Abstract: An intertial-manual actuating chain brake for a chain saw in which a mechanical integrator distinguishes between relatively long duration accelerations developed by a "kickback" producing impulse and normal operating accelerations associated with operational and vibratory forces. Occurrence of a "kickback" impulse, developing a force of required magnitude, direction, and duration causes a spring-mass accelerometer to change from a brake released to a brake applied condition, applying a braking torque to the saw chain. The accelerometer utilizes a pivotable hand guard as the actuating means. The hand guard also provides for manual operation. The hand guard is comprised of a housing and an inertia weight that is connected to the housing. The weight and type of inertia weight can be selected to provide the brake applied condition for a predetermined movement of the chain saw or for a predetermined type of chain saw. The inertia weight can be adjusted to adjust the accelerometer.

Abstract: A chain saw having a resilient deflectable rear handle. The rear handle is connected to a housing of the chain saw at a first end and has a second end that is cantilevered. A portion of the housing is suitably sized, shaped and positioned relative to the rear handle second end to form a deflection overload constraint to prevent the rear handle from deflecting too much. The cantilevered configuration of the rear handle and its deflectability allow vibrations generated during operation of the chain saw to be reduced at an operator's grasping location on the rear handle.

Abstract: A carburetor and chain oiling assembly and method of manufacturing the same for use in a chain saw. The assembly generally comprises a carburetor section, an oil pump section and a cover connecting the two sections. The cover can connect the oil pump section to the carburetor section forming a cover for a carburetor fuel diaphragm and a working chamber with an oil pump diaphragm. The cover has a gas conduit between the carburetor housing and the working chamber such that gas pulses from an engine crankcase can be supplied to the working chamber to operably move the oil pump diaphragm to provide a continuous and automatic metered flow of oil to a saw chain.