Lead propelling mechanism for a mechanical pencil
AssigneeKotobuki & Co., Ltd.
InventorHidehei Kageyama
Life of this patent
Estimating the term…
Abstract
A lead propelling mechanism for a mechanical pencil includes a lead chuck, a ring fitted loosely about the chuck for tightening its head, a sleeve having a front end contacting the ring, and an elastic member having a front end bearing on the front end of the sleeve and a rear end held by a shoulder formed on the outer surface of the chuck adjacent to its rear end. The mechanism is very easy to assemble and join to a lead holding tube in the pencil. The rear end of the elastic member bears against an adjacent end of the tube to urge the ring to tighten the head of the chuck, when the chuck is inserted into the tube.
Claims6
A lead propelling mechanism for a mechanical pencil comprising:
- a lead chuck having a front end defining its head and a rear end, said chuck having on its outer peripheral surface a groove including a shoulder located adjacent to said rear end thereof;
- a ring fitted loosely about said chuck for tightening said head thereof;
- a sleeve having a front end contacting said ring;
- and
- a coiled spring having a front end bearing on said front end of said sleeve and a rear end held by said shoulder, said rear end of said spring being adapted to bear against an adjacent end of a lead holding tube to urge said ring to tighten said head;
- and
- said spring having a smaller diameter at its rear end portion defining said rear end, and a larger substantially uniform diameter in the remaining portion thereof, solely said smaller diameter rear end portion being contained within said groove.
Dependencies are inferred from the claim text.