I have a problem designing a mechanism intended to deliver constant output torque. One end of a tension spring is located at any of seven locations around a circular arc. The other end of the spring is attached to the start of a curved cheek. As the spring is relocated to more distant points, it wraps around the cheek, thereby lengthening the spring. The spring tension thus increases, but the requirement is that the output torque about a defined point below the cheek should be a constant. I'm trying to determine the shape of the curved cheek to achieve this.
The following link explains in detail and, most importantly, includes a drawing. Explaining (and understanding) the mechanism without the drawing is near impossible and I can't see how to post a drawing directly here.
Here's the link: https://docs.google.com/viewer?a=v&p...OGM1ZWZlMzZlOQ
Can anyone define the shape of the curved cheek, please? I'll eventually need to show how the calculations are done, if you could include those, please.
Many thanks for any help.