Abstract:
The pushing operability is freely adjustable. A switch device includes a switch including a push-in operable operation part; a housing attached to the switch; a push-in unit, turnably attached to the housing, for pushing in the operation part; a biasing unit, arranged in the housing, for biasing the push-in unit to position the operation part at a non-push-in position before being pushed in; and a biasing force adjusting unit for adjusting the biasing force applied on the push-in unit by the biasing unit at multi-levels or no level.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a switch device, in particular, to a switch device having a function of adjusting operating force when opening and closing the switch.  
         [0003]     2. Description of the Related Art  
         [0004]     Conventionally, a switch device in which a transmission member is turned about a turning axis by pushing in an operation member arranged at an opening of a case main body, and the operation load is adjusted by the positional relationship of the transmission force point and the transmission acting point of the transmission member and the pushing member is known (see, for example, Japanese Patent Application Laid-Open No. 9-293426).  
         [0005]     However, in the conventional switch device, the operation load can be adjusted by changing a component of the switch at the assembly stage, but the operation load cannot be adjusted after actually incorporated in a device. When miniaturization of the switch such as a mouse etc. to be connected to a computer is desired, the space for obtaining an adjusting amount of the operation load is insufficient with the adjustment method by the positional relationship of the transmission force point and the transmission acting point, and thus only a slight adjustment width can be ensured. Fingers may become tired within a short period of time when the push-in operation force is too strong in the operation switch for use as a mouse for games etc. with which push-in operation is frequently performed as compared with the conventional personal computer operation. When the push-in operation force is too weak, clicking is sometimes performed by mistake at unnecessary locations. Thus, enhancement of detailed operability that meets the need of the user and adjustment of load at the time of device assembly and at the time of operation are desired.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention aims to provide a switch device in which a load can be freely adjusted at the time of device assembly and at the time of operation.  
         [0007]     In order to overcome the above problem, the present invention proposes a switch device including: a switch including a push-in operable operation part; a housing attached to the switch; a push-in unit turnably attached to the housing to push in the operation part; a biasing unit arranged in the housing, for biasing the push-in unit to position the operation part at a non-push-in position before being pushed in; and a biasing force adjusting unit for adjusting the biasing force applied on the push-in unit by the biasing unit at multi-levels or no level.  
         [0008]     According to such configuration, the operation part of the switch is pushed in when the push-in unit is turned thereby turning ON the switch. The push-in operation of the push-in unit is performed against the biasing force of the biasing unit, and the biasing unit is adjusted at multi-levels or no level by the biasing force adjusting unit. Therefore, the force necessary to push in the push-in unit can be freely set according to the need of the user, thereby enhancing the operability.  
         [0009]     The biasing force adjusting unit may have a configuration in which a distance to the push-in unit in which the biasing unit is arranged is adjustable.  
         [0010]     The switch device may further include a holding unit arranged in a reciprocating manner in the housing, and the biasing unit is preferably held between the holding unit and the push-in unit; and the biasing force adjusting unit contacts the holding unit to adjust the position in the reciprocating direction.  
         [0011]     Preferably, the biasing unit includes a coil spring; the holding unit includes a spring holder of a bottomed tubular shape in which one end side of the coil spring is arranged, the spring holder including a projection passing through the housing and projecting to the side opposite from the push-in unit; and the biasing force adjusting unit is rotatably attached to the housing on the side opposite from the push-in unit, is contacted by the projection passed through the housing and projected, and includes a contacting part for displacing the position in the reciprocating direction with respect to the projection by being rotated.  
         [0012]     According to such configuration, that is, according to the configuration of the rotation-operated biasing force adjusting unit, the contacting position with respect to the projection of the spring holder by the contacting part can be displaced in the reciprocating direction of the spring holder. Therefore, compact configuration is achieved without requiring a wide occupying space.  
         [0013]     The contacting part of the spring holder is preferably configured by a plurality of supporting boards continuous in a staircase pattern in the rotating direction.  
         [0014]     According to such configuration, when the biasing force adjusting unit is rotation-operated, the contacting part of the spring holder sequentially moves to the adjacent supporting board. Therefore, click feeling is obtained according to the rotating operation of the biasing force adjusting unit.  
