Patent Publication Number: US-11024476-B2

Title: Push-button switch

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is the U.S. national stage of application No. PCT/JP2018/044229, filed on Nov. 30, 2018. Priority under 35 U.S.C. § 119(a) and 35 U.S.C. § 365(b) is claimed from Japanese Application No. 2017-254316 filed Dec. 28, 2017, the disclosure of which is also incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a push-button switch provided with a lock lever unit. 
     BACKGROUND ART 
     Patent document 1 discloses an operation switch including a contact portion having a contact B, an operation unit for opening and closing the contact B of the contact portion, and a lock mechanism having a lock lever capable of fixing the operation unit and the contact portion to each other. The lock lever is provided with a cam that rotates in conjunction with the rotation operation of the lock lever and is configured so that the contact B of the contact portion can be opened and closed. 
     In the operation switch, it is configured such that the lock lever is moved to the fully locked position in a state where one end of the operation unit is fitted into the mounting hole provided in the contact portion, and thereby the operation unit is fixed to the contact portion, and the contact B is switched from the off state to the on state at the same time. 
     RELATED ART DOCUMENTS 
     Patent Documents 
     Patent document 1: Japanese Patent No. 4147049 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the operation switch, when the operation unit is mounted to the contact portion, for example, in a state of being inclined with respect to the contact portion, or in a state in which one end of the operation unit is sufficiently inserted into the mounting hole of the contact portion, and the lock lever is operated, there is a case where such an incompletely mounted state of the operation unit cannot be determined from the outside, and the performance and safety of the operation switch cannot not be ensured. 
     An object of the present disclosure is to provide a push-button switch capable of reliably mounting an operation unit in a complete state. 
     Solution to Problem 
     A push-button switch according to an example of the present disclosure includes: 
     a housing having an operation surface provided with an operation hole and a housing portion provided therein and connected to the operation hole; 
     a plunger provided at an inside of the housing portion and movable between a return position away from the operation surface and an operating position in the middle between the operation surface and the return position along a movable direction intersecting the operation surface; 
     an operation unit that extends along the movable direction from an outside of the housing through the operation hole to the inside of the housing portion and is mounted to the housing in a state in which an end on the housing portion side in an extending direction is positioned at an initial position, and has a pressing surface provided at the outside of the housing and disposed so as to face the operation surface, in which the pressing surface is capable of an approaching operation with respect to the operation surface along the movable direction, and the end on the housing portion side moves from the initial position to a pressing position to position the plunger at the return position by the approaching operation; 
     a lock lever unit that has a lever body exposed to the outside of the housing and movable in a direction intersecting the movable direction between a first position and a second position, a lever support portion provided at the inside of the housing portion and connected to the lever body so as to be movable together with the lever body, and a holding unit capable of holding the lever body at the second position; 
     a transmission mechanism that is provided between the lock lever unit and the plunger inside the housing portion, moves the plunger from the return position to the operating position along the movable direction as the lever body moves from the first position toward the second position, but moves the plunger from the operating position to the return position along the movable direction as the lever body moves from the second position toward the first position; 
     a movement regulating portion that is provided between the operation unit and the lock lever unit inside the housing portion, and when the lever body is positioned at the first position, enables movement of the lever body to the second position when the end of the operation unit on the housing portion side is positioned at the initial position, but disables movement of the lever body to the second position when the end of the operation unit on the housing portion side is positioned closer to the operation surface than the initial position in the movable direction; 
     a contact mechanism that has a fixed contact portion provided at the inside of the housing portion and a movable contact portion that is provided at the inside of the housing portion so as to face the fixed contact portion, comes into contact with the fixed contact portion when the plunger moves from the return position to the operating position, and separates from the fixed contact portion when the plunger moves from the operating position to the return position; and 
     a first biasing portion provided at the inside of the housing portion and biasing the plunger from the operating position toward the return position along the movable direction. 
     Advantageous Effects of Invention 
     According to the push-button switch, it includes a lock lever unit having a lever body movable between a first position and a second position and a holding unit capable of holding the lever body at the second position, a transmission mechanism that moves a plunger from a return position to an operating position as the lever body moves from the first position toward the second position, and moves the plunger from the operating position to the return position as the lever body moves from the second position toward the first position, a movement regulating portion that, when the lever body is positioned at the first position, enables movement of the lever body to the second position when the end of the operation unit on the housing portion side is positioned at an initial position, but disables movement of the lever body to the second position when the end of the operation unit on the housing portion side is positioned closer to the operation surface than the initial position, and a first biasing portion that biases the plunger from the operating position toward the return position. That is, in the push-button switch, for example, when the operation unit once removed for maintenance or the like is attached to the housing, when the end of the operation unit on the housing portion side is positioned at the initial position, the lever body can be moved to the second position and held by the holding unit, while when the end of the operation unit on the housing portion side is positioned closer to the operation surface than the initial position in the movable direction, the lever body cannot be moved to the second position, and the lever body is biased by the first biasing portion via the plunger to move to the first position. This makes it possible to realize a push-button switch in which the operation unit can be reliably attached in a complete state. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a push-button switch according to an embodiment of the present disclosure. 
         FIG. 2  is a perspective view of the push-button switch of  FIG. 1  when viewed from a direction different from that of  FIG. 1 . 
         FIG. 3  is a front view of the push-button switch of  FIG. 1 . 
         FIG. 4  is a right-side view of the push-button switch in  FIG. 1 . 
         FIG. 5  is a left-side view of the push-button switch of  FIG. 1 . 
         FIG. 6  is a plan view of the push-button switch of  FIG. 1 . 
         FIG. 7  is a bottom view of the push-button switch of  FIG. 1 . 
         FIG. 8  is a sectional view taken along a line VIII-VIII in  FIG. 1 . 
         FIG. 9  is a front view of an operation unit of the push-button switch of  FIG. 1 . 
         FIG. 10  is a bottom view of the operation unit and a lock lever unit of the push-button switch of  FIG. 1 . 
         FIG. 11  is a perspective view showing an exterior portion of the push-button switch of  FIG. 1 . 
         FIG. 12  is a top view of a lever portion of the push-button switch of  FIG. 1 . 
         FIG. 13  is a perspective view of the push-button switch of  FIG. 1  with a part of housing and an operation unit made transparent. 
         FIG. 14  is a right-side view of the lever portion of the push-button switch of  FIG. 1 . 
         FIG. 15  is a perspective view of a plunger of the push-button switch of  FIG. 1 . 
         FIG. 16  is a perspective view of a first plunger of the push-button switch of  FIG. 1 . 
         FIG. 17  is a perspective view of a second plunger of the push-button switch of  FIG. 1 . 
         FIG. 18  is a perspective view of the lever portion and the plunger of the push-button switch of  FIG. 1 . 
         FIG. 19  is a first plan view for explaining the operation of a transmission mechanism of the push-button switch of  FIG. 1 , as viewed from an arrow A direction in  FIG. 18 . 
         FIG. 20  is a second plan view for explaining the operation of the transmission mechanism of the push-button switch of  FIG. 1 , as viewed from the arrow A direction in  FIG. 18 . 
         FIG. 21  is a perspective view showing a second plunger, a contact mechanism, and a terminal connection mechanism of the push-button switch of  FIG. 1 . 
         FIG. 22  is a first plan view for explaining the operation of the contact mechanism of the push-button switch of  FIG. 1 . 
         FIG. 23  is a second plan view for explaining the operation of the contact mechanism of the push-button switch of  FIG. 1 . 
         FIG. 24  is a sectional view taken along a line XXIV-XXIV in  FIG. 1 . 
         FIG. 25  is a first front view for explaining the operation of a lever body using a jig of the push-button switch of  FIG. 1 . 
