Patent Publication Number: US-8981244-B2

Title: Forward/backward rotation switching mechanism

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a switch structure applied in push switches, and more particularly to a forward/backward rotation switching mechanism. 
     2. Description of the Prior Art 
     “Switch” is a necessary mechanism for electrical equipments and electronic products, such as refrigerators, TVs, extension cords, computers, and video game consoles, all the aforesaid equipments and devices need the switch for turning on/off the power thereof. Push switch is the most conventional used switch. 
     Please refer to  FIG. 1 , there is shown a stereo view of a conventional push switch. As shown in  FIG. 1 , the conventional push switch  1 ′ is applied in an electric hand-held device for controlling the rotation of a motor, including: a trigger  10 ′, a sliding mechanism  11 ′, a first switching shaft  12 ′, a second switching shaft  13 ′, negative power connecting member  14 ′, a supporting member  15 ′, a connecting member  16 ′, a positive and negative terminals connecting module  18 ′, a positive power connecting member  19 ′, a forward/backward rotation switching mechanism  20 ′, a compensation type electronic control circuit  21 ′, a diode  22 ′, a stop member  17 , a first tension spring  24 ′, a second tension spring  25 ′, a first cover  231 ′, a second cover  232 ′, and a heat-sink  26 ′. 
     Continuously refer to  FIG. 1 , and please refer to  FIG. 2 ,  FIG. 3  and  FIG. 4 , there are shown a stereo view of the positive and negative terminals connecting module, an exploded view of the forward/backward rotation switching mechanism, and an assembly drawing of some parts of the conventional push switch. The positive and negative terminals connecting module  18 ′ includes a positive terminal  181 ′ and a negative terminal  182 ′, used for respectively connecting to a positive terminal and a negative terminal of the motor. In addition, the positive and negative terminals connecting module  18 ′ further includes a housing  183 ′ for accommodating the positive terminal  181 ′ and a negative terminal  182 ′. The forward/backward rotation switching mechanism  20 ′ includes a first switching member  201 ′ and a second switching member  202 ′, wherein the first switching member  201 ′ is initially contacted with the connecting member  16 ′ and the negative terminal  182 ′, and the second switching member  202 ′ is initially contacted with the positive power connecting member  19 ′ and the positive terminal  181 ′. 
     In the conventional push switch  1 ′, the rotation way of the motor can be defined by changing the contact of the first switching member  201 ′, the second switching member  202 ′, the positive terminal  181 ′, the negative terminal  182 ′, the connecting member  16 ′, and the positive power connecting member  19 ′. Moreover, according to the positive and negative terminals connecting module  18 ′, the forward/backward rotation switching mechanism  20 ′ further includes: a forward/backward rotation switching stem  205 ′, a switching stem fixing member  206 ′, a third compression spring set  203 ′, and a fourth compression spring set  204 ′. In which, the forward/backward rotation switching stem  205 ′ has a rear swing portion  2052 ′ and a front swing portion  2051 ′. The rear swing portion  2052 ′ is provided with a plurality of apertures  2053 ′ for combining with the first switching member  201 ′ and the second switching member  202 ′. Because the front swing portion  2051 ′ is pivotally connected with the rear swing portion  2052 ′, the rear swing portion  2052 ′ would oppositely move after pushing the front swing portion  2052 ′, such that the contact of the first switching member  201 ′, the second switching member  202 ′, the positive terminal  181 ′, the negative terminal  182 ′, the connecting member  16 ′, and the positive power connecting member  19 ′ can be changed. 
