Method for inserting rods into coiled tubes

Abstract

Abstract A flexible rod is attached to a spherical piston and inserted into a coiled hollow conduit through a sealed junction at one end of the conduit. The outside diameter of the rod is less than the inside diameter of the conduit and a slight clearance exists between the piston and the conduit. Pressurized fluid is introduced into the conduit at the sealed junction behind the piston. The fluid presses against the piston, thereby exerting force on the rod and the rod is simultaneously pushed from outside the junction. The fluid also acts as a lubricant between the rod and the conduit and the piston and the conduit. Because the fluid is flowing through the conduit it provides dynamic lubrication of the rod. In this manner the rod can be inserted many angular turns past the total angular distance normally computed using the equation for the ''''capstan effect'''' for the case of simply pushing a rod into a coiled hollow conduit. It is thus practical, from a manufacturing standpoint, to insert long lengths of rods into coiled tubular members.

Inventors

• 👤 A Bindari

Bibliographic Details