| 摘要 |
A torque wrench for tightening or loosening of threaded connectors has a turnable engaging unit (1) arranged to be turned and to engage threaded connector so as to tighten or loosen the latter in response to turning of the engaging unit (1), and a power drive unit (2) for turning the engaging unit (1). The power drive unit (2) includes a fluid-operated cylinder piston unit provided with a cylinder (15) and two pistons (16, 17). The pistons (16, 17) are movable independently of one another, so that when one piston (17) with its smaller piston area is moved it applies a smaller pressure to the engaging unit (1) to provide a smaller torque, while when both the pistons (16, 17) with a greater combined piston area are moved together they apply a greater pressure to the engaging unit (1) to provide a greater torque. |
