US 6,039,129 A · Locking system for a firing mechanism of a downhole tool

Abstract

Locking system (196) is provided for selectively locking an external sleeve (76) to a main body (74) of a downhole tool (14). Locking system (196) comprises a pair of opposed holes (198) formed in the main body (74). The holes (198) capture respective locking balls (200). A channel (210) extends from each hole (198) longitudinally about the outer surface of the main body (74). A spring (206) held within the main body (74) acts to push the balls (200) out of holes (198). Openings (212) are also formed in the sleeve (76) and disposed so that the balls (200) can protrude therethrough and contact the inner circumferential surface (28) of a drive sub (12) by virtue of the bias of spring (206). When the internal diameter of the drive sub (12) is relatively small, the balls (200) are pushed inwardly against the spring (206) and reside, at least partially, within holes (198). This prevents the balls from moving longitudinally about channels (210) thereby locking the sleeve (76) to the main body (74). However, when the internal diameter of the drive sub increases, the balls (200) are pushed radially outwardly by the spring (206) to the extent that they can then escape holes (198) and roll along channels (210). This allows the sleeve (76) to slide relative to the body (74).

Claims20

Dependent claims

A locking system for selectively locking a linearly slidable sleeve to a main body of a tool, said tool adapted to travel within a conduit, said locking system adapted to cooperate with an inner surface of a portion of said conduit and comprising:

first and second contiguous recesses formed in said main body, said first recess being of greater depth than said second recess;
an opening formed in or associated with said sleeve and locatable over said first or second recess;
and
a locking member adapted for capture within said first recess and to extend through said opening for abutment with said inner surface, said locking member being movable between a first position in which said locking member resides in said first recess and locks said sleeve against sliding relative to said main body, and a second position in which said locking member can escape to said second recess to allow said sleeve to slide relative to said main body, said locking member being movable from said first position to said second position in response to a variation in configuration of said inner surface of said portion of said conduit.

1 more element

Dependencies are inferred from the claim text.

Locking system for a firing mechanism of a downhole tool

Life of this patent

Locking system for a firing mechanism of a downhole tool

Life of this patent

Abstract

Claims20