AN IMPROVEMENT IN THE CHRONOMETER ESCAPEMENT OF A WATCH
Year: 1859

page_text: LETTERS PATENT to Charles Hanson, of Huddersfield, in the County of
York, Watchmaker, for the Invention of "AN IMPROVEMENT IN THE
CHRONOMETER ESCAPEMENT OF A WATCH."
Sealed the 17th February 1860, and dated the 27th August 1859.
PROVISIONAL SPECIFICATION left by the said Charles Hanson at the
Office of the Commissioners of Patents, with his Petition, on the 27th
August 1859.
I, CHARLES HANSON, of Huddersfield, in the County of York, Watch-
maker, do hereby declare the nature of the said Invention for "AN IMPROVE-
MENT IN THE CHRONOMETER ESCAPEMENT OF A WATCH," to be as follows :—
This Invention is intended to simplify the chronometer escapement of a
watch, and to dispense with the two springs usually employed at that part of
the movement. The Invention consists in the employment of a pivotteḍ
detent acting upon the escape wheel, which is made elastic in such a manner
and with such power as to dispense entirely with the use of the two springs
ordinarily employed as above mentioned in chronometers of the usual con-
struction.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Hanson in the Great Seal Patent Office on the
27th February 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HANSON, of Huddersfield, in the County of York, Watchmaker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Hanson, Her special licence that I, the said Charles Hanson,
my executors, administrators, and assigns, or such others as I, the said
Charles Hanson, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
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 "AN IMPROVEMENT
IN THE CHRONOMETER ESCAPEMENT OF A WATCH," upon the condition (amongst
others) that I, the said Charles Hanson, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and
seals, 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 Letters Patent.
NOW KNOW YE, that I, the said Charles Hanson, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement in writing, and on reference to the accompanying Drawings, that is
to say :-
This Invention is intended to simplify the chronometer escapement of a
watch, and to dispense with the two springs usually employed at that part of
the movement. The Invention consists in the employment of a pivotted
detent acting upon the escape wheel, which is made elastic in such a manner
and with such power as to dispense entirely with the use of the two springs
ordinarily employed as above-mentioned in chronometers of the usual con-
struction,
Such being the nature and object of my said Invention for "An Improve.

page_text: ment in the Chronometer Escapement of a Watch," I will proceed to describe
the same more in detail; and in order that my Invention may be perfectly
understood, I have annexed hereunto a Sheet of Drawings representing my
improved chronometer escapement (drawn about four times the actual size,)
and have marked the same with figures and letters of reference corresponding
with those in the following explanation thereof, that is to say :-
Figure 1 is a front elevation of my improved chronometer escapement, and
Figure 2 is a plan or horizontal view of the same, as seen from above.
a, a, is the ordinary balance wheel, provided as usual with a "hair spring"
(not shown in the Drawing). Upon the arbor b, b, of the balance wheel a
roller or pallet c, c, is fixed, provided with a notch or step d; e, e, is a crescent-
shaped detent fixed on an arbor f, f, the lower end of which is furnished with
an arm 9, 9, acted upon by a pin h, h, fixed in the roller c, c. The other end
of the arm g, g, vibrates between two stops i and k; l, l, is an escape wheel,
the arbor of which carries a pinion m, which is in gear with and is driven by
the ordinary movement of the watch.
The action of the escapement is as follows:-The mechanism being in the
position shown in the Drawing, with one of the teeth of the escape wheel 1, 1,
resting against the exterior or convex part of the detent e, e, suppose the
balance wheel a, a, to be swinging in the direction of its arrow, and the power
of the mainspring to be in communication with the escape wheel 1, 1, the
pin h, h, acting against the detent arm 9, 9, will withdraw the detent e, e, from
the tooth of the escape wheel, thereby unlocking the same. This tooth will
then pass through the interior or concave part of the detent e, e, and in doing
so, puts the latter again into the locking position ready for the next tooth.
The point of the first tooth passes into the notch d of the roller c, c, and is
carried on and released at the same instant that the next tooth is locked. On
the return swing of the balance wheel a, a, the pin h, h, passes the end of the
detent arm g, g, in the following manuer :-The lower pivot of the arbor f,f,
works in a small steel centre, the hole of which is elongated or slotted,
which allows the pin h to push the lower end of the arbor f outwards till the
said pin has passed the end of the detent arm, when the pressure of the escape
wheel on the detent immediately returns the detent and arm to their former
position.
Having now described the nature and object of my said Invention for "An
Improvement in the Chronometer Escapement of a Watch," together with the
manner of carrying the same into practical effect, I wish it to be distinctly
understood that I claim, as my Invention, the construction of a chronometer

page_text: escapement for watches as shown in the Drawing and above described, and more
particularly the detent e, with its arm g, and the pin h, and also the slotted
hole for the lower pivot of the detent arbor f.
'In witness whereof, I, the said Charles Hanson, have hereunto set my
hand and seal this. Twentieth day of February, in the year of our Lord
One thousand eight hundred and sixty.
Witness,
W. BARLOW, Patent Agent,
52, New Street,
Huddersfield.
CHARLES HANSON. (L.s.)