CPC B43K 24/06 (2013.01) [B43K 29/02 (2013.01)] | 17 Claims |
1. A writing instrument comprising a body extending along an axis, the body having a first end and a second end opposed to the first end along the axis, the first end being provided with a writing tip and with an eraser, the writing instrument further comprising a first helical cam propelling mechanism configured to move the writing tip along the axis between a retracted position and a protruded position and a second helical cam propelling mechanism configured to move the eraser along the axis between a retracted position and a protruded position, the first helical cam propelling mechanism comprising a first cam follower and a first helical cam, the second helical cam propelling mechanism comprising a second cam follower and a second helical cam, each of the first cam follower, the first helical cam, the second cam follower and the second helical cam being provided on distinct elements, wherein the first helical cam propelling mechanism is configured to retract the writing tip to an intermediate position between the protruded position and the retracted position, when the eraser is moved from the retracted position to the protruded position.
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