GB2368826A

GB2368826A - Pavement bicycle steering limiter

Info

Publication number: GB2368826A
Application number: GB0027712A
Authority: GB
Inventors: Alan Charles Bush
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-11-14
Filing date: 2000-11-14
Publication date: 2002-05-15
Also published as: GB0027712D0

Abstract

A bicycle with a maximum saddle height of between 435mm and 635mm must be fitted with a steering limiter to prevent the steering from turning more than 75{ either side of the straight ahead position but must be free to turn through at least 60{ of the straight ahead position. A lower cone on the steering fork 11 has an integral protruding peg 12, which is constrained in its angular movement by a lower cup on the head tube with an open slot in which the peg runs. An internal knife-edge projection on the lower cone retains it against movement on the fork 11.

Description

PAVEMENT BICYCLE STEERING LIMITER This invention relates to a pavement bicycle steering limiter.

The introduction of BS EN 71-1: 1998, Safety of toys-Part 1: Mechanical and physical properties, saw children's bicycles with a maximum saddle height of 435mm or greater, excluded from this revised European Toy Standard.

Bicycles with a maximum saddle height of 635mm or more, and which are intended for use on public roads, fall within the scope of BS 6102 : Part 1 : 1981-Specification for safety requirements for bicycles.

There are however many children's bicycles on the market, for example those with a 14"wheel size that come complete with stabilisers, which comply with BS 6102: Partl : 1981. In order to make them comply with this standard they are fitted with an extra long seat post to ensure the saddle attains a maximum height of 635mm or more.

The International Standard ISO 8098: 1989, Cycles-Safety requirements for bicycles for young children-covers bicycles on which the maximum saddle height is less than 635mm but more than 435mm.

Within the text of ISO 8098: 1989, there is a section on Steering Stability-Clause 2.3. 4. This states that"the steering shall be free to turn through at least 60'but not more than 75'either side of the straight ahead position and shall exhibit no tight spots, stiffness or slackness in the bearings when correctly adjusted." For a bicycle to comply with clause 2.3. 4 of the International Standard ISO 8098 : 1989, it must be fitted with a steering limiter.

According to the present invention there is provided a steering limiter comprising of a limiter lower cone and limiter lower cup in which the angular movement of the cone within the cup is restricted by means of a peg that is an integral part of the cone which can only revolve within a cut out section of the bearing cup. In order to ensure that both the limiter lower cone and limiter lower cup do not move independently on the fork crown and within the cycle frames head-tube respectively, their fitted positions are maintained by provision of small locating knife-edges.

A precise representation of the invention will now be described by way of example with reference to the accompanying drawings in which : Figure 1 illustrates the make-up of a conventional headset that allows unrestricted angular movement of the steering.

Figure 2 illustrates the steering limiter lower cone from 3 different angles.

Figure 3 shows in perspective the steering limiter lower cone.

Figure 4 illustrates the steering limiter lower cup from 3 different angles.

Figure 5 shows in perspective the steering limiter lower cup.

Figure 6 shows in perspective the steering limiter lower cone and steering limiter lower cup located in their respective positions on the fork crown and within the head-tube.

Referring to Figure 1, a bicycle headset that gives unrestricted angular movement of the steering is made up of a lower cone 10 that is fitted to the fork crown 11. A lower cup 8 is pressed into the head tube 7 and a ball bearing race 9 runs between the lower cone 10 and lower cup 8. An upper cup 6 is pressed into the top of the head tube 7 and an adjustable cone 3 screws onto the threaded part of the fork tube 5. A ball bearing race 4 runs between the upper cup 6 and adjustable cone 3. A lock-washer 2 and a top nut 1 hold the headset assembly together.

Figures 2 and 3 illustrate the steering limiter lower cone, which replaces the standard lower cone. This component has an integral square peg 12 protruding from the rear face of the bearing surface plinth 13. A small integral knife-edge protrusion 14 is located on the inside surface of the limiter cone. When pressed onto the fork crown, this knife-edge 14 prevents any movement occurring between the lower limiter cone and the forks. The square peg 12 is positioned centrally to the rear face of the fork crown 11, Figure 6 refers.

Referring to Figures 4 and 5, the steering limiter lower cup replaces the standard lower cup. This component has an angular section of its cup face removed, 15. This cut out section acts as an open slot. The square peg protrusion 12 of the lower limiter cone, Figures 2 and 3 refer, sits within the open slot of the lower limiter cup. In order to maintain the limiter cups position within the head-tube, a small integral knife-edge 16 is situated on the external face of the cup. When the lower limiter cup is pressed into the head tube, the open slot is positioned centrally to the rear face of the head tube, Figure 6 refers.

Figure 6 illustrates the steering limiter in position between the fork crown 11 and head-tube 7. The side edges of the open slot in the lower limiter cup act as stops to the lower limiter cone peg 12 which prevent the steering from angular movement greater than 750 from the straight ahead position.

Claims

CLAIMS 1. A pavement bicycle steering limiter comprising a limiter lower cone with an integral protruding rear peg that has its angular movement restricted by an open slot in the limiter lower cup.
2. A pavement bicycle steering limiter as claimed in Claim 1 wherein the angular movement of the steering is restricted to a maximum ouf 75'either side of the straight ahead position.
3. A pavement bicycle steering limiter as claimed in Claim 1 and Claim 2 wherein the appearance of the bicycle is not changed or altered by its fitment.
4. A pavement bicycle steering limiter as claimed in Claim I and Claim 2 that does not result in sharp edges when fitted.
5. A pavement bicycle steering limiter as claimed in Claim 1 and Claim 2 that does not result in exposed edges when fitted.
6. A pavement bicycle steering limiter as claimed in Claim 1 and Claim 2 that does not produce an entrapment hazard when fitted.
7. A pavement bicycle steering limiter as claimed in Claim I and Claim 2 wherein no additional assembly or fabrication processes are needed during the manufacture of the bicycle.
8. A pavement bicycle steering limiter substantially as described herein with reference to Figures 2-6 of the accompanying drawings.