Compressible cover fixing device for use on support structure, has cup point presenting rounded base having tangent in axial plane, where tangent makes angle between specific values with respect to axis of cup point

摘要

The device has a rectangular plate (8) with a cup point (9), whose base is provided with an axial boring (O) and an auto-perforation and/or self-tapping fixation screw (1) including an under-head thread (4). A fillet of the thread presents a shapeless form and includes a surface at a head side, where the surface is inclined along a slope equal to 15 degree at a radial plane of the cup point. The cup point presents a rounded base having a tangent in an axial plane, and houses a screw head (5), where the tangent makes an angle between 30 and 60 degrees with respect to an axis of the cup point.