Patent Publication Number: US-2016233036-A1

Title: Switch device

Description:
TECHNICAL FIELD 
     The present invention relates to a switch device that performs electrical connection and disconnection between switch contacts by pressing an operating body, and the switch device includes a lock mechanism for locking the operating body at a predetermined travel position. 
     BACKGROUND ART 
     In recent years, an input device including a rotary type input device and a push-push type switch device combined together is used for operating electronic devices, such as an air-conditioner, audio device in a vehicle. This input device is mounted to a front panel or around a console box of the vehicle. The input device is required to have a small size and assure users of fail-free operation. 
       FIG. 9  is an exploded perspective view of rotary input device  2  including conventional switch device  3 . Rotary input device  2  includes rotary operating section  2 A that is rotatable. Rotary input device  2  is disposed such that rotary operating section  2 A protrudes from opening  1 A of front panel  1 , and switch device  3  is disposed under rotary input device  2 . Rotary input device  2  and switch device  3  are connected to an air-conditioner in the vehicle. 
     Switch device  3  is disclosed in, for instance, PTL 1. 
     At the center of rotary input device  2 , push button  2 B movable in upward and downward directions is placed, and a pressing section laterally extending from the lower part of push button  2 B presses operating body  3 A of switch device  3 . 
     An operation of rotary input device  2  will be described below. Upon push button  2 B being pressed, operating body  3 A moves in the in the upward and downward directions to perform electrical connection and disconnection between switch contacts provided in housing  3 B of switch device  3 . At this moment, a stopper urged by a plate spring is engaged with a cam section having a heart shape provided on a side surface of operating body  3 A disposed inside housing  3 B, thereby retaining switch device  3  at a predetermined travel position, in other words, locking switch device  3  in a locked state. A ventilating of the interior of the vehicle by inside air circulation is thus selected from an outside air introduction and an inside air circulation. 
     Upon push button  2 B being pressed while switch device  3  is locked, the engagement between the cam section and the stopper is released, so that operating body  3 A may be urged by a coil spring disposed below operating body  3 A, is restored to an upward position, and falls into a release state. At this moment, electrical connection and disconnection between the switch contacts is performed, thereby the ventilation is restored to the outside air introduction originally set. 
     A clockwise turn of rotary operating section  2 A of rotary input device  2  to position  4 , which refers to a defrosting mode of a windshield of the vehicle, allows a lateral pressing section protruding outside from a lower surface of rotary operating section  2 A to push backward the releaser  3 C protruding from a side surface of switch device  3 . 
     Upon being pushed, releaser  3 C releases the engagement between an inner stopper and the cam section for restoring operating section  3 A, which has been urged upward, to an original release position. At this moment, electrical connection and disconnection between the switch contacts is performed, so that the ventilation method by the outside air introduction may be selected in the air-conditioner, and dry air is blown to an inner side of the windshield. 
     In other words, a shift of operating body  3 A of switch device  3  in the in the upward and downward directions allows the operating body  3 A to be locked or released, and at this moment, electrical connection and disconnection between the switch contacts is performed. On the other hand, a press on a side surface of releaser  3 C, protruding from the side surface of housing  3 B with operating body  3 A being locked, allows releaser  3 C to release the engagement between the stopper and the cam section, thereby allowing operating section  3 A to be restored to the release position. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Patent Laid-Open Publication No. 2000-331563 
     SUMMARY 
     A switch device includes a housing, an operating body accommodated movably in the housing, a stopper to lock the operating body, a switch contact performing electrical connection and disconnection in response to the movement of the operating body, a releaser disposed in the housing, and a retainer spring disposed in the housing. The operating body includes a cam section. The stopper includes an engaging section which is engaged with the cam section upon a movement of the operating body as to lock the operating body. The releaser includes a working section projecting outward from the housing. The retainer spring urges the releaser in a predetermined direction. When the operating body is locked, one of the releaser and the retainer spring presses the stopper to engage the engaging section with the cam section and retain the engaging section at the cam section. While the engaging section is engaged with the cam section and retained with the cam section, an operation on the working section of the releaser causes the releaser to move, and causes one of the releaser and the retainer spring to move in a direction away from the stopper as to disengage the engaging section from the cam section. 
     The switch device includes a small number of components with a simpler structure, and has a small size. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a sectional view of a switch device in accordance with Exemplary Embodiment 1. 
