Abstract:
A grounding contact for grounding a structure made of metal is provided. The grounding contact comprises a grounding attachment part having a grounding contact surface for placement on the structure. A pin attaches the grounding attachment part to the structure. The grounding contact includes a contact surface for contacting a ground wire. The grounding attachment part also includes a blind hole that accepts the pin to help ensure that corrosion is permanently avoided between the bearing contact surface of the grounding attachment part and the structure.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims priority to German Patent Application DE 10 2010 043 509.0, filed Nov. 5, 2010, and entitled “Erdungskontakt” (“Grounding Contact”), the entire content of which is incorporated herein by reference. 
       FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    [Not Applicable] 
       MICROFICHE/COPYRIGHT REFERENCE 
       [0003]    [Not Applicable] 
       BACKGROUND OF THE INVENTION 
       [0004]    The present invention relates to a grounding contact for grounding a structure made of metal, a method for attaching a grounding contact on a structure, and a structure including a grounding contact. 
         [0005]    For structures made of metal, especially steel, it is similar to that with machines meaning the structure needs to be grounded, in order that the structure, when subjected to electrical current or lightning strikes, protects people or property from the lethal health hazard or deadly current. For this purpose, the structures are provided with a grounding point at which one grounding contact is attached. The grounding contact is connected to a ground wire, which is grounded, so that due to the electrically conductive connection between the ground wire, the grounding contact and the structure, the structure is grounded. 
         [0006]    For structures made of steel, which are generally provided with an organic protective coating, the protective coating must be removed extensively first before a steel plate is soldered on. Subsequently, a large stud is soldered onto this steel plate in a complicated way. A grounding contact can be attached to the threaded bolt. Thus, the electrical connection to the grounding is assured, because a ground wire is attached to the grounding contact and is mechanically and electrically contacted. Subsequently, these parts are provided with a corrosion protection, for example a protective coating. This is a costly and labor-intensive and thus expensive approach to grounding a structure. 
         [0007]    From U.S. Pat. No. 6,991,478 B2 a grounding contact for the grounding of an aircraft is known. The grounding contact has a grounding attachment part. The grounding attachment part is provided with a through hole and a seal. Due to the through hole on the grounding attachment part liquid can enter the contact surface between the grounding attachment part and the aircraft, so that there is the risk of corrosion between the grounding attachment part and the grounding contact surface on the aircraft. 
       BRIEF SUMMARY OF THE INVENTION 
       [0008]    An object of embodiments of the present invention is to provide a grounding contact, a method for attaching a grounding contact to a structure, and a structure including a grounding contact, where corrosion between the grounding contact surface of a grounding attachment part and the structure can be permanently avoided. 
         [0009]    This problem may be addressed with a grounding contact for grounding a structure comprising a grounding attachment part with a grounding contact surface for resting on the structure, a receptacle for a fastening element, such as a cartridge-fired pin, for fixing the grounding attachment part to the structure, and a contact surface for contacting a ground wire, whereby the grounding attachment part has a blind hole and the cartridge-fired pins may be fastened in the blind hole of the grounding attachment part. After fixing, the cartridge-fired pin is preferably set in the blind hole of the grounding attachment part. No fluid, such as a liquid or a gas with water vapor, can enter through the grounding attachment part to the grounding contact surface and/or into the blind hole. In this manner, a permanent corrosion protection between the grounding contact surface and the structure or component of the structure is ensured. 
         [0010]    In particular embodiments, the grounding attachment part may be formed as a single piece. 
         [0011]    In another embodiment, the grounding attachment part is provided with a seal on the grounding contact surface, for example a seal ring. The seal ensures a particularly good seal between the grounding contact surface and the structure or component of the structure. The seal preferably completely surrounds the ground contact surface or a portion of the ground contact surface so that thereby no moisture or liquid can penetrate on the surface area between the grounding contact surface of the grounding attachment part and the surface of the structure or component of the structure, on which the grounding contact surface rests due to the seal&#39;s seal. Thus, this keeps the area between the grounding contact surface and the structure protected from moisture or liquid, especially water, and permanent corrosion protection of the contact area between the grounding contact surface and the structure or component of the structure is ensured. 
         [0012]    In an additional embodiment the seal is fixed to a groove, in particular, an annular groove disposed on the grounding contact surface. 
         [0013]    Preferably, the cartridge-fired pin has an interlocking and/or friction-locked and/or firmly bonded compound fixed in the blind part of the grounding attachment part. The cartridge-fired pin can be fixed in the blind hole or the grounding attachment part, for example, with a bayonet mount, a locking connection, or a firmly bonded connection such as a soldered connection. 
