Your 5 minutes web search has not revealed the theory
behind the gravity escapement, a form of remontoire,
a means to decouple the pendulum from the going train

The impulse to the pendulum is dependent upon two
locally invariant properties, the acceleration due to
gravity, and the mass of the Impulse Arms
(Dennison/Grimethorpe version) and pendulum.
The pendulum is not impulsed by the (weight driven
not spring driven) Going Train.

Brian Reay wrote in message
...
"Airy R. Bean" wrote in message
...
WRONG! Your comments relating to loss of accuracy are
WRONG in your assumption because I am considerng the
use of a gravity escapement.
The underlying problem is the same. Whatever the oscillating element
(balance wheel, pendulum etc) there is a problem with maintaining the
oscillation (by an impetus from the spring or weights via the drive chain)
and using energy from the oscillating element to release the escapement.
The former can be affected by spring tension (hence the use of the fusee
in
older watches, automatic winding in newer ones, and even the relative
success of the cylinder escapement) and the search over many years to
maximise the free swing portion of the oscillation (ie minimising the
energy
taken from the oscillating element to release the escapement.