Patent Publication Number: US-2009229959-A1

Title: Dual mode switch

Description:
RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Patent Application Ser. No. 60/819,516, filed on Jul. 7, 2006, incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to electrical switches, and in particular to dual mode electrical switches. 
     BACKGROUND OF THE INVENTION 
     Many switches that are operable for making and breaking electrical circuits are known. Such switches are operated by a user to break/make electrical contacts for turning on or turning off electrical module(s) connected to the switches. One example includes switches for electrical heating and cooling in vehicles. However, there is a need for a dual mode switch that includes both normally-open and normally-closed contacts which can be used to operate electrical devices in a vehicle such as for heating and cooling a cup holder. 
     BRIEF SUMMARY OF THE INVENTION 
     A switching apparatus has a normally-open switching device comprising first and second normally-open switches and a normally-closed switching device comprising first and second normally-closed switches. The switching apparatus also has an actuator operable in conjunction with the switching devices such that: (a) in a neutral actuator mode the first and second normally-open switches remain open, and the first and second normally-closed switches remain closed, (b) in a first operation mode the actuator operates on the first normally-closed switch and the first normally-open switch, and (c) in a second operation mode the actuator operates on the second normally-closed switch and the second normally-open switch. 
     These and other features, aspects and advantages of the present invention will become understood with reference to the following description, appended claims and accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a switching apparatus with its cover in place, according to an embodiment of the present invention. 
         FIG. 2  shows a perspective view of the switching apparatus of  FIG. 1  with the cover removed. 
         FIG. 3  shows another perspective view of the switching apparatus of  FIG. 1  with the cover removed. 
         FIG. 4  shows a perspective view of the switching apparatus of  FIG. 1  with the cover and bezel removed. 
         FIG. 5  shows a perspective view of the switching apparatus of  FIG. 1  with the cover and bezel removed. 
         FIG. 6  shows another perspective view of the switching apparatus of  FIG. 1  with the cover, bezel and rocker removed. 
         FIG. 7  shows a perspective view of a switching apparatus with partially pivoted rocker, according to an embodiment of the present invention. 
         FIG. 8  shows another perspective view of the switching apparatus of  FIG. 7 . 
         FIG. 9  shows a side view of the switching apparatus of  FIG. 7 . 
         FIG. 10  shows an end view of the switching apparatus of  FIG. 7 . 
         FIG. 11  shows a perspective view of a switching apparatus with fully pivoted rocker, according to an embodiment of the present invention. 
         FIG. 12  shows another perspective view of the switching apparatus of  FIG. 11 . 
         FIG. 13  shows a side view of the switching apparatus of  FIG. 12 . 
         FIG. 14  shows an end view of the switching apparatus of  FIG. 13 . 
         FIG. 15  shows a perspective view of a switching apparatus with un-pivoted rocker, according to an embodiment of the present invention. 
         FIG. 16  shows another perspective view of the switching apparatus of  FIG. 15 . 
         FIG. 17  shows a side view of the switching apparatus of  FIG. 15 . 
         FIG. 18  shows an end view of the switching apparatus of  FIG. 15 . 
         FIG. 19  shows a perspective view of the top surface of the keypad of the switching device of  FIG. 7 . 
         FIG. 20  shows a perspective view of the bottom surface of the keypad of the switching device of  FIG. 7 . 
         FIG. 21  shows a perspective view of the bottom surface of the circuit board of the switching apparatus of  FIG. 15 . 
         FIG. 22  shows another perspective view of the bottom surface of the circuit board of the switching apparatus of  FIG. 15 . 
         FIG. 23  shows another perspective view of the bottom surface of the circuit board of the switching apparatus of  FIG. 15 . 
         FIG. 24  shows a perspective view of the top surface of the circuit board of the switching apparatus of  FIG. 15 . 
