Patent Publication Number: US-8541708-B2

Title: Button switch

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a button switch. 
     2. Description of the Prior Art 
     A button switch is widely used to switch on/off a machine. A conventional button switch is composed of a button portion and a switch portion. The button switch can be a type of single button or a type of multiple buttons according to the number of the buttons on the button portion. The type of single button means the button portion only has a button. When in use, the user can press the button to switch on the switch portion and press the button again to switch off the switch portion. The type of multiple buttons means the button switch has at least one start button and one stop button which are used to start and stop the switch portion. 
     No matter what type of button switch, it has the shortcoming to restart the machine. This may cause an accident. For example, when the working machine is stopped for emergent maintenance, the operator may touch the start button unexpectedly, which results in damage of the working machine or injury of the operator. Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve this problem. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a button switch which comprises a main body, a start button and a stop button. The main body comprises a switch member. The switch member has a start portion and a stop portion. The start button is disposed on the main body to drive the start portion. The stop button is disposed on the main body to drive the stop portion. The stop button has a first position and a second position. In a normal state, the stop button is located at the first position and doesn&#39;t drive the stop portion. When the stop button is pressed the first time, the stop button is moved from the first position to the second position to drive the stop portion. When the stop button is pressed the second time, the stop button is returned to the first position. 
     The button switch of the present invention enforces the operator to press the stop button again after the stop button is pressed the first time, so that the stop button is returned to the first position and then the start button is pressed to start the switch member, preventing the operator to press the start button unexpectedly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view according to a preferred embodiment of the present invention; 
         FIG. 2  is an exploded view according to the preferred embodiment of the present invention; 
         FIG. 3  is a cross-sectional view according to the preferred embodiment of the present invention; 
         FIG. 4  is an enlarged sectional view showing the stop button in the first position according to the preferred embodiment of the present invention; 
         FIG. 5  is an enlarged sectional view showing the stop button in the second position according to the preferred embodiment of the present invention; 
         FIG. 6  is an enlarged sectional view showing the stop button to drive the stop portion of the switch member according to the preferred embodiment of the present invention; 
         FIG. 7  is an enlarged sectional view showing the limit unit before operated according to the preferred embodiment of the present invention; and 
         FIG. 8  is an enlarged sectional view showing the limit unit after operated according to the preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings. 
     As shown in  FIG. 1  to  FIG. 4 , a button switch  100  according to a preferred embodiment of the present invention comprises a main body  10 , a start button  20 , an outer casing  30 , a stop button  40 , and a limit unit  50 . 
     The main body  10  comprises an upper part  11 , a lower part  12 , a chamber  13  between the upper part  11  and the lower part  12 , and a switch member  14  received in the chamber  13 . The switch member  14  has a start portion  141  and a stop portion  142  to start and stop the switch member  14 , respectively. When the stop portion  142  is activated, the start portion  141  is unable to start the switch member  14 . The upper part  11  has a top end formed with a first recess  15  and a second recess  16 . The upper part  11  further has an accommodation trough  17  at a central portion thereof and a through hole  18  in the bottom of the accommodation trough  17 . The main body  1  further comprises a seal ring  19  on the periphery of the second recess  16  as well as at the junction of the upper part  11  and the lower part  12 . 
     The start button  20  is disposed in the first recess  15 , and comprises a protruding pole  21  extending from the bottom thereof and inserting in the main body  10 . The protruding pole  21  is connected with a start member  22 . The start member  22  has one end which is located opposite to the protruding pole  21  and against the start portion  141  of the switch member  14  for driving the start portion  141  of the switch member  14 . A spring  23  is provided between the start button  20  and the first recess  15 , so that the start button has a homing function. 
     The outer casing  30  is disposed in the second recess  16  of the main body  10  and on top of the stop button  40 . The outer casing  30  has a bottom provided with a protrusion  31  close to the stop button  40  and a plurality of circular poles  32 . Each circular pole  32  is fitted with a spring  33  and elastically against the stop button  40 . 
