Abstract: According to this invention, therein is provided a puffer-type compressed gas circuit interrupter comprising stationary and movable contacts and a stationary cylinder, a movable piston, connected to the movable contacts and which slides in the stationary cylinder to compress the sulfur hexafluoride insulating gas therebetween to provide a puffing action to extinguish the arc drawn between the separating stationary and movable contacts. The puffer apparatus is disposed within an insulating tube which has a plurality of openings therein disposed about the stationary contact. The tube, with the puffer apparatus disposed therein, is disposed within an outer metallic housing in which an insulating barrier is further disposed between the insulating tube and the housing. The insulating barrier, which lines the inside of the outer housing, is disposed adjacent to the apertures in the insulating tube so as to prevent a dynamic insulation breakdown to ground.

Abstract: This invention provides a new circuit interrupter construction utilizing a means of mounting the interrupter units on the roof of the control housing that supports the drive mechanism and other control apparatus.

Abstract: An improved oil-pumping piston-assembly is provided for an oil-type circuit-interrupter to improve the interrupting performance during low-current conditions, having an improved hydraulic-dashpot action occurring during charging and discharging oil, incorporating, additionally, a "floating" piston design, and reducing the mechanical impulse forces exerted on the cylinder when high-current interruptions are made with an improved check-valve construction.The improved oil-pumping piston-assembly of the present invention is particularly adapted for the inclusion therewith of an auxiliary shunting separable-contact structure, which will, when desired, increase the current-carrying capability of the circuit-interrupter. Its inclusion, or exclusion, is optional, depending upon the current rating desired by the utility customer.

Abstract: A tank-type oil circuit-breaker has a pair of arc-extinguishing grid-structures disposed interiorly within the oil tank, each of said arc-extinguishing grid-structures having a pair of outwardly-directed horizontally-laterally-spaced venting ports, with the angular direction, or divergence between the two horizontally-spaced venting ports of somewhat critical angular magnitude.The construction is such that the two spaced venting ports on each arc-extinguishing grid structure collectively produce a resultant inwardly-directed jet force, which substantially counterbalances the outwardly-directed magnetic and mechanical forces resulting from the U-shaped line-current flow passing through the circuit-interrupter.The angular separation, or angular divergence provided between the two horizontally-laterally-spaced venting ports of each arc-extinguishing grid-structure falls within the range of angular magnitude of 80.degree. to 160.degree.. A desirable divergence range is between 100.degree. and 140.degree.

Abstract: An oil-type circuit-breaker has an improved grid structure for effecting quick extinction of the arc, which is established and lengthened within the grid structure by the separation of the rod-shaped movable contact downwardly away from the stationary-contact structure. The grid structure is constructed by providing a plurality of suitably-configured plate elements, constituting vent passages and oil pockets, within an outer cylindrical shell member. The stationary contact assembly is so arranged as to have a lengthened finger, which serves as an arcing horn, disposed adjacent the side lateral vent openings. The vent openings are formed by passages provided in the individual suitably-configured plate elements; and a splitter plate is interposed between the lateral vent passages and close to the path of movement of the movable contact rod.