WO2021158182A1

WO2021158182A1 - Responsive bicycle stem

Info

Publication number: WO2021158182A1
Application number: PCT/SI2021/000001
Authority: WO
Inventors: Boris Sobocan
Original assignee: Boris Sobocan
Priority date: 2020-02-04
Filing date: 2021-01-20
Publication date: 2021-08-12

Abstract

The subject of the invention, the responsive bicycle stem, is designed around the understanding that the cause of the most dangerous acute cycling injuries, especially puncture wounds and cuts, which can occur when a cyclist falls onto a handlebar and severely injures the chest, abdomen, liver or spleen, can be eliminated with the appropriate construction of the stem. The design of the responsive bicycle stem allows the handlebar of a bicycle to rotate towards the road surface on which the bicycle's front wheel sits when the handlebars hit the road surface hard or when cyclists fall on handlebars and thus prevent the most severe cycling injuries. The responsive bicycle stem makes a significant, cost-effective and efficient contribution to the improvement of cycle safety. Due to the simplicity and robustness of its design, the responsive bicycle stem can be easily mounted onto the steering column of any bicycle and attached to all types of existing bicycle handlebars. When publishing a patent application, Figure 1 of the selected example of a responsive bicycle stem should be shown.

Description

RESPONSIVE BICYCLE STEM

Cycling brings a lot of pleasure and has a positive effect on the health and well-being of cyclists. However, cycling also has its negative sides, especially in respect of severe acute injuries that can occur as a result of falls.

In most falls, due to the rigid connection to the bicycle’s steering column and consequently to the front wheel, the handlebar is placed in a position where, due to its shape and pointed brake levers, it is the most common cause of severe cycling injuries. When cyclists fall onto the handlebar, puncture wounds and cuts can occur, severely damaging the chest, abdomen, liver or spleen of the cyclist.

(Source: https: //www.zurnal24.si/zdravje/aktualno/najbolj-nevarne- poskodbe-so-zaradi-krmila-kolesarji-varno-kolo-poskodbe-urgenca- 326258).

Existing bicycle stems cannot respond to changes in the direction and magnitude of torque that occur between the handlebars and the steering column, or the front wheel of the bicycle, when the handlebars hit the ground or when a cyclist falls onto the handlebars.

The consequences of cyclists falling onto the handlebars can be partly mitigated by wearing special protective equipment, especially safety jackets. This type of protective equipment represents an additional cost and burden, and can hinder and impede cyclists while cycling, and does not eliminate the cause of injuries when a cyclist falls onto a handlebar.

The subject of the invention, a responsive bicycle stem, is designed around the understanding that the cause of severe cycling injuries when a cyclist falls onto a handlebar can be eliminated by careful construction of the bicycle stem.

The design of the responsive bicycle stem ensures a reliable rigid connection between the bicycle’s handlebar and steering column, or the front wheel, when turning the handlebar while cycling.

The design of the responsive bicycle stem allows the handlebar to turn towards the road surface due to large differences between the magnitude and direction of torque on the handlebar and the steering column, which occurs when the handlebar hits the road surface or when a cyclist falls onto the handlebar. In this way, the responsive bicycle stem prevents the occurrence of the most dangerous acute injuries when cyclists fall on handlebars.

The responsive bicycle stem makes a significant, cost-effective, and efficient contribution to the improvement of cycling safety.

Due to the simplicity and robustness of its design, the responsive bicycle stem can be easily mounted onto the steering column of any bicycle and attached to all types of existing bicycle handlebars. The design of the responsive bicycle stem is explained in more detail below based on the description of the example and Figures 1 and 2. Figure 1 shows a floor plan and Figure 2 a cross-section of a selected example of a responsive bicycle stem.

A selected example of the responsive bicycle stem comprises a steering column clamp (1 ), a connecting element (2), a vertical hollow circular outer cylinder (3), a vertical circular inner cylinder (4), a bicycle handlebar clamp (5) and a safety connecting bolt.

The connecting element (2) connects the steering column clamp of the bicycle (1 ) to the outer cylinder (3).

The inner diameter of the outer cylinder (3) is equal to the diameter of the inner cylinder (4). The outer cylinder (3) has a connecting through-hole (6). The axis of the connecting hole (6) intersects the axis of the outer cylinder (3) and is parallel to its upper base surface.

The inner cylinder (4) is higher than the outer cylinder (3). A bicycle handlebar clamp (5) is rigidly mounted onto the upper base surface of the inner cylinder (4). The axis of the handlebar clamp of the bicycle (5) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface. The inner cylinder (4) has a connecting through-hole (7). The axis of the connecting hole (7) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface. The inner cylinder (4) has a safety through-hole (8). The axis of the safety hole (8) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface. The distance between the axis of the safety hole (8) and the upper base surface of the inner cylinder (4) is greater than the length of the outer cylinder (3).

The distance between the axis of the connecting hole (6) and the upper base surface of the outer cylinder (3) is equal to the distance between the axis of the connecting hole (7) and the upper base surface of the inner cylinder (4).

The connecting holes (6) and (7) have the same diameter.

The diameter of the safety bolt stem is equal to the diameter of the safety hole (8).

The length of the safety bolt stem, from the head to the through-hole for the safety split pin, is greater than the diameter of the inner cylinder (4).

The diameter of the stem of the connecting bolt is equal to the diameter of the connecting holes (6) and (7).

The length of the stem of the connecting bolt, from the head to the through-hole for the safety split pin, is greater than the outer diameter of the outer cylinder (3).

Due to the simplicity and robustness of its design, the responsive bicycle stem can be easily mounted onto the steering column of any bicycle and attached to all types of existing bicycle handlebars.

