GB489001A - Movable apparatus for lifting and manipulation of loads - Google Patents

Abstract

489,001. Derricks ; launching and landing aircraft. KERVARREC, B. Jan. 15, 1937, No. 1306. Convention date, Jan. 15, 1936. [Class 78 (iv)] [Also in Group XXXIII] A derrick intended primarily for raising seaplanes on to the deck of a ship, comprises a wheeled carriage 6 running on rails 7 on the deck 8, or other surface, and provided with jib arms 2 pivoted on a shaft 5 and supported by two or more cables 10 and 11. The cables are secured at one end to points 12, 13 at the deck level, pass over control drums 9 on shaft 5 and pulleys 15 at the head of the jib, and are attached at the other end to a pylon 16. Translational movement of the carriage is controlled by the drums 9, and owing to the upper and lower ends of the cables 10 and 11 being parallel, such movement does not result in any variation in the inclination of the jib. The raising of the seaplane or other load, is effected by a cable passing over a pulley 4 and operated by a piston in a compressed air cylinder 25. Admission of air into the upper end of this cylinder for raising the load is controlled by a manual valve 29 and an automatic valve 40 which limits the pressure attainable in the cylinder 25. The manual valve 29 is opened against spring pressure by a piston 30 operated by compressed air controlled by a manual regulator 31, 32. The automatic valve 40 comprises a cylinder with compressed air inlets 41, 42 and an outlet 43 connected with the operating cylinder 25. Communication between the inlets 41 and outlet 43 is controlled by a sleeve valve 45 operable by a piston 50 working in cylinders 51 and 54 communicating respectively with a compressed air reservoir 53 at an adjusted pressure and the outlet 43 to the operating cylinder 25. When the pressure in the latter slightly exceeds that in the reservoir 53, the sleeve 45 is displaced to cut off the supply to the operating cylinder. Excessive raising effort is thus prevented, the pressure in the reservoir 53 being adjusted to suit the load. For raising seaplanes, an auxiliary derrick 18 is provided on the carriage 6. This derrick comprises a hollow piston-rod 37 slidable in a cylinder against the action of shock-absorbing springs. The mooring rope 36 of the seaplane is drawn through rod 37 until the nose of the seaplane seats in a funnel swivel-mounted at the end of the rod.