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This is a 5-digit revolution counter, probably made by Schäffer & Budenberg. It is intended for industrial use, and was generally used with steam engines, both locomotives and stationary engines. It is mounted in a round brass case with a small window in the front. An axle goes through it, and each full rotation of the axle increments the counter. The case has a small built-in lock to guard against tampering.
When unlocked, the case hinges open, allowing the counter to be reset. It does not really have a reset mechanism, but the piece to the left of the number wheels can be hinged out of the way, allowing the wheels to be slid apart and rotated independently.
The units number wheel is driven from the main axle via a clever eccentric gear mechanism that causes a 10:1 gear reduction, and also causes the units wheel to pause on each number. This is the same mechanism that is used in the carry mechanism of the Dacometer.
The counter has no markings of any kind so it is difficult to confirm when the counter was made and by whom. I have found a patent for a counter that bears a very strong resemblance to this one. It is by Eduard Stalmann, filed in 1879. He was based in Germany, but filed patents in Britain and the US. I assume that my counter is a slightly improved version of the one in that patent, differing only in the way the units wheel is driven. A Swiss patent from 1892 has an illustration of a counter with the eccentric gear drive, so it must have been well established by then.
I have not been able to find anything about Eduard Stalmann, except that the patent says he was based in Buckau, which is now a suburb of Magdeburg. This was an industrial centre, with companies such as Maschinenfabrik R. Wolf and Maschinenfabrik Buckau which both made steam engines, and Meßgeräte und Armaturenwerk Schäffer & Budenberg which made measuring instruments and fittings. It is very likely that this counter was made by Schäffer & Budenberg. I found that S&B made a steam engine counter in the 1870s which used the same way of driving the units wheel that was used in Stalmann's patent, and later illustrations showing a counter that looks similar to mine and which seems to use the eccentric gear instead. According to a recent book about the company, Eduard Stahlmann was an employee. I therefore believe that my counter was made by Schäffer & Budenberg, some time between 1880 and maybe 1920.
Included below is an excerpt from Schäffer & Budenberg's 1870 catalog describing their original steam engine counter. It uses the same drive mechanism shown in Stalmann's patent. Later articles and ads show the newer counter with what seems to be the eccentric gear mechanism.
The US patent by Eduard Stalmann in 1879 is for a very similar counter,
differing only in that it has a different mechanism to drive the units
wheel.
The 1892 Swiss patent has an illustration of a counter with an
eccentric gear to drive the units wheel.
| Patent | Filing date | Priority date | Name | Description |
|---|---|---|---|---|
| US 217,827 | 23-04-1879 | 22-07-1879 | Eduard Stalmann | Improvement in Counting-Registers |
| CH 5,185 | 30-06-1892 | 30-06-1892 | James Jaquet | Connection to a counter |
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