         FIG. 26  is a second front view for explaining the operation of the lever body using the jig of the push-button switch of  FIG. 1 . 
         FIG. 27  is a view for explaining a first modification of a fulcrum projection of the push-button switch of  FIG. 1 . 
         FIG. 28  is a view for explaining a second modification of the fulcrum projection of the push-button switch of  FIG. 1 . 
         FIG. 29  is a view for explaining a third modification of the fulcrum projection of the push-button switch of  FIG. 1 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an example of the present disclosure will be described with reference to the accompanying drawings. In the following description, terms indicating a specific direction or position (for example, terms including “up”, “down”, “right”, “left”) will be used as necessary. However, they are used for facilitating understanding of the present disclosure with reference to the drawings, and the technical scope of the present disclosure is not limited by the meaning of those terms. It should be noted that the following description is merely exemplary in nature and is not intended to limit the present disclosure, its application, or its use. Furthermore, the drawings are schematic, and the ratios of the dimensions do not always match actual ones. 
     As shown in  FIGS. 1 to 7 , a push-button switch  1  according to an embodiment of the present disclosure includes a substantially cubic housing  10 , an operation unit  20  attached to the housing  10 , and a lock lever unit  30  provided so as to be exposed to an outside of the housing  10 . 
     The housing  10  has an operation surface  12  on which an operation hole  13  is provided. The operation hole  13  has, for example, a substantially circular shape. The operation unit  20  extends from the outside to the inside of the housing through the operation hole  13  in a movable direction (hereinafter, simply referred to as a movable direction) intersecting (for example, orthogonally) with the operation surface  12 , and one end thereof in the extending direction is positioned inside the housing  10  and is attached to the housing  10  in a movable state along the movable direction. Further, the lock lever unit  30  is disposed at an edge of the operation surface  12  of the housing  10 . 
     As shown in  FIG. 8 , a housing portion  11  connected to the operation hole  13  is provided inside the housing  10 . That is, one end of the operation unit  20  in the extending direction is disposed inside the housing portion  11 . Inside the housing portion  11 , a plunger  40  having a first plunger  41  and a second plunger  42 , a transmission mechanism  50  (shown in  FIGS. 19 and 20 ), a contact mechanism  60 , and a biasing portion  70  are provided. 
     The plunger  40  is disposed at an end of the housing portion  11  on the operation surface  12  side in the movable direction, and the biasing portion  70  is disposed at an end of the housing portion  11  on the terminal connection surface  14  side facing the operation surface  12  in the movable direction. In addition, the transmission mechanism  50  and the contact mechanism  60  are arranged between the plunger  40  and the biasing portion  70 . 
     Subsequently, each configuration of the push-button switch  1  will be described. 
     As shown in  FIGS. 1 and 2 , the housing  10  has the terminal connection surface  14  facing the operation surface  12  and four side surfaces extending in a direction intersecting the operation surface  12  and the terminal connection surface  14  (e.g., an orthogonal direction), and one of the four side surfaces constitutes a fulcrum forming surface  15 . 
     The fulcrum forming surface  15  is provided with a fulcrum projection  151  protruding from the fulcrum forming surface  15  toward the outside of the housing  10  in a direction intersecting with the fulcrum forming surface  15  (for example, an orthogonal direction). As shown in  FIG. 3 , the fulcrum projection  151  has an oval shape extending in a direction orthogonal to the movable direction when viewed from a direction orthogonal to the fulcrum forming surface  15  and is disposed in the middle between the operation surface  12  and the terminal connection surface  14  and at one side of the center of the fulcrum forming surface  15  in a direction orthogonal to the movable direction. 
     Specifically, the fulcrum projection  151  is, when viewed from a direction orthogonal to the fulcrum forming surface  15 , disposed closer to a first position P 1  than a center line CL (see  FIGS. 25 and 26 ) extending in the movable direction of the operation unit  20  passing through the center between the first position P 1  and a second position P 2  in a moving direction of the lever body  31 . 
     The fulcrum projection  151  is configured such that one curved surface  152  in an extending direction thereof, when the lever body  31  of the lock lever unit  30  described later is moved from the first position P 1  to the second position P 2  using a long jig  100  (see  FIGS. 25 and 26 ), comes into contact with an intermediate portion  102  of the jig  100  in which a distal end  101 , which is one end of the jig  100 , is locked to a locking portion  312  of the lock lever unit  30  described later, and serves as a rotation fulcrum of the jig  100 . That is, the curved surface  152  is provided at a portion that comes into contact with the intermediate portion  102  of the jig  100 , and protrudes from the fulcrum projection  151  toward the jig  100 . 
     As shown in  FIG. 7 , the terminal connection surface  14  is provided with a plurality of openings  141 . Each of the openings  141  is configured so that, for example, a conductor portion of an electric wire (not shown) can be inserted therein, and is connected to a terminal connection mechanism  16  provided inside the housing portion  11  as shown in  FIG. 8 . As an example, the terminal connection mechanism  16  employs a so-called push-in connection type, and is configured so that the conductor of the electric wire can be connected to the push-button switch  1  simply by inserting the conductor of the electric wire from the opening  141 . 
     As shown in  FIG. 1 , the operation unit  20  has a substantially cylindrical shape and has a pressing surface  21  provided outside the housing  10  and disposed so as to face the operation surface  12 . The operation unit  20  is configured to be able to perform an approaching operation in which the pressing surface  21  approaches the operation surface  12  along the movable direction, and is configured so that the plunger  40  is positioned at a later-described return position P 3  (see  FIG. 19 ) by this approaching operation. Specifically, when the plunger  40  is at the non-return position other than the return position P 3  (specifically, when the second plunger  42  is at a non-return position other than the return position P 32 ), an end  22  of the operation unit  20  on the housing portion  11  side moves from an initial position (shown in  FIG. 8 ) to a pressing position, and the operation unit  20  moves the plunger  40  along the movable direction to the return position P 3  (specifically, moves the second plunger  42  along the movable direction to the return position P 32 ). 
     As shown in  FIGS. 1 and 6 , the pressing surface  21  is provided with a display portion  25  that indicates the rotation direction of the operation unit  20  when the operation unit  20  is attached to the housing  10 . The display portion  25  is configured by a clockwise arrow when viewed from an approaching direction in which the pressing surface  21  approaches the operation surface  12  in the movable direction (hereinafter, simply referred to as an approaching direction). 
     As shown in  FIG. 9 , a first groove  23  extending in the movable direction and a second groove  24  connected to an end  231  of the first groove  23  on the pressing surface  21  side in the movable direction and extending in the circumferential direction of an end  22  of the operation unit  20  on the housing portion  11  side are provided on an outer circumferential surface of the end  22  of the operation unit  20  on the housing portion  11  side. The first groove  23  and the second groove  24  are configured to be capable of housing a locking projection  342  provided on the lock lever unit  30  described later. Further, when the lever body  31  is positioned at the first position P 1 , the first groove  23  is capable of housing the locking projection  342 , and the second groove  24  is, as shown in  FIG. 10 , configured to be capable of locking the locking projection  342  in the movable direction, when the lever body  31  is at the second position P 2 . 
     The locking projection  342  of the lock lever unit  30  and the first groove  23  and the second groove  24  of the operation unit  20  constitute a movement regulating portion  80 . When the lever body  31  is positioned at the first position P 1 , the movement regulating portion  80  enables movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position (that is, as shown in  FIG. 9 , a position of the end  22  of the operation unit  20  on the housing portion  11  side when the locking projection  342  is positioned at the end  231  of the first groove  23  on the pressing surface  21  side in the movable direction), but it disables movement by regulating movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position in the movable direction. When the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position, the first groove  23  and the second groove  24  are connected so that the operation unit  20  can be rotated only in one direction (in this embodiment, the arrow direction of the display portion  25 ). That is, the movement regulating portion  80  is provided between the operation unit  20  and the lock lever unit  30  inside the housing portion  11 , and can confirm whether or not the operation unit  20  has been securely attached to the housing  10  depending on whether or not the lever body  31  can be moved to the second position P 2 . 
