IMPROVEMENTS IN THE CONSTRUCTION OF CHRONOMETERS AND OTHER TIMEKEEPERS
Year: 1846

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, GEORGE
PHILCOX, of High Street, in the Borough of Southwark, Chronometor Maker,
send greeting
WHEREAS Пer present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, beaning date
at Westminster, the Twenty-fifth day of April, in the ninth year of ller
reign, did, for Iferself, Her heirs and successors, give and grant unto me,
the said George Philcox, Her especial licence. full power, sole privilege
and authonty, that I, the said George Philcox, my executors, administia-
tois, and assigns, and such others as I, the said George Philcox, iny exe-
cutors, 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 THE CONSTRUCTION OF CHRONOMETERS AND OTHER TIMEKEEPERS,"
in which said Letters Patent is contained a proviso obliging me, the said
George Philcox, by an instrument in writing under my hand and scal, par-
ticularly 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
inrolled in Her Majesty's High 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
aud at laige appear

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
George Philcox, do hereby declare that the nature of my said Invention, and
the manner in which the samo is to be performed, is particularly described
and ascertained in and by the following description thereof, reference being
had to the Drawings hereunto annexed, and to the letters and figuies marked
then con (that is to say) :-
=
These improvements in chronometers and other timekeepers consist in a
novel construction or adaptation of the spring or springs by which the
mechanism of the timekeeper is impelled. By this improvement I prevent an
eiror which exists in the ordinary construction of the springs of marine time-
keepers, arising from the variations of temperature and consequent expansion
01 contraction of the spring in different climates. Thus I effect by con-
structing my improved chronometer spring of two parts, or by adapting two
springs in conjunction, so that as one of the springs, or one portion of the
spring, expands or contracts from the variations of temperature, the other
spring or portion of the spring equally expands or contracts at the same time
and in the-same degree, but in an opposite direction, through which improved
construction or means the previously existing crior is effectually neutralized,
and the chronometer, if correct in all other parts of its construction, is enabled
to keep a uniform rate of going in all climates and under all temperatures,
which the ordinary arrangements or constructions of chronometer spings
could not do, and which has never been effected until I discovered the
improved mode of causing the spring to counteract its own defect.
In the accompanying Diawing I have shewn several views of a chiono-
meter spring constructed on my improved principle, but do not intend to
confine myself to that particular arrangement, as the same principle of a
compound sping may be carried out under different modifications.
Figure 1 represents in elevation, mounted in its bearings, a double helical
sping a and b, which is attached at its outer extremities to the forked bracket
oi stud c, and at us inner extremities is made fast by pinning to a collet or
adjustable bar d fixed upon the spindle or staff e; and f is the compensation
balance, likewise affixed to the staff. This attachment of the double spring is
better seen in the detached houzontal view of the staff and spring, at
Figure 2.
The same parts and arrangements as shown at Figure 1 are represented,
with the cock and plate, in the horizontal view Figure 3, and referred to by
similar letters.
Figures 4 and 5 represent the double helical spring complete and in action,
with the compensation balance diawn in section The upper portion of the

page_text: sping a, it will be seen, is in Figure 4 collapsed, whilst the lower portion of
the spring bis expanded. In Figure 5 the lower portion of the spring bis
collapsed, whilst the upper portion of the spring a is expanded, and as the
balance vibrates the clastic force of these two portions of the spring constantly
act in opposition to each other, and thereby neutralize the error which would
be caused by the variations of temperature as described above.
Having now described my improvements in the construction of chrono-
meters and other tumcheepers, I desire it to be understood, that I do not
confine myself to the adaptation of a helical spring or springs in the way
shewn, as the same pinciple might be carried out with convolute or spiral
springs But that which I claim as Invention, and desue to maintain under
the above in part recited Letters Patent, is, the employment of a double
spung to chronometers, so formed and adapted that whilst the one half of the
spring is opening, the other half of the spring shall be closing in the same
ratio, by which means I am enabled to neutralize the co of a chionometer
spring when acted upon by vanations of temperature.
In witness whereof, I, the said George Philcox, have hereunto set my
hand and seal, this Twenty-fourth day of October, in the year of our
Loid One thousand eight hundred and forty-six.