Patent Publication Number: US-7211758-B2

Title: Circuit interrupter that produces snap-action connection and disconnection between electrical contacts

Description:
TECHNICAL FIELD 
   The invention relates to a system and method for minimizing arcing and contact welding between electrical contacts in an on/off switch. The invention relates more particularly to a circuit interrupter that produces a snap-action connection and disconnection between the electrical contacts. 
   BACKGROUND 
   Electrical circuits of various kinds are susceptible to a number of unfavorable conditions. For example, in an on/off switch, arcing or sparking may occur between electrical contacts when such paired contacts bounce or partially separate upon toggling the switch to the off position. This condition is referred to as a teasable condition in an electrical system. Furthermore, the contacts of such an electrical system may weld together causing the circuit to remain closed even after the switch has been in the off position for a number of cycles. 
   Such an on/off switch is commonly used in the triggers of hand operated devices such as main line powered construction tools and latterly powered gardening tools. In these types of devices, the contact pressure directly relates to the trigger travel (i.e., the distance over which the trigger is moved or depressed). The user directly controls the trigger travel by pulling and relaxing his finger over the trigger. However, the contact pressure between electrical contacts in the switch may approach zero when a user only partially toggles the trigger to the on position. In extreme cases, if a tool operator holds the trigger in the on position while current is running through the contacts at near zero contact pressure, the contacts may weld together. In such circumstances, even after the operator has released the trigger, the circuit will remain closed. The powered tool cannot be turned off easily, causing a safety hazard. This condition poses potential hazards to nearby materials, equipment and to humans, including the operator. 
   There is a need for an invention that can quickly provide full contact pressure between the electrical contacts and that can cause the electrical contacts to disconnect quickly. Thus, there is a need for an invention in which the contact pressure does not depend upon the trigger travel so as to avoid teasing after the switch is turned on. 
   SUMMARY OF THE INVENTION 
   The present invention overcomes and/or minimizes the problems of the prior art switches described above. The present invention provides for a system and method for minimizing the chances of teasing between electrical contacts in an electrical circuit. In particular, a preferred embodiment constructed in accordance with the principles of the present invention provides a non-teasable switch that is independent of trigger travel. 
   An exemplary embodiment of a switch for preventing teasing in an electrical circuit includes a first contact movable toward a second contact from a switch-deactuated position to a switch-actuated position and movable away from the second contact from the switch-actuated position back to the switch-deactuated position. The first contact releasably contacts the second contact in the switch-actuated position and separates from the second contact in the switch-deactuated position. A transfer assembly moves the first contact in and out of contact with the second contact and between the switch-actuated and switch-deactuated positions. 
   In one exemplary embodiment, the transfer assembly includes a transfer carriage operatively engaged with the first contact and movable toward and away from the second contact between the switch-actuated and switch-deactuated positions. The transfer carriage incorporates a flip-flop mechanism that moves the first contact into a first position to contact with the second contact, or into a second position to separate the first contact from the second contact. The flip-flop mechanism overcomes a force or energy barrier (i.e., a transfer barrier) to switch between the switch-actuated and switch-deactuated positions. The transfer barrier must be overcome in order to move between the two positions. 
   The transfer assembly further includes an actuator engaged with the transfer carriage and movable toward and away from the second contact in the same linear motion as the carriage. The actuator causes the transfer carriage and thus the first contact to move between the switch-deactuated and switch-actuated positions. Conceptually, the actuator provides the transfer carriage with sufficient energy to overcome the transfer barrier between the switch-deactuated and switch-actuated positions. 
   An exemplary method for preventing teasing in an electrical circuit includes providing a switch as described herein. The method includes pushing the actuator from a switch-deactuated position in the direction of the second contact. The actuator thereby pushes the transfer carriage and the first contact toward the second contact. The actuator pushes the transfer carriage against biasing members, thereby storing a first transfer energy in the flip-flop mechanism. Applying further pressure on the actuator causes the flip-flop mechanism to generate enough energy to overcome the transfer barrier. Upon overcoming the barrier, the flip-flop changes states, and at least some of the stored energy is released to push the first contact into the switch-actuated position, thereby closing the circuit. The first and second contacts make contact after the flip-flop mechanism moves the transfer carriage past the transfer point toward the second contact. 
