GB226625A - Improvements in or relating to brake mechanisms for winding engines or the like - Google Patents

Abstract

226,625. General Electric Co., Ltd., and Woollatt, G. S. Sept. 29, 1923. Regulating and control-transmitting gear for winding and paying-out apparatus.-Cornprises a brake mechanism for winding engines in which the emergency brake mechanism always comes into action slowly so long as the cage is more than a predetermined distance from the end of the run, no matter whether the braking is initiated by the operation of the emergency brake lever, by the overwinding mechanism, or by the failure of electric current or air supply, but which allows a rapid application of the brakes near the end of the run and in the circumstances applies a supplementary braking force in addition to the usual brake weights. Fig. 1 shows a brake cylinder 1 and a cataract cylinder 2, the brakes being applied by weights 6 and normally held off by pressure fluid acting on the under side of the piston 4. The normal or slow application of the brakes is initiated by moving the rods 28 downwards through the medium of the brake lever 24 which closes the fluid-pressure supply-valve 25 and opens an exhaust valve 31 communicating with the under side of the piston. The rod 28 is moved downwards also by the failure of the electric current allowing a solenoid core 39 to drop or by the failure of the compressed air supply allowing the weighted lever 41 to fall. The falling of the lever 41 also operates a switch 38 to cut off the current. When the emergency brake lever 45 is operated it closes an air valve 49 and opens the cylinder 44 to exhaust, thereby allowing the weighted arm 42 to apply the brake and cut off the current as before. This movement also actuates the 3-armed lever 52. This normally has no effect, but when the cage is less than a predetermined distance from the end of its run, a lever 55 registers with a recess on a cam 60 geared to the drum and allows the emergency brake lever 45 to be pulled over to its full extent, thus moving lever 52 sufficiently to cause interaction with the lever 35, thereby moving the lever 28 downwards to an additional extent, to re-open the valve 25 and close the exhaust valve 31. At the same time, the additional movement of the lever 45 operates through the links 63, 70 to release a weighted arm which is linked to the rod 17. The movement of the rod 17 reverses the distributing valve to admit steam above the piston 4 to supply the additional braking pressure. The overwinding mechanism acts on the weighted arm through the rod 69. In some cases only one brake lever is used, and in this instance the cam mechanism may be arranged to allow the brake lever to have an additional length of stroke when near the end of the run, in order to get the quickaction and supplementary braking effect. Specification 15139/07 is referred to.