Downhole under-reamer tool

A downhole tool comprising:

• a) a body having a longitudinal axis and a body through-bore, the body mounting an actuatable tool;
• b) a sleeve actuator having an actuator through-bore and being axially slidable in the body through-bore between a tool actuated position and a tool deactuated position;
• c) a mandrel having a mandrel through-bore and being selectively axially slidable in the body through-bore between a tool actuated position, an interlock position and a sleeve-lock position;
• wherein:
• d) an extension of the mandrel is a close sliding fit inside a first end of the sleeve actuator;
• e) said first end captivates a lock element;
• f) said body has an internal groove positioned so that when said sleeve actuator is in said tool deactuated position, said lock element is aligned with said groove and held in engagement therein by said extension while the mandrel is between its interlock and sleeve-lock positions;
• and
• g) said mandrel has an external recess positioned so that, when said mandrel is in said interlock position, said lock element is aligned with said recess, whereupon movement of the mandrel towards said tool actuated position releases said lock element from said groove permitting said sleeve actuator to be moved by the mandrel to said tool actuated position, said mandrel and sleeve actuator being locked together by the body holding said lock element in said recess between said interlock and tool actuated positions of the mandrel.

A downhole tool comprising:

• a) a body having a longitudinal axis and a body through-bore, the body mounting an actuatable tool;
• b) a sleeve actuator having an actuator through-bore and being axially slidable in the body through-bore between a tool actuated position and a tool deactuated position;
• c) a mandrel having a mandrel through-bore and being selectively axially slidable in the body through-bore between a tool actuated position, an interlock position and a sleeve-lock position;
• wherein:
• d) first lock means to lock the sleeve actuator with respect to the body in said tool deactuated position and while said mandrel is between said interlock and sleeve-lock positions;
• and
• e) second lock means to lock the sleeve actuator with respect to the mandrel and while said mandrel is between said interlock and tool actuated positions.

A downhole tool comprising:

• a) a body mounting an actuatable tool and having a longitudinal axis and a body through-bore, a slot communicating the outside of the body with the body through-bore;
• b) a sleeve actuator having an actuator through-bore and being axially slidable in the body through-bore between a tool actuated position and a tool deactuated position;
• c) a mandrel having a mandrel through-bore and being selectively axially slidable in the body through-bore between a tool actuated position, an interlock position and a sleeve-lock position;
• wherein:
• d) first lock means to lock the sleeve actuator with respect to the body in said tool deactuated position and while said mandrel is between said interlock and sleeve-lock positions;
• e) second lock means to lock the sleeve actuator with respect to the mandrel and while said mandrel is between said interlock and tool actuated positions;
• f) a flange on the sleeve actuator extending into said slot and having one of ribs and channels formed on its sides and inclined at an acute angle to the longitudinal axis;
• and
• g) a hollow bar slidable with a radial component in the slots, the other of channels and ribs being formed on the bar and corresponding with, and engaged in, said one of said ribs and channels of the flange.

A downhole tool comprising:

• a) a body having a longitudinal axis and a body through-bore, a slot communicating the outside of the body with the body through-bore;
• b) a sleeve actuator mandrel having a sleeve actuator mandrel through-bore and being selectively axially slidable in the body through-bore;
• c) a bar slidable with a radial component in the slot;
• d) a coupling between the sleeve actuator mandrel and the bar to slide the bar with a radial component in the slot on axial sliding of the sleeve actuator mandrel in the body through-bore;
• and
• e) seals between said sleeve actuator mandrel and body beyond both ends of said slot, and a seal around the bar in the slot, which seals define between them a chamber enclosing lubricating oil to lubricate said coupling.