Abstract:
A rocker switch for one two-stage actuating stroke, especially in the form of a window control switch for a motor vehicle. The rocker switch includes a rocker button which is mounted in a housing. An actuating plate for acting on switching contacts that are connected to terminal contacts is associated with said rocker button. A switching contact is allocated to the actuating stroke of the first stage in each direction, respectively and a common switching contact is allocated to the actuating stroke of the second stage in each direction, respectively.

Description:
TECHNICAL FIELD 
     The invention generally relates to electrical switches, and more particularly relates to rocker switches having a two-stage actuating stroke. 
     BACKGROUND OF THE INVENTION 
     DE 195 37 296 A1 details a rocker switch device for a two-stage actuating stroke that is part of an actuating unit for electric window openers of a motor vehicle and comprises a pair of actuating plates underneath a longitudinal middle line of a rocker button. The actuating plates are coupled by elastic connecting arms and form an actuating member in this manner. Each actuating plate loads two pressure switches formed by a switching mat with hollow projections and with contact pieces arranged therein and by a base plate with fixed contact pieces associated with the moveable contact pieces. When the rocker button is actuated it pivots about carrier axle ends of a housing so that the actuated side of the rocker button moves down. This downwardly directed movement is transmitted via the associated actuating plate to the left and right projections, arranged underneath this plate, of the switching mat. The projections are arranged in such a manner that as a result of the differently acting torques at first the left projection is deformed and a circuit is closed by the contact of the contact pieces arranged here and after a further downward movement of the rocker button the right projection is also pressed downward by the actuating plate and another circuit is closed. After the rocker button is released it is automatically returned, which interrupts the closed circuit. The rocker switch device accordingly comprises a plurality of contact pieces and actuating plates that bring about the appropriate switching functions for controlling the electric window opener, which necessitates an extremely complex design of the rocker switch device. 
     Furthermore, a multi-stage rocker switch is known from DE 196 00 657 C1 that consists substantially of a rocker button pivotably supported on the housing and of four push rods received by a conductor plate, which rods are arranged beneath the rocker button. The conductor plate is arranged inside the housing parallel to a conductor plate. Each push rod acts with a dome of a switch mat that receives a contact piece that makes contact with a fixed contact piece upon a loading of the dome by the associated push rod after the dome is bent in and closes a current path. Each two adjacent domes have a different stability, which has, as a consequence, a bending in upon a different action of force. The two push rods arranged in the area of each front side of the rocker button and loading the corresponding, adjacent domes are actuated by an associated appendage of the rocker button which appendage acts on an intermediate element supported in the conductor plate in such a manner that this element can pivot and also shift vertically. To this end the intermediate element comprises horizontal guide pins resting in corresponding grooves of the conductor plate. The intermediate element is designed as a two-arm lever and a push rod is associated with each lever arm. When the rocker button is actuated, the associated intermediate element is loaded via the appendage of the rocker button with a pressure force opposed by the different pressure forces of the domes. The dome associated with an actuating stroke of a first state bends in, while the intermediate element is shifted vertically as well as pivoted, since the associated lever arm constantly rests on the corresponding push rod on account of the acting forces. Upon an actuating stroke of a second stage the dome adjacent to the first dome also bends in, while the two lever arms are located in a horizontal position and the intermediate element is shifted vertically in the direction of the domes by a further path stretch. The rocker switch is disadvantageous in as far as a very complex switching mechanism is provided for realizing a two-stage actuating stroke. 
     In addition, EP 0 604 837 A1 teaches a hand-actuated control switch for a raising device with a rocker switch for a two-stage actuating stroke in which a rocker button is pivotably supported in a front plate of a housing. The rocker button is associated with an actuating device comprising two levers for loading switching contacts. The switching contacts are arranged in a series on a conductor plate. The actuating stroke of the first stage is associated in each direction with the particular outer switching contact and the actuating stroke of the second stage is associated in each direction with the central switching contact. Each lever of the actuating device loads one of the outer switching contacts and both levers actuate the central switching contact. 