         [0015]     Each supporting board preferably includes an engagement concave part with which the projection of the spring holder is detachably engaged.  
         [0016]     According to such configuration, the projection moved to each supporting board is engaged with the engagement concave part, and a positional shift is prevented. Therefore, adjustment of the biasing force by the biasing force adjusting unit is performed in a stable state.  
         [0017]     Preferably, the switch is mounted on a substrate; and the biasing force adjusting unit is slidably arranged on the substrate, and is configured by a slide member for displacing the reciprocating position of the holding unit by the slide position.  
         [0018]     According to the present invention, the biasing force acting on the push-in unit is adjusted at multi-levels or no level, whereby the operability that meets the preference of the user is obtained, and furthermore, it can be easily assembled by simply attaching a housing etc. using an existing switch. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]      FIG. 1  shows a perspective view of a switch device according to an embodiment of the present invention;  
         [0020]      FIG. 2  shows an exploded perspective view of the switch device shown in  FIG. 1 ;  
         [0021]      FIG. 3  shows a front view of the switch device shown in  FIG. 1 ;  
         [0022]      FIG. 4  shows a cross sectional view of  FIG. 3 ;  
         [0023]      FIG. 5  shows a perspective view of a housing shown in  FIG. 2 ;  
         [0024]      FIG. 6  shows a front view of the housing shown in  FIG. 5 ;  
         [0025]      FIG. 7  shows a perspective view of an adjustment dial shown in  FIG. 2 ;  
         [0026]      FIG. 8  shows a plan view of the adjustment dial shown in  FIG. 7 :  
         [0027]      FIG. 9  shows a perspective view showing a state in which the switch device shown in  FIG. 1  is attached to a printed substrate;  
         [0028]      FIG. 10  shows a front view of  FIG. 9 :  
         [0029]      FIG. 11  shows a perspective view showing a state in which a switch device according to another embodiment is attached to the printed substrate;  
         [0030]      FIG. 12  shows a partially cut-out plan view of  FIG. 11 ;  
         [0031]      FIG. 13  shows a cross sectional view of  FIG. 11 ; and  
         [0032]      FIG. 14  shows a cross sectional view of a switch device according to another embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]     Embodiments of the present invention will now be described with reference to the accompanying drawings.  
       First Embodiment  
       [0034]     FIGS.  1  to  3  show a switch device SW according to the first embodiment. The switch device SW is generally configured by a switch  1 , a housing  2 , a drive lever  3 , and an adjustment dial  4 .  
         [0035]     The conventionally well-known switch  1  (see e.g., Japanese Patent Application Laid-Open No. 4-249015) has a button  6  or an operation unit exposed on the upper surface of a case  5 , as shown in  FIG. 4 . When the button  6  is pushed in, a movable contact strip  7  incorporated therein is driven, and a movable contacting point  8  arranged at the tip thereof contacts a fixed contacting point  9  arranged at a position facing thereto. A through hole  10   a  is formed at two locations on the side surface of a base  10 . The through hole  10   a  is used to screw the switch  1  itself to another member, and is formed in the existing switch  1  from the beginning. Various terminals  10   b  are projected from the lower surface of the base  10  to be mountable to a printed substrate P.  
         [0036]     The housing  2  is obtained by molding and processing a synthetic resin material (e.g., polyacetal resin (POM: polyoxymethylene)), and is configured by a housing main body  11 , and a pair of flat plates  12  extending therefrom, as shown in  FIGS. 5 and 6 .  
         [0037]     The housing main body  11  includes a middle part  13  having a substantially circular cross section, and a collar part  13   a  having a substantially rectangular shape in plan view is formed at the upper end of the middle part  13 . A concave part  13   b  having a circular shape in plan view when seen from above is formed in the housing main body  11 . The concave part  13   b  is formed at a position shifted from the axial center of the middle part  13 , and a through hole  13   c  is perforated at the center of the bottom surface. A spring holder  14  can be arranged in the concave part  13   b . A stopper part  15  extending laterally and then downward is formed at the external surface of the middle part  13 . The lower end of the stopper part  15  projects downward further than the lower surface of the middle part  13 . A supporting shaft  16  is arranged at the central part of the lower surface of the middle part  13 . An annular groove  16   a  is formed at the distal end side of the supporting shaft  16 , and a fixed ring  17  is attached thereto. The concave part  13   b  and the through hole  13   c  are arranged at a position substantially point symmetric with respect to the stopper part  15  with the supporting shaft  16  at the center.  
