IMPROVEMENTS IN WATCHES AND CHRONOMETERS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO CLOCKS AND OTHER TIME-PIECES
Year: 1856

page_text: LETTERS PATENT to Henry Stuart, of Liverpool, in the County of Lan-
caster, and Thomas Pritchard, of Runcorn, in the County of Chester,
Watch Makers, for the Invention of "IMPROVEMENTS IN WATCHES AND
CHRONOMETERS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO CLOCKS AND
OTHER TIME-PIECES."
Sealed the 27th June 1856, and dated the 8th January 1856.
PROVISIONAL SPECIFICATION left by the said Henry Stuart and
Thomas Pritchard at the Office of the Commissioners, of Patents, with
their Petition, on the 8th January 1856.
We, HENRY STUART, of Liverpool; in the County of Lancaster, and
THOMAS PRITCHARD, of Runcorn, in the County, of Chester, Watch Makers, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN WATCHES,
AND CHRONOMETERS, WHICH IMPROVEMENTS ARE ALSO APPLICABLE TO CLOCKS AND
OTHER TIME-PIECES," to be as follows:-
Our Invention consists of improvements in that part of watches and chrono-
meters known as the "escapement." We make the frame of the pallet of
an oblong piece of steel, and the pallet in the form of a triangle (which is
jewelled in the ordinary way); and about equally distant from each end, close

page_text: to the inside, we drill a hole to admit of the common pallet staff. We make
the lever of an oblong shape, and file it down on the top so as to leave a boss
on one end, and drill a hole parallel with the upper surface to contain the
feather spring. At the other end is a fork, with a hole drilled through the
end, in which we put a setting pin, perpendicularly with the upper surface of
the lever, and at the same end two other pins, one to strengthen the feather
spring to enable it to throw the pallet off the set, and the other forms a bridge
to keep it in its proper position, a hole being drilled near the centre of the
lover to admit the staff in the ordinary way. We make the balance staff
roller of a circular shape, with two inclined planes cut from the edge, meeting
in a point approaching the centre, so as to form a triangular notch, on one
side of which a hole is drilled to admit of the pin, which may be made round
or angular. The balance staff is fitted in the roller in the ordinary way. The
motion of the escapement is produced as follows:-The pallet wheel receives
its impulse from the spring in the usual way, and when the wheel rests upon
the pallet, the escapement is on the set which is thrown off by the vibration
of the balance, and the roller pin coming in contact with the feather spring,
takes the lever and pallet along with it until the pallet wheel tooth escapes
from the receiving pallet on to the impulse pallet, thus giving a direct and
continuous impulse to the balance, almost equal to the distance between the
ends of the pallet wheel teeth; but before the tooth of the wheel has com-
pleted its distance, the roller pin will have escaped from the feather spring,
and the inclined plane of the roller coming in contact with the setting pin of
the lever will have thrown the pallet back to its proper position to receive the
teeth of the wheel, thus giving the dead beat to the escapement, and that only
giving one motion of the pallet wheel tooth to every vibration of the balance.
The superiority of this escapement consists in its being almost entirely without
friction, so detrimental to the regular motion of any time-keeper. The dead
beat is another advantage it has over the escapements, as it does away with
the back action of the pallet wheel and all friction on the staff of the balance,
by which it is not so liable to stoppage from dirt and other causes incident to
the common escapement.

