Ratch′et-punch.
A punch operated by a screw, which is rotated by a lever having a pawl connection [1883] to a ratchet b on the shank of the screw. The crank on the upper end of the screw-shank is for a quick motion, to bring the punch down to its work or to raise it after the hole is made.Ratchet-punch. |
Ratchet-wheel. |