Steering damper in and for vehicles

This invention relates to vehicles and it has particular relationship to bicycles. It is to be understood that, to the extent that the principles of this invention are adapted to other vehicles than bicycles, for example, motorcycles, or even automobiles or trailer couplings, such adaptation is to be regarded as within the scope of equivalents of this invention.



Application Ser. No. 08/392,516 is typical of the prior art. Among the modifications which this invention discloses is a vehicle having integrated therein a steering damper which operates to damp the movement or rotation of the chain including the handlebars, steering stem, steer-tube, and steerable wheel when the handlebars are displaced from center and to suppress the damping when the handlebars return to center. The steering damper has a container or housing containing a damping fluid within which there are a dam and a plurality, usually two, of vanes. The housing is closed by a cap and a base. The dam is connected to, or integral with, the housing. A shaft passes axially through the housing. The vanes are connected to the shaft. The steering damper is mounted in the steer-tube with the housing and dam connected to the steer-stem rotatable with the steer-stem and steer-tube as the stem and tube are rotated by rotation of the handlebars.



The vanes and dam divide the housing into three compartments: a compartment of variable volume between the dam and one vane, a compartment of constant volume between the one vane and the other vane and a compartment of variable volume between the other vane and the dam. The vanes have one-way valves.



When the handlebars are displaced from center, the housing and base are moved so that the compartment between one vane and the dam is reduced in volume. The valve in the vane is in the closed setting and pressure is impressed on the fluid in the compartment and the fluid is conducted through a small opening in the dam or shaft which does not materially reduce the pressure and the displacement of the handlebars and the chain connected to it is damped. On the return of the handlebars to center, the fluid flows into the constant volume compartment between the vanes via recesses, typically in the cap and/or base of the housing to accommodate the flow of fluid. The pressure on the fluid is reduced and the damping is suppressed.



The apparatus disclosed in application '516 has performed highly satisfactorily. However, the two vanes and the recesses impose a substantial cost of manufacture and complicate the operation of the steering damper.



It is accordingly an object of this invention to overcome the above-described deficiencies of the prior art and to provide a steering damper adapted to be integrated in a vehicle which steering damper shall include only one vane and shall not require the recesses and shall avail effective control of the vehicle.



In accordance with this invention, there is provided a steering damper having a single vane. The vane and the dam define two compartments, one between the dam and the vane on one side and the other between the vane and the dam on the opposite side. The vane has one-way valves. Typically, each valve includes an opening in the vane which is covered by a resilient plate which normally holds it closed by the spring action of the plate. In operation, each valve is held closed by the pressure of the fluid in its corresponding compartment and opened by the pressure within the vane and relaxation of the pressure in corresponding compartment as the pressure of the fluid is affected by the position or rotation of the handlebars.



During the first phase of operation while the handlebars are displaced from center, the first valve in the vane is held closed by the fluid pressure as the dam approaches the vane in the first compartment and the fluid flows through the first opening in the shaft into the second compartment. The handlebars are damped as they move away from center. The fluid in the second compartment is supplemented from a reservoir in the steering damper. This purpose is served by an axial opening in the end of the shaft which is in communication with the second opening. Fluid circulates from the reservoir through the axial opening in the shaft's end which is connected to the shaft's transverse second opening. For return from the second transverse opening, there are two paths: one through the vane and the other directly through the end of the transverse opening remote from the vane valve. The second path offers lower resistance than the first path. The second compartment receives the needed fluid while it is expanded. In the absence of this feature, the second compartment would contain a partial vacuum causing the handlebars to spring back. By the connection of the reservoir through the bore in the end of the shaft with the second opening in the shaft, the shaft and the one-way valves in the vane are able to provide the two functions of feeding the expanding compartment with the needed fluid from the reservoir as the handlebars turn away from center and providing the suppression of damping the handlebars return to center.