| 摘要 |
569,563. Vehicle driving and steering mechanism. BOOLE, R. May 24, 1943, No. 8248. [Classes 80 (i) and 80 (ii)] [Also in Group XXXI] Hand driving mechanism for invalid chairs and the like comprises an oscillating lever connected by a single flexible member to two oscillating members mounted by freewheels on a shaft or shafts parallel to the axis of oscillation of the lever, the fulcrum of the latter being midway between the points of attachment of the flexible member. Handles 1a, 1b, Fig. 1, are carried on a pivot 7 fixed to a chain-wheel 2 the chain of which passes round freewheels 3a, 3b on a driven shaft 4, and round a spring tensioning pulley 5. A ball-ended lever 8 connected to the handle assembly is associated with the steerable wheels of the vehicle. In a modification, the main chain-wheel 1, Fig. II, is connected by a chain 4 to wheels 2a, 2c, on parallel shafts carrying additional wheels 2b, 2d, respectively. Wheels 2b, 2c are connected by a chain 3. Wheel 2c, and one or more of the other wheels, are freewheels. In another modification the wheels 2b, 2d are directlymeshing gear-wheels. In a modification the handle 2b is fixed to a sprocket wheel 1b, Figs. IV, V, and the handle 2a to a dished disc 1a with a smooth perimeter 8b and four sprockets 7a ... 7d. A driving chain passes round these parts as shown and round sprockets 3a, 4a, the shafts of which carry sprockets 3b, 4b. Two or more of these sprockets, 3a ... 4b, are freewheels, the sprockets 3b, 4b being connected by a chain to a sprocket 5 on the driven shaft. The hubs of the sprocket wheels 1a, 1b are screwthreaded with different pitches and are connected by a spindle 10, screwed to correspond. The spindle 10 is connected to the steerable wheels of the vehicle. When the handles 2a, 2b are oscillated in unison the driven shaft is driven continuously in one direction. If the handles 2a, 2b are moved relatively to one another the spindle moves axially to cause steering of the vehicle. The four sprockets 3a ... 4b may be mounted in a gear-box and arranged to give a reverse drive. As shown in Fig. VI, all sprockets are freewheels, one pair 3a, 4a being arranged to drive in one direction and the other pair 3b, 4b in the other. Clutch plates 4, splined to the spindles have dogs 5a, 5b on opposite sides engageable with dogs 2a, 2b on the outer members of the freewheels. The plates 4 are connected together by a disc 7 connected to an operating cable so that they can be slid to lock either pair of freewheels to their spindles according to the direction of drive required. In a modified steering construction the main chain-wheel forms the central member of a differential gearing, an operating lever being attached to each of the two balance shafts which are internally threaded or splined to dperate with a spindle such as shown in Fig. V. |
