Abstract: An on-off tool for latching a sucker rod to a plunger rod has a housing, a pawl, guide pines, and a key. One end of the housing is connected to the sucker rod, and an interior of the housing defines a key slot terminating at a seat inside the interior. The pawl is disposed in the interior of the housing and is biased longitudinally preferably by disc springs. Bearings in the form of elongate pins are engaged between the pawl and the housing and dispose longitudinally in slots to guiding longitudinal movement of the pawl in the interior and preventing rotation of the pawl. The key has a head at its distal end that is passable through the key slot, interlockable with the pawl, and seatable on the seat. The key's head preferably defines a waist thereabout to provide the head with greater load bearing surface to engage the housing's seat.

Abstract: An on-off tool for latching a sucker rod to a plunger rod has a housing, a pawl, guide pines, and a key. One end of the housing is connected to the sucker rod, and an interior of the housing defines a key slot terminating at a seat inside the interior. The pawl is disposed in the interior of the housing and is biased longitudinally preferably by disc springs. Bearings in the form of elongate pins are engaged between the pawl and the housing and dispose longitudinally in slots to guiding longitudinal movement of the pawl in the interior and preventing rotation of the pawl. The key has a head at its distal end that is passable through the key slot, interlockable with the pawl, and seatable on the seat. The key's head preferably defines a waist thereabout to provide the head with greater load bearing surface to engage the housing's seat.