         FIG. 2  is an exploded perspective view of the switch device in accordance with Embodiment 1. 
         FIG. 3  is an enlarged plan view of a cam section of the switch device in accordance with Embodiment 1. 
         FIG. 4A  is a sectional view of the switch device in accordance with Embodiment 1 for illustrating an operation of the switch device. 
         FIG. 4B  is a sectional view of the switch device in accordance with Embodiment 1 for illustrating the operation of the switch device. 
         FIG. 4C  is a sectional view of the switch device in accordance with Embodiment 1 for illustrating the operation of the switch device. 
         FIG. 5  is a perspective view of an input device including the switch device in accordance with Embodiment 1. 
         FIG. 6  is a sectional view of a switch device in accordance with Exemplary Embodiment 2. 
         FIG. 7  is an exploded perspective view of the switch device in accordance with Embodiment 2. 
         FIG. 8A  is a sectional view illustrating actions of the switch device in accordance with the second embodiment. 
         FIG. 8B  is a sectional view of the switch device in accordance with Embodiment 2 for illustrating an operation of the switch device. 
         FIG. 8C  is a sectional view of the switch device in accordance with Embodiment 2 for illustrating the operation of the switch device. 
         FIG. 9  is an exploded perspective view of an input device including a conventional switch device. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Exemplary Embodiment 1 
       FIG. 1  and  FIG. 2  are a sectional view and an exploded perspective view of switch device  30  in accordance with Exemplary Embodiment 1, respectively. Housing  11  having a box shape having an opening that opens in upward direction  101 , and is made of insulating resin, such as polybutylene terephthalate (PBT). 
     Plural fixed contacts  112 A,  112 B, and  112 C are made of conductive metal plates, such as copper alloy plate. These fixed contacts are insert-molded with insulating resin, such as PBT, to form fixed contact assembly  13 . Fixed contacts  112 A,  112 B, and  112 C are arranged in upward direction  101  in this order. Fixed contact assembly  13  is placed in forward direction  103  in housing  11  while fixed contact assembly  13  is placed in backward direction  104  in housing  11 . Forward direction  103  and backward direction  104  are perpendicular to upward direction  101  (downward direction  102 ). Terminal sections  12 A,  12 B, and  12 C are disposed on lower parts of fixed contacts  112 A,  112 B, and  112 C, respectively, and protrude from a lower surface of housing  11  in downward direction  102 . Two fixed contact assemblies  13  faces in forward direction  103  (backward direction  104 ). Two fixed contacts  112 A (terminal section  12 A) face each other in forward direction  103  (backward direction  104 ). Two fixed contacts  112 B (terminal section  12 A) face each other in forward direction  103  (backward direction  104 ). Two fixed contacts  112 C (terminal section  12 A) face each other in forward direction  103  (backward direction  104 ). 
     Operating body  14  is made of insulating resin, such as PBT or polyoxymethylene (POM). Operating body  14  includes base section  14 A and operating section  14 B provided on base section  14 A. Operating body  14  is accommodated movably in upward direction  101  and downward direction  102  within housing  11  such that operating section  14 B protrudes from opening  11 A in upward direction  101 . 
     Cam section  15  is provided on a side surface of operating section  14  in leftward direction  105  perpendicular to upward direction  101  (downward direction  102 ) and forward direction  103  (backward direction  104 ). Cam section  15  includes protrusion cam  15 A having a heart shape, and groove  15 B formed around protrusion cam  15 A and having a groove shape. Plural steps are sequentially formed in groove  15 B, and cam section  15  forms a heart-shaped cam. 
     Compartments  14 C are provided in respective side surfaces of base section  14 A of operating body  14  in forward direction  103  and backward direction  104 . Each of compartments  14 C accommodates therein movable contact  16  having a clip shape and made of conductive metal plate, such as phosphor bronze plate. Movable contact  16  nips fixed contacts  112 A,  112 B, and  112 C and elastically contacts fixed contacts  112 A,  112 B, and  112 C. To be more specific, movable contact  16  nips two fixed contacts out of the three contacts simultaneously and elastically contact the two contacts. Movable contact  16  thus elastically contacts not all the three fixed contacts simultaneously. Movable contact  16  switches switch contact  16 A between a first connection state in which movable contact  16  connects fixed contact  112 A to fixed contact  112 B (connect terminal section  12 A to terminal section  12 B), and disconnects fixed contact  112 C (terminal section  12 C) from fixed contacts  112 B,  112 C (terminal sections  12 B,  12 C) and a second connection state in which movable contact  16  connects fixed contacts  112 B to fixed contact  112 C (connect terminal section  12 B to terminal section  12 C) and disconnects fixed contact  112 A (terminal section  12 A) from fixed contacts  112 B,  112 C (terminal sections  12 B,  12 C). 
