KNOCK TYPE WRITING INSTRUMENT

PROBLEM TO BE SOLVED: To provide a knock type writing instrument that can easily protrude and retract a member attached to a rear end by a knock operation with one hand.SOLUTION: When a knock mechanism is at the farthest rear end position, a writing instrument tip end 13a is retracted in a cylinder 17 as well as a rear end accessory 20 is covered with a rear end covering member 16. When the knock mechanism is latched at a middle position by a knock operation, the writing instrument tip end 13a is retracted in the cylinder 17, however, the rear end accessary 20 is exposed at the rear end of the cylinder 17. When the knock mechanism is at the farthest front end position by the knock operation, the writing instrument tip end 13a is protruded from the tip end of the cylinder 17 as well as the rear end accessary 20 is exposed at the rear end of the cylinder 17.