     In addition, on the outer circumferential surface of the end  22  of the operation unit  20  on the housing portion  11  side, a display portion  25  (in this embodiment, an arrow in a direction from the pressing surface  21  toward the end  22  on the housing portion  11  side in the movable direction) indicating the mounting direction of the operation unit  20  to the housing  10  is provided. 
     As shown in  FIG. 1 , the lock lever unit  30  includes a lever portion  301  and an exterior portion  32  fixed to the housing  10  so as to cover the lever portion  301 . As shown in  FIG. 13 , the lever portion  301  has the lever body  31  exposed to the outside of the housing  10 , and a lever support portion  34  disposed in the housing portion  11 . 
     As shown in  FIG. 7 , the lever body  31  intersects (e.g., orthogonally) with the fulcrum forming surface  15  from the fulcrum forming surface  15  and protrudes in a direction away from the fulcrum forming surface  15 , and as shown in  FIG. 3 , is disposed between the pressing surface  21  and the operation surface  12  in the movable direction. When viewed from a direction orthogonal to the fulcrum forming surface  15 , the lever body  31  is configured to be movable in a direction (for example, the orthogonal direction) intersecting the movable direction between the first position P 1  (see  FIG. 24 ) and the second position P 2  (see  FIG. 25 ). 
     As shown in  FIGS. 6 and 7 , the exterior portion  32  includes a first wall portion  321  that faces an upper surface (that is, a surface on the opposite side in the movable direction of a facing surface  311  (shown only in  FIG. 7 ) facing the operation surface  12  of the lever body  31 ) in the movable direction of the lever body  31  and extends in the moving direction of the lever body  31 , and a second wall portion  322  and a third wall portion  323  respectively arranged on both sides of the lever body  31  in a direction orthogonal to the movable direction (that is, the moving direction of the lever body  31 ) and respectively connected to the first wall portion  321  and the operation surface  12  of the housing  10 . The moving range of the lever body  31  is defined by the exterior portion  32 . 
     As shown in  FIG. 6 , a holding unit  33  capable of holding the lever body  31  at the second position P 2  is provided at one end (that is, the right end in  FIG. 6 ) of the first wall portion  321  in the extending direction. Specifically, as shown in  FIG. 11 , the holding unit  33  has an elastic holding portion  331  capable of holding the lever body  31  by pressing the lever body  31  from one side to the other side (that is, from an upper side to a lower side in  FIG. 11 ) in the movable direction at the second position P 2 . The elastic holding portion  331  extends in the extending direction of the first wall portion  321 , an end  332  on the other end side (that is, the left side in  FIG. 11 ) thereof in the extending direction of the first wall portion  321  is connected to the first wall portion  321 , and an end  333  on one end side thereof in the extending direction of the first wall portion  321  is disposed between the first wall portion  321  and the operation surface  12  and configured to be elastically deformable in a direction away from the operation surface  12  in the movable direction. 
     Further, as shown in  FIG. 11 , a display portion  37  is provided on the first position P 1  side (that is, the left side in  FIG. 11 ) of the surface of the first wall portion  321  facing the operation surface  12 . The display portion  37  is composed of characters “UNLOCK” and arrows indicating the direction from the second position P 2  toward the first position P 1 . 
     As shown in  FIG. 7 , a locking portion  312  and a hold releasing portion  313  are provided on the facing surface  311  of the lever body  31 . The locking portion  312  is configured to be capable of locking a distal end  101  (see  FIGS. 25 and 26 ) which is one end in the extending direction of the long jig  100  used for moving the lever body  31  from the first position P 1  to the second position P 2 . Further, the hold releasing portion  313  is configured to be capable of releasing holding of the lever body  31  by the elastic holding portion  331  by pressing the lever body  31  from the other side to one side (that is, from the near side to the back in the paper penetration direction in  FIG. 7 ) in the movable direction at the second position P 2 . 
     Further, the lever body  31  is provided with a protection wall  314  that is disposed on the opposite side (that is, on the upper side in  FIG. 7 ) of the fulcrum forming surface  15  with respect to the hold releasing portion  313  in a direction intersecting with the fulcrum forming surface  15  and protects the hold releasing portion  313  in the direction intersecting with the fulcrum forming surface  15 . 
     Further, as shown in  FIG. 12 , the lock lever unit  30  has the lever support portion  34  connected to the lever body  31  so as to be movable together with the lever body  31 . As shown in  FIG. 13 , the lever support portion  34  is provided inside the housing portion  11  to surround the end  22  of the operation unit  20  on the housing portion  11  side in the circumferential direction (that is, around the movable direction), and is disposed so that an inner circumferential surface  341  of the lever support portion  34  faces the end  22  of the operation unit  20  on the housing portion  11  side. 
     As shown in  FIG. 12 , the lever support portion  34  is provided with the locking projection  342  that protrudes from the inner circumferential surface  341  toward the operation unit  20  (that is, toward the radial inside of the lever support portion  34 ). In this embodiment, as an example, four locking projections  342  are arranged at intervals in the circumferential direction of the inner circumferential surface  341  of the lever support portion  34 . 
     In addition, as shown in  FIG. 14 , the lever support portion  34  includes a lever connection portion  345 , which is an example of a connection portion, and an inclined portion  346 . 
     The lever connection portion  345  has a substantially annular shape, extends along the operation surface  12 , and houses the end  22  of the housing portion  11  of the operation unit  20  in a substantially circular through hole  344  at the center thereof. That is, the lever body  31  rotates around a rotation axis that passes through the center of the lever connection portion  345  and extends in the movable direction. Further, the lever connection portion  345  is connected to the operation unit  20  in a movable state in the movable direction together with the operation unit  20  when the lever body  31  is at the second position P 2 . The inclined portion  346  is connected to the lever connection portion  345  and the lever body  31 , and is inclined from the lever connection portion  345  toward the lever body  31  in an opening direction from the operation surface  12  toward the pressing surface  21  (hereinafter simply referred to as an opening direction) along the movable direction. 
     The lever connection portion  345  is provided with a plurality of cam projections  343  (in this embodiment, as an example, two cam projections  343 ) protruding radially outward from the outer circumferential surface of the lever support portion  34 . Specifically, the cam projections  343  are provided respectively on the outer circumferential surfaces  351  of a pair of legs  35  extending from the edge of the through hole  344  of the lever connection portion  345  along the movable direction in the direction away from the operation surface  12 . Further, each cam projection  343  has a quadrangular shape in which all corners are chamfered when viewed from the protruding direction. Each leg  35  is disposed on the same straight line passing through a center CP (shown in  FIG. 12 ) of the through hole  344 , and each cam projection  343  is configured so as to be engageable with each of a plurality of cam grooves  412  of the first plunger  41  described later. 
     Note that the transmission mechanism  50  is configured by the lever support portion  34 , the plurality of cam projections  343 , and the plurality of cam grooves  412 . That is, the transmission mechanism  50  is disposed between the lock lever unit  30  and the plunger  40 . 
     As shown in  FIG. 3 , the lever body  31  is provided with a display portion  36  on an exposed side surface that is not covered by the exterior portion  32  when viewed from a direction orthogonal to the fulcrum forming surface  15 . The display portion  36  is composed of characters “LOCK” and arrows indicating the direction from the first position P 1  to the second position P 2 . 