     Movable contact  16  and fixed contacts  112 A to  112 C constitute switch contact  16 A such that a movement of operating body  14  in upward direction  101  and downward direction  102  causes movable contact  16  to move in upward direction  101  and downward direction  102 , thereby performing connection and disconnection between movable contact and fixed contacts  112 A to  112 C. 
     Stopper  17  is made of metal wire, such as a stainless wire or a piano wire. Stopper  17  includes engaging section  17 A formed at the upper part thereof, supporting section  17 B formed at the lower part thereof, and linear section  17 C extending from engaging section  17 A substantially in downward direction  102  to supporting section  17 B. Engaging section  17 A has substantially an L-shape bent from linear section  17 C towards cam section  15  in rightward direction  106  opposite to leftward direction  105 . Supporting section  17 B has substantially an L-shape bent from linear section  17 C in leftward direction  105  opposite to engaging section  17 A. 
     Supporting section  17 B of stopper  17  contacts an upper surface of small projection  11 B on a bottom surface of housing  11  while engaging section  17 A contacts groove  15 B formed in the lower part of cam section  15 . 
     Coil spring  18  is mounted between a lower surface of operating body  14  and the bottom surface of housing  11 , and slightly compressed to urge operating body  14  upward. Stopper  17  extends through the inside of coil spring  18 , and a lower end of coil spring  18  elastically urges supporting section  17 B of stopper  17  from above to urge stopper  17  in downward direction  102  with respect to small projection  11 B as a fulcrum, thereby urging engaging section  17 A, i.e. an upper end of stopper  17  toward cam section  15  even with a small force. 
     Retainer spring  19  has substantially a rectangular shape and is made of elastic metal plate, such as stainless plate or copper-alloy plate. Retainer spring  19  includes fixing section  19 A formed at the lower end thereof, and retaining section  19 B formed at the upper end thereof. Fixing section  19 A is held with supporting wall  11 C that protrudes from the bottom surface of housing  11  near an inner wall of housing  11  in leftward direction  105 . Retaining section  19 B is bent to have an L-shape and contacts a side surface of engaging section  17 A of stopper  17  in leftward direction  105 , or disposed near the side surface of engaging section  17 A of stopper  17  with a space between retaining section  19 B and the side surface. 
     Releaser  20  has substantially a rectangular frame shape and is made of insulating resin, such as PBT or POM. Cover  21  opens in downward direction  102 , and is made of insulating resin, such as PBT or POM. Releaser  20  is disposed between an upper surface of housing  11  and cover  21  such that releaser  20  surrounds an outer circumference of operating body  14 . Releaser  20  is mounted to operating body  14  such that releaser  20  can move in leftward direction  105  and rightward direction  106  of operating body  14 . 
     To be more specific, working section  20 A formed on the right side of releaser  20  projects to an outside of housing  11  in rightward direction  106 . Working section  20 A includes slidable sections  20 B at both insides in forward direction  103  and backward direction  104 . Slidable sections  20 B can slide in apertures  21 A in cover  21  along leftward direction  105  and rightward direction  106 . 
     Frame section  20 C extends from slidable sections  20 B into housing  11  and includes releasing section  20 D formed inside the frame section  20 C. Retaining section  19 B of retainer spring  19  which is slightly compressed elastically contacts releasing section  20 D, thereby urging releaser  20  in rightward direction  106 . 
     When slidable section  20 B slides in aperture  21 A, a bridge between slidable section  20 B and working section  20 A on right side, and a bridge between slidable section  20 B and frame section  20 C on left side cover a space of aperture  21 A, hence providing no opening This structure allows switch device  30  to keep off dust even if switch device  30  is used in a vehicle at dusty environment to stably perform electric connection and disconnection of switch contact  16 A. 