         FIG. 25  shows another perspective view of the top surface of the circuit board of the switching apparatus of  FIG. 15 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In one embodiment the present invention provides a dual mode switch that in one example application can be used to operate electrical devices in a vehicle. The dual mode switch provides both normally-open and normally-closed positions. Referring to the example embodiment shown in  FIGS. 1-4 , the dual switch  10  includes a cover  12 , and a bezel  16  (although in the following description the element  12  is called a “cover” and the element  16  is called a “bezel”, the terms cover and bezel for the elements  12  and  16 , respectively, can be interchanged such that the element  12  is called the bezel  12  and the element  16  is called the cover  16 ). The switch  10  further includes an actuator comprising a rocker  14 , a circuit board (PCB)  18 , a normally-closed switching device comprising an elongated contact strip  20 , and a normally-open switching device comprising a keypad  22 .  FIG. 1  shows the switch  10  with the cover  12 . 
       FIGS. 2 and 3  show perspective views of the switch  10  with the cover  12  removed, illustrating that the bezel  16  supports the cover  12 , and that the bezel  16  also supports the rocker  14  on hinges  24  on either side, such that the rocker  14  pivots on the hinges  24 . The bezel  16  further supports the PCB  18 . The PCB  18  is a dual-sided circuit board with conductive traces on opposing surfaces/sides. 
       FIG. 4  shows another perspective view of the switching apparatus of  FIG. 1  with the cover  12  and bezel  16  removed.  FIG. 5  shows the bezel  16  removed, further illustrating that the top surface of the PCB  18  supports the keypad  22 , and that the elongated contact  20  is mechanically connected to the bottom surface of the PCB  18  at the center  26  ( FIG. 21 ) of the contact  20 . 
       FIG. 6  shows the rocker  14  removed, illustrating that the elongate keypad  22  is supported by the top surface of the PCB  18 , whereby the PCB  18  is sandwiched between the keypad  22  and the contact  20 . The contact strip  20  ( FIGS. 21-22 ) has a generally springy characteristic, and as noted, is connected at its center  26  (between the two L-shaped ends  20 A,  20 B), to the bottom surface of the PCB  18 . As such, the springy nature of the contact  20  causes at least protrusions  28 A,  28 B of the contact  20 , on either side of center  26 , to be normally urged against, and in contact with, the bottom surface of the PCB  18 . 
       FIGS. 7 and 8  show perspective views of the switch  10  wherein the rocker  14  is partially pivoted to one side on the hinge  24  such that a rocker protrusion (rib)  30 A presses against an L-shaped end  20 A of the contact  20 .  FIG. 9  shows a side view of the switch  10  of  FIGS. 7-8 , and  FIG. 10  shows an end view of the switch  10  in  FIGS. 7 and 8 . 
     As shown in  FIGS. 7-10 , when the rocker  14  is partially pivoted on the hinge  24  to one side, such that a rocker protrusion  30 A presses against an L-shaped end  20 A of the contact  20 , the protrusion  28 A of contact  20  proximate that L-shaped end  20 A is pushed away, and separated from, the bottom surface of the PCB  18 . Said protrusion  28 A of the contact  20  remains separated from the PCB  18  so long as the rocker protrusion  30 A pushes against that L-shaped end  20 A of the contact  20 . A corresponding rocker protrusion (rib)  30 B is moved away from the L-shaped end  20 B of the contact  20 . 
       FIG. 6  further shows that at its distal ends, the elongate keypad  22  includes retainer  25 A,  25 B for domes  23 A,  23 B having tops  27 A,  27 B, respectively. Apertures  29 A and  29 B on the keypad  22  ( FIG. 20 ) and holes  33 A,  33 B on the PCB  18  ( FIG. 21 ), respectively, are essentially aligned when the keypad  22  is placed on the PCB  18  ( FIG. 6 ) such that posts  35 A,  35 B ( FIG. 6 ) from the bezel  16  pass through the holes  33 A,  33 B of the PCB  18  and the apertures  29 A and  29 B of the keypad  22 , respectively, to retain the PCB  18  and the keypad  22  on the bezel  16 . Hooks  37 A,  37 B ( FIG. 3 ) snap over the edges of the PCB  18  and hold it on the bezel  16 . The keypad  22  keeps the rocker  14  stabilized when the rocker is not pivoted. The keypad  22 , and in particular the domes  23 A,  23 B, are flexible. Each dome  23 A,  23 B is compressible, such that, as shown in  FIGS. 8-9 , when the rocker  14  is partially pivoted to one side, another rocker protrusion (plunger)  32 A presses against a top  27 A ( FIG. 5 ) of the keypad  22 , thereby partially compressing (collapsing) the top  27 A into the dome  23 A. As such, in  FIGS. 8-9 , the partially compressed top  27 A is partially visible compared to the uncompressed top  27 B. A corresponding rocker protrusion (plunger)  32 B is moved further away from the top  27 B. 
