IMPROVED LADJUSTMENTS FOR SECURING GREATER ACCURACY IN TIME- KEEPERS.
Year: 1872

page_text: LETTERS PATENT to William Henry Wilkinson, of Great Hampton
Street, Birmingham, Electroplate Manufacturer, for the Invention
of "IMPROVED LADJUSTMENTS FOR SECURING GREATER ACCURACY IN TIME-
KEEPERS. ."-A communication from abroad by Henry Boehn James,
of Trenton, in the County of Mercer, and State of New Jersey,
United States of America.
Sealed the 12th November 1872, and dated the 16th May 1872.
PROVISIONAL SPECIFICATION left by the said William Henry Wil-
kinson at the Office of the Commissioners of Patents, with his
Petition, on the 16th May 1872.
I, WILLIAM HENRY WILKINSON, of Gt. Hampton Street, Bir-
mingham, Electroplate Manufacturer, do hereby declare the nature
of the said Invention for "IMPROVED ADJUSTMENTS FOR SECURING GREATER
ACCURACY IN TIMEKEEPERS," to be as follows:-
The Invention relates to the control of the vibrations and the motor
of chronometers and timekeepers, and it consists, first, in an equalizing
adjustment for the control of the mainspring of timekeepers having a

page_text: mainspring as a mortor. The object is effected by means of a link con-
nected with the stud, either on the frame of time or strike movements, or
on the surface of a stationary or going barrel, the stud being attached at
a point within the circle of the spring, and preferably as near the centre
as the spring can be wound; the centre coils, which are the weaker, being
dependent on the friction of the outer coils is not effected by the attach-
ment of the outside end, and by thus drawing it towards the centre a
gradual reduction of the leverage is produced and the effective portion
equalized according to the length of the spring; the coils are not
liable to bind and slip, nor the spring to unhook, and stopworks are not
required.
The Invention consists also in the further control of the mainspring of
those timekeepers having a going barrel for the mainspring, by confining
the open end of the barrel within the main wheel by means of a flange
on the former and a corresponding groove in the latter, to spring together,
having a stop in the wheel to hold the end of a spring stop formed of a
portion of the flange to maintain the face of the mainspring; and in case
the coiled spring should break, it would relieve itself upon the barrel,
which is thus allowable to reverse any number of turns and prevent
injurious effects upon the teeth of the wheel and the train.
The Invention consists also in the employment of a compensating coil
to control the vibrations of a pendulum and prevent the effects of
changes of temperature in those timekeepers having a pendulum to
govern the vibration. The object is effected by means of coiled laminae
of two metals of different expansion applied at or near the centre of
oscillation, and so constructed as to cause an upward movement of a
weight as that rod lengthens by heat, and a downward movement thereof
as it shortens.
The Invention consists also in further improving the said compen-
sation by making the weight adjustable to have more or less effect,
either by giving the outside end of of the coil on which the bob may rest
a proper angle, or preferably to have a horizontal arm on which the
weights is adjustable without disturbing the mean time regulation.
The Invention also relates to the control of the hair spring and balance
of those timekeepers having a hair spring and balance to govern the
vibrations, not only to prevent the effect of changes of temperature as a
principal or auxiliary compensation, but as an auxiliary adjustment,

