| 摘要 |
A frame formed by frame sections joined end to end; each frame section having an elongated channel with a rear wall, spaced apart lips opposite the rear wall and defining a longitudinally directed slot and a side wall joining inner edges of each of the lips to a different edge of the rear wall. Securing adjacent pairs of the sections is a bracket having a pair of legs disposed at an angle substantially identical to the angle made by the frame sections, the legs fitting within the channels of said frame sections at their corner junction and having a width greater than the width of the slots so as to retain the bracket within the channels. A screw with an externally threaded shank is received by a threaded hole in each bracket leg. Each has an outer end adapted to accommodate a tool for producing axial rotation of the screw so as to force outer surface portions of the legs into engagement with inner surface portions of the lips and an inner end defining a contact surface engaging the rear wall of the channel and having an area substantially larger than the cross-sectional area of the shank.
|
