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US 2014/0305273 A1Published application
Chain saw chain containment device
OwnerKenneth J. Thomseninventor
Life of this patent
Estimating the term…
Abstract
A device for deflecting a detached cutting chain off the drive sprocket of a chain saw in order to deenergize and arrest it. A ramp provides a surface disposed below the chain guide bar, which surface is oblique with respect to the chain guide bar, slightly below a lower edge of the chain guide bar and obliquely angled with respect to a plane that contains the exterior surface of the chain guide bar, and distal to the drive sprocket. Sliding engagement of a detached cutting chain with the oblique surface moves the cutting chain exteriorly away from the chain guide bar and off the drive sprocket. A chain catcher is also provided to arrest the detached cutting chain and/or chain shot portions thereof.
Claims18
A chain containment device for use in a chain saw, said chain saw including
- a chain bar mount, said chain bar mount comprising a proximal ring and a distal base, said chain bar mount having an interior surface and an opposite, exterior surface;
- a motor assembly attached to the interior surface of the ring portion, said motor assembly including a motor drive shaft that extends exteriorly through the ring portion;
- a drive sprocket in driven engagement with the motor drive shaft for rotation therewith about the drive shaft axis whenever the motor is energized, said drive sprocket protruding exteriorly from the ring;
- a chain guide bar that extends from a proximal end portion to an opposite, distal end portion in a direction normal to the motor drive shaft axis, the proximal end portion being attached to the exterior surface of the base of the chain bar mount, said chain guide bar having a straight, upper edge and an opposite, straight, lower edge joined by a curved, distal edge and having a peripheral groove that extends continuously along said edges;
- a saw chain tensioner attached to an exterior surface of the proximal end portion of the chain guide bar and to the base of the chain bar mount by fasteners, said tensioner including means for moving the chain guide bar proximally and distally with respect to the chain bar mount;
- and
- a closed-loop, cutting chain looped around the drive sprocket and the peripheral groove of the chain guide bar;
- said device comprising:
- deflector means for deflecting, during operation of the chain saw, a detached or broken cutting chain exteriorly away from the drive sprocket to thereby deneergize the cutting chain;
- wherein said deflector means is disposed below the chain guide bar and distal to the drive sprocket, and obliquely crosses a plane that contains the chain guide bar from a distance slightly interior to a plane that contains the interior surface of the chain guide bar to a distance exterior to a plane that contains the exterior surface of the chain guide bar;
- and
- said deflector means includes
- ramp means having an exterior surface that extends proximally and exteriorly at an oblique angle with respect to a plane that contains the exterior surface of the chain guide bar;
- and
- means for attaching the ramp means to the chain saw;
- and
- chain catcher means for catching and arresting a detached cutting chain after it has been deflected exteriorly away from the drive sprocket, said means being attached to the chain saw and spaced apart exteriorly from the proximal ring of the chain bar mount.
14 more elements
A method for deflecting a detached chain saw cutting chain from the chain saw drive sprocket during operation of the chain saw, said chain saw including
- a chain bar mount, said chain bar mount comprising a proximal ring and a distal base, said chain bar mount having an interior surface and an opposite, exterior surface;
- a motor assembly attached to the interior surface of the ring portion, said motor assembly including a motor drive shaft that extends exteriorly through the ring portion;
- a drive sprocket in driven engagement with the motor drive shaft for rotation therewith about the drive shaft axis whenever the motor is energized, said drive sprocket protruding exteriorly from the ring;
- a chain guide bar that extends from a proximal end portion to an opposite, distal end portion in a direction normal to the motor drive shaft axis, the proximal end portion being attached to the exterior surface of the base of the chain bar mount, said chain guide bar having a straight, upper edge and an opposite, straight, lower edge joined by a curved, distal edge and having a peripheral groove that extends continuously along said edges;
- a saw chain tensioner attached to an exterior surface of the proximal end portion of the chain guide bar and to the base of the chain bar mount by fasteners, said tensioner including means for moving the chain guide bar proximally and distally with respect to the chain bar mount;
- and
- a closed-loop, cutting chain looped around the drive sprocket and the peripheral groove of the chain guide bar;
- comprising the steps of:
- (a) attaching a ramp to the chain saw, wherein
- said ramp is disposed below the chain guide bar and distal to the drive sprocket;
- an exterior surface of said ramp extends proximally, progressively, and exteriorly from an entrance surface thereof to an exit surface thereof;
- and
- the entrance surface is a slight distance interior to the plane that contains the interior surface of the chain guide bar;
- and
- (b) attaching to the chain saw chain catcher means for catching and arresting a detached cutting chain after it has been deflected exteriorly away from the drive sprocket by said ramp, said means being spaced apart exteriorly from the proximal ring of the chain bar mount.
12 more elements
Dependencies are inferred from the claim text.