     Cover  21  is disposed above releaser  20  in upward direction  101  and has plural engaging holes  21 B provided in both side surfaces of cover  21  in leftward direction  105  and rightward direction  106 . Engaging holes  21 B face engaging sections  11   d  formed on housing  11  at both side surfaces. Engaging sections  11 D of housing  11  engage with engaging holes  21 B of cover  21  while cover  21  is mounted to housing  11 . 
     Cover  21  includes restraint section  21 C projecting from cover  21  at the left side lower end thereof. Restraint section  21 C is disposed inside housing  11  such that restraint section  21 C restrains supporting section  17 B of stopper  17  from moving upward. Cover  21  covers opening  11 A in the upper surface of housing  11 . Switch device  30  is thus constructed. 
     An operation of switch device  30  will be described below.  FIG. 3  is an enlarged plan view of cam section  15 .  FIGS. 4A to 4C  are sectional views of the switch device in accordance with Embodiment 1 for illustrating the operation. As shown in  FIG. 1 , when switch device  30  stays in a release state where operating body  14  protrudes from the upper surface of cover  21  to the most highest position, engaging section  17 A of stopper  17  is located at position P 1  in groove  15 B below protrusion cam  15 A as shown in  FIG. 3 . 
     Upon having operating section  14 B pressed in downward direction  102 , operating body  14  moves in downward direction  102  while compressing coil spring  18 . 
     The movement of operating body  14  in downward direction  102  shifts switch contact  16 A from the first connection state to the second connection state. To be more specific, in the first connection state, movable contact  16  elastically contacts fixed contacts  112 A and  112 B located above movable contact  16 , so that switch contact  16 A can be connected to terminal sections  12 B and  12 C. In the second connection state, movable contact  16  elastically contacts fixed contacts  112 B and  112 C located below movable contact  16 , so that movable contact  16  causes terminal sections  12 A and  12 B to be connected with switch contact  16 A. 
     At this moment, as shown in  FIG. 3 , the movement of operating body  14  in downward direction  102  causes engaging section  17 A of stopper  17  to slide on the steps formed in groove  15 B anticlockwise to position P 2  where engaging section  17 A engages with the upper surface of protrusion cam  15 A, so that operating body  14  can be retained and locked at a predetermined position and locked. 
     In this locked state, coil spring  18  urges engaging section  17 A of stopper  17  toward cam section  15  with a smaller force while coil spring  18  urges operating body  14  in upward direction  101  with a larger force. This mechanism applies a strong force to engaging section  17 A as to cause engaging section  17 A to slip out from the upper surface of protrusion cam  15 A toward leftward direction  105 . However, retainer spring  19  contacts or elastically contacts a side surface of engaging section  17 A on leftward direction  105  side to keep the engagement between engaging section  17 A and the upper surface of protrusion cam  15 A, so that engaging section  17 A may be engaged with cam section  15  without fail and the locked state is maintained. 
     Next, upon having operating section  14 B pressed again, operating body  14  moves to the lowest position, i.e. full-stroke position, and engaging section  17 A slides anticlockwise to position P 3  from position P 2  which is located at the upper part of protrusion cam  15 A, thereby releasing the engagement of engaging section  17 A with protrusion cam  15 A, and unlocking operating body  14 . 
     Then, operating body  14  is urged in upward direction  101  and is restored to the original release position shown in  FIG. 1 , and engaging section  17 A is restored to position P 1  shown in  FIG. 3 , so that switch contact  16 A falls in the first connection state. 
     When switch device  30  stays in the locked state as shown in  FIG. 4A , working section  20 A, of releaser  20  protruding from the right side of switch device  30  is pushed in leftward direction  105 , then releasing section  20 D slides in leftward direction  105  while releasing section  20 D pushes retaining section  19 B of retainer spring  19  in leftward direction  105 , as shown in  FIG. 4B . 
     At this moment, as shown in  FIG. 4C , retainer spring  19  pushed by releasing section  20 D elastically deforms in leftward direction  105 , and retaining section  19 B is removed from engaging section  17 A of stopper  17 , thus releasing the engagement of engaging section  17 A with protrusion cam  15 A. As a result, operating body  14  is unlocked, and urged by coil spring  18  to be restored to the release position. 
