The pin-lever escapement is a cheap, less precise form of the lever escapement. Vertical metal pins on the lever take the place of the jewelled pallets in a standard lever. It powered low-cost mechanical watches, such as Roskopf’s ‘proletarian watch’, until cheaper quartz watches took over.
How does a pin-lever escapement work?
In a standard lever escapement, the lever carries horizontal pallets made from jewels. In the club tooth lever escapement, those jewels are rubies. The pin-lever design drops them. Instead, vertical metal pins are fixed to the lever, and they do the same job. This is what makes it a cheap form of the lever escapement. There is a cost in performance. Metal pins create much more friction than jewelled pallets do. That friction is one reason these watches are less accurate timekeepers than a standard jewelled lever.
Where it comes from
Georges Frederic Roskopf built on an earlier pin design to develop what became known as the Roskopf escapement. He made it popular by using it in his low-cost ‘proletarian watch’, which is dated to 1867. The aim of that watch was a low price, and an escapement without jewelled pallets suited it well. His name stayed attached to the design. Today it is still called the Roskopf escapement, alongside names such as pin-pallet and pin-lever.
Were pin-lever watches ever jewelled?
Pin-pallet watches usually went without jewels. That matched the purpose of the design as a low-cost movement. There were exceptions, though. In the 1960s, Timex and Oris both made fully jewelled versions. Fully jewelled pin-pallet watches were the exception, not the rule. The design did not last. Once cheaper quartz watches became popular, watches with this escapement almost completely vanished.
Checked