This apparatus is designed to evaluate forces within a toggle mechanism. Load is applied to the two pairs of links by a hanger suspended from their connecting pivot. One end of the links is pivoted to a base, and the other end is able to move sideways on low friction ball bearing wheels. The moving links are restrained by a horizontal spring balance, which measures the horizontal reaction directly. The angle of the toggle can be varied.
Adjustment is provided for returning the geometry of the loaded toggle to its original unloaded state before taking measurements. The supporting blocks are not supplied.
There are many ways in which the forces can be determined theoretically. The Instruction manual provided with the apparatus takes the opportunity to introduce the use of velocity diagrams to solve essentially static problems by considering virtual motion. However, other techniques can be used if desired.
