US Patent 9550282 Compact hydraulic torque wrench cartridge

Drive plates of a hydraulic torque wrench cartridge are thickened for extended surface contact with three pawls and a direct contact with the piston rod. The drive plates are held together and are additionally stiffened by dowel pins and shoulder screws. Snap pins are axially slide able and spring loaded connecting the piston rod with the drive plates in an easily disengage able fashion. Three pawls are arrayed in a pitch adjusted with respect to the ratchet teeth pitch in correspondence with an elastic deformation of the drive plates for a balanced force transfer across them. The pawl-tooth interfaces are also in an outward opening angle preventing them from snapping free under load.