| 摘要 |
Improvements to the construction of metal brackets with screw for the clampi ng or tightening thereof, the vertices of the extremities of the two arms of th e front cross-bar at the body-tunnel entrance are enlarged, and a space is provided for the housing thereof into the screw body, with concentric bearin g flange and double clamping tailpiece of the two ends of the metal strip coil ed from the tunnel base being substituted by a transverse monotailpiece which i s rabated to the opposite side, with a threaded tongue for clasping purposes, and one of the extremities of the strip having two juxtaposed drawn pieces, one in the upper surface and the other one in the lower surface of crimping with the edge of the transverse monotailpiece, the upper one impeding the excessive elevation of the proper extremity. |
