Pin-lever watch
From Wikipedia, the free encyclopedia
A pin-lever or pin-pallet escapement is a lever escapement used in mechanical watches that uses metal pins on the pallet of the lever, rather than jewels. The pallet is the part of the lever that engages the escape wheel, which is critical for transferring the energy stored in the spring to the balance wheel. Jewelled pallets can be made much smoother than metal pins and therefore lose much less energy due to friction. The metal pins also wear much quicker.
The pin-lever escapement is also called Rosskopf by the name of its inventor Georges Frederic Roskopf.
Although this technically includes some jeweled watches (the Timex 21 Jewel was an example of a pin-lever design with added jewels), the most common meaning is an inexpensive watch using plain steel pivots rather than jeweled bearings. While these watches could be more rugged than a jeweled mechanical watch, they wore far more quickly and were less likely to maintain a constant rate.
By 1980 quartz watches dominated the market, and low-end mechanical production largely ceased.