Im- PROVEMENTS IN CHRONOMETERS, WATCHES, AND TIMEKEEPERS
Year: 1858

page_text: LETTERS PATENT to Henry Brocklebank, of Coventry, in the County of
Warwick, Watch and Chronometer Maker, for the Invention of "Im-
PROVEMENTS IN CHRONOMETERS, WATCHES, AND TIMEKEEPERS."
Sealed the 17th September 1858, and dated the 19th March 1858.
PROVISIONAL SPECIFICATION left by the said Henry Brocklebank at
the Office of the Commissioners of Patents, with his Petition, on the
19th March 1858.
I, HENRY BROCKLEBANK, of Coventry, in the County of Warwick, Watch
and Chronometer Maker, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN CHRONOMETERS, WATCHES, AND TIMEKEEPERS," to be as
follows:-
I construct the detent spring of a chronometer or other timekeeper of a
curved form, and I make the passing or relieving spring of round wire,
hammered or flattened if necessary. I place the stop pin in the detent in a
horizontal position, or in the same plane as the escape wheel. The balance
arbor is furnished with one roller or disc, in the side of which a jewelled pallet
is fixed, and which roller also carries a pin for lifting the detent. I place a
centre seconds hand below or behind the hour and minute hands, and I mount
it on a tube or collar, which turns loose upon the boss of the hour wheel; it
has a wheel attached to it, which is driven by an intermediate pinion receiving
its motion from an extra fourth wheel or a wheel carrying a pinion driven by the
'third wheel, or other convenient wheel of the watch or chronometer. This
intermediate pinion also drives another wheel carried by a lever or sliding
plate, which wheel carries an independent seconds hand, which can be
stopped at any time by moving the lever or slide without stopping the watch,

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Brocklebank in the Great Seal Patent Office on the
17th September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BROCKLEBANK, of Coventry, in the County of Warwick, Watch and Chrono-
meter Maker, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Nineteenth day of March, in the year of our Lord One
thousand eight hundred and fifty-eight, in the twenty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Henry Brocklebank, Her special licence that I, the said Henry Brockle-
bank, my executors, administrators, and assigns, or such others as I, the
said Henry Brocklebank, 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 "IMPROVE-
MENTS IN CHRONOMETERS, WATCHES, AND TIMEKEEPERS," upon the condition
(amongst others) that I, the said Henry Brocklebank, 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 Henry Brocklebank, do hereby declare
the nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, reference being had to the accompanying Drawing, and to
the figures and letters marked thereon, that is to say :-
I construct the detent spring of a chronometer or other timekeeper of a
curved form, and I make the passing or relieving spring of round wire,
hammered or flattened if necessary. I place the stop pin in the detent in a
horizontal position or in the same plane as the escape wheel. The balance
arbor is furnished with one roller or disc, in the side of which a jewelled pallet
is fixed, and which roller also carries a pin for lifting the detent. I place a

