The left diagram depicts the Robin remontoire invented by
Robert Robin of France. In 1772 he presented a paper to the Academie Royale de Sciences on
his remontoire for which he is best known. It is based upon the Christiaan Huygens endless
rope system invented by Huygens in 1658 as means for maintaining power to a clock
mechanism while it is being wound (an early type of maintaining power system), see
right diagram. Robin's genius was to make this endless rope maintaining power system automatic
through one of the wheels in the Huygens system being powered by the main going
barrel and released periodically by a detent, connected to the Huygens remontoire weight.
This relatively simple, reliable system allowed a clock to have the portability of a
spring-driven clock with the constant power of a weight driven clock. It also serves the
same purpose as any other train remontoire of isolating the escapement from the
inaccuracies found through the rest of the clock train, and in the case of a tower clock,
the effects of weather on the exterior dial being transmitted backward to the escapement.
The remontoire works as follows:
The remontoire driving weight, a, drives wheel, e,
through the chain, i, wound around its pulley, g,
and cog, e. This wheel drives the escapement wheel. During this
time wheel, f, is locked and thus weight, a,
will descend as the escape wheel turns. After a time the weight will depress pad below it
attached to lever, b, which is attached to vertical rod, c.
This rod is connected to lever, d. At the end of lever, d,
is a detent which blocks a pin attached to the rim of wheel, k.
The small counterweight, l, keeps the slack chain from becoming
entangled. When pad is depressed by the weight the detent locking the wheel, k,
is raised out of the way of the pin on the wheel rim allowing wheel, k,
driven by the movements main weight or spring to rotate. This raises the remontoire drive
weight, a, allowing lever, b, to rise; lowering the detent back
into position to block the pin on the rim of wheel, k after one
revolution.
Left diagram from Turmuhrwerke, Bernard Schmidt; right Horloger,
Roret