IMPROVEMENTS IN TIME- KEEPERS
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
YATES, of Preston, in the County of Lancaster, Watchmaker, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twelfth day of November, in the tenth year of Her reign.
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Yates, Her especial licence, full power, sole privilege and authority,
that I, the said Thomas Yates, my executors, administrators, and assigns,
and such others as I, the said Thomas Yates, my executors, administrators,
or assigns, should at any time agree with, and no others, from time to time
and at all times during the term of years therein mentioned, should and
lawfully might make, use, exercise, and vend, within England, Wales, and the
Town of Berwick-upon-Tweed, my Invention of "IMPROVEMENTS IN TIME-
KEEPERS;" in which said Letters Patent is contained a proviso obliging me,
the said Thomas Yates, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be
enrolled in Her Majesty's Пligh Court of Chancery within six calendar months
next and immediately after the date of the said in part recited Letters Patent,
as in and by the same, reference being thereunto had, will more fully and at
large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Yates, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, is particularly described and

page_text: ascertained in and by the following description thereof, reference being had to
the Drawings hereunto annexed, and to the letters and figures marked
thereon (that is to say) :-
My Invention of Improvements in Timekeepers relates to that descrip-
tion of timekeepers called pocket chronometers or watches, and consists
in constructing certain of the parts in an improved manner, so as very
much to reduce the friction of those parts, and thereby enable me to
make use of a main spring of a much less power, and yet at the same
time employ a balance of considerably greater weight than usual. By my
improved construction or arrangement of parts, I also propel the balance
a less number of beats to the minute, and at a much slower and more
regular speed. In fact, by my improvements I am enabled to employ a
balance of nearly three times the ordinary weight, with little more than half
the power usually found necessary for ordinary balances, and consequently, the
liability of the main spring and chain to break will be very much lessencil,
while a heavy balance, which has been found so essentially necessary for
keeping correct time, is obtained, and will be found to act in a most satisfactory
manner, without increasing the power of the main spring, or unnecessarily
interfering with the other parts of the watch or chronometer. The additional
power that would without any improvements be required for propelling the
heavy balance is more than compensated by the number of teeth in the
fourth wheel, and the size of the pinion in which it acts is so arranged that
every vibration of the balance is made to measure half a second of time.
The pallets of this escapement are also placed much wider apart than in
ordinary escapements, the lever being longer, and consequently having
greater power to operate upon the heavy balance, which I find it desirable to
make use of. The pallets are also made of greater length than usual, and at
a more obtuse angle, the teeth of the escapement wheel are also made at a
more obtuse angle, and being less in number while the wheel is nearly of the
same size, or rather larger than usual, they are of course further apart than
in the ordinary escapement wheel. By lengthening the lever, and altering the
angles of the pallets and teeth of the escapement wheel, the lever has more
power, a dead beat is produced, and the balance is propelled with a slower,
more steady, and uniform motion than usual. In order, however, that my
improvements may be fully understood, I have shewn in the accompanying
Drawings a side elevation and plan view of the ordinary lever escapement,
as well as my improved construction.
Figure 1 represents a plan view, and Figure 2 an elevation drawn upon an
enlarged scale, of an ordinary lever escapement. a is the escapement wheel,

page_text: with fifteen teeth, on the axle of which is a pinion with seven teeth taking
into a fourth wheel with the proper number of teeth, as is well understood.
6 is the pallet lever, and c the balance, made of brass or gold, which, owing to
the construction or arrangement shewn, is made to perform four beats to every
second, and consequently must not be made too heavy, otherwise the power
of the main spring will not be sufficient through the intermediate gearing to
overcome the resistance that would be offered to it. Now, as it is well known
in mechanics that we lose power as we gain speed, and as it is not essential
that the balance of a watch or chronometer should perform four beats to
every second, I consider that a great portion of the power is uselessly consumed
in causing the balance to move through a greater distance and at a higher
speed than is absolutely necessary. I have therefore, in the first place, altered
the number of teeth in the escapement wheel and its pinion, and also the
wheel into which it acts, so as to make the balance vibrate only once for every
half second of time, instead of four times every second. By this means I
find I economize a certain portion of the power of the main spring which
was formerly expended uselessly, and I further economize the power of the
spring or render it more available, by lengthening the pallet lever, it being it
also another principle in mechanics that by lengthening a lever it is rendered
capable of exerting additional power, or in other words, with a given power a
greater effect may be produced by increasing the length of the leverage.
Having thus reduced the amount of power necessary to actuate the various
parts of the watch, I am enabled to employ a main spring of much less power
than usual, and one therefore that will require less space; the watch may,
consequently, be made thinner than usual, and at the same time a consider-
ably heavier balance than can be employed with the ordinary construction
may be used.
Figure 3 is a plan view, and Figure 4 a side elevation of my improved
construction of escapement. a is the escapement wheel (as in the before-
described Figure), but made with only twelve teeth, the pinion below having
eight teeth, and the fourth wheel, which carries the seconds hand, and in which
the small pinion acts, as is well understood, has forty teeth. 6 is the pallet
lever, which, it will be seen, is much longer than in the other instance, and is
therefore capable of exerting much greater power on the balance c, which is
made of steel, and is nearly three times the weight of the ordinary balance.
The angle of the teeth of the escapement wheel is more obtuse, as is also
the angle of the pallets 1, 2, in my improved construction of escapement than
in the ordinary movement shewn in Figures 1 and 2. I would observe, that
I am aware that chronometers have been constructed in which the balance

page_text: makes three bents to every second; but I am not aware that any pocket
.chronometer or watch has ever yet been made to perform only two beats per
second, which I find quite sufficient. I would also remark, that a similar effect
may be produced by making the escapement wheel pinion with ten teeth
instead of eight, the number of the escapement wheel teeth remaining the
same, (viz.,) with twelve teeth, or the escapement wheel may be made with
ten teeth and the pinion with eight, and by altering the number of teeth in
the fourth wheel to correspond, a similar effect may be obtained; but I prefer
to produce the half second beat in the manner and with the numbers above
set forth and shewn in the Drawing, although I do not intend to confine
myself rigidly thereto.
In witness whereof, I, the said Thomas Yates, have hereunto set my
hand and seal, this Tenth day of May, in the year of our Lord
One thousand eight hundred and forty-seven.