Lever chain adjuster for a chain saw

• US 6,694,623 B1
• Filed: 06/06/2002
• Issued: 02/24/2004
• Est. Priority Date: 06/06/2002
• Status: Expired due to Fees

• Current Assignee: Michael W. Haughey
• Original Assignee: Michael W. Haughey
• Inventors: Haughey, Michael W.
• Primary Examiner(s): Watts, Douglas D.
• Application Number:
  US10/164,251
• Time in Patent Office: 628 Days
• Field of Search: 303/86, 303/85, 303/83, 838/16
• US Class Current: 30/386
• CPC Class Codes: B27B 17/14 Arrangements for stretching the chain saw

Abstract

A cam lever arrangement is provided which permits the loosening and tightening of the chain on the chain saw blade tool with a simple lever motion. The lever arrangement is connected to the motor housing cover door. Opening the door automatically loosens the chain. Closing the door automatically tightens the chain. Precision adjustments to tension are easily made in the cam lever arrangement by hand manipulation of a turnbuckle which is free from pressure when the lever is in the release position.

Claims

1. A lever chain adjuster for a chain saw having a motor housing, an elongated, flat, plate-like chain saw blade, and an endless chain with cutting teeth, said chain extending around a peripheral edge of said elongated flat blade, said chain extending in a continuous, endless loop, said chain having a proximal end extending around a sprocket gear that engages the chain and causes it to rotate around said peripheral edge of the elongated flat blade when the sprocket gear is rotated, said sprocket gear being attached to an output shaft of a motor means housed within said motor housing, comprising:

said elongated flat blade having a proximal end portion and a distal end potion, said ends defining a horizontal, longitudinal axis, said elongated flat blade proximal end portion being secured to the motor housing, said elongated flat blade having an outer surface and an inner surface, said surfaces interconnected by a peripheral edge, said elongated flat blade surfaces lying in parallel vertical planes, said inner surface being defined as that elongated flat blade surface abutting the motor housing, said elongated flat blade having an elongated slot formed through the elongated flat blade proximal end portion, said slot having a longitudinal axis coincident with the longitudinal axis of the elongated flat blade, said elongated flat blade proximal end portion having a plurality of threaded holes formed therein;

a pair of externally threaded post members, a proximal post member and a distal post member, secured to the motor housing and extending through said elongated flat blade elongated slot, said proximal post member being shortened so that no portion of the proximal post member protrudes through said elongated flat blade elongated slot;

a turnbuckle assembly having a holding plate subassembly connected to said elongated flat blade proximal end portion threaded holes and a turnbuckle;

a cam assembly with a base plate, said turnbuckle interconnecting the turnbuckle assembly with the cam assembly; and

a removable cover attached to said cam assembly adapted for covering the elongated flat blade proximal end and chain proximal end.

2. A lever chain adjuster as recited in claim 1, wherein said holding plate subassembly is comprised of:

a flat holding plate with a plurality of holes formed therethrough, said holding plate being connected to the elongated flat blade outer surface by a plurality of fasteners inserted into the holding plate hole and engaging the elongated flat blade threaded holes;

a pivot element attached to the holding plate;

a screw socket element interconnected by said pivot element with said holding plate, said screw socket element having a central, round aperture formed therein; and

an elongated threaded screw inserted into said aperture, wherein said threaded screw extends forwardly in a distal direction generally parallel to the longitudinal axis of the flat blade, said threaded screw adapted to threadingly engage said turnbuckle.