     Thus, by above descriptions, it is able to know that the conventional push switch  1 ′ can not only control the rotation of the motor, but also switch the motor to a forward rotation or a backward rotation; However, the conventional push switch  1 ′ still includes shortcomings and drawbacks as follows:
     (1) When being assembled, the first switching member  201 ′ and the second switching member  202 ′ are firstly inserted into the apertures  2053 ′ of the forward/backward rotation switching mechanism  20 ′, and then the first switching member  201 ′, the second switching member  202 ′ and the forward/backward rotation switching mechanism  20 ′ are directly put on the positive and negative terminals connecting module  18 ′; thus, because the first switching member  201 ′ and the second switching member  202 ′ does not be provided with any locking structures, the first switching member  201 ′ and the second switching member  202 ′ may fall out of the apertures  2053 ′ when the first switching member  201 ′, the second switching member  202 ′ and the forward/backward rotation switching mechanism  20 ′ are directly put on the positive and negative terminals connecting module  18 ′; that is a main problem when assembling the conventional push switch  1 ′.   (2) There has no any dust-off or anti-dust mechanism between the rear swing portion  2052 ′ and the front swing portion  2051 ′, so that, the external dust would be accumulated in the connection point of the rear swing portion  2052 ′ and the front swing portion  2051 ′, and eventually the forward/backward rotation switching stem  205 ′ cannot be operated normally.   (3) Moreover, in the conventional push switch  1 ′, although it can pushes the front swing portion  2052 ′ for easily switching and controlling the motor to make the forward rotation or the backward rotation, the rear swing portion  2052 ′ may break away from the fixing of the switching stem fixing member  206 ′ when being subject to an external force, and then the motor cannot be switched and controlled normally.   

     Accordingly, in view of the conventional push switch still have shortcomings and drawbacks, the inventor of the present application has made great efforts to make inventive research thereon and eventually provided a forward/backward rotation switching mechanism. 
     SUMMARY OF THE INVENTION 
     The first objective of the present invention is to provide a forward/backward rotation switching mechanism, in which each of terminal-housing grooves are provided with two terminal-locking portions and two first locking portions and two second locking portions are formed on corresponding contact terminals, respectively; therefore, after the contact terminals are assembled into the terminal-housing grooves, their locking portions would lock the terminal-locking portions, such that the contact terminals can be prevented from falling out of the terminal-housing grooves. 
     The second objective of the present invention is to provide a forward/backward rotation switching mechanism, in which a plurality of dust-off trenches are formed on the peripheral edges of a turntable for preventing from the dust accumulation between the turntable and a cover; therefore, even if the forward/backward rotation switching mechanism is used in an environment having a lot of dust, the turntable can still be turned around because the dust is ruled out by the dust-off trenches. 
     The third objective of the present invention is to provide a forward/backward rotation switching mechanism, in which the contact terminals and the turntable are assembled with a terminal-fixing body, and the terminal fixing body is fixed in the cover through a fixing ball and a return spring; thus, when the turn handle is forced to make the turntable rotate forwardly, the motor is switched and makes a forward rotation, meanwhile, unless forcing the turn handle to make the turntable rotate backwardly, the rotation way of the motor would not be influenced even if the switch device is subject to push or vibration made by external forces. 
     Accordingly, to achieve the objectives of the present invention, the inventor of the present invention provides a forward/backward rotation switching mechanism, which is adapted for being disposed in a switch device and used for assisting the switch device in controlling a forward rotation and a backward rotation of a motor, the forward/backward rotation switching mechanism comprising: 
     a cover, provided a turntable-corresponding recess on the top thereof, and a sliding groove is formed on the bottom surface of the turntable-corresponding recess; 
     a turntable, accommodated in the cover and opposite to the turntable-corresponding recess, and having a turn handle and an embedding block, wherein the turn handle is disposed in the sliding groove, and the embedding block comprises an embedding member and an inserting member; 
     a terminal-fixing body, comprising: a housing groove, having a first housing portion and a second housing portion, wherein the bottom of the embedding member and the inserting member are embedded into the first housing portion and the second housing portion, respectively; and two terminal-housing grooves; 
     a first contact terminal, disposed in one of the terminal-housing grooves of the terminal-fixing body; and 
     a second contact terminal, disposed in the other terminal-housing groove of the terminal-fixing body, wherein the terminal-fixing body may be driven to rotate by forcing to the turn handle and rotating the turntable, therefore the first contact terminal and the second contact terminal would contact with the terminals inside the switch device, and then the motor is switched and controlled to make the forward rotation or the backward rotation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use and advantages thereof will be best understood by referring to the following detailed description of an illustrative embodiment in conjunction with the accompanying drawings, wherein:: 
         FIG. 1  is a stereo view of a conventional push switch; 
         FIG. 2  is a stereo view of a positive and negative terminals connecting module; 
         FIG. 3  is an exploded view of a forward/backward rotation switching mechanism of the conventional push switch; 
         FIG. 4  is an assembly drawing of some parts of the conventional push switch; 
         FIG. 5  is a stereo view of a switch device provided with a forward/backward rotation switching mechanism introduced by the present invention; 
         FIG. 6  is an exploded view of the forward/backward rotation switching mechanism according to the present invention; 
         FIG. 7  is a stereo view of a cover and a turntable of the forward/backward rotation switching mechanism; 
         FIG. 8A  is a stereo view of a terminal-fixing body of the forward/backward rotation switching mechanism; and 
         FIG. 8B  is a second stereo view of the terminal-fixing body. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     To more clearly describe a forward/backward rotation switching mechanism according to the present invention, embodiments of the present invention will be described in detail with reference to the attached drawings hereinafter. 
