Writing instrument, esp. propelling pencil - has lead enclosed by gripper inside guide operated by rotary cam mechanism

摘要

The instrument has a lead (6) in a moving guide (12) equipped with a gripper (35).The lead guide is advanced and retracted inside the barrel of the instrument by means of a rotary cam mechanism in the form of a bush (11) with an angled slot (19) which receives a peg (17). The cam guide slot is made with two more or less straight sections which correspond to the advancement of the gripper and the lead and a bend between them for the engagement or disengagement of the gripper. The two straight sections of the slot are set at angles which are designed to maintain a smooth movement of the guide and lead as they are advanced and retracted.In a variant of the design, the instrument can have a number of cams which operate in sequence. ADVANTAGE - Operates smoothly and with reduced effort.