I built this demonstration model of the Schmidt offset coupling following postings on the ”Spanner" internet mailing list back in 1998. Meccano enthusiast Edmundo Veiga from Brazil visited a now defunct web site called "Puzzling Gears", an illustration from which is shown on the left. This lead to the eventual construction of my model. Part of the correspondence is produced below.
The mechanism is fascinating to watch. I have altered the original IsoMec version (see illustration below) to show both vertical and horizontal movements but have used the same coupling mechanism. I believe the mechanism is used in offset litho printing machines to move the printing rollers away from the printing plates whilst the machine continues to run.
Well, having this perfect IsoMec drawing in front of me(shown above), I put
it together, concocted a suitable framework to hold the input and
output shafts - offset by about an inch and a half - then away we went
what a beauty! I must say this mechanism is a delight - its motion is a
treat to behold, it operates