     Then, the pushing of working section  20 A is released, releaser  20  urged rightward by retainer spring  19  slides in rightward direction  106 . Releaser  20  is thus restored to an original position and protrudes to an outside of housing  11  in rightward direction  106 . 
     As discussed above, switch device  30  is locked and unlocked by moving operating body  14  in upward direction  101  and downward direction  102  while performing the electric connection and disconnection to switch contact  16 A. Working section  20 A of releaser  20  protruding outward from the side surface of housing  11  in the locked state is pushed toward housing  11  to cause releaser  20  to slide. This operation allows releasing section  20 D of releaser  20  to cause retainer spring  19  to deform elastically in leftward direction  105  opposite to the direction toward cam section  15 . Retaining section  19 B is thus removed from engaging section  17 A of stopper  17 , and releases the engagement of engaging section  17 A with cam section  15 , thereby unlocking operating body  14 . 
       FIG. 5  is an exploded perspective view of input device  32  including switch device  30 . Input device  32  is mounted to a vehicle, and includes rotary operating section  32 A. Input device  32  is disposed such that operating section  32 A protrudes from opening  31 A of front panel  31  in the vehicle. Switch device  30  is disposed below input device  32 . Switch device  30  is mounted to wiring board  33  by soldering terminal section  12 A to wiring board  33 . 
     Push button  32 B is mounted to the center of input device  32  while the push button is movable in upward and downward directions. Switch device  30  is placed such that operating section  14 B extending outside can be pushed with push button  32 B. 
     Input device  32  and switch device  30  are connected to, for instance, an electric circuit of the vehicle via wiring board  33  disposed below input device  32  and switch device  30 , thus providing an input device for operating an air-conditioner. 
     Upon being pushed, push button  32 B presses operating section  14 B via a pushing section at the lower part of push button  32 B, and a movement of operating body  14  in downward direction  102  brings switch contact  16 A from the first connection state into the second connection state. A signal indicating the second connection state is transmitted to the electric circuit of the vehicle, and the signal selects air circulation from modes for air-intake in the interior of the vehicle, namely, an outside air introduction, and an inside air circulation. Then, the air of the interior is circulated. 
     At this moment, operating body  14  is retained at a predetermined position by the engagement of stopper  14  with cam section  15 , and falls in a locked state. 
     Next, upon having push button  32 B pushed again in the locked state, push button  32 B releases the engagement of stopper  17  with cam section  15 , thereby unlocking operating body  14  and being restored to the release position. This mechanism brings switch contact  16 A into the first connection state from the second connection state, so that the air-conditioner, for instance, turns to the outside air introduction mode. 
     When switch device  30  is in the locked state and the air-conditioner stays in the inside air circulation mode, the windshield tends to invite fogginess thereon. In this case, rotary operating section  32 A of input device  32  is rotated to, e.g. a predetermined position indicated by “4” that refers to a defrosting mode. 
     At this moment, upon being rotated to the predetermined position, rotary operating section  32 A causes a side pushing section projecting outward in downward direction  102  from the lower part of operating section  32 A to push working section  20 A of releaser  20  projecting in rightward direction  106  from switch device  30 . 
     Upon having working section  20 A pushed, releaser  20  slides in leftward direction  105 , allowing operating body  14  to be unlocked and restored to the release position. The air-conditioner thus turns to the outside air introduction mode. At this moment, input device  32  transmits a predetermined signal corresponding to the first connection state, thereby allowing the outside air to be blown from a blow-off port disposed below the windshield to remove the fogginess. 
     In switch device  30  in accordance with Embodiment 1, retainer spring  19  elastically contacts releasing section  20 D of releaser  20  to urge releaser  20  outward. While operating body  14  is in the locked state, the pushing of working section  20 A causes releaser  20  to deform retainer spring  19  elastically to remove retainer spring  19  from stopper  17 . This operation releases the engagement of stopper  17  with cam section  15 , and unlocks operating body  14 . Since retainer spring  19  keeps the locked state and urges releaser  20  outward, it is not necessary to prepare another urging device to urge releaser  20 . Switch device  30  has a small size with a small number of components with a simpler structure. This switch device  30  allows operating body  14  to be locked or unlocked without fail, and releaser  20  to perform releasing the locked state without fail. 
