Abstract:
A pushbutton assembly includes a housing and a button slidable with respect to the housing. A passage is formed in the housing which is provided with a projection formed in the passage and a slanted face on top of the projection. A positioning disk is pivotally connected to the projection and has a positioning hole. A positioning rod is pivotally connected to the button and has a bent received in the positioning hole of the positioning disk in such a way that movement of the button drives the bent to reciprocally move from a first position to a second position.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a pushbutton assembly, and more particularly to a pushbutton assembly having a positioning rod rotatably connected to a button and a positioning disk pivotally received in a housing of the pushbutton assembly and having a positioning hole defined in the positioning disk to receive therein a bent of the positioning rod such that repeated up and down movement of the button allows the bent to be positioned at a first position and a second position within the positioning hole to accomplish the designed purpose of the pushbutton assembly. 
     BACKGROUND OF THE INVENTION 
     With reference to FIGS. 1 to  3 , a conventional pushbutton assembly is applied in a ball point pen. The ball point pen has a barrel  403 , a button  406 , a cap  404 , a first sleeve  407  and a second sleeve  409 . The barrel  403  is provided with a spring  402  and a core  401  received in the barrel  403 . The cap  404  has positioning slots  405  defined in an inner periphery of the cap  404  and bars  4051  each alternately formed between, two adjacent positioning slots  405 . Each bar  4051  has an inclined top face. 
     The first sleeve  407  has first bosses  408  formed around an outer periphery of the first sleeve  407  to correspond to the positioning slots  405  of the cap  404 . The second sleeve  409  has second bosses  410  formed on an outer periphery of the second sleeve  409  to correspond to the positioning slots  405  of the cap  404 . After the cap  404  is assembled with the barrel  403 , the button  406  and the first sleeve  407  are slidable relative to the barrel  404 . After the assembly of the pen, the user pushes the button  406 , the downward movement of the first sleeve  407  drives the second sleeve  409  to rotate, allowing the second bosses  410  to about the top face of the bar  4051  to extend the core  401  out of the barrel, as shown in FIG.  2 . However, when the user pushes the button  406  again, the second bosses  410  are thus received in the corresponding positioning slots  405 , allowing the core  401  to be retracted in the barrel  403 , as shown in FIG.  3 . In this type of pushbutton assembly, parts are loosely connected to one another. Thus, every movement of the button  406  creates a lot of friction between parts and that wears out the engaged faces of the parts. From the foregoing description, it is noted that this type of conventional pushbutton assembly not suitable for sophisticated electronic components. 
     U.S. Pat. No. 4,167,720; U.S. Pat. No. 4,937,548; U.S. Pat. No. 5,223,813 U.S. Pat. No. 5,451,729; U.S. Pat. No. 5,558,211 are numerous patents related to a pushbutton assembly, which all suffer from the following shortcomings: 
     1. Too many linking parts are involved in a single movement, causing a complex process to accomplish a single purpose and a non-real-time action; and 
     2. Because the quantity of the parts to accomplish a single action is large, possibility of malfunction is great and the quality of coupling between parts is low. 
     With reference to FIG. 4, a second conventional pushbutton assembly is shown to have a button  501  and a housing  506 . 
     The button  501  is mounted on top of a body (not numbered) having a V-shaped protrusion  503  which is formed on a bottom of a channel  502  and has a lowermost point (a). The channel  502  has a lowermost point (b). A positioning rod  504  has a first end inserted into the through hole  507  in the housing  506  and a second end  505  extending into the channel  502 . A spring  508  is employed to provide a resilience to the button  501  and to ensure that the second end of the positioning rod  502  to abut an inner face of the channel  502 . 
     When the user presses the button  501 , the second end of the positioning rod  504  moves from point (a) to point (b). When the user pushes the button  501  again, the second end of the positioning rod  504  moves from point (b) to point (a). After the pushbutton assembly is used for a period of time, the resilience of the spring  508  is deteriorated, and the engagement of the second end  505  of the positioning rod  504  with the inner face of the channel  502  is not secured. Therefore, it is noted that the second end  505  of the positioning rod  504  may deviate from point (a) if the resilience form the spring  508  is not enough. Another shortcoming from the insufficient resilience is that the contact  510  of the electrical plate  509  may not engage with the contact  512  of the pin  511  properly and thus causes malfunction. 