         [0014]    In one variant, the cartridge-fired pin is provided with a male thread and the grounding attachment part is provided with a female thread in the blind hole and, by means of the male and female thread, the cartridge-fired pin is connected to the grounding attachment part. With a threaded connection between the cartridge-fired pin and the grounding attachment part, following the fixing of the cartridge-fired pin to the structure or the component, simply by bolting down the grounding attachment part using a compressive force applied to the structure or component, a large compressive force exists between the grounding contact surface of the grounding attachment part for a permanent contact and/or a fluid-tight seal between the grounding attachment part and the structure or component. 
         [0015]    It is suitable that the grounding attachment is formed as a solid material without a cavity and/or that the blind hole displays the only fluid-conducting connection on the grounding attachment. The grounding attachment part has no additional fluid-conducting connection, such as a channel or opening of the blind hole in the area other than that of the blind hole opening, so that the grounding contact surface on the structure is thus completely sealed, because due to the grounding attachment part, no fluid, such as water, can enter the grounding contact surface and/or the blind hole. 
         [0016]    In another embodiment the grounding attachment part consists at least partially, in particular, completely of metal, for example, steel, stainless steel, copper or aluminum. 
         [0017]    Embodiments of the present invention relate to a process for attaching a grounding contact with a grounding attachment part and a grounding contact surface to a structure made of metal or a component of a structure, such as a wall or a ceiling or a beam of a structure made of metal, comprising the steps: Attaching a cartridge-fired pin to the structure or component, placing and contacting of the grounding attachment part to the grounding contact surface on the structure or component, fixing the pin to the grounding attachment part whereby the grounding contact surface is sealed by a seal, in particular a sealing ring, and/or the grounding contact is constructed as described in this property right application. 
         [0018]    In particular embodiments, the grounding contact area is sealed from the seal so that no fluid can be introduced between the grounding contact surface and the structure or component at the grounding contact surface and/or the seal is arranged between the grounding attachment part and the structure or component. 
         [0019]    In a further embodiment, the seal, when loading the grounding attachment part to the structure or component, is elastically tensioned. Due to the elastic tension of the seal between the grounding attachment part and the structure, a sufficient sealing can be ensured for deformations, in particular, temperature-induced deformations of the grounding attachment part and/or the pin and/or the structure, because even with such deformations or strains, with an elastically tensioned seal, a reliable seal between the grounding attachment part and the structure or component can still be ensured. 
         [0020]    In a supplemental embodiment a ground wire is mechanically and electrically contacted with the grounding attachment part. 
         [0021]    In another embodiment, coatings, in particular electrically poor- or non-conductive coatings, for example, as a protective coating or a hot galvanization of the structure or component, are removed before the placement of the grounding contact surface of the grounding attachment part onto those areas on which the grounding contact surface is placed on the structure of the components. Such coatings should be removed prior to the placement of the grounding contact surface onto the structure or component so that a sufficient current-carrying connection exists between the structure or the component and the grounding attachment part. 
         [0022]    In a further embodiment, the pin is attached in a through hole or blind hole of the structure or component by means of soldering, screwing, or pressing. 
         [0023]    A structure or component according to aspects of the present invention, for example, a wall or ceiling, or a beam, includes a grounding contact attached to the structure or components with a grounding attachment part with a grounding contact surface, whereby between the grounding attachment part and the structure or component a seal is fixed, so that the grounding contact surface and the surface of the structure or the component on which the grounding contact surface rests, is designed in a sealed manner relative to the surrounding area and/or the grounding contact is designed as a grounding contact as described above. 
     
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         [0024]    An illustrative embodiment of the invention is more closely described below with reference to the following illustrations. 
           [0025]      FIG. 1  provides a cross-section of a grounding contact attached to a structure in accordance with an embodiment of the present invention. 
           [0026]      FIG. 2  provides a perspective view of the grounding contact of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    In  FIGS. 1 and 2  a grounding contact  1 , formed in accordance with an embodiment of the present invention, for the grounding of a structure  16  made of metal, in particular, steel is shown. The structure  16  for example, depicts a steel structure and requires the grounding contact  1  for grounding in order to avoid damage to persons and goods when there is electricity because the grounding can discharge the electricity. 
         [0028]    The grounding contact  1  features a grounding attachment part  2 . The grounding attachment  2  consists of solid steel or copper and has a blind hole  5  and a contact piece  23  with a male thread  24  on the outside as shown in  FIG. 1 . A lug  21 , which is connected to a ground wire  22 , is slid onto the contact piece  23 . Here, the lug  21  is secured with a nut  25  with a female thread to the grounding attachment part  2 . Thus, male thread  24  on the contact piece  23  or the remaining contact surfaces of the lug  21  on the grounding attachment part  2  is made available as a contact surface  20  for contacting the lug  21  with the grounding attachment part  2  for example. 