     In a conventional switch device  3  shown in  FIG. 9 , a part of the cam section having a heart shape is formed at the end section of the releaser within the housing, and the stopper is urged by a plate spring to the cam section so that the stopper rolls on a surface of the cam section, or engages with the cam section to be retained there. The pushing of the releaser in a predetermined direction causes the part of the cam section, namely, the end section of the releaser, to push the stopper outward, thereby releasing the engagement of the stopper with the cam section. At this moment, an urging spring disposed between the releaser and an operating body urges the releaser outward. This structure involves a large number of components and invites a complicated structure, hence preventing conventional switch device  3  from having a small size. 
     In the conventional switch device  3 , the releaser is mounted to the operating body and extends through the substantially intermediate part of the operating body, and can move in directions perpendicular to the in the upward and downward directions. The releaser moves in the upward and downward directions following the movement of the operating body in the upward and downward directions, so that an opening extending in the upward and downward directions is formed on a side surface of the housing to define a movable range of the releaser. This opening tends to allow dust to enter. In the case that switch device  3  has a dust-proof structure, a cover for shielding the opening is needed, and yet a driving body for pressing the releaser is needed, so that switch device  3  becomes bulky and complicate. 
     In switch device  30 , releaser  20  has substantially a rectangular frame shape and is movable by sliding in leftward direction  105  and rightward direction  106 , i.e. a direction substantially perpendicular to upward direction  101  and downward direction  102  along which operating body  14  moves. This arrangement allows operating body  14  to be placed inside the frame of releaser  20  such that operating body  14  is movable in the upward and downward directions, and allows releaser  20  to be strong enough as a pressing member. This structure stabilizes the operation of releaser  20 , and provides switch device  30  with a small size and error-free operation. 
     Exemplary Embodiment 2 
       FIG. 6  and  FIG. 7  are a sectional view and a perspective exploded view of switch device  50  in accordance with Exemplary Embodiment 2, respectively. In  FIG. 6  and  FIG. 7 , components identical to those of switch device  30  shown in  FIGS. 1-3  in accordance with Embodiment 1 are denoted by the same reference numerals. Housing  41  has a box shape having an opening that opens in upward direction  101 , and made of insulating resin. A side surface in leftward direction  105  of housing  41  has cut-out section  41 A provided therein. 
     Plural fixed contacts  142 A,  142 B, and  142 C are made of conductive metal plate, such as copper alloy, and are insert-molded with insulating resin, such as PBT, thereby forming fixed contact assembly  43 . Fixed contacts  142 A,  142 B, and  142 C are arranged in this order in upward direction  101 . Fixed contact assemblies  43  are fixed inside housing  11  in forward direction  103  and backward direction  104  perpendicular to upward direction  101  (downward direction  102 ), respectively. Fixed contacts  142 A,  142 B, and  142 C include terminal sections  42 A,  42 B, and  42 C at their lower sections thereof, respectively. Two fixed contact assemblies  43  face each other in forward direction  103  (backward direction  104 ). Terminal sections  42 A,  42 B, and  42 C protrude from a lower surface of housing  11  in forward direction  103 , and terminal sections  42 A,  42 B, and  42 C protrude from the lower surface of housing  11  in backward direction  104 . The terminal sections extend substantially in parallel with the lower surface of housing  11 . Two fixed contacts  142 A (two terminal sections  42 A) face each other in forward direction  103  (backward direction  104 ). Two fixed contacts  142 B (two terminal sections  42 B) face each other in forward direction  103  (backward direction  104 ). Two fixed contacts  142 C (two terminal sections  42 C) face each other in forward direction  103  (backward direction  104 ). 
       FIG. 7  shows terminal sections  42 A,  42 B, and  42 C originally extend linearly downward before the terminal sections are inserted into housing  41 , and then are bent, as shown in  FIG. 7 . 
     Similarly to switch device  30  in accordance with Embodiment 1, switch device  50  in accordance with Embodiment 2 includes operating body  14  having cam section  15  provided to a side surface in leftward direction  105  of operating body  14 . Operating body  14  includes compartment  14 C accommodating movable contact  16  therein. Operating body  14  is urged by coil spring  18  in upward direction  101 , and accommodated in housing  41  such that operating body  14  can move in upward direction  101  and downward direction  102 . Upon moving in the upward and downward directions, operating body  14  establishes electrical connection and disconnection of switch contact  16 A including movable contact  16  and fixed contacts  142 A to  142 C. 
