Patent Publication Number: US-7592560-B1

Title: Button device

Description:
BACKGROUND 
   1. Field of the Invention 
   The present invention relates to switches, and particularly to a button device used as switch in electronic devices. 
   2. Description of the Related Art 
   Push buttons are used as input units or switch units in electronic devices, such as mobile phones, remote controllers, cameras, or the like. However, push buttons commonly deflect to one side or another when pressed, preventing a keystroke from being registered. 
   SUMMARY 
   An exemplary button device includes a cover and a push button. The cover includes a main body with an opening defined therein, two spaced blocks, and a post extending from the main body between the blocks. The push button includes a positioning portion with a through hole defined therein for extension of the post, a pressing portion with a key top accommodated in the opening, a connecting portion for connecting the pressing portion to the positioning portion, and two wings stretching from opposite edges of the positioning portion adjacent to the connecting portion into a space between the blocks and the main body respectively. The positioning portion forms a protrusion which resists against the main body and separates the push button from the main body. 
   Other advantages and novel features of the present invention will become more apparent from the following detailed description of exemplary embodiments when taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an isometric view of an inverted cover of a button device, according to an exemplary embodiment. 
       FIG. 2  is an enlarged isometric view of a push button of the button device. 
       FIG. 3  is a cross-sectional view of an assembly of the button device, taken along lines III-III of  FIG. 1  and  FIG. 2 . 
   

   DETAILED DESCRIPTION 
   Referring to  FIGS. 1 through 3 , a button device in accordance with an exemplary embodiment of the present invention includes a cover  100 , and a push button  200  positioned on the cover  100 . The cover  100  can be a panel of an electronic device (not shown). 
   The cover  100  comprises a main body  110 , two spaced posts  120  and  130  perpendicularly extending from the main body  110 , and two spaced blocks  150 , adjacent to the two opposite sides of the main body  110  respectively. The post  120  is disposed midway between the blocks  150 . The main body  110  defines an opening  112  therein, disposed between the posts  120 ,  130  but nearer to the post  130 . The posts  120  and  130 , and the blocks  150  are disposed at an inner side of the cover  100 . In the embodiment, the main body  110  forms a recessed portion  114  at the inner side thereof for partially accommodating the push button  200  to minimize dimensions of the button device. 
   The push button  200  comprises a positioning portion  220 , a pressing portion  230 , a connecting portion  240  for connecting the pressing portion  230  to the positioning portion  220 , and two wings  250  stretching respectively from opposite edges of the positioning portion  220  adjacent to the connecting portion  240 . 
   The positioning portion  220  defines a through hole  222  midway between the wings  250 , for extension of the post  120  of the cover  100  therethrough. The positioning portion  220  forms a first protrusion  228 , which resists the inner side of the main body  110  and separates the push button  200  from the main body  110  after the push button  200  is assembled to the cover  100 . In the embodiment, the first protrusion  228  is a rib. 
   The pressing portion  230  has a key top  232  formed thereon near the connecting portion  240 , and a pressing projection  234  perpendicularly extending from the key top  232  ( FIG. 3 ). The key top  232  is accommodated in the opening  112  of the main body  110 , for access by users. The pressing projection  234  is used for pressing a spring (not shown) so that a keystroke may be registered. The pressing portion  230  defines a cutout  236  at an end thereof distant from the connecting portion  240 , for extension therethrough of the post  130  of the cover  100 . A second protrusion  238  is formed at the end of the pressing portion  230 . In this embodiment, the second protrusion  238  is a rib parallel to the first protrusion  228  and is bisected by the cutout  236 . The post  130  being in the cutout  238  allows the pressing portion  230  to move like the arm of a lever, and prevents the pressing portion  230  from deflecting to the side and missing the spring. The cutout  236  of the embodiment can be replaced by an elongated hole in other embodiments. 
   Each of the wings  250  comprises a tilted end  252  outwardly stretched relative to the positioning portion  220 . The tilted ends  252  of the wings  250  are positioned to resist against the blocks  150  by sliding the tilted ends  252  into a space between the main body  210  and the blocks  150 ; therefore, the push button  200  is positioned to the cover  100 . The post  120  being in the through hole  222  prevents the positioning portion  220  from being deflected when pressed, after the tilted ends  252  of the wings  250  are mounted in the space between the blocks  150  to connect the push button  200  with the cover  100 . 
   In the embodiment, the push button  200  operates as a lever, and the tilted ends  252  function as a fulcrum of the push button  200 . The pressing portion  230  can be depressed to cause a keystroke to be registered. Upon release, the pressing portion  230  is restored to its original location, by means of a force exerted on the first protrusion  224  by the main body  110 . The second protrusion  238  prevents the pressing portion  230  from being excessively restored. Therefore, the pressing portion  230  can be more precisely restored. 
   It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.