     The invention has the problem of creating a rocker switch of the initially cited type that is distinguished by a compact design with the lowest possible number of structural components and with a reliable operation. 
     The invention solves this problem in that the operating stroke of the first stage is associated in each direction with a switching contact and the actuating stroke of the second stage is associated in each direction with a joint switching contact. 
     Based on these measures, the rocker switch comprises only three switching contacts for one two-stage actuating stroke, which results in a compact design and a relatively low number of structural components. The particular switching contact of the actuating stroke of the first stage furnishes a signal about the direction in which the rocker button was loaded and initiates a first switch operation. The actuation of the switching contact associated with the actuating stroke of the second stage brings about another signaling that initiates a second switch operation associated with the first switch operation. For example, the particular switching contact associated with the actuating stroke of the first stage initiates an up or down movement of an associated motor vehicle window that is ended after the rocker button has been released. The joint switching contact for the actuating stroke of the second stage controls a movement of the corresponding motor vehicle window up to its end position, the direction of which is given by the particular first-actuated switching contact. A reliable operation of the rocker switch is assured on account of connection of the second switch operation to the first switch operation. The coupling of the operation of the particular first-loaded switching contact to the operation of the joint switching contact can be realized electrically or via an appropriate control of on-board electronic components. 
     According to an advantageous embodiment of the invention the three switching contacts are arranged in the form of an equilateral triangle. The switching contacts of the actuating stroke of the first stage are each arranged at a corner point of the base and the switching contact of the actuating stroke of the second stage is arranged at the apex of the triangle. It is advantageous if the base of the equilateral triangle runs parallel to a side wall of the housing and its apex is located under a shaft of the rocker button of the opposite side wall. This arrangement of the switching contacts results in a compact design of the rocker switch and a tactile determination of the first and second stages of the actuating stroke. The switching contacts associated with the first stage of the actuating stroke are arranged at a relatively large spacing from the shaft of the rocker button, so that an appropriate lever arm is available to load them, for which reason the actuation of these switching contacts requires a lesser force in comparison to the actuation of the switching contact arranged on the apex, for which no lever arm is available to load it. 
     The actuating plate is advantageously supported by way of associated studs on the switching contacts under lateral play relative to the housing. The actuating plate and the studs form a unit in order to transfer the motion of the rocker button on the appropriate switching contact or contacts. Furthermore, no support for the freely movable actuating plate is provided. 
     In order to impart an appropriate stability to the actuating plate and assure a pivoting motion of the actuating plate as a function of the actuating direction of the rocker button, the actuating plate is provided in a purposeful manner with a crosspiece offset off-center to the longitudinal axis of the switch in the direction of the switching contact located at the triangle apex. An appendage of the rocker button rests on this crosspiece on each of the two sides of the rocker button shaft. As a result of the off-center arrangement of the crosspiece the actuating plate pivots upon an introduction of force on one side via the associated appendage about the corresponding side of the triangle in which side the switching contacts are arranged. Furthermore, the actuating plate is held between the switching contacts and the appendages of the rocker button so that no shifting of the actuating plate due to vibration occurs. 
     The crosspiece of the actuating plate preferably displays a semicircular clear space for the shaft of the rocker button. The clear space makes possible the pivoting movement of the actuating plate, that does not take place perpendicularly to the shaft but rather about the corresponding side of the triangle, for which reason the actuating plate readily rotates in this instance. 
     The rocker button advantageously comprises two opposing support lugs for receiving the shaft. Furthermore, the shaft advantageously engages in support bores in the side walls of the housing, with a disk arranged between the side wall and the support lug of the rocker button in each instance, which assures a reliable support of the rocker button. The disk arranged between the particular side wall of the housing and the corresponding support lug of the rocker button reduces the friction between these components when the rocker button is pivoted. 