     Accordingly, the conventional pushbutton assembly uses too many parts so that the cost is high and the possibility of having malfunction is thus high. 
     To overcome the shortcomings, the present invention tends to provide an improved pushbutton assembly to solve the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide an improved pushbutton assembly having a positioning rod rotatably connected to a button and a positioning disk pivotally received in a housing of the pushbutton assembly and having a positioning hole defined in the positioning disk to receive therein a bent of the positioning rod such that repeated up and down movement of the button allows the bent to be positioned at a first position and a second position within the positioning hole to accomplish the designed purpose of the pushbutton assembly. 
     Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded perspective view of a conventional pushbutton assembly used in a ball point pen; 
     FIG. 2 is a schematic view showing that the core extends out of the barrel by the pushbutton assembly in FIG. 1; 
     FIG. 3 is a schematic view showing that the core is retracted in the barrel by the pushbutton assembly in FIG. 1; 
     FIG. 4 is an exploded perspective view of a conventional pushbutton assembly used in an electronic device; 
     FIG. 5 is an exploded perspective view of the pushbutton assembly of the present invention; 
     FIG. 6 is a perspective view of the housing of the pushbutton assembly, wherein in order to show the inner structure of the housing, the view is slightly slanted; 
     FIG. 7 is a schematic view showing that the button is not pressed; 
     FIG. 8 is a schematic view showing that the downward movement of the button forces the positioning rod to move and the positioning disk to pivot; 
     FIG. 9 is a schematic view showing that the button is pressed and secured; 
     FIG. 10 is a schematic view showing that the positioning rod is released by the positioning disk and is ready to return to its original position; 
     FIG. 11 is a schematic view of another embodiment of the present invention; 
     FIG. 12 is a schematic view showing the structure of the pushbutton assembly in FIG. 11 when the button is pressed; and 
     FIG. 13 is a schematic view showing that after the button of the embodiment in FIG. 11 is pressed, the positioning rod is positioned. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to FIGS. 5 and 6, the pushbutton assembly of the present invention includes a button  1 , a positioning rod  2  and a housing  3 . 
     The button  1  has extensions  11  integrally formed on a bottom face of the button  1 . A positioning hook  12  extends from the bottom face of the button  1 . A first resilient element  13  (preferably a spring) is received in the button  1  and an assembly rod  14  is formed on a side face of the button  1  and has an assembly hole  141 . 
     The positioning rod  2  has a through hole  21  defined in a first distal end of the positioning rod  2  and a bent  22  integrally formed on a second distal end of the positioning rod  2 . A first bolt  23  is provided to extend through a second resilient element  24 , the through hole  21  of the positioning rod  2  and the assembly hole  141  of the assembly rod  14 . 
     The housing  3  has cutouts  31  defined in an outer face of the housing  3  to correspond to the extensions  11  at least one hole  32  defined to correspond to the positioning hook  12 , a passage  33  defined in the housing  3  and having a projection  330  with a slanted face  331 , an assembly slot  34  in the housing  3  and a positioning disk  35  pivotally connected to the housing  3  and having a positioning hole  351 , a first hole  352  defined to correspond to a second bolt  36  and the assembly slot  34  and a second hole  353  defined to correspond to a distal end of a third resilient element  37 . As can be seen in FIGS. 5 and 7, the positioning hole  351  is formed through the positioning disk  35  which is positioned and assembled in front of the passage  33  and the bent  22  is disposed in the passage  33  through the positioning hole  351 . 