     Similarly to switch device  30  in accordance with Embodiment 1, switch device  50  in accordance with Embodiment 2 includes stopper  17  that contacts small projection  41 B formed on a bottom surface of housing  41 , and engaging section  17 A contacts groove  15 B formed below cam section  15 . 
     Releaser  44  has an inverted L-shape, and made of insulating resin, such as PBT and POM. Releaser  44  includes working section  44 A protruding outside and downward from cutout section  41 A of housing  41 , and retaining section  44 B extending inside housing  41 . 
     Releaser  44  includes shaft  44 C provided substantially at the center thereof. Shaft  44 C protrudes both in forward direction  103  and backward direction  104 , and is supported rotatably by recessed shaft supporter  41 C formed inside housing  11  to receive shaft  44 C. 
     The distance from shaft  44 C to an end of working section  44 A is longer than the distance from shaft  44 C to an end of retaining section  44 B. 
     Retainer spring  45  has an inverted V-shape that opens in downward direction  102  in a side view from forward direction  103  (backward direction  104 ), and is made of an elastic metal plate, such as a stainless plate or a copper alloy plate. The retainer spring  45  having the inverted V-shape has bent section  45 A, side  45 B extending downward from bent section  45 A and disposed in rightward direction  106 , and side  45 C extending downward from bent section  45 A and disposed in leftward direction  105 . Side  45 B in rightward direction  106  of retainer spring  45  is engaged with a side wall of housing  41  in leftward direction  105  and fixed there. Bent section  45 A of retainer spring  45  is placed at cutout section  41 A of housing  41 . Side  45 C of retainer spring  45  in leftward direction  105  elastically contacts inside working section  44 A of releaser  44  while slightly compressing retainer spring  45 , so that retainer spring  45  can urge releaser  44  clockwise viewed in backward direction  104  from releaser  44 . 
     Cover  46  is made of insulating resin, and covers the opening in an upper surface of housing  41  and an upper surface of working section  44 A of releaser  44 . Cover  46  includes rotation supporting section  46 A at a lower surface thereof for covering an upper section of shaft  44 C. Cover  46  is mounted to housing  41 , providing switch device  50 . 
     An operation of switch device  50  will be described below.  FIGS. 8A to 8C  are sectional views of switch device  50  for illustrating the operation of switch device  50 . Similarly to switch device  30  in accordance with Embodiment 1, switch device  50  in accordance with Embodiment 2 includes operating body  14  having operating section  14 B. The pressing of operating section  14 B causes operating body  14  to move in the upward and downward directions, and operating body  14  is locked or unlocked by stopper  17  and cam section  15 . At this moment, electric connection and disconnection is performed to switch contact  16 A. 
     Switch device  50  is different from switch device  30  in a method of releasing the locked state by releaser  44 .  FIGS. 8A to 8C  are sectional views of switch device  50  for illustrating the operation of switch device  50 . 
     As shown  FIG. 8A , engaging section  17 A of stopper  17  is pushed by retaining section  44 B of releaser  44 , and allows engaging section  17 A to be engaged with the upper surface of protrusion cam  15 A and is retained there, thereby locking switch device  50 . 
     In this locked state, since the distance from shaft  44 C to the end of retaining section  44 B is shorter than the distance from shaft  44 C to the end of working section  44 A, retaining section  44 B pushes stopper  17  with a strong and proper force that is produced inversely proportional to the distance from shaft  44 C although the urging force applied from retainer spring  45  to working section  44 A is rather small. 
     In this locked state, working section  44 A of releaser  44  is pushed toward housing  41  anticlockwise viewed from backward direction  104  of releaser  44 , and then, as shown  FIG. 8B , releaser  44  resists to the urging force of retainer spring  45  and rotates anticlockwise about shaft  44 C viewed from backward direction  104  of releaser  44 . At this moment, the rotation of releaser  44  causes retaining section  44 B to rotate to remove releaser  44  from engaging section  17 A of stopper  17 , so that engaging section  17 A leaves protrusion cam  15 A, thereby unlocking switch device  50 . As a result, as shown in  FIG. 8C , operating body  14  is urged by coil spring  18  and restored to the release position. 
