Transformer bushing

A bushing assembly for use with a tank-type electrical transformer adapted to be inserted through an opening in the outer casing of the electrical transformer, said bushing assembly being comprised of a bushing stud and means for securing said stud to the transformer, said bushing stud comprising:

• a first connector portion made of a conductive material and adapted for connection to an electrical lead within the transformer,
• a securing portion integral with and made of the same conductive material as said first connector portion, but of a larger diameter, said securing portion adapted to be mounted on the outside of the tank adjacent the outer casing of the electrical transformer and having threads adjacent said securing portion extending through the opening in the casing into the inside of the tank,
• a second connector portion integral with and made of the same conductive material as said first connector portion and said securing portion, but of a smaller diameter than said securing portion, said second connector portion adapted for connection to an electrical lead outside the transformer,
• said securing portion having a relatively thin layer of insulating material thereon, and
• said means for securing said stud to the transformer comprising a threaded securing member having insulating properties and being adapted for locating said securing portion on the outside of the tank adjacent the outer casing of the electrical transformer, by engaging the threads adjacent said securing portion which extend into the inside of the tank.

A bushing assembly for use with an electrical transformer having a casing, said bushing assembly being adapted to protrude through an opening in the casing of the electrical transformer in order to provide electrical connection between electrical conductors on opposite sides of the casing, said bushing assembly comprising conductor means and clamping means for securing said conductor means to the transformer, said conductor means including first and second connector portions electrically integral with one another and composed of an electrically conductive material, said first and second connector portions being adapted for electrical connection to said electrical conductors on opposite sides of the casing of the electrical transformer, at least one of said first and second connector portions extending longitudinally through the opening in the casing of the electrical transformer, said conductor means further including a composite securing flange fixedly extending laterally from a generally intermediate location along said bushing assembly generally between said first and second connector portions, said composite securing flange including an electrically conductive inner member and a relatively thin outer coating of electrically insulating material following the contour of said inner member, said relatively thin outer coating of electrically insulating material being of a substantially uniform thickness and extending over a part of each of said connector portions generally adjacent said composite securing flange, said composite securing flange being generally plate-like in configuration with its longitudinal thickness being substantially less than the longitudinal length of said first and second conductors and with its lateral dimensions being substantially larger than the lateral dimensions of said first and second conductors, said composite securing flange further being adapted to be mounted generally adjacent the casing of the electrical transformer with said thin outer coating of electrically insulating material interposed between said inner member of said composite securing flange and said casing, said clamping means including a clamp member engageable with said conductor means and having an opening for receiving at least one of said first and second connector portions extending therethrough and attachment means for securing said clamp member to one side of the casing, said engagement between said clamp member and said conductor means biasing said composite securing flange toward said one side of the casing of the electrical transformer, said composite securing flange being generally hex-shaped, said clamp member being a generally laterally-extending plate-like member of a generally triangular shape and having a wall portion extending generally longitudinally from each of the three sides thereof, said clamp member further being adapted to receive said generally hex-shaped composite securing flange between said wall portions with three of the sides of said composite securing flange aligned in a generally mating registry with the three sides of said clamp member and with the remaining three sides of said composite securing flange generally aligned with but laterally shaped from the apexes of said clamp member, said first three sides of said composite securing flange laterally interfering with the three sides of said clamp member when in said mating registry with one another to prevent said composite securing flange and said connector portions from rotating laterally relative to said clamp member, one of said attachment means for securing said clamp member to the casing being located generally between each of said remaining three sides of said composite securing flange and its associated apex of said clamp member, said attachment means comprising a number of threaded fastener means mounted on said one side of the transformer casing, said composite securing flange having an aperture extending through each of said spaces between said three apexes of said clamp member and said remaining three sides of said composite securing flange, said apertures being aligned for receiving one of said fastener means extending through each of said apertures.

A bushing assembly for use with an electrical transformer having a casing said bushing assembly being adapted to protrude through an opening in the casing of the electrical transformer in order to provide electrical connection between electrical conductors on opposite sides of the casing, said bushing assembly comprising conductor means and clamping means for securing said conductor means to the transformer, said conductor means including first and second connector portions electrically integral with one another and composed of an electrically conductive material, said first and second connector portions being adapted for electrical connection to said electrical conductors on opposite sides of the casing of the electrical transformer, at least one of said first and second connector portions extending longitudinally through the opening in the casing of the electrical transformer, said conductor means further including a composite securing flange fixedly extending laterally from a generally intermediate location along said bushing assembly generally between said first and second connector portions, said composite securing flange including an electrically conductive inner member and a relatively thin outer coating of electrically insulating material following the contour of said inner member, said composite securing flange being generally plate-like in configuration with its longitudinal thickness being substantially less than the longitudinal length of said first and second conductors and with its lateral dimensions being substantially larger than the lateral dimensions of said first and second conductors, said composite securing flange further being adapted to be mounted generally adjacent the casing of the electrical transformer with said thin outer coating of electrically insulating material interposed between said inner member of said composite securing flange and said casing, said clamping means including a clamp member engageable with said conductor means and having an opening for receiving at least one of said first and second connector portions extending therethrough and attachment means for securing said clamp member to the casing, said engagement between said clamp member and said conductor means biasing said composite securing flange toward one side of the casing of the electrical transformer.