A NEW AND USEFUL IMPROVEMENT IN STOP-WATCHES
Year: 1880

page_text: LETTERS PATENT to Lorentz Albert Groth, Civil Engineer, and Proprietor
of the Scandinavian Patent Office, under the Firm of L. A. Groth & Co.,
97, Finsbury Pavement, London, E.C., for an Invention of "A NEW AND
USEFUL IMPROVEMENT IN STOP-WATCHES." A communication by Henry
Alfred Lugrin and Prosper Nordman, both of New York City, United
States of America.
PROVISIONAL SPECIFICATION left by the said Lorentz Albert Groth at the
Office of the Commissioners of Patents on the 6th August 1880.
LORENTZ ALBERT GROTH, Civil Engineer, and Proprietor of the Scandinavian
Patent Office, under the Firm of L. A. Groth & Co., 97, Finsbury Pavement,
London, E.C. "A NEW AND USEFUL IMPROVEMENT IN STOP-WATCHES." A com-
munication by Henry Alfred Lugrin and Prosper Nordman, both of New York
City, United States of America.
This Invention relates to improved constructions of stop-watches or chronographs,
which are used for timing races and for similar purposes, and the Invention consits
firstly, of a stop-watch, in which the timing attachment is thrown in and out of
gear with the watch movement by two toothed wheels and an intermediate
transmitting double-beveled pinion. One of the toothed wheels is applied to the
arbor of the fourth wheel, while the second toothed wheel is applied to a hollow
tubular arbor that passes through the hollow arbor of the minute hand, and carries
at its opposite end the quarter second-hand. The arbor of the split quarter second-
hand passes through the hollow arbor of the quarter second hand, which latter is
provided with a lifting lever and spring to throw its toothed wheel in or out of
gear with the transmitting double-beveled pinion. The arbor of the minute-hand
is provided with a stop-disk, and with a sleeve shaped arbor, which carries a split
minute hand. A spring-pressed leverarm bears on a stop-disk of the split minute-
hand whenever the quarter second-hand is started. The split-minute-hand as well
as the split quarter second hand is carried back to the minute and quarter second-
hands respectively by the usual shifting spring, both quarter second hands being
returned finally to the starting point by a return-lever and cam.
The Invention consits, secondly, of a transmitting gear-wheel, which is placed

page_text: loosely on the arbor of the third wheel of the watch-movement, and provided with
a clutch device, by which it can be locked to or released from the arbor of the third
wheel. The clutch-device is applied to or removed by a suitable lever and spring-
arm, the spring arm being raised or lowered by a beveled portion of the lever,
which engages a fixed stud on the spring-arm.
5
The toothed wheel which is keyed to the arbor of the second hand, and which is
made either straight or beveled, or in the nature of a crown-wheel, meshes by a small
intermediate double beveled pinion with a second gear-wheel, which is keyed to a
hollow arbor, that passes through the hollow arbor of the minute hand and to the
other side of the movement, and carries at its opposite end the quarter second hand, 1
which moves along a suitably graduated auxiliary dial that encircles the face-dial
of the watch. The split quarter second hand is arranged on the same side of the
movement, its arbor being passed through the hollow arbor of the quarter second-
hand. The quarter second hand is set into motion by throwing the toothed wheel
into gear with the intermediate double-beveled pinion, which is accomplished by
the withdrawing of the beveled lever from a lifting spring, and the action of a
spring interposed between the toothed wheel and frame of the movement.
By throwing the lever under the spring, the spring lifts the hollow arbor and
gear wheel, so that the connection with the double-beveled pinion is interrupted,
and the motion of the quarter second-hand stopped.
The split quarter second hand is stopped in the customary manner in stop
watches by a friction disk and lever at the top of the movement, and sent after
Both hands are then
the quarter second-hand by the usual spring and cam.
returned jointly to the starting point by the usual return-lever and heart shaped
cam on the arbor of the quarter second hand employed in stop watches.
The arbor of the minute hand carries a disk to which the split minute-hand is
connected by a sleeve. The split minute-hand works in connection with the
quarter second hand as follows:-
When the quarter second hand is set in motion, the return lever is carried away
from the heart shaped cam, and pushing against a lever arm throws a lever arm at
the opposite end of its shaft against the disk of the split minute-hand, so as to
stop it. The minute hand then goes on, while the split minute hand is stopped.
When the return lever at the end of the observation falls back to its first position
on its cam, the lever arm releases the disk, which by means of its spring sends the
split minute hand into line with the minute hand, and returns simultaneously
therewith the quarter-second and split quarter-second-hands to the starting-point.
The construction described is to be used whenever a perfect record of the time of
one or more horses at a race is desired, and is more especially designed for more
extended observations.
The following is a stop watch or chronograph, which is intended to obtain the
same result in a simpler manner. The split quarter second and split minute hands
are dispensed with, and simply a quarter-second hand arranged, which is started or
stopped by throwing an intermediate mechanism into or out of gear with the
watch-movement.
In this construction the transmitting gear-wheel receives its motion from the
third wheel of the watch-movement whenever it is thrown into gear therewith.
For this purpose the gear-wheel is placed loosely on the arbor of the third wheel,
and connected thereto or released therefrom by a clutch-device, which consits of a
loosely-sliding conical sleeve and of a spring-arm. The gear-wheel rests loosely on
a disk of the arbor, and is tightly locked to the disc and arbor by the joint action
of the sleeve and spring-arm, the gear wheel being beveled around its central
opening to correspond to the conical shape of the sleeve. The upper part of the
arbor above the disk is made square, as well as the hole in the conical sleeve, so
that the latter is compelled to turn with the arbor. The spring arm is forked or
recessed at its free end, so as to extend beyond the square portion of the arbor, and
bear on the conical sleeve at both sides of the same.
The opposite side of the spring arm is permanently attached to the supporting

