“The object of the runner is to preserve the parallelism of the cheek and bench-front. In fig. 245 A shows the runner and the way in which it is attached to the cheek B. This runner works in a case, formed by the boards C, C, which extend from front to back of the bench and enclose the runner on both sides, keeping it in position.
The screw D may also work in a case, whose sides E, E, should just touch the threads of the screw as lightly as possible.”
Notes: This is an extremely interesting and simple design for achieving parallelism in a leg-vise, by restricting the movement of the runner inside the case. The concept is similar to the Pinless Leg Vice, (designed by Richard Maguire) which uses a linear bearing. Technically, if the runner A, is constrained by the case, then the vice is not able to wrack. The longer the runner is, the more efficient this becomes.
Anyone built something similar to this?