Patent Publication Number: US-5421742-A

Title: Electric lamp base system

Description:
BACKGROUND OF THE INVENTION 
     A conventional electric lamp base system shown in FIGS. 5 and 6 includes a cylindrical socket 10, two conductors 20, 30, and a cap 40 combined together. The socket 10 has a threaded portion 101 in an inner wall for screwing with a lamp. One of two conductor 20 is vertically fixed on an inner wall of the socket 10 having a pointed lower end 201, and the other conductor 30 is fixed laterally on a bottom of the socket 10, having a pointed projection 301 from one end. Two lead wires 50 are deposited laterally through under the bottom of the socket 10, and the pointed ends 201, 301 of the two conductors 20, 30 prick in the two lead wires to conduct electricity. The cap 40 has a projecting-up portion 401 to fit in a center hole 103 in the bottom of the socket 10 and to press up tightly the two lead wires 50 when the cap 40 is fixed to close on the bottom of the socket 10 from under. When this system is in manufacturing process, one end of the conductor 30 is bent down to contact one pole of the lamp. But the two conductors 20, 30 are often found to be in contact with each other to cause short-circuit made by careless or erroneous work of workers, and thus causing probable fire. 
     SUMMARY OF THE INVENTION 
     An electric lamp base system in the present invention includes a conductor fitted in an inner wall of a cylindrical socket and contacting with a circumferential threaded portion of a lamp and its bottom end inserting in a lead wire to conduct electricity, and another conductor fitted straight in a hole in a bottom of the socket and having its upper end bent to contact with a bottom end of a lamp and its bottom end inserting in another lead wire to conduct electricity. The two lead wires are put through a straight horizontal groove in the bottom of the socket and presses firmly by a diametrical straight portion on the bottom of a cap closed on the bottom of the socket from under. Consequently, the two conductors are located far from each other, without possibility of mutual contact to cause short-circuit. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention will be better understood by reference to the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of an electric lamp base system in the present invention; 
     FIG. 2 is a front cross-sectional view of the electric lamp base system in the present invention; 
     FIG. 3 is a side cross-sectional view of the electric lamp base system in the present invention; 
     FIG. 4 is an upper view of the electric lamp base system in the present invention; 
     FIG. 5 is a perspective view of a conventional electric lamp base system; and, 
     FIG. 6 is an upper view of the conventional electric lamp base system. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An electric lamp base system in the present invention, as shown in FIGS. 2 and 3, includes a socket 1, two conductors, a cap 4 combined together. The socket is provided with a threaded portion 11 for a lamp to screw with, a straight groove 12 and a position groove 121 extending laterally to both sides from the straight groove 12 in an inner wall for a conductor 2 to engage therein to be firmly positioned as shown in FIG. 4. A through hole 13 is also provided in a bottom of the socket 1, preferably in its center, for a rather short conductor 3 to engage therein. The two conductors 2 and 3 have respectively a lower end 21, 31 to insert in two lead wires. The socket i also has a straight horizontal groove 14 in the bottom for two lead wires to pass through therein, and a center hole 15 in the bottom portion for two upright walls 41 of a cap 4 to fit therein. The cap 4 has a diametrical straight projection 42 on an upper surface to press the two lead wires 5, 5 firmly, keeping the wires 5, 5 in place. 
     In assembling, as shown in FIGS. 2 and 3, the two conductors 2 and 3 are respectively deposited in the straight groove 12, and the hole 13 of the socket 1. Then the two lead wires 5 are inserted through the straight groove 14, and the projecting-up walls 41 of the cap 4 are put to fit in the center hole 15 and the diametrical projection 42 thereof fitting in the center hole 15 to press up the two lead wires 5 in its position. After that the lower ends 21, 31 of the conductors 2 and 3 are inserted in the two lead wires 5 for conducting electricity. 
     As seen from the above description, the two conductors 2 and 3 are provided to be located in such positions that they cannot contact with each other by any means, never causing short-circuit, and besides, their length can be made as short as possible to lower the cost and the prevent short-circuit caused by mutual contact. 
     While the preferred embodiments of the invention have been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications which may fall within the spirit and scope of the invention.