G1 stamp machine mechanism

This mechanism was developed by Associated Automation in 1970. The coil is a Machin multi-value and as you can see it is held in a Perspex cover. This screws up tight against a rubber seal to try to eliminate the damp. Later versions had this cover lined with cork to absorb dampness, but then you cannot see the roll, so not so useful.

The mechanism is "coin-freed". That is, by inserting a coin, the mechanism trip is freed allowing it to move if the drive weight is raised. The weight is raised not by inserting the coin, but by lifting the large flap cover. This action primes the machine. The coil carries 3000 stamps, 600 strips of 5 adding up to 10p, or 60 pounds in total.

Two other coil strips were used prior to this, each of five stamps, adding up to 5p and before that, 1s.