IMPROVEMENTS IN CHRONOMETER PROVISIONAL SPECIFICATIONTER AND OTHER LEVER WATCHES
Year: 1868

page_text: LETTERS PATENT to William Joshephat Thicthener, of Essex Road,
Islington, in the County of Middlesex, Chronometer and Watch
Manufacturer, for the Invention of "IMPROVEMENTS IN CHRONOMETER
PROVISIONAL SPECIFICATION left by the said William Joshephat
Thicthener at the Office of the Commissioners of Patents, with his
Petition, on the 8th December 1868.
I, WILLIAM JOSHEPHAT THICTHENER, of Essex Road, Islington, in
the County of Middlesex, Chronometer and Watch Manufacturer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
CHRONOMETER AND OTHER LEVER WATCHES," to be as follows (that is to
say) :-
My Invention has reference to a more simple and inexpensive method.
of forming escapements of chronometers and other lever watches, whereby

page_text: a double locking impulse power together with greater uniformity of
action in the several working parts thereof is obtained without necessi-
tating the employment of lubricating oil as at present, and consists,―
Firstly. In introducing into the impulse lever a gold stud or screw
secured to the same through the medium of a flat piece of steel notched
to receive the jewel and admit of mathematical accuracy of adjustment
with perfect solidity of the working parts.
Secondly. In forming the escapement wheel with locking teeth
having the points and stems of the said teeth cut at cross or acute
angles to the body thereof, and obviate banking pins, by the construction
of which a double impulse is given to the balance, and in the event of
the watch meeting with any jar or sudden shake (through the pin in
the roller-striking_the_points of the lever) the pallets are thereby
caused to run down the angles of the teeth of the escapement-wheel
and break the force of the concussion and admit of its falling softly and
propelling the pin forward whilst the main impulse power is still on,
by the action of which the vibrations of the said lever are brought
an equilibrium without disturbing or disarranging the
timing of the watch. The said escapement wheel being formed of gold,
and the lever and roller of tempered steel with ruby points, obviates
the necessity of employing lubricating oil.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Joshephat Thicthener in the Great Seal
Patent Office on the 4th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM 2
JOSHEPHAT THICTHENER, of Essex Road, Islington, in the County of
Middlesex, Chronometer and Watch Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eight day of December, in the year of
our Lord One thousand eight hundred and sixty-eight, in the thirty-second 8
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said William Joshephat Thicthener, Her special licence that
I, the said William Joshephat Thicthener, my exccutors, administrators,
and assigns, or such others as I, the said William Joshephat Thicthener,

page_text: of which the vibrations of the said lever are brought sooner to an
equilibrium without causing any disturbance or disarrangement in
the time of the watch by external motion or otherwise, the said escape-
ment wheel being formed of gold, and the lever and roller of tempered
steel provided with ruby pallets, obviates the necessity of employing 5
lubricating oil.
And, secondly. The introduction of an improved locking dittant into
marine and other chronometers for compensating for any interruption
or stoppage to the escapement by which uniformity of time is effectually
secured.
And, thirdly. In the construction and employment of a bi-coniform
spiral timing spring for producing a concentrical vibratory action and
-steady oscillation of the balance.
And in order that my said Invention may be more fully understood
and readily carried into effect, I now proceed to describe the same by aid 1
of the accompanying Drawings, reference being had to the letters and
figures thereon marked (that is to say)
Fig. 1 represents a front view of my improved double impulse escape-
ment wheel and jewelled lever shown on an enlarged scale; Fig. 2, a side
or edge view thercof; Fig. 3, an enlarged side view of the locking dittant 2
aforesaid separately shown; Fig. 4, reverse side view of same; Fig. 5, top
or plan view thereof; Fig. 6, underneath view; Fig. 7, a transverse vertical.
section taken through the dotted line in Fig. 3; Fig. 8, a longitudinal
section showing the adjusting screws and jewels; and Fig. 9, side view of
the bi-coniform spiral timing or pendulum spring. In each Figure the 2
same letters of reference denote similar corresponding parts.
A, A, impulse lever; B, B, the pallets; O, C, gold stud or screw
secured to the forked or notched end (C) of the said impulse lever;
D, D, ruby stone (with double curved point D') secured to the said stud
through the medium of a slot (as represented); E, E, the roller; F, F, 8
notch formed within the outer edge of the same receiving the points
of the said ruby; G, G, jewel acting within the fork of the lever for
giving an oscillatory movement to the same; II, H, escapement wheel;
I, I, stems of the locking teeth aforesaid; J, J, points of the same cut
from the angles K, K, and L, L, in the direction indicated by the dotted
lines; M, M, body of the dittant; N, N, arm of the dittant; O, O, gold
pivot screw upon which the arm works in connection with the body of

page_text: the dittant; P, P, jewel inserted within the arm through which the
gold pivot screw works; Q, Q, adjusting screw for setting the arm to
its proper depth in the escapement wheel; R, R, ruby locking stone
which acts in the escapement wheel teeth; S, S, guard or pipe of steel for
giving additional strength to the locking stone; T, T, reacting steel spring
screwed to the body and acting on the side of the arm aforesaid; U, U,
gold passing spring secured to the projecting portion of the arm on the
reverse side through the medium of the stud U'; V, V, gold guard screw
passing through a slot in the spring for controlling the action of the
same; W, W, steady pin screwed fast into a dovetailed cube of steel W
which slides in the grooved mortise X, X, within the dittant body for
adjustment as required; Y, Y, main screw for attaching the dittant to
the frame of the chronometer; Z, Z; bi-coniform spiral timing spring; Z',
points for attaching the same to the balance "cock stud" extending
outwards in a line with the centre convolution Z.
In conclusion to the foregoing description, I would here briefly note
that chronometers upon this principle will be proof against any vibrations
or concussions resulting from the discharge of a gun, or by storms at sea,
as the locking escapement prevents stopping or "tripping" which is the
case with the present chronometer.
Having now fully described and ascertained the nature of this my said
Invention, and the manner in which the same is to be performed and
carried into effect, I would have it clearly understood that I do not
intend to confine myself to the precise details herein-before set forth
and described, as the same may be otherwise varied without departing
from the general principle of this my said Invention, nor do I claim as
new and of my said Invention the exclusive use of the several parts,
combinations, and arrangements above referred to except when the same
are employed in and for the purposes of my said Invention, which I
hereby declare to consist,-
Firstly. In the double locking action of the escapement and mode of
obtaining the same in connection with the improved pallets, angular teeth,
gold stud, and ruby points aforesaid.
Secondly. In the construction and arrangement of locking dittants
having an adjusting arm, gold passing spring, regulating steady dove-
tailed slide and pin, pivot screw, and jewelled hole for same.

page_text: And, thirdly. The mode of forming and employing bi-coniform spiral
'springs in lieu of the ordinary timing or pendulum springs in the manner
and for the purposes herein-before set forth and described.
In witness whereof, I, the said William Joshephat Thicthener, have
hereunto set my hand and seal, this Twenty-fourth day of May, ₺
in the year of our Lord One thousand eight hundred and
sixty-nine.
Witness,
THOMAS M. CORNOCK,
Clerk to Messrs. Weatherdon & Co.,
Law Chambers,
-Chancery Lane. --
W. J. THIOTHENER.
I