Abstract:
A solar cell panel has a pair of superimposed plates, and one or more solar energy cells sandwiched between the plates. A connector for making electrical connection to an external connection member in use of the panel is mounted on the periphery of the superimposed plates. To achieve a compact and simple construction, one-piece strip metal electrical conductor members have first ends located between the superimposed plates and electrically connected to the solar energy cells and second ends which protrude from the periphery and are held in a housing of the connector. The second ends act as electrical terminals.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The present invention relates to a solar cell panel for electricity generation using solar energy, having a connector incorporated therein.  
           [0003]    2. Description of Related Art  
           [0004]    [0004]FIG. 5 shows one form of known solar cell panel  100  having a connector  110  for connecting with an external connector  120  provided on the end of cable K. The connector  110  is firmly fixed on the outer periphery of the panel  100  which is made of a pair of glass sheets  101 , between which a plurality of solar cell elements  102  in a two-dimensional array are sandwiched. The solar cell elements  102  are electrically connected mutually in series or in parallel between the pair of glass sheets  101  by tape-like conductors  103 , which are electrically connected with the connector  110  through a connecting sheet  105 .  
           [0005]    In the connecting sheet  105  a pair of thin ribbon-like conductors  106 , which are arranged in parallel at suitable spacing, is sandwiched by insulation sheets  107 . The conductors  103  from the solar cell elements  102  are electrically connected by soldering, etc. to the respective conductors  106 .  
           [0006]    Tape-like conductors  109  are electrically connected by soldering, etc. to the conductors  106  in the end area of the connecting sheet  105 , and extend to the outer peripheral area of the panel  100  to be connected to the connector  110 .  
           [0007]    When the external connector  120  on the cable K is connected with the connector  110 , the solar cell panel  100  is electrically connected to an external load or storage battery.  
           [0008]    Generally, the electrical connection in connector  110  and external connector  120  is performed by locking together of positive and negative terminals inside the connectors. Thus a negative and a positive terminal are arranged in the housing of the connector  110 , and electrically connected by for example soldering to the conductors  109  which extend from the outer peripheral area of the panel  100 . However, space is required for connecting the conductors  109  and the negative terminal and the positive terminal inside the connector  110 , which causes a problem that the whole shape of the connector  110  becomes large. This is unfavorable for design reasons, because the connector  110  itself is conspicuous when the solar cell panel is installed on the window frame or on the roof of a building, etc. If a large frame body is installed around the panel  100  to hide the connector  110 , the effective area contributing to solar energy electricity generation is decreased.  
           [0009]    U.S. Pat. No. 4,283,106 shows a single-pole connector mountable on a solar panel by engagement of a slot on the connector housing with a cut-out in a peripheral projecting flange of the panel. A strip-shape conductor protrudes from between superimposed sheets of the panel and is soldered to an exposed base member of a folded metal terminal construction mounted in the connector housing. The arrangement is space-consuming, since both the flange and the connector project above the plane of the panel. Soldering of the conductor to the terminal construction is inconvenient.  
         SUMMARY OF THE INVENTION  
         [0010]    An object of the present invention is to provide a connector of compact structure on a solar cell panel.  
           [0011]    According to the invention, there is provided a solar cell panel having a pair of superimposed plates and at least one solar energy cell sandwiched between the plates. A connector, used in making electrical connection to an external connection member in use of the solar cell, is mounted on the superimposed plates at their periphery. At least one one-piece electrical conductor member has a first end located between the superimposed plates and electrically connected to the solar energy cell and a second end which protrudes from the periphery of the plates and is received and held in a housing of the connector where it constitutes an electrical terminal for making electrical connection with the external connection member in use. It is preferred that the electrical conductor is of ribbon-like or strip shape. Typically there are two such conductor members, providing terminals of opposite polarity in the connector housing.  
           [0012]    This construction permits a compact and simple connector to be provided at the periphery of the panel.  
           [0013]    Preferably, for a compact arrangement, the one-piece electrical conductor member, or each such electrical member, is bent twice, outside the superimposed plates, first to extend in a first direction which is the thickness direction of the superimposed members and secondly to extend in a second direction substantially parallel to an edge of the panel, so as to constitute a pair of parallel spaced terminals of the connector extending in the second direction.  
           [0014]    A bypass diode may easily be incorporated, in the housing of the connector, between the two conductors.  
