Patent Publication Number: US-9847191-B2

Title: Switch having improved moveable contact

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to an switch, and more particularly to a switch having an improved moveable contact. 
     2. Description of Related Arts 
     The traditional switch includes an insulative housing with a receiving space therein, a fixed contact set retained in the housing, a moveable contact set located above the fixed contact, and a cover positioned upon the housing. The movable contact set includes a pair of dome-shaped contacts stacked with each other and commonly restrainedly positioned in the housing. The manual operation feels relatively dull. 
     A new switch having a better operation feeling is desired. 
     SUMMARY OF THE INVENTION 
     Accordingly, an object of the present invention is to provide a switch with a better operation feeling. 
     To achieve the above object, an electrical switch includes an insulative housing forming a receiving space therein, a fixed contact set retained in the housing, a movable contact set located above the fixed contact set, and a cover mounted upon the housing, wherein the moveable contact set further includes at least three outwardly and downwardly extending protrusions on a periphery so as to support up-and-down movement of the moveable contact set during operation with a superior feeling. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an assembled perspective view of a preferred embodiment of an electrical switch according o the invention; 
         FIG. 2  is an exploded perspective view of the switch of  FIG. 1 ; 
         FIG. 3  is a further exploded perspective view of the switch of  FIG. 2 ; 
         FIG. 4  is a further exploded perspective of the switch of  FIG. 3 ; 
         FIG. 5  is another exploded perspective view of the switch of  FIG. 4 ; 
         FIG. 6  is a perspective view of the moveable contact; and 
         FIG. 7  is a cross-sectional view of the switch of  FIG. 1   
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiment of the present invention. 
     Referring to  FIGS. 1-7 , an electrical switch  100  includes an insulative housing  110  forming a receiving space (illustrated later), a fixed contact set (illustrated later) retained in the housing  110 , a moveable contact set (illustrated later) located above the fixed contact set, and an insulative cover  140  mounted to the housing  110 . 
     The housing  110  having includes a bottom wall  111  and four side walls composed of opposite front wall  112  and rear wall  113  and opposite two side walls  114  linking said opposite front wall  112  and rear wall  113 . The aforementioned receiving space is formed by the bottom wall  111 , the opposite front wall  112  and rear wall  113 , and the opposite two side walls  114 . The housing  110  further includes the platform  115  raised up from the bottom wall  111  so as to divide the receiving space into the first/upper receiving space  116  and the second/lower receiving space  117 . 
     The fixed contact set includes a first fixed contact  121  and the second fixed contact  122 , of which both are integrally formed with the bottom wall  111  via an insert-molding process. The first fixed contact  121  and the second fixed contact  122  have soldering section exposed upon the bottom surface of the housing for mounting to a printed circuit board. The moveable contact set up and down moveable between opposite upper and lower positions, include a first moveable contact  131  and a second moveable contact  132  stacked with each other and commonly received within the second receiving space  117 . Both the first moveable contact  131  and the second moveable contact  132  are of a dome shape around a central region, and each includes further four outwardly and downwardly extending protrusions  133  arranged along a periphery at equal intervals and laterally confront the platform  115 . In an unused condition, corresponding abutment periphery edges (not labeled) of two of the protrusions  133  constantly mechanically and electrically connect to the second fixed contact  122  while the whole moveable contact set is spaced from the first fixed contact  121 ; in a used condition in which the moveable contact set is downwardly pressed, the central region of the moveable contact set downwardly electrically and mechanically connects the circular region (not labeled) of the first fixed contact  121  so as to electrically connect the first fixed contact  121  and the second fixed contact  122 . 
     The cover  140  made from elastic material for deformation, includes a top plate  141 , a protruding button  142  in the central region, and four side walls  143  downwardly extending from four side edges of the top plate  141  and into the corresponding grooves (not labeled) between the platform  115  and the corresponding four side walls of the housing  110  wherein the cover  140  is essentially received within the first receiving space  116 . 
     The second receiving space  117  forms a contour in compliance with that of the moveable contact set, including a central circular portion to receive the corresponding dome shape and four outwardly extending portions along four different radial directions which are essentially directed to opposite corners of the housing  110  to receive the corresponding protrusions  133 , respectively. Understandably, in the traditional switch, the dome-shaped moveable contact set is essentially supported via the whole periphery thereof during up-and-down operation so as to result in compression/deformation circumferentially in a relative dull manner. Differently, in the instant invention, only via the four spaced downwardly and outwardly extending protrusions  133  supporting instead of the whole peripheral support, the whole moveable contact set is deformed and compressed in a delicate manner with a better and clear operation feeling wherein due to the four protrusions  133  retained in the corresponding outwardly extending portion of the second receiving space  117 , no rotation of the moveable contact set in the second receiving space  117  will occur. Thus, a reliable click operation is achieved. Notably, instead of using the protrusions  133 , alternately the anti-rotation function may be performed by forming a plurality of notches in the periphery of the central region of the moveable contact set, and the housing  110  forms a plurality of dimples engaged within the corresponding notches, respectively. Moreover, because the moveable contact set is supported via only the protrusions  133 , there should be at least three protrusions at equal intervals for stable support during deformation of the moveable contact set. 
     While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as described in the appended claims.