     An input device including switch device  50  has a structure similar to the input device according to Embodiment 1 shown in  FIG. 5 . However, working section  44 A of releaser  44  in switch device  50  protrudes outside housing  41  in downward direction  102 , so that the lateral pushing section projecting from the lower part of rotary operating section  32 A is configured to press around the upper surface of wiring board  33  disposed below housing  41  of switch device  50 . 
     In switch device  50 , the distance from shaft  44 C to the end of retaining section  44 B is shorter than the distance from shaft  44 C of releaser  44  to the end of working section  44 A. This structure allows retaining section  44 B to push stopper  17  with large and proper force that is produced inversely proportional to the distance from shaft  44 C, although retainer spring  45  urges working section  44 A with rather smaller force. As a result, load for pressing the releaser  44  can be rather smaller. This load is produced by rotating rotary operating section  32 A, and is transmitted via the lateral pushing section to press the releaser  44 . 
     As discussed above, in switch device  50  in accordance with Embodiment 2, when operating body  14  is locked, retaining section  44 B of releaser  44  pushes stopper  17  with the urging force of retainer spring  45 , so that stopper  17  is engaged with cam section  15  and is retained there. Then, the pushing of working section  44 A of releaser  44  removes retaining section  44 B from stopper  17 , thereby releasing the engagement of stopper  17  with cam section  15 . As a result, operating body  14  is unlocked. This mechanism allows releaser  44  that is urged by retainer spring  45  maintains the locked state, and working section  44 A of releaser  44  is urged outward, so that there is no need to prepare another urging device for urging releaser  44  outward. Switch device  50  has a small size with a simple structure and a smaller number of components. Switch device  50  allows operating body  14  to lock and unlock switch device  50  without fail, or allows releaser  44  to unlock switch device  50  without fail. 
     Switch device  30  in accordance with Embodiment 1 includes terminal sections  12 A,  12 B, and  12 C extending linearly from the lower surface of housing  11 , and these terminal sections extend through through-holes of wiring board  33  disposed below housing  11 , and the terminal sections are dip-soldered. Terminal sections  42 A,  42 B, and  42 C of switch device  50  in accordance with Embodiment 2 are bent substantially in parallel to the lower surface of housing  41 , and mounted onto land patterns formed on wiring board  33  by reflow-soldering. Switch device  30  in accordance with Embodiment 1 may include terminal sections  12 A,  12 B, and  12 C having the same shapes as terminal sections  42 A,  42 B, and  42 C of switch device  50  in accordance with Embodiment 2. To the contrary, terminal sections  42 A,  42 B, and  42 C of switch device  50  in accordance with Embodiment  2  may have the same shape as terminal sections  12 A,  12 B, and  12 C of switch device  30  in accordance with Embodiment 1. Terminal sections  12 A to  12 C of switch device  30  and terminal sections  42 A to  42 C of switch device  50  may have other shapes. 
     In switch devices  30  and  50  in accordance with Embodiments 1 and 2, switch contact  16 A includes movable contact  16  having a clip shape and fixed contacts  112 A to  112 C and  142 A to  142 C having plate shapes. The switch contact may include fixed contacts having plate shape and a movable contact having a brush shape that faces, and elastically contacts the fixed contacts, and slides on the fixed contacts. The switch contact may include a movable contact having a dome shape and fixed contacts having plate shapes facing the movable contact having the dome shape. 
     In the embodiments previously discussed, terms, such as “upper surface”, “lower surface”, “upward direction”, “downward direction”, “forward direction”, “backward direction”, “rightward direction”, and “leftward direction”, indicating directions merely indicate relative directions depending on only relative positional relations of structural elements of switch devices  30  and  50 , and do not indicate absolute directions, such as a vertical direction. 
     INDUSTRIAL APPLICABILITY 
     A switch device according to the present invention includes a small number of components with a simple structure, hence having a small size. This switch device allows its operating body to lock or unlock the switch device or the releaser to unlock the switch device without fail. The switch device is useful for operating various electronic devices installed mainly in vehicles. 
     REFERENCE MARKS IN THE DRAWINGS 
     
         
           11 ,  41  housing 
           11 D engaging section 
           14  operating body 
           14 B operating section 
           15  cam section 
           16 A switch contact 
           17  stopper 
           17 A engaging section 
           17 B supporting section 
           19 ,  45  retainer spring 
           20 ,  44  releaser 
           20 A,  44 A working section 
           21 ,  46  cover 
           30 ,  50  switch device 
           32  input device