A method of creating a switch, comprising disposing a switching element movably within an interior cavity of the switch to define switch-making and switch-breaking positions along a switching axis of the switching element, disposing a biasing element about the switching element to impart a biasing force to the switching element to place the switching element in one of the switch-making and switch-breaking positions until an external force imparted to the switching element exceeds the biasing force to cause the switching element to change to the other position, disposing a biasing force-adjusting element in cooperative engagement with the biasing element such that a magnitude of the biasing force is adjustable, and coupling a conductive contact to the switching element to define a switch-making state when the switching element is in the switch-making position and a switch-breaking state when the switching element is in the switch-breaking position.

A method of creating a switch, comprising disposing a switching element movably within an interior cavity of the switch to define switch-making and switch-breaking positions along a switching axis of the switching element, disposing a biasing element about the switching element to impart a biasing force to the switching element to place the switching element in one of the switch-making and switch-breaking positions until an external force imparted to the switching element exceeds the biasing force to cause the switching element to change to the other position, disposing a biasing force-adjusting element in cooperative engagement with the biasing element such that a magnitude of the biasing force is adjustable, and coupling a conductive contact to the switching element to define a switch-making state when the switching element is in the switch-making position and a switch-breaking state when the switching element is in the switch-breaking position.

A motor-driven surgical instrument that may comprise (i) a moveable drive member that is driven in a first direction when the electric motor operates in a first direction and that is driven in a second direction when the electric motor operates in a second direction. Movement of the drive member causes movement of the moveable component of the end effector, and (ii) a motor control circuit connected to the motor for controlling the motor. The motor control circuit may comprise a switching circuit that, upon actuation, reverses the direction of the motor from the first direction to the second direction. The switching circuit may be actuatable separately through each of: (i) actuation of a moveable actuator of the switching circuit through movement of the drive member at least in the first direction; and (ii) manual actuation by a user of the surgical instrument.

A motor-driven surgical instrument that may comprise (i) a moveable drive member that is driven in a first direction when the electric motor operates in a first direction and that is driven in a second direction when the electric motor operates in a second direction. Movement of the drive member causes movement of the moveable component of the end effector, and (ii) a motor control circuit connected to the motor for controlling the motor. The motor control circuit may comprise a switching circuit that, upon actuation, reverses the direction of the motor from the first direction to the second direction. The switching circuit may be actuatable separately through each of: (i) actuation of a moveable actuator of the switching circuit through movement of the drive member at least in the first direction; and (ii) manual actuation by a user of the surgical instrument.

A dual mode thermal actuator (hereafter the actuator) comprises a first cup defining a first chamber filled with thermally-responsive wax and a second cup defining a second chamber filled with thermally-responsive wax. A piston is disposed between the first and second cups. A first guide is received by the first cup. The first guide surrounds the piston and extends axially away from the first cup. A second guide is received by the second cup. The second guide surrounds the piston and extends axially away from the second cup. Expansion of the wax in the first chamber or expansion of the wax in the second chamber causes the actuator to go from a retracted position to an extended position. Expansion of the wax in the first chamber and expansion of the wax in the second chamber also causes the actuator to go from the retracted position to the extended position.

A caster-wheel assembly (100; 200) for a vehicle, for example a wheelchair or powered wheelchair. The caster-wheel assembly comprises a switch (13) coupled to a housing (3); a castering wheel bracket (9) configured to receive a wheel (10), wherein the bracket is rotatably mounted about a caster pivot axis (28) with respect to the housing; biasing means (15) configured to provide a biasing force such that the wheel bracket is biased away from the housing; and a switch-actuating member (13) coupled to the wheel bracket such that movement of the wheel bracket towards the housing and against the biasing force causes the switch-actuating member to actuate the switch.

A caster-wheel assembly (100; 200) for a vehicle, for example a wheelchair or powered wheelchair. The caster-wheel assembly comprises a switch (13) coupled to a housing (3); a castering wheel bracket (9) configured to receive a wheel (10), wherein the bracket is rotatably mounted about a caster pivot axis (28) with respect to the housing; biasing means (15) configured to provide a biasing force such that the wheel bracket is biased away from the housing; and a switch-actuating member (13) coupled to the wheel bracket such that movement of the wheel bracket towards the housing and against the biasing force causes the switch-actuating member to actuate the switch.

A switch is provided with: a base; a fixed contact member that has a fixed contact; a movable contact member that has a movable contact, moves in a first direction to bring the movable contact into contact with the fixed contact, and moves in a second direction opposite to the first direction to separate the movable contact from the fixed contact; an elastic body that energizes the movable contact member in the second direction; and a cover that covers the fixed contact member and the movable contact member. An operation body is configured to move the movable contact member sequentially to a first position to which the movable contact member is moved from an initial position in the first direction to bring the contacts into contact with each other, a second position to which the movable contact member is moved from the first position in the second direction while the contacts are kept in contact, and a third position at which the movable contact member is moved again in the first direction from the second position, the third position located between the first position and the second position.

A circuit arrangement for switching an electrical load comprising an electrical switching element with a control input and an output; a control unit connected to the control input to drive the electrical switching element, in a first switching state, to generate a first output signal forming a switch-on signal for the load and, in a second switching state, to generate a second output signal, smaller than the first output signal, forming a switch-off signal for the electrical load; a safety output connected electrically to the electrical switching element output and to which the electrical load is connected; a decoupling apparatus arranged between the electrical switching element output and the safety output; a first output signal detecting apparatus connected to the electrical switching element output; and a second output signal detecting apparatus arranged in a circuit path between the decoupling apparatus and the safety output.

A circuit arrangement for switching an electrical load comprising an electrical switching element with a control input and an output; a control unit connected to the control input to drive the electrical switching element, in a first switching state, to generate a first output signal forming a switch-on signal for the load and, in a second switching state, to generate a second output signal, smaller than the first output signal, forming a switch-off signal for the electrical load; a safety output connected electrically to the electrical switching element output and to which the electrical load is connected; a decoupling apparatus arranged between the electrical switching element output and the safety output; a first output signal detecting apparatus connected to the electrical switching element output; and a second output signal detecting apparatus arranged in a circuit path between the decoupling apparatus and the safety output.