Patent Publication Number: US-6036538-A

Title: Securing mechanism used in miniature Christmas light bulb sockets

Description:
BACKGROUND OF THE INVENTION 
     Most of the Christmas light bulb strings achieve their decorative purpose by means of hanging. To enhance their attraction and show their uniqueness, usually the light bulb strings hang on a support frame with special shapes like characters or design patterns. Thus, the light bulb strings display, after being powered, the character or pattern of the support frame. The conventional method uses simply a hanging connection, without effective fixation. That arrangement often leads to loosening. Furthermore, the loosened light bulbs make the pattern or character appear to be incomplete. It is therefore desirable to improve the conventional structure. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing problems, the primary object of the present invention is to provide a securing mechanism for Christmas light bulb sockets that employs a specially designed locking means to overcome the deficiency of conventional light bulb strings. 
     Now the features and advantages of the present invention will be described below in detail with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view showing a miniature light bulb socket according to the present invention; 
     FIG. 2 is an exploded view illustrating the securing means of the socket of FIG. 1; 
     FIG. 3 is a cross sectional view of the socket assembly according to the present invention; 
     FIG. 4 shows a second embodiment of the securing means according to the present invention; and 
     FIG. 5 shows a third embodiment of the securing means according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to the accompanying drawings, the present invention comprises a miniature light bulb socket 1 and a fastener 2. A light bulb holder receiving a light bulb therein (not shown) is inserted into the socket 1, which is similar to the conventional method and thus will not be explained in further detail. The socket 1 is provided with a pair of longitudinal guide rails 11 and a plurality of horizontal transverse ribs 12 between the two guide rails 11 on each of two sides of the socket 1. Each transverse rib 12 has a triangular cross section with an inclined top side and a horizontal bottom side. The fastener 2 has a U-shaped resilient body with horizontal locking ribs 21 formed on two inner wall surfaces, which ribs also have a triangular cross section with a horizontal top side and an inclined bottom side. 
     In use, the U-shaped fastener 2 extends over a decorative support frame 3 with the two side ends thereof respectively extending between the two longitudinal guide rails 11 on each of two sides of light bulb socket 1. In the meantime, the locking ribs 21 of the fastener 2 interlock with the transverse ribs 12 of the socket 1 under the resilient restoring force of the fastener 2 to form a firm attachment. With such an arrangement, the socket 1 can be disposed at any position along the support frame 3 with a desired inclined angle. Thus, the socket 1 can achieve an expected effect by maintaining its location. A Christmas light bulb string with all of the sockets having such securing means can be easily attached to a support frame, providing an optimal decorative effect. 
     The foregoing configuration of transverse ribs 12 and locking ribs 21 can facilitate a quick unidirectional engagement between a fastener 2 and a socket 1, which is not easy to separate due to the restoring force of the resilient sides of the fastener. In addition, the two longitudinal rails 11 on each of two sides of socket 1 confine the respective sides of the U-shaped fastener 2, so that the fastener 2 is not movable. 
     The support frame 3 may include two parallel locking plates 31 formed on one side surface of support frame 3, as shown in FIG. 4. The parallel locking plates hold on to the socket 1 by means of hook portions 32 formed on the free end of each locking plate for locking engagement with the transverse ribs 12 of the socket 1. Consequently, that arrangement can obtain the same securing effect as the first embodiment. FIG. 5 shows another embodiment of the securing mechanism, in which the guide rails and the transverse ribs are disposed in a direction perpendicular to the previous example. By that arrangement, the light bulb on the socket faces toward one side. This will enhance the illumination effect.