IMPROVEMENTS. IN WATCHES, CLOCKS, CHRONOMETERS, TIME-PIECES, AND ALL OTHER INSTRU
Year: 1854

page_text: LETTERS PATENT to David Tunks, of Accrington, in the County of
Lancaster, Watch and Clock Maker, for the Invention of "IMPROVEMENTS.
IN WATCHES, CLOCKS, CHRONOMETERS, TIME-PIECES, AND ALL OTHER INSTRU-
Sealed the 24th April 1855, and dated the 9th November 1854.
PROVISIONAL SPECIFICATION left by the said David Tunks at the Office
of the Commissioners of Patents, with his Petition, on the 9tli November
1854.
I, DAVID TUNKS, of Accrington, in the County of Lancaster, Watch and
Clock Maker, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN WATCHES, CLOCKS, CHRONOMETERS, TIME-PIECES, AND ALL OTHER
INSTRUMENTS FOR THE MEASUREMENT OF TIME," to be as follows:-
Instead of the usual pinion used for the propagation of motion from one
wheel to another, I propose to use a spiral screw or worm, by which I am
enabled to reduce the number of teeth in the wheels, to lessen the amount of
friction consequent thereon, to make the time-pieces go a much longer time
between winding-up than can be done by the present plans, and consequently
prevent derangement of the works by frequent winding-up.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Tunks in the Great Seal Patent Office on the 8th May
1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
TUNKS, of Accrington, in the County,of, Lancaster, Watch and Clock Maker,
send greeting..
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Royal
Letters Patent, bearing date the Ninth day of November, in the year of our
Lord One thousand eight hundred and fifty-four, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said David Tunks, Her special licence that I, the said David Tunks,
my executors, administrators,, and assigns,.. or .such others as I, the said
David Tunks, 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 "IMPROVEMENTS IN
WATCHES, CLOCKS, CHRONOMETERS, TIME-PIECES, AND ALL OTHER INSTRUMENTS
FOR THE MEASUREMENT OF TIME," upon the condition (amongst others) that I,
the said David Tunks, by an instrument in writing under my hand and seal,
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.
per-
NOW KNOW YE, that I, the said David Tunks, do hereby declare the
nature of the said Invention, and in what manner the same is to be
formed, to be particularly described and ascertained in and by the following
statement (that is to say) :-
=
.'
My Invention consists of the substitution of a worm or spiral instead of the
pinion, as now used, for giving motion from one wheel to another, by which I
gain, firstly, greater simplicity of construction, and consequently less liability
to wear and derangement; secondly, an encreased duration of motion, as
watches and time-pieces by this. contrivance can, be made to go over periods
of time from thirty hours to one month with once winding-up, which length
of time cannot be obtained by the present plans. I can use either one or

page_text: more worms or spirals in the 'same time-pièce instead of the pinion or
pinions, according to the nature of the time-piece to be made....
The nature and particulars of my said Invention will be clearly understood by.
reference to the accompanying Sheet of Drawings; in which the same letters
of reference are used to represent the same parts in each Figure., a repre-
sents the bottom plate of a watch; b, the centre wheel, which in this arrange-
ment has upright teeth, same as a contrate wheel; c, the pinion to which the
centre wheel is attached; d, the pinion which is driven by the upright teeth
of the centre wheel b; e is a small wheel, called the spiral wheel, which is fixed
to the arbour or spindle of the pinion d, and driven with the pinion by the
centre wheel 6; f is the worm or spiral, which is driven by the spiral wheel e;
g, the arbour or spindle of the worm or, spiral, to which is attached the escape-
ment wheel h; i is a small pottance or stud, which is screwed to plate a, for
the pivot on the end of the arbour or spindle of the pinion d to work in; there
being also a similar pottance or stud for the pivot on the opposite end of the
same arbour to work in, but which is not shewn..
.
In these Drawings I have only shewn one worm or spiral, which is attached
to the escapement wheel, but, as I have already said, more may be used. The
superiority of the spiral over the pinion, for the purpose of giving motion from
one wheel to another, may be thus illustrated :-The escapement wheel in the
ordinary lever watch is attached to a pinion of seven teeth; thus, the escape-
ment wheel will require seven teeth of the wheel that propels it in order to
make one revolution, whilst the same wheel attached to a worm or spiral can
be turned one revolution with one tooth of the wheel that propels it; thus
performing as much motion with one tooth as in the pinion arrangement
would require seven teeth; and by this saving. in the number of teeth the
spiral watch or time-piece can be made with fewer works, and consequently a
great reduction of friction.
Having thus fully described the nature and particulars of my said Inven-
tion, I desire it to be distinctly understood that I do not confine myself to the
exact details herein set forth, as such may be varied or modified without
departing from the principle thereof; but I' claim as my Invention, and which,
to the best of my knowledge and belief, has not been hitherto used within this
realm, the entire use of the worm or spiral for the purpose of propagating
motion from one wheel to another in all clocks, watches, time-pieces, or in all
instruments made and used for the measurement of time.

page_text: I also claim to make my time-pieces to beat from sixty to two hundred
beats, or more or less, per minute, as the nature of the time-piece may
require.
In witness whereof, I, the said David Tunks, have hereunto set my
hand and seal, this Fourth day of May, One thousand eight hundred
and fifty-five.
Signed, sealed,. and delivered by the within-
named David Tunks, in the presence of
E. J. HUGHES,
Patent Agent,
Manchester.
DAVID TUNKS. (L.S.)