Introducing the X Link
The X Link is my adaptation of the nineteenth century scissors mechanism used with a leg vise to eliminate the need for a pin in the lower guide board. I have used modern materials and have added improvements to make it function better and ease installation. The X Link is shown used with the VX 20 vise mechanism to create a quick action pinless leg vise. Here is a link to a YouTube video of the vise in action:
The X Link mechanism is designed to provide exact parallelism between the vise jaw and the vise leg. In practice however the vise jaw should be angled slightly so the top of the jaw contacts the workpiece first and clamping pressure deflects the mechanism slightly and makes the jaw parallel to the leg. Ideally this deflection should be kept to a minimum for best operation. In the video the jaw is spaced out at the lower jaw link end by only 0.040″ which is about 3/64″. This is accomplished by adding a shim to the mechanism. This small amount of deflection is easily accommodated by the VX 20 mechanism and full clamping pressure is applied in a half turn of the handle.
The X Link mechanism is housed in a mortise which is only 16″ long and 1″ wide. The jaw is 2-1/8″ thick and 5-1/2″ wide. In a future post I will disclose more details about the mechanism and some of the unique features which make it operate with minimal deflection and allow simpler installation.