How to calculate toggle mechanisnm forces?

[Flint]

Hi,

This is not a homework question although I'll admit it could be.

I've searched everywhere trying to work out how to calculate the spreading force of a simple toggle mechanism.

I have a two equal length arms that are hinged together. One end is fixed on a pivot pin and the other can slide along a flat plane but is resisted by a fixed stop. The hinged arms are not quite in line and aligning them would increase their overall length. If I apply a force to the hinge, perpendicular to the base plane, what force along the plane will I get?

Is there an equation I can use? I don't need to consider friction in the pins or sliding surfaces just now.

Help!

 

[Ryoko]

Need a picture. But in general, you usually solve this kind of problem by balancing the torque forces across the pivot.