The Sticht plate was the first device of its type and was introduced in 1969 or 1970. It soon became very popular. The main drawback was that it tended to lock up unexpectedly. Later models had a spring, which prevented locking up, but ropes and and all sorts of other things would get caught in the spring.

Belay plates, or 'auto belayers' as they were sometimes called, took over from body belays around 1975 in the UK, a few years earlier on the continent. Fritz Sticht invented this version in the late 1960's and it was manufactured by Salewa. For a decade or so these plates were almost universal in their use, to the point where just about any belay plate, whatever its real name, was called a 'sticht plate'. some had two holes to take two ropes, and they could be different sizes.

The Salewa Sticht (/w spring), 9mm hole and 11mm hole, and is forged from aluminum alloy. A spring fits in a circumferential groove in the side of plate, and the groove is sheared and crimped closed over about one-fourth the circumference to provide an exit. The outer end of the spring is welded to the pervious coil to provide a smooth, closed loop. There is a steel bracket screwed to the top of the plate from below by a countersunk screw. A small dimple on the lower end of the bracket can hold the spring in the compressed position.

http://storrick.cnc.net/VerticalDevic...

http://storrick.cnc.net/VerticalDevic...