Patent GB-1317258-A (GB)
Title: Mechanism for the emergency opening or jettisoning of the canopies of vehicles and vehicles therewith
IPC: B64D25/08
Filed: 1969-10-13
Abstract: 1317258 Canopy opening or jettisoning mechanism J MARTIN 14 Aug 1970 [13 Oct 1969 24 Nov 1969] 50249/69 and 57435/69 Heading B7G A vehicle emergency cockpit canopy opening or jettisoning mechanism which considerably reduces the possibility of collision of the ejected canopy and a subsequently ejected seat comprises means for unlocking at least part of the canopy from a vehicle and at least one primary rocket motor adapted to be secured to the canopy and to thrust it in a direction away from its normally closed position on the vehicle. A jettisoning mechanism, Fig. 3, for a longitudinally slidable aircraft canopy comprises a first lay shaft 9 rotatable by a first piston and cylinder assembly 30 whose movement is initiated through a pressurized gas generator 33 from a second piston and cylinder assembly 35 in turn actuated in response to movement of an ejection seat firing mechanism (not shown). Shaft rotation causes unlocking of the canopy and removal through connecting links 5, 6, 11 of a limiting stop 4, and the subsequent movement of a parallel linkage assembly 15 equipped with a timed delay slotting linkage 14, which then initiates, through pressurized gas generator 24 after removal of firing pin 23, the firing of primary rocket motors 28, preferably at least two, to eject the canopy. A ballistic jack or jacks or a supplementary rocket motor or motors may be used to initiate opening of the canopy prior to initiation of the primary rocket motor. In another opening mechanism Fig. 4, a canopy 50 has a side hinge at the left emergency opening being initiated as before and in identical manner by rotation of shaft 59 which releases the canopy 50 sideways so pulling out an inner portion 72 of a telescopic strut 70 attached thereto, the extended strut being prevented from recoiling by a plunger (80), Fig. 7, (not shown). The inner portion 72 has a limited movement to allow for normal canopy operation any further movement being limited by a length limiting pin (71), removable only by rotation of the shaft 59. On reaching the emergency open position, beyond the normal open position, an initiating lever 93 coupled to the side hinge actuates an ejection seat firing mechanism through an initiating linkage 94. A safety pin 101 provided to prevent accidental initiating linkage 94 is removed by rotation of shaft 59. Another jettisoning mechanism Fig. 10 (not shown) for canopies transversely hinged at the rear, uses ballistic jacks (119), for opening the canopy prior to operation of the jettisoning rocket motors (111), the jacks being actuated from gas generators 123, 124 which first release the canopy locks. Rotation of the canopy past a predetermined position then causes triggering of a hinge operated linkage to fire the rocket motors via a further gas generator (113). A further embodiment Fig. 11 (not shown) uses supplementary rocket motors (130) to open the canopy prior to jettisoning. The rocket motors are preferably located inside the canopy but their nozzles may be located outside. The jettisoning or opening of the canopy may be used to initiate the ejection seat firing mechanism.