     In an alternative embodiment of the invention the shaft is designed as axle ends formed on the opposite support lugs of the rocker button which axle ends engage in corresponding support bores in the side walls of the housing. This embodiment creates a reliable support of the rocker button in the housing with a relatively low number of individual parts to be mounted. 
     According to an advantageous further development of the concept of the invention the switching contacts are designed as snap disks that cooperate with contact paths of a punched grid set in the housing bottom. In an alternative embodiment the switch contacts are designed as snap disks that cooperate with contact paths of a conductor plate lying on the bottom of the housing. The snap disks have a pre-tension that assures the return movement of the rocker button. The punched grid is injected during the injection-molding process for manufacturing the housing into its bottom. 
     Each snap disk is preferably held via two lock bolts on the sides of the housing. The mounting of the snap disks takes place without great expenditure by simply inserting the snap disks between the lock bolts, which assure a sufficient fixing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a longitudinal section through a rocker switch in accordance with the invention. 
     FIG. 2 shows a section through the view of FIG. 1 along line II—II. 
     FIG. 3 shows a section through the view of FIG. 1 along line III—III. 
     FIG. 4 shows an exploded view of the rocker switch of FIG. 1 in the direction of arrow IV. 
     FIG. 5 shows an exploded view of the rocker switch of FIG. 1 in the direction of arrow V. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The rocker switch comprises rocker button  2  supported in housing  1  and with support lugs  3  formed on opposing longitudinal sides for receiving shaft  4 . In addition, rocker button  2  comprises appendages  5 , 6  arranged on both sides of shaft  4 . Shaft  4  is inserted in corresponding support bores  7  in side walls  8  of housing  1 . Disk  9  is provided between support lugs  3  of rocker button  2  and the associated side wall  8  to reduce the friction. Appendages  5 , 6  of rocker button  2  rest on crosspiece  10  of actuating plate  11 . This crosspiece  10  is offset off-center to longitudinal switch axis  12  (see FIG. 2) and comprises semicircular clear space  13  for shaft  4  of rocker button  2 . Actuating plate  11  is inserted with lateral play into housing  1  and is supported via associated studs  14 ,  15 ,  16  on switching contacts  17 ,  18 ,  19  that are designed as snap disks and arranged in the form of equilateral triangle  20 . Base  21  of the equilateral triangle with the particular switching contacts  17 ,  19  on the end side runs parallel to the corresponding side wall  8  of housing  1 . Switching contact  18  on apex  22  of triangle  20  is associated under shaft  4  of rocker button  2  with the opposite side wall  8  (see FIG.  3 ). 
     Each switching contact  17 ,  18 ,  19  is held by opposing recesses  23  that receive corresponding lock bolts  24 , wherein the lock bolts  24  are arranged in bottom  25  of housing  1 . Conductor plate  26  is located on bottom  25  and comprises contact paths associated with switching contacts  17 ,  18 ,  19 , the connection contacts  27  of which paths extend to the outside through bottom  25  of housing  1 . 
     When rocker button  2  is pivoted in the direction of arrow  28  by one actuating stroke of first stage  29 , appendage  6  of rocker button  2  acts on crosspiece  10  of actuating plate  11 . Since this crosspiece is arranged offset to longitudinal switch axis  12  in the direction of apex  22  of triangle  20  and studs  14 ,  15 , and  16  of actuating plate  11  rest on associated switching contacts  17 ,  18 ,  19 , actuating plate  11  pivots about leg  30  of triangle  20 . As a result of the acting lever conditions, stud  14  associated with switching contact  17  presses the latter down so that a corresponding, first electric circuit of conductor plate  26  is closed. The first circuit, closed by switching contact  17 , brings about the controlling of a window opener motor that opens an associated motor vehicle window. After rocker button  2  is released, this circuit is opened and the motor vehicle window remains in the position reached. Rocker button  2  is returned into its initial position by the return movement of switching contact  17 . 
