Patent GB-410193-A (GB)
Title: Improvements in or relating to telescopic columns, masts and the like
IPC: E04H12/18
Filed: 1932-10-05
Abstract: 410,193. Telescopic masts, columns, and the like; scaffolding. TAMINI, M., 2, Piazza Melozzo do Forli, Milan, Italy. Oct. 5, 1932, No. 26930/33. Convention date, Feb. 12, 1932. Divided on 408,591. [Class 78 (in).] A telescopic mast for hoisting, observation &c. is operated by forcing liquid into the interior by the expansion of air or gas from a reservoir. The action may be assisted by a pump for the liquid, and means may be provided to prevent any sudden drop if a vacuum is formed by leakage of the liquid after the mast has been raised beyond the height of a barometric column. As shown in Fig. 1, the mast carries a cantilever platform and is operated by air previously compressed into a reservoir H by a compressor G. For extending the mast, a control valve K is turned to admit air from the reservoir H to the oil reservoir I, and the oil is forced through non-return valves N, Q to the interior of the mast. The valve K is then closed, the valve N closes automatically, and the valve Q is closed by a pneumatic or electrical device as soon as a vacuum is formed in the upper part of the mast. For lowering, the valve K is turned to open the reservoir I to atmosphere through the outlet J, and at the same time a cam P on the valve lever L engages a lever O and opens the valve N. The valve Q is opened by hand. In a modification, Fig. 4 (not shown), the separate air reservoir is dispensed with, the compressed air being stored in the space above the liquid-in the reservoir I. In another modification, Fig. 5, the air is stored above the liquid in a reservoir Z which is connected with the mast through a control valve K and three conduits which respectively contain non-return valves X, Y and a pump U, and there is no exhaust to atmosphere. The liquid is forced into the mast through valves K, X, N Q and the housing may be accelerated by running the pump U. For lowering, the liquid is forced back into the reservoir through the valves Q, N, Y, Y, and the lowering may be accelerated by running the pump in the reverse direction. The valves N and Q are controlled in the same way as before. In another modification, Fig. 8, oil is forced from the reservoir 2 into the mast M through a conduit N by air stored above-the oil, and the hoisting may be accelerated by a pump W<1>, which forces oil through a conduit p and non-return valve q. After hoisting, a valve r between N and M is closed, the valve q closes automatically and is locked by a fork s operated by hand or automatically, as by a solenoid controlled by the movement of the valve. For lowering, the pump U<1> is run in the same direction, and the pressure in the conduit t. acts upon a piston wand opens a valve m to connect the mast with the conduit N. The valve m is held open by a spring tooth and the pump may be stopped during lowering. To raise the mast again, the fork s is released, and the pump U<1> is started so as to open the valve q and close the valve m. The Specification as open to inspection under Sect. 91 comprises also the use of a minimum quantity of oil in the reservoir so that the air enters the mast, and the use of locking pawls or an automatic winch hauling on a rope connected with the top section of the mast in order to prevent vertical oscillation of the mast when extended by the admission of air instead of liquids. This subject-matter does not appear in the Specification as accepted.