GB2530044A

GB2530044A - Auto variable bicycle gears

Info

Publication number: GB2530044A
Application number: GB1415958.6A
Authority: GB
Inventors: D H Hale
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-09-10
Filing date: 2014-09-10
Publication date: 2016-03-16
Anticipated expiration: 2034-09-10
Also published as: GB201415958D0; GB2530044B

Abstract

The definition of (automatic) precludes any degree of manual operation, compelling the provision of a primary force in the mechanical design. The force applying automatic state in this design, is housed in the sealed oil free compartment of the wheel hub and consists of three centrifugal weights 12 which react to road-wheel radial velocity and activate a cam mechanism 28 with corresponding lateral movement of ratio selector 2. Lateral movement of ratio selector increases or decreases the capacity of the oil drive channel varying the swept volume of oil to the impeller channel 4 resulting in an unstepped gear variation and circulating to re-enter the oil drive channel at (5, fig.4). The components of the above described automatic gearing are housed in the rear wheel hub 1 and are enclosed by screw threaded end caps which offer easy access to the internal components , however replacements or periodic maintenance is deemed unnecessary.

Description

AUTO VARIABLE BICYCLE GEARS

DESCRIPTION

Reference numbers to diagrams 1 drive hub 17 assist spring groove 2 auto ratio selector 18 wheel spoke holes 3 primary drive wheel 19 wheel hub support spindle 4 Impellar channel 20 chain wheel sprocket oil return to drive channel (24) 21 ratchets 6 oil flow holes 22 bearing race 7 oil diverter to inipdllar channel (4) 23 thrust race S diverter internal springs 24 oil drive channel 9 primary wheel tounges 25 cam plate mechanism pivot lift cams for primaiy wheel tounges 26 dowel key 11 end caps 27 pivot rollers 12 centrifugal weights 28 cam plate mechanisim 13 cain plates 29 cam plate milers 14 assist spring 30 impellor channel inserts counter spring 31 impellor channel seperators (integral) 16 oil seals

AUTO VARIABLE BICYCLE GEARS

Historical Bicycle Gears The original concept of pedal and chain operated gearing for bicycles offered a fixed ratio without variation in mobility, the pedal powered chain was connected to a sprocket cog wheel of variable diameters which can be exchanged to allow for gear ratio change. This static operation did not offer gear variation in adverse conditions, prompting alternative innovations, namely, epicyclic gearing, sprocket change mechanism, dual chain wheel etc. all with stepped gearing and every design requiring manual gear selection while cycling. Variable gears now exist in many forms and with various methods of propulsion and control, each bound by the criteria of mechanical design and often offset by the problems of weight, durability, reliability, and external method of control, therefore resulting in a design with limited objective, this objective however offers a firm step to further innovation.

Progression Gear selection is achieved without manual setting or manipulation and automatically follows mounting of bicycle and depression of foot pedals which rotate the chain wheel and conseqently the hub mounted sprocket which is fitted with a ratchet to allow forward motion without continuous pedalling. The sprocket wheel is screw threaded to a ball bearing pivot shaft which enters the hub housing and is integral to the drive disk which is slotted to retain spring loaded drive tongues which revolve with the drive disc sweeping a volume of oil channelled between drive disk, and selector disk, passing oil diverter to enter impeller channel and driving to re-enter oil drive channel resulting in an unstepped variation in gear response.

Variable progression The width of the oil drive channel (24) between primary drive disk (3) and the face of ratio selector (2) controls the gear ratio and is dependent on the lateral movement of selector (2) which is pivoted on the frame spindle (19) allowing lateral movement through to a separated sealed section housing three centrifugal weights (12) coupled to a cam mechanism (28) which in combination controls the lateral moment of selector (2).

Variation in road wheel (rotational) velocity, increases and decreases the centrifugal force of the centrifugal weights (12) with consequential lateral movement of selector cam mechanism (28) and conesponding capacity variation of oil drive channel (24), which is under the pressure of driven oil, and the three tongue springs at disk (3) and is controlled in combination with the assist spring (14) and the counter spring (15) and the cam mechanism. A ratchet (21) fitted within the selector pivot, controls reverse rotation of selector(2). When radial velocity of road wheel and drive disk (3) are equal, the ratio selector (2) will also revolve, without further oil circulation.

AUTO VARIABLE BICYCLE GEARS

The total assembly of components relevant to the description are housed within the drive hub (1) and enclosed by screw threaded end caps (11) supporting a ball bearing support shaft (19).

The drive hub (1) also secures the wheel spokes (18) radiating from the outer rim. The three tongues (9) appertaining to the drive disk are spring loaded to avert obstruction of the oil diverter (7), which is also spring loaded and with the drive tongues retract to conform to the oil channel (24) variation. Integral to selector disk(2) are two inclined radial cams (10) which serve to lift the drive tongues (9) to clear the oil diverter (7) on rotation. The impeller channel (4) which circulates and drives the hub wheel (1) is separated by eight radial compartments (31) into which eight pliable segments (30) are inserted and formed with tabs, each spaced and configured to aid propulsion.

The accompanying drawings appertain to the above description are represented by the following: 1/4 Complete hub gear side view cut ay.

2/4 Complete hub gear extended.

3/4 Auto ratio selector mechanism.

4/4 Relative assembly of / hub/ selector I drive wheel.