Stapler Works Again

My wife has used this Sears Craftsman 9-4860 stapler infrequently for her projects over several decades. Yesterday it would no longer work, but the trigger portion of the handle moved with very little resistance. It would not catch the hammers to lift them and drive a staple.

Tools

• Screwdrivers for prying
• Drill
• Hacksaw
• Rule
• MIG welder (optional)

Materials

• 1/4 inch steel (scrap)
• 1/8 inch steel rod
• Hot glue (in place of welding)

It is not necessary to remove any of the rivets that act as axles on which parts move or which hold the stapler together. I did not know that and drove two out. Doing that helped me understand how the stapler works and how to fix it. It also allows me to show you a photo you would not see if the trigger handle were still in place.

Looking inside the stapler from the back (with the trigger handle removed) you can see an obviously curved piece. This catches a recess in the two parallel hammers you can see under and below it. If the hammers can move too much toward the bottom of the photo the curved piece cannot catch the recess in the hammers, and the trigger handle moves with very little resistance.

Just below the hammers toward the bottom of the photo was a plastic spacer that held the hammers in place and kept them from going too low. Although that plastic seems to be ABS or something similar, it eventually cracked and broken pieces began to fall out. Not all of the pieces fell out, but I had to pry them out with a small screwdriver. I inserted a larger screwdriver between the bottom of the hammers and the frame of the stapler. Turn it a quarter turn to lift the hammers. Do your best to pry and scrape broken pieces of plastic out of the stapler.

The photo shows my completed fix. One piece of broken plastic was sufficiently intact that I could use a digital caliper to measure its thickness. It is a few thousandths of an inch greater than 1/4 inch. I cut a piece of scrap 1/4 inch steel almost 5/8 inch wide (the width of the cavity in the stapler at the hammers). I cut it just a little longer than 5/8 inch. I used a screwdriver to lift the hammers while pushing the steel forward so it was between the hammers and the frame of the stapler when finished.

My piece of 1/4 inch steel seems to remain in place while using the stapler, even when using it overhead or on a vertical wall. But, I am concerned the steel piece might be able to fall out. So, I drilled a hole for a 1/8 inch steel rod to keep the 1/4 inch steel in place. In the photo you can see the 1/4 inch steel with the 1/8 inch rod passing over its end to keep it in place.

I have a MIG welder. I welded the end of the 1/8 inch rod to the frame of the stapler. If I did not have a welder, I would drip some hot glue over the rod inside the cavity from the previous step. Neither the rod or the 1/4 inch steel seem to want to move around, but I have not used the stapler other than to test fire it a few times.

I would say my fix is pretty good, but there is one little annoyance. The trigger does not always catch on the hammers for the next staple. Hold the stapler front end down and release the trigger handle. It has been many years since I have used this stapler. I remember we sometimes had to do that when the stapler was new, too.