GB169219A - Improvements in means for controlling and actuating machines and apparatus - Google Patents

Abstract

169,219. Gauldie, K.. June 10, 1920. Gearing for stopping and starting machinery.- Comprises means for controlling a machine or apparatus in accordance with the magnitude of the pressure applied to a confined mass or aggregate of easily-deformable substance which is solid or possesses the properties of a solid in such degree that it will not leak through a small orifice, the hydrostatic or similar pressure existing in the said mass being utilized to control ther machine either directly or through a relay. As applied to means for preventing the overloading of a crane at different radii, the hoisting rope is secured to a sliding member U containing the easily deformable mass C, which may be indiarubber, so that the pressure on this mass is proportional to the load. This pressure is transmitted, by means of liquid in a flexible receptacle B, to a pressure-gauge on which the pointer can make contact with two spring-controlled contact arms P bearing against stops Q at points corresponding to loads of, say, 5 and 10 tons. These contact arms are in circuit with the solenoid of a circuit-breaker 0 and the two parts of a switch S operated in accordance with the radius at which the load is suspended. The result is that the circuit-breaker opens the main motor circuit if the load exceeds 10 tons at any radius, or if a load of over 5 tons is traversed beyond the 50 feet radius. In a modification, the pressure of a liquid is transmitted, as through the pipe A and the receptacle B to the easily-deformable mass C which acts on a spring or weight-loaded piston, so that when the liquid pressure exceeds a predetermined maximum the piston is operated against the spring or weight and releases a weight which operates a motor switch, trip valve, or other mechanism. This piston may control, directly or indirectly, the cut-off and discharging gear of an automatic machine for weighing predetermined quantities. Instead of using a radius switch for a crane the load on a single small piston may be controlled in accordance with the radius of operation so that at a large radius the piston lifts at a low pressure and at a small radius the piston lifts at a higher pressure. Specification 151,130, [Class 106 (ii), Dynamometers &c.], is referred to.