Patent ID: 6119579
Filing Date: 2000-09-19
Classification: B60G,F15B

Abstract:
A fluid cylinder assembly for a work machine having a first machine component and a second machine component, comprising:a fluid cylinder including (i) a housing having a first end wall, a second end wall, and a cylindrical side wall which collectively cooperate so as to define a piston chamber, said housing being secured to said first machine component, (ii) a piston housed for translation within said piston chamber, and (iii) a rod which extends through an opening defined in said second end wall, said rod having a first rod end which is secured to said piston, and a second rod end which is secured to said second machine component;an ultrasonic transducer secured to said cylindrical side wall of said fluid cylinder for transmitting ultrasonic vibrations into said piston chamber during a first time period and receiving ultrasonic vibrations from said piston chamber during a second time period, said ultrasonic transducer being secured to said cylindrical sidewall such that a line (l.sub.1) which (i) extends through said ultrasonic transducer and said piston chamber and (ii) is positioned substantially perpendicular to said cylindrical sidewall, periodically intersects either said piston or said rod as said piston translates within said piston chamber; anda circuit which is operatively coupled to said ultrasonic transducer, wherein said circuit (i) generates a trigger signal which causes said ultrasonic transducer to transmit said ultrasonic vibrations during said first time period, and (ii) generates a piston-located signal in response to receipt of said ultrasonic vibrations from said ultrasonic transducer when said piston has a predetermined physical relationship with said ultrasonic transducer.