         [0038]     The flat plate  12  is formed with a concave portion  18  along the upper edge on the upper side of the outer surface, and a guide shaft part  19  is formed on the distal end side thereof. The concave portion  18  spreads into a circular shape at the periphery of the guide shaft part  19 . At the lower side of each flat plate  12 , a slit  20  of a substantially L-shape is formed upward from the lower edge and then towards the distal end side, thereby forming an elastic tongue strip  21 . Engagement projections  22  are formed on the inner surface of the distal end side of the elastic tongue strip  21  and on the inner surface near the proximal part. The engagement projection  22  engages with the through hole  10   a  formed in the base  10  of the switch  1 .  
         [0039]     The spring holder  14  is made of a synthetic resin material similar to the housing  2 , as shown in  FIG. 2 , and is configured by a tubular part  23  having the upper surface opened and a projecting part  24  extending downward from the central part of the lower surface of the tubular part  23 . A projection  23   a  is formed at the central part of the bottom surface of the tubular part  23 . A coil spring  25  is arranged in the tubular part  23 . The projection  23   a  guides the coil spring  25  at the inner peripheral side of the lower end; however, the inner peripheral surface of the tubular part  23  may guide the coil spring  25  at the outer peripheral side, or the coil spring  25  may be sandwiched by both. In the former case, the projection  23   a  is not necessarily required. The projection  24  is inserted through the through hole  13   c  formed in the concave part  13   b  of the housing main body  11 , and projects from the lower surface.  
         [0040]     The drive lever  3  is formed by press working a metal plate material such as stainless steel, and has a bearing part  26  formed on one end and an engagement pawl part  27  formed on the other end, as shown in  FIG. 2 . The bearing part  26  has a circular shape and is formed with a through hole  26   a  at the center. The guide shaft part  19  formed in the flat plate  12  of the housing  2  is inserted into the through hole  26   a  so as to be supported in a freely rotating manner. The engagement pawl part  27  extends downward from both sides and the distal end forms an engagement pawl  27   a  of bent hook shape. The engagement pawl  27   a  engages with the collar part  13   a  of the housing main body  11  to limit the turning range of the drive lever  3 . An intermediate part  28  connecting the bearing part  26  and the engagement pawl part  27  is formed to have a width narrower than both ends. Thus, the weight is lighter overall, and the bending work of the bearing part  26  and the engagement pawl part  27  at both ends is facilitated. A projection  28   a  is formed by press working at the distal end side of the intermediate part  28 . The upper end of the coil spring  25  is guided by the projection  28   a , and the biasing force of the coil spring  25  acts on the lower surface of the intermediate part  28 .  
         [0041]     The adjustment dial  4  is made of a synthetic resin material similar to the housing  2 , has a disc shape and formed with a tubular part  29  at the center, as shown in  FIGS. 7 and 8 , which is inserted with the supporting shaft  16  of the housing main body  11 . A grip part  30  is formed on the lower surface of the adjustment dial  4  downward towards a position shifted from the center (eccentric position). The adjustment dial  4  can be rotated by way of the grip part  30 . The upper surface of the adjustment dial  4  includes a rotation regulating part  31  on the side corresponding to the grip part  30  and a load adjusting part  32  on the opposite side.  
         [0042]     At the rotation regulating part  31 , the stopper part  15  of the housing main body  11  is positioned, and the rotation regulating part  31  includes two contacting parts  31   a ,  31   b  to which the stopper part  15  contacts when the adjustment dial  4  is forward reverse rotated. Each contacting part  31   a ,  31   b  is in a positional relationship of a predetermined angle (150° herein) in the circumferential direction. One contacting part  31   a  is configured by an end face (end face extending in the radial direction) in the circumferential direction of a supporting board  33  at the highest position. The other contacting part  31   b  is configured by one of the side faces (contacting surfaces) of a projection formed in the radial direction adjacent to the supporting board  33  at the lowest position. A recess is formed in the up-and-down direction at the other side face of the projection.  
