Chain saw tensioning mechanism
AssigneeJT Investments
InventorJames R. Talberg
Life of this patent
Estimating the term…
Abstract
A mechanism for tensioning the chain of a chain saw. The apparatus includes a cutting bar around which the chain extends. The cutting bar has a base portion mounted to an operating housing of the chain saw, and a distal portion carried by the base portion at an end thereof remote from the housing. The distal portion of the cutting bar is disposed for sliding extension relative to the base portion of the cutting bar. The distal portion of the cutting bar mounts a sprocket, around which the chain passes, at an outer end thereof. The sprocket is disposed for rotation about an axis. Structure is included to effect extension of the distal portion of the cutting bar relative to the base portion thereof. Tensioning of the chain saw is, thereby, accomplished.
Claims10
A chain saw with means for tensioning a chain of the chain saw, the chain saw comprising:
- (a) a cutting bar around which the chain extends, said cutting bar including a base portion mounted to an operating housing of the chain saw and a distal portion carried by said base portion at an end thereof remote from the operating housing, said distal portion being disposed, relative to said base portion, for sliding extension relative thereto, said base portion of said cutting bar having a channel formed therewithin and an access port communicating with said channel proximate an inner end thereof, and wherein said distal portion of said cutting bar includes an inwardly extending piston received within said channel for telescoping movement therealong, wherein fluid can be injected, through said access port, into a plenum defined within said channel inwardly of said position to effect extension of said distal portion of said cutting bar relative to said base portion of said cutting bar;
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- (b) a sprocket, around which the chain passes, mounted at an outer end of said distal portion of said cutting bar and disposed for rotation about an axis.
A chain saw with means for tensioning a chain of the chain saw, the chain saw comprising:
- (a) a cutting bar around which the chain extends, said cutting bar including a base portion mounted to an operating housing of the chain saw and a distal portion carried by said base portion at an end thereof remote from the operating housing, said distal portion being disposed, relative to said base portion, for sliding extension relative thereto, said base portion of said cutting bar including a piston received within an axially-disposed channel formed in said base portion of said cutting bar;
- (b) a sprocket, around which the chain passes, mounted at an outer end of said distal portion of said cutting bar and disposed for rotation about an axis;
- and
- (c) a cam having an outer surface in engagement with an inner edge of said piston, said cam being disposed for rotation about an axis generally transverse to an intended direction of extension of said distal portion of said cutting bar so that, as said cam is rotated about said axis in a first direction, said piston will be urged outwardly.
A chain saw with means for tensioning a chain of the chain saw, the chain saw comprising:
- (a) a cutting bar around which the chain extends, said cutting bar including a base portion mounted to an operating housing of the chain saw and a distal portion carried by said base portion at an end thereof remote from the operating housing, said distal portion being disposed, relative to said base portion, for sliding extension relative thereto, said base portion of said cutting bar including a piston received within an axially-disposed channel formed in said base portion of said cutting bar;
- (b) a sprocket, around which the chain passes, mounted at an outer end of said distal portion of said cutting bar and disposed for rotation about an axis;
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- (c) a spring in engagement, at one end thereof, with a base of said channel and, at another end thereof, with an inner edge of said piston;
- (d) wherein upper and lower edges of said piston slope inwardly toward a center of said channel, and further comprising means for inhibiting withdrawal of said piston within said channel during operation of the chain saw.
Dependencies are inferred from the claim text.