   The actuator is released from the switch-actuated position using an external spring to move the actuator away from the second contact. Moving the actuator moves the transfer carriage and stores a second transfer energy in the flip-flop mechanism. Contact between the first and second contact is broken and the circuit is opened when the flip-flop mechanism changes states and moves the transfer carriage and the first contact out of contact with the second contact. The external spring generates sufficient force to allow the mechanism to overcome the energy barrier when the actuator is moved past the transfer point using the second stored transfer energy 
   The switch and transfer assembly as herein described prevents teasing that may occur between contacts in a circuit. The improved switch prevents arcing and sparking. Contact welding may also be avoided. Preferably, the switch is incorporated in triggers for hand operated power tools used, for example, in construction and gardening applications. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Like reference numbers generally indicate corresponding elements in the figures. 
       FIG. 1A  illustrates an elevated side view of one embodiment of a switch 
       FIG. 1B  illustrates a perspective view of the switch of  FIG. 1A . 
       FIG. 1C  illustrates a perspective view of the other side of the switch of  FIG. 1B . 
       FIG. 2  illustrates an elevated perspective view of one exemplary embodiment of an actuator body and a carriage body. 
       FIG. 3  illustrates an elevated perspective view of the actuator body of  FIG. 2  including an exemplary embodiment of an attached trigger insert. 
       FIG. 4  illustrates an elevated perspective view of one embodiment of a carriage body in accordance with the principles of the present invention. 
       FIG. 5  illustrates a partial perspective view of the carriage body shown in  FIG. 4 . 
       FIG. 6  is an elevated view of an exemplary embodiment for a switch cover interacting with the first and second contacts shown in  FIGS. 4 and 5 . 
       FIG. 7  is a partial perspective view of the switch shown in  FIG. 1A  with the switch housing removed. 
       FIG. 8A  illustrates one embodiment of a switch in the release state. 
       FIG. 8B  illustrates an elevated perspective view of an actuator, carriage body, and contacts arranged in a stage  1  state. 
       FIG. 9A  illustrates an elevated perspective view of select components of  FIG. 8B  arranged in a stage  2  state. 
       FIG. 9B  illustrates an elevated perspective view of the opposite side of the components shown in  FIG. 9A . 
       FIG. 10A  illustrates an elevated perspective view of the select components of  FIG. 8B  arranged in a stage  3  state. 
       FIG. 10B  illustrates an elevated perspective view of the opposite side of the components shown in  FIG. 10A . 
       FIG. 11A  illustrates an elevated perspective view of the components of  FIG. 8B  arranged in a stage  4  state. 
       FIG. 11B  illustrates an elevated perspective view of the opposite side of the components shown in  FIG. 11A . 
       FIG. 12A  illustrates an elevated perspective view of the components of  FIG. 8B  arranged in a stage  5  state. 
       FIG. 12B  illustrates an elevated perspective view of the opposite side of the components shown in  FIG. 12A . 
       FIG. 13A  illustrates an elevated perspective view of the components of  FIG. 8B  arranged in a stage  6  state. 
       FIG. 13B  illustrates an elevated perspective view of the opposite side of the components shown in  FIG. 13A . 
       FIG. 14A  illustrates a partial perspective view of one embodiment of a switch including an exemplary embodiment of a lock device in an unlocked state, the switch being in a switch-deactuated position. 
       FIG. 14B  illustrates a partial perspective view of the switch as shown in  FIG. 14A  having the lock device in a “lock on” state and the switch in a switch-actuated position. 
       FIG. 14C  illustrates a partial perspective view of the switch as shown in  FIG. 14A  having the lock device in a “lock release” state and the switch not yet transited to a switch-deactuated position. 
       FIG. 14D  illustrates a partial perspective view of another exemplary embodiment for a lock device for a switch having the lock device in a “lock off” state and the switch in a switch-deactuated position. 
