Burnishing devices adapted for use in small diameter pipes

A device adapted to be mounted on a machine tool and burnish a surface on an object with controllable force along a length of said surface, comprising:

• a body having a passageway, and having a cylindrical opening communicating with said passageway;
• an accumulator piston mounted on said body for sealed sliding movement within said passageway;
• a coarse adjustment screw threadedly mounted on said body;
• a resilient member acting between said coarse adjustment screw and said accumulator piston;
• a lever pivotally mounted on said body, said lever having a forward portion extending beyond said body and having an rearward portion aligned with said cylindrical opening;
• a chamber communicating with said accumulator piston;
• an actuator piston mounted on said body for sealed sliding movement within said cylindrical opening toward and away from said rearward portion of said lever;
• a roll rotatably mounted on said forward portion of said lever;
• wherein said chamber is completely filled with liquid;
• wherein the position of said coarse adjustment screw relative to said body may be selectively adjusted to controllably vary the fluid pressure within said chamber;
• and
• whereby said device is selectively moved toward said object to burnish said surface with controllable force along said length of said surface when said object and device are rotated relative to one another.