GB226334A - Improvements relating to the safe working of hydraulic elevators - Google Patents

Abstract

226,334. Hunter, J. S. Nov. 7, 1923. Valves controlled by pilot or relay valves.-In hydraulic lifts each well door is associated with one of a series of valves, the arrangement being such that when all the doors are closed pressure water flows through the series of valves to open a cut-off valve arranged in the supply pipe of the driving mechanism. When any door is open, the flow of water is stopped and the cut-off valve is closed by a spring, weight, &c. to stop the lift. The cage 6, Fig. 1, is suspended by the rope 7 and is actuated by the ram 8 working in the cylinder 9. The control rope 19 is attached to a bell-crank lever 20 which is connected by a link 21 to the plunger of the control valve 18. A pressure pipe 22 connects the valve 18 to the regulator valve 23, and the pipe 24 connects the valve 23 and cylinder 9. Exhaust pipes 25, 26 are connected to the valves 23, 18. A pipe 31 conveys pressure water from the service pipe 16 to a cylinder 15 on the top floor. Similar cylinders 14, 13 are provided at the other floors and are connected by a pipe 33. A pipe 34 connects the lowest cylinder to the control cylinder 27 for the regulator valve, and exhaust pipes 37, 36.' 35 opening into a pipe 38 put the cylinders into communication with the main exhaust pipe 26. Within the bore of each cylinder are four tubular distance-pieces 44, Fig. 2, holding in position three annular U-leathers 45. The two middledistance-pieces are perforated, but the end ones have solid walls. A tubular plunger 46 slides axially through the U-leathers and has two series of radial apertures 51, 52 which in the position shown, i.e. with the door open, register with the perforated distance-pieces and pressure water therefore cannot pass from the pipe 31 to the pipe 32 and thence through the other cylinders to the valve 27. A rod 47 attached to the plunger 46 carries a roller 50 against which the door bears during closing. When the door is closed, the plunger has been moved sufficiently far to the left to allow fluid to pass from the pipe 31 to the pipe 32. When fluid is admitted to the valve 27, the plunger 64 is moved to the left, Fig. 4, against the resistance of the weight 28 and shifts the plunger 59 to a position which permits communication between the pipes 22, 24. If the valve 18 is now opened by moving the control rope 19, pressure fluid is admitted to the cylinder 9 and the lift is raised. If the valve 18 is set to exhaust, water flows from the cylinder 9 and escapes through the pipe 26 while the lift descends. If any door is opened, the pressure in the valve 27 is not maintained, and the plunger is moved by the weight 28 to the right, thereby stopping communication between the pipes 22, 24.