       FIG. 14E  illustrates a partial perspective view of the switch as shown in  FIG. 14D  having the lock device in a lock-off state and the switch in a switch-activated position. 
       FIG. 15  illustrates a schematic of an exemplary embodiment of a wiring pattern for a switch in accordance with the principles of the present disclosure. 
       FIG. 16A  illustrates a schematic of an exemplary embodiment of a single-pole, single-throw, non-teasable switch in accordance with the principles of the present disclosure. 
       FIG. 16B  illustrates a schematic of multiple exemplary embodiments of single-pole, single-throw, non-teasable switches arranged in parallel in accordance with the principles of the present disclosure. 
       FIG. 17A  illustrates a schematic of an exemplary embodiment of a double-pole, single-throw, non-teasable switch in accordance with the principles of the present disclosure. 
       FIG. 17B  illustrates a schematic of multiple exemplary embodiments of double-pole, single-throw, non-teasable switches arranged in parallel in accordance with the principles of the present disclosure. 
       FIG. 18A  illustrates a schematic of an exemplary embodiment of a single-pole, single-throw, non-teasable switch including a number of bus bars to drive a number of loads in accordance with the principles of the present disclosure. 
       FIG. 18B  illustrates a schematic of an exemplary embodiment of a multiple-pole, single-throw, non-teasable switches including a number of bus bars to drive a number of loads in accordance with the principles of the present disclosure. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In broad terms, embodiments of a switch are configured to minimize teasing between contacts in an electrical circuit. In a switch-actuated position, the switch provides sufficient contact pressure between contacts to close the circuit. Conversely, in a switch-deactuated position, the switch removes all contact pressure between the contacts to open the circuit. However, although the switch is described below in terms of an electrical wired circuit, this is exemplary only, and certain embodiments of the present invention may be suitable for use with other known circuit arrangements. 
     FIGS. 1A–1C  illustrate exemplary embodiments of a switch  10  including a trigger  30 , which is movable between a switch-actuated position and a switch-deactuated position. The trigger  30  includes a trigger insert  34  (best seen in  FIG. 3 ) that connects with an actuator  20  (best seen in  FIG. 2 ). According to one embodiment, when activated (e.g., depressed), the trigger  30  pushes the actuator  20  toward the transfer carriage  40  (best shown in  FIGS. 4 and 5 ) to move the switch  10  into the switch-actuated position. In this switch-actuated position, a first contact (as seen in  FIG. 4 , reference no.  12 ) is moved into a depressed contact position, in which the first contact physically touches a second contact (as seen in  FIG. 5 , reference no.  18 ). According to one embodiment, one or both of the first and second contacts include multiple contacts. 
   Conversely, the trigger  30  releases the actuator  20  and transfer carriage  40  when toggled into the switch-deactuated position. Moving the actuator  20  causes the first contact  12  to move into a released contact position, in which the first contact is separated from the second contact  18 . The trigger  30  may be activated by any mechanical pressure, including pressure applied by an operator. However, the invention is not limited to mechanical pressure and the trigger  30  may also be activated by automated control. 
   Still referring to  FIGS. 1A–1C , one embodiment of a switch  10  includes a housing  70  and cover  90  for protecting switch components. The housing  70  and cover  90  are arranged and configured to be coupled together such that the switch components are positioned within the volume created by the housing  70  and cover  90 . One embodiment of the cover  90  is provided with side flanges  95  for connecting the cover  90  to the housing  70 . 
   As best shown in  FIG. 6 , one embodiment of the cover  90  includes a terminal block  92  and terminal frame  94  mounted thereon. The terminal block  92  and terminal frame  94  provide physical support for the second contacts  18  and include connecting terminals  2 M,  2 C and line input L 2 , which are discussed in further detail herein. In one embodiment, sleeve  98  is provided at one end of the cover  90  to protect the actuator  20 . The circuit will close when the first contacts  12  contact the second contacts  18 , such that an electric current flows from terminal block  92  to the terminal frame  94  through the bridge plate  14 . While the current flows through the bridge plate  14 , current creepage may occur. Cover ribs  96  are provided on a surface of the cover  90  to decrease current creepage by increasing the distance through which the creepage would need to pass. 