3. A lever chain adjuster as recited in claim 2, wherein:

said base plate has an outer surface, an inner surface, a proximal end, a distal end, and two opposing, parallel sides, said proximal end and distal end defining a base plate longitudinal axis, said base plate having an aperture formed therein, at a selected position along the central longitudinal axis of the base plate, said base plate proximal end having a stabilizer tab formed thereon, said stabilizer tab protruding at an angle past the base plate inner surface, said base plate distal end having a distal end flange formed thereon, said distal end flange extending past the base plate outer surface at an approximate 90°

angle to the plate outer surface, said base plate sides each having a side flange formed thereon, said side flanges extending past the base plate outer surface at an approximate 90°

angle to the plate outer surface, said base plate adapted to being set onto the flat blade outer surface wherein said base plate aperture is adapted to fit over said distal post member, said base plate longitudinal axis being coincident with the longitudinal axis of the elongated flat blade, said base plate being positioned so that the base plate proximal end is oriented toward the flat blade proximal end, and the base plate distal end is oriented toward the flat blade distal end, said base plate tab being adapted to fit into the elongated flat blade elongated slot, said base plate inner surface being that surface positioned against the flat blade outer surface.

4. A lever chain adjuster as recited in claim 3, wherein:

the turnbuckle is comprised of a cylindrical body having a proximal end and a distal end, said proximal end and distal end defining a turnbuckle longitudinal axis, said turnbuckle longitudinal axis being parallel to said elongated flat blade longitudinal axis, said turnbuckle having a central, longitudinal, threaded aperture formed therein and extending from said proximal end to said distal end, wherein said holding plate subassembly threaded screw is adapted to engage the turnbuckle threaded aperture entering first at the turnbuckle proximal end, said turnbuckle cylindrical body distal end terminating in a round retaining end cap.

5. A lever chain adjuster as recited in claim 4, further comprising a U-shaped bracket adapted to interconnect the turnbuckle assembly with the cam assembly, said U-shaped bracket comprising:

two parallel elongated members, each having a free end and an opposite end joined to a transverse cross member, each elongated member'"'"'s two ends defining a longitudinal axis of each member, said elongated member longitudinal axis being normally parallel to the flat blade longitudinal axis, each elongated member having a lateral aperture formed therein near to said member free end, each said lateral aperture having a central axis parallel to the cross member; and

said transverse cross member interconnecting said two parallel elongated members, said cross member having a central aperture formed therein, said cross member central aperture adapted to receive the turnbuckle cylindrical body wherein the turnbuckle cylindrical body distal end cap has a diameter greater than the cross member central aperture, said turnbuckle cylindrical body distal end round retaining end cap being positioned on one side of the cross member opposite a cross member side facing the a substantial portion of the turnbuckle, said turnbuckle cylindrical body distal end round retaining end cap being on the same cross member side as the two parallel elongated members.

6. A lever chain adjuster as recited in claim 5, wherein said cam assembly is comprised of:

two, generally parallel, elongated cam levers, each said cam lever having two ends, a cam end and a lever end, said ends defining a longitudinal axis for each cam lever, each said cam lever having an elongated camming edge, an opposite engagement edge, and two flat, opposing interconnecting sides, each said cam lever having two lateral apertures formed therein along the cam lever longitudinal axis, extending through the interconnecting sides, a first aperture near to the cam end and a second aperture a specified longitudinal distance from the first aperture;

a pivot subassembly interconnecting said cam levers, said pivot subassembly being comprised of a pivot ring in a rectangular holding plate, said pivot ring adapted to fit over the distal post member;

wherein the U-shaped bracket is attached to the cam assembly by a fastener inserted through each cam lever first aperture into each U-shaped bracket elongated member lateral aperture.

7. A lever chain adjuster as recited in claim 6, wherein:

the holding plate has two opposite, lateral, small arms, each extending through a cam lever second aperture;

wherein said holding plate is held securely to the distal post member by a threaded nut and lock-washer engaging said distal post member.

8. A lever chain adjuster as recited in claim 7, wherein:

the removable cover has an outside surface, inside surface, front, rear, top and bottom, said cover front being a part of the cover closest to the flat blade distal end when the cover is closed over the flat blade proximal end and chain, said cover inside surface having two sets of holding rails, said rails being adapted to slide over the cam levers, slidably holding the cam lever engagement edges adjacent the cover inside surface, said inside surface having an attached push block.

