| 摘要 |
A lightweight self-insulating composite hand tool such as a screwdriver has a tool shank of electrically insulative material molded to and about a tip shank of a tool tip, having a working end and an integral tip shank. A mechanical interlock coupling is molded into the tip shank to resist axial tensile and compressive stress and torsional stress. A premolded replaceable elastomeric cover is slipped onto the hand tool and about the periphery of the molded tool shank. The working end of the tool tip includes a circumferential groove which receives a snap fitting bead of the replaceable elastomeric cover. The molded tool shank may be a braided composite of non-electrically conducting reinforcing filaments embedded within a settable matrix such as resin or epoxy. The tip shank is provided with an annular recess which flares rearwardly at a slight retention angle to retain the braided filaments and the settable matrix end of the composite tool shank on the tool tip shank. A molded core or mandrel having a conical front end is wedged into a conical bore within the tip shank, about which the filaments are wound in forming the braided composite tool shank. The periphery of the tool tip shank at the annular recess is provided with polygonal facets providing a mechanical interlock between the braided composite and the tool tip which resists axial tensile and compressive forces and torsional forces. A thermoplastic handle as adhesively fixed to the rear end of the braided composite tool shank. |