   Referring back to  FIGS. 1B and 1C , the housing  70  includes line inputs. As shown, a first line input L 1  and second line input L 2  reside on a side of the housing  70  as input holes. The line inputs hole L 1 , L 2  provide wire connection means for the switch to connect to a power source (not shown). Terminals  1 M,  2 C,  2 M and  2 C are disposed on the opposite side of the housing  70 . First and second load side terminals  1 M,  2 M are provided on opposite sides of the cover  90 . Additionally, first and second capacitor side terminals  1 C,  2 C are provided between the load side terminals  1 M,  2 M. 
   Referring now to  FIG. 15 , the relationship between the line inputs L 1 , L 2  and the terminals  1 M,  2 M,  1 C and  2 C can be schematically illustrated in an exemplary wiring pattern. Preferably, the line input wire  1 N and  2 L may be respectively inserted into the line inputs hole L 1  and L 2  (shown in  FIG. 1C ) to connect a power source P to the switch. First and second load terminals  1 M and  2 M provide a connection to a motor (e.g., a power tool motor) for operating the motor. First and second capacitor side terminals  1 C and  2 C provide a connection to a capacitor X 2  (e.g., an EMI filter). Preferably, terminals  1 M and  1 C and input wire  1 N are internally connected within the switch  10 . 
   Still referring to  FIG. 15 , the switch  10  is toggled on and off by connecting and separating terminals  2 M and  2 C with line input wire  2 L. The round nodes SC on either end of the circuit denote the second contacts  18 . These nodes SC come into or out of contact with first contact nodes FC via a contact bridge B (e.g., bridge plate  14  as shown in  FIG. 4 ). The contact between first contacts FC and second contacts SC connects terminal  2 M with input wire  2 L, thereby closing the circuit. The bridge B delivers the first contacts FC to the second contacts SC and connects terminal  2 M with input wire  2 L, thereby closing the circuit. The bridge B delivers the first contacts FC to the second contacts SC via movement of the transfer carriage  40  and the actuator  20  (as shown in  FIG. 2 ). 
   It is emphasized that the support structures as illustrated, including the trigger  30 , housing  70 , and cover  90 , represent one exemplary embodiment only and that other arrangements may be equally suitable. Additionally, the arrangement shown of line inputs L 1 , L 2  and terminals  1 M,  2 M,  1 C, and  2 C in  FIG. 15  represents only one exemplary embodiment and that other arrangements may be equally suitable. 
   Referring back to  FIGS. 1A–1C , one embodiment of the switch  10  includes a lock device  50  mounted on the housing  70 . The lock device  50  provides a lock-on and a lock-off function to the trigger  30 . The lock device  50  is further discussed herein with reference to  FIGS. 14A–14E . 
     FIGS. 2–4  show an exemplary embodiment of an actuator  20  and transfer carriage  40  of a transfer assembly  200 . The actuator  20  includes a shaft  22 . The shaft  22  is connected to a carriage container  24  at a first end, and includes interlocks  26  at a second, opposite end. The carriage container  24  is receivable of the transfer carriage  40 . Preferably, the transfer carriage  40  is slidable within the carriage container  24 , such that actuator  20  and transfer carriage  40  move relative to one another. In one embodiment the transfer carriage  40  resembles a trolley-like structure that is movable linearly within the carriage container  24 . More preferably, the carriage container  24  is substantially a boxed receptacle for housing the transfer carriage  40  therein. 
   In  FIG. 3 , one embodiment of the actuator  20  may be connected to a trigger insert  34  for supporting the trigger  30 . Preferably, the actuator  20  is externally activated by a switch operator via the trigger  30 . In one preferred configuration, the trigger insert  34  may be securely connected to the actuator  20  by applying a fastener  35  (e.g., an e-ring), to lock the trigger insert  34  to the actuator  20 . In particular, the fastener  35  is used to engage the interlocks  26  of the actuator  20 . The trigger insert  34  provides ease of connection between the actuator  20  and the trigger  30 , so that the actuator  20  may be comfortably activated and released by the switch operator. 
