Patent Publication Number: US-2010108375-A1

Title: Connection box for solar module

Description:
FIELD OF THE INVENTION 
     The present invention relates to a connection box. More particularly this invention concerns a connection box for a solar panel. 
     BACKGROUND OF THE INVENTION 
     A standard connection box for a solar panel has a base mounted on solar panel and forming a compartment for circuit elements. A solar-panel output line feeds electricity generated by the panel into the box and a feed cable is connected in the box to the solar-panel output line and in turn feeds the electricity to the network or user. A cover closes the base and a seal between the cover and the base hermetically seals the compartment they define. 
     Such connection boxes are known, for example, from U.S. Pat. No. 4,623,753, DE 20 2005 008 385, or US 2005/0161080. Here the cover has a collar extending toward the base of the connection box. A groove is formed along the peripheral surface of the collar, in which a sealing ring, in particular an O-ring, is inserted. Upon placement of the cover on the base of the connection box, the sealing ring seals the compartment against external influences, in particular dirt and moisture, by engagement of the seal between the floor of the groove and the outer flank of the annular groove. 
     In addition to the opening closable by the cover, the base has in its wall forming the compartment further holes or cutouts that are provided for the feed cables. These openings are also closed to the external environment using suitable seals. The seals are supported on the lateral surface of the feed cable. 
     The seals are entirely usable in regard to their action, but are in need of improvement in their design and configuration in regard to manufacturing which is automated as is completely as possible. 
     OBJECTS OF THE INVENTION 
     It is therefore an object of the present invention to provide an improved connection box for a solar module. 
     Another object is the provision of such an improved connection box for a solar module that overcomes the above-given disadvantages, in particular that is improved in regard to automated manufacturing. 
     SUMMARY OF THE INVENTION 
     A box for connecting an output line of a solar panel with a feed cable has according to the invention a base mountable on the solar panel, formed with at least one cutout through which the feed cable passes, and having a generally planar floor and around the floor a seal seat open orthogonally in one direction of the floor. A cover is engageable oppositely of the direction is with the base to from therewith a compartment. Functional elements are provided in the compartment, A seal in the seat is engaged between the base and the cover. 
     The base of the connection box is typically equipped with circuit elements, in particular contacts and bridge diodes, in a direction orthogonal to its floor. It is a significant advantage if the seal may also be inserted in the same direction according to the solution according to the invention, because this significantly reduces the manufacturing effort. 
     An embodiment which is characterized in that the shared seal of the cover and the base additionally seals the connection-box-side cable routing cutout is especially preferred. 
     Automated manufacturing is further simplified by this advantageous refinement. Only one seal is still required to seal the cover and the side cable routing cutout. Not only does this optimize assembly but also the combination of components which were separate until now, so that the number of the assembly steps may be reduced overall. 
     To this end, the seal is provided with a cable routing opening for the feed cable. The seal function of the seal is ensured in that the cable routing opening of the seal has a smaller diameter than the diameter of the feed cable and the outer surface of the feed cable inserted in the region of the cable routing opening is used as a sealing surface by the seal. 
     In order to also be able to install the feed cable in a direction orthogonal to the base of the base, an embodiment is proposed which is characterized in that the seal is constructed in two parts in the region of its cable routing opening such that a lower part of the feed cable is insertable into the cable routing opening in the orthogonal direction to the base of the base. Then an insert part of the seal is fitted in the recess over the cable. Automated manufacturing is made significantly easier by this refinement of the assembly direction of the feed cable, which was parallel to the base of the base until now. 
     In the above-mentioned embodiment, it is advantageous if the second part of the seal can be placed on the first part via a tongue-and-groove connection. 
     In general, it is provided that the base forms the holder or seat for the seal. In particular, the base has an outer peripheral wall and an inner peripheral wall between which a peripheral annular gap is formed that forms the holder or seat for the seal. The seal function of the seal may be improved further in that the seal forms a lip extending toward the cover and projecting beyond the outer peripheral wall toward the cover, in particular if the cover is formed with a groove for accommodating the sealing lip on the base. Furthermore, it is considered that the seal forms a recess for accommodating a cover-side collar. In combination, an embodiment results here which is characterized in that the cover-side collar, the recess of the seal, the sealing lip, and the cover-side groove are situated in sequence in the direction of the compartment such that a labyrinth seal is provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which: 
         FIG. 1  is an exploded perspective view from above of the box according to the invention; 
         FIG. 2  is a perspective view from above of the assembled base of the box; 
         FIG. 3  is a view like  FIG. 1  of another box according to the invention; 
         FIG. 4  is a perspective view from above of the  FIG. 3  seal; 
         FIG. 5  is an exploded perspective view from above of the seal assembly; and 
         FIG. 6  is a section taken along line VI-VI of  FIG. 1 . 
     
