FOR PERFECTLY DETACHING THE ESCAPE WHEEL OF CHRONOMETERS FROM THE INFLUENCE OF THE FRICTION AND INACCU- RACIES ARISING FROM THE MAIN SPRING, THE PIVOTS, AND THE TEETH, AND ALL THE OTHER WHEELS AND PINIONS IN THE MACHINE, DURING THE TIME OF ITS GIVING IMPULSES TO THE BALANCE, WHEREBY THE VIBRATIONS WILL BE MORE ACCU- RATELY AND UNIFORMLY SUPPORTED THAN BY ANY OTHER INVENTION HERETOFORE MADE PUBLIC, WHICH INVENTION WILL BE OF MUCH BENEFIT AND UTILITY FOR PRODUCING A SUPERIOR RATE OF TIME-KEEPING
Year: 1818

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PRIOR, late of Leeds, in the West Riding of the County of York, Watch-
maker, but now of Howard's Green, City Road, in the County of Middlesex,
Watchmaker, send greeting.
WHEREAS His present Majesty King George the Third, in and by His
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-ninth day of January last, for Himself, His heirs
and successors, did give and grant unto me, the said George Prior, His
special licence, full power, sole priviledge and authority, that I, the said
George Prior, my exors, adññors, and assigns, and every of them, by myself
and themselves, or by my and their deputy or deputies, servants or agents,
or such others as I, the said George Prior, my exors, adiñors, or assigns,
should at any time agree with, and no others, from time to time and at all
times hereafter during the term of years therein expressed, should and lawfully
might make, use, exercise, and vend, within England, Wales, and the Town of
Berwick-upon-Tweed, my Invention "FOR PERFECTLY DETACHING THE ESCAPE
WHEEL OF CHRONOMETERS FROM THE INFLUENCE OF THE FRICTION AND INACCU-
RACIES ARISING FROM THE MAIN SPRING, THE PIVOTS, AND THE TEETH, AND ALL
THE OTHER WHEELS AND PINIONS IN THE MACHINE, DURING THE TIME OF ITS
GIVING IMPULSES TO THE BALANCE, WHEREBY THE VIBRATIONS WILL BE MORE ACCU-
RATELY AND UNIFORMLY SUPPORTED THAN BY ANY OTHER INVENTION HERETOFORE
MADE PUBLIC, WHICH INVENTION WILL BE OF MUCH BENEFIT AND UTILITY FOR
PRODUCING A SUPERIOR RATE OF TIME-KEEPING;" in which said Letters Patent.
there is contained a proviso obliging me, the said George Prior, by an. instru

page_text: ment in writing under my hand and seal, particularly to describe and ascer-
tain the nature of my said Invention, and in what manner the same is to
be performed, and to cause the same to be inrolled in His Majesty's High
Court of Chancery within six months next and immediately after the date
of the said recited Letters Patent, as in and by the same, reference being
thereto had, will more fully appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
George Prior, do hereby describe and ascertain the nature of the said Inven-
tion, and in what manner the same is to be performed, by the Plan or
Drawing hereto annexed, and the following description thereof (that is to
say):-
This Invention consists of an additional wheel A, Figs. 1 & 2, with any
convenient number of teeth and other apparatus as follows:-The escape wheel
G, Fig. 2, which impels the balance in common chronometers must have the
same number of teeth as the additional wheel A, and is connected with the
train the pinion on its axis, as is usual. The pivot B is extended through a
plate or cock C; and the axis of the escape wheel A is in any of the cominon
way connected concentric with the pivot B of the wheel G (according to the
idea of the artist), and the other end of the axis or pivot turns in a pivot hole
in the plate R, or in a cock, as may be most convenient. Round the axis of
the wheel A is coiled a spiral or helical spring E, nearly as strong as the
power (communicated to the wheel G) from the main spring is able to wind
up to its proper situation, after having been set up a few teeth, before the
part L is put betwixt the guards a & b, whereby it will be prevented from
relaxing into its former situation. One end of this spring is fastened to a
piece or collet N, fitted on the axis of the wheel A, and the other end to F, on
the renovator M (seen also at Fig. 3), screwed to the pivot B, Fig. 2, which is
extended through the pivot hole in the plate or cock C. When the pivot B
is turned forward by the main spring through the wheels in the train, the
renovator is carried forward also, and winds up the spring E until one of
the teeth of the wheel G is stoped by a projecting pallet P on the letent
spring II, where it remains, with the renovating spring E wound up ready to
give an impulse to the balance from the tooth S of the detached escape wheel
A, seen in Fig. 1, striking against the pallet P, as applied to the common
chronometer escapements. The balance being put in motion, and the escape
wheel A being unlocked from the pallet on the detent spring at Q, the tooth
S of the wheel A will give the impelling pallet P, on the axis of the balance,
an impulse, and the instant the tooth S has quitted the pallet P, the tooth T
meets with and removes the lifting piece I, which is connected with the detent

page_text: spring at n, and removes the projecting pallet P from the tooth O of the wheel
b, seen more perfectly at Fig. 2, and alows it to pass one tooth forward, when
the renovator winds up the renovating spring as before. The wheel G cannot
escape more than one tooth, if the next was not to catch on the detent P by
any accident, as it would be prevented by the guard b, on the renovater M
coming in contract with the arm L, fixed on the axis of the escape wheel A;
also the arm L prevents the teeth of the escape wheel A from moving off the
end of the lifting piece I, by coming in contract with the guard a, on the
renovater M, until the escape of the tooth of the wheel G from the projecting
pallet P, on the detent spring H, has taken place, when the wheel b, by the
force from the main spring, passes on to the next tooth, taking along with it
the renovater M, with the guards a & b; and the guard a, being moved
forward from the arm L, it allows the escape wheel A, when applied to the
common chronometer's escapement, to rest against the locking pallet on the
detent spring Q, ready to give the next impulse to the balance; if applied to
the duplex escapement, the tooth will rest against the ruby cylender, as usual.
Observe, the arm L must not touch the guard b, when the tooth of the wheel
G is against the detent at P; if it did, the detent spring Q would partake of
the different pressures from the train by the teeth of the escape wheel A, at
the time the discharging pallet on the axis of the balance was unlocking it.
Fig. 3, the renovator M, with its guards a & b unscrewed from the pivot B,
that it may be the more distinctly seen.
Fig. 4, the socket, with the arm L containing a pivot hole c for the small
pivot on the end of the pivot B, which connects the axis of the
consentric taken off from the axis of the wheel A.
escape
wheels
Fig. 5, a spring V, screwed to the plate under the dial plate, with a project-
ing piece at U, which is extended against the back of the lifting piece at n; a
screw W, screwed through the spring V, whose end comes against a stud X,
fast in the plate, so that by screwing it further in or out, it allows the back of
the lifting piece n, Fig. 1 & 2, to fall further in, or not so far, for the purpose
of giving the projecting pallet P proper hold of the teeth of the wheel b.
Y, a lifting piece which comes out of the side of the watch, and acts against
the spring V at Z, in such a manner that if it is pulled it unlocks the projecting
pallet P, ou the detent spring II, from the tooth of the wheel G, as seen at O,
Fig. 1 & 2, by removing the lifting piece U of the spring V, which is in con-
tract with the lifting piece n, and when let go, resumes the situation by the
elastricity of the spring V, and again allows the detent P to stop the teeth of
the wheel G, as before. Any other contrivance to unlock the detent will
answer the purpose, if it only allows the detent II to resume its situation when