# US 2016/0355232 A1 · A cycling aid

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- Number: US 2016/0355232 A1
- Document ID: US20160355232A1
- Status: Published application
- Kind: A1
- Application number: 14/916,138
- Filed: 2015-02-10
- Published: 2016-12-08
- Earliest claimed: 2014-02-28
- Inventors: Alan John ROBINSON
- Web page: https://patentgrep.com/patent/US20160355232A1

## CPC

- B62M 3/04: automatically adjusting
- B62M 3/02: of adjustable length
- B62M: RIDER PROPULSION OF WHEELED VEHICLES OR SLEDGES; POWERED PROPULSION OF SLEDGES OR {SINGLE-TRACK} CYCLES; TRANSMISSIONS SPECIALLY ADAPTED FOR SUCH VEHICLES (arrangements or mounting of transmissions in vehicles in general B60K; transmission elements per se F16)

## Abstract

A crank arm for a bicycle chainset is provided. The arm comprises means for varying crank length during rotation, whereby to gain mechanical advantage.

## Claims

### Claim 1

A crank arm for a bicycle chainset, the arm having a varying crank length during rotation whereby to gain mechanical advantage, wherein the arm comprises two or more sections movable relative to each other and means for attracting and/or repelling the section to/from each other to cause the variation in length.

### Claim 2 (depends on 1)

The crank arm as claimed in claim 1, in which said crank length extends after the rotation passes top dead centre and retracts prior to bottom dead centre.

### Claim 3

(canceled)

### Claim 4 (depends on 1)

The arm as claimed in claim 1, in which the sections are slidably movable with respect to each other.

### Claim 5

(canceled)

### Claim 6 (depends on 1)

The arm as claimed in claim 1, in which the attraction/repulsion is caused by magnetic forces.

### Claim 7 (depends on 1)

The arm as claimed in claim 1, in which electromagnets are provided for causing attraction/repulsion.

### Claim at position 8

8-14. (canceled)

### Claim 15 (depends on 1)

The arm as claimed in claim 1, in which electronic actions are activated wirelessley.

### Claim 16 (depends on 15)

The arm as claimed in claim 15, in which electronic actions are activated by Wi-Fi.

### Claim 17

(canceled)

### Claim 18 (depends on 1)

The arm as claimed in claim 1, in which the amount the arm is extendible by is variable.

### Claim 19

A bicycle foot pedal mechanism comprising two cranks, each crank carrying a pedal, each of the cranks comprising two or more sections movable relative to each other, and the cranks being automatically extendible and retractable dependent upon rotation extent to cause variation in length during rotation whereby to gain a mechanical advantage.

### Claim 20

A method of gaining mechanical advantage for a bicycle foot pedal mechanism comprising: i) providing a chainset having two crank arms, each crank arm carrying a pedal and each arm being extendible and retractable so as to have a variable crank length; ii) monitoring the rotational extent of the pedals; iii) initiating extension of each arm when its respective pedal is near top dead centre; and iv) initiating retraction of each arm before said each arm reaches bottom dead centre so that said each arm does not hit the ground.

### Claim 21 (depends on 20)

The method as claimed in claim 20, in which step iii) is initiated when the pedal is just passed top dead centre; and step iv) is initiated when the pedal has travelled approximately 90 degrees.