| 摘要 |
A rotating arbor has a hollow interior and a forward end provided with a number of fingers which are spaced apart from adjacent fingers by longitudinally extending slits. The hollow interior and the slits are dimensioned such that a conventional concrete pin may be inserted into the arbor and be rotated by it. In one version of the apparatus, three rollers are situated side by side and a space separates each roller from an adjacent roller. A length of wire is positioned such that one of its segments extends through one space and extends to and through the aperture in the head of the concrete pin. A second segment of the wire doubles back from the concrete pin to and through the second space. As the arbor rotates, the segments of the wire twist around each other to attach them to the pin. In another version of the apparatus, the segments the wire are received in grooves formed in two blocks, one stationary and the other pivotal. As the concrete pin rotates, the pivotal block pivots to facilitate twisting of the wire segment in the pivotal block around the other wire segment. |
