Abstract:
A brush holder which has a holder housing and at least one fastening lug projecting laterally from the holder housing. The fastening lug is provided with an upwardly directed bent portion and a return part extending as far as the outside of the holder housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. national stage application of International Application No. PCT/EP2006/067565 filed Oct. 19, 2006, which designates the United States of America, and claims priority to German application number 10 2005 053 020.6 filed Nov. 7, 2005, the contents of which are hereby incorporated by reference in their entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a brush holder. 
       BACKGROUND 
       [0003]    The practice of placing the carbon brushes which are used in a commutator motor for contacting the rotating commutator in a brush holder is already known. In these holders the brushes are connected to a spring which pushes the brush towards the commutator in each case. During assembly a retaining device makes sure that the respective carbon brush remains in an assembly position in which it is at a desired distance from the commutator. At the end of assembly the retaining device is released, so that the carbon brush is pushed by the force of the spring towards the commutator and contacts the latter. The brush holders are attached to a brush carrier. This attachment is undertaken for example using an ultrasound welding process or by means of hot stacking. 
         [0004]    An example of a brush holder from the applicant, which is attached to a brush plate, is shown in  FIG. 1 . 
         [0005]    The brush holder  2  shown in this figure features fastening lugs  7  and  8 , which are provided with a punched out section  7   c ,  8   c  in each case. Melted material  3 ,  4  is introduced into this punched out section during ultrasound welding or during hot stacking which, after cooling off, takes care of the desired attachment of the brush  2  on the brush plate  1 . 
         [0006]    The brush holder  2  shown in  FIG. 1  features a holder housing  2   a  with a rear wall  2   b , against the inside of which a spring  5  is supported. The other end of the spring  5  presses onto a carbon brush  6  likewise located within the brush holder housing  2   a , which in the operating state projects slightly from the front side of the brush holder housing and is in contact with the commutator  11  there. The upper side of the brush holder housing  2   a  is provided with a contacting opening  10 , through which the electrical contacting of the carbon brush  6  positioned within the brush holder housing takes place. 
         [0007]    The brush holder  2  involves a one-piece stamped and bent part made of sheet brass, steel or copper which has been manufactured by automatic stamping and bending machines. 
         [0008]      FIG. 2  shows a sketch of a cross-sectional view of the device shown in  FIG. 1  along the cut line A-A′ shown in  FIG. 1 , with the carbon brush placed within the brush holder housing not being shown in  FIG. 2 . It can be seen from  FIG. 2  that one of the ways in which the brush holder  2  is attached to the brush plate  1  is that, after an ultrasound welding process or a hot stacking has been undertaken, solidified melted material  3  is fed through the punched-out part  7   c  in the attachment lug  7  and emerges outwards above the punched-out part, i.e. to the left and right in the figure. 
         [0009]    The contacting opening  10  provided on the upper side of the brush holder housing  2   a  can also be seen from  FIG. 2 .  FIG. 2  also reveals that the brush holder housing  2   a  is provided with a slit  9  in the vicinity of the solidified melted material  3  which is produced during the stamping and bending process. 
         [0010]    It has been shown that with hot stacking or ultrasound welding process melted material can penetrate in an undesired manner through this slit  9  into the interior of the brush holder housing  2   a , solidifies there and during subsequent operation hinders movement of the carbon brush within the brush housing. 
       SUMMARY 
       [0011]    According to an embodiment, a brush holder, may comprise a brush holder housing and at least one attachment lug projecting sideways from the brush holder housing, wherein the attachment lug has an upwards bend and a return part extending up to the outer side of the brush holder housing. 
         [0012]    According to a further embodiment, the brush holder may comprise two attachment lugs projecting sideways from the brush holder housing, each of which has an upwards bend and a return part extending to the outer side of the brush holder housing. According to a further embodiment, the attachment lugs each may comprise two congruent punched-out sections located above one another. According to a further embodiment, the brush holder can be made of sheet brass, steel or copper. According to a further embodiment, the brush holder can be a one-piece component. According to a further embodiment, the brush holder may be manufactured by a stamping and bending machine. According to a further embodiment, in the area in which the attachment lugs come out of the brush holder housing the attachment lugs may comprise a slit in each case, which is covered by the return part of the respective attachment lug on the outer side of the brush holder housing. 