     As such, when the rocker  14  is not pivoted (e.g.,  FIGS. 1-4 ), neither the top  27 A,  27 B is compressed into corresponding domes  23 A,  23 B, of the keypad  22 . Further, the protrusions  28 A,  28 B of contact  20  (on either side of the center  26 ) remain urged against the bottom surface of the PCB  18 . When the rocker  14  is partially pivoted to one side (e.g.,  FIGS. 8-9 ), the top  27 A of the keypad  22  is partially pushed down, partially compressing the corresponding dome  23 A. Further, the protrusion  28 A of the contact  20  is pushed away (separated) from the bottom surface of the PCB  18  via the compressing action of rocker protrusion  30 A on the L-shaped end  20 A of the contact  20 . 
       FIGS. 11-14  show that the rocker  14  is fully pivoted to one side.  FIGS. 11 and 12  show perspective views of the switch  10  with the rocker  14  fully pivoted to one side.  FIG. 13  shows a side view of the switch  10  with the rocker  14  fully pivoted to one side.  FIG. 14  shows an end view of the switch  10  with the rocker  14  fully pivoted to one side. When the rocker  14  is fully pivoted, the rocker protrusion  32 A further pushes the top  27 A, compressing it essentially completely into the corresponding dome  23 A of the keypad  22 , such that the compressed top  27 A is no longer visible in  FIGS. 11-14 . The uncompressed top  27 B remains visible however. Further, the protrusion  28 A of the contact  20  is further pushed away (separated) from the bottom surface of the PCB  18 . 
       FIGS. 15-18  show the rocker  14  returned from the fully pivoted position shown in  FIGS. 11-14 , back to the normal position where the rocker  14  is not pivoted to either side (as in  FIGS. 7-10 ). Specifically,  FIGS. 15 and 16  show perspective views of the switch  10  with the rocker  14  not pivoted. As such neither domes  23 A,  23 B are uncompressed, and both protrusions  28 A,  28 B of the contact  20  are again urged against the bottom surface of the PCB  18 .  FIG. 17  shows a side view of the switch  10  with the rocker  14  not pivoted, and  FIG. 18  shows an end view of the switch  10  with the rocker  14  not pivoted. 
       FIG. 19  illustrating a perspective view of the top of the keypad  22  alone, showing a key switch at each end of the keypad  22 , wherein a first key switch  22 A comprises the retainer  25 A, the dome  23 A and the top  27 A. A second key switch  22 B comprises the retainer  25 B, the dome  23 B and the top  27 B.  FIG. 20  shows a perspective view of the bottom of the keypad  22 , further comprising conductive disks  34 A and  34 B disposed inside the tops  27 A and  27 B, respectively. 
       FIG. 21  shows a perspective view of the bottom surface of the PCB  18 . Conductive trace  36  runs between nodes  36 A,  36 B, conductive trace  38  runs between nodes  38 A,  38 B, and conductive trace  40  runs between nodes  40 A,  40 B. Further, the center  26  of the contact  20  is connected to the node  38 B.  FIG. 22  shows another perspective view of the bottom surface of the PCB  18 .  FIG. 23  shows another perspective view of the PCB  18  wherein a contact pin  36 C is connected to node  36 A, a contact pin  38 C is connected to node  38 A and a contact pin  40 C is connected to node  40 A. 
     If the rocker  14  is not pivoted (e.g.,  FIGS. 15-18 ), the protrusion  28 A of the contact  20  is urged against, and electrically coupled to, the node  40 B, whereby the nodes  38 A and  40 A are electrically connected through a portion  21 A (contact switch  21 A) of the contact  20  between the center  26  and the protrusion  28 A (i.e., the contact switch  21 A is in a closed switch position). Similarly, if the rocker  14  is not pivoted, then the protrusion  28 B of the contact  20  is urged against, and electrically coupled to, the node  36 B, whereby the nodes  36 A and  38 A are electrically connected through a portion  21 B (contact switch  21 B) of the contact  20  between the center  26  and the protrusion  28 B (i.e., the contact switch  21 B is in a closed switch position). 
     When the rocker  14  is partially, or fully, pivoted to the side of the contact switch  21 A (e.g.,  FIGS. 7-10 ,  11 - 14 ), then the rocker protrusion  30 A presses against the L-shaped end  20 A of the contact  20 , such that the protrusion  28 A of contact  20  is pushed away, and separated from, the node  40 B, opening the contact switch  21 A. Similarly, when the rocker  14  is partially, or fully, pivoted to the side of the contact switch  21 B, then the rocker protrusion  30 B presses against the L-shaped end  20 B of the contact  20 , such that the protrusion  28 B of the contact  20  is pushed away, and separated from, the node  40 B, opening the contact switch  21 B. 