     As shown in  FIG. 8 , the plunger  40  is disposed at the end on the operation surface  12  side inside the housing portion  11 , and is configured to be movable along the movable direction between a return position P 3  (see  FIG. 19 ) away from the operation surface  12  and an operating position (see  FIG. 20 ) in the middle of the operation surface  12  and the return position P 3 . More specifically, as shown in  FIG. 15 , the plunger  40  has the first plunger  41  in a substantially rectangular plate shape and the second plunger  42  disposed in series with the first plunger  41  along the movable direction and disposed away from the operation surface  12 . The first plunger  41  and the second plunger  42  are not connected and are configured to be movable independently of each other. 
     As shown in  FIG. 16 , the first plunger  41  has a substantially circular through hole  411  provided at a substantially central portion and penetrating in a movable direction and a plurality of cam grooves (in this embodiment, as an example, two cam grooves)  412  provided on an inner circumferential surface  414  and mutually arranged at intervals (for example, at 180 degrees) in the circumferential direction of the inner circumferential surface  414 . In the through hole  411 , as shown in  FIG. 13 , the end  22  of the operation unit  20  on the housing portion  11  side is housed so as to be rotatable in the circumferential direction (that is, around the movable direction) of the inner circumferential surface  414 . 
     Each cam groove  412 , as viewed from the approaching direction, is inclined in a direction approaching the operation surface  12  (in other words, so as to be away from the operation surface  12  along the moving direction from the first position P 1  toward the second position P 2  of the lever body  31 ) as it advances in a clockwise direction along the circumferential direction of the inner circumferential surface  414  of the through hole  411 , and is disposed so as to be engageable with each cam projection  343  of the lever support portion  34  of the lock lever unit  30 . In other words, the inner circumferential surface  414  of the through hole  411  faces the outer circumferential surface  351  of each leg  35  of the lever support portion  34 , and each cam groove  412  corresponds to each cam projection  343 . Further, at each corner of the first plunger  41 , a circular recess  413  is provided. As shown in  FIG. 13 , a coil spring  71  is housed in each recess  413 . 
     As shown in  FIG. 17 , the second plunger  42  is provided with an annular main body  421  having a through hole  423  provided in the center, and a plurality of plunger connection portions (in this embodiment, as an example, four plunger connection portions)  422  provided radially outside the main body  421 . 
     The main body  421  is provided with an annular wall  424  protruding in a direction approaching the operation surface  12  from the peripheral portion of the through hole  423  at the center thereof along the movable direction (that is, upward in  FIG. 17 ). The annular wall  424  is configured to be insertable into the through hole  411  of the first plunger  41 . A partially annular recess  425  for housing the end  22  of the operation unit  20  on the housing portion  11  side is formed radially outside the annular wall  424  of the main body  421 . 
     The plunger connection portions  422  are arranged at intervals along the circumferential direction of the outer circumferential surface of the main body  421 . Each plunger connection portion  422  has a substantially rectangular parallelepiped shape extending from the main body  421  along the movable direction in a direction away from the operation surface  12  (that is, downward in  FIG. 17 ), and is connected to the contact mechanism  60 . 
     An LED unit  90  is disposed in the through hole  423  of the second plunger  42 , as shown in  FIG. 13 . 
       FIGS. 18 to 20  show a state in which the lock lever unit  30  and the plunger  40  are connected.  FIG. 19  is a plan view showing a state in which the lever body  31  is at the first position P 1  and the plunger  40  is at the return position P 3  as viewed from the direction indicated by the arrow A in  FIG. 18 , and  FIG. 20  is a plan view showing a state in which the lever body  31  is at the second position P 2  and the plunger  40  is at the operating position P 4  as viewed from the direction indicated by the arrow A in  FIG. 18 . 
     As shown in  FIGS. 19 and 20 , the first plunger  41  is configured to move from the return position P 31  to the operating position P 41  when the lever body  31  is moved from the first position P 1  to the second position P 2  by the transmission mechanism  50 , and move from the operating position P 41  to the return position P 31  when the lever body  31  is moved from the second position P 2  to the first position P 1 . The second plunger  42  is biased by a coil spring  72  described later in a direction approaching the operation surface  12  along the movable direction. Therefore, the second plunger  42  moves from the return position P 32  to the operating position P 42  with the movement of the first plunger  41  from the return position P 3  to the operating position P 4 , and moves from the operating position P 42  to the return position P 32  with the movement of the first plunger  41  from the operating position P 4  to the return position P 3 . When the second plunger  42  is not positioned at the return position P 32 , the second plunger  42  is configured to be movable to the return position P 32  along the movable direction by the approaching operation of the operation unit  20 . That is, the second plunger  42  is configured to be positioned at the return position P 32  by the approaching operation of the operation unit  20 . Note that, the second plunger  42 , when having moved to the return position P 32  due to the approaching operation of the operation unit  20 , is held at the return position P 32  by the end  22  of the operation unit  20  on the housing portion  11  side. 
     That is, the transmission mechanism  50  moves the plunger  40  from the return position P 3  to the operating position P 4  along the movable direction as the lever body  31  moves from the first position P 1  toward the second position P 2 , but it moves the plunger  40  from the operating position P 4  to the return position P 3  along the movable direction as the lever body  31  moves from the second position P 2  toward the first position P 1 . In other words, the transmission mechanism  50  has a function of transmitting the moving operation of the lever body  31  to the plunger  40 . 
     As shown in  FIG. 21 , the contact mechanism  60  includes a plurality of fixed contact portions  61  provided inside the housing portion  11  and a plurality of movable contact portions  62  provided respectively so as to face the fixed contact portions  61  in the movable direction inside the housing portion  11 . The fixed contact portions  61  are connected to the terminal connection mechanisms  16 , respectively. Each movable contact portion  62  is connected to any one of the four plunger connection portions  422  of the second plunger  42 , and is configured to contact the facing fixed contact portion  61  by movement of the second plunger  42  from the return position P 32  to the operating position P 42  and separate from the fixed contact portion  61  in contact by movement of the second plunger  42  from the operating position P 42  to the return position P 32 . In other words, the contact mechanism  60  is configured to be opened and closed by the movement of the second plunger  42  along the movable direction. 
     In more detail, the terminal connection mechanisms  16  are arranged in a line along the fulcrum forming surface  15  and the surface facing the fulcrum forming surface  15 . The fixed contact portion  61  connected to the terminal connection mechanism  16  (hereinafter, referred to as a first terminal connection mechanism  161 ) disposed along the fulcrum forming surface  15  and the facing movable contact portion  62  constitute an NO contact  63 , and the fixed contact portion  61  connected to the terminal connection mechanism  16  (hereinafter, referred to as a second terminal connection mechanism  162 ) disposed along the surface facing the fulcrum forming surface  15  and the facing movable contact portion  62  constitute an NC contact  64 . That is, when the lever body  31  is at the first position P 1 , as shown in  FIG. 22 , the NO contact  63  is closed and the NC contact  64  is opened, while when the lever body  31  is at the second position P 2 , as shown in  FIG. 23 , the NO contact  63  is opened and the NC contact  64  is closed. 
     The biasing portion  70  has a coil spring  71  (shown in  FIG. 13 ) as an example of a first biasing portion and a coil spring  72  (shown in  FIG. 8 ) as an example of a second biasing portion. 
     As shown in  FIG. 13 , the coil springs  71  are respectively arranged in the recesses  413  provided at the four corners of the first plunger  41  inside the housing portion  11 , and bias the plunger  40  from the operating position P 4  along the movable direction toward the return position P 3 . Specifically, the respective coil springs  71  are arranged in a state in which they are sandwiched between a bottom surface of the recess  413  of the first plunger  41  and an inner surface  111  (see  FIG. 24 ) constituting the housing portion  11  of the housing  10  facing the bottom surface, press the first plunger  41  in a direction away from the operation surface  12  along the movable direction, and bias the first plunger  41  from the operating position P 41  toward the return position P 31 . That is, the respective coil springs  71  are arranged so that the pressing on the first plunger  41  is even and bias the lever body  31  of the lock lever unit  30  from the second position P 2  toward the first position P 1  via the first plunger  41 . 
