Thursday, October 29, 2020

Riveting

When I was a high school in the 1960s, we did one hour of metal-work every week. One of our first projects was to make a lunchbox out of sheet metal. Part of the lunchbox had to be riveted together using a hammer and a rivet punch to flatten the head of the rivets. This was a tricky task, as if the punch was hit at a slightly incorrect angle, the rivet would bend over, rather than forming a nice round head. The struggle to get it right put me off riveting for life.

Last week, more than fifty years after my bad experience with rivets, I assembled a garden shed from a flatpack imported from China. The instructions were easy to follow, but parts of the door had to be riveted together. I bought a riveting tool for a few dollars (also imported from China). I was amazed at how easy it was to use. What a clever tool. And what a clever man who invented it.

When I did some research, I was surprised at how long blind rivets had been used. In 1916, a navy engineer in the UK called Hamilton Wylie filed a patent for an "improved means of closing tubular rivets" (granted May 1917). In 1922 he joined the British aircraft manufacturer Armstrong-Whitworth Ltd to advise on metal construction techniques. He continued to develop his rivet design with a further 1927 patent that incorporated the pull-through mandrel, which allowed the rivet to be used blind.

By 1928, the George Tucker Eyelet company of Birmingham England produced a "cup" rivet based on the design. It required a separate mandrel and the rivet body to be hand assembled prior to use. The company later modified the rivet design to produce a one-piece unit incorporating mandrel and rivet. This product was later developed in aluminium and trademarked as the "POP" rivet.

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