Patent GB-190406504-A (GB)
Title: Improvements in Variable Speed Gears.
Inventor: STURGESS GEORGE FREDERICK
Filed: 1904-03-17
Granted: 1905-06-15
Abstract: 6504. Sturgess, G. F. March 17. Driving - mechanism ; brakes.-Relates to various forms of toothed variable-speed epicyclic gearing applicable to cycles &c. The members are always in gear, and parts of the gear can be set eccentric to other parts to vary the speed or produce reverse motion, or may be set concentric to cause the gear to rotate as a whole. The ends 48, 48<a>, Figs. 1, 1<a>, and 2, of the driving-axle of a road vehicle, are connected by balance gear to which is secured the sun-pinion 48, gearing with planets 18 carried by axles 18<c> bearing in loose carrier-plates 11, 13. The planets 18 also gear with pinions 9, 15, 18<a>, secured to separate universally - jointed shafts 9<a>, 15<a>, 18<b> passing through the carrier-plate 13, from any of which the power may be taken. A plate 7, to which the chain, belt, or other power is applied, and a plate 10 connected to it by an Oldham coupling 8 are carried in bearings 2, 3 which are adjusted vertically simultaneously in opposite directions by screwed shafts 2<a>, 3<a>, carrying pinions gearing with a tuothed quadrant secured to the shaft 4a. The shaft 4<a> is turned by a spring handle 5, Fig. 1<a>, which may enter any of the depressions 5<b> &c. in a fixed plate. In the plates 7, 10 are formed semicircular sets of teeth 7<a>, 7<b>, 7<c>, 10<a>, 10<b>, 10<c>, one side, such as 7<e>, of each being plain. In the normal position, with the handle 5 in the depression 5<b>, the plates 7, 10 are concentric with the shafts 48, 48<a>, and the planetwheels are looked to one side of the semicircular sets of teeth, and the whole gear rotates bodily, the universally-jointed driven shafts turning on their axes at the same speed as the plate 7. If the load over-runs the driving-power, the planets 18 pass over to the plain portions of the plates 7, 10, until the drive again comes into action. When these plates are eccentric, the planets 18 gear with the teeth of each in turn, and, as they are connected by the pinion 48, turn the pinions 9, 15. 18<a> backwards on their axes, thus reducing the velocity of the driven shafts 9<a>, 15<a>, 18<b>. Six positions of eccentricity corresponding to the depressions 5<c> &c., Fig. 1<a>, are provided. When the handle 5 is in the depression 5<g>, the bodily rotation and the backward rotation of one of the shafts 9<a>, 15<a>, 18<b> are equal, and that shaft is at rest, a pivoted stop 5<i> being thrown over the depression 5<h> to prevent accidental reversal, which is obtained when the handle 5 is in the depression 5<h>. When it is not necessary to allow the load to over-run the driving- power, the construction shown in Fig. 3 is used. The flywheel 19, driven by the shaft 19<b>, carries a fixed plate 25 and a free plate 26 both carrying semicircular sets of teeth which may act on both sides of the planet-wheels 28, the plate 26 being yieldingly pressed against the planets by springs 27<a> secured to the plates 25, 26. Jamming is prevented by rollers 28<c>, turning freely beside the planets 28, which roll by the side of the teeth of the semicircular sets. The planets, which are carried by carrier-plates 23, 23<b>, gear with a pinion 29, carried by a pin 29<a> loose in the plate 23<b>. The universally-jointed driven shaft 22 turns eccentrically with the plate 23 and carries a pinion 22<a> gearing with one planet 28. The bearing 24 for the plate 23 is adjusted as before, and, as the parts are decentralized, the velocity of the shaft 22 gradually decreases from equality with that of the shaft 19<b> down to zero, and finally reverses. It is stated in the Provisional Specification that, iu a cycle hub, the chain-wheel is made the eccentric driving-member and the planet-wheel support is connected to the drive or brake mechanism. It is also stated that, by adjustment, a reciprocating motion may be obtained.