     Please refer to  FIG. 5 , there is shown a stereo view of a switch device provided with a forward/backward rotation switching mechanism introduced by the present invention; moreover, please simultaneously refer to  FIG. 6 , which illustrates an exploded view of the forward/backward rotation switching mechanism introduced by the present invention. As shown in  FIG. 5  and  FIG. 6 , the forward/backward rotation switching mechanism  1  of the present invention is adapted for being disposed in a switch device  2  and used for assisting the switch device  2  in controlling a forward rotation and a backward rotation of a motor, the forward/backward rotation switching mechanism  1  includes: a cover  11 , a turntable  12 , a terminal-fixing body  13 , a first contact terminal  14 , a second contact terminal  15 , and a plurality of terminal springs  18 . 
     Referring to  FIG. 5  and  FIG. 6  again, and please refer to  FIG. 7 ,  FIG. 8A  and  FIG. 8B  simultaneously, there are respectively shown stereo views of the cover, the turntable and the terminal-fixing body. As shown in FIGs., the cover  11  includes: a turntable-corresponding recess  111 , two ball recesses  112 , a plurality of locking structures  113 , and a circuitous embedding opening  114 , wherein the turntable-corresponding recess  111  is formed on the top of the cover  11 , and a sliding groove  1111  is formed on the bottom surface of the turntable-corresponding recess  111 . The two ball recesses  112  are formed on the inner surface of the cover  11  and corresponding to the turntable-corresponding recess  111 , the locking structures  113  is formed on the edges of the cover  11  and used for locking the switch device  2 , and the circuitous embedding opening  114  is formed on the bottom of the turntable-corresponding recess  111 . 
     The turntable  12  is accommodated in the cover  11  and opposite to the turntable-corresponding recess  111 . The turntable  12  has a turn handle  121  and an embedding block  122 , wherein the turn handle  121  is disposed in the sliding groove  1111 , and the embedding block  122  includes an embedding member  1221  and an inserting member  1222 . Besides, the turntable  12  further includes a plurality of dust-off trenches  123 , which are formed on the peripheral edges of the turntable  12  for preventing from the dust accumulation between the turntable  12  and the cover  11 . So that, even if the forward/backward rotation switching mechanism  1  of the present invention is used in an environment having a lot of dust, the turntable  12  can still be turned around because the dust is ruled out by the dust-off trenches  123 . 
     Moreover, the terminal-fixing body  13  includes: a housing groove  131 , two terminal-housing grooves  132 , a ball housing  133 , and a plurality of spring-accommodating grooves  134 , wherein the housing groove  131  has a first housing portion  1311  and a second housing portion  1312 . When assembling this forward/backward rotation switching mechanism  1 , the top and the bottom of the embedding member  1221  are embedded into the circuitous embedding opening  114  and the housing portion  1311 , respectively; in addition, the inserting member  1222  is inserted into the second housing portion  1312 . In the present invention, the circuitous embedding opening  114  in the turntable-corresponding recess  111  has circuitous portions  1141  for lengthening the invasion path of the dust, such that the invading dust located between the turntable  12  and the cover  11  can be extremely effectively reduced. 
