| 主权项 |
1. Apparatus for controlling a downhole device in an oil, gas or water well, the apparatus comprising a body having a control slot engaging a pin, the control slot and the pin being provided on separate parts that are movable relative to one another, such that movement of the pin relative to the control slot switches the downhole device between active and inactive states,
the slot having at least one loop wherein the pin can move between different idling configurations of the pin and slot in which the device is inactive, and at least one elongated axial track spaced around the body with respect to the at least one loop, and wherein the pin can move in the at least one elongated axial track between different configurations of the pin and slot which correspond to active and inactive configurations of the downhole device, wherein each of the at least one elongated axial track is connected to one of the at least one loop via a deviate branch track, which is configured to track the pin from one of the at least one elongated axial track into one of the at least one loop, and wherein the control slot has no separate, dedicate return path for returning the pin from the deviate branch track to the elongated axial track, wherein the pin can be switched between each of the at least one elongated track and one of the at least one loop, and wherein the pin can cycle between the different configurations within each one of the at least one loops without switching from said loop to an adjacent elongated axial track. |
