Model: 050 ??? Ratchet Wheels and Drivers (Boston) or Pawl Drives & Stops (Newark) ???
The top model has an almost continuous motion. Watch action of stop pawl. The driver, having both pawls attached to it, acts as both stop and driver alternately. In the bottom model, the stop and driving pawls are independent. This is used in many ways, particularly in connection with counting devices on automatic machines.
[Virginia Downward & William M. Clark, 1930]

[Editor’s Note: Ratchet mechanisms are like diodes and digital devices in electronics; limiting motion in one direction and permitting only discrete motions. Franz Reuleaux was very much intrigued with ratchet mechanisms so much so that his collection as produced by Voigt in Berlin contained 26 ratchet models in the N series not to mention 12 models in the X series on escapements. He also called some ratchet mechanisms click wheels. Clark designed this model after Figures 75, 76, 238, 240, 241 in Henry T Brown's 1868 catalog of mechanical movements. See also Clark model 50. FCM]

Francis Moon 2005-00-00

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