MEDICAL DEVICES HAVING COMPACT END EFFECTOR DRIVE MECHANISMS WITH HIGH GRIP FORCE

An end effector drive mechanism has first and second pulleys and first and second jaws configured as a torque-amplifying tool assemblies. Each pulley jaw pair is configured as kinematic assembly having a compact footprint that can amplify outputs to increase the grip force applied by the jaws. The end effector drive mechanism is within a pulley envelope defined by the first and second pulleys. In certain configurations, the tool assemblies are configured to produce a grip force independent from a push-pull force that is exerted on (or by) the jaws. In certain configurations, the tool assemblies are configured to prevent undesirable reverse rotations and limit the range of travel of the jaws (or pulleys).