Patent ID: 7340875

Claim:
Safety apparatus for a tool driven by a motor, comprising: a) a housing at least partially enclosing and having a cover at least partially covering the tool on at least the top thereof, said housing being movable over a ground surface; b) a ground-engaging member having a front portion, and disposed to follow the ground surface as said housing moves over the ground surface, said ground-engaging member front portion being pivotally connected to said housing; c) a sensor for measuring a distance said ground-engaging member moves relative to said housing; and d) means controlled by the sensor for stopping the motor when said ground-engaging member moves a predetermined distance relative to said housing; e) wherein said housing has a front and said ground-engaging member is pivotally connected to said housing front and is movable relative to the tool; f) wherein said ground-engaging member has a rear portion having a slot for allowing said ground-engaging member to move relative to said housing; g) wherein said means for stopping the motor is a shut-off valve; h) wherein said sensor is linked to a shaft extending from said shut-off valve and that is rotatable to activate said shut-off valve when said ground-engaging member moves a predetermined distance relative to said housing; and i) wherein said sensor has a yoke connected to an end of said shaft, said yoke being biased in an operating orientation and being rotatable to initiate said means for stopping the motor.