At a period when many car clocks were unreliable and uncertain time-keepers, we enthused about the Kienzle battery-wound facia clocks. The first British car manufacturer to fit them as standard was Rover, with a separate battery on the 3-litre to ensure that the Kienzle didn’t stop if for any reason the car’s battery had to be disconnected.
It is interesting that Rolls-Royce, Bentley, Aston Martin, Ford and Vauxhall have joined Rover in fitting Kienzle clocks, which, on the Continent, are used by Audi, Opel, Taunus Ford, VW, N.S.U., Porsche, Mercedes-Benz and B.M.W. Kienzle started making car clocks over 40 years ago and a sales booklet issued by them recently shows a 1928 Mercedes tourer so equipped. Since then more than 10 million have been supplied to the Motor Industry. The makers claim that their clocks work accurately on 6 or 12 volts and that a 50% plus or minus variation does not affect their accuracy. Their average power consumption is under 200 microamperes (m.e.p.c.). The mechanism includes an electric magnet which winds up the main-spring about every 1½ minutes, a wheel train of polished steel pinions and cut brass wheels, and the Kienzle lever escapement using a hair-spring made of a temperature-compensating alloy, the oscillation cycle being 4/9th sec.
Some years ago we proved that a Kienzle clock would run accurately on a modest voltage by mounting one in a Meccano framework and powering it from a 4½-volt dry cell. The only disappointment was the discovery that it wouldn’t restart after being idle for a long period, the lubricant having hardened, which it isn’t economical to rectify. However, providing you keep your Kienzle clock in reasonably frequent operation it should be extremely reliable and accurate. Indeed, we are told that each one is checked for seven days on time-checking alone, the date of manufacture being stamped on each clock that passes this stringent test, which means that at the factory in Germany up to 120,000 clocks can be heard ticking away together.
Home-fitting instructions for the 2-in. (52-mm.) dia. and 2½-in. (60-mm.) dia. Kienzle clocks are obtainable from the Sole Agents, the Anglo Continental Clock Co. Ltd., 928, High Road, Finchley, London, N. 12.—W. B.