Open Back Junction Box and Method for Pre-fab Wiring

• US 20100084184A1
• Filed: 12/11/2009
• Published: 04/08/2010
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: ERICO International Corporation (nVent Electric Plc)
• Original Assignee: Bruce G. Phillips
• Inventors: Phillips, Bruce G.
• Granted Patent: US 8,455,772 B2
• Time in Patent Office: Days
• US Class Current: 174/535
• CPC Class Codes: H02G 3/00 Installations of electric cables or lines or protective tubing therefor in or on buildings, equivalent structures or vehicles installations of bus-bars H02G5/00; overhead installations H02G7/00; installations in or on the ground H02G9/00
• CPC Class Codes: H02G 3/126 with supporting means for mounting on a single wall stud

Abstract

A bracket and open back junction box assembly allows simplified wiring at a construction site. An open back junction box including a detachable and reattachable rear cover plate is pre-assembled with a plaster ring, electrical device, and leads, at a prefab facility. A Metal Clad (MC) cable may be attached to the open back junction box and wires carried in the MC Cable may be connected to the leads. A mounting bracket is generally sandwiched between the open back junction box and the plaster ring for mounting to framing members at the construction site. Following assembly at the prefab facility, the prefab open back junction box is shipped to the construction site where the bracket and open back junction box assembly is mounted to framing members. Connections to wires carried by MC Cables are then facilitated by removing the rear cover plate to access the open back junction box interior.

Claims

1. A prefab bracket and open back junction box assembly comprising:

an open back junction box having four sides, opposite ones of the sides being parallel;

a plaster ring attached to the open back junction box;

a mounting bracket sandwiched between the plaster ring and the open back junction box;

an electrical device attached to the plaster ring;

electrical leads attached to the electrical device;

wire nuts residing over free ends of each electrical lead; and

a detachable rear cover plate attached to the back of the open back junction box over the open back.

2. The prefab bracket and open back junction box assembly of claim 1, further including an electrical conduit attached to the open back junction box and carrying wires extending into the open back junction box, the wires attached to the electrical leads.

3. The prefab bracket and open back junction box assembly of claim 1, further including a protective cover over a face of the electrical device

4. The prefab bracket and open back junction box assembly of claim 1, further including a fire putty pad residing to the back of the open back junction box.

5. The prefab bracket and open back junction box assembly of claim 4, wherein the fire putty pad is attached to an inside surface of the detachable rear cover plate.

6. The prefab bracket and open back junction box assembly of claim 1, further including prefab wires carried by the prefab electrical conduit to the leads.

7. The prefab bracket and open back junction box assembly of claim 6, wherein the electric conduit is selected from Metal Clad (MC) Cable and Electrical Metal Tubing (EMT).

8. The prefab bracket and open back junction box assembly of claim 1, further including labels attached to the leads to identify the leads.

9. An open back junction box comprising:

four sides, opposite ones of the sides being parallel;

an open front for attachment of a prefab bracket and plaster ring;

an open rear, the edge of the open rear lipless; and

an integral threaded ground screw receptacle residing inside the open back junction box.

10. The open back junction box of claim 9, wherein:

the open back junction box has a depth D; and

the open back junction box is formed from a single metal stamping having a width D for most of the length of the stamping.

11. The open back junction box of claim 9, wherein:

the open back junction box has a depth D and four sides, opposite ones of the sides being parallel;

the open front includes at least two first corner tabs for attachment of an attachable and removable plaster ring, the first corner tabs having a width W1

the open rear includes at least two second corner tabs for attachment of an attachable and removable rear cover plate, the second corner tabs having a width W2; and

the open back junction box is formed from a single metal stamping having a maximum width D plus W1 plus W2 for the length of the stamping.

12. A prefab bracket and open back junction box assembly comprising:

an open back junction box;

a plaster ring attached to the open back junction box;

a mounting bracket sandwiched between the plaster ring and the open back junction box;

an electrical device attached to the plaster ring;

a protective cover over a face of the electrical device;

electrical leads attached to the electrical device;

labels attached to the leads to identify the leads.

wire nuts residing over free ends of each electrical lead;

an integral threaded ground screw receptacle for attachment of a ground screw;

a detachable rear cover plate attached to the back of the open back junction box over the open back; and

a fire putty pad is attached to an inside surface of the detachable rear cover plate.