| 摘要 |
An automatic pencil employing axial movement of a lead piece guide and a lead piece chucking mechanism. After a length of protruding lead rod is used up, the lead piece guide is caused to retract in the same amount as the wearing away of the lead rod. By pressing the tip of the lead rod against another object, the lead rod is caused to move back with the chucking mechanism. After the rod is retracted until the tip aligns with the tip of the guide, the rod and lead piece guide will be moved back. The rod will then advance when the holder is moved away from the object while the lead piece guide will be left in the retracted position due to a large friction between the friction member and the guide means. By this operation, the rod is protruded from the guide at substantially equal length to the stroke of the retracting movement. In other words, the guide is moved back at each time when the rod moves back and forward to allow the rod to protrude by a constant length which is irrespective to that which has previously protruded.
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