Locking device for a drilling device

摘要

Latching device for a drilling device comprising a latching body mountable in an outer tube, an unlatching tube slidably mountable around the latching body, two latches attached to the latching body and pivotable between a deployed position in which the latch cooperates with the outer tube in order to latch the latching body to said outer tube and a retracted position for unlatching the latching body from the outer tube, a piston sliding around the latching body and secured to the unlatching tube, and a compression spring mechanism pressing the piston towards the latches in order to maintain the latches in their deployed position, a pulling force exerted on the unlatching tube compressing the spring mechanism to prevent the piston from pressing against the latches which position themselves in their retracted position.

主权项

1. A latching device for a drilling device comprising an outer tube provided with an internal shoulder, said latching device comprising:
an elongated latching body mounted within the outer tube comprising a lower portion and an elongated upper portion; an unlatching tube mounted within the outer tube around the latching body and configured to slide between a high operating position and a low rest position, said unlatching tube comprising at least two elongated lateral openings distributed therearound; at least two latches, each latch being pivotably mounted on the latching body and comprising an operative end, each latch configured to pivot between a deployed position, wherein the operative end of the latch projects outside the unlatching tube through one of the corresponding openings to abut under the internal shoulder of the outer tube thereby latching the latching body to the outer tube and preventing removal of the latching body, and a retracted position, wherein the latch is retracted near the latching body in order to unlatch the latching body from the outer tube; a tubular piston slidably mounted around the latching body proximal to the operative ends of the latches and secured to the unlatching tube, wherein the at least two latches are configured to accept the tubular piston between the operative end of each latch; and a compression spring mechanism mounted on the upper portion of the latching body and configured to press the piston towards the at least two latches thereby maintaining the latches in the deployed position in order to allow a drilling operation, wherein a pulling force exerted on the unlatching tube secured to the piston compresses the spring mechanism so as to prevent the piston from pushing against the at least two latches thereby allowing the at least two latches to move to the retracted position in order to allow an element to be hoisted up from the drilling device.