page_text: .
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Stuart and Thomas Pritchard in the Great Seal
Patent Office on the 7th July 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HENRY
STUART, of Liverpool, in the County of Lancaster, and THOMAS PRITCHARD, of
Runcorn, in the County of Chester, Watch Makers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Royal
Letters Patent, bearing date the Eighth day of January, in the year of
our Lord One thousand eight hundred and fifty-six, in the nineteenth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto us, the said Henry Stuart and Thomas Pritchard, Her special
licence that we, the said Henry Stuart and Thomas Pritchard, our executors,
administrators, and assigns, or such others as we, the said Henry Stuart aud
Thomas Pritchard, our executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN WATCHES AND CHRONOMETERS, WHICH IMPROVEMENTS ARE ALSO APPLI-
CABLE TO CLOCKS AND OTHER TIME-PIECES," upon the condition (amongst
others) that we, the said Henry Stuart and Thomas Pritchard, by an
instrument in writing under our hands and seals, or under the hand and seal
of one of us, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Royal Letters Patent.
NOW KNOW YE, that we, the said Henry Stuart and Thomas Pritchard,
do hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in and
by the following statement (that is to say) :-
-
Our Invention consists of improvements in that part of watches and chrono-
meters, known as the escapement. We use an extra pinion to give the full
seconds beat, and a minute wheel attached to the centre pinion tooth with
twice the number of teeth as each of the two ordinary ones. We make the
frame of the pallet of an oblong piece of steel or other suitable metal, and
the pallet in the form of a triangle, which is jewelled in the ordinary way;
and about equally distant from each other, close to-the inside of the pallet, we

page_text: drill a holo to admit of the common pallet staff. We make the lever of an
oblong shape, and file it down on the top side so as to leave a boss on one end
and drill a hole parallel with the upper surface to contain the feather spring.
At the other end is a fork, with a hole drilled through the end of it, in which
we put a setting pin perpendicularly with the upper surface of the lever, and
at the same end we put two other pins, one to strengthen the feather spring
to enable it to throw the pallet off the seat, and the other to form a bridge to
keep it in its proper position, a hole being drilled near the centre of the lever
to admit the staff in the ordinary way. We make the balance staff roller of
a circular shape, with two inclined planes cut from the edge, meeting in a
point approaching the centre, so as to form a triangular notch, on one side of
which a hole is drilled to admit of the pin, which may be made round or
angular. The balance staff is fitted in the roller in the ordinary way. The
motion of the escapement is produced as follows:-The pallet wheel receives
its impulse from the spring in the usual way, and when the wheel rests upon
the pallet the escapement is on the set, which is thrown off by the vibration
of the balance, and the roller pin coming in contact with the feather spring
takes the lever and pallet along with it until the pallet wheel tooth escapes
from the receiving pallet on to the impulse pallet, thus giving a direct and
continuous impulse to the balance almost equal to the distance between the
ends of the pallet wheel teeth; but before the tooth of the wheel has com-
pleted its distance the roller pin will have escaped from the feather spring,
and the inclined plane of the roller coming in contact with the setting pin of
the lever will have thrown the pallet back to its proper position to receive the
tooth of the wheel, thus giving the dead beat to the escapement, and that only
giving one motion of the pallet wheel tooth to every vibration of the balance,
this escapement gives the half seconds' beat with the ordinary train. To
obtain the full seconds we have recourse to an extra fourth pinion with half
the number of leaves the one has which is attached to the fourth wheel, so
that the drop of the smaller pinion is twice the distance of the larger one.
According to this arrangement, the seconds' hand would move twice as quick
as it ought to do; but to counteract that we have a complete vibration of tho
balance every second, consequently the works necessary to the going of the
watch are twice the time in running down, by which means we obtain a two-
day watch. The superiority of this escapement consists in its being almost
entirely without friction, so detrimental to the regular motion of any time-
keeper. The dead beat is another advantage it has over other escapements,
as it does away with the back action of the pallet wheel, and all friction on

page_text: the staff of the balance, by which it is not so liable to stoppage from dirt and
other causes incident to the common escapement.
Having thus fully described the nature and particulars of our said Invention,
and the manner of carrying the same into practical effect, we desire it to be
distinctly understood that we do not confine ourselves to the exact details
hercin set forth, as the same may be varied or modified without departing
from the principle thereof; but we claim the improved escapement motion
with dead beat, as herein described.
In witness whereof, we, the said Henry Stuart and Thomas Pritchard,
have hereunto set our hands and seals, this Fifth day of July, One
One thousand eight hundred and fifty-six.
HENKY STUAKI.
(L.S.)
THOMAS PRITCHARD. (L.S.)
Signed, sealed, & delivered by the within-
named Henry Stuart and Thomas Pritchard,
in the presence of
WILLIAM WILSON,
Liverpool.