Chainsaw tensioning device
AssigneeMTD Products Inc
InventorsDavid B. Fisher, Todd J. Ford
Life of this patent
Estimating the term…
Abstract
A chainsaw has a cam lever and cam assembly that can be used to adjust the tension of a guide bar in the chainsaw. Once the tension of the guide bar has been lessened, the guide bar can be moved back and forth by using a chain-tightening knob and tightening mechanism. The movement of the guide bar causes the chain to tighten or loosen on the guide bar.
Claims14
A chain-tightening device in combination with a guide bar of a chainsaw, said chain-tightening device comprising:
- an adjustable cam lever having an open position and a closed position;
- a cam having a hollow vertical opening;
- a first mounting screw connecting said cam lever to an elongated portion of said cam;
- a pivot pin inserted into said hollow vertical opening and having a hollow horizontal opening;
- a cam cup adjacent to said pivot pin and attached to said guide bar by an anchor bolt;
- a second mounting screw inserted into said hollow horizontal opening of said pivot pin;
- at least one spring in said cam cup;
- a cam follower adjacent to said at least one spring;
- a retaining ring adjacent to said cam follower;
- and
- wherein said spring applies pressure to said guide bar when said cam lever is in a first position.
A tension adjuster in combination with a guide bar for a chainsaw, said tension adjuster comprising:
- a cam cup adjacent to said guide bar, said cam cup being selectively engageable with said guide bar;
- at least one spring positioned within said cam cup;
- a cam adjacent to said cam cup;
- a pivot pin about which said cam rotates;
- and
- a cam lever to which said cam interconnects.
A tension adjuster in combination with a guide bar of a chainsaw, said tension adjuster comprising:
- a cam lever movable between a first position and a second position;
- a cam attached to said cam lever, wherein said cam rotates when said cam lever moves between said first position and said second position;
- a spring positioned between said cam and said guide bar such that when said cam rotates, said spring moves closer or farther away from said guide bar, thereby adjusting the pressure the cam exerts on the guide bar;
- a rotatable chain-tightening knob on a housing and underneath said cam lever such that said chain-tightening knob is accessible when said cam lever is moved from said first position to said second position;
- a gear within said housing that meshes with said chain-tightening knob;
- and
- a tensioning screw interacting with said gear and said guide bar, wherein rotation of said chain-tightening knob causes said guide bar to move.
Dependencies are inferred from the claim text.