       FIG. 24  shows a perspective view of the upper surface of the PCB  18 , including traces  42 ,  44  and  46 . Trace  42  runs between nodes  42 A and  42 B. Trace  44  runs between nodes  44 A,  44 B and  38 A. Trace  46  runs between nodes  46 A and  46 B.  FIG. 8  shows another perspective view of the upper surface of the PCB  18 . 
     The keypad  22  is placed on the upper/top surface of the PCB  18  ( FIG. 6 ) such that the disk  34 A ( FIGS. 19-20 ) of the key switch  22 A is centered atop the nodes  44 A,  46 B ( FIGS. 24-25 ) on the top surface of the PCB  18  proximate the L-shaped end  20 A of the contact  20 . Similarly, the disk  34 B ( FIGS. 19-20 ) of the key switch  22 B is centered atop the nodes  42 B,  44 B ( FIGS. 24-25 ) on the top surface of the PCB  18  proximate the L-shaped end  20 B of the contact  20 . 
     When the rocker  14  is fully pivoted towards L-shaped end  20 A of contact  20  (e.g.,  FIGS. 11-14 ), the rocker protrusion  32 A pushes the top  27 A, compressing it essentially completely into the corresponding dome  23 A of the keypad  22 , such that the conductive disk  34 A under the top  27 A is urged against, and electrically coupled to, the nodes  44 A and  46 B on top surface of the PCB  18  ( FIG. 25 ). When the disk  34 A is electrically coupled to the nodes  44 A and  46 B, the key switch  22 A is considered closed, whereby the nodes  38 A and  46 A are electrically connected. When the rocker  14  is not fully pivoted towards L-shaped end  20 A, such that the conductive disk  34 A under the top  27 A is not electrically coupled to the nodes  44 A and  46 B; then the key switch  22 A is considered open. Since the rocker  14  is normally not pivoted at all, then the key switch  22 A is considered normally-open, and is closed only when the rocker  14  is fully pivoted towards L-shaped end  20 A of the contact  20 . 
     When the rocker  14  is fully pivoted towards L-shaped end  20 B of the contact  20 , the rocker protrusion  32 B pushes the top  27 B, compressing it essentially completely into the corresponding dome  23 B of the keypad  22 , such that the conductive disk  34 B under the top  27 B is urged against, and electrically coupled to, the nodes  42 B and  44 B on the top surface of the PCB  18 . When the disk  34 A is electrically coupled to the nodes  42 B and  44 B, the key switch  22 B is considered closed, whereby the nodes  38 A and  42 A are electrically connected. When the rocker  14  is not fully pivoted towards the L-shaped end  20 B, such that the conductive disk  34 B under the top  27 B is not electrically coupled to the nodes  42 B,  44 B, then the key switch  22 B is considered open. Since the rocker  14  is normally not pivoted at all, then the key switch  22 B is considered normally-open, and is closed only when the rocker  14  is fully pivoted towards L-shaped end  20 B of the contact  20 . 
     Similarly, since the rocker  14  is normally not pivoted at all, then the contact switches  21 A and  21 B are normally-closed. As such, contact switches  21 A,  21 B are normally-closed, and key switches  22 A,  22 B are normally-open. When the rocker  14  is partially pivoted towards the L-shaped end  20 A, then the normally-closed contact switch  21 A is opened, while the normally-open key switch  22 A remains open. When the rocker  14  is fully pivoted towards the L-shaped end  20 A, then the contact switch  21 A remains open while the key switch  22 A is closed. Throughout the pivoting of the rocker  14  toward the L-shaped end  20 A, the normally-closed contact switch  21 B and normally-open key switch  22 B, maintain their states without change. 
     When the rocker  14  is partially pivoted towards the L-shaped end  20 B, then the normally-closed contact switch  21 B is opened, while the normally-open key switch  22 B remains open. When the rocker  14  is fully pivoted towards the L-shaped end  20 B, then the contact switch  21 B remains open while the key switch  22 B is closed. Throughout the pivoting of the rocker  14  toward the L-shaped end  20 B, the normally-closed contact switch  21 A and the normally-open key switch  22 A, maintain their states without change. The bottom surface of the PCB  18  along with the contact  20  implement the normally-closed contact switches  21 A,  21 B, whereas the top surface of the PCB  18  along with the keypad  22  implement the normally-open key switches  22 A,  22 B. 
     Table A below summarizes the switch state transitions as the rocker  14  is moved from normally not pivoted, to partially pivoted toward the L-shaped end  20 A, and then to fully pivoted toward the L-shaped end  20 A. 
     
