Piston pin unload for oil film renewal

A reciprocating engine piston and connecting rod assembly with added means to renew the oil film atop the piston pin once per revolution of the crankshaft;

• said means to renew located substantially between the small end of said connecting rod and the bottom means of the piston crown means;
• said means to renew including:
• (1) plunger means connected to or integral with said small end and rocking back and forth substantially the same as the normal oscillation of said small end;
• said plunger means including an arcuate plunger;
• and
• (2) a saddle containing an arcuate plunger bore and substantially immobile in a direction perpendicular to the oscillation axis of said small end;
• said saddle straddling a portion of said plunger means, with narrow clearances in order to establish and maintain close alignment of said plunger in said plunger bore;
• said piston pin partly disposed through said small end and partly contained in piston pin bosses;
• said piston pin bosses fixed with respect to said bottom means;
• said saddle having foot means resting on said small end oscillating underneath;
• during said crankshaft's rotation, said rocking of said plunger means powering the strokes of said plunger;
• oil constituting working fluid for said plunger;
• said oil flowing toward said plunger bore under control of upstream check valve means;
• said plunger stroking arcuately back and forth within said plunger bore;
• said plunger on the outstroke allowing intake of said oil into said plunger bore while said check valve means are held open by the upward inertial force on said piston during the top half of rotation of said crankshaft;
• said plunger on the in-stroke pumping said oil to higher pressure while said check valve means are held closed by the downward inertial force on said piston during the bottom half of rotation of said crankshaft;
• said oil at said higher pressure delivered through opening means to topside means of said saddle;
• said topside means located adjacent said bottom means of said piston crown means;
• and said oil under said higher pressure pushing up on said bottom means, lifting said piston crown means, and lifting said piston pin bosses slightly off said piston pin;
• thereby creating a small gap above said piston pin for renewal oil to enter.