Applied Power Inc.

Technical Manufacturing Corporation

Andrew M Beard

Andreas Hubertus Von Flotow

Dale W Schubert

Steven Frank Shedd

Marion Richard Earles, Jr

A seat of a vehicle is connected to the vehicle body by a support linkage that enables movement of the seat. A hydraulic actuator is connected between the seat and the vehicle body to produce motion which counteracts the influence of the vehicle body movement on the seat. An air bag, coupled between the seat and vehicle body, has a variable spring preload to compensate for differing masses placed on the seat. A motion sensor detects movement of the seat and a displacement sensor detects seat displacement. A force sensor detects a force exerted on the actuator by an operator sitting in the seat. A controller responds to the motion and displacement sensors by operating the actuator to nullify effects of the movement of the vehicle body from acting on the seat, and responds to the force sensor by varying the spring preload of the air bag to maintain the force exerted on the actuator to within a defined range.

Active vehicle seat suspension system

An active vibration isolation system (10) includes a plurality of stiff actuators, such as piezoelectric motors (12a-c; 284, 350) which support a small mass (18) inside of a case (300). A passive isolator (20) is interposed between the small mass (18) and the payload mass (M.sub.p). In the instance where the stiff actuators are piezoelectric motors, the sidewalls of the case (300) are used to provide compressive force along the variable length of each of the horizontal piezoelectric motor elements (284, 350) to prevent damage to same. Compensation circuitry (24) is connected between velocity sensors (17) and the stiff actuators to control the variable length thereof in this move-out-of-the-way system (10) and to compensate for resonating modes. Optionally, a payload mass velocity sensor (26) and associated circuitry may be used to provide additional control. Shear decouplers (282a-c; 352, 360) are used in conjunction with the piezoelectric motor elements (12a-c; 284, 350) to minimize the amount of shear force acting on the motor elements.

Stiff actuator active vibration isolation system

An active vehicle suspension employs a multi-point support system between a vehicle's chassis and cab. Each support point has an isolator which includes a linear hydraulic actuator that is connected at its quiet end to the payload by a passive vibration isolator and is connected at its vibrating end to the chassis. Each isolator also has a support spring to off-load the majority of the weight of the cab from the hydraulic actuator. An accelerometer is mounted to sense movement at a point between the linear hydraulic actuator and the passive vibration isolator. An electrical signal produce by the accelerometer is processed to operate a hydraulic valve that controls movements of the hydraulic actuator so that transmission of vibrations from the chassis to the cab is attenuated.

Active tractor suspension system

An active vehicle suspension employs a multi-point support system between a vehicle's chassis and cab. Each support point has an isolator which includes a linear hydraulic actuator that is connected at its quiet end to the payload by a passive vibration isolator and is connected at its vibrating end to the chassis. Each isolator also has a support spring to off-load the majority of the weight of the cab from the hydraulic actuator. An accelerometer is mounted to sense movement at a point between the linear hydraulic actuator and the passive vibration isolator. An electrical signal produced by the accelerometer is processed to operate a hydraulic valve that controls movements of the hydraulic actuator so that transmission of vibrations from the chassis to the cab is attenuated.

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Winchester, MA, United States of America

Andrew M Beard