   One side of the carriage container  24  includes first and second actuator cutouts  28 ,  29 . Preferably, the actuator cutouts  28 ,  29  are disposed as pairs on opposite sides of actuator  20 , such that they extend in the longitudinal direction of shaft  22 . The actuator cutouts  28 ,  29  will be discussed in further detail herein. 
   Referring now to  FIG. 4 , the transfer carriage  40  includes a first set of carriage cutouts  49   a  and a second set of carriage cutouts  49   b . Preferably, the first set of carriage cutouts  49   a  are disposed on opposite ends of the transfer carriage  40  and extend transversely to the longitudinal direction of the shaft  22 . Preferably the second set of carriage cutouts  49   b  (best shown in  FIG. 2 ) are disposed on opposite sides of the transfer carriage  40  and extend in same direction as the first actuator cutouts  28 ,  29  and shaft  22 . The first carriage cutouts  49   a  provide a space for first and second carriage plates  42   a ,  42   b  to slide therethrough. 
   The shoulder portions of the transfer carriage  40  surrounding the first carriage cutouts  49   a  retain biasing surfaces  43   a ,  43   b . Preferably, the biasing surfaces  43   a ,  43   b  are biased outward by a first bias member  44   a  pushing against the biasing surfaces  43   a ,  43   b . For example, in  FIG. 4  the first bias member  44   a  is illustrated as compressed against the second carriage plate  42   b , which has been slid towards the first carriage plate  42   a . Alternately, the first carriage plate  42   a  could slide towards the second carriage plate  42   b , thereby compressing the first bias  44   a  against the first carriage plate  42   a  in a similar manner. In one embodiment, the first bias  44   a  is a spring. 
   Referring now to  FIGS. 5–7 , the bridge plate  14  is slidingly engaged with the transfer carriage  40  along the second carriage cutouts  49   b . The bridge plate  14  includes the first contacts  12  disposed on either end of the bridge plate  14 . The first contacts  12  face towards the second contacts  18 , which are located on one end of the transfer carriage  40 . Preferably, the bridge plate includes grooves (best shown in  FIG. 6 ). According to one embodiment, a second carriage biasing member  44   b  biases the bridge plate  14  toward the second contacts  18 . In one exemplary configuration, the bridge plate  14  slides along the second carriage cutouts  49   b  and along the first actuator cutouts  28  to deliver the first contacts  12  into and out of contact with the second contacts  18 . 
   According to one embodiment, the second contacts  18  are fixed on the terminal frame  94  and terminal block  92  as shown in  FIGS. 5 and 6 . When the transfer carriage  40  is slid along the actuator  20 , the bridge plate  14  is moved towards and away from the second contacts  18  so as to connect and separate the first and second contacts  12 ,  18 . In one embodiment, the first contacts  12  are arranged as a first and second contact pad that come into and out of contact with a corresponding pair of contact pads for the second contacts  18 . The bridge plate  14  connects the pads in order to close the circuit. 
   In another embodiment, the bridge plate  14  also include magnets  16  disposed on the opposite side of the bridge plate  14  from which the contact pads of the first contacts  12  are located. In this kind of configuration, the bridge plate is pulled towards the second contact  18  to provide sufficient contact pressure on the contacts  12 ,  18 . Preferably, a potential difference exists between the terminal block  92  and the terminal frame  94 . Preferably, the magnets  16  and the terminal block and frame  92 ,  94  may have a difference in magnet polarity. Alternatively, either the magnets  16  or terminal block and frame  92 ,  94  can have a magnetic field and the other can be composed of iron. As will be discussed in detail below, the transfer carriage  40  snaps on and off in a short period of time to close and break the circuit. 
