GB322861A - Improvements in or relating to apparatus for launching aircraft - Google Patents

Abstract

322,861. Forbes, W. A. D. Nov, 9, 1928. Launching ways.-A launching device for aircraft comprises a trolly propelled through rope and sheave gear from a prime mover along a track which can be increased in length by one or more extending portions, the increased travel of the trolly being obtained without having to accaelerate and retard any masses other than the aircraft, trolly and interconnecting rope and sheave gear. The apparatus comprises a frame which may be fixed, or mounted on a central pivot and rails 6 to which it can be clamped in any position to suit the direction of the wind. Two sliding extensions 3 are provided to lengthen the run of a trolly 11. These may be moved together or separately by electromotors, or by a hand winch actuating cable drums 20, or by temporarily securing the trolly to each extension in turn and utilizing the prime mover. They are secured in their extended positions by bolts 22, Fig. VII. A cylinder 8 on the main frame has a piston connected to a crosshead 24 carrying a number of sheaves. A cable 12 anchored to the frame at 15a is passed around two of the cross head sheaves 16a, 16b, and around two sheaves 17a, 17<a1> on the frame as shown in Fig. V ; the cable then passes over two sheaves 18a, 19<a> on the forward extension 3 and is connected to a balance pulley 14 or lever on the trolly which is connected to a duplicate cable passed around a similar set of sheaves. A similar pair of cables 13 passed around pulleys 19<b>, 18<b> on the rear extension and around pulleys 17b, 17<b1>, and 16b, 16<b1> on the frame and crosshead respectively act as retarding cables at the end of the run. The piston is moved by hydraulic or pneumatic means or by exploding a propellent such as cordite and is retarded at the end of its stroke by expelling fluid through a restricted passage into a reservoir 10. The pulleys 18<a>, 19<a>, 18<b>, 19<b> enable the trolly to be moved irrespective of the position of the extensions 3, and vice versa without affecting the lengths of the cables 12, 13. The trolly has two sets of wheels 23, Fig. VII, one set running in rails 2 on the main frame, and the other in rails 4 on the extensions 3.