Medical devices having compact end effector drive mechanisms with high grip force

An apparatus, comprising:

• a clevis;
• a central pin coupled to the clevis;
• a first tool assembly coupled to the clevis via the central pin,
• the first tool assembly comprising a first pulley and a first jaw,
• the first pulley comprising a first input connector and a first output connector,
• the first output connector extending laterally outward from the first pulley,
• the first input connector coupled to a first tension member,
• a first central opening defined by the first pulley,
• the central pin extending through the first central opening,
• the first pulley rotating about the central pin when a first input torque is exerted by the first tension member,
• the first jaw comprising a first pulley connector coupled to the first output connector, and
• the first jaw rotating when a portion of the first input torque is transferred to the first jaw via an interface between the first pulley connector and the first output connector;
• a second tool assembly coupled to the clevis via the central pin,
• the second tool assembly comprising a second pulley and a second jaw,
• the second pulley comprising a second input connector and a second output connector,
• the second output connector extending laterally outward from the second pulley in a direction opposite the first output connector,
• the second input connector coupled to a second tension member,
• a second central opening defined by the second pulley, the central pin extending through the second central opening,
• the second pulley rotating about the central pin when a second input torque is exerted by the second tension member,
• the second jaw comprising a second pulley connector coupled to the second output connector, and
• the second jaw rotating when a portion of the second input torque is transferred to the second jaw via an interface between the second pulley connector and the second output connector;
• the first pulley and the second pulley being between the first jaw and the second jaw;
• and
• a single jaw pivot pin coupling the first jaw to the second jaw, the jaw pivot pin having a first end portion coupled to the first jaw and a second end portion coupled to the second jaw, the jaw pivot pin defining a jaw pivot axis,
• the first jaw and the second jaw being configured to rotate relative to each other about the jaw pivot axis, the jaw pivot axis being offset from the central pin.

An apparatus, comprising:

• a clevis;
• a central pin coupled to the clevis, the central pin defining a central axis;
• a first tool assembly coupled to the clevis via the central pin,
• the first tool assembly comprising a first pulley and a first jaw,
• the first pulley comprising a first input connector and a first output connector,
• the first output connector extending laterally outward from the first pulley,
• the first input connector being radially offset from the central axis by a first input radius and coupled to a first tension member,
• a first central opening defined by the first pulley,
• the central pin extending through the first central opening, the first pulley rotating about the central axis when a first input torque is exerted by the first tension member, a first pulley envelope being defined as a cylindrical volume about the central axis having an envelope radius equal to the first input radius,
• the first jaw comprising a first pulley connector coupled to the first output connector, and
• the first jaw rotating when a portion of the first input torque is transferred to the first jaw via an interface between the first pulley connector and the first output connector;
• a second tool assembly coupled to the clevis via the central pin,
• the second tool assembly comprising a second pulley and a second jaw,
• the second pulley comprising a second input connector and a second output connector,
• the second output connector extending laterally outward from the second pulley in a direction opposite the first output connector,
• the second input connector coupled to a second tension member,
• a second central opening defined by the second pulley,
• the central pin extending through the second central opening,
• the second pulley rotating about the central axis when a second input torque is exerted by the second tension member,
• the second jaw comprising a second pulley connector coupled to the second output connector, and
• the second jaw rotating when a portion of the second input torque is transferred to the second jaw via an interface between the second pulley connector and the second output connector;
• a jaw pivot pin coupling the first jaw to the second jaw via a jaw pivot axis,
• the first jaw and the second jaw configured to rotate relative to each other about the jaw pivot axis, and
• the jaw pivot axis being offset from the central axis;
• and
• the first output connector, the first pulley connector, and the jaw pivot axis being within the first pulley envelope, wherein:
• the first tool assembly and the second tool assembly form an end effector that rotates about the central axis,
• an end effector center line is defined between the central axis and the jaw pivot axis,
• the end effector is configured to move between a plurality of open configurations and a closed configuration,
• the first output connector is radially offset from the central axis to define a first input link,
• the first input link and the end effector center line define an input link angle, and
• the input link angle increases when the end effector moves from the closed configuration towards the open configuration.