     As shown in  FIG. 8 , the coil spring  72  is disposed between the terminal connection surface  14  and the contact mechanism  60  along the movable direction inside the housing portion  11 , and biases the plunger  40  along the movable direction from the return position P 3  toward the operating position P 4 . More specifically, the coil spring  72  is disposed on a center line CL extending in the movable direction of the operation unit  20 , and is disposed in a state in which it presses a portion of the contact mechanism  60  facing the terminal connection surface  14  toward the operation surface  12  and biases the second plunger  42  along the movable direction from the return position P 32  toward the operating position P 42  via the contact mechanism  60 . 
     The coil spring  71  is configured so that the biasing force thereof is greater than the biasing force of the coil spring  72 . As a result, as long as the lever body  31  is not operated, the plunger  40  is always positioned at the return position P 3  and maintains a state in which the movable contact portion  62  of the NC contact  64  is separated from the fixed contact portion  61 , and thus the safety of the push-button switch  1  is ensured. 
     Next, referring to  FIG. 24 , when the lever body  31  of the lock lever unit  30  is positioned at the second position P 2 , the operation of the push-button switch  1  when the operation unit  20  is pulled from the operation surface  12  toward the pressing surface  21  along the movable direction (that is, in the opening direction indicated by the arrow B in  FIG. 24 ) will be described. 
     As shown in  FIG. 24 , a deformation portion  17  connected to the exterior portion  32  of the lock lever unit  30  and extending along the inclined portion  346  of the lever support portion  34  is provided on a wall  18  on the operation surface  12  side of the housing  10 . 
     When the lever body  31  of the lock lever unit  30  is positioned at the second position P 2 , the end  22  of the operation unit  20  on the housing portion  11  side and the lever support portion  34  of the lock lever unit  30  are movably connected together in the movable direction. Therefore, when the operation unit  20  is pulled in the opening direction, the lever support portion  34  is also pulled together in the opening direction. 
     When the lever support portion  34  is pulled in the opening direction, the inclined portion  346  of the lever support portion  34  moves toward the operation unit  20  and comes into contact with the deformation portion  17  of the housing  10 . The inclined portion  346  in contact with the deformation portion  17  is deformed in the approaching direction, moves the lever body  31  in the approaching direction, and releases the pressing to the lever body  31  by the holding unit  33 . When the pressing to the lever body  31  by the holding unit  33  is released, the lever body  31  moves from the second position P 2  to the first position P 1  by the coil spring  71 , and the movable contact portion  62  of the NC contact  64  is separated from the corresponding fixed contact portion  61 . 
     Subsequently, the operation of the lever body  31  using the jig  100  will be described with reference to  FIGS. 25 and 26 . 
     First, as shown in  FIG. 25 , the distal end  101  of the jig  100  is locked to the locking portion  312  of the lever body  31  at the first position P 1 . At this time, the jig  100  is disposed so that the intermediate portion  102  thereof contacts the curved surface  152  of the fulcrum projection  151 . 
     Then, the jig  100  is rotated clockwise in  FIG. 25  while the distal end  101  is locked to the locking portion  312  with the curved surface  152  of the fulcrum projection  151  contacting the intermediate portion  102  of the jig  100  as a rotation fulcrum. As a result, the lever body  31  moves from the first position P 1  to the second position P 2 , as shown in  FIG. 26 . 
     As described above, in the push-button switch  1 , it is possible to move the lever body  31  from the first position P 1  to the second position P 2  using the jig  100 . 
     As described above, according to the push-button switch  1 , the plunger  40  has the first plunger  41  that can move between the return position P 3  and the operating position P 4  by the transmission mechanism  50  of the lock lever unit  30 , and the second plunger  42  that is disposed in series with respect to the first plunger  41  and disposed farther away from the operation surface  12  than the first plunger  41 , and can move to the return position P 3  by the operation unit  20 . The first plunger  41  and the second plunger  42  can move independently of each other, and are configured so that the movable contact portion  62  contacts with or separates from the fixed contact portion  61  by the movement of the second plunger  42 . That is, in the push-button switch  1 , it is possible to ensure the contact reliability of the movable contact portion  62  with respect to the fixed contact portion  61  by merely ensuring the positional accuracy of the second plunger  42  and the contact mechanism  50  without being affected by the securement of the positional accuracy of the lock lever unit  30 . For this reason, for example, the contact reliability of the fixed contact portion  61  and the movable contact portion  62  can be ensured more easily than that of the operation switch of PTL 1 in which the positional accuracy of the lock lever, the cam, the holder, and the contact B needs to be ensured. 
     Further, the first plunger  41  has the through hole  411  that penetrates in the movable direction and a plurality of cam grooves  412  which are provided on the inner circumferential surface  414  of the through hole  411  and arranged at an interval from each other in the circumferential direction of the inner circumferential surface  414 , and which are respectively inclined so as to be away from the operation surface  12  along the moving direction of the lever body  31  from the first position P 1  toward the second position P 2 , and the lock lever unit  30  has the lever support portion  34  which is disposed in the through hole  411  and extends along the inner circumferential surface  414  of the through hole  411  and a plurality of cam projections  343  which are provided so as to respectively correspond to the plurality of cam grooves  412  and which protrude from the outer circumferential surface  351  facing the inner circumferential surface  414  of the lever support portion  34  and respectively engage with the corresponding plurality of cam grooves  412 . The transmission mechanism  50  includes a plurality of cam grooves  412 , a lever support portion  34 , and a plurality of cam projections  343 . The transmission mechanism  50  can move the entire plunger  40  more reliably along the movable direction, so that the contact reliability of the fixed contact portion  61  and the movable contact portion  62  can be ensured. 
     According to the push-button switch  1 , the lever body  31  of the lock lever unit  30  has the locking portion  312  that can lock the one end  101  of the long jig  100  in the extending direction thereof, and the housing  10  has a fulcrum projection  151  that contacts the intermediate portion  102  of the jig  100  in which one end  101  is locked to the locking portion  312  when the lever body  31  of the lock lever unit  30  is moved from the first position P 1  to the second position P 2  using the jig  100 , and serves as a rotation fulcrum of the jig  100 . Due to the locking portion  312  and the fulcrum projection  151 , even when, for example, a large force is required for the rotation operation of the lever body  31  of the lock lever unit  30 , the leverage principle is generated by using the jig  100 , and the lever body  31  of the lock lever unit  30  can be easily rotated with a smaller force. 
     The holding unit  33  has an elastic holding portion  331  capable of holding the lever body  31  by pressing the lever body  31  from one side to the other side in the movable direction at the second position P 2  and a hold releasing portion  313  capable of releasing the holding of the lever body  31  by the elastic holding portion  331  by pressing the lever body  31  from the other side to one side in the movable direction at the second position P 2 . With the elastic holding portion  331  and the hold releasing portion  313 , the lever body  31  can be held at the second position P 2 , and the holding of the lever body  31  by the elastic holding portion  331  can be released with a simpler configuration. 
     Further, the lever body  31  has a protection wall  314  disposed on the opposite side of the fulcrum forming surface  15  with respect to the hold releasing portion  313  in the direction intersecting the fulcrum forming surface  15  and protecting the hold releasing portion  313  in the direction intersecting the fulcrum forming surface  15 . The protection wall  314  can reduce erroneous operation of the hold releasing portion  313 . 