     The pivoting of rocker button  2  in the direction of arrow  28  by an actuating stroke of second stage  31  brings about the previously explained pivot movement of actuating plate  11  about leg  30  of triangle  20  and the pressing down of switching contact  17  on corner point  32  of base  21  of triangle  20  as well as the closing of the first circuit, with which the opening movement of the motor vehicle window is associated. The actuation of switching contact  18  on apex  22  of triangle  20  subsequently takes place by stud  15  of actuating plate  11 . The actuation of switching contact  18  requires an elevated expenditure of force in contrast to the actuation of switching contact  17  on account of the acting lever conditions. The closing of a second circuit by switching contact  18  also brings about a controlling of the window opener motor, which motor moves the motor vehicle window either rapidly and/or into an open end position. After rocker button  2  is released, it returns to its initial position due to the return movements of switching contacts  17 ,  18  and the motor vehicle window either remains in the position reached or moves into its open end position. 
     If rocker button  2  is pivoted in the direction of arrow  33  by one actuating stroke of first stage  29 , stud  5  loads actuating plate  11 , which causes it to pivot about leg  34  of triangle  20 . Stud  16  of actuating plate  11  presses associated switching contact  19  onto conductor plate  26 , as a result of which a circuit is closed that controls the corresponding window opener motor, that brings about a closing movement of the motor vehicle window. The release of rocker button  2  effects an opening of the circuit and, associated with this, the motor vehicle window remains in the position reached. The return of rocker button  2  takes place by the return movement of switching contact  19 , that pivots actuating plate  11  connected to rocker button  2  via appendage  5  into a position parallel to bottom  25  of housing  1 . 
     The pivoting of rocker button  2  in the direction of arrow  33  by one actuating stroke of second stage  31  has as a consequence the previously explained pivoting movement of actuating plate  11  about leg  34  of triangle  20  and the pressing down of switching contact  19  on corner point  35  of base  21  of triangle  20  as well as the associated closing movement of the motor vehicle window. After switching contact  19  has reached its end position on conductor plate  26 , switching contact  18  is loaded by corresponding stud  15  of actuating plate  11  and the second circuit on conductor plate  26  is closed. As a result thereof, the controlled window opener motor moves the motor vehicle window either rapidly and/or into a closed end position. The release of rocker button  2  causes the motor vehicle window to either remain in the position reached or to move into its closed end position. Furthermore, rocker button  2  returns to its initial position due to the return movements of switching contacts  18 ,  19 . 
     The cooperation of switching contacts  17 ,  19  of the particular first stage  29 , arranged in corner points  32 ,  35  of triangle  20 , with switching contact  18  assigned to apex  22  of triangle  20  is realized by an appropriate electric circuit or by the control of on-board electronic circuitry. The on-board electronic circuitry stores directional information in the particular first stage, initiated by switching contact  17  or switching contact  19  for opening or closing the motor vehicle window, and, if necessary, after the particular second stage  31  has been reached, assigns further information effected by switching contact  18  to the directional information. This information of the particular second stage  31  of the actuating stroke causes the motor vehicle window to execute a rapid movement and/or to move into one of the end positions. The movement either opens or closes the motor vehicle window as a function of the previously stored information. 
     List of Reference Numerals 
       1  housing 
       2  rocker button 
       3  support lug 
       4  shaft 
       5  appendage 
       6  appendage 
       7  support bore 
       8  side wall 
       9  disk 
       10  crosspiece 
       11  actuating plate 
       12  longitudinal switch axis 
       13  clear space 
       14  stud 
       15  stud 
       16  stud 
       17  switching contact 
       18  switching contact 
       19  switching contact 
       20  triangle 
       21  base 
       22  apex 
       23  recess 
       24  lock bolt 
       25  bottom 
       26  conductor plate 
       27  connection contact 
       28  arrow 
       29  first stage 
       30  leg 
       31  second stage 
       32  corner point 
       33  arrow 
       34  leg 
       35  corner point