| 摘要 |
Novelty: self-retained fixing and connection bolt devoid of a base-plug ordinarily needed for fixing or connection purposes. Constitution: The fixing element is composed of two sections (fig.1-A.E): 1) The hollow section A manufactured as an ordinary screw (fig.2, H); at the front part and close to the exit of the thread, it bears the hole (fig.2,I) wherethrough the pin passes from the exterior to the interior (fig.1, B). 2). 2) The second section (fig.3) is composed of a cylinder the diameter of which is equal to the interior diameter of the bolt and bears a threaded portion (fig.1,3.C). The next portion of this second section (fig.1,3.E) is configurated to constitute a drilling tool bearing at its end a drilling head (fig.1,3.F). Operation mode: The thread direction of the hollow bolt (fig.1,2.D) is inverse to the thread direction of the drilling tool (fig. 1,3.C). In this way, by application of the head of the screw (fig.1,2.G) to an ordinary drilling device and by selection of a screwing direction which is opposite to that of the drilling tool inside the cavity of the piece A, the user can proceed to the drilling of the desired material; once the drilling portion B is entirely inserted inside the created hole, the user can merely reverse the direction of the drilling device so that the bolt can be propelled inside the material since the thread of the drilling portion is screwed inside the cavity of the external bolt while the external thread is screwed on the drilled material to create a compact nailing. |
