| 摘要 |
1288399 Inflatable lifejackets SAAB-SCANIA AB 9 Dec 1969 [9 Dec 1968] 60000/69 Heading B7U [Also in Division F4] A lifejacket 1 is automatically inflated on immersion by a water-sensitive electronic switching device 27, 28 which fires an explosive cartridge 20 to pierce a CO 2 gas bottle 12 via a plunger 18, lever 16 and piercer 15. Plunger 18 alternatively may be actuated by handle 8. The switching device comprises electrode 35 and casing 25 forming between them an annular space 37 to which, on immersion, water is admitted through apertures 40. The device is in a circuit with a thyristor 42, a battery 26, a resistor 39 and the cartridge 20, Fig. 3 (not shown). Thyristor 42 prevents firing of the cartridge until sufficient water has entered space 37 to raise its conductance above a threshold value, above which an avalanche effect occurs to pass a current sufficient to fire the cartridge. The thyristor may be replaced by an equivalent transistor assembly. A coloured indicator 22, visible through window 23, indicates whether the device has been used. The lifejacket comprises an inflatable envelope within a cover 1 having a zip 4 with weakened zones which cause opening of the cover on inflation of the envelope, Fig. 5 (not shown). |
