| 摘要 |
An electrical pattress box 7 comprises a back panel 8 and one or more side walls 10 wherein the cross sectional area bound by the wall or walls is circular or is the shape of an area defined by two or more semi-circular areas having a rectangular area between them, the straight edges of the semi-circular areas corresponding to sides of the rectangular area. At least one peripheral flange 12 is provided with a lug 15 adjacent an aperture 16 which provides resilient movement of the cover engaging protuberance 15. A cover 17 may be provided with a hole 20 to snap onto engagement lug 15. Installation is facilitated by exclusive or predominant use of a tool for cutting circular holes. If the back box is circular then a lower portion of the side wall may be provided with integral cutting teeth providing a self-cutting pattress box. |
