 | EP |
1453155 | Mar 2007 | EP |
Number | Date | Country | |
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20130237102 A1 | Sep 2013 | US |