Patent GB-133258-A (GB)
IPC: B66B1/04
Abstract: 133,258. Pearson, T., and Smith, R. S. April 10, 1919. Fluid-pressure apparatus; electric plant.-Relates to valve-actuating mechanism for hydraulically-actuated cage lifts of the kind in which the cage A is more than counterbalanced by a weight A<7>, and the pressure fluid is admitted alternately to opposite sides of a piston A<5> connected to the hoisting rope A<1>. The handing-rope C, Fig. 1, is attached to a drum C<1> which is operatively connected to a slide valve C<2>. Pipes C<3>, C<4> connect the opposite sides of the valve to the supply and exhaust pipes B<6>, B<7>, respectively, and double ports C<7> keep the controls not in use open to exhaust. The opposite ends of the hoisting cylinder A<6> are connected to by-pass valves B<2>, B<3> by pipes B<4>, B<5> which are connected by pipes C<5>, C<6> to hydraulic selector cylinders D, D<1>. The rams D<2>, D<3> of these cylinders carry counterweights D<4> and are connected to slide valves E, E<1> which communicate , with opposite sides of the valve C<2> by pipes E<2>, E<3>. Pipes G, G<1>, Fig. 3, connect the valves E, E<1> to the lower end of control cylinders G<2>, G<3>, and pipes H, H' connect them to similar cylinders H<2>, H<3>. The plungers J, J' of the cylinders G<2>, G<3> are connected to a lever J<2> which is pivoted at J<3> and connected by links J<5>, J<4> to the spindles of the main valves B, B', Fig. 2, on the pipes B<6>, B<7>. Slotted links K, K<1> near the ends of the lever J<2> carry weights K<2>, K<3> which normally rest on platforms K<4>, K<5>. A similar arrangement connects the plungers L, L' of the cylinders H<2>, H<3> to the spindles of the by-pass valves B<2>, B<3> and to weights M, M'. When the counterweight A' is sufficient to overcome the weight of the loaded cage, the pressure on the underside of the piston A<5> is sufficient to overcome the counterweight D<4> on the plunger D<3> and the valve E' is raised. If the rope C is now pulled to move the valve C<2> to the left, pressure fluid from the pipe C<3> passes through the valve C<2>, pipe E<3>, valve E<1>, and pipe H<1> to the cylinder H<3>, the plunger L<1> of which rises and rocks the lever L<2> so that the by-pass valves are actuated to permit fluid to pass from the bottom of the cylinder A' to the top, and the cage rises. If the valve C<2> is returned to normal position, the lever L<2> is returned to horizontal position by the weight M' and the cage stops. When the counterweight A<7> is not sufficient to overcome the weight of the loaded cage, the pressure is insufficient to overcome the counterweight D' and the valve E' does not move. On moving the rope C, pressure fluid is admitted by the pipe G<1> to the cylinder G<3>, and the consequent movement of the lever J<2> raises the spindle of the main valve B and lowers the spindle of the main valve B'. Pressure fluid is thus admitted to the upper side of the piston A<5> and the cage rises. The cage is lowered by moving the valve C<2> to the right and admitting pressure fluid to either of the cylinders G<2>, H<2>. In a modification, Fig. 6, the valves C<2>, E, E<1> are replaced by electric switches P, N, N<1>, and the control cylinders G<2>, G<3>, H<2>, H<3> by solenoids R<3>, R<2>, T<3>, T<2>.