     With reference to FIGS. 5-7 when the pushbutton assembly of the present invention is assembled, the first resilient element  13  is first received in the button  1  and the positioning rod  2  is pivotally connected to the button  1  by the first bolt  23  with the bent  22  extending downward relative to the button  1 . Then the extensions  11  extend into the cutouts  31  and the positioning hook  12  extends into the corresponding hole  32  to secure the connection between the housing  3  and the button  1 . After the positioning disk  35  is pivotally connected to the housing  3  by the second bolt  36  which extends through the first hole  352  and the assembly slot  34 , the positioning disk  35  is able to pivot using the second bolt  36  as the central axis. It is noted from the drawings that the bent  22  of the positioning rod  2  extends into the positioning hole  351  and one distal end of the third resilient element  37  extends into the second hole  353  of the positioning disk  35  and the other distal end of the third resilient element  37  securely abuts an inner face of the housing  3 . Therefore, it is noted that the positioning disk  35  is urged by the third resilient element  37  to be maintained in a position 
     When the button  1  is not pressed, as shown in FIG. 7, the button  1  extends out of the housing  3 . When the button  1  is pressed, the positioning rod  2  is driven to move accordingly. With reference to FIG. 6, it should be noted that below the slanted face  331  of the projection  330  is a recessed channel  332  which can not be easily shown and is not labelled on FIGS. 7-10. The bent  22  slides over the slanted face  331  in the passage  33 , which allows the bent  22  to move leftward (from the viewer&#39;s direction) to abut a side face defining the positioning hole  351  so that the positioning disk  35  pivots to the left, as shown in FIG.  8 . As the positioning disk  35  pivots to the left and the positioning rod  2  moves downwards, the bent  22  slides into the recessed channel  332 . If the user releases the button  1 , the bent  22  rests in the recessed channel  332  and is prevented from moving above point (A) in the positioning hole  351  because the area near point (A) of the positioning disk  35  and the slanted face  331  have blocked the upward passage as can be seen from FIG.  9 . Therefore, the button  1  is at a second (depressed) position, as shown in FIG.  9 . 
     When the user presses the button  1  again, the bent  22  forces the positioning disk  35  to pivot to the right. As the positioning rod  2  is pressed downwards, the bent  22  slides off the recessed channel  332  into a space by the side of the slanted face  331  as shown in FIG.  10 . Consequently, the bent  22  is released from point (A) and thus the button  1  is pushed upward by the first resilient element  13 . The bent  22  is then blocked in the positioning hole  351  near point (B), as shown in FIG.  7 . 
     Another embodiment of the present invention is that the positioning rod  2  may be provided in the housing  3  and the positioning disk  35  and the passage  33  be formed in the button  1 , which also accomplishes the pre-designed purpose. 
     With reference to FIG. 11, the alternative embodiment of the present invention having the positioning rod  2  provided in the housing  3  and the positioning disk  35  and the passage  33  formed in the button  1  is shown. As can be seen in FIG. 11, the button  1  is formed with a projection which has a slanted face  331  formed in the bottom. 
     The positioning rod  2  is pivotally connected to the housing  3  by the second bolt  36  which extends through the second resilient element  24 , the through hole  21  and into the assembly hole  141  of the assembly rod  14  that is formed inside the housing  3 . After the assembly of the positioning rod  2 , the bent  22  extends upward with respect to the housing  3 . 
     The positioning disk  35  is pivotally connected to the button  1  by the first bolt  23  which extends through the first hole  352  of the positioning disk  35  and into the assembly slot  34  defined inside the button  1 . The first resilient element  13  is still mounted inside the button  1  to be sandwiched between the button  1  and the housing  3  to provide a recovery force to the button  1  so that after the button  1  is pressed relative to the housing  3 , the first resilient element  13  is able to push the button  1  back to its original position. When the assembly is finished, the bent  22  is received in the positioning hole  351  of the positioning disk  35 . 
     With reference to FIGS. 12 and 13, when the button  1  starts to move downward relative to the housing  3 , the positioning disk  35  is driven to move accordingly. It should also be noted that in this embodiment, the recessed channel  332  shown in FIG. 5 becomes a recessed channel above the slanted face  331  in FIGS. 12 and 13. The bent  22  slides over the slanted face  331  in the passage  33 , which allows the bent  22  to move to abut a side face defining the positioning hole  351  so that the positioning disk  35  pivots to the right. As the positioning disk  35  pivots to the right, the bent  22  slides into the recessed channel. If the user releases the button  1 , the bent  22  rests in the recessed channel and is blocked near point (A) in the positioning hole  35 l by the area near point (A) of the positioning disk  35  and the slanted face  331  as can be seen from FIG. 12 which shows that the button  1  is at a second (depressed) position. If the user presses the button  1  again, the bent  22  forces the positioning disk  35  to pivot to the left. As the positioning disk  5  pivots to the left, the bent  22  slides off the recessed channel into a space by the side of the slanted face  331  as shown in FIG.  13 . Consequently, the bent  22  is released from point (A) and thus the button  1  is pushed upward by the first resilient element  13 . The bent  22  is then blocked in the positioning hole  351  near point (B) and the pushbutton is returned to the position shown in FIG.  11 . 
     It is to be understood, however, that even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, 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.