Abstract: A machine control system for sensing an obstruction in the path of a machine tool and preventing movement of the tool along its path while requiring operator initiation for each machine tool actuation. A sensor is mounted on a movable support rod and adjustably positioned to move along a path coaxial with the path of the tool in order to sense any obstruction in a work area. The movable support rod is constructed to allow gravity fall of the sensor into the work area and to cause actuation of a switching circuit allowing machine tool movement if no obstructions are sensed. A spring-biased arm coupled to a rotary solenoid retains the movable support rod in a rest position. Upon actuation, the solenoid rotates the arm so that gravity causes the support rod to fall and the sensor to move into the work area. A normally closed switch is positioned to open in response to the end stroke of machine tool movement.

Abstract: An improved machine control for sensing an obstruction in the path of a machine tool and preventing movement of the tool along its path. A sensor is mounted on a movable support rod and adjustably positioned to move along a path coaxial with the path of the tool in order to sense any obstruction in a work area. The movable support rod is constructed to allow gravity fall of the sensor into the work area and to cause actuation of a switching circuit allowing machine tool movement if no obstructions are sensed. A spring-biased arm coupled to a rotary solenoid retains the movable support rod in a rest position. Upon actuation, the solenoid rotates the arm so that gravity causes the support rod to fall and the sensor to move into the work area. The elements of the machine control are mounted to a plate which may be removably attached to various types of machines.