         [0029]    The blind hole  5  has only one blind hole opening  15 . From the blind hole  5  only the blind hole opening  15  leads into the grounding attachment part  2 . The blind hole  5  has two different diameters, so that a level  6  appears on the blind hole  5 . The upper end of the blind hole  5  is provided with a female thread  14 . The grounding contact  1  is for grounding the structure  16  or a component  17  of the structure  16 , for example a wall  18  or a beam  19 . In  FIG. 1  the structure  16  or the component  17  is shown only partially. The structure  16  or the component  17 , for example, is made of steel or aluminum. Prior to the fixing of the grounding contact  1  a blind hole  26 , for example, with drilling, must initially be incorporated in the structure  16 . Subsequently, in the range of the blind hole  16  on one face  28  of the structure  16 , on which the grounding attachment part  2  is subsequently placed, an existing protective coating is to be removed. Notwithstanding this, a through-hole  27  can be incorporated into the structure  16  which in  FIG. 1  is represented by dashed lines. Subsequently, a cartridge-fired pin  4  is inserted into the blind hole  26  or in the through hole  27  and connected with the structure  16 . For example, the cartridge-fired pin  4  may be soldered to the blind hole  26  of the structure  16 . 
         [0030]    The grounding attachment  2  has a grounding contact surface  3  to be placed on the structure  16  or component  17 . Also, in the area of the grounding contact surface  3  the grounding attachment part  2  is provided with a groove  11  formed as a annular groove  12 . In the annular groove  12 , a sealing ring  10  is inserted as a seal  9 . In the illustrated embodiment, the sealing ring  10  consists of an elastic material, such as rubber or plastic material. For attaching, the grounding attachment part  2  is attached to the cartridge-fired pin  4 , which are already applied to the structure  16  with a support ring  7  and the sealing ring  8 , in that the pin  4  is screwed into the blind hole  5  of the grounding attachment part  2 . In this case, the cartridge-fired pin  4  in the area of its upper end features a male thread  13  as shown in  FIG. 1 . The grounding attachment part  2  can be connected to the cartridge-fired pin  4  with the help of male thread  13  on the cartridge-fired pin  4  and the female thread  14  on the blind hole  5  by a screwing action. In this manner, the grounding attachment  2  is screwed on to the cartridge-fired pin  4  until the grounding contact surface  3  of the grounding attachment part  2  rests on the surface  28  of the structure  16  or the component  17  which results in a pretension force between the grounding contact surface  3  and the surface  28  of the structure  16 . 
         [0031]    The seal  9  is introduced into the annular groove  12  so that before screwing on the grounding attachment  2  to the cartridge-fired pin  4  the sealing ring  10  is slightly protruding from the annular groove  12 . Thus, by the tightening of the grounding attachment part  2  to the pin  4  and the pretension force associated between the grounding contact surface  3  and the surface  28  of the structure  16  or the component  17 , the sealing ring  10  is elastically tensioned. The sealing ring  10 , thereby completely surrounds the grounding contact surface  3  inside the sealing ring  10 , thereby ensuring a complete seal between the grounding contact surface  3  and the surface  28  of the structure  16 , on which the grounding contact surface  3  rests. 
         [0032]    In the illustrated embodiment, the grounding attachment part  2  is made of solid material in one piece or is produced in one piece, so that in blind hole  5  there are no channels or openings leading to the blind hole  5 . Thereby the area between the grounding contact surface  3  and the surface  28  of structure  16  is completely and permanently sealed, because no fluids, especially liquids such as water, can enter this region. If the cartridge-fired pin  4  is mounted to a through hole  27  instead of the blind hole  26 , it is necessary, in order to maintain a seal, to seal through hole  27  completely, for example by arranging an additional seal in the cartridge-fired pin  4  and the structure  16  or component  17  of the structure  16  at the other end of the through hole  27  on which a grounding attachment part  2  is not fixed (not shown). 
         [0033]    There are significant advantages in connection with an inventive grounding contact formed in accordance with aspects of the present invention, such as grounding contact  1 . After securing the grounding contact  1  to the structure  16 , the area between the grounding contact surface  3  and the surface  28  of the structure  16 , on which the grounding contact surface  3  rests, is completely and permanently sealed, because on one hand the completely encircling resilient seal ring  10  is arranged between the grounding attachment part  2  and the structure  16  and, on the other hand, there are no openings or channels present on the grounding attachment part  2  which lead from the area of the grounding contact  1  into the blind hole  5 .