Patent GB-359307-A (GB)
Title: Method and device for the automatic starting of aeroplanes
IPC: B64F1/10
Filed: 1930-12-24
Abstract: 359,307. Apparatus for launching aircraft ; automatic controls. SOC. D'ETUDE ET DE CONSTRUCTION D'APPAREILS DE T•L•M•CANIQUE, 11 bis, Rue de la Planche, Paris. Dec. 24, 1930, No. 38942. Convention date, Jan. 18. [Class 4.] An aeroplane with automatic elevator control is enabled to start and take off automatically by constraining its initial movement as regards direction and altitude until such time as the aeroplane has attained sufficient forward speed for its automatic controls to be effective. The constraining means, Fig. 1, comprise two sets of rails, one set guiding the wheels 2 of the aeroplane and the other guiding a carriage 5 upon which the tailskid 11 of the aeroplane is secured while the machine gathers speed. The aeroplane wheels 2 are guided by an outer set of rails of L-section and the wheels of carriage 5 run between upper and lower flanges of channel - section rails, both sets of rails being united by sleepers 6. A platform is mounted on the carriage 5 by means of rollers 8 running in channels 7 and is anchored to carriage 5 by elastic cords. This platform comprises a central block 9 mounted on axles 12 of the rollers 8 by triangulated links 13, 14, the latter being adjustable to vary the height of the platform. Hooks 16 co-operate with stops 18 to hold a transverse member of the tailskid, the line of thrust on the hooks is arranged to pass through their turning axis 19. The hooks are released by pulling them downwardly by means of a cable 22 actuated by the contact of a roller-carrying lever 23 with a stop fixed on the tracks. The aeroplane is started under its own power, being released by the freeing of carriage 5 from the constraint shown in Fig. 1. The height of the platform on carriage 5 is adjusted to maintain the aeroplane at an angle of incidence slightly greater than that for level flight and the elevator is set to position b, Fig. 6. The automatic controls are governed by an airspeed actuated member which ensures the take-off of the aeroplane when it has gathered sufficient speed. These controls comprise a sector of which the axis is maintained in a fixed direction in space and which carries two spaced contact strips 44, 45 electrically connected respectively to electromagnets 46, 47 adapted to start an auxiliary motor in opposite direction to operate the elevator 52. The latter is linked to a control column 53 which is connected mechanically to a pivoted arm 54 carrying spaced brushes 48, 49 adapted to rub on the contacts 44, 45. A bell-crank lever 31 is pivotally mounted on a spindle 35 integral with a segment 33. One arm of this lever carries a plate 34 disposed in the air stream, the other a brush 36 adapted to sweep contacts 37, 38 on the segment 33 as the plate 34 is carried back by the wind pressure when this is sufficient to overcome the restraint of a spring 391. The brush 36 is connected to one pole of an electrical supply and when it contacts with the strip 37 current is supplied to the brush 49 which, since the arm 54 is in the position a, causes excitation of the electromagnet 46 and effects an upward movement of the elevator to its neutral position at which point the brush 49 leaves the strip 44. As the aeroplane continues to gain speed the brush 36 is moved further to engage the contact 38 establishing a circuit through a delay-switch 39 and the brush 48 to the electromagnet 46. The elevator is thus raised further causing the machine to take off at a climbing angle until the delay switch 39 functions to break the circuit from brush 48 and establish a circuit through brush 49 to recentralize the elevator. In a modification stated to be suitable for web-balanced aeroplanes the arm 54 carries one brush only and the sector 33 the contact 37 only, the delay switch being omitted. In this case the aeroplane is stabilized at a normal angle of incidence and is not definitely tilted into a climbing attitude. In a further modification the sector 33 again carries one contact 37 only but the arm 54 has two brushes 48, 49. The brush 48 is connected to the contact 37 and is set to stabilize the aeroplane at a large angle of incidence. After the aeroplane has taken off the circuit through contact 37 is broken by a switch and re-established directly through the brush 49 stabilizing the aeroplane in level flight.