page_text: isochronism of the semi-vibrations, and of the long and short vibrations,
and for producing an equilibrium escapement and a greater range and
speed in the balance. This object is effected by means of an intermediate
coiled spring attachment for the hair spring to alternate with the hair
spring spires, the centre coil being attached to a fixed stud. The coil
may be composed of one metal, and have a partial compensation effect,
but is preferable if composed of two metals of unequal expansion, such
as brass outside of steel when coiled, the vibrations being controlled by
mean time screws in the balance, thus adding the aforesaid adjustment
to the usual isochronous manipulations to improve and maintain a
uniform, accurate, and permanent adjustment to heat and cold,
isochronism, and different positions if required.
This Invention relates further to an adjusting stud for the coil or hair
spring only. It consists of a stud having a screw down through it, with
a square fitted to slide in a slot cut in the balance bridge or other
appendage, as required, the screw head being conical, and fitted into a
countersink in the square, and when the point of adjustment to the
diameter or isochronous condition of the spring and balance is obtained,
the edge of the slot is countersunk to maintain the adjustment and allow
the stud to be removed and replaced; the screw may remain in the stud
by having an aperture for it to pass through if required.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Henry Wilkinson in the Great Seal Patent
Office on the 14th November 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HENRY WILKINSON, of Great Hampton Street, Birmingham, Electro-
plate Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of May, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-fifth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said William Henry Wilkinson, Her special licence
that I, the said William Henry Wilkinson, my executors, administrators,
and assigns, or such others as I, the said William Henry Wilkinson, my
> executors, administrators, and assigns, should at any time agree with,

page_text: 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 "IMPROVED AD-
JUSTMENTS FOR SECURING GREATER ACCURACY IN TIMEKEEPERS,” a commu-
nication to me from abroad by Henry Boehn James, of Trenton, in
the County of Mercer, and State of New Jersey, United States of America,
upon the condition (amongst others) that I, the said William Henry
Wilkinson, 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 William Henry Wilkinson, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
This Invention relates to the control and adjustment of the main
spring, pendulum, and balance, constituting an improved mode of
securing greater accuracy and permanency in timekeepers.
The first part of the Invention consists in connecting the outer end of
the mainspring by means of a shifting link to a stud on the face of the
barrel, or on the frame of a clock, at a point within the periphery of the
barrel or the circle of the coils, and preferably nearer by a coil or so 2
than the outer coils can be wound, the object being not only to reduce
the leverage and consequently the spring power as the turns increase in
strength, but to free the coils from friction and binding against each
other, and from liability to break the end of the spring or unhook it.
The second part consists in the combination of the mainspring barrel 3
confined within the main wheel, securing them together by means of a
flange on the former, a portion of which may be used as a spring stop,
and a corresponding groove and catch in the latter, or other stops may.
be used, the object being to spring or hold the barrel and wheel firmly
together, and to impart the power of the mainspring to the train as 3
usual, and in case the mainspring should break to allow the barrel
to reverse within the wheel, and thereby prevent injury to the train.

page_text: The third part consists in the employment in connection with a clock
pendulum bob of a coil, or more than one, composed of several spires of
lamina of two metals differently affected by changes of temperature, such
coil or coils having the outer end extended (preferably across the bob)
and weighted, the coil and arm being so adjusted as to cause an upward
movement of the weight or bob, as the pendulum rod lengthens
by heat, and a downward movement as the rod shortens, for the
purpose of compensation for the effects of changes of temperature, the
weight being adjustable toward the coil to lessen the effect, and the con-
trary to increase it; small differences in mean time may also be adjusted
by raising or lowering the weight.
The fourth part consists in the employment of a flexible coil (composed
of brass lamina outside of steel if preferable) having a projecting arm,
to which the outer end of the hair spring is attached as a substitute for
the fixed stud, the stud by which the centre collet of the coil is secured
being as near the rim of the balance as may be, to have preferably as
short an arm as possible, and is placed in a position to alternate and
open its spires, and close them by the action of the hair spring and
balance; the coil should be sufficiently flexible as to retard the rate,
which is commonly fast in the long vibrations to increase it. The spring
coils may be opened as usual, an isochronous condition of the spring and
balance is thus made easy, and is more accurate and permanent than is
usual with a fixed stud on account of the isochronous semi-vibrations and
equilibrium escapement produced by the alternating action of the spring
and coil tending to maintain the adjustment under long continued action
and under changes of temperature. The equilibrium is maintained by
the coil and arm drawing the hair spring spires back as they lengthen
by heat, and the contrary in cold. To increase the speed and range of
the balance, and prevent outside agitation from affecting the rate, several
coils should be used requiring more substance, by which the tendency of
the coil is to react before the spring. The regulating curb may be used
opposite to the coil if compensation with a plain balance is desired,
but the mean time screws with an expansion balance may be preferable
to the curb, which, by widening the pins will have less effect, and the
contrary more effect, as the coil closes by reason of the brass outside of
steel, and the reverse in cold.
The fifth part consists in the combination of a screw stud of any de-
serintion and such adiustment as specified for the support of the hair

