| 摘要 |
A tamper-proof screw assembly is made up of three basic parts, two of which are coupled together. First, there is provided a screw having a flat head with a center tapped opening and an annular array of teeth formed in its surface surrounding the tapped opening. A second member constitutes a torquing member with a flat bottom and central bore passing completely through the member. An annular array of teeth is formed in the flat bottom in a position to register with the first mentioned annular array of teeth. A third member serves to apply an axial force between the torquing member and the screw head to hold the teeth respectively in engagement with each other so that torque can be transferred to the screw. This third axial force applying member simply comprises a shaft with a threaded end portion receivable in the tapped opening and an enlarged head overlying the torquing member so that when threaded down into the tapped opening in the screw head, the torquing member when rotated will transfer torque to the screw head. Removal of the axial force applying member and torquing member leaves exposed only the flat screw head and because of the sloping teeth, it is not possible to remove the screw without the special second and third parts of the assembly.
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