   Referring back to  FIG. 4 , one embodiment of the transfer carriage  40  includes at least one cam member  48 . Another embodiment of the transfer carriage  40  includes cam member  48  oppositely disposed on either side of the transfer carriage  40 , opposite the second carriage cutouts  49   b . The cam members  48  move in the same longitudinal direction as the actuator  20  when the trigger  30  is activated to move the actuator  20  and the transfer carriage  40 . 
   Referring now to  FIG. 7 , a transfer barrier prevents the transfer carriage  40  from moving towards the second contacts  18  unless sufficient force is applied to the actuator  20  and transfer carriage  40  to overcome the transfer barrier. Preferably, the transfer barrier includes an assembly of cam balls  60  biased toward the transfer carriage  40  by ball biasing members  62 . In one embodiment, the cam balls  60  and ball biasing members  62  are supported by ball stops  64 . Preferably, ball stops  64  are insertable into the housing  70  at holes  75 . In another embodiment, the ball stops  64  include a waved contour so that they are self-locked in the housing holes  75  via an interference fit. In one exemplary embodiment, the cam balls  60  are steel balls that lock the cam members  48  so as to prevent movement of the transfer carriage  40  even when the actuator  20  is initially moved. 
   Referring back to  FIGS. 2 and 4 , the transfer assembly  200 , which includes the actuator  20 , the transfer carriage  40 , and a flip-flop mechanism, operates in cooperation with the transfer barrier. The flip-flop mechanism preferably includes the first and second carriage plates  42   a ,  42   b  operating in cooperation with the first biasing member  44   a . The flip-flop mechanism further includes the bridge plate  14  and second biasing member  44   b . The cam members  48  of the transfer carriage  40  cooperate with the transfer barrier to prevent movement of the transfer carriage  40 . The transfer barrier includes the cam balls  60 , ball biasing members  62 , and ball stoppers  64 . 
     FIG. 8A  illustrates the switch  10  having the transfer assembly arranged in a switch-deactuated position.  FIG. 8B  illustrates the transfer assembly of the switch  10  including the actuator  20 , transfer carriage  40 , a flip-flop mechanism, and contacts  12 ,  18  arranged in the switch-deactuated position. To transition out of the switch-deactuated position, a switch operator activates the actuator  20  via the trigger  30 , which causes the transfer carriage  40  to move relative to the actuator  20 . The actuator  20  is moved to initiate delivery of the transfer carriage  40  and first contact  12  toward the second contact  18 . 
   When the actuator  20  is moved toward the second contacts  18 , a transfer barrier prevents movement of the carriage  40  by providing an energy barrier. Preventing movement of the carriage  40  while moving the actuator  20  causes transfer energy to build up in the flip-flop mechanism. The transfer carriage  40  is locked from movement until a sufficient amount of energy is input into the system. When a sufficient amount of energy is provided via the trigger  30 , the transfer carriage  40  overcomes the transfer barrier. When the transfer barrier is overcome, the flip-flop mechanism changes states, thereby moving the carriage  40  towards the second contacts  18 . The switch  10  now is in the switch-actuated position and a transfer barrier prevents movement back to the switch-deactuated position. 
   Referring now to  FIGS. 8A–14B , various stages of select components within the switch  10  are illustrated describing toggling of the switch  10  between switch-actuated and switch-deactuated positions.  FIGS. 8A and 8B  illustrate components of the switch  10  arranged in a stage  1  “release state.”  FIGS. 9A–9B  illustrate the select components shown in  FIG. 8B  arranged in a stage  2  “first energy build up” state in which the actuator  20  is moved further towards the second contacts  18 . The actuator  20  presses against the transfer carriage  40  to move the cam members  48  up to the cam balls  60  of the transfer barrier, such that the transfer carriage  40  is at a transfer point. The first biasing member  44   a  is compressed, thereby creating and storing transfer energy in the first carriage biasing member  44   a  at the transfer point. 
