patchbox springs

[dave gross]

For days I have been trying to complete the installation of a domed lid patchbox.  I wanted the lid to have both the catch and "kicker" spring to act on one stud at the rear of the cover with the catch activated by a button in the heel of the buttplate....pretty standard stuff. I tried my best to make the springs for my application.  My tempering is by guess and I never did get it right..the spring would inevitably break when flexed or still be so stiff that the push button required a lot of pressure to open the lid.  In my tool box I found a couple of feeler guage assortments...from my days of setting the valves on a 427 Ford engine.  The guage strips vary in thickness from a couple of thousandths up to .050. I found that the .016 and .017 ones were the right stiffness and flexibility for my application.  They can be trimmed with tin snips, bent to most any radius when cold and even drilled for screw mounting if desired.  No heat treating for one who can't seem to get that figured out and now the lid latches firmly with a click as the catch engages its step on the stud and the push button perfoms with a gentle push.  Not exactly PC but no one will see it in my lifetime.

Dave Gross
Way down east in Maine

[George F.]

Dave, I can't solve your problem, but instead offer up what I do.All my patchboxes are domed, and my kick open spring is screwed under the finial and protrudes about 1/2" into the cavity curled into a ? shape. It rides just behind the hinge where the brass is double thick, I make my own patchboxes. They work good, except for awhile but would break. I was tempering them to the wrong temperature. I was tempering them to 610 degrees, but eventually asked here what gives, and found that 710 degrees was the answer. The latch spring I make was in the shape of a U, but have since switched to a L. I would make them as if they were sear springs. A eye to put a screw through it and that little tab to act as a fulcrum. Then I would take a  1-1/12'x  1-1/12  german silver plate and cut that slot for the tab, the screw it to the cavity in the butt, reinforcing the patchbox cavity from the butt side. I know it's a lot of work, but I am satisfied with the results. I don't expect others to go through all this but I don't mind.    ...Geo.