Patent GB-365615-A (GB)
Title: Improvements in or relating to flying machines
IPC: B64C23/00
Filed: 1930-09-17
Abstract: 365,615. Propelling, controlling, and stabilizing aeroplanes ; aeroplane landing gear; gyroscopic apparatus. EHMIG, V., 14 bis, Boulevard de la RÚpublique, La Garenne, Colombes, France. Sept. 17, 1930, No. 27708. Convention date, Sept. 19, 1929. [Class 4.] In an aircraft having a retractible undercarriage the undercarriage wheels when in their retracted position are set in rotation by rotary silencers through which the exhaust gases of the engine escape. The rotary silencers are provided with fans which induce the layer of air on the extrados of the wings and discharge it rearwardly on to the rudder and elevator. The undercarriage, Figs. 1 and 2, comprises cranked struts 1 pivoted at 2 to the fuselage and connected at their lower ends with split axle members hinged coaxially with the struts 1. The upper ends of struts 1 carry rollers engaging in slots 4 in the front ends of rock levers 5 having shock absorbers 6 at their rear ends. Compression struts 11 slide in slots through the rear wing spars, Fig. 5, stops 18 fixed to the spars slide in slots 17 to compress springs 16. The retracting gear comprises threaded spindles 25 on which a yoke 22 to which the shock absorber is attached may be traversed by bevel gear under pilot's control. A shaft 38, Fig. 5, geared to the spindles 25 has screw-threaded portions 7 actuating simultaneously levers 8 to displace stops 18 clear of the struts 1, these being separated one from the other in flight, and thus allow the struts to slide to the position shown in Fig. 2 as the strut 1 is folded back under the constraint of lever 5. The lower halves of the undercarriage wheels are exposed beneath the wing in the retracted position. When retracted, the tyres of the wheels make contact with pulleys 31, Fig. 5, fast to the shafts of rotary exhaust chambers 32. The exhaust chambers are located in slots 33, Fig. 4, their rotation being assisted by the air stream passing through these slots. They consist of inner and outer tubes 32a, 32c, between which are located inclined vanes 40, Fig. 7, and carry fans 35 at their inner ends, which rotate in fixed casings. The perforated inner tube 32a serves as a shaft, the gases escaping through fixed tubes 41, Fig. 5, into the region of low pressure on the wings, after being cooled by the air stream over the outer surface of the tube 32c. An exhaust valve 34, Fig. 1, is fitted in the main exhaust pipe from the engine. The fans 35 are normally arranged to draw in air from the extrados of the wings through pipes 48 and to discharge it on to the rudder and elevator as shown in Fig. 18. A system of valves, however, permits of the fans being employed to actuate vacuum servomotors 42, 42a, 42b, Figs. 5 and 12, operating the controls. The fan intake pipes are led to passages in the wing spars having upwardly directed openings Figs. 16 and 17 show passages in wood and metal spars, respectively. Operation of the pilot's controls causes movement of one or other of two rods 44, Fig. 5, according as whether aileron or elevators are applied. These rods carry striking pins which engage the cocks of valves in the fan intake pipes. The method of operation is as follows :-assuming the pilot moves the control column in such a manner as to raise the right wing, thus causing the transverse rod 44 to move to the left operating the cocks 45, 51. Cock 45 turns a three-way valve 46 which closes the fan intake from the lefthand wing and directs it to the cylinder of a vacuum servomotor 42, which in turn assists the pilot, cock 51 turns a valve 52 so as to put the openings in the left-hand wing in communication with a compressed air chamber 67 so that a jet of air is outwardly directed from the extrados of the falling wing increasing its resistance and reducing its lift whilst both fans are reducing the resistance and assisting in the lift of the rising wing, of which the corresponding valves 46a, 52a are unaffected. The elevator control is similarly effected by means of a servomotor 42b although in this case the intake pipes from the main wings are not closed. The compressed air chamber 67 is charged from a pump 66 driven from a fan shaft. The distributing cocks may be actuated automatically by a gyroscope, Fig. 19, through electromagnets 53, energy being derived from a generator 62 driven from a fan-shaft. The gyroscope is mounted for precession about two axes at right-angles, the ends of the inner and outer gimbal ring pivots being provided with insulating plates 57, Fig. 19, on which rub small balls 58, Fig. 20, fixed to brushes 59 connected by insulated wires with the windings of the electromagnets. The metallic portion of the gyro frame is connected to the negative pole of the generator so that when' precession of the gyro about either axis causes one or other brush to leave the insulated portion the circuit is closed energizing the electromagnet, operating the appropriate cock to put a servomotor into operation to actuate the required controls. An interrupter 65 enables the pilot to put the automatic control into action at will. In an application to a biplane the wheels are retracted into the lower plane and the interplane struts are adapted to serve as air conduits. In an amphibian the wheels are retracted into small lower planes serving as floats, the tyres acting as balloonets on the water. The Specification as open to inspection under Sect. 91 (3) (a) comprises also the following subject-matter which does not appear in the Specification as accepted. An undercarriage possessing the features of that illustrated in Figs. 1 and 2 but non-retractible is shown in Figs. 2 (Cancelled), 3 (Cancelled), and 5 (Cancelled). It comprises split-axle members 7, rigidly connected with the front legs 1 and pivotally mounted on an axle 2 between washers 8 and an upright 9 carrying a rudder bar 10. The legs 1 are made hollow and receive brake-actuating pistons 11 adapted to be operated by compressed air, the piston rods acting directly on brake shoe expanding cams, Fig. 3 (Cancelled), illustrates the anchorage of the rearwardly-inclined compression members 15. In a modification, the front legs 1 are vertically disposed and are articulated to the wing spars and the split-axle members 7 actuate the rockers 5. A tail wheel is fitted which is retracted by means of a spring when a cable wound on the shaft 38, Fig. 5, is unwound by rotation of this shaft during retraction of the undercarriage. The slots 33, Fig. 30 (Cancelled), serve to house radiators 34 for cooling the engine. The outlet from fans 35 may be byepassed at high altitudes to the engine induction pipes to effect super charging. According to modifications, in a light aeroplane,' Fig. 31 (Cancelled), a single fan shaft is driven by rotation of the retracted undercarriage wheels and the exhaust gases from the engine are led to the fan casing and discharged with the air drawn in from the wings on to the tail surfaces, a single distributer cock in the intake pipe being operated by lateral movement of the control column. An application to a seaplane is illustrated wherein the wheeled undercarriage is omitted and a fan is driven by a rotary silencer.