ELECTRICAL BUS BAR CONSTRUCTION AND METHOD OF MAKING SAME

• US 3,634,810 A
• Filed: 02/03/1970
• Issued: 01/11/1972
• Est. Priority Date: 02/03/1970
• Status: Expired due to Term

• Current Assignee: Donald L. Pemberton
• Original Assignee: Donald L. Pemberton
• Inventors: Pemberton, Donald L.
• Primary Examiner(s): Moore, Richard E.
• Assistant Examiner(s): Hafer, Robert A.
• Application Number:
  US05/008,303
• Time in Patent Office: 707 Days
• Field of Search: 339/20,21,22B,278 174/71B,82B,88B,99B,133B,129 72/377
• US Class Current: 439/114
• CPC Class Codes: H02G 5/06 Totally-enclosed installations, e.g. in metal casings
• CPC Class Codes: H02G 5/08 Connection boxes therefor

Abstract

An improved bus bar and method of making same is disclosed wherein an elongated electrical conductor is formed having a roughly V-shaped cross-sectional configuration comprised of a bight and a pair of diverging legs having inside surfaces which are easily accessible and the inside surfaces are initially coated with an electrically conductive metallic material having a lower surface resistivity of oxidation than the electrical conductor and the coated conductor is then worked so that the diverging legs are arranged in substantially parallel relation to define a receptacle for an associated male unit. This disclosure also presents an improved bus bar assembly and method of making same.

Claims

1. A method of making an electrical bus bar comprising the steps of, forming an elongated electrical conductor having a roughly Vshaped cross-sectional configuration comprised of a bight and a pair of diverging legs having inside surfaces which are easily accessible, coating said inside surfaces with an electrically conductive metallic material to define a coated conductor, and working the coated conductor so that said diverging legs are arranged in substantially parallel relation to define a plug-in receptacle for a male unit, said V-shaped cross-sectional configuration requiring minimum working of said coated conductor to thereby assure there is no damage to the coating applied on said inside surfaces.

2. A method as set forth in claim 1 in which said forming step comprises forming said electrical conductor by an extrusion process.

3. A method as set forth in claim 1 in which said coating step comprises coating said inside surfaces with an electrically conductive material having a lower surface resistivity of oxidation than said electrical conductor.

4. A method as set forth in claim 1 in which said coating step comprises electrolytically depositing a coating on said inside surfaces having a thickness generally of the order of ten-thousandths of an inch.

5. A method as set forth in claim 1 in which said forming step comprises extruding a metallic material containing aluminum, said working step comprises mechanically bending said diverging legs toward each other, and said coating step comprises coating said inside surfaces with said electrically conductive material having a lower surface resistivity of oxidation than said electrical conductor.

6. A method of making a plug-in electrical bus bar assembly comprising the steps of, providing a plurality of elongated electrical bus bars each having a substantially U-shaped cross-sectional configuration defined by a bight and a pair of substantially parallel legs extending therefrom to define an open channel along the full length thereof, arranging said bus bars with their open channels facing in the same direction, placing a layer of an electrical insulating material between each immediately adjacent pair of said bus bars, wrapping a high strength electrically insulating tapelike material around said bus bars to produce an electrically insulated beamlike assembly, and providing access openings in said tapelike material enabling male members of a plug-in unit to be inserted within said open channels.

7. A method as set forth in claim 6 and comprising the further step of installing said beamlike assembly in a protective housing having a plurality of cutouts therein so that said access openings are aligned with said cutouts to enable said male members to be easily inserted within said open channels.

8. A method as set forth in claim 7 in which said placing step comprises placing said electrical insulating material in the form of a thin sheet between each immediately adjacent pair of said bus bars, said wrapping step comprises wrapping said tapelike material so that the total thickness of the tapelike material is kept at a minimum, and said installing step comprises installing said beamlike assembly in said protective housing made of a highly thermally conductive material so that heat buildup in said assembly is easily conducted to the surrounding environment.

9. A method as set forth in claim 6 in which said providing step comprises individually forming each of said plurality of elongated electrical bus bars so that initially each has a roughly V-shaped cross-sectional configuration compRised of said bight and a pair of diverging legs having inside surfaces which are easily accessible, coating said inside surfaces of said bight and diverging legs of each bus bar with a metallic material to define a coated conductor, and working the coated conductor so that the diverging legs thereof are arranged in substantially parallel relation to define said substantially U-shaped cross-sectional configuration.

10. A method as set forth in claim 9 in which said forming step comprises forming each of said electrical conductors by an extrusion process.

11. A method as set forth in claim 9 in which said forming step comprises roll forming each of said electrical conductors.

12. A method as set forth in claim 9 in which said coating step comprises electrolytically depositing a coating on said inside surfaces of each of said electrical bus bars having a thickness generally of the order of ten-thousandths of an inch.

13. A method as set forth in claim 9 in which said coating step comprises electrolytically depositing a coating of an electrically conductive material on said inside surfaces of each of said electrical bus bars wherein said material has a lower surface resistivity of oxidation than the base material comprising the bus bar.

14. A method as set forth in claim 9 in which said forming step comprises extruding a metallic material containing aluminum to define each of said bus bars, said working step comprises mechanically bending the diverging legs of each bus bar toward each other, and said coating step comprises coating the inside surfaces of each of said bus bars with an electrically conductive material having a lower surface resistivity of oxidation than the metallic material of the bus bars.

15. An electrical bus bar assembly comprising, a plurality of elongated electrical bus bars each having a substantially U-shaped cross-sectional configuration defined by a bight and a pair of substantially parallel legs extending therefrom to define an open channel along the full length thereof, a layer of electrical insulating material between each immediately adjacent pair of bus bars, and a tapelike material around said bus bars with said bus bars arranged with their open channels facing in the same direction, said tapelike material providing an electrically insulated beamlike assembly having high structural strength and providing optimum short circuit bracing, said tapelike material having access openings provided therein enabling the male members of a plug-in unit to be inserted within said open channels.

16. An assembly as set forth in claim 15 and further comprising a protective housing for said beamlike assembly, said housing having a plurality of cutouts therein arranged in aligned relation with said access openings.

17. An assembly as set forth in claim 16 in which each layer of electrical insulating material between each immediately adjacent pair of bus bars is in the form of a thin insulating sheet, said tapelike material is in the form of a high-strength tape which is wrapped in position so that the thickness of insulation is kept at a minimum yet is sufficient to provide optimum electrical insulation, and said protective housing is made of a metallic material which is a good heat conductor so that heat buildup in said bus bar assembly is conducted to the environment in which said assembly is placed with optimum efficiency.

18. An assembly as set forth in claim 17 in which each of said bus bars is made of a metallic material containing aluminum and the surfaces defining the channel in each bus bar are coated with an electrically conductive material which has a lower surface resistivity of oxidation than the metallic material of the bus bars.