     FIGS. 10A–10B  illustrate the select components of  FIG. 8B  arranged in a stage  3  “fly to on” state. If further pressure is applied to the actuator  20 , the transfer carriage  40  will overcome the transfer barrier and be free to move past the transfer point. In particular, the energy built up from the compression of the first biasing member  44   a  enables the cam members  48  of the transfer carriage  40  to overcome the resistance of the cam balls  60 . The cam members  48  are allowed to move as a result of the space created by the second actuator cutouts  29 . Thus, there is no force to resist movement of the transfer carriage  40 , towards the second contact  18 . At this point, the cam members  48  quickly slide (i.e., or fly) over the cam balls  60 . Thus, the cam balls  60  retract away from the transfer carriage  40  by compression of the ball biasing members  62  toward the ball stops  64 . 
     FIGS. 11A–11B  illustrate the select components of  FIG. 8B  arranged in a stage  4  “switch on” state. Once the transfer carriage  40  overcomes the transfer barrier and moves past the cam balls  60 , the bridge plate  14  is delivered toward the second contacts  18 . Thus, the first contacts  12  come into contact with the second contacts  18 , thereby closing the circuit. This is analogous to the schematic wiring pattern illustrated in  FIG. 16  discussed above. Sufficient contact pressure is maintained between the first and second contacts  12 ,  18  through the second biasing member  44   b . The energy built up from compression of the first biasing member  44   a  at stage  2  is released in pushing the bridge plate  14  towards the second contacts  18 . 
     FIGS. 12A–12B  illustrate the select components of  FIG. 8B  arranged in a stage  5  “second energy pile up” state. At this point, even if the actuator  20  is released, the transfer barrier retains the transfer carriage  40  in the “switch on” state such that contact between the first and second contacts  12 ,  18  is maintained. The actuator  20  must now be moved in a direction away from the second contacts  18  in order to toggle the switch to the switch-deactuated position. The first biasing member  44   a  is then compressed in a manner similar to stage  2 , but from the opposite side. Second carriage plate  42   b  is slid through first carriage cutout  49   a , such that the second biasing surface  43   b  compresses the first biasing member  44   a  against the first biasing surface  43   a  of the first carriage plate  42   a . A second transfer energy is stored at a second transfer point where the cam members  48  are pushed against the cam balls  60  from the opposite side. This energy storage configuration is analogous to the first energy storage configuration of stage  2  illustrated in  FIGS. 9A–9B . 
     FIGS. 13A–13B  illustrate the select components of  FIG. 8B  arranged in a stage  6  “fly to off” state. After the actuator  20  is further released, the transfer carriage  40  is pulled away from the second contacts  18  with sufficient force to overcome the cam balls  60 . Thus, the cam members  48  slide quickly over the cam balls  60 , thereby releasing the second transfer energy stored in stage  5 . The release causes the bridge plate  14  to quickly separate from the second contacts  18 . This configuration is analogous to the “fly to on” state of stage  3  illustrated in  FIGS. 10A–10B , except that the transfer carriage  40  and bridge plate  14  are moving in the opposite direction. After this stage, the select components of the switch  10  return to the stage  1  “release” state. Thus, one switch-actuated/switch-deactuated position cycle is completed. 
   It is emphasized that this description represents one exemplary embodiment only and the invention is not limited to the specific arrangement as described herein. For instance, it will appreciated that the biasing members  44   a ,  44   b ,  62  described may be any biasing member that is equally suitable for the desired application, are not limited to the coil springs as shown. Thus, other arrangements for the switch components may vary as necessary to suit any desired application. 
   Referring now to  FIGS. 14A–14E , a locking device  50  maintains the transfer carriage  40  in the closed circuit position (i.e., or “switch on” state) or maintains the transfer carriage  40  in the “release” position.  FIGS. 15A–15E  illustrate partial perspective views of the lock device  50  of the switch  10 . Relevant components are shown for purposes of illustration. It is emphasized that the lock device  50  shown in  FIGS. 14A–14E  is exemplary only as other arrangements may be equally suitable. 