    
    
     SPECIFIC DESCRIPTION 
     As seen in the drawing a connection box  10  has a cover  11  and a base  12 . The base  12  has an outer side wall  13  projecting upward toward the cover and an inner side wall  15  extending parallel to and spaced from the base  12  by an annular gap  14 . (The references to “up” and “down” being purely for convenience of description, since the box is often mounted inverted on the generally downwardly facing back face of a solar panel.) 
     Two opposite outer surfaces of the side wall  13  are formed with locking lug guide ridges  16  that are interrupted by tool-engagement formations  17 . The locking lug guide webs  16  form a seat in which wedge-shaped locking projections  18  are formed on the outer surfaces of the side wall  13 . 
     Feed cables  20  are routed into the interior of the connection box  10  through cable holes or cutouts  19  in the side wall  13 . The stripped inner ends of these cables  20  are used to contact solar-panel output conductors  21  in a chamber  22  of the base  12 . The feed cables  20  carry contacts  23  that are crimped on their stripped wire ends for electrical connection to the panel-output conductors  21 . 
     A vent  24  connects the compartment  22  to the external environment via holes  25  provided in the side wall  13 . The formation of condensed water and super or subatmospheric pressures are thus prevented in the compartment  22 . A bridge diode  26  is in an electrical connection with the two the feed cables  20  shown in the illustrated embodiment. Parts such as the bridge diode  26 , the vent  24 , or the clamping contacts  23  are considered functional elements. 
     A seal  27  formed with a lip  28  projecting toward the cover is fitted to the base gap  14 . When the cover  11  is placed on the base, the lip  28  presses against bottom and side surfaces of the cover. Furthermore, the seal  27  forms cable routing openings  29  through which the feed cables  20  pass into the chamber  22 . 
     The cable openings  29  have a diameter that is slightly smaller than the cable outside diameter, so that the inner edges of the cable openings press against the side surfaces of the feed cables  20  to form seals. In connection with the sealing lip  28 , the compartment  22  is protected against external influences, in particular moisture and contamination, with the aid of only a single seal  27 . 
     The cover  11  forms locking lugs  30  that project downward toward the base  12  and that fit with the locking lug guide webs  16  and the locking projections  18  and anchor the cover  11  solidly on the base  12  when the box  10  is closed, on opposing edges. Using the tool-engagement formation  17 , a tool which spreads the locking lugs  30  may be introduced into the region of the locking projections  18  in order to open the connection box  10 . 
     The essential advantage in the embodiment according to  FIGS. 1 and 2  of the invention is the arrangement of the seal  27  in an annular chamber  14  that is open toward the cover  11  and/or is plane-parallel to a generally rectangular and planar floor  31  of the base  12  and that is used as a holder or seat for the seal  27 . This advantageously allows the assembly direction for the diverse circuit elements, which is oriented orthogonally to a plane of the flat floor  31 , to also be used for the insertion of the seal  27  into the base  12 . In the present example, in particular the bridge diode  26  and the contact of the clamping contact  23 , which is placed in the overlap region of wire end of the feed cable  20  and the panel-output conductor  21 , are mounted in the above-mentioned orthogonal direction. 
     A second embodiment of the invention is shown in  FIGS. 3 through 5  in which features that are functionally identical to those of  FIGS. 1 and 2  bear the same reference numerals. 
     In contrast to the preceding embodiment, the seal is formed in two parts. In the region of the cable routing openings  29 , the seal  27  has an approximately U-shaped recess into which a seal insert  32  may be introduced. The separation plane  33  between seal  27  and seal insert  32  runs parallel to the base  31  and cuts through the cable routing openings in the seal  27  such that the seal  27  and the seal insert  32  form corresponding, approximately semicircular cable routing openings. 
     In the region of the recess, the recess edge of the seal  27  is formed with grooves  34  in which springs  35  of the seal insert  32  engage and hold the seal insert  32  in the seal  27 . The tongue-and-groove arrangement is precisely fitted such that penetration of moisture and dirt is not possible along the partition planes between the seal  27  and the seal insert  32 . 
     In  FIG. 6  the seal  27  has a recess  36  in which a collar  37  of the cover  11  engages. This is adjacent on the seal side to the sealing lip  28 , which extends beyond the height of the side wall  13  of the base  12  extending toward the cover  11  and is inserted in a cover-side seal groove  38 . The arrangement of the recess  36  with the collar  37  and the sealing lip  28  having corresponding sealing groove  38 , which is sequential toward the compartment  22 , forms a labyrinth-type seal arrangement. 
     In summary, a connection box  10  is disclosed whose advantageous holder for a seal  27  allows an assembly direction of the seal  27  that is orthogonal to the base  31  and is distinctly advantageous from an assembly viewpoint. By dividing the seal  27  in the region of its cable routing openings  29 , the assembly direction oriented orthogonally to the base  31  may also be implemented for insertion of the feed cables  20  into the compartment  22 . The connection box  10  according to the invention thus significantly improves the automated manufacturing in its embodiments