Patent GB-392252-A (GB)
Title: Improvements in or relating to braking of moving devices or apparatus, particularly winding, hoisting, hauling and like gear
IPC: B66D5/26
Filed: 1931-12-04
Abstract: 392,252. Fluid-pressure brakes; winding and paying-out apparatus. ECCLES, W., 15, High Lane, Chorlton-cum-Hardy, Lancashire, PERRY, J. F., The Cottage, Bolham, Tiverton, Devon, SMITH, D. M., 37, Church Street, Stretford, Manchester, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Dec. 4, 1931, No. 33719. [Class 103 (i).] A modification of brake apparatus, such as described in Specification 301,338, [Class 103 (i), Brakes &c.], comprises a fluid-pressure controlled weight or the like applied brake, a manually operated valve for applying the brake and an inertia governor for limiting the deceleration to a value selected by the valve lever. The valve is under the joint control of the hand lever and a brake lever so that a followup action is obtained. The brake 2, 21 is applied by a weight 9 through a lever 8 and is controlled by the fluid-pressure cylinder 12. The main control valve comprises a ported sleeve 35 and a valve piston 15, 16 slidable therein. The sleeve is connected to the hand lever 86 and the piston to the brake lever 8 by linkage 39, 77, 79. Chambers 23, 24, 42 in the fixed valve casing are connected respectively to a pressure liquid accumulator 21, the brake cylinder 12 and to an exhaust tank 22. The governor 34 which may be of the kind described in Specification 301,525, [Class 57, Governors &c.], or 393,598, [Group XXVI], comprising a flywheel driven by shaft 62 from the apparatus to be controlled actuates the piston 63 of a relay valve adapted to control pressure supply to and exhaust from the chamber 17 of the main valve. The sleeve 70 of the relay valve is connected by linkage 59, 54, 39 to the valve piston 15, 16. Chambers 65, 29, 64 of the relay valve are connected to the accumulator 21, the chamber 17 and exhaust tank 22. In the condition shown pressure fluid is supplied to the brake cylinder 12 through valve ports 44, 46 to hold the brake off. Assuming first that the governor control is cut out by turning the cock 27 to connect the chamber 17 to exhaust passage 32, the brake may be applied by the lever 86 lifting the sleeve 35 to connect the cylinder 12 to exhaust through ports 46, 47. The consequent downward movement of the lever 8 lifts the piston 15, 16 thus tending to close the port 46 so that the usual follow-up action is obtained. When the brake is applied, the relay valve sleeve 70 is raised by the piston 15, 16 through the linkage 54, 59 and if the cock 27 is in the position shown so that the governor is operative and the deceleration should exceed that determined by the position of the sleeve 70, the relay piston 63 will be lifted sufficiently to connect the ports 69, 70 in the sleeve and thus to connect the valve chamber 17 to the pressure source. The piston 15, 16 will thus be raised to connect the ports 44, 46 permitting pressure supply to the brake cylinder and partial release of the braking pressure. The lifting of the piston 15, 16 also lifts the valve sleeve 70 through the linkage 54, 59 so that the port 69 is re-closed. The reduction of the deceleration lowers the piston 63 so connecting the chamber 17 to exhaust and lowering the piston 15, 16 until the port 46 is closed and the sleeve 70 lowered to re-close the port 69. In the case of a lift, to allow the deceleration to be varied in accordance with the position of the cage, the lever 54 is pivoted on a lever 55 which is connected by a rod 57 to a winder depth indicator which thus modifies the position of the sleeve 70. The brake may also be applied in emergency or otherwise by the de-energization of a solenoid 88, a weight 89 then acting to raise the valve sleeve 35 to its highest position. The link 72 instead of being connected to the lever 39 may be connected directly to the rod of the piston 15, 16. To prevent the failure of the fluid-pressure from producing a sudden application of the brakes, a non-return valve 73 is provided in the pressure pipe and a similar valve 26 in a pipe connecting the brake cylinder valve chamber 24 to the pressure chamber 23 so that the pressure fluid is prevented from returning to the accumulator 21 and the cylinder 12 serves as a temporary supply for the pressure chamber 65 of the governor.