Electrical wiring box arrangements

DETAILED DESCRIPTION Referring to the drawing figures, an electrical wiring box arrangement in accordance with one embodiment of the present invention is shown in FIG.
1.
An electrical wiring box 10 comprises a front-to-rear wall structure including end walls 12 and 14, side walls 16 and 18, and rear wall 20 which in combination define a chamber within the box having a forward opening for receiving an electrical wiring device such as a switch or plug receptacle (not shown).
The wall structure of wiring box 10 is provided with knock-out regions, typified by knock-out region 22.
In a preferred embodiment of the present invention, the wiring box 10 is formed of a molded resin and each knock-out region is closed by a frangible web as shown by knock-out region 22.
Prior to insertion of an electrical cable into the box chamber through a wall, the frangible web is removed to provide a knock-out aperture as shown typically by knock-out aperture 24.
In a preferred configuration of the wiring box, the knock-out regions are located in the front-to-rear wall structure of the box, immediately adjacent to the box rear wall.
For example, in the embodiment shown in FIG.
1, knock-out region 22 is located in end wall 12 immediately adjacent to rear wall 20.
Removal of the frangible web from a knock-out region situated immediately adjacent to the intersection of a front-to-rear wall and the rear wall of the box provides a knock-out aperture such as 24 which permits an electrical cable to pass through a side wall and to lie directly along the rear wall of the box.
Thus, as shown in FIG.
3, electrical cable 100 passes through knock-out aperture 26 in end wall 14 and lies flat along rear wall 20 of box 10.
The wall structure of the wiring box is further provided with one or more protrusions or ridges for gripping or otherwise engaging a non-metallic sheathed electrical cable.
In the embodiment shown in FIG.
1, the cable engaging protrusions take the form of parallel toothed ridges 28, 30 and 32 integrally molded in rear wall 20 of box 10