page_text: bridge-plate of the movement. A fulcrumed lever engages by a beveled portion a
fixed screw stud of the spring-arm, and bears simultaneously by its outer end-
portion on a friction-disk on the arbor of the timing quarter second hand. This
timing hand is returned by the usual heart-cam and shifting-lever to its starting
point on the dial.
When the timing quarter second hand is at rest, the lever engages by its beveled
projection the fixed stud, and holds thereby the spring arm in raised position clear
of the clutch-sleeve, so that the transmitting wheel rests loosely on the supporting
disk without following the motion of the arbor. Simultaneously therewith the
friction disk of the shifting heartcam is held by the pressure of the outer end of the
lever, and thereby the quarter second-hand retained in position at the starting
point.
Whenever it is desired to throw the timing device into operation, the lever is
carried back by pressing on its outer end, so that it clears the stud of the spring-
arm, and the friction disk of the heart-cam at the same time. The free end of
the spring-arm forces then the conical sleeve down, so that the latter locks the
transmitting gear wheel to the arbor of the third wheel. The timing mechanism
is thereby thrown into gear with the watch movement, and set in motion by the
intermeshing of the transmitting gear wheel with the pinion and arbor of the
timing hand. The band may be instantly stopped by carrying the lever forward
again, by which motion the spring arm is raised, and the clutch sleeve released
from the transmitting wheel. The timing hand is at the same time arrested by
the pressure of the lever on the friction disk. The hand is finally returned to
the starting point by the shifting lever and cam. The clutch mechanism can also
be arranged to be worked by the ordinary push device.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Lorentz Albert Groth in the Great Seal Patent Office on the 5th February
1881.
LORENTZ ALBERT GROTH; Civil Engineer, and Proprietor of the Scandinavian
Patent Office, under the Firm of L. A. Groth & Co., 97, Finsbury Pavement,
A com-
London, E.C. "A NEW AND USEFUL IMPROVEMENT IN STOP-WATCHES."
munication from abroad by Henry Alfred Lugrin and Prosper Nordman, both of
New York City, United States of America.
This Invention relates to improved constructions of stop watches or chronographs,
which are used for timing races and for similar purposes, and the Invention consists,
firstly, of a stop watch in which the timing attachment is thrown in and out of
gear with the watch movement by two toothed wheels and an intermediate
transmitting double bevelled pinion. One of the toothed wheels is applied to the
arbor of the fourth wheel, while the second toothed wheel is applied to a hollow
tubular arbor that passes through the hollow arbor of the minute hand, and carries
at its opposite end the quarter second hand. The arbor of the split quarter second
