Anti-twist service fitting for use with underfloor wiring duct

Claim 2

A service fitting for an underfloor wiring duct, the fitting comprising a base having a circular opening for the passage of wires, a tubular adapter received in the circular opening in the base, and a clamping plate fixedly secured to the adapter and having a planular portion overlying the base for holding the base against a floor surface, characterized in that the opening in the base has a plurality of circumferentially, closely spaced slots about its periphery, the space between said slots being substantially equal and the clamping plate has an interlocking portion extending outwardly from the plane of the planular portion overlying the base and received in a selected one of the slots, the base being fixedly held in a pre-selected angular position with respect to the clamping plate and adapter.

Claim 3

A service fitting as claimed in claim 1 wherein the base has upstanding flange portions and a cover of the fitting is secured to the flange portions.

Claim 4

A service fitting as claimed in claim 1 wherein the opening in the base is generally circular and the clamping plate has an additional projecting portion received in a slot diametrically opposite said selected slot.

Claim 5

A service fitting as claimed in claim 1 wherein a collar is provided to serve as a conduit for wires passing from an opening in a wiring duct through said adapter and opening in the base, and the adapter is fixedly secured to the collar.

Claim 6

A service fitting as claimed in claim 4 wherein the collar portion is circular and internally threaded, the adapter has a circular externally threaded lower portion threaded into the collar and a pair of axially extending diametrically opposed grooves in its outer surface, the intersection of the grooves with the threaded interior of the collar defining pair of gaps, a plurality of outwardly extending circumferentially spaced flanges on an upper portion of the adapter overlying the base, two of the flanges having respective openings aligned respectively with the gaps, and threaded screws passing through respective openings in the clamping plate and the openings in the flanges and threaded into the respective gaps, whereby the base, adapter and collar are held in non-rotatable relationship.

Claim 7

An underfloor wiring duct having an upstanding collar portion defining an access opening, and means for securing a base portion of a service fitting thereto, the base portion having a circular opening therethrough for the passage of wires, said securing means including a service fitting adapter secured to the collar and extending upwardly therefrom, a clamping plate fitted over the end of the adapter remote from the duct and having a planular portion overlying the base portion and clamping the base portion to a floor surface, means securing the clamping plate to the adapter, a plurality of circumferentially closely spaced slots about the periphery of the opening in the base portion said slots being substantially equal and the clamping plate having a tang angularly disposed with resPect to the plane of the planular portion and received in a selected one of said slots to prevent relative rotation between the clamping plate and the base portion.

Claim 8

An underfloor wiring duct having an upstanding collar portion defining an access opening, and means for securing a base portion of a service fitting thereto, the base portion having a circular opening therethrough for the passage of wires, said securing means including a service fitting adapter secured to the collar and extending upwardly therefrom, a clamping plate fitted over the end of the adapter remote from the duct and having a planular portion overlying the base portion and clamping the base portion to a floor surface, means securing the clamping plate to the adapter, a plurality of circumferentially closely spaced slots about the periphery of the opening in the base portion said slots being substantially equal and the clamping plate having a tang angularly disposed with resPect to the plane of the planular portion and received in a selected one of said slots to prevent relative rotation between the clamping plate and the base portion.

Claim 9

An underfloor wiring duct as claimed in claim 6 wherein the upstanding collar is formed integrally with the duct.

Claim 10

An underfloor duct as claimed in claim 6 wherein the adapter has an upper collar portion and an oblong base defining an upwardly directed annular rim therebetween, a pair of diametrically opposed openings in the rim, and said base portion of the adapter being fixedly disposed within the access opening.

Claim 11

An underfloor duct as claimed in claim 8 wherein the clamping plate has a hole therethrough for receiving said upper collar portion of the adapter and a lip portion disposed around the periphery of said hole, said clamping plate being invertible to accommodate variations in the thickness of concrete in which said duct may be embedded, said lip portion extending through the opening in said base portion in a position of the clamping plate in which said lip portion extends downwardly toward said duct, and said tang is one of two tangs receivable respectively in selected ones of said slots.

Claim 12

An underfloor duct as claimed in claim 9 wherein one tang extends away from the body of clamping plate in the direction of the lip portion and the other tang extends in the opposite direction.

Claim 13

An underfloor duct as claimed in claim 10 wherein the clamping plate has two pairs of openings therethrough, two screws are received in a selected pair of the opening in the clamping plate depending on whether said lip is extending upwardly or downwardly, said screws being threaded into the holes in the rim of the adapter.