     The stop button  40  is disposed in the accommodation trough  17 . The stop button  40  comprises a guide rod  41  which is axially disposed relative to the through hole  18 . One end of the guide rod  41  is formed with a press plate  42  facing the outer casing  30 . The press plate  42  has a concave top surface  421  corresponding to and leaning against the protrusion  31 , such that the guide rod  41  is connected with the outer casing  30 . Another end of the guide rod  41  is defined as a positioning end  411 . The positioning end  411  is located in the through hole  18  and connected with a stop member  43 . The stop member  43  has one end which is located opposite to the guide rod  41  and selectively against the stop portion  142  of the switch member  14 , so that the guide  41  is connected with the stop portion  142 . As shown in  FIG. 4 , the guide rod  41  comprises a fixed toothed portion  44  on a side wall thereof, a block portion  45  below the fixed toothed portion  44 , and a rotatable ring  46  between the fixed toothed portion  44  and the block portion  45 . The rotatable ring  46  has a movable toothed portion  461  to engage with the fixed toothed portion  44 . A spring  47  is provided between the block portion  45  and the accommodation trough  17  of the main body  10 . An inner wall of the accommodation trough  17  of the main body  10  has a plurality of guide grooves  171  corresponding to the fixed toothed portion  44  and the movable toothed portion  461  and a positioning toothed portion  172  between every two of the guide grooves  171 . The positioning toothed portion  172  is disposed close to an open end of the relative guide groove  171 . Thus, the stop button  40  has a first position as shown in  FIG. 4  and a second position as shown in  FIG. 5 . When the stop button  40  is located at the first position, the fixed toothed portion  44  and the movable toothed portion  461  will be in the guide grooves  171 . The positioning end  411  of the guide rod  41  is received in the through hole  18 , such that the stop member  43  won&#39;t drive the stop portion  142  of the switch member  14 . When the stop button  30  is pressed the first time, the guide rod  41  will be moved outward toward the through hole  18 , as shown in  FIG. 5  and  FIG. 6 . The positioning end  411  is moved out of the through hole  18 , and the stop member  43  is linked to move downward and to press the stop portion  142  of the switch member  14 . The rotatable ring  46  is turned an angle for the movable toothed portion  461  to engage with the fixed toothed portion  172 , such that the guide rod  41  won&#39;t be returned to its original position by the spring  47  and the stop button  40  has the second position. 
     The limit unit  50  is disposed at one side of the main body  10  close to the start button  20 . The limit unit  50  comprises a lock set  50 . One end of the lock set  51  is connected with a limit member  52 . The lock set  51  is started with a key  53  to turn the limit member  52  to be located between the start button  20  and the start portion  141  of the switch member  14 , such that the start button  20  cannot start the start portion  141 . 
     Referring to  FIG. 3 ,  FIG. 4 ,  FIG. 5  and  FIG. 6 , the button switch  100  is mounted on an apparatus, such as a working machine, to start/stop the apparatus. In a normal state, the stop button  40  is located at the first position, as shown in  FIG. 4 , and doesn&#39;t drive the stop portion  142  of the switch member  14 . Therefore, the operator can direct press the start button  20  to bring the start member  22  to press the start portion  141  of the switch member  14  downward to start the apparatus. When the operator wants to stop the apparatus, he/she can press the outer casing  30  downward to drive the stop button  40 . At this time, the stop button  40  is moved from the first position to the second position as shown in  FIG. 5 . The stop member  43  presses the stop portion  142  of the switch member  14  to stop the apparatus. In the meanwhile, the movable toothed portion  261  engages with the fixed toothed portion  172 . Thus, the guide rod  41  cannot be returned to the first position by the spring  47 , and the stop member  43  continuously presses the stop portion  142  of the switch member  14  to limit the start portion  141 , so that the switch member  14  cannot be started. When there is an emergency for the apparatus to be maintained, the operator won&#39;t touch the start button  20  unexpectedly to start the apparatus, providing a protection to the apparatus and the operator. When the operator wants to start the apparatus again, he/she just presses the outer casing  30  again to drive the stop button  40 . The rotatable ring  36  will be driven by the fixed toothed portion  44  to move downward and guided by the positioning toothed portion  172  to be in guide grooves  171  again. The guide rod  41  is moved upward by the elasticity of the spring  47 , and the stop button  40  is returned to the first position, namely, the start button  20  can start the switch member  14  again. It is noted that when there is an emergency, the operator is always flurried and cannot press the outer casing  30  exactly. Through the protrusion  31  of the outer casing  30  and the concave top surface  421  of the stop button  40 , the stop button  40  can be pressed to drive the stop portion  142  of the switch member  14  even though only a portion of the outer casing  30  is pressed. This can avoid any accidents caused by the reason that the operator doesn&#39;t press the outer casing  30  exactly. 
       FIG. 7  and  FIG. 8  are schematic views showing the limit unit according to the preferred embodiment of the present invention. Through the limit unit  50 , the operator can turn the lock set  51  with the key  53  after the start button  20  is pressed. The limit member  52  is turned to be located between the start button  20  and the start portion  141  of the switch member  14 , so that the start button  20  cannot start the start portion  141 . Thus, after the apparatus is stopped, a person who is familiar with the button switch  100  of the present invention cannot restart the apparatus unintentionally, providing a dual-protection effect. 
     Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.