Patent ID: 7367174

Claim:
A lawn mower, which comprises: (a) a cutting deck supported for movement over the ground, wherein the cutting deck has a width that extends between opposite left and right lateral sides thereof; (b) a single, downwardly facing cutting chamber on the cutting deck, the cutting chamber having a top wall, a substantially circular sidewall extending vertically downwardly from the top wall, and an open bottom circumscribed by the sidewall, wherein the substantially circular sidewall is generally centered on the cutting deck such that the single cutting chamber spans substantially across the width of the cutting deck with opposite side portions of the sidewall being located adjacent the left and right sides of the cutting deck; (c) a rotatable cutting blade within the cutting chamber for cutting grass, wherein the cutting blade rotates about a substantially vertical axis of rotation with the axis of rotation being substantially centered within the substantially circular sidewall of the cutting chamber; (d) a generally rearwardly extending exit tunnel asymmetrically located on the cutting deck with the exit tunnel being located closer to one lateral side of the cutting deck than the other lateral side of the cutting deck, wherein a front end of the exit tunnel overlies at least a portion of the cutting chamber on the cutting deck for receiving grass clippings from the cutting chamber in a discharge/collection mode of operation and for conducting such clippings to a discharge opening on the cutting deck, wherein the discharge opening in the discharge/collection mode of operation is separate and distinct from the open bottom of the cutting chamber through which the grass clippings exit in a mulching mode of operation; and (e) a pivotal mulch door located within the exit tunnel, the pivotal mulch door having an open position and a closed position, wherein the pivotal mulch door comprises both a first portion forming a portion of the top wall of the cutting chamber and a second portion forming a portion of the sidewall of the cutting chamber when the door is in the closed position, the second portion of the mulch door extending vertically downwardly from the first portion of the mulch door in the same manner that the sidewall extends vertically downwardly from the top wall, wherein the mulch door is selectively pivotal relative to the cutting chamber between the open position in the discharge/collection mode of operation and a closed position in the mulching mode of operation.