GB1383099A - Change speed gearing - Google Patents

Abstract

1383099 Change-speed gear FICHTEL & SACHS AG 7 Dec 1972 [16 Dec 1971] 56604/72 Heading F2D A pedal drive for a toy vehicle, which provides a forward one-way one-to-one drive by forward pedalling; a backward one-way one-to-one drive by back pedalling; and a one-way forward overdrive introduced by an additional control or by momentary backpedalling, comprises a planet gear having an output ring gear 7 pinned at 15 to a central output shaft, not shown; a sun 11 on a hollow shaft 1 which can be held in one direction in Figs. 1-4, or is permanently fixed, Figs. 5 and 6, not shown; and a planet-carrier 8, which, like the ring 7 can be driven by selectively controlled pawls 3a, 3b, 4, as described below, on a freely mounted input sleeve 2 on which is fast a sprocket 6 chaindriven by the pedal cranks, not shown. Oppositely acting pawls 3a, 3b, Fig. 3, socketed in the input sleeve 2, are outwardly biased by a surrounding spring 5 towards engagement with internal ratchet teeth in the ring gear 7, whilst a single set of forwardly directed pawls 4 are similarly biased towards engagement with the planet carrier 8. Release of the pawls for outward engagement with their respective ratchets occurs selectively when a recess 25 in a freely mounted plastics control ring 21 overlies the respective pawls, the control ring being turned selectively as follows, the ring being frictionally held by a surrounding ring 22 having projections 23 straddling a lug 24 on a stationary casing 20. On forward pedalling (input shaft 2 counterclockwise in Fig. 3) a lug 29 projecting axially from a part 19, attached to the input sprocket 6, strikes an internal abutment 27 in the control ring 21, thereby dragging the ring forwards until its recess 25 overlies and releases the pawls 3a and 4, the former then driving the output ring 7 forwards at one-to-one one-way, the latter idling the carrier 8 forwards. For overdrive, a spring-loaded cable-controlled wedge-ended plunger 31, Fig. 4, is manually allowed to enter into one-way engagement with teeth 16 on the sun shaft 1, thus stationing the latter, and the pawls 4 drive the carrier 8 to overdrive the output ring 7, the ring pawls 3a being then overrun. On back pedalling (shaft 2 clockwise, Fig. 3), a second lug 28 on the input-connected part 19 strikes the other end 26 of the ring abutment and turns the control ring 21 backwards until its pawl-release recess 25 overlies and releases the single pawl 3b, which then engages the output ring 7 for a backward one-way drive. In Figs. 5 and 6, not shown, the sun shaft 1 is permanently fixed and the pawl release recess 25 of the control ring 21 releases only one pawl at a time, so that initially, on forward drive, the pawl 3a is released alone; momentary back pedalling releases the second pawl 4 alone to drive the carrier 8 for overdrive; and continuous back pedalling releases the pawls 3b alone for one-to-one backward one-way drive.