page_text: spring to remove and replace the same without disturbing the position of
the arm, as by placing it nearer to the spring spires the rate is retarded
in the long vibrations, and to turn the arm and end of the spring outward
increases the rate in the long vibrations.
To enable those skilled in the art to make and use the Invention, its
construction and operation is described as follow:-
First. The adjusting or shifting link for equalizing the strength of the
mainspring sufficient for all practical purposes, and used with or without
stop work, is made of tempered steel by preference, and arranged in a
recess formed in the surface of the barrel head or wheel to avoid inter-
ference with other parts. One end of the link is pivoted to a projecting
stud, with a screw similar to the gathering or slotted piece of stop work
or otherwise. The shifting end is bent down and inserted through an
opening in the barrel or otherwise, having a hook to attach the main-
spring in the usual manner with the arbor at the centre, the power thus
exerted is approximately equalized sufficiently for all practical purposes.
Second. The open end of the mainspring barrel has a small holding
flange turned outwards, with a portion of it sawed through and pro-
jecting out to form the maintaining spring, a corresponding groove and
catch is made in the main wheel, and has the barrel rim and catch spring
shaped into it, as the head is usually put in, the barrel being left free to
act as stated.
Third. The brass and steel lamina compensation coil for the pendulum
bob is composed of strips of about equal thickness, hard soldered together,
and coiled with either the brass or steel outside, and the spires free to
open and close. The centre coil is formed into a collet, and it is secured
to the bob by means of a friction pin or otherwise. The weight is made
adjustable in various ways. The top may be secured to a curved spring
bent under it to hold it on a thumbscrew, which is used to raise or lower
it to regulate for small differences in mean time, and with a similar
thumbscrew, both passing through the longer slotted arm of the coil,
the slot being of sufficient length to allow the weight to move to or from
the coil, and by means of the screw to secure it at the proper adjusted
point, other means may be used.
Fourth. The equilibrium isochronous compensation support for the 3
hair spring may be attached to the movement on the balance bridge if
the spring is above the balance, or to the plate if the spring is under the

page_text: balance. The end of the arm has a small split slide ring sprung over it to
clasp the hair spring, which is inserted on a surface of the arm, by which
it is held with its coils flat by forcing the ring out to the enlarged end
of arm, the spring or arm being curved to connect with each other if the
coil is above the balance.
Fifth. The combination stud may be made either by having a square to
pass through the balance bridge, with a screw to pass through the stud
and bridge, having the coil applied friction tight to the stud, or it may
in other cases be applied to a supporting bar, which may be screwed to
and removed from the plate.
Having now described the nature of my said Invention, and the
manner in which the same is to be carried into effect, I declare that
what I claim and desire to be secured to me by Letters Patent is,―
First. Attaching a mainspring to an adjusting or shifting link, which
is secured at a point within the circle of the spring coils to equalize and
adjust it, substantially as specified.
Second. The combination of the mainspring barrel, provided with
holding flange and stop, and the main wheel provided with corresponding
groove and stop to reverse and protect the train, substantially as specified.
Third. The compensation coil and weight for the pendulum bob of a
clock, substantially as specified.
Fourth. Attaching the hair spring to an equilibrium isochronous
compensation support, substantially as specified.
Fifth. The combination of the screw stud and coil adjustment, sub-
3 stantially as and for the purposes specified.
In witness whereof, I, the said William Henry Wilkinson, have
hereunto set my hand and seal, this Fourth day of November, in
the year of our Lord One thousand eight hundred and seventy-two.
WILLIAM HENRY WILKINSON. (L.S.)