Hydraulic cylinder end member arrangement for a piston position sensing system

In a hydraulic cylinder piston position sensing system employing high frequency electromagnetic waves in the hydraulic fluid filled cavity on the rod side of the cylinder, the improvement comprising:

• an end member that surrounds and supports a piston rod, said end member being removably fastened to the end of said cylinder, said end member at said end of said cylinder having a portion that defines a space surrounding said rod that serves as an extension of said cavity, said end member having first and second signal coupler ports each extending through said end and into said extension of said cavity and positioned with about ninety degree separation on the periphery of said cylinder, said end member having a hydraulic fluid ingress and egress port extending through said end and into said extension of said cavity, and, said end member providing damage protected support for electronic packaging in the vicinity of said ports.

A hydraulic cylinder piston position sensing system in the cavity on the rod side of the cylinder, comprising:

• input and receiving signal coupler ports extending into an extension of said cavity through a rod supporting head attached to the end of said cylinder;
• and
• electronic circuitry for providing an indication of piston position in a hermetic package having high frequency input and receiving sections between opposing sides with lower frequency circuitry in at least a part of the remainder of said package, said circuitry being positioned substantially between said ports of said rod supporting head, and having signal couplers within said ports for transmitting and receiving radio frequency signals to and from said extension of said cavity.

The process of coupling electromagnetic wave signals in a hydraulic cylinder piston position sensing system, comprising in combination the steps of:

• providing a hydraulic cylinder with means for introducing and sensing high frequency electromagnetic waves in the hydraulic fluid filled cavity on the rod side of said cylinder;
• and
• fastening an end member on the rod end of said cylinder that surrounds and supports a piston rod, said end member being removably fastened to the end of said cylinder at a first face and having a portion separated from said rod by a space surrounding said rod that defines an extension of said cavity, said end member having first and second signal coupler ports each extending into said cavity and positioned with separation on the periphery of said cylinder, said end member having a hydraulic fluid ingress and egress port extending into said extension of said cavity, and said end member providing damage protected support for electronic packaging in the vicinity of each said port.