Patent ID: 6186306
Filing Date: 2001-02-13
Classification: E04F,E05F,E05Y

Abstract:
A generally vertically extending chute terminating at an open end bounded by a frame mounted to a support surface and a chute door having a front surface, side surfaces extending from the front surface and a door pivot at the bottom of the front surface journalled at the frame whereby door opening, assisted by door gravity, results by rotation of the door front surface about the door pivot from a closed position, whereat the front surface is generally adjacent and closes the chute's open end while the side surfaces extend into the chute, to an open position, whereat the front surface is at least 45.degree. displaced from its closed position and the side surfaces are out of the chute, the improvement comprising:a first linkage arrangement adjacent one of the door side surfaces including a door pivot link extending from the door pivot, a pivotable variable length electric actuator link, and a plurality of interconnecting links pivotably connected to the door pivot and actuator link; an electric motor for varying the length of the electric actuator link which causes the chute door to rotate from an open to a closed position;a second linkage arrangement adjacent said one of the door side surfaces resisting door opening and for assisting door closing, the second linkage arrangement including a variable length spring actuator link, the spring actuator link having an increased length when the chute door is opened and a decreased length when the chute door is closed and an air spring controlling the length of the spring actuator link by exerting a force tending to keep the spring actuation link at a decreased length; and,a manually operated switch for actuating the motor to open and close the chute door wherein said second linkage arrangement includes an intermediate link pivotably secured to one end of the spring actuator link and the door pivot link, the other end of the spring actuator link is fixed to a front panel for permitting expansion and contraction of the spring actuator link in one direction.