The installation of the example of a responsive bicycle stem is undertaken in five steps: A. The steering column clamp (1) of the responsive bicycle stem is mounted onto the steering column.

B. The inner cylinder (4) is positioned in the outer cylinder (3).

C. The safety bolt is inserted through the safety hole (8) of the inner cylinder (4).

D. The connecting bolt is inserted through the connecting hole (6) of the outer cylinder (3) and through the connecting hole (7) of the inner cylinder (4).

E. The bicycle handlebar is placed in the bicycle handlebar clamp (5) of the responsive bicycle stem.

Below is a description of the operation of the selected example of the responsive bicycle stem.

When turning the handlebar when riding a bicycle, differences occur between the magnitude and direction of the torque of the inner cylinder (4) and the magnitude and direction of the torque of the outer cylinder (3). Due to these differences, the connecting bolt is shear loaded at the cross sections at the transitions between the connecting hole (6) of the outer cylinder (3) and the connecting hole (7) of the inner cylinder (4).

During normal cycling, the shear loads of the connecting bolt are low. The connecting bolt is designed in such a way that these loads cannot exceed its limit shear resistance. Large differences between the magnitude and direction of the torque of the inner cylinder (4) and the torque of the outer cylinder (3) occur when the handlebar hits the road surface hard or when a cyclist falls onto the handlebar. In the event of such a fall, a large torque is generated on the inner cylinder (4) directed in the direction of impact on the handlebar, which is transmitted to the steering column of the bicycle via the connecting bolt, the outer cylinder (3), the connecting element (2) and the steering column clamp (1).

The bicycle steering column tries to turn the front wheel into the road surface on which it sits. The resistive force of the road surface causes a torque on the outer cylinder (3) directed in the opposite direction from the torque on the inner cylinder (4) and shear loads the connecting bolt at the transitions between the connecting hole (6) of the outer cylinder (3) and the connecting hole (7) of the inner cylinder (4). If the shear load of the connecting bolt, at the transitions between the outer cylinder (3) and the inner cylinder (4) exceeds its limit shear resistance, then the connecting bolt breaks.

After the connecting bolt has been broken, the handlebar is no longer rigidly connected to the front wheel, so it loses its support and can turn towards the road surface and prevent dangerous acute cycling injuries when a cyclist falls onto the handlebar.

The safety bolt prevents the inner cylinder (4) from falling out of the outer cylinder (3). The broken connecting bolt must be pushed out of the connecting hole, (6) of the outer cylinder (3) and out of the connecting hole (7) of the inner cylinder (4) and replaced with a new connecting bolt..

It is understood that it is also possible to construct other examples of the responsive bicycle stem. Example: Adequate rigidness of the connection between the outer cylinder (3) and inner cylinder (4) can be achieved by the forces generated on the contact of their surfaces.

It is understood that the responsive bicycle stem may have additional capabilities. First example: the inner cylinder (4) can have several parallel connecting holes (7) and safety holes (8) which allow for easy adjustment of the height of the bicycle’s handlebar with appropriate adjustment of the connecting and safety bolt. Another example: the inner cylinder (4) can be coated with a material that reduces the intensity of vibration transmission from the outer cylinder (3) to the handlebar.

The responsive bicycle stem can also be placed on other types of two or three-wheeled, foot-operated or motor-powered vehicles in which the handlebars are rigidly connected to the steering column or the front wheel.

Claims

CLAIMS OF THE PATENT

1. The responsive bicycle stem is typically formed by the steering column clamp of the bicycle (1), the connecting element (2), the outer hollow vertical circular cylinder (3), the inner vertical circular cylinder (4), the bicycle handlebar clamp (5), a safety bolt and a connecting bolt and it can be easily mounted on any bicycle.

2. For the responsive bicycle stem, according to claim 1, it is typical that the connecting element (2) connects the steering column clamp of the bicycle (1) to the outer cylinder (3), that the inner cylinder (4) is tightly placed in the outer cylinder (3), that the inner cylinder (4) is higher than the outer cylinder (3), that a bicycle handlebar clamp (5) is rigidly mounted onto the upper base surface of the inner cylinder (4) and that the axis of the handlebar clamp (5) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface.

3. For the responsive bicycle stem, according to claims 1 and 2, it is typical that the inner cylinder (4) has a safety through-hole (8) for the safety bolt, that the axis of the safety hole (8) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface so that the distance between the axis of the safety hole (8) and the upper base surface of the inner cylinder (4) is greater than the length of the outer cylinder (3) and that the safety bolt is made in such a way as to prevent the inner cylinder (4) from falling out of the outer cylinder (3) while riding the bicycle when the handlebars hit the road surface or when a cyclist falls onto the handlebar.

4. For the responsive bicycle stem, according to claims 1, 2 and 3, it is typical that the outer cylinder (3) has a connecting through- hole (6) for the connecting bolt, that the axis of the connecting hole (6) intersects the axis of the outer cylinder (3) and is parallel to its upper base surface, that the inner cylinder (4) has a connecting through-hole (7) for the connecting bolt so that the axis of the connecting hole (7) intersects the axis of the inner cylinder (4) and is parallel to its upper base surface so that the distance between the axis of the connecting hole (6) and the upper base surface of the outer cylinder (3) is equal to the distance between the axis of the connecting hole (7) and upper base surface of inner cylinder (4) and that the connecting bolt is designed to withstand the shear loads that occur on its cross-sections at the transitions between the outer cylinder (3) and the inner cylinder (4) during normal cycling, and breaks at shear loads that occur on its cross-sections at the transitions between the outer cylinder (3) and the inner cylinder (4) when the handlebar hits the road surface hard or when a cyclist falls onto the bicycle’s handlebars.