         [0013]    According to yet another embodiment, a method for manufacturing a brush holder, with a brush holder housing and at least one attachment lug projecting sideways from the brush holder housing, by means of a stamping and bending process, may comprise: in the stamping and bending process the attachment lug is bent upwards and returned to the outer side of the brush holder housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    Further advantageous characteristics of the invention emerge from the subsequent explanation of the invention which refers to  FIGS. 3 and 4 . The figures show 
           [0015]      FIG. 1  shows an example of a brush holder which is attached to a brush plate. 
           [0016]      FIG. 2  shows a sketch of a cross-sectional view of the device shown in  FIG. 1 . 
           [0017]      FIG. 3  a cross-sectional view of a device which features a brush holder according to an embodiment, and 
           [0018]      FIG. 4  a perspective diagram of an brush holder according to an embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    The advantages of the invention lie especially in the fact that melted material produced during a hot stacking or ultrasound welding process is not able to get into the inside of the brush holder housing and solidify there. As a result the movement of the carbon brushes in the brush holder housing is not impeded during operation by solidified melted material. This advantage is attributable to the fact that inventively the attachment lugs of the brush holder are provided with a bend section in case and feature a return part which extends to the outer side of the brush holder housing  2   a  and covers the slit  9  of the brush holder housing resulting from the manufacturing process. This means that it is not possible for escaping melted material to get into the slit  9 . 
         [0020]      FIG. 3  shows a cross-sectional view of a device which features a brush holder  2  according to an embodiment. This brush holder  2  is attached to a brush plate  1 . This attachment has been produced by using a hot stacking or an ultrasound welding process to direct melted material  3  through congruent punched-out sections  7   c  a of an attachment lug  7  lying above one another and then letting the material solidify. 
         [0021]    The attachment lug  7  is embodied longer than the one for the brush holder shown in  FIG. 2  and features a bend  7   a  and a return part  7   b  which extends to the outer side of the brush holder housing  2   a . This means that the slit  9  is not accessible for melted material which is produced during of the hot stacking or ultrasound welding process. The result is that the possibility of melted material getting into the inside of the brush holder housing  2   a  through the slit  9 , solidifying there and being able to impede the movement of the carbon brush in the brush holder housing during operation is excluded. 
         [0022]    The brush holder according to an embodiment shown in  FIG. 3  is a one-piece component manufactured by a stamping and bending machine from sheet brass, steel or copper. According to various embodiments, manufacturing involves the stamping and bending machines folding over the attachment lug  7 ,  8  and bringing the folded-over part back as a return part  7   b ,  8   b  up to the outer side of the brush holder housing  2   a , so that the slit  9  in the brush holder housing resulting from the manufacturing process is closed off. 
         [0023]      FIG. 4  shows a perspective diagram of a brush holder according to an embodiment. It can be seen from this diagram that the brush holder  2  is provided with a brush holder housing  2   a  featuring a rear wall  2   b , an attachment lug  7 , an attachment lug  8  and on its upper side with a contacting opening  10 . The front side of the brush holder housing  2   a    3  is embodied open, so that in later operation a carbon brush placed within the brush holder housing can project forwards from the brush holder housing in order to contact the commutator. 
         [0024]      FIG. 4  further reveals that the attachment lug  7  also features an upwards bend  7   a  and a return part  7   b  extending back to the outer side of the brush holder housing  2   a . The attachment lug  7  is also provided with congruent punched out sections  7   c  located above one another, through which during attachment of the brush holder to a brush plate, i.e. during hot stacking or ultrasound welding, melted material can be introduced which then solidifies and brings about the desired attachment. 
         [0025]    The attachment lug  8  provided on the other longitudinal side of the brush holder housing  2   a  has an upwards bend  8   a  and a return part  8   b  extending up to the outer side of the brush holder housing  2   a . Furthermore the attachment lug  8  is equipped with congruent punched out sections  8   c  located above one another, through which during attachment of the brush holder to a brush plate, i.e. during hot stacking or ultrasound welding, melted material can be introduced which then solidifies and brings about the desired attachment. 
         [0026]    The advantages of the invention not only lie in the fact that no melted material can get into the inside of the brush holder during hot stacking or ultrasound welding, but also in the fact that the attachment of the brush holder to the brush plate is improved, since on account of the increase in height caused by the bending and return of the attachment lug, more melted material contributes to the attachment for each attachment lug.