     The fulcrum projection  151  has a curved surface  152  provided at a portion in contact with the intermediate portion  102  of the jig  100  and protruding from the fulcrum projection  151  toward the jig  100 . Due to the curved surface  152 , the rotation fulcrum of the jig  100  becomes constant, and the lever body  31  can be operated more easily by using the jig  100 . 
     Further, the fulcrum projection  151  is disposed closer to the first position P 1  than the center between the first position P 1  and the second position P 2  in the moving direction of the lever body  31  when viewed from a direction orthogonal to the fulcrum forming surface  15 . Thus, the lever body  31  can be operated more easily by using the jig  100 . 
     According to the push-button switch  1 , the housing  10  has a deformation portion  17  that, when the operation unit  20  is pulled in the opening direction in which it is separated from the housing  10  when the lever body  31  is positioned at the second position P 2 , contacts the lever support portion  34  to move the lever body  31 , and deforms the lever body  31  so as to be capable of releasing the pressing to the lever body  31  by the holding unit  33 . Due to this deformation portion  17 , when the lever body  31  is held by the holding unit  33  in a state in which the lever body  31  is at the second position P 2  and the movable contact portion  62  is in contact with the fixed contact portion  61 , even if the operation unit  20  is pulled in the opening direction in which it is separated from the housing  10 , since the holding of the lever body  31  by the holding unit  33  can be released, and the movable contact portion  62  can be separated from the fixed contact portion  61 , it is possible to realize the push-button switch  1  capable of easily ensuring safety. 
     Further, the lever body  31  is disposed between the pressing surface  21  and the operation surface  12  in the movable direction, and the lever support portion  34  has the lever connection portion  345  that extends along the operation surface  12  and is connected to the operation unit  20  so as to be movable in the movable direction together with the operation unit  20  when the lever body  31  is at the second position P 2 , and the inclined portion  346  that is connected to the lever connection portion  345  and the lever body  31  and is inclined in the opening direction from the lever connection portion  345  toward the lever body  31 . In addition, the deformation portion  17  is disposed facing the inclined portion  346  and capable of contacting the inclined portion  346 , and when the operation unit  20  is pulled in the opening direction, the deformation portion  17  contacts the inclined portion  346  to move the lever body  31  in the approaching direction and deforms the lever body  31  so as to be capable of releasing the pressing to the lever body  31  by the holding unit  33 . Accordingly, when the lever body  31  is held by the holding unit  33  in a state in which the lever body  31  is at the second position P 2  and the movable contact portion  62  is in contact with the fixed contact portion  61 , even if the operation unit  20  is pulled in the opening direction in which it is separated from the housing  10 , the holding of the lever body  31  by the holding unit  33  can be released more reliably, and the movable contact portion  62  can be separated from the fixed contact portion  61 . 
     According to the push-button switch  1 , it includes a lock lever unit  30  having a lever body  31  movable between a first position P 1  and a second position P 2  and a holding unit  33  capable of holding the lever body  31  at the second position P 2 , a transmission mechanism  50  that moves the plunger  40  from the return position P 3  to the operating position P 4  as the lever body  31  moves from the first position P 1  toward the second position P 2 , but moves the plunger  40  from the operating position P 4  to the return position P 3  as the lever body  31  moves from the second position P 2  toward the first position P 1 , a movement regulating portion  80  that, when the lever body  31  is positioned at the first position P 1 , enables movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at an initial position, but disables movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position, and a coil spring  71  that biases the plunger  40  from the operating position P 4  toward the return position P 3 . That is, in the push-button switch  1 , for example, when the operation unit  20  once removed for maintenance or the like is attached to the housing  10 , when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position, the lever body  31  can be moved to the second position P 2  and held by the holding unit  33 , but when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position in the movable direction, the lever body  31  cannot be moved to the second position P 2 , and the lever body  31  is biased by the first biasing portion  71  via the plunger  40  to move to the first position P 1 . This makes it possible to realize a push-button switch  1  to which the operation unit  20  can be reliably attached in a complete state. 
     Further, a coil spring  72  that is provided inside the housing portion  11  and biases the plunger  40  from the return position P 3  toward the operating position P 4  along the movable direction is further provided, and is configured so that the biasing force of the coil spring  71  is greater than the biasing force of the coil spring  72 . The plunger  40  has a first plunger  41  that is disposed so as to be able to be biased by the coil spring  71 , and is movable along the movable direction between the return position P 31  and the operating position P 41  by the transmission mechanism  50  as the lever body  31  moves between the first position P 1  and the second position P 2 , and a second plunger  42  that is disposed farther away from the operation surface  12  along the movable direction than the first plunger  41  in a state capable of being biased by the coil spring  72  and disposed in series with the first plunger  41  along the movable direction, and is positioned at the return position P 32  by the approaching operation of the operation unit  20 . Further, the first plunger  41  and the second plunger  42  can move independently of each other along the movable direction, and are configured so that the movable contact portion  62  contacts with or separates from the fixed contact portion  61  by the movement of the second plunger  42  along the movable direction. This makes it possible to ensure the contact reliability of the movable contact portion  62  with respect to the fixed contact portion  61  by merely ensuring the positional accuracy of the second plunger  42  and the contact mechanism  50  without being affected by the securement of the positional accuracy of the lock lever unit  30 . 
     Further, the first plunger  41  has a through hole  411  that penetrates in the movable direction and a plurality of cam grooves  412  which are provided on the inner circumferential surface  414  of the through hole  411  and are arranged at an interval from each other in the circumferential direction of the inner circumferential surface  414  and which are respectively inclined away from the operation surface  12  along the moving direction of the lever body  31  from the first position P 1  toward the second position P 2 , and the lever support portion  34  has a plurality of cam projections  343  which are arranged in the through hole  411  and extend along the inner circumferential surface  414  of the through hole  411  and which are provided so as to respectively correspond to the plurality of cam grooves  412 , protrude from the outer circumferential surface  351  facing the inner circumferential surface  414  of the lever support portion  34  toward the inner circumferential surface  414 , and respectively engage with the corresponding plurality of cam grooves  412 . The transmission mechanism  50  includes a plurality of cam grooves  412 , a lever support portion  34 , and a plurality of cam projections  343 . The transmission mechanism  50  can move the entire plunger  40  more reliably along the movable direction, so that the contact reliability of the fixed contact portion  61  and the movable contact portion  62  can be ensured. 
     Further, the lever support portion  34  surrounds the end  22  of the operation unit  20  on the housing portion  11  side in the circumferential direction (that is, around the movable direction), has an inner circumferential surface  341  disposed so as to face the end  22  of the operation unit  20  on the housing portion  11  side, and has a locking projection  342  protruding from the inner circumferential surface  341  toward the operation unit  20 , and the end  22  of the operation unit  20  on the housing portion  11  side has a first groove  23  extending in the movable direction and capable of housing the locking projection  342  when the lever body  31  is at the first position P 1  and a second groove  24  which is connected to the end  231  of the first groove  23  on the pressing surface  21  side in the movable direction and extends along the circumferential direction of the end  22  of the operation unit  20  on the housing portion  11  side so as to be capable of housing the locking projection  342  and which locks the locking projection  342  in the movable direction when the lever body  31  is at the second position P 2 . The movement regulating portion  80  includes the locking projection  342 , the first groove  23 , and the second groove  24 . Accordingly, the movement of the lever body  31  to the second position can be regulated with a simple configuration, so that it is possible to easily realize the push-button switch  1  to which the operation unit  20  can be reliably attached in a complete state. 
     Further, the first biasing portion is configured by a plurality of coil springs  71 . Thus, with a simple configuration, the plunger  40  can be biased from the operating position P 4  toward the return position P 3  along the movable direction. 
