About once a year I usually page through all the back issues of the Blacksmith’s Journal. I almost always find a few things that look useful now which I didn’t really notice earlier. In the October 1991 issue on page 164 is Jerry Hoffman’s drawing of a work support idea submitted by S. L. Marak of Chula Vista, CA.
I never built one like it but it looks like a neat design. I decided to draw a version of it in SketchUp and post the model on the 3D Warehouse where it would be available for others to download.
The base was not shown, only the catch and release mechanism. The shaft fits through guide holes which closely fit around it. The catch is a toggle dog. Lifting the leading edge disengages the dog’s bite on the shaft. Gravity drops the dog into the locking position. The shaft hole through the dog is a bit oversized to accommodate the toggle motion. The dog is not securely attached to the frame. If the shaft is lifted out of the guides the dog can be removed and the tooth sharpened. The article states that the tooth should be hardened.
I drew the plan using 1/2” round rod for the shaft but 1/2” thread rod could be substituted and achieve, perhaps, more secure locking.
Published to 3D Warehouse 01/07/14.
|Catch position, release position, dog removal.|
|Dog dropped to catch.|
|Dog lifted to release.|