Universal joint slip spline connection having concentric one-way valves

A universal joint slip spline connection including a pair of concentric telescoping members which relatively extend and contract and define a pumping chamber therebetween;

• one of said telescoping members comprising a tubular sleeve having an external splined portion, and a second sleeve surrounding and concentric with said tubular sleeve and secured at one end therewith and defining an annular space therewith which is open at the opposite end;
• and said other telescoping member comprises a splined sleeve which is adapted to be slidingly received in said annular space and in telescoping relationship therewith, and a ring seal carried by said second sleeve for sliding and sealing abutment with said other telescoping member;
• one of said members having a transverse interior wall thereacross, a dual valve unit including a threaded collar threadably engaged in said wall and located between said pumping chamber and the exterior of said connection, said unit including two concentrically arranged, one-way air valves located in said collar and which act to check the flow of air in opposite directions to thereby permit flow of air into the chamber when said connection is being extended and permit the flow of air out of the chamber when the connection is being compressed, said one-way valves each including a seal member mounted thereon and adapted to abut against a valve seat, and spring means for resiliently urging said valves to a closed position, said unit being located on the rotational axis of said connection, and an air filter located between said valve unit and the exterior of said connection.