Cooper Industries, Inc.

Mcgraw-edison Company

Cooper Power Systems, Inc.

John Lapp

Stephen P Hassler

Stephen P Johnson

Gary L Goedde

Gary A Gauger

Fred S Sadler

Alan Paul Yerges

Marco J Mason

John R Willy

James V White

Edward F Veverka

David W Anderson

Stephen P Haasler

Hui-Min Chai

Larry B Hackney

The present invention comprises a mixture of hydrocarbons having a well-defined chemical composition that is suitable for use as a dielectric coolant in electrical equipment in general, and specifically in transformers. The dielectric coolants of the present invention are particularly suited for use in sealed, non-vented transformers, and have improved performance characteristics, including decreased degradation of the paper insulating layers, as well as a greater degree of safety and environmental acceptability. The present dielectric coolants comprise relatively pure blends of compounds selected from the group consisting of aromatic hydrocarbons, polyalphaolefins, polyol esters, and natural vegetable oils, along with additives to improve pour point, increase stability and reduce oxidation rate.

Dielectric fluid having defined chemical composition for use in electrical apparatus

Electrical apparatus with dielectric fluid blend of polyalphaolefins and polyol esters or triglycerides

A delay mechanism for retarding relative movement between two members has particular application in a hinge assembly for a dropout fuseholder. In one embodiment, a pin member rotatably connecting two adjacent members is disposed through a sleeve which has a cavity filled with viscous material, such as silicon putty. Protrusions extending from the shaft of the pin engage the putty and retard the relative rotational movement of the two members. In another embodiment, a friction member, such as a washer or annular seal, is disposed between the adjacent rotatable members. The friction member has facing surfaces contacting the opposing surfaces of the rotatable members such that the frictional forces between the friction member and the rotatable members retard rotation. In still another embodiment, the hinge assembly of a dropout fuseholder includes a latch member which rotates away from the fuseholder once dropout is initiated. As this occurs, the latch member draws a plug member through a putty-filled chamber in the fuseholder. The plug member includes extending projections which engage the viscous putty to retard rotation of the latch member. Additionally, dashpot devices may be employed between the various members of the hinge assembly to retard relative movement.

Delay mechanism for retarding relative movement between two members

A current responsive latching apparatus may be employed in a dropout fuseholder or other electrical component for retaining the component in a current-carrying position and disconnecting and isolating the electrical component upon the occurrence of an overcurrent of a predetermined magnitude. The apparatus includes a current path through the component, including a current-carrying stud or conductor, a portion of which extends outside the component for releasably engaging a support member. A latching apparatus, which may include an actuating member of memory allow or a bimetallic material, engages the conductor to retain the support member in a supporting position beneath the electrical component. The apparatus may further include a heater element in the current path to ensure that the actuation member is heated to the temperature necessary to cause it to change shape and release the conductor upon the presence of an overcurrent.

Current responsive latching apparatus for disconnecting and isolating an

Dielectric fluid for use in power distribution equipment

A current-limiting dropout fuseholder includes multiple current paths through the fuse body. A primary current path includes a high current fusible element. A secondary current path in parallel with the primary path includes a triggering conductor that extends outside the fuse body and is connected to a moveable support. The second current path further includes a first spark gap for severing the triggering conductor upon the occurrence of a fault and the shifting of the fault current from the primary current path to the second current path. A second spark gap formed between the primary and the second current paths ensures that the fault current flows across the first spark gap for a time sufficient to sever the triggering conductor, thereby ensuring that dropout will occur.

Current limiting fuse and dropout fuseholder

An electrical apparatus, such as a transformer, includes an expandable internal chamber that is nonventing and completely and permanently sealed from the ambient environment. The chamber houses a core and coil assembly or other current-carrying conductor and is completely filled with dielectric fluid having a pressure less than one atmosphere. The enclosure walls are flexible and are permitted to bow inwardly and outwardly as the volume of the dielectric fluid changes due to thermal expansion and contraction. A method of processing the dielectric fluid and filling and sealing the transformer at sub-atmospheric pressure is also disclosed.

Hermetically sealed, non-venting electrical apparatus with dielectric

A terminal bushing having integral overvoltage and fault current protection includes an insulator having an upper and a lower chamber. Nonlinear resistors are disposed in the upper chamber between a top terminal and an intermediate terminal which are mounted on the insulator. The top terminal, the nonlinear resistors and the intermediate terminal form a first current path through the bushing. The bushing also includes a pair of mounting arms which support a current limiting dropout fuseholder. The fuseholder is disposed in series between the top terminal and a bushing stud which is retained in the lower chamber of the bushing body. A second current path through the bushing is thus formed by the top terminal, the fuseholder and the bushing stud.

Terminal bushing having integral overvoltage and overcurrent protection

An apparatus for retarding rotation of a pin member, comprising: a sleeve having a body and a chamber within the body, the sleeve body comprising first and second coaxial body segments, the first body segment including a reduced-diameter portion and the second body segment including a counterbore sized to receive the reduced-diameter portion, the reduced diameter portion being axially longer than the counterbore, such that a circumferential recess is formed when the reduced diameter portion is slidingly received in the counterbore; a pair of aligned apertures in the body; a shaft disposed through the apertures and adapted for rotation within the chamber; viscous material surrounding the shaft and substantially filling the shaft and substantially filling the voids in the chamber; and extensions on the shaft for engaging the viscous material and retarding rotation of the shaft in the chamber.

The fuseholder includes a current limiting fuse mounted within a fuse body and a lower contact and hinge assembly. The fuse body has contact assemblies mounted on each end thereof. The lower contact assembly on the fuse body is mounted on a hinge which is rotatably supported on an interchangeable cutout mounting. The current limiting fuse includes a fuse element spirally wound around a spider which extends the length of the fuse body. The fuse element includes a high current fusible element and a low current fuse element. The fusible element includes a plurality of spaced reduced areas and is supported on the spider by support surfaces which are located between adjacent reduced areas of the fusible element. An auxiliary wire also extends the length of the fuse body about the spider. The hinge includes a hinge member rotatably mounted on the interchangeable cutout mounting, a connective member supporting the contact assemblies and fuse body with current limiting fuse, and a latch for latching the hinge member to the connective member in a contracted position. The latch is connected to a trigger wire attached to the lower end of the auxiliary wire to maintain the hinge and connective members in their contracted position. Upon the melting of the trigger wire due to a current overload, the trigger wire releases the latch thereby allowing the connective member to move to an extended position with respect to the hinge member such that the current limiting fuse drops out of the interchangeable cutout mounting.

Current limiting fuse having compact structure

An improved load break disconnecting device is disclosed, comprising a conductive portion having a non-gassing fuse, a fuse cartridge having first and second ends and enclosing said fuse, a conducting hinge assembly and conducting stationary contact means, and a non-conducting arc extinguishing sleeve with latch means for latching the sleeve in a non-covering position until the switch is closed and biasing means for snapping the sleeve into an arc-extinguishing, covering position when the switch is opened.

Growing community of inventors

Franklin, WI, United States of America

John Lapp