US 5,632,702 A · Continuously variable transmission

Abstract

A continuously variable transmission utilizes a variable eccentric assembly arranged about a central transmission axis. A plurality of input and output vanes are operably interconnected to an orbiter and are sequentially engaged by input and output ratchets that circumscribe them. Positive driving connections are provided between the ratchets and vanes by outer toothed pawls yieldably mounted at the outer ends of the respective vanes. A secondary multiplier transmission can be arranged coaxially with the vanes, which are rotatably supported about the central shaft of the transmission.

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Drawings

Claims11

Dependent claims

A continuously variable transmission, comprising:

a variable eccentric assembly arranged about a central axis;
a plurality of input vanes, the respective input vanes each having an inner end, an outer end, and an intermediate section, the input vanes being rotatably supported about the central axis at their respective inner ends for variable rotation about the central axis in relation to one another, the input vanes further being pivotally and slidably coupled to the variable eccentric assembly at their respective intermediate sections;
a rotatable input ratchet concentric with the central axis and including a directionally toothed driving ring circumferentially surrounding the input vanes, the outer ends of the respective input vanes each having a yieldable tooth selectively engaging the driving ring;
and
an input drive element operably coupled to the input ratchet to impart sequential driving engagement between the driving ring of the input ratchet and the outer ends of the input vanes.

2 more elements

A continuously variable transmission, comprising:

coaxial first and second rotatable members for independent rotation about a central axis;
an eccentric assembly having a cylindrical surface formed about an eccentric axis parallel and radially adjustable relative to the central axis;
an orbiter rotatably mounted by the cylindrical surface of the eccentric assembly for rotational movement about the eccentric axis;
axially spaced input and output ratchets coaxially positioned about the central axis, the input and output ratchets having oppositely facing circular patterns of internal teeth formed thereon and centered about the central axis;
a plurality of input vanes, the input vanes each having a first end coaxially pivoted about the central axis and a second end including at least one yieldable tooth complementary to and selectively engaging the internal teeth of the input ratchet during a portion of each complete revolution of the eccentric assembly, each input vane being operably interconnected to the orbiter at a location intermediate its first and second ends;
and
a plurality of output vanes, the output vanes each having a first end coaxially pivoted about the central axis and a second end including at least one yieldable tooth complementary to and selectively engaging the internal teeth of the output ratchet during a portion of each complete revolution of the eccentric assembly, each output vane being operably interconnected to the orbiter at a location intermediate its first and second ends.

4 more elements

Dependencies are inferred from the claim text.

Description3,951 words

Summary295 words

#This disclosure relates to a continuously variable transmission. The described transmission is specifically designed for use in bicycles.

#Changeable speed transmissions for bicycles have been proposed and used for many years. These have included various rear wheel hub transmissions, which typically achieved two or three specified speed reductions, as well as derailleur systems, which use the driving chain as a force transmitting element between selectable rear and/or front sprockets.

#Both prior systems have readily-identifiable drawbacks. The limited space available within a rear wheel hub of a bicycle places severe limits on the amount of mechanism that can be included within it, and thereby prevents one from designing such a transmission with many speed changes. Derailleurs, while mechanically simple and externally accessible for adjustment and repair, exert side loading forces on driving chains designed for power transmission in a straight line. They also are subject to the frequent need for adjustment due to wear on both the chain and sprockets. The entire derailleur system is exposed to the elements and requires frequent cleaning and lubrication.

Brief description of the drawings7 figures

#A preferred embodiment of the invention is described below with reference to the accompanying drawings, which are briefly described as follows.

#FIG. 1 is a transverse sectional view through the central axis of a bicycle wheel hub containing a first embodiment of the transmission;

#FIG. 2 is a left hand end view;

Detailed description3,543 words

#This disclosure of the invention is submitted in furtherance of the constitutional purposes of the U.S. Patent Laws "to promote the progress of science and useful arts" (Article 1, Section 8).

#In FIGS. 1-7 the transmission is shown in an embodiment designed specifically for use within a rear wheel hub in a bicycle. It is to be understood that the same transmission, with minor modification, can be designed for usage within the bottom bracket shell of a bicycle

#The general nature of the continuously variable transmission can best be understood with respect to the presently preferred embodiment, which is detailed in FIGS. 1-7. This form of the transmission has been developed specifically for use in a rear bicycle wheel hub. However, the transmission components can be modified to adapt them to applications other than bicycles.

Facts

Application

08/498,189Filed 5 Jul 1995

Granted

27 May 1997

Term ended

5 Jul 2015

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification6 codes

F16H 29/12
Gearings for conveying rotary motion with intermittently-driving members, e.g. with freewheel action: between rotary driving and driven members
B62M 9/085
Involving eccentrically- mounted or elliptically-shaped driving or driven wheel; with expansible driving or driven wheel: involving eccentrically…
Y10T 74/151
Rotary crank or eccentric drive: adjustable
F16H
Gearing

Continuously variable transmission

Life of this patent

Continuously variable transmission

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims11

Description3,951 words

Drawings

Classification6 codes

Life of this patent

Description3,951 words