Multiple actuator and linkage system
An actuator system comprising a shared link arranged to pivot about a first axis relative to a reference structure, a controlled element arranged to pivot about a second axis relative to the reference structure, a first member arranged to pivot about a third axis relative to the shared link and a fourth axis relative to the controlled member, a first actuator arranged to control a first variable distance between the third axis and fourth axis, a second member arranged to pivot about a fifth axis relative to the shared link and a sixth axis relative to the controlled element, a second actuator arranged to control a second variable distance between the fifth axis and the sixth axis, the system configured such that a change in the first variable distance causes rotation of the controlled element about the second axis when the second variable distance is constant and vice versa.
1. An actuator system comprising:
an element configured for rotary movement about a first axis relative to a reference structure;
a linkage system connected to said element and said reference structure;
said linkage system having a link configured for rotary movement about a second axis relative to said reference structure;
said first axis and said second axis being substantially parallel and operatively offset a substantially constant distance;
said linkage system configured and arranged such that a first angle of rotation between said element and said reference structure may be driven independently of a second angle of rotation between said link and said reference structure;
a first rotary actuator connected to said linkage system and arranged to rotationally control a first degree of freedom of said linkage system;
a second rotary actuator coupled to said linkage system and arranged to rotationally control a second degree of freedom of said linkage system, said first degree of freedom and said second degree of freedom being independent degrees of freedom;
wherein said first actuator is configured and arranged to drive rotation of said element about said first axis when said second degree of freedom is operatively locked.
2. The actuator system as set forth in claim 1 , wherein said linkage system comprises:
a first linkage connected to said element at a first element connection offset from said second axis and extending from said first element connection to a first member connection offset from said first axis;
a second linkage connected to said element at a second element connection offset from said second axis and extending from said second element connection to a second member connection offset from said first axis;
a first member connected to said first linkage and said first rotary actuator;
said first member configured and arranged for rotary movement about a third axis relative to said link;
a second member connected to said second linkage and said second rotary actuator; and
said second member configured and arranged for rotary movement about a fourth axis relative to said link.
3. The actuator system as set forth in claim 2 , wherein:
said first rotary actuator is configured and arranged to control rotation of said first member;
said second rotary actuator is configured and arranged to control rotation of said second member;
said first rotary actuator, said first member and said first linkage are configured and arranged to rotate said element about said second axis relative to said reference structure when said second rotary actuator operatively locks rotation of said second member about said fourth axis relative to said link; and
said link, said first and second members and said first and second rotary actuators configured and arranged such that said link rotates about said first axis when said second rotary actuator operatively locks rotation of said second member about said fourth axis relative to said link.
4. The actuator system as set forth in claim 2 , wherein said first, second, third, and fourth axis are substantially parallel to each other.
5. The actuator system as set forth in claim 2 , wherein said first member connection and said second member connection are positioned on opposite sides of an imaginary line through said first axis and said second axis or said first element connection and said second element connection are positioned on the same side of an imaginary line through said first axis and said second axis.
6. The actuator system as set forth in claim 2 , wherein said third axis is coincident with said fourth axis.
7. The actuator system as set forth in claim 6 , wherein said first axis is coincident with said third axis.