Patent Publication Number: US-6336821-B1

Title: Connector for use in solar generator

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a connector provided in a line connecting a solar generator (or battery) to an electric device. 
     As disclosed in e.g. Japanese patent publication 8-222062, an ordinary connector comprises a rod-shaped female terminal and a rod-shaped male terminal inserted coaxially into tubular insulating resin housings, respectively. By inserting the male terminal into the female terminal, they are electrically connected together. 
     A solar generator generates electricity of about 50 amperes at 900 volts. Connectors used with such a generator have to withstand huge amounts of electricity. Thus, resistance to voltage of about 5000 V or over is required for such connectors. For this purpose, not only the terminals but the housings are required to have a sufficient coupling strength. 
     An object of the invention is to provide a connector that has a sufficient coupling strength. 
     SUMMARY OF THE INVENTION 
     According to this invention, there is provided an electrical connector for use in a solar generator comprising first and second tubular insulating resin housings, a rod-shaped female terminal coaxially inserted in the first housing, and a rod-shaped male terminal inserted in the second housing and adapted to be inserted into the female terminal so as to be electrically connected to the female terminal, the first housing having outer and inner tubular portions formed with axially corrugated inner and outer surfaces, respectively, defining an annular groove therebetween, the second housing having an annular tip having axially corrugated inner and outer surfaces adapted to engage the axially corrugated inner and outer surfaces of the first housing when the second housing is inserted into the first housing so that the annular tip is inserted into the annular groove. 
     According to the present invention, both of the male and female housings have corrugated surfaces thereon for increased coupling strength. 
     Also, the contact member having a radially convexed surface is fitted on the male terminal for increased contact pressure with the female terminal. 
     Because the female housing has a double tube configuration, the coupling force and the water sealability are increased. 
     According to this invention, a radially outwardly convexed annular contact member is fitted on the male terminal so as to be pressed into close contact with the inner wall of the female terminal for power connection when the male terminal is inserted into the female terminal. 
     Because the tip of the male terminal is covered with resin, shortcircuiting due to contact with some conductive material is avoided. 
     The contact member may comprise a plurality of separate radially convexed pieces. This increases the springiness and contact pressure and facilitates manufacture. 
     The combination of corrugations on the male and female housings with the provision of the contact member increases the coupling strength and contact pressure. 
     If the male and female housings are made of soft resin or synthetic rubber, the terminals should preferably have their tips covered with hard resin for insulation. This prevents a short circuit even if the soft housing gets bent so that the terminal is exposed. 
    
    
     Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a connector embodying the invention; 
     FIG. 2 is a partially cutaway perspective view of a portion of a female terminal of the connector of FIG. 1; 
     FIG. 3 is a similar view of a portion of a male terminal of the connector of FIG. 1; 
     FIG. 4 is a partial enlarged view of FIG. 1; 
     FIGS. 5A and 5B are views showing how a contact member for the male terminal is formed; 
     FIG. 6 is a partially cutaway exploded perspective view of a second embodiment; 
     FIG. 7 is a sectional view of a third embodiment; 
     FIG. 8 is a partially cutaway perspective view of a portion of a female terminal of the embodiment of FIG. 7; and 
     FIGS. 9A and 9B are a partially cutaway front view and a plan view of a fourth embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1-5 show a connector embodying the present invention. Like conventional connectors, it comprises a rod-shaped female terminal  10  and a rod-shaped male terminal  30  inserted coaxially into tubular insulating housings  20  and  40  made of a soft resin (or rubber), respectively. Power cords  1  are connected to the respective terminals  10  and  30  by inserting and pressing. 
     A potbelly-shaped contact member  31  is fitted on a portion of the male terminal  30  near its tip. The contact member  31  is formed by rolling a spring plate formed with slits  32  at equal intervals (FIG. 5A) into the shape of a potbelly (FIG. 5B) so that portions  33  between the slits  32  are arcuately curved outwardly (i.e., convexed). When the male terminal  30  is inserted into the female terminal  10  as shown in FIGS. 1 and 4, the outwardly convexed portions  33  are brought into close contact with the inner wall of the female terminal  10 , so that the terminals  10  and  30  are electrically coupled together with high contact pressure. 
     An insulating cap  34  made of a hard nonconductive resin is put on the tip of the male terminal  30  to prevent shortcircuiting due to inadvertent contact with an electrically conductive material. 
     The female housing  20  has outer and inner tubular portions  21  and  22  having axially corrugated inner and outer surfaces  23 , respectively, defining an annular deep groove therebetween. 
     The male housing  40  has an annular tip having axially corrugated inner and outer surfaces  41 . When the annular tip of the male housing  40  is inserted into the annular groove of the female housing  20  as shown in FIGS. 1 and 4, the corrugated surfaces  41  of the male housing  40  engage the corrugated surfaces  23  of the female housing  20 , thus strongly coupling the housings  20  and  40  together. 
     FIG. 6 shows a second embodiment. The contact member  33  of this embodiment comprises a plurality of separate contact pieces having both ends received in grooves  35  formed in the male terminal  30  so as to be bent arcuately outwardly except their straight ends. But the ends may be not straight but be arcuate and continuous with the central portion. This is true for the first embodiment, too. 
     FIGS. 7 and 8 show a third embodiment in which an insulating cap  11  made of a hard resin is put on the tip of the female terminal  10 , too. The cap  11  keeps the tip of the female terminal  10  insulated even if the female housing  20  has its tip peeled. 
     Although single-core connectors are shown as embodiments, the present invention is applicable to connectors with a plurality of cores such as a double-core connector as shown in FIGS. 9A and 9B. 
     The connector according to the invention can strongly connect two lines together and be useful as a connector for power connection in a solar generator.