Lawn mower having adjustable air vents

Abstract

Adjustable ventilation apparatus for a lawn mower, adapted to allow adjustment of the airflow rate into the cutting deck to maximize operation of the lawn mower under various operating conditions. In one embodiment, the apparatus comprises a ring disposed intermediate the engine and cutting deck of a walk behind mower, having a plurality of radial openings formed therethrough. An annular cover is provided encircling the ring, with the cover having a like number of openings formed in the peripheral wall thereof. Rotational movement of the cover relative to the ring moves the openings therein into and out of alignment with the openings in the ring, thereby defining open and closed positions for the vent, respectively. The cover may also be moved to a plurality of positions intermediate fully open and fully closed to provide the appropriate airflow into the cutting deck. An alternative embodiment provides a stationary outer cover and a rotatable ring, each having a plurality of longitudinal slots and radial openings formed therein. Selective positioning of the ring relative to the cover determines the opening size formed through the slots and the consequential airflow through the top of the cutting deck. The ring includes a handle extending therefrom for moving and positioning the ring, the handle having a wire stop attached thereto engageable in a serrated portion of the stationary cover to retain the ring in its desired position and prevent inadvertent movement thereof. A third embodiment is specially adapted for use on riding mowers having a pair of cutting blades, comprising two stationary portions fixed to the cutting deck and two corresponding outer rotatable rings interconnected for synchronized movement.