| 摘要 |
A paper punch includes a ratchet assembly received in each of the frames on a base. A handle assembly is connected to the frames. The ratchet assembly includes ratchet wheels co-rotatably connected to the driving gear which drives a rack to lower the punch head. The handle assembly includes a driving pawl which is engaged with two teeth in sequence of the ratchet wheels to proceed the punching action, and a return pawl which rotates the ratchet wheels in opposite direction after the punching action is finished. The handle assembly is repeatedly operated while the punch head is kept in the pile of paper sheets to be punched. The angular movement of each movement of the handle assembly is less than 90 degrees.
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