An engine pushrod which includes a plastic shaft in the form of a rod or tube, and a metal cap on at least one of the ends of the plastic shaft. The plastic shaft may be a molded plastic rod made from an engineered resin material, and may take one of several different shapes, such as a round or “T-shaped” cross-sectional profile. There may be a metal cap on both ends of the plastic shaft, and each of the metal caps may be shaped with a stamping process and hardened. The caps may be crimped onto the ends of the plastic shaft or they may be insert molded. Preferably, either method provides a part with excellent TIR and surface finish, and which meets torque requirements. Preferably, the assembly is lightweight and meets all requirements and the resin material is high temperature resistant and oil resistant.
1. An engine pushrod comprising a plastic shaft in the form of at least one of a tube and rod, said plastic shaft including at least one end having a shape, and an end cap on said at least one end of the plastic shaft of said engine pushrod, said end cap formed to the shape of said end of said plastic shaft of said engine pushrod wherein an entire inside surface of said end cap is contacted by plastic of said plastic shaft, said end cap having an end opening in which plastic is disposed as well as at least one hole in a surface of said end cap in which plastic of the plastic shaft is disposed wherein there is plastic disposed in each and every hole in said surface of said end cap, said plastic of the plastic shaft in said hole contributing to securement between the end cap and the plastic shaft of said engine pushrod, said end cap defining an end of said engine pushrod.
2. An engine pushrod as defined in claim 1 , wherein the plastic shaft comprises a plastic rod.
3. An engine pushrod as defined in claim 1 , further comprising a circumferential groove proximate the end of the plastic shaft.
4. An engine pushrod as defined in claim 1 , wherein the end cap is crimped onto the end of die plastic shaft.
5. An engine pushrod as defined in claim 1 , wherein the end cap is hardened.
6. An engine pushrod as defined in claim 1 , wherein the end cap is metal.
7. An engine pushrod as defined in claim 1 , wherein the plastic shaft includes a first end and a second end, said engine pushrod comprising a first end cap on the first end of thc plastic rod and a second end cap on the second end of the plastic rod.
8. An engine pushrod as defined in claim 7 , further comprising a circumferential groove proximate each end of the plastic shaft.
9. An engine pushrod as defined in claim 7 , wherein the end caps are crimped onto the ends of the plastic shaft.
10. An engine pushrod as defined in claim 7 , wherein the end caps are hardened.
11. An engine pushrod as defined in claim 7 , wherein the end caps are metal.