         [0043]     The load adjusting part  32  is configured by a plurality of supporting boards  33  formed in a staircase pattern in the circumferential direction. An engagement concave part  33   a  is formed in each supporting board  33 , so that the projection  24  of the spring holder  14  is detachably engaged with the engagement concave part  33   a . Each engagement concave part  33   a  is formed in a track shape extending in the radial direction. Here, the height from the lowest position to the highest position of the supporting board  33  is 1.5 mm, and the number thereof is eight. A gap is formed between the load adjusting part  32  and the tubular part  29 .  
         [0044]     The method of assembling the switch device SW of the above configuration will be described below.  
         [0045]     First, the housing  2  is attached to the switch  1 . In attaching the housing  2 , the engagement projection  22  is engaged with the through hole  10   a  of the switch  1  while the flat plate parts  12  are elastically deformed to be moved away from each other. In addition to the formation of the concave portion  18  in the flat plate part  12  to alleviate the entire rigidity, the elastic tongue strip  21  is formed by the slit  20 , and thus not only the engagement projection  22  on the free end side of the flat plate part  12  but also the engagement projection  22  on the free end side of the elastic tongue strip  21  are smoothly engaged with the through holes  10   a  of the switch  1 .  
         [0046]     Next, the spring holder  14  is arranged in the concave part of the housing  2 , and the coil spring  25  is arranged in the tubular part  23  of the spring holder  14 . The coil spring  25  has the outer peripheral side thereof guided by the inner peripheral surface of the tubular part  23 . The drive lever  3  is attached to the housing  2 . The drive lever  3  is turnably attached to the housing  2  by engaging the guide shaft part  19  formed in the concave portion  18  of the housing  2  with the through hole  26   a  while elastically deforming the bearing parts  26  in the direction of moving away. The engagement pawl part  27  of the drive lever  3  is then engaged with the collar part of the housing  2 . Thus, the drive lever  3  can be turned at an angle within a predetermined range with respect to the housing  2 . Since the engagement pawl part  27  is formed in the drive lever  3 , the dimension in the height direction at the relevant portion is suppressed in comparison with the case of adopting the configuration of engaging the free end of the drive lever  3  to the housing  2 .  
         [0047]     Furthermore, the adjustment dial  4  is attached to the lower surface of the housing main body  11 . The adjustment dial  4  is attached by inserting the supporting shaft  16  of the housing main body  11  to the tubular part  29 , and engaging the fixed ring  17  with the annular groove  16   a  formed at the distal end of the supporting shaft  16 . The stopper part  15  is positioned in the rotation regulating part  31  at this point. The projection  24  of the spring holder  14  is engaged with the engagement concave part  33   a  of one of the supporting boards  33  of the load adjusting part  32 . The coil spring  25  held at the spring holder  14  is pressure contacted to the lower surface of the distal end side of the drive lever  3 , whereby the drive lever  3  is turned to the position (initial position) that is spaced apart from the button  6  of the switch  1 .  
         [0048]     In the switch device SW assembled in this manner, the biasing force of the coil spring  25  acting on the operation lever can be adjusted by rotating the adjustment dial  4  by way of the grip part  30 . That is, when the adjustment dial  4  is rotated, the projection  24  of the spring holder  14  engaged in a pressure contacting state with the engagement concave part  33   a  of a certain supporting board  33  sequentially changes the engagement position to the engagement concave part  33   a  of the adjacent supporting board  33 . The spacing between the spring holder  14  and the drive lever  3  changes, since the supporting board  33  is formed in a staircase pattern. That is, the initial length of the coil spring  25  is changed, and the biasing force on the drive lever  3  is adjusted. The projection  24  of the spring holder  14  pressure contacts the engagement concave part  33   a  of the adjustment dial  4 , and the stopper part  15  of the housing  2  contacts the adjustment dial  4  at a position substantially point symmetric with the center of rotation at the center. Therefore, balance is maintained, and the adjustment dial  4  is smoothly rotated.  