     Further, the second biasing portion is configured by at least one coil spring  72 . Thereby, with a simple configuration, the plunger  40  can be biased from the return position P 3  toward the operating position P 4  along the movable direction. 
     The configuration other than the housing  10 , the plunger  40 , the operation unit  20 , the lock lever unit  30 , the transmission mechanism  50 , the movement regulating portion  80 , the contact mechanism  60 , and the first biasing portion  71  may be omitted if possible, or may be replaced with a configuration different from the push-button switch  1 . For example, the deformation portion  17  and the fulcrum projection  151  of the housing  10  may be omitted. 
     The transmission mechanism  50  is not limited to the case where it includes the lever support portion  34 , the plurality of cam projections  343 , and the plurality of cam grooves  412 . The transmission mechanism  50  can adopt any configuration that can move the plunger  40  from the return position P 3  to the operating position P 4  as the lever body  31  moves from the first position P 1  toward the second position P 2 , but can move the plunger  40  from the operating position P 4  to the return position P 3  as the lever body  31  moves from the second position P 2  toward the first position P 1 . 
     The contact mechanism  60  can adopt a contact mechanism with any configuration as long as it includes a fixed contact portion  61  and a movable contact portion  62  that is provided so as to face the fixed contact portion  61  in the movable direction, contacts the fixed contact portion  61  when the plunger  40  moves from the return position P 3  to the operating position P 4 , and separates from the fixed contact portion  61  when the plunger  40  moves from the operating position P 4  to the return position P 3 . 
     The lever connection portion  345  of the lever support portion  34  is not limited to a substantially annular shape, and may be, for example, a semi-circular shape. 
     The holding unit  33  is not limited to the case where it is configured by the elastic holding portion  331 , and any configuration can be adopted as long as the lever body  31  can be held at the second position P 2 . Further, the hold releasing portion  313  can be appropriately changed according to the configuration of the holding unit  33 . 
     The protection wall  314  is not limited to the case where it is provided on the lever body  31 , but may be provided on the exterior portion  32 , for example. 
     The fulcrum projection  151  is not limited to a case having an oval shape. For example, as shown in  FIG. 27 , it may be a fulcrum projection  151  having a curved surface  152  only on a side in contact with the intermediate portion  102  of the jig  100  in its extending direction when viewed from a direction orthogonal to the fulcrum forming surface  15 . Further, as shown in  FIG. 28 , it may be a fulcrum projection  151  having a curved surface  152  protruding in a direction away from the jig  100  on a side in contact with the intermediate portion  102  of the jig  100  in its extending direction when viewed from a direction orthogonal to the fulcrum forming surface  15 . Further, as shown in  FIG. 29 , it may be a fulcrum projection  151  having a through hole  153  penetrating in the movable direction. In this case, the inner circumferential surface of the through hole  153  contacts the intermediate portion  102  of the jig  100  and serves as a rotation fulcrum of the jig  100 . 
     The first biasing portion is not limited to a case where it is configured by a plurality of coil springs  71 , and can adopt a biasing portion with any configuration capable of biasing the plunger  40  from the operating position P 4  toward the return position P 3  along the movable direction. For example, the first biasing portion may be configured by a single or three or more coil springs  71 . 
     The second biasing portion is not limited to a case where it is configured by a single coil spring  72 , and can adopt a biasing portion with any configuration capable of biasing the plunger  40  from the return position P 3  toward the operating position P 4  along the movable direction. For example, the second biasing portion may be configured by a plurality of coil springs  72 . 
     It is sufficient that the plunger  40  has a first plunger  41  and a second plunger  42  and is movable between the return position P 3  and the operating position P 4  along the movable direction, and its shape and the like can be changed as appropriate by the design and the like of the push-button switch  1 . 
     It is sufficient that the deformation portion  17  is configured such that when the operation unit  20  is pulled in the opening direction in which the operation unit  20  is separated from the housing  10  while the lever body  31  is positioned at the second position P 2 , the deformation portion  17  contacts the lever support portion  34  to move the lever body  31 , and deforms the lever body  31  so as to be capable of releasing the pressing to the lever body  31  by the holding unit  33 . That is, the shape and the like of the deformation portion  17  can be appropriately changed according to the shape and the like of the lever body  31  and the lever support portion  34 . 
     The movement regulating portion  80  is not limited to the case where it includes the locking projection  342 , the first groove  23 , and the second groove  24 . The movement regulating portion  80  can adopt any configuration that, when the lever body  31  is positioned at the first position P 1 , enables the movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position, but disables the movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position. 
     As described above, various embodiments of the present disclosure have been described in detail with reference to the drawings, and finally, various aspects of the present disclosure will be described. In the following description, description will be provided with reference numerals attached thereto as an example. 
     The push-button switch  1  according to the first aspect of the present disclosure includes: 
     a housing  10  having an operation surface  12  provided with an operation hole  13  and a housing portion  11  provided therein and connected to the operation hole  13 ; 
     a plunger  40  provided at an inside of the housing portion  11  and movable between a return position P 3  away from the operation surface  12  and an operating position P 4  in the middle between the operation surface  12  and the return position P 3  along a movable direction intersecting the operation surface  12 ; 
     an operation unit  20  that extends along the movable direction from an outside of the housing  10  through the operation hole  13  to the inside of the housing portion  11  and is mounted to the housing  10  in a state in which an end  22  on the housing portion  11  side in an extending direction is positioned at an initial position, and has a pressing surface  21  provided at the outside of the housing  10  and disposed so as to face the operation surface  12 , in which the pressing surface  21  is capable of an approaching operation with respect to the operation surface  12  along the movable direction, and the end  22  on the housing portion  11  side moves from the initial position to a pressing position to position the plunger  40  at the return position P 3  by the approaching operation; 
     a lock lever unit  30  that has a lever body  31  exposed to the outside of the housing  10  and movable in a direction intersecting the movable direction between a first position P 1  and a second position P 2 , a lever support portion  34  provided at the inside of the housing portion  11  and connected to the lever body  31  so as to be movable together with the lever body  31 , and a holding unit  33  capable of holding the lever body  31  at the second position; 
     a transmission mechanism  50  that is provided between the lock lever unit  30  and the plunger  40  inside the housing portion  11 , moves the plunger  40  from the return position P 3  to the operating position P 4  along the movable direction as the lever body  31  moves from the first position P 1  toward the second position P 2 , and moves the plunger  40  from the operating position P 4  to the return position P 3  along the movable direction as the lever body  31  moves from the second position P 2  toward the first position P 1 ; 
     a movement regulating portion  80  that is provided between the operation unit  20  and the lock lever unit  30  inside the housing portion  11 , and when the lever body  31  is positioned at the first position P 1 , enables movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position, and disables movement of the lever body  31  to the second position P 2  when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position in the movable direction; 
     a contact mechanism  60  that has a fixed contact portion  61  provided at the inside of the housing portion  11  and a movable contact portion  62  that is provided at the inside of the housing portion  11  so as to face the fixed contact portion  61 , comes into contact with the fixed contact portion  61  when the plunger  40  moves from the return position P 3  to the operating position P 2 , and separates from the fixed contact portion  61  when the plunger  40  moves from the operating position P 3  to the return position P 2 ; and 
     a first biasing portion  71  provided inside the housing portion  11  and biasing the plunger  40  from the operating position P 4  toward the return position P 3  along the movable direction. 
     According to the push-button switch  1  of the first aspect, for example, when the operation unit  20  once removed for maintenance or the like is attached to the housing  10 , when the end  22  of the operation unit  20  on the housing portion  11  side is positioned at the initial position, the lever body  31  can be moved to the second position P 2  and held by the holding unit  33 , while when the end  22  of the operation unit  20  on the housing portion  11  side is positioned closer to the operation surface  12  than the initial position in the movable direction, the lever body  31  cannot be moved to the second position P 2 , and the lever body  31  is biased by the first biasing portion  71  via the plunger  40  to move to the first position P 1 . This makes it possible to realize a push-button switch  1  to which the operation unit  20  can be reliably attached in a complete state. 
