Mower cutting deck having operator controlled discharge opening using foot pedal control

A mower has a rotary cutting deck with a discharge opening covered by a discharge chute. A pivotal gate is placed beneath the discharge chute to pivot relative to the discharge opening between a closed position in which the gate blocks the discharge opening and an open position in which the gate opens the discharge opening, thereby providing discharge and non-discharge modes of operation respectively. A pivotal foot pedal can be depressed by the operator against the force of a biasing spring to move the gate between the closed and open positions thereof. When the gate reaches its open position corresponding to a fully depressed foot pedal, an over center linkage has reached an over center orientation in which the force of the spring now serves to lock the pivotal gate in the open position thereof. Another over center linkage also locks the pivotal gate in the closed position thereof when the foot pedal is in a non-depressed starting position.