Counter balance system and method with one or more mechanical arms
View Patent ↗A system for counterbalancing the gravitation moment on a link when the link is supported at a point. A first spring mechanism balances the link about all axes that pass through the support point. The link can be balanced throughout a large range of motion.
1. A mechanism comprising:
a movable carriage connected with a load;
a mechanical transmission including:
a first force transfer device connected to a spring;
a second force transfer device connected to the movable carriage and operatively associated with the first force transfer device;
wherein a ratio of the motion of the first force transfer device to the motion of the second force transfer device varies along a range of motion of the movable carriage;
the movable carriage includes a carriage spring and a carriage force transfer device connected between the carriage spring and the load;
a counterforce applied by the carriage spring to the load varies with a position of the movable carriage.
2. The mechanism of claim 1 , wherein:
the first force transfer device is a first cable and the second force transfer device is a second cable; and
the second cable is operatively associated with the first cable by a pulley.
3. The mechanism of claim 2 , wherein the pulley is a variable radius pulley.
4. The mechanism of claim 1 , further comprising a brake to fix the movable carriage in position.
5. A load balancing system comprising:
a first spring connected with a load so that a force is applied to the first spring by the load, the first spring having a movable anchor point;
wherein a counterforce applied by the first spring to the load varies with a position of the movable anchor point;
a mechanical transmission including:
a first force transfer device connected to a second spring;
a second force transfer device connected with the movable anchor point and operatively associated with the first force transfer device;
wherein a ratio of the motion of the first force transfer device to the motion of the second force transfer device varies along a range of motion of the movable anchor point.
6. The mechanism of claim 5 , wherein:
the first spring is connected with the load by a tension member;
the first force transfer device is a first cable and the second force transfer device is a second cable; and
the second cable is operatively associated with the first cable by a pulley.
7. The mechanism of claim 6 , wherein the pulley is a variable radius pulley.
8. The mechanism of claim 5 , further comprising a brake to fix the movable anchor point in position.