GB569330A - Improvements in or relating to mechanism for operating the hood of the pilot's cabinof aircraft - Google Patents

Abstract

569,330. Fastenings. HAWKER AIRCRAFT, Ltd., HOLLYHOCK, W. S., WHALE, S. H., and KERR, J. P. Nov. 29, 1943, No. 19933. [Class 44] [Also in Group XXXIII] An aircraft cockpit hood with integral tail piece is slidably mounted on three rails, one at each side and one at the rear of the cockpit, the rails being detachably mounted in housings on the fuselage to permit of jettisoning of the hood in an emergency, means also being provided to assist the pilot in moving the hood rearwardly against aero-dynamic forces in flight. The hood 19 is provided with trolleys 20 movable along slide rails 5, 6, the bases of which are provided with lugs 8 engaging in recesses 7 in the bases of the fuselage housings to retain the rails in position. The forward ends of the slide rails are also provided with bolts 10 engaging in sockets formed in the fixed portion of the structure. Movement of the rails is normally prevented by means of locking pins 12, Fig. 10, attached to bell crank levers 28 connected by cables 47 to the hood release mechanism. This latter comprises a tube 30, Figs. 2 and 11, housing a spring 31 compressed by a bolt 33 passing through a rectangular nut 34 engaging a plug 36 at the end of the tube and a lever 37 which may be actuated by the pilot through a cable. Rotation of this lever turns the nut 34 into a position in which it can pass through the plug under the influence of the spring, which actuates the cables 47 to rotate the bell cranks 28 which first withdraw the locking pins 12 and then bear against lugs 26 on the under sides of the slide rails to disengage the lugs 8 from the recesses 7. The release spring 31 may operate under tension, or compressed fluid may be used to actuate the release mechanism. One or more panels 16 at the side of the cockpit may also be freed by operation of the hood release mechanism. The hood is moved along the slide rails by means of a rack and pinion 49, 50, Fig. 12, on each side of the cockpit actuated by chain and sprocket gearing, the pinions 50 being keyed to a torsion shaft 51, Fig. 12, carrying a spring 56, the ends of which are secured to collars 57, 58, the former being keyed to the shaft 51 and the latter freely rotatable thereon. A ratchet wheel 59 is secured to the collar 58, and is engagable by a pawl 64. When the pawl and ratchet are in engagement, forward closing movement of the hood tensions the spring 56, the energy stored in which assists the pilot in opening the hood during flight. The spring is rendered inoperative by disengagement of the pawl, enabling the hood to be moved freely when the aircraft is parked on the ground.