Abstract:
Devices for supplying fuel are already known, having a supply unit which has a pump housing connected to an electrical ground and is supported on a pump mount. It is disadvantageous that during operation, the pump mount can become electrostatically charged and has no device for electrostatic discharging during operation. 
     The invention provides an especially simple and economical grounding device for the pump mount. In particular, a charge diverter is connected to the pump housing via a grounding element, and contacts a surface of the pump mount.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a 35 USC 371 application of PCT/EP 2007/061053 filed on Oct. 17, 2007. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention is based on a device for supplying fuel. 
     2. Description of the Prior Art 
     A device for supplying fuel is already known, having a supply unit which has a pump housing connected to an electrical ground and is supported on a pump mount. It is disadvantageous that during operation, the pump mount can become electrostatically charged and has no device for electrostatic discharging during operation. 
     ADVANTAGES AND SUMMARY OF THE INVENTION 
     The device according to the invention has the advantage over the prior art that an electrostatic discharge of the pump mount takes place during operation, in that a charge diverter rests on a surface of the pump mount and is connected to the pump housing via a grounding element. 
     It is especially advantageous that the charge diverter is made from brass, copper or steel, since these materials are electrically conductive and thus divert the electrostatic charges. 
     It is also advantageous if the grounding element is attached to the pump mount by at least two retaining arms and with at least one first spring arm contacts the charge diverter and with at least one second spring arm contacts the pump housing. This embodiment is especially economical to make from a sheet-metal strip and is especially easy to assemble by machine. Grounding the pump mount does not require any expensive and complicated welded or soldered connections. 
     In an advantageous embodiment, the retaining arms of the grounding element are angled relative to the center rib, in order with the retaining arms to form an insertable clamp. The spring arms are likewise angled relative to the center rib, so that they can press resiliently against the respective contact partner. 
     It is highly advantageous if the spring arms are rounded on their ends toward the contact, since in this way a good electrical contact is obtained. 
     It is also advantageous if the retaining arms are embodied with sharp edges on their ends remote from the center rib, since in this way an especially firm clamp action of the grounding element on the pump mount is obtained, so that the grounding element is especially well fixed and cannot come loose or be shifted by vibration. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One exemplary embodiment of the invention is described in further detail in the ensuing description in conjunction with the drawings, in which: 
         FIG. 1  shows a three-dimensional view of the device for supplying fuel; and 
         FIG. 2  shows a grounding element according to the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a three-dimensional view of the device for supplying fuel in simplified form. 
     The device is disposed in a reservoir  1 , such as a fuel tank and has a supply unit  2 , which supplies fuel from the reservoir  1  to an internal combustion engine  3 . 
     The supply unit is an arbitrary pump, such as a flow pump or a positive displacement pump. 
     The supply unit  2  has a cylindrical metal pump housing  2 . 1 , which is electrically conductively connected to an electrical ground  6  and in this way is grounded. The electrical ground  6  is for instance the body of the vehicle. The pump housing  2 . 1  is closed at its face end by a connection cap  2 . 2 , on which in this instance two connection plugs  5  are provided for making contact with a voltage source  7 . 
     The supply unit  2  is supported on a pump mount  10 , which is secured to the reservoir  1  or, in the exemplary embodiment, to a storage container  11  on the reservoir  1 . The storage container  11  keeps enough fuel on hand that even if the fuel sloshes back and forth in the reservoir  1 , fuel can still be aspirated and supplied. The storage container  11  is provided on a bottom  12  of the reservoir  1 . 
     The pump mount  10  damps vibration originating at the supply unit  2 , so that as little structure-borne sound as possible is transmitted to the reservoir  1 . In the exemplary embodiment, this is attained by means of two retaining rings  14 ,  15 , disposed concentrically to one another, which are mechanically connected to one another by means of elastic elements  16 . The supply unit  2  is secured to the inner retaining ring  14 , and the outer retaining ring  15  is for instance secured to the storage container  11 . The elastic elements  16  are connected for instance integrally to the two retaining rings  14 ,  15  and extend over a predetermined length in the circumferential direction relative to the retaining rings  14 ,  15 . The pump mount  10  is made from plastic, for instance. 
     The electrostatic charges that accumulate at the pump mount  10  have to be diverted, for the sake of fire prevention. 
     According to the invention, it is therefore provided that a charge diverter  17 , which is connected to the pump housing  2 . 1  via a grounding element  18 , contacts a surface of the pump mount  10 . 
     The charge diverter  17  in the exemplary embodiment is embodied annularly and surrounds the inner retaining ring  14 . However, it can expressly have any other shape as well. For instance, the charge diverter  17  is press-fitted onto the inner retaining ring  14  and prevents swelling of the inner retaining ring  14 . The charge diverter  17  is made from metal, such as brass, copper, or steel. 
     According to the invention, the grounding element  18  is slipped onto the pump mount  10 , for instance onto the outer retaining ring  15 . For that purpose, the grounding element  18  has at least two resilient retaining arms  19 , which project over or clamp the outer retaining ring  15  and retain the grounding element  18  on the pump mount  10  with a predetermined spring force. For instance, three retaining arms  19 , disposed side by side and spaced apart from one another, are provided, and the two outer retaining arms  19  contact the outer circumference, and the middle retaining arm  19  contacts the inner circumference, of the outer retaining ring  15 . The retaining arms  19  are angled such that the retaining arm  19  provided on the inner circumference is spaced apart from the other retaining arms  19  by approximately the thickness of the outer retaining ring  15 . 
     The grounding element  18  has at least one first spring arm  21  and at least one second spring  22  arm; the first spring arm  21  contacts the charge diverter  17 , and the second spring arm  22  contacts the pump housing  2 . 1 . For instance, two first spring arms  21  and one second spring arm  22  are provided, and the one second spring aim  22  is disposed between the two first spring arms  21 . The three spring arms  21 ,  22  are spaced apart from one another. The spring arms  21 ,  22  press with a predetermined spring force against their contact partner of the pump housing  2 . 1 , and the charge diverter  17 . 
     The retaining aims  19  and the spring arms  21 ,  22  are joined together via a center rib  23 . The spring arms  21 ,  22  are disposed on one long side, and the retaining arms  19  on the opposite long side, of the center rib  23  and extend transversely to its length. 
     The inner retaining ring  14  has in this instance one cutout  14 . 1 , through which the second spring arm  22  contacts the pump housing  2 . 1 . 
       FIG. 2  shows a grounding element according to the invention as in the device of  FIG. 1 . 
     In the grounding element of  FIG. 2 , those parts that remain the same or function the same as in the device of  FIG. 1  are identified by the same reference numerals. 
     The grounding element  18  of the invention is made from a sheet-metal strip, for instance of spring steel. The retaining arms  19  and the spring arms  21 ,  22  are angled by approximately 90°, for instance, relative to the center rib  23 , so that the retaining arms  19 , center rib  23  and spring arms  21 ,  22  form a step shape. The spring arms  21 ,  22  are angled one more time on their ends toward the contact partner of the pump housing  2 . 1 , and the charge diverter  17  for the sake of making contact and are rounded directly at the contact point, for instance by means of a bending radius R. 
     The retaining arms  19  are embodied with sharp edges on their ends remote from the center rib  23 , so that the grounding element  18  is connected especially solidly to the pump mount  10 . For instance, the retaining arms  19  are bent over with sharp edges on those ends. 
     The foregoing relates to the preferred exemplary embodiment of the invention, it being understood that other variants and embodiments thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims.