Bicycle suspension

US Patènt # 6863291

Invèntors:	Miyoshi; Hiroyuki (Sakai, JP)
Assignee:	Shimano, Inc. (Osaka, JP)
Appl. No.:	373867
Filed:	February 27, 2003

ABSTRACT

A computer controlled suspension system is provided for a bicycle, which can effectively absorb shock and provide stability on rough surfaces regardless of the speed of the vehicle. The suspension system has a control unit, a front suspension, a rear suspension, a front wheel terrain sensor, and a rear controller. The rear suspension is selectively adjustable by the control unit to change stiffness of the rear suspension. When the front suspension hits a bump or a depression in the surface of the ground, a signal is sent to the rear controller so that the rear suspension can react appropriately. In one embodiment, a pedaling torque sensor is operatively coupled to the control unit to input a signal that is indicative of pedaling force, and the rear controller adjusts stiffness of the rear suspension in response to the pedaling force via the control unit. In another embodiment, one or more gear position sensors are operatively coupled to the control unit to input a signal that is indicative of gear position, and the rear controller adjusts stiffness of the rear suspension in response to the gear position force via the control unit. A locking mechanism is provided to operatively coupled to selectively lock the rear suspension in a compressed condition. The front and rear suspension preferably uses at least cylinder with a coil spring and a compressible material located between individual turns of the coil spring.

BACKGROUND OF THE INVÈNTION

1. Field of the Invention

This invèntion generally relates to suspension systems. More specifically, one aspect of the present invèntion relates to computer controlled suspension systems for a bicycle.

2. Background Information

Various forms of suspension systems have been developed for vehicles in general and bicycles in particular. Bicycles, especially mountain bikes (MTB) and all terrain bikes (ATB), have been outfitted with front and/or rear suspension assemblies and systems to absorb the shock that would have been transmitted to the rider when riding on a rough road. These suspension assemblies range from very simple to very complex.

These suspension assemblies and systems, however, have been unable to suppress adequately the bucking action that often occurs when a rider traverses a bump or dip. This bucking effect is more pronounced at higher speeds, often resulting in the rider losing control and/or being thrown from the bicycle. The reason for this problem is that there has not been an efficient way to vary the rigidity of the suspension system while the bicycle is in motion.

Examples of some prior art bicycles utilizing rear suspension assemblies are disclosed in the following U.S. Pat. No. 5,445,401 to Bradbury; U.S. Pat. No. 5,470,090 to Stewart et al.; U.S. Pat. No. 5,509,677 to Bradbury; U.S. Pat. No. 5,586,780 to Klein et al.; U.S. Pat. No. 5,597,169 to Bradbury; U.S. Pat. No. 5,921,572 to Bard et al.; U.S. Pat. No. 5,924,714 to Farris et al.; U.S. Pat. No. 6,050,583 to Bohn; and U.S. Pat. No. 6,095,541 to Turner et al.

Vehicle suspension assemblies and systems often react to the weight of the operator by being compressed. In other words, the center of gravity is lowered when the operator mounts or enters the vehicle. Similarly, the center of gravity is raised when operator dismounts or exits the vehicle. Such variations in height can make mounting and dismounting or entering and exiting difficult.

In view of the above, there exists a need for bicycle suspension systems which overcome the above mentioned problems in the prior art. This invèntion addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.