       
         
           
               
             
               
                 TABLE A 
               
             
            
               
                   
               
               
                 Switching States when Rocker Pivoting towards 20A 
               
            
           
           
               
               
               
               
            
               
                   
                 No pivot 
                 Partial pivot to A 
                 Full pivot to A 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                 Contact Switch 21A 
                 closed 
                 open 
                 open 
               
               
                 Key Switch 22A 
                 open 
                 open 
                 closed 
               
               
                 Contact Switch 21B 
                 closed 
                 closed 
                 closed 
               
               
                 Key Switch 22B 
                 open 
                 open 
                 open 
               
               
                   
               
            
           
         
       
     
     Table B below summarizes the switch state transitions as the rocker  14  is moved from normally not pivoted, to partially pivoted toward the L-shaped end  20 B, and then to fully pivoted toward the L-shaped end  20 B. 
     
       
         
           
               
             
               
                 TABLE B 
               
             
            
               
                   
               
               
                 Switching States when Rocker Pivoting towards 20B 
               
            
           
           
               
               
               
               
            
               
                   
                 No pivot 
                 Partial pivot to B 
                 Full pivot to B 
               
               
                   
                   
               
            
           
           
               
               
               
               
            
               
                 Contact Switch 21A 
                 closed 
                 closed 
                 closed 
               
               
                 Key Switch 22A 
                 open 
                 open 
                 open 
               
               
                 Contact Switch 21B 
                 closed 
                 open 
                 open 
               
               
                 Key Switch 22B 
                 open 
                 open 
                 closed 
               
               
                   
               
            
           
         
       
     
