Reducer bushing for weatherproof outlet boxes

• US 6,992,252 B1
• Filed: 03/29/2005
• Issued: 01/31/2006
• Est. Priority Date: 03/29/2005
• Status: Active Grant

• Current Assignee: Sigma Electric Manufacturing Corporation
• Original Assignee: Sigma Electric Manufacturing Corporation
• Inventors: Alilughatta, Ashok Sathyanarayana, Scheer, David L., Rao, C. Gireesh
• Primary Examiner(s): PATEL, DHIRUBHAI R
• Application Number:
  US10/907,314
• Time in Patent Office: 308 Days
• Field of Search: 174/65.R, 174/64, 174/65.SS, 174/14.BH, 174/11.BH, 174/135, 174/50, 174/58, 174/60, 220/3.2, 403/195, 248/906, 439/535
• US Class Current: 174/651
• CPC Class Codes: H02G 3/0691 Fixing tubing to casing by auxiliary means co-operating with indentations of the tubing, e.g. with tubing-convolutions
• CPC Class Codes: H02G 3/083 Inlets

Abstract

A removable reducer bushing is carried in a threaded port of an outlet box for coupling with a small threaded conduit and electively removable for coupling with a large threaded conduit thereby permitting a single box to handle multiple conduit sizes without separately procured parts. The bushing includes a deformable thread interruption resisting bushing rotation during removal of the small threaded conduit and frontal slots for manual removal of the bushing with a screwdriver against the resistance of the thread interruption.

Claims

1. In an electrical system having an outlet box member with at least one threaded port for coupling with a threaded end of a first conduit of a first size, a reducer bushing for facilitating coupling with a threaded end of a second conduit of a smaller second size, said reducer bushing comprising:

an annular body having an annular front surface and an annular rear surface, an exterior threaded surface for coupling with the threaded port of the box member and an interior threaded surface for coupling with the threaded end of the second conduit, said exterior threaded surface having an enlarged deformable portion swaged in the coupling with the port providing increased mechanical resistance to uncoupling of said annular body; and

a pair of diametrically opposed slots formed in said front surface for receiving a bladed tool for developing a torque overcoming said mechanical resistance and effecting uncoupling of said annular body from the threaded port.

2. The electrical system as recited in claim 1 wherein said exterior threaded surface comprises a helical pipe thread of multiple turns having diverging side surfaces and said enlarged deformable portion extends outwardly from said side surfaces.

3. The electrical system as recited in claim 2 wherein said deformable portion has generally cylindrical outer surfaces.

4. The electrical system as recited in claim 3 wherein said deformable portion includes an outwardly opening aperture defining with said cylindrical outer surfaces a thin wall that is swaged in coupling with the threaded port.

5. The electrical system as recited in claim 4 wherein said helical pipe threads includes about five turns.

6. The electrical system as recited in claim 5 wherein said deformable portion is formed at an intermediate turns of said helical pipe threads.

7. An outlet box for coupling with threaded ends of first and second conduits of differing size, said outlet box member comprising:

a housing body having a plurality of ports communicating with an outwardly opening cavity, said ports including an inwardly threaded section for threaded coupling the threaded end of one of the conduits;

bushing members each including an annular body having an outer threaded section coupled with a threaded port, said outer threaded section an enlarged deformable section deformed during said coupling and effective for increasing mechanical engagement with said threaded section of said port, said annular body having an inner threaded section coupled with said threaded section of the other of said conduits, said annular body having an outer section extending outwardly of said housing body and including a pair of diametrically opposed slots for operative engagement with the blade of a removal tool, the arrangement being such that said mechanical engagement is sufficient to resist rotation of said bushing member during decoupling of said other of said conduits and the removal tool can develop sufficient decoupling force to overcome said mechanical resistance and effect removal of said bushing member from said port.

8. The outlet box as recited in claim 7 wherein said enlarged section a radially extending cylindrical member having deformable outer walls.

9. The outlet box as recited in claim 8 wherein cylindrical member includes an outwardly opening circular aperture thereby providing said deformable outer walls.

10. The outlet box as recited in claim 8 wherein said cylindrical member radially outwardly terminates at the diameter of said outer threaded section.