Model: S37 Four-bar Linkage with Parallelogram Straight-line Mechanism
This model is in essence a four-bar mechanism with a parallelogram or 'pantagraph' copying extension not unlike the Watt steam engine straight-line mechanism. The Voigt catalog calls this mechanism an 'Ellipse linkage with stork's bill', (Storchschnabel, in German) This description is not clear since the four-bar is not an exact ellipse drawing mechanism. The 'stork's bill may refer to Model S-36 which also has a parallelogram extension and looks like a pecking bird in motion.

Francis Moon 2003-07-01

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