     Besides, the two terminal-housing grooves  132  of the terminal-fixing body  132  are used for accommodating the first contact terminal  14  and the second contact terminal  15 , and the ball housing  133  is used for housing the fixing ball  16  and the return spring  17 . In the operation of the forward/backward rotation switching mechanism  1 , the terminal-fixing body  13  may be driven to rotate by forcing to the turn handle  121  and rotating the turntable  12 , therefore the first contact terminal  14  and the second contact terminal  15  would contact with the terminals inside the switch device  2  for controlling the motor to make the forward rotation or the backward rotation. Moreover, because the return spring  17  is a compression spring, the fixing ball  16  would be pushed into the ball recess  112  by the return spring  17  when the terminal-fixing body  13  stops rotating, and then the terminal-fixing body  12  is fixed. 
     Furthermore, the spring-accommodating grooves  134  are formed on the bottom of the terminal-fixing body  13  for accommodating the terminal springs  18 , so as to make the terminal springs  18  opposite to the first contact terminal  14  and the second contact terminal  15  in the terminal-housing grooves  132 . Therefore, since the terminal springs  18  are also compression springs, the elastic force provided by the terminal springs  18  are able to make the first contact terminal  14  and the second contact terminal  15  contact with the terminals inside the switch device  2  tightly. 
     In addition, as shown in  FIG. 6  and  FIG. 8A , in order to prevent the first contact terminal  14  and the second contact terminal  15  from falling out of the terminal-housing grooves  132 , each of the terminal-housing grooves  132  are provided with two terminal-locking portions  1321  and two first locking portions  141  and two second locking portions  151  are formed on the first contact terminal  14  and the second contact terminal  15 , respectively. Thus, after the first contact terminal  14  and the second contact terminal  15  are assembled into the terminal-housing grooves  132 , their locking portions  141 ,  151  would lock the terminal-locking portions  1321 ; So that, the first contact terminal  14  and the second contact terminal  15  can be prevented from falling out of the terminal-housing grooves  132 . 
     Thus, through the descriptions, the forward/backward rotation switching mechanism of the present invention has been completely introduced and disclosed; in summary, the present invention has the following advantages:
     1. In this forward/backward rotation switching mechanism, for preventing the first contact terminal  14  and the second contact terminal  15  from falling out of the terminal-housing grooves  132 , each of the terminal-housing grooves  132  are provided with two terminal-locking portions  1321  and two first locking portions  141  and two second locking portions  151  are formed on the first contact terminal  14  and the second contact terminal  15 , respectively; therefore, after the first contact terminal  14  and the second contact terminal  15  are assembled into the terminal-housing grooves  132 , their locking portions  141 ,  151  would lock the terminal-locking portions  1321 , such that the first contact terminal  14  and the second contact terminal  15  can be prevented from falling out of the terminal-housing grooves  132 .   2. In addition, in order to avoid this forward/backward rotation switching mechanism from getting the external dust into the interior thereof, the turntable  12  is provided with a plurality of dust-off trenches  123 ; therefore, even if the forward/backward rotation switching mechanism  1  of the present invention is used in an environment having a lot of dust, the turntable  12  can still be turned around because the dust is ruled out by the dust-off trenches  123 .   3. Inheriting to above point  2 , moreover, in this forward/backward rotation switching mechanism, the circuitous embedding opening  114  on the turntable-corresponding recess  111  has circuitous portions  1141  for lengthening the invasion path of the dust, such that the invading dust located between the turntable  12  and the cover  11  can be extremely effectively reduced.   4. Furthermore, moreover, in this forward/backward rotation switching mechanism, because the turntable  12 , the first contact terminal  14  and the second contact terminal  15  are assembled with the terminal-fixing body  13 , and the terminal fixing body  13  is fixed in the cover  11  through the fixing ball  16  and the return spring  17 ; thus, when the turn handle  121  is forced to make the turntable  12  rotate forwardly, the motor is switched and makes a forward rotation, meanwhile, unless forcing the turn handle  121  to make the turntable  12  rotate backwardly, the rotation way of the motor would not be influenced even if the switch device  2  is subject to push or vibration made by external forces.   

     The above description is made on embodiments of the present invention. However, the embodiments are not intended to limit scope of the present invention, and all equivalent implementations or alterations within the spirit of the present invention still fall within the scope of the present invention.