     Depressing one end of the rocker  14  opens a normally closed contact ( 21 A or  21 B). If the rocker  14  is pressed further, a normally open contact in the keypad tops ( 27 A or  27 B) is closed while the first (normally open) contact remains open. Since the rocker pivots in the middle and is supported at each end by the spring-like domes of the keypad, when the rocker is released, both switch elements are returned to their original state. Because of this configuration, the switch can function in three ways: (1) as a SPDT normally open momentary switch, (2) as a SPDT normally closed switch, and (3) as a DPDT switch with one set of normally closed and one set of normally open contacts for each pole. In one example application of switch  10  where the switch  10  is connected to control a circuit, when one side of the rocker  14  is depressed, it closes a normally open switch which toggles the circuit to a “ON” state for the function of the corresponding side. Depressing the rocker  14  again (on either side) opens the corresponding normally closed contact and closes the corresponding normally open switch. This last sequence has no effect on the circuit, however when the rocker  14  is released, the normally open switch breaks contact and the normally closed contact re-makes contact. This has the effect of resetting the circuit to the OFF/neutral position awaiting the next input. If either side of the rocker is depressed (and released), that function will turn ON until it is turned OFF and the circuit is reset by the previously described sequence. 
     One example application of the dual mode switch  10  is as a toggle switch to either control a circuit in two states (high or low; hot (H) or cold (C), etc.) plus off, or one of two devices (each on-off) plus all off. When used with a flip-flop circuit, the normally closed contacts can be used to reset the circuit, while the normally open contacts can be used to trigger a control circuit to toggle the device on or off. For example, in a heat/cool application, pressing one side of the rocker  14  would turn on the heat function. Pressing either side of the rocker  14  after the heating (or cooling) is on would then turn it off. Pressing the heating side (or cooling side) once more would turn that function on again, etc. 
     In another example, by depressing one side of the rocker  14 , partially pivoting the rocker  14  onto the keypad top  27 A of normally-open switch  22 A, the normally-closed switch  21 A is opened, while the normally-open switch  22 A remains open. During the period of time when the rocker  14  is partially pivoted (from being not pivoted to being fully pivoted), both switches  21 A and  22 A are open. By further depressing the rocker  14 , fully pivoting the rocker  14  onto the keypad top  27 A of normally-open switch  22 A, the normally-closed switch  21 A remains open and the normally-open switch  22 A is closed. 
     In a reverse action, by depressing the rocker  14  to fully pivot the rocker  14  onto the keypad top  27 B of normally-open switch  22 B, the normally-closed switch  21 B is opened, and the normally-open switch  22 B is closed. During the period of time when the rocker  14  is partially pivoted (from being not pivoted to being fully pivoted), both switches  21 B and  22 B are open. 
     Once pressure on the rocker  14  is released, the decompressing action of the keypad  22 , pushes the rocker  14  back to the un-pivoted state (e.g.,  FIGS. 15-18 ), whereby the switch  10  has a self-centering neutral or a middle/neutral state. When the rocker  14  is partially pivoted towards the L-shaped end  20 A, then the normally-closed switch  21 A is opened. Then, when the rocker  14  is fully pivoted towards the L-shaped end  20 A, the normally-open switch  22 A is closed. Then, when pressure on the rocker  14  is released, the rocker  14  returns to self-centered position whereby switch  22 A is opened again and switch  21 A is closed again. In a reverse action, when the rocker  14  is partially pivoted towards L-shaped end  20 B, then normally-closed switch  21 B is opened. Then when the rocker  14  is fully pivoted towards the L-shaped end  20 B, normally-open switch  22 B is closed. Then, when pressure on the rocker  14  is released, the rocker  14  returns to self-centered position whereby switch  22 B is opened again and switch  21 B is closed again. 
     The contact  20  and/or the keypad  22  are preloaded and their tolerances selected to provide clearances that present the switch  10  from rattling due to vibration. Preferably, the rocker  14  is normally sprung up (supported) to the un-pivoted (centered) position by the keypad  22  and/or the contact  20 , keeping the rocker  14  from pivoting, so that in the un-pivoted position the rocker  14  feels rattle free to user touch. As such, the keypad  22  and/or the contact  20  offers resistance against pivoting of the rocker  14 , and the amount of resistance to pivoting can be selected by selecting the physical characteristics of the contact  20 , and the keypad  22 . The physical characteristics can include height, width, thickness, material, elasticity, etc. The domes  23 A and  23 B are elastic springy semi-rigid and normally uncompressed, and when the rocker  14  is in its centered (un-pivoted) position there is some freeloader effect and domes  23 A,  23 B are very slightly compressed (without closing the normally-open contacts), to keep the rocker  14  stabilized over the keypad  22 . The domes  23 A,  23 B push up against the rocker keeping the rocker  14  from pivoting. 
     In another example, the protrusions  30 A,  30 B of the rocker  14  can be supported, and sprung up, by the L-shaped ends  20 A,  20 B, respectively, of the contact  20 . The rocker protrusions  30 A,  30 B may rest on L-shaped ends  20 A,  20 B, respectively of the springy contact  20 , wherein the L-shaped ends  20 A,  20 B push up against the rocker protrusions  30 A,  30 B, keeping the rocker  14  from pivoting. 
     In another example, the protrusions  32 A,  32 B of the rocker  14  can be supported, and sprung up, by the tops  27 A,  27 B, respectively, of the keypad  22 . This is shown in  FIGS. 15-18 , wherein the protrusions  32 A,  32 B, normally rest on the semi-rigid tops  27 A,  27 B, respectively, without play, and with the tops  27 A,  28 B sprung up against the protrusions  32 A,  32 B, respectively, so that in the un-pivoted (centered) position the rocker  14  feels rattle free to user touch. The domes  23 A,  23 B are elastic/springy/semi-rigid and are normally uncompressed in the sense that the normally open contacts remain open ( FIGS. 19 ,  20 ,  6 ), wherein the domes  23 A,  23 B push the tops  27 A,  27 B against the rocker protrusions  32 A,  32 B, respectively, keeping the rocker  14  from pivoting to either side. 
     Yet in another example, a combination of the above two examples can be utilized, wherein the protrusions  32 A,  32 B of the rocker  14  are supported, and sprung up, by the tops  27 A,  27 B, respectively, of the keypad  22 , and the protrusions  30 A,  30 B of the rocker  14  are supported, and sprung up, by the L-shaped ends  20 A,  20 B, respectively, of the contact  20 . 
     While the present invention is susceptible of embodiments in many different forms, there are shown in the drawings and herein described in detail, preferred embodiments of the invention with the understanding that this description is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiments illustrated. The present invention has been described in considerable detail with reference to certain preferred versions thereof; however, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.