GB173887A - Improvements in and relating to driving mechanism - Google Patents

Abstract

173,887. Igranic Electric Co., Ltd., (Cutler-Hammer Manufacturing Co.). Oct. 12, 1920. Operating clutches. - A driving motor having independently movable elements is combined with a clutch which connects one of the elements to a driven device and with means controlled by the movement of the other element for engaging and disengaging the clutch. In the form shown, an electric motor is used, having a rotor 24 and movable stator 14 which actuate, through a clutch 27, 28, a driven device in the form of an arm 12 which controls the brakes 2, 3 normally applied to an elevator or like brake drum 1 by a spring 10 and pivoted arms 4, 5. The stator swings on the rotor shaft 17 and has a projection 31 engaging, under the action of an axial spring 32 and biassing weights 26, a cam plate 30 mounted rigidly on the upstanding frame member 7 in which the shaft 17 is journaled. Loose on this shaft is a clutch member 28 integral with a sprocket wheel 16 from which a chain-drive is taken to the lower countershaft 20. Rigidly mounted on the shaft are the rotor and the other clutch member 27. The shaft 20 has a short crank-arm 19 coupled by links 21, 22 to the brake-operating lever 12, the length of the crank being such that in addition to causing a decrease in the mechanical advantage of the motor when the shaft rotates in either direction from the position shown, it causes the end of the link 21 to abut on the shaft 20 and bring the motor to rest. Starting with the brakes on under the action of the spring 10, energization of the motor rocks the stator to an extent determined bv the counterweights 26, the cam 30 thereby being caused to move the rotor and stator bodily to the right against the action of the action of the spring 32. This engages the clutch discs 27, 28 and the ensuing rotation of the rotor drives the shaft 20 through the clutch and chain gear and causes the lever 12 to separate the brake arms 4, 5. Rotation continues until the abutment of the link 21 on the shaft 20 stops the motor and the torque between the motor elements is balanced by the restoring couple due to the spring 10. The brakes are thus held off as long as the motor is energized. When it is de-energized the clutch is at once disengaged and the spring 10 reapplies the brakes without the possibility of over-setting due to rotational momentum of the rotor since this is entirely disconnected from the brake-setting mechanism.