     The push-button switch  1  according to the second aspect of the present disclosure further includes: 
     a second biasing portion  72  provided inside the housing portion  11  and biasing the plunger  40  from the return position P 3  toward the operating position P 4  along the movable direction, in which 
     the biasing force of the first biasing portion  71  is configured to be larger than the biasing force of the second biasing portion  72 , 
     the plunger  40  has 
     a first plunger  41  disposed capable of being biased by the first biasing portion  71  and movable along the movable direction between the return position P 3  and the operating position P 4  by the transmission mechanism  50  as the lever body  31  moves between the first position P 1  and the second position P 2 , and 
     a second plunger  42  that is disposed farther away from the operation surface  12  along the movable direction than the first plunger  41  in a state capable of being biased by the second biasing portion  72  and disposed in series with the first plunger  41  along the movable direction, and is positioned at the return position P 3  by the approaching operation of the operation unit  20 , 
     the first plunger  41  and the second plunger  42  are movable along the movable direction independently of each other, and 
     the movable contact portion  62  is configured to contact with or separate from the fixed contact portion  61  by movement of the second plunger  42  along the movable direction. 
     According to the push-button switch  1  of the second aspect, the contact reliability of the movable contact portion  62  with respect to the fixed contact portion  61  can be ensured only by ensuring the positional accuracy of the second plunger  42  and the contact mechanism  50  without being affected by the securement of the positional accuracy of the lock lever unit  30 . 
     In the push-button switch  1  according to the third aspect of the present disclosure, 
     the first plunger  41  has 
     a plurality of cam grooves  412  which are provided on the inner circumferential surface  414  of the through hole  411  that penetrates in the movable direction and disposed at an interval from each other in the circumferential direction of the inner circumferential surface  414  and which are respectively inclined so as to separate from the operation surface  12  along the moving direction from the first position P 1  of the lever body  31  toward the second position P 2 , 
     the lever support portion  34   
     is disposed in the through hole  411  and extends along the inner circumferential surface  414  of the through hole  411 , and 
     has a plurality of cam projections  343  which are provided so as to respectively correspond to the plurality of cam grooves  412  and protrude from the outer circumferential surface  351  facing the inner circumferential surface  414  of the lever support portion  34  toward the inner circumferential surface  414  and which respectively engage with the corresponding plurality of cam grooves  412 , and 
     the transmission mechanism  50  includes the plurality of cam grooves  412 , the lever support portion  34 , and the plurality of cam projections  343 . 
     According to the push-button switch  1  of the third aspect, the entirety of the plunger  40  can be more reliably moved along the movable direction by the transmission mechanism  50 , so that the contact reliability of the fixed contact portion  61  and the movable contact portion  62  can be ensured. 
     In the push-button switch  1  according to the fourth aspect of the present disclosure, 
     the second biasing portion is configured by at least one coil spring. 
     According to the push-button switch  1  of the fourth aspect, the plunger  40  can be biased from the operating position P 4  toward the return position P 3  along the movable direction with a simple configuration. 
     In the push-button switch  1  according to the fifth aspect of the present disclosure, 
     the first biasing portion is configured by a plurality of coil springs. 
     According to the push-button switch  1  of the fifth aspect, the plunger  40  can be biased from the return position P 3  toward the operating position P 4  along the movable direction with a simple configuration. 
     In the push-button switch  1  according to the sixth aspect of the present disclosure, 
     the lever support portion  34  surrounds the end  22  of the operation unit  20  on the housing portion  11  side around the movable direction, has an inner circumferential surface  341  disposed so as to face the end  22  of the operation unit  20  on the housing portion  11  side, and has a locking projection  342  protruding from the inner circumferential surface  341  toward the operation unit  20 , 
     the end  22  of the operation unit  20  on the housing portion  11  side has 
     a first groove  23  extending in the movable direction and capable of housing the locking projection  342  when the lever body  31  is at the first position P 1 , and 
     a second groove  24  which is connected to the end of the first groove  23  on the pressing surface  21  side in the movable direction and extends along the circumferential direction of the end  22  of the operation unit  20  on the housing portion  11  side so as to be capable of housing the locking projection  342  and which locks the locking projection  342  in the movable direction when the lever body  31  is at the second position P 2 , and 
     the movement regulating portion  80  includes the locking projection  342 , the first groove  23 , and the second groove  24 . 
     According to the push-button switch  1  of the sixth aspect, the movement of the lever body  31  to the second position can be regulated with a simple configuration, so that the push-button switch  1  capable of reliably attaching the operation unit  20  in a complete state can be easily realized. 
     In addition, by appropriately combining any of the above-described various embodiments or modifications, the effects of the respective embodiments or modifications can be achieved. In addition, a combination of the embodiments or a combination of the examples or a combination of the embodiment and the example is possible, and a combination of the features in the different embodiments or the examples is also possible. 
     Although the present disclosure has been fully described in connection with preferred embodiments with reference to the accompanying drawings, various variations and modifications will be apparent to those skilled in the art. It is to be understood that such variations and modifications are included therein unless they depart from the scope of the present disclosure as set forth in the appended claims. 
     INDUSTRIAL APPLICABILITY 
     The push-button switch of the present disclosure can be applied to, for example, an emergency stop switch. 
     REFERENCE SIGNS LIST 
     
         
         
           
               1 . push-button switch 
               10 . housing 
               11 . housing portion 
               12 . operation surface 
               13 . operation hole 
               14 . terminal connection surface 
               141 . opening 
               15 . fulcrum forming surface 
               151 . fulcrum projection 
               152 . curved surface 
               16 . terminal connection mechanism 
               161 . first terminal connection mechanism 
               162 . second terminal connection mechanism 
               17 . deformation portion 
               18 . wall 
               20 . operation unit 
               21 . pressing surface 
               22 . end 
               23 . first groove 
               231 . end 
               24 . second groove 
               25 ,  26 . display portion 
               30 . lock lever unit 
               301 . lever portion 
               31 . lever body 
               311 . facing surface 
               312 . locking portion 
               313 . hold releasing portion 
               314 . protection wall 
               32 . exterior portion 
               321 . first wall portion 
               322 . second wall portion 
               323 . third wall portion 
               33 . holding unit 
               331 . elastic holding portion 
               332 ,  333 . end 
               34 . lever support portion 
               341 . inner circumferential surface 
               342 . locking projection 
               343 . cam projection 
               344 . through hole 
               345 . lever connection portion 
               346 . inclined portion 
               35 . leg 
               351 . outer circumferential surface 
               36 ,  37 . display portion 
               40 . plunger 
               41 . first plunger 
               411 . through hole 
               412 . cam groove 
               413 . recess 
               414 . inner circumferential surface 
               42 . second plunger 
               421 . main body 
               422 . plunger connection portion 
               423 . through hole 
               424 . annular wall 
               50 . transmission mechanism 
               60 . contact mechanism 
               61 . fixed contact portion 
               62 . movable contact portion 
               63 . NO contact 
               64 . NC contact 
               70 . biasing portion 
               71 ,  72 . coil spring 
               80 . movement regulating portion 
               90 . LED unit 
               100 . jig 
               101 . distal end 
               102 . intermediate portion 
             P 1 . first position 
             P 2 . second position 
             P 3 , P 31 , P 32 . return position 
             P 4 , P 41 , P 42 . operating position 
             A, B. arrow 
             CP. center 
             CL. center line