           [0015]    Preferably, for locking of the conductor member, or each conductor member, the housing has a locking structure that engages the electrical conductor member and holds the electrical conductor member in its longitudinal position in the housing.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    An embodiment of the invention will now be described by way of non-limitative example with reference to the accompanying drawings, in which:  
         [0017]    [0017]FIG. 1 is a partially sectional side view of a solar cell panel which is an embodiment of the present invention showing the connected condition of an external connector and a connector of the panel;  
         [0018]    [0018]FIG. 2 is a partially sectional side view of the connector shown in FIG. 1 on a larger scale;  
         [0019]    [0019]FIG. 3 is a partially sectional plan view of the connector shown in FIG. 1 and FIG. 2;  
         [0020]    [0020]FIG. 4 is an end view of the connector shown in FIG. 1; and  
         [0021]    [0021]FIG. 5 is a side view showing a connector of a known solar cell panel, described above.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0022]    A solar cell panel  100  having a connector  1  which is an embodiment of the present invention is shown in FIGS.  1  to  4 , in which the solar cell panel  100  itself is the same as in FIG. 5 except for conductor  109  and connector  110 , so that repetition of its description is not needed here. FIGS.  1  to  3  are described as a matter of convenience with reference to a forward direction which is to the right and a backward direction which is to the left (see arrows in FIGS. 2 and 3).  
         [0023]    As shown in FIGS.  1  to  4 , a connector  1  is installed on the outer periphery of panel  100  to be able to be connected with an external connector  50  which is installed at the end of cable K. The ends of the conductors  30  which extend out from the outer periphery of the panel  100  are held in an insulating housing  2  of the connector  1  and act as terminals  30   b  that connect with terminals  55  inside the external connector  50 . The conductors  30  may be planar, meaning that they have a cross section with a greater width than thickness. For example, a ratio of the thickness of the conductors  30  to the width of the conductors  30  may be in a range of from about 1:2 to about 1:20; or from about 1:4 to about 1:12; or from about 1:6 to about 1:10. An advantage of planar conductors  30  is that, to accommodate increased electrical current, the conductors  30  need only be increased in width, and their thickness does not need to be increased. This avoids increasing the overall thickness of the solar cell panel  100 . However, it should be appreciated that in some applications of this invention, the conductors  30  may be round or square, for example, rather than planar.  
         [0024]    The external connector  50  may be a two terminal connector installed at the end of a two core cable K, having a housing  51  as shown in FIG. 1 containing two connecting terminals  55  arranged spaced apart and aligned and electrically connected with the respective cores of the external cable K. Each terminal  55  is in use connected with the respective terminal  30   b  by forcing the planar terminal  30   b  between a resilient tongue  57  and an abutment seat  58  of a connecting portion  56  of the terminal  55 . The whole terminal  55  may be formed of cut and bent metal sheet. The abutment seat  58  may be formed by a side flange part which is folded over so that its edge projects upwardly towards the tongue  57 .  
         [0025]    The housing  51  has a portion  60  extending towards its tip side having a hook  60   a  which engages in a latching manner with a recess  3   a  of the housing  2  of the connector  1 .  
         [0026]    Each one-piece conductor  30  may be formed by bending a metal strip member made by punching out a thin metal sheet, and has at one end a connecting area  30   a  sandwiched together with connecting sheet  105  between a pair of glass sheets  101  of the panel  100 . The glass sheets  101  are superimposed with adhesive or filler between them which supports the connecting area  30   a  of each conductor  30  in the required position between them.  
         [0027]    The connecting areas  30   a  of the conductors  30  are arranged between the glass sheets  101  aligned at required intervals along the edge of panel  100  and are electrically connected, e.g. by soldering, to the thin ribbon-like conductors  106  in the connecting sheet  105 , which are connected to the leads  103  of the solar cell elements  102  in the connecting sheet  105 .  
         [0028]    As shown in FIG. 3, the portions of the conductors  30  protruding from the outer periphery of the panel  100  may be bent twice, to extend first in the thickness direction of the panel  100  and secondly in a direction parallel to the edge surface of the panel  100  (i.e., a direction perpendicular to the thickness direction of the panel  100 ), whereby in housing  2  they extend in a spaced and aligned manner as the respective terminals  30   b . The terminals  30   b  may be coplanar. The housing  2  may have a terminal-supporting region  10  having projections  13   a  which engage in recesses  30   c  cut in the terminals  30   b , to locate and support the terminals  30   b  in the backwards/forward direction.  
         [0029]    The housing  2  of the connector is flat, and of rectangular cross-section, as seen in FIG. 4, in which a portion of the sheets  101  are shown diagrammatically. At its rear end, the housing  1  has a cavity region  15  (see FIG. 3) bounded by the housing wall containing the bent portions of the conductors  30 , and having a slit  16  in its base on the panel  100 , at a location corresponding to the gap between the pair of glass sheets  101 , so that the conductors  30  can extend from between the sheets directly into the cavity  15 . In the cavity  15  may be a diode D, for effecting electrical bypass of the panel  100 , which is required under certain operating conditions. The diode D may be connected by leads DL, to the respective conductors  30 , e.g. by soldering. A sheet-shape closure  19  closes the end opening of the cavity  15  at the rear side of the connector, in order to prevent access of water.  
         [0030]    In the terminal holding region  10 , the housing  2  has a barrier wall  11  with through holes  12 , through which pass the respective terminals  30   b . Thus the terminals  30   b  are retained in their aligned position substantially parallel to the edge of the panel  100 .  
