US 5,186,481 A · Bicycle with improved front fork wheel suspension

Abstract

In accordance with a preferred embodiment, a front fork wheel suspension of a bicycle has two telescoping suspension assemblies, one on each leg of the front fork. Each of the suspension assemblies includes a pair of telescoping tubes having a hydraulic fluid and an airspace therein, as well as a spring-loaded valve which regulates the flow of hydraulic fluid between the two tubes of the telescoping assembly. To control the point at which the assemblies change from a rigid, locked condition, in which the valve plate is closed, to a shock absorbing, telescopically displaceable condition, in which the valve plate is open, an adjustor rod is provided by which the degree of precompression of the valve spring can be changed. Furthermore, in order to improve the rigidity of the fork, the cross member interconnecting the lower tubes of the suspension assemblies has a compound cross-sectional shape which goes from circular cross section at a U-bend portion into a rectangular cross section at straight, leg portions thereof.

Claims21

Dependent claims

A front fork wheel suspension for a bicycle comprising a pair of suspension assemblies, each of which comprises an upper and a lower telescoping tube, the upper tubes of the suspension assemblies being connected by a crown member carrying a steering tube, and the lower telescoping tubes being connected by a U-shaped cross member;

wherein the U-shaped cross member has a U-bend portion of a circular cross-sectional shape for resisting torsional forces acting to twist or rotate the suspension assemblies, and having straight leg portions of a rectangular cross section for resisting side loading forces acting to cause the suspension assemblies to move independently of each other.

In a pedal driven bicycle having a handlebar, a frame and a front fork with a wheel suspension of the type having a pair of telescoping suspension assemblies, each of which is disposed on a respective leg of the front fork, the improvement wherein each of the telescoping suspension assemblies has a fluid containing circuit for controlling compression of the telescoping suspension assembly, said fluid containing circuit means including a means for preventing pedal drive energy absorption by locking the suspension assemblies against compression by resisting low input forces imposed upon the fork, via the handlebar and frame of the bicycle, as a result of a pedaling action of a rider of the bicycle and for enabling compression of the suspension assemblies for absorption of impact shocks imposed upon the front fork by a wheel carried thereby by reacting under the effect of high input forces;

wherein each said suspension assembly includes an upper telescoping tube and a lower telescoping tube, said telescoping tubes being configured such that one said telescoping tube is axially, slidably engaged within the other of said telescoping tubes;
wherein said fluid circuit means comprises a fluid-holding chamber having a portion within each of said tubes, a viscous fluid being disposed within said chamber;
a pressure responsive fluid valve means disposed within said chamber for metering fluid flow from one of said tubes to the other of said tubes upon axial sliding movement of said tubes relative to one another, said valve having a normally closed position and opening under pressure forces that are greater than those created by pedaling and which correspond to those created by wheel impact shocks;
and means for adjusting the pressure forces required to open said valve as a means for compensating for different rider weights, rider abilities, and riding conditions.

1 more element

Dependencies are inferred from the claim text.

Bicycle with improved front fork wheel suspension

Life of this patent

Bicycle with improved front fork wheel suspension

Life of this patent

Abstract

Claims21