         [0049]     The above assembly method is merely an example, and the housing  2  may be attached to the switch  1  after the spring holder  14 , the coil spring  25 , and the adjustment dial  4  are attached to the housing  2 .  
         [0050]     The operation of the switch device SW having the above configuration will now be described.  
         [0051]     The switch device SW is mounted on a printed substrate P, as shown in  FIGS. 9 and 10 , and for example, is incorporated in a mouse of a computer (not shown) and used for detecting click on the mouse. In mounting the switch device SW to the printed substrate P, the terminals projecting from the base  10  of the switch  1  are respectively inserted to terminal holes Ph formed in the printed substrate P that is mounted with various electronic components, and fixed through soldering.  
         [0052]     A user checks the repulsive force due to the biasing force of the coil spring  25  by clicking the mouse, and rotates the adjustment dial  4  by way of the grip part  30  so as to obtain an appropriate click feeling that meets his/her preference. The biasing force of the coil spring  25  is adjustable at multi-levels by the plurality of supporting boards  33  formed on the adjustment dial  4 . Therefore, the biasing force can be adjusted so as to reliably obtain a particular click feeling desired by the user.  
       Second Embodiment  
       [0053]     FIGS.  11  to  13  show a switch device SW according to a second embodiment. The components of the switch device SW are substantially the same as those in the first embodiment, but differ in that a slider  40  is used in place of the adjustment dial  4 .  
         [0054]     That is, the slider  40  is arranged on the printed substrate P to which the switch  1  is mounted, and is configured by a slider main body  41  and a slider supporting member  42 .  
         [0055]     The slider main body  41  has an inclined surface  41   a  which gradually goes upwards towards one end side, on the upper surface, and a substantially L-shaped elastic engagement strip  43  is formed on both sides of the slider main body  41 . Each elastic engagement strip  43  is elastically deformable to move closer to or away from the side surface of the slider main body  41  and is formed with an engagement projection  43   a  at the distal end portion. A guide part  44  extending in the longitudinal direction is formed at the center part of the bottom surface of the slider main body  41 .  
         [0056]     The slider supporting member  42  has a flat plate shape to be attached to the bottom surface side of the printed substrate P. A guide hole  45  for guiding in a reciprocating manner the guide part  44  of the slider main body  41  is formed at the center part of the slider supporting member  42 . An engagement receiving part  46  in which a plurality of engagement concave parts  46   a , with which the engagement projection  22  of the elastic engagement strip  43  engages and disengages, is formed continuously in a wave form is formed at predetermined intervals on both sides in the upper surface of the slider supporting member  42 .  
         [0057]     The slider  40  of the above configuration is fixed at the bottom surface of the printed substrate P through screwing etc. after mounting the slider main body  41  on the slider supporting member  42 , and engaging the engagement projection  43   a  with the engagement concave part  46   a  while elastically deforming the elastic engagement strip  43  on both sides inwards. In this state, the inclined surface  41   a  of the slider main body  41  projects upwards through an opening (not shown) formed in the printed substrate P, so that the projection  24  of the spring holder  14  is pressure contacted thereto. Therefore, when the slider main body  41  is slid with respect to the slider supporting member  42 , the engagement position of the engagement projection  43   a  with respect to the engagement concave part  46   a  changes and the position of the inclined surface  41   a  to which the projection  24  contacts also changes. The spacing to the contacting position with the drive lever  3 , in which the coil spring  25  is interposed, thus can be changed. Consequently, the biasing force of the coil spring  25  is changed and the force required for the operation of the drive lever  3  is adjusted.  
       Third Embodiment  
       [0058]      FIG. 14  shows a switch device SW according to a third embodiment. In the switch device SW, a supporting plate  50  arranged at the bottom surface of the housing  2  is used in place of the adjustment dial  4  and the slider  40 .  
         [0059]     The supporting plate  50  is made of a plate spring and has one end side fixed to the bottom surface of the housing  2  with a screw etc., and has the upper surface on the other end side pressure contacted by one end of the coil spring  25 . The free end side of the supporting plate  50  may be deformed by bending etc., as shown with a chain double-dashed line in the figure as necessary, or supported by other members (not shown) to adjust the biasing force of the coil spring  25 .