         [0031]    Adjacent the through holes  12 , as seen in FIG. 3, are the hook-like members  13  of the housing  2 , extending in the backward direction and having the projections  13   a  at their rear ends, to engage with the recesses  30   c  of the terminals  30   b . The members  13  have a flat shape, and are elastically deformable in the transverse direction. The extremity of each member  13  has a surface  13   b  inclined with respect to the insertion direction of the terminal  30   b , so that the terminal  30   b  pushes the member  13  aside until the projection  13   a  is engaged with the recess  30   c  by the spring back of the member  13 .  
         [0032]    The forward portion of the housing  2  has an open ended cavity  7  that receives the housing  51  of the connector  50 . The rearward part of this cavity  7  is divided by a partition  6   a  to form a pair of terminal insertion passages  6 . The terminals  30   b  extend along these terminal insertion passages  6 , and receive and engage the terminals  55  of the external connector  50 .  
         [0033]    A thick sheet gasket  9 , made of resilient material such as rubber, with through holes  9   a  corresponding to the terminal insertion passages  6 , may be arranged against a shoulder  7   a  of the cavity  7 . This gasket  9  is engaged by the housing  51  of the external connector  50 , in the connected position of the connectors  1  and  50 , to prevent access of water to the connected terminals.  
         [0034]    Support members  20  for the terminals  30   b  may be provided, which are fully slidable along the respective terminal receiving passages  6 , and have through-holes  21  through which the terminals  30   b  pass. The supports  20  serve to maintain the alignment position of the terminals  30   b . A resilient member, such as a coil spring  25 , may be provided between the base of each terminal receiving passage  6  and the support  20 , to urge the support  20  in the forward direction. A stop (not shown) may retain the support  20  in the passage  6 .  
         [0035]    When the external connector  50  is connected to the connector  2  the tip end of the connecting portion  56  of each terminal  55  of the connector  50  engages the respective terminal support  20  and pushes it in the backward direction. Since at the moment of engagement the terminal  30   b  is held by the support  20  in the correct position to be inserted between the tongue  57  and the abutment seat  58  of the terminal  55 , the risk of deformation of the terminal  30   b  by the terminal  55  is avoided.  
         [0036]    At its upper face, the housing  2  has a groove  3  which receives the extending portion  60  of the housing  51  of the external connector  50 , so that the hook end  60   a  engages with the correspondingly shaped recess  3   a  to lock the connectors together.  
         [0037]    To assemble the solar panel and connector construction shown in FIGS.  1  to  4 , first the end portion  30   a  of the conductors  30  are connected by soldering to the conductors  106  of the connecting sheet  105 . Then the areas  30   a  are sandwiched between the glass sheets  101 . The conductors  30  are bent as described at their region protruding from the panel  100 . The diode D is connected between the conductors  30 . The conductors  30  are then inserted into the housing  2  from the rear end of the slit  16  and through the through holes  12  into the required position where they are locked by the members  13 . The terminal supports  20  may be inserted into the connector  1  before the terminals  30   b  or afterwards.  
         [0038]    Alternatively, the connector  1  may be assembled in advance, and the connecting portions  30   a  projecting from the slit  16  are inserted and connected to the conductors  106  of the connecting sheet  105 , e.g. by soldering, before being sandwiched between the glass sheets  101 .  
         [0039]    The housing  2 , with its sealing end closure  19 , is adhesively bonded to the peripheral edge faces of the sheets  101 , so that the cavity  15  is sealed to the sheets  101 .  
         [0040]    As shown in FIG. 4, the arrangement of the bent conductors  30  extending out of the periphery of the panel  100  into the flat connector housing  2  provides a compact shape for the whole construction, as compared with that of FIG. 5. Because the conductor  30  is bent first in the thickness direction of the panel  100  and then in a direction parallel to the periphery of the panel  100 , a compact arrangement is achieved, and the external connector  50  is joined to the connector  1  in a direction parallel to the edge of the panel  100 . The two terminals  30   b  may be coplanar, to make the construction compact. However, within the scope of the invention, the terminals  30   b  may extend perpendicularly to the edge direction of the panel  100 , so that the connection with the external connector  50  is made in this perpendicular direction.  
         [0041]    As FIG. 4 shows, the connector  1  may be located between the planes of the exterior main faces of the panel.  
         [0042]    As shown in the drawings, the bypass diode D can be easily incorporated into the solar cell panel construction.  
         [0043]    The locking of the terminal  30   b  into position by engagement of the projection  13   a  with the recess  30   c  effectively retains the terminal in the correct position, even against the fitting force of the terminal  55  of the external connector  50 .  
         [0044]    The return force of the springs  25  ensures continued engagement of the hook  60   a  with the corresponding recess  3   a.    
         [0045]    While the invention has been illustrated by an exemplary embodiment described above, many equivalent modifications and variations will be apparent to those skilled in the art when given this disclosure. Accordingly, the exemplary embodiment of the invention set forth above is considered to be illustrative and not limiting. Various changes to the described embodiment may be made without departing from the spirit and scope of the invention.