GB516974A - An improved outboard drive for boats - Google Patents

Abstract

516,974. Outboard drives. ARMSTRONG, A. July 12, 1938, Nos. 20699 and 33453. [Class 114] An outboard drive for boats is mounted on the stern and can be swung radially in both a transverse and a longitudinal plane. The swivel plate 5 registers concentrically with the transom base plate 2 by means of a sleeve extension 50 which registers with the centre bore of the base plate sleeve 2a, and is secured rotatably thereon by means of shoe pieces 4. The propeller drive casing 6 is pivotally mounted about a pin 7 between the brackets 56 on the swivel plate 5. The vertical cylindrical casing 8 and the lower end of casing 6 contain a vertical steering sleeve 9 integral with the propeller casing 31. Steering is effected by rotating the sleeve 9 by means of worm gear 10 actuated by the steering shaft 15 through pinions 13 and 14. These latter are located on a radius when the drive casing is vertical, so that when the drive casing is swung radially, the pinion 13 will swing out of mesh with the pinion 14, thereby interrupting the steering transmission. If. the casing swings longitudinally through meeting an obstruction, the said pinion will disengage axially. Power transmission is effected by a longitudinal shaft 26 connected at its inner end to the motor, and at its outer end to the horizonal shaft 23 in the drive casing 6 by means of dog members 24 and 25. Power is transmitted from shaft 23 to the vertical shaft 17 through bevel gears 22 and 21, and thence to the propeller shaft 20 through bevel gears 18 and 19. When the drive is tilted rearwards the dogs 24 and 25 disengage. The drive casing is held in position normally by a shear pin 30 which fractures under a severe blow thus allowing the casing to swing rearwards. The shear pin is relieved of propeller thrust during astern motion by the provision of an annular segment 31a on the propeller casing 31 which engages behind a similar segment 29b at the base of the swivel plate 5 when the casing is rotated into reverse position. The drive casing is arranged, on tilting rearwards, to trip an engine ignition switch, and to reset it on returning to normal position. When swung transversely, the drive can be locked in set positions by means of a spring-pressed detent 32 at the top of the transom base plate 2, which engages with any one of the bores of four bosses 5d in the swivel plate 5. Transverse swinging can be effected by hand. or by a hand wheel 36 geared to the sleeve 5c. An extended anti-cavitation plate may be arranged adjustably on the propeller casing to be used as an additional planing surface.