Ground fault circuit interrupter and electronic detection circuit

Claim 2

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a moveable core; at least two pivot arms that rotate in response to the linear movement of the moveable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being responsive to the rotation of one of said pivot arms, said deflectable flexure arms normally biasing said contacts in a closed position; means detecting the occurence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contacts and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; and means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position.

Claim 3

A ground fault circuit interrupter according to claim 1 wherein said pivot arms are coupled together by a catcher which cooperates with the moveable core of said electromagnetic coil means.

Claim 4

A ground fault circuit interrupter according to claim 1 which further includes load terminals electrically coupled to said flexure arms and including two receptacle spring arms disposed at right angle to the insertion of a plug blade.

Claim 5

A ground fault circuit interrupter according to claim 1 which further includes a mounting strap with an aperture therein and a bifurcated ground contact disposed in said aperture and comprised of a mounting tab, a cross structure, and means contacting the ground blade of a plug.

Claim 6

A ground fault circuit interrupter according to claim 4 wherein said means contacting the ground blade of a plug includes a pair of torsional members connected to said cross structure, a blade contact member connected to each of said torsional members and a support tab connected to each of said blade contact members.

Claim 7

A ground fault circuit interrupter according to claim 1 which further includes a housing and a face plate, said housing including at least one snap finger which cooperates with an aperture in said face plate.

Claim 8

A ground fault circuit interrupter according to claim 1 wherein said means for detecting the occurrence of a fault includes a plurality of transformers which are coupled to a printed circuit board having a popaway aperture.

Claim 9

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a moveable core; at least two pairs of contacts, one contact of each pair stationary and the other contact of each pair being disposed on a deflectable member; means applying the operating force of said electromagnetic coil means to directly open said contacts by moving said deflectable members, said deflectable flexure arms normally biasing said contacts in a closed position; means detecting the occurrence of a ground fault in said power distribution system in order to actuate said electromagnetic coil means; and means inhibiting the electromagnetic coil means such that said electromagnetic coil means is not actuated unless there is sufficient energy to cause the contacts to latch in an open position.

Claim 10

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a moveable core; at least two pairs of contacts, one contact of each pair stationary and the other contact of each pair being disposed on a deflectable member; means applying the operating force of said electromagnetic coil means to directly open said contacts by moving said deflectable members, said deflectable flexure arms normally biasing said contacts in a closed position; means detecting the occurrence of a ground fault in said power distribution system in order to actuate said electromagnetic coil means; and means inhibiting the electromagnetic coil means such that said electromagnetic coil means is not actuated unless there is sufficient energy to cause the contacts to latch in an open position.

Claim 11

A ground fault circuit interrupter according to claim 8 which further includes resetting means for preventing said contact from being teased when said contacts are open.

Claim 12

A ground fault circuit interrupt in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the moveable core of said electromagnetic coil means, said pivot arms being coupled together by a catcher that cooperates with the moveable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being responsive to the rotation of one of said pivot arms, said flexure arms including torsion elements that increase the effective length of said flexure arms; means detecting the occurrence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contact and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; and means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position.

Claim 13

A ground fault circuit interrupt in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the moveable core of said electromagnetic coil means, said pivot arms being coupled together by a catcher that cooperates with the moveable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being responsive to the rotation of one of said pivot arms, said flexure arms including torsion elements that increase the effective length of said flexure arms; means detecting the occurrence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contact and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; and means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position.

Claim 14

A ground fault circuit interrupter according to claim 10 wherein said flexure arm has a relatively narrow section and a relatively wide section and said torsion elements are formed by an aperture in said relatively wide section of said flexure arm.

Claim 15

A ground fault circuit interrupter according to claim 11 which further includes a latching mechanism holding said contacts open when said flexure arms are deflected.

Claim 16

A ground fault circuit interrupter according to claim 12 wherein said latching mechanism includes a two member spring responsive to one of said pivoting arms.

Claim 17

A ground fault circuit interrupter according to claim 13 which further includes a reset button operable to release said latching mechanism thereby allowing said contacts to close after the fault has been cleared.

Claim 18

A ground fault circuit interrupter according to claim 14 wherein one of said pivot arms includes an extension which cooperates with said two member spring.

Claim 19

A ground fault circuit interrupter according to claim 15 wherein one of said pivot arms further includes a surface which cooperates with a surface of said reset button.

Claim 20

A ground fault circuit interrupter according to claim 16 wherein said pivot arms include mating gears.

Claim 21

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the movable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being responsive to the rotation of one of said pivot arms; means detecting the occurrence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contacts and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position; and terminal means coupling electrical energy to said contacts, said terminal means including a terminal having a threaded aperture and a cooperating screw with a pressure pad disposed upon said screw.

Claim 22

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the movable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being responsive to the rotation of one of said pivot arms; means detecting the occurrence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contacts and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position; and terminal means coupling electrical energy to said contacts, said terminal means including a terminal having a threaded aperture and a cooperating screw with a pressure pad disposed upon said screw.

Claim 23

A ground fault circuit interrupter according to claim 18 wherein said pressure pad includes a pair of dimples which interface with said screw head.

Claim 24

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the movable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being response to the rotation of one of said pivot arms; means detecting the occurence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contacts and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; and means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position, said inhibiting means including means comparing the cycle associated with the bridge rectifier to a fixed threshold.

Claim 25

A ground fault circuit interrupter in a power distribution system comprising: an electromagnetic coil means having a movable core; at least two pivot arms that rotate in response to the linear movement of the movable core of said electromagnetic coil means; at least two pairs of contacts, one contact of each pair being stationary and the other contact of each pair being disposed on a deflectable flexure arm, each of said deflectable flexure arms being response to the rotation of one of said pivot arms; means detecting the occurence of a fault in said power distribution system in order to actuate said electromagnetic coil means, such that said pivot arms rotate, thereby causing said deflectable flexure arms to separate said contacts and interrupt the flow of current, said detecting means having a bridge rectifier that provides a current to said electromagnetic coil means when a silicon controlled rectifier responds to an imbalance in the power lines; and means inhibiting the operation of the silicon controlled rectifier near the end of a cycle associated with the bridge rectifier, such that the electromagnetic coil means is not actuated if the electric power associated with the cycle is insufficient to cause the contacts to latch in an open position, said inhibiting means including means comparing the cycle associated with the bridge rectifier to a fixed threshold.

Claim 26

A circuit according to claim 20 wherein said inhibiting means includes means comparing the cycle associated with the bridge rectifier to a threshold proportional to the line voltage.

Claim 27

A circuit according to claim 21 wherein the threshold of said comparing means is provided by an ac-coupled differentiating network.

Claim 28

A circuit according to claim 22 where said ac-coupled differentiating network includes means generating a waveform having twice the frequency of the cycle associated with the bridge rectifier.

Claim 29

A circuit according to claim 23 where the waveform, having twice the frequency of the cycle associated with the bridge rectifier, controls a transistor which shorts the gate of the silicon controlled rectifer.

Claim 30

A circuit according to claim 24 wherein said ac-coupled differentiating network includes a transistor, a zener diode connected in series with a capacitor and a resistor connected between the base of said transistor and the junction of said zener diode and said capacitor.