9. A lever chain adjuster as recited in claim 8, wherein said cam assembly is further comprised of:

a plate interconnecting the parallel lever sides, said plate extending centrally a predetermined distance toward the lever cam ends and lever ends, said plate having a central opening formed therein, said central opening having a longitudinal axis parallel to the longitudinal axes of the cam levers, said plate has an exterior surface and an interior surface, said exterior surface being adjacent the cam lever engagement edges and said interior surface being adjacent the cam lever camming edges;

a spring-loaded L-shaped rod secured to the plate interior surface and positioned so that a rod 90°

end protrudes through the central opening, said rod having an opposite end of the rod terminating in a latch-hook bending away from the plate interior surface, said latch-hook adapted to engage a latching bar attached to the motor housing adjacent the sprocket gear.

10. A lever chain adjuster as recited in claim 9, wherein:

said removable cover inside surface push block is adapted to engage and move the rod 90°

end when the cover is moved rearward, thereby moving the latch-hook rearward and releasing the latching bar.

11. A lever chain adjuster as recited in claim 10, wherein:

said turnbuckle cylindrical body has a textured external surface.

12. A lever chain adjuster as recited in claim 11, wherein:

the elongated camming edge has an irregular, curvilinear cam surface formed near to the cam end.

13. A lever chain adjuster as recited in claim 5, wherein said cam assembly is comprised of:

two, generally parallel, elongated cam levers, each said cam lever having two ends, a cam end and a lever end, said ends defining a longitudinal axis for each cam lever, each said cam lever having an elongated camming edge, an opposite engagement edge, and two flat, opposing interconnecting sides, each said cam lever having two lateral apertures formed therein along the cam lever longitudinal axis, extending through the interconnecting sides, a first aperture near to the cam end and a second aperture a specified longitudinal distance from the first aperture;

two side holes in said distal post member;

a pivot subassembly interconnecting said cam levers, said pivot subassembly being comprised of an overlapping sleeve with two releasable, internal spring-forced locking pins adapted to fit over said distal post member and inserting said locking pins into said distal post member side holes, said sleeve having two opposite, lateral, external, small arms, each extending through a cam lever second aperture;

wherein the U-shaped bracket is attached to the cam assembly by a fastener inserted through each cam lever first aperture into each U-shaped bracket elongated member lateral aperture.

14. A lever chain adjuster as recited in claim 13, wherein:

the removable cover has an outside surface, inside surface, front, rear, top and bottom, said cover front being a part of the cover closest to the flat blade distal end when the cover is closed over the flat blade proximal end and chain, said cover inside surface having two sets of holding rails, said rails being adapted to slide over the cam levers, slidably holding the cam lever engagement edges adjacent the cover inside surface, said inside surface having an attached push block.

15. A lever chain adjuster as recited in claim 14, wherein said cam assembly is further comprised of:

a plate interconnecting the parallel lever sides, said plate extending centrally a predetermined distance toward the lever cam ends and lever ends, said plate having a central opening formed therein, said central opening having a longitudinal axis parallel to the longitudinal axes of the cam levers, said plate has an exterior surface and an interior surface, said exterior surface being adjacent the cam lever engagement edges and said interior surface being adjacent the cam lever camming edges;

a spring-loaded L-shaped rod secured to the plate interior surface and positioned so that a rod 90°

end protrudes through the central opening, said rod having an opposite end of the rod terminating in a latch-hook bending away from the plate interior surface, said latch-hook adapted to engage a latching bar attached to the motor housing adjacent the sprocket gear.

16. A lever chain adjuster as recited in claim 15, wherein:

said removable cover inside surface push block is adapted to engage and move the rod 90°

end when the cover is moved rearward, thereby moving the latch-hook rearward and releasing the latching bar.

17. A lever chain adjuster as recited in claim 16, wherein:

said turnbuckle cylindrical body has a textured external surface.

18. A lever chain adjuster as recited in claim 17, wherein:

the elongated camming edge has an irregular, curvilinear cam surface formed near to the cam end.