Patent ID: 6988551
Filing Date: 2006-01-24
Classification: E21B

Abstract:
1. A jar having an adjustable triggering load, comprising: a housing having upper and lower housing sections and including an anvil surface; a mandrel movable relative to the housing under an applied load and having a hammer surface to impact the anvil surface; a trigger sleeve axially positioned within the housing; a collet engaging the mandrel and releasing the mandrel to cause the hammer surface to impact the anvil surface upon being moved into registration with the trigger sleeve; a spring disposed within the housing to resist longitudinal, axial movement of the collet relative to the trigger sleeve upon application of a load to the mandrel until the collet releases the mandrel; and an adjustment mechanism carried by the housing and coupled to the trigger sleeve to selectively position the trigger sleeve within the housing in establishment of a required applied load in order for the collet to be moved against the spring resistance and into registration with the trigger sleeve to thereby release the mandrel and cause the hammer surface to impact the anvil surface; the adjustment mechanism including an adjustment mandrel disposed between an end of the upper housing section and an end of the lower housing section, the adjustment mandrel being axially movable relative to the upper and lower housing sections; the adjustment mechanism further including an adjustment sleeve disposed between the housing sections and around the adjustment mandrel, the adjustment sleeve being coupled to the adjustment mandrel such that rotation of the adjustment sleeve relative to the housing sections produces axial movement of the adjustment mandrel relative to the housing sections.