Improvements in Chronograph Mechanism.
Year: 1895

page_text: Date of Application, 8th May, 1895
Complete Specification Left, 7th Feb., 1896-Accepted, 21st Mar., 1896
PROVISIONAL SPECIFICATION.
Improvements in Chronograph Mechanism.
JAMES MCNEIL, Watchmaker and Jeweller. 34 Brymmer Street Greenock,
THOMAS MONTGOMERY. Watchmaker, 34 Brymuer Street Greenock do hereby
declare the nature of this invention to be as follows:-
In this chronograph the hands can be started, stopped, & brought to zero, either
by blowing through a tube, or by pressing a knob or button. With the ordinary
chronograph mechanism more power is required to actuate the hands than can be
conveniently applied by blowing, the greater part of this power is taken up by
raising the levers, which actuate the hands.
In our chi onograph the said levers are raised by means of a mainspring & traid
of wheels, thus reducing the amount of external power required.
We also have a cam & roller for stopping the balance in such a position that it
will start easily when required.
The action of our chronograph is as follows:-A ratchet wheel carrying a disc
with notches in its edge, is rotated in the usual manner by means of a lever and
click.
The number of notches in said disc is one third of the number of teeth in the
wheel which carries it.
Two seperate levers are actuated by means of the notches in the disc. One of
the levers is for the purpose of stopping and starting the going mechanism. The
other for stopping and starting the chronograph train. The levers have each a
stud and roller. Those rollers run on the edge of the disc.
When the chronograph hands are to be started from zero, the wheel carrying
the disc is moved forwaid one tooth as before dosoribed, one of the notches in the
disc comes opposite the roller on the lever, for stopping, and starting the going
mechanism. The roller falls into the notch and the lever springs back from the
balanco staff, and allows the going tinin to start. The chronograph hands being
cairied by the going tram also start. At the same time, the othet lever is raised
by its roller coming out of a notch in the disc. On this lever being raised,
one of the pins which is fixed in the sunil, or cam, which 18 turned by the
chuonograph traiu, is allowed to pass. The said sunil or cam revolves about seven
eights of a turn, and in doing so, raises the levers which actuate the chronograph
hands. Another pin in the bail or cam catches the lover, aud prevents the snail
oi cam from tuining further till the chionograph hands are again to be brought to
zero. When the wheel and disc is moved forward another tooth; the lever for
stopping and starting the going mechanism is raised out of the notch, and a roller
at the end of said lever is brought into contact with a cam on balance staff, thus
stopping both going train and chronograph hands. The cam being of such a shape
as when the roller comes in contact with it, the balance is held in such a position,
that when the rolle 18 again moved away from the cam, the balance will vibrate
without any danger of setting, as it might do if the balance was stopped near a
certain point.
When the wheel and disc moves forward another tooth, the lever for stopping,
and starting the chronograph train, falls into the position it occupied when the
hands were at 7e10. The pin in the snail or cam which the lever caught is now
allowed to pass, and the snail or cam revolves about one eighth of a turn allowing

page_text: the levers which actuate the chronograph hands to drop, and bring the hands to
zero, by means of cams such as are used in other chronographs.
The levers which actuate the chronograph hands, are furnished with rollers
which run on the cams.
Dated this the Twenty-fifth day of May 1895.
JAMES MCNEIL,
THOS. MONTGOMERY,
34 Brymner Street, Greenock.
Improvements in Chronograph Mechanism.
We JAMES MONEIL and THOMAS MONTGOMERY both of Thirty-four Brymner
Street, Greenock in the County of Renfrew, Scotland, Watchmakers do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This chronograph (though it can be actuated in the usual manner by pressing a
knob or button) is specially designed so that the chronograph hands can be started,
stopped and brought to zero by blowing through a tube. With the ordinary
chronograph mechanism more external power is required to actuate the hands than
can be applied by blowing. A considerable portion of this power is taken up in
raising the levels which actuate the hands. The principal object of our invention
14 to reduce the amount of power thus required. This object we attain by causing
the said levers to be raised by means of a mainspring and train of wheels, instead of
raising them by external pressure as in other chronographs.
The action of our chronographs mechanism is as follows-A ratchet wheel
carrying the disc with notches in its edge is 10tated in the usual manner by
incans of a lever K and click P. The number of notches in said disc is one third
of the number of the teeth in the ratchet wheel. Two separate levers G and H are
actuated by the notches in the disc J. The lever G stops and starts the
chronograph train which lifts the levers D E and F and the lever H stops and
starts the going mechanism. The levers G and H have each a roller which runs on
the edge of the disc J. Another view of the lever G is given at Fig. 4.
Fig. 1 shows the position of the levers disc and cams when the chronograph
hands are at zero and the going mechanism stopped. K is the lever with the
click P which rotate the ratchet wheel and disc J. L is a cylinder fitted with a
piston and piston rod and a tube is attached to the cylinder at M. When air is
blown from the mouth the piston is forced towards the lever K and the piston rod
coming in contact with the lever K presses it forward and the click P pressing on
the teeth of the ratchet wheel causes the said wheel and the disc J to rotate.
When it is desired to work the chronograph by pressing a knob or button the
cylinder may be removed and a knob or button with a rod attached can be put in
its place. When the chronograph hands are to be started from zero the ratchet
wheel carrying the disc J is moved forward one tooth (as before described) one of
the notches in the disc is thus brought in front of the roller in the lever II the
roller diops into the notch and the end of the lever H with the roller Q springs
back from the cam on the balance staff thus allowing the going train to start.
The chronograph hands also start as the heart shaped cams which carry the hands
are fitted loosely to arbours driven by the going mechanism and have friction
spungs pressing on those arbours. At the same time and by the same movement
of the disc J the lever G is raised by its roller coming out of a notch in the
disc J the pin in the snail or cam C which was held by the end of the lever G 18

page_text: allowed to pass and the suail or cam C (being driven by a mainspring and train
of wheels N and 0) revolves until the other pin in the snail or cani C is oaught by
the end of the lever G, by this revolution of the snail or cam C the levers D E F
are raised sufficiently to allow the cams A and B to revolve without touching the
rollers on the levers D and E. It will be observed in the drawings that the
lever F lias a roller running on the edge of the snail or cam C for the purpose
of raising the levers D E and F which lovers may either be made in one piece or
Joined together.
The
Fig. 2 represents the position of the various parts when the chronograph 18
going. When the ratchet wheel carrying the disc J is moved forward another
tooth the lever H is raised by its roller coming out of a notch in the disc J.
roller Q on the end of the lever II is thus brought into contact with the cam on
the balance staff. The roller pressing on the said cam holds the balance in a
position from which it will start i cadily when wanted. This cam and roller are
shown in au enlarged scale in Fig. 5.
Fig. 3 shows the position of the levers when the chronograph is stopped. When the
ratchet wheel and disc are moved another tooth the lever G springs into the
position shewn in Fig. 1. allowing the snail or cam C to move into the position
shewn in Fig. 1 the roller on lever F falls from the highest part of the snail or
cam C. The rollers or levers D and E come into contact with the cams A and B
and move them into the position shown in Fig. 1 the hands being carried by those
cams are thus brought to zero.
.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what
we claim is
1. In chronographs the actuating of the levers which set the hands to zero by
means of a snail or cam driven by a mainspring and train of wheels as herein ahewn
and described.
2. The stopping and starting the balance by means of the cam and roller.
3. The arrangement and combination of parts and operation of the same
forming our improved chronograph.
Dated this Sixth day of Feb 1806
JAMES MCNEIL.
THOS. MONTGOMERY.