     FIGS. 14A–14C  illustrate the lock device  50  respectively in the “lock off, switch off” state, the “lock on, switch on” state, and the “lock off, switch on” state. According to one embodiment, the lock device  50  includes a lock button  51 . The lock button  51  includes a fastener  51   a  that connects to a reciprocating member  51   b . The reciprocating member  51   b  is movable into and out of the housing  70 . According to another embodiment, a lock biasing member  54  is disposed within the lock button  51 . Preferably, the lock biasing member  54  is disposed annularly about the fastener member  51   a  and reciprocating member  51   b . The lock button  51  is connected to the housing  70  through an annular collar  59 . The lock button  51  and collar  59  provide a biasing space  56  therebetween, such that the lock button  51  may move into and out of the annular collar  56 . A reciprocating space  55  is provided within the housing  70 , such that the reciprocating member  51   b  may reciprocate into and out of the housing  70 . 
   The lock button  51  connects with a lock device lever  52  to engage a catch member  58 . As shown in  FIG. 14A , the lever  52  is shown released from the catch member  58  in a “lock off, switch off” position. In  FIG. 14B , the lever  52  is shown engaged with the catch member  58  in a “lock on, switch on” position.  FIG. 14C  illustrates the lever  52  released from the catch member  58  in a “lock off, switch on” position. 
     FIGS. 14D–14E  illustrate an alternative embodiment for the lock device  50 . As shown in  FIGS. 14D–14E , a lock device shoulder  38  may be employed such that the switch  10  is locked in a switch-deactuated position and released in a switch-actuated position.  FIG. 14D  shows the lock device  50  in a “lock on, switch-deactuated” stage.  FIG. 14E  shows the lock device  50  in a “lock off, switch-actuated” stage. 
   It will be appreciated that while the lock device  50  may be preferable for switch operation, it may not be necessary in all embodiments. 
   FIGS.  16 (A-B)– 19 (A-B) illustrate multiple schematic arrangements for using a non-teasable switch  100 . In brief,  FIG. 16A  illustrates one embodiment of a switch  100  as a single-pole, single-throw, non-teasable switch. This configuration is analogous to the wiring pattern having a motor shown in  FIG. 15 .  FIG. 16B  illustrates a schematic for multiple single-pole, single-throw, non-teasable switches  100  arranged in parallel. 
     FIG. 17A  illustrates an embodiment of a non-teasable switch  101  arranged in a double-pole, single-throw, non-teasable switch  101  configuration.  FIG. 17B  illustrates multiple double-pole, single-throw, non-teasable switches  101  arranged in parallel. 
     FIG. 18A  illustrates a single-pole, single-throw, non-teasable switch  103  and further including a number of bus bars  102  to drive a number of loads.  FIG. 18B  illustrates multiple-pole, single-throw, non-teasable switches  103  including a number of bus bars to drive a number of loads. 
   The switch as herein described prevents teasing that may occur between contacts in a circuit, thereby preventing arcing and sparking. Welding of contacts may also be avoided when using this switch. Preferably, the switch is incorporated in a trigger for a hand operated power tool. It is emphasized that this application is exemplary only. The switch is not limited only to use with electrical circuits as described. It may also be adaptable for use with other known on/off circuits for preventing teasing. The non-teasable switch is also not limited only to the uses described herein. Other arrangements that produce similar functionality may be equally suitable. 
   Furthermore, it is particularly noted that various embodiments of the switch may be adapted for use with various currents and voltages, and either AC or DC power. Moreover, as previously indicated, the present invention is not limited exclusively to electrical circuit interruption. Moreover, the switch is not limited only to the particular arrangement of electrical circuits shown and described herein. Embodiments of the present invention may be suitable for use with circuits operating at a variety of AC and DC voltages, and/or a variety of AC and DC currents. 
   Although the switch is described herein in terms of a device that is integrated into an electrical circuit, this is exemplary only. Certain embodiments of the present invention may be suitable for partial or total integration into larger circuits, appliances, or other devices. However, other embodiments of the present invention may be suitable for use as modules used with other circuits or devices. 
   The above specification, examples and data provide a complete description of the manufacture and use of the composition of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.