摘要 |
<p>The internal combustion engine of a portable chain saw includes a liquid lubricant reservoir which is in communication with the crankcase of such engine for being pressurized thereby. A cylindrical subassembly is mounted in this reservoir and includes a spring-biased ball valve adjacent an inlet opening, which opening is normally immersed in the liquid lubricant. This subassembly includes an outlet communicating with a passageway to the cutting chain to be lubricated. When the internal combustion engine is running, the pressurized lubricant unseats the ball valve thereby automatically lubricating the cutting chain by a metered flow of lubricant past the ball valve. The cylindrical subassembly includes a piston pump which is manually actuated from a lever adjacent the control quadrant of the portable tool. Each actuation of this lever causes the ball to be unseated and a quantity of the liquid lubricant to be supplied to the cutting chain for manual lubrication before starting the internal combustion engine; when the engine is running, operation of this lever increases the flow of oil to the cutting chain.</p> |