US 5,667,234 AGranted

Bicycle, a front fork and a shock absorber mechanism for the front fork of a bicycle

AssigneeFichtel & Sachs AG

InventorsWolfgang Zirk, Gerald Bischof

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Abstract

A telescoping front fork of a bicycle which has a spring system which acts between an upper cylindrical housing and a lower cylindrical housing and includes at least one suspension spring, a supplemental spring and a spring in the rebound direction, each of which is made of a compressible elastic foamed, or expanded cellular elastomer. The spring constant of the supplemental spring is lower than that of the suspension spring. This arrangement has the advantage that acceleration peaks are reduced during the transition from a situation in which the two cylindrical houses are at rest and one in which the two cylindrical houses slide in relation to one another. The breakaway force is oriented to the weaker supplemental spring in connection with the rebound direction spring and as the support force increases, the suspension spring is compressed on a delayed basis, without any measurable additional breakaway force.

Claims13

Dependent claims

A bicycle front fork structure comprising two legs and a bridge connecting said two legs;

said two legs comprising at least one tubular leg, said at least one tubular leg comprising:
an upper cylindrical housing connected to said bridge;
a lower cylindrical housing;
said upper cylindrical housing and said lower cylindrical housing being coaxially oriented with respect to one another to retract and extend one within the other;
spring means;
said spring means comprising upper spring means and lower spring means;
said lower spring means operatively connecting said upper cylindrical housing and said lower cylindrical housing;
said lower spring means being disposed to prevent said upper cylindrical housing and said lower cylindrical housing from moving apart and extending from one another excessively on rebound;
said upper spring means comprising compression spring means being disposed in said upper cylindrical housing;
an additional spring;
said additional spring being disposed between said upper spring means and said lower spring means;
an additional hollow cylindrically shaped member being disposed within at least one of said upper and said lower cylindrical housings;
said additional hollow cylindrical member being substantially closed upwardly;
said additional spring being wholly disposed within said additional hollow cylindrical member;
and
said additional hollow cylindrical member being disposed to permit transfer of a first force between said upper spring means and said upper cylindrical member.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/577,626Filed 22 Dec 1995
Priority: DE 44 46 756.724 Dec 1994
Granted: 16 Sep 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

B60G 17/02
Resilient suspensions having means for adjusting the spring or vibration-damper characteristics, for regulating the distance between a…
B60G 15/02
Resilient suspensions characterised by arrangement, location or type of combined spring and vibration damper, e.g. telescopic type: having…
B62K 25/08
With telescopic fork, e.g. including auxiliary rocking arms: for front wheel
F16F 1/445
Loaded mainly in compression: the spring material being contained in a generally closed space