page_text: centre seconds hand below or behind the hour and minute hands, and I
mount it on a tube or collar which turns loose upon the boss of the hour
wheel. It has a wheel attached to it which is driven by an intermediate
pinion receiving its motion from an extra fourth wheel or a wheel carrying a
pinion driven by the third wheel, or other convenient wheel of the watch or
chronometer. This intermediate pinion also drives another wheel carried by a
lever or sliding plate, which wheel carries an independent seconds hand which
can be stopped at any time by moving the lever or slide without stopping the
watch, and again started when required. The Invention is applicable to fixed
timekeepers and to portable timekeepers as watches and chronometers.
Figure 1 of the accompanying Drawing is a plan of a chronometer escapement
constructed according to my Invention; Figure 2 is a side view of the same
with the escape wheel removed. These and the other Figures are drawn on a
large scale to render the parts more visible. A is the escape wheel of the
ordinary form; B is the detent spring of a curved or bent form; C is the
passing or relieving spring which may be made in the ordinary manner or of a
small wire of steel or gold or other suitable material flattened by hammering or
rolling. This spring C projects a little beyond the detent spring B in the
usual manner, and is fixed to it by a screw b and steady pin; D is the verge
or staff or spindle of the balance; E is a disc or "roller" of steel or other
metal fixed on the verge. This roller has an angular notch, one side of which
serves as the pallet for receiving the impulse from the escape wheel; or a jewel
may be fixed in the roller to act as the pallet. For this purpose I drill a hole
in the edge of the disc or roller, and insert a cylindrical jewel pin, which
is ground flat on one side to serve as the pallet. Figure 3 is an edge view of
the roller with this jewel pallet m; Figure 4 is a plan of the same. A small
hole is drilled through the roller at the end of the pallet to facilitate its
removal when necessary; e is a pin fixed in the roller E, which lifts the
spring C and detent spring B when the roller revolves in the direction of the
arrow, and presses back the passing spring C when revolving in the opposite.
direction. The pin e may be cylindrical or it may be semi-cylindrical, so as
to allow the point of the spring C to leave it at the angle or junction of the
cylindrical with the flat surface.
One part of the detent spring B projects below the passing spring C, and
rests against a banking pin or stop a, fixed in the plate F. In this enlarged
part is fixed a jewel, stop pin, or pallet d, which forms the stop for the escape
wheel A. This stop pin d is in the same plane as the roller E and escape
wheel A, and is fixed in a hole or aperture in the spring B; the action of the
escapement is the same as that of the ordinary chronometer escapement.
As

page_text: the balance on the verge revolves in the direction of the arrow, the pin e comes
in contact with the passing spring C, and bends the detent spring B and draws
the stop pin d away from the wheel A, which immediately begins to move
in the direction of its arrow; one of its teeth falls against the pallet of the
roller E, and gives the impulse to the balance. Before this tooth leaves
the pallet the pine has passed or escaped from the end of the spring C, which
returns with the detent spring B to the banking pin a; the stop pin d then
catches and stops the next tooth of the wheel A as the acting tooth leaves the
pallet of the roller E. As the balance swings back in the contrary direction
to the arrow the pin e passes the passing spring C without affecting the detent
or escape wheel.
In the ordinary chronometer escapement, in lieu of the pin e a small tooth
or pallet fixed on a separate roller or disc on the verge is employed. If either
this roller or the roller E is shifted on the verge, the adjustment is lost, and
great care is required in again adjusting them in their proper relative positions,
but by employing the pin e fixed in the roller or disc E, the adjustment is
always preserved correct. The bent or curved form of the back part of the
detent spring B enables me to obtain a long spring in a small space, which is
particularly advantageous in pocket chronometers and others where large
dimensions are objectionable. The mode of applying the stop pin d is con-
venient and well adapted for a jewel stop pin. In lieu of a notch or a pallet
in the edge of the roller E, the pallet may consist of a pin of semi-cylindrical
or other suitable form fixed in the roller E, as shewn at f in plan in Figure 5
and in elevation in Figure 6. This pin is made shorter than the pin E, and
placed nearer to the circumference of the roller which is then placed in a
different plane to the escape wheel A. Figure 7 is a plan, and Figure 8 is a
side view partly in section, of a portion of a watch with centre seconds hand
constructed according to my Invention. I may observe that by a centre
seconds or centre seconds hand, I mean a seconds hand which revolves
about the same axis or concentric with the minute and hour hands of the watch
or timekeeper. In the ordinary constructions of centre seconds, the hand
is mounted on a central arbor or spindle, which passes through the tubes
which carry the minute and hour hands. In my improved arrangement the
minute and hour hands are mounted on separate tubes and driven in the
ordinary manner, and the centre seconds hand is mounted on another short
tube fitting freely outside the hour hand tube or boss.
In Figures 7 and 8, a is the arbor of the fourth wheel or of the wheel
which carries the ordinary seconds hand in an ordinary watch.
I place a
wheel 6 on this arbor, and an equal wheel d on the tube which carries the

