By-pass tool

Claim 1

A tool for connection as a part of a pipe string which is adapted to be disposed within a well bore, comprising a first tubular member, a second tubular member arranged concentrically within the first member to provide an annular space therebetween, said tubular members being longitudinally reciprocable with respect to one another between extended and retracted positions, first means carried by the second member for sealably engaging the first member, second means carried by the first member for sealably engaging the second member to define a first annular chamber between the first and second sealing means, a first port in the second member connecting the interior of the second member with the first chamber, third means for sealably engaging between the first and second members to define a second annular chamber between the first and third sealing means when said pipe string is lowered to move said tubular members to retracted position, and a second port in the first member connecting the second chamber with the exterior of the tool, said second member having an opening therein which connects the interior of said second member with said second chamber when the pipe string is raised to move said members to extended position, so as to permit drilling fluid to flow through said second chamber and out said second port and thereby by-pass the portion of the pipe string below said tool.