Actuator and zone valve

An actuator mechanism for a flue damper for the exhaust flue of a furnace, comprising:

• a support structure;
• a torque producing member mounted on said support structure;
• a rotatable shaft with a coupling at one end for making a connection to said flue damper;
• a torque transfer segment having one end coupled to said shaft;
• a hinge member rotatably coupled to said torque transfer segment at a location radially outward from said shaft;
• and
• a tension spring coupled at one end to said support structure and at the other to said hinge member, said tension spring working in conjunction with aid hinge member to provide a restoring torque to said shaft, said restoring torque being equal to the product of the spring force and an effective moment arm,
• wherein the spring, hinge member, and torque transfer segment are configured so that the effective moment arm varies inversely with the force of the spring to reduce variation in said restoring torque over an angular range of movement of said shaft of at least about 90 degrees.

An actuator mechanism for a heating system valve, for actuating said valve between first and second positions (e.g., opened and closed positions), comprising:

• a support structure;
• a rotatable shaft with a coupling at one end for making a connection to said valve;
• a torque transfer segment coupled to said shaft;
• a motor and gear elements mounted on said support structure, said motor and gear elements providing a driving torque for rotating said torque transfer segment and thereby rotating said shaft in a forward direction from said first to said second position;
• a spring mounted on said support structure and coupled to said torque transfer segment, so that said spring and torque transfer segment provide a restoring torque tending to rotate said shaft in a reverse direction;
• wherein said gear elements are so configured and so engage said torque transfer segment that, when said restoring torque is rotating said shaft in a reverse direction, said motor is driven in a reverse direction at least until said valve has returned to said first position, and, thereafter, said gear elements and said torque transfer segment disengage said motor from said shaft for a period of time to avoid an abrupt cessation of rotation of said motor.

An actuator mechanism for a heating system valve, comprising:

• a support structure;
• a torque producing member mounted on said support structure;
• a rotatable shaft with a coupling at one end for making a connection to said valve;
• a torque transfer segment having one end coupled to said shaft;
• a hinge member rotatably coupled to said torque transfer segment at a location radially outward from said shaft;
• and
• a tension spring coupled at one end to said support structure and at the other to said hinge member, said tension spring working in conjunction with said hinge member to provide a restoring torque to said shaft, said restoring torque being equal to the product of the spring force and an effective moment arm,
• wherein the spring, hinge member, and torque transfer segment are configured so that the effective moment arm varies inversely with the force of the spring to reduce variation in said restoring torque to less than 10% over an angular range of movement of said shaft of at least about 90 degrees.