page_text: centre seconds hand, and I place an intermediate pinion or wheel c, which
geers into both the wheels b and d, and thus causes the wheel d and the
centre seconds to revolve at the proper speed and in the proper direction.
As the intermediate pinion c has merely to transmit the motion from the
wheel b to d, its diameter and number of teeth are unimportant, and it may
be made as large or larger than the wheels b and d, if desired. The wheel b
may pass under or over the wheel d if desired, the pinion c being made long
enough to geer into both. e is another wheel of the same diameter and
number of teeth as b and d, and geering into the same intermediate pinion c,
and carrying another seconds hand, which may be in the usual position
occupied by a seconds hand on the dial. This wheel'e may pass under the
wheels and d, and it is so shewn in the Drawing. The arbor of this wheel e
is mounted on a lever f, which turns on a pin or screw at g, while its end
projects through the case of the watch. By pushing the end of this lever in
the direction of the arrow, the wheel e is moved out of geer with the pinion c,
and its motion then ceases. I thus obtain an independent seconds hand
which can be put in geer or stopped instantly. The extent of motion of the
lever is limited by fixed pins or stops. If a centre seconds hand is not
required, an ordinary seconds hand may be placed on the arbor a, still
retaining the pinion c, and wheel e, and the independent seconds hand as
before. As already mentioned, the diameter of the pinion or wheel c may
vary, and in Figure 9 I have shewn a plan of a watch, in which it is of about
the same diameter as the wheels b and d, and all three wheels are in the
same plane. These wheels are of somewhat smaller diameter than the hour
wheel h, but when the pinion c descends past the hour wheel to geer with the
wheel e at a lower level, as in Figures 7 and 8, the hour wheel / is made
small enough for its teeth to be out of the reach of the pinion c. An ordinary
seconds hand might be placed on the arbor of the wheel b, but this is super-
fluous, as the centre seconds hand is always in motion, and answers the same
purpose. This centre seconds hand may, however, be made independent by
mounting the wheel c on a lever, and moving it in and out of geer with the
wheel 6 or d, or both. In this case an ordinary seconds hand on the arbor
of the wheel b will be advantageous. The centre seconds may be driven
from the third or other wheel of the watch, if preferred, taking care to give
it the proper velocity and direction.
Thus, Figure 10 is a plan of an arrangement in which a wheel c is fixed on
the arbor of the third wheel, and communicates the motion to a pinion d
on the tube of the centre seconds hand. A very slight spring may be made
to bear upon the tube or wheel or other part of the centre seconds hand to

page_text: prevent it from overrunning by its momentum, and a light spring may also be
applied to prevent the independent seconds hand from moving when it is
thrown out of geer.
These arrangements of the centre seconds and also of
the independent seconds hands are applicable to other timekeepers as well as
watches.
Having now described the nature of the said Invention and in what
manner the same is to be performed, I wish it to be understood that what
I claim is,
First, constructing the detent springs of chronometers of a bent or curved
form, as herein-before described.
Second, the improved mode, herein-before described, of applying the stop
pin to the detent spring of chronometers, also the combination of such mode
of applying the stop pin with the bent or curved detent spring, herein-before
described.
Third, constructing chronometer escapements with the pin e for acting on
the passing spring fixed in the disc or roller E, which receives the impulse or
which carries a pallet or a pin which receives the impulse, as herein-before
described in reference to Figures 1, 2, 5, and 6; also the combination of
either of these arrangements with the aforesaid curved or bent detent spring,
and the aforesaid mode of applying the stop pin, or either of them.
Fourth, the mode of fixing the jewel pallet in the roller or disc E, as
herein-before described.
Fifth, constructing watches and other timekeepers with a centre seconds
hand mounted on a tube or collar placed over or outside the tube or boss of
the hour hand, as herein-before described.
Sixth, the improved mode or modes, herein-before described, of communi-
cating motion to the centre seconds hand.
Seventh, the mode of constructing and arranging the independent seconds
hand, herein-before described.
Eighth, the combination of the centre seconds hand and independent
seconds hand, as herein-before described.
In witness whereof, I, the said Henry Brocklebank, have hereunto set
my hand and seal, this Eleventh day of September, in the year of our
Lord One thousand eight hundred and fifty-eight.
HENRY BROCKLEBANK. (L.S.)