Energy efficient floating head puffer interrupter

A circuit interrupter, comprising:

• a. a first cylinder which is open at both ends and which is adapted to be filled with an arc extinguishing gas;
• b. a pair of electrical contacts including a first electrical contact, which is disposed within and carried by said first cylinder, and including a second electrical contact which is disposed within said first cylinder and which is free to move into and out of engagement with said first electrical contact so as to form an electrical switch;
• c. a first piston, disposed reciprocatingly within said first cylinder, said first piston being movable between a first position and a second position;
• d. a second piston, disposed reciprocatingly within said first cylinder to move between a third position and a fourth position, said third position and said second position being intermediate said first and said fourth positions, said first piston and second piston and said first cylinder defining a pressurizing chamber which is in fluid communication with the gap defined by said switch contacts when said contacts are disengaged;
• e. biasing means, carried by said first cylinder for biasing said second piston to its fourth position;
• f. pressurizing means for driving said first piston between its first and second positions, pressure being developed in said pressurizing chamber by driving said first piston toward said second piston;
• g. pressurizing valve means, operated in response to the movement of said second electrical contact, for discharging fluid from said pressurizing chamber into said switch gap when said first piston is intermediate said first position and said second position;
• h. first time sequencing means, operatively connected to said first piston and said second electrical contact, for closing said switch by moving said second electrical contact into engagement with said first electrical contact, and for opening said switch after said first piston is intermediate its first and second positions,
• whereby pressure is developed within said pressurizing chamber by stroking said first piston and is not discharged by said pressurizing valve means into the gap between said switch contacts until after an arc is formed between said contacts as said contacts are separated;
• and
• i. second time sequencing means, carried by said second electrical contact, for overcoming said biasing means and driving said second piston from its fourth position to its third position when said switch is closed by said first time sequencing means, said second piston being free to move from its third position under the influence of said biasing means after said pressurizing valve means begins to open,
• whereby the pressure within said pressurizing chamber is controllably released in response to the movement of said second electrical contact and the power required to reposition said first piston and pressurize said fluid is consumed more uniformly than that power consumed if said second piston were fixed in position.

A gas-blast type circuit interrupter, comprising:

• a. a casing for containing an arc extinguishing gas;
• b. a pair of separable electrical contact elements co-axially disposed within said casing, at least one of said contact elements being moveable between a closed position and an open position and having a hollow interior open at two ends, an electrical arc being established within said hollow interior after contact separation when current is passing through said contact elements prior to separation;
• c. mechanical means, including a puffer chamber disposed within said casing, for pressurizing said arc extinguishing gas before separation of said contact elements, and for moving said one contact element between its closed and open positions;
• d. valve means for establishing fluid communication from said puffer chamber to the interior of said one contact element when said contact elements are separated beyond a pre-determined distance from each other during separating movement of said one contact element;
• and
• e. pressure control means, disposed within said puffer chamber, for moderating the pressure variations within said puffer chamber as said contact elements are separated.

An interrupter, comprising:

• a. a tank-like housing which is adapted to contain an arc extinguishing fluid and defining a generally cylindrical interior tank wall;
• b. a pair of tubular, co-axially disposed, separable electrical contact elements carried by said tank, one of said contact elements being movable between a separated position and an abutted position where said contact elements are in an end to end abutting relationship, each of said tubular contact elements having a venturi at its abutting end and an arcing probe centrally disposed therein at a spaced distance from the respective venturi such that an electrical arc is formed between said arcing probes upon separation when current is passed across said contact elements prior to separation and arc extinguishing fluid is forced into each venturi in the direction of said arcing probes;
• c. a reciprocating puffer piston co-axially disposed around the other contact element and in sealing relationship with the exterior of said other contact element and said interior tank wall so as to be movable between a first position and a second position;
• d. prime mover means for moving said one contact element between its separated and abutting positions and for moving said puffer piston reciprocatingly towards and away from the gap defined by said contact elements when they are separated from each other;
• e. a floating piston, co-axially disposed around said one contact element and in a sealing relationship with said interior tank wall so as to be movable between a primary and a secondary position, said primary position lying intermediate the first position of said puffer piston and the separated position of said one contact element, said puffer piston and said floating piston together with said interior tank wall and the exterior of said contact elements defining an annular pressurization chamber when said one contact element is in its abutted position;
• f. means, carried by said tank, for biasing said floating piston towards its secondary position;
• g. stop means, carried by said one contact element, for driving said floating piston from its secondary position to its primary position, whereby the position of said floating piston is determined by the operation of said prime mover means;
• and
• h. delay means, operatively connecting said prime mover means and said one contact element, for delaying the separation of said contact elements until said puffer piston has been moved by said prime mover means to a position intermediate its first and second positions, whereby the fluid within said pressurization chamber is pressurized before said contact elements are separated and the maximum pressure within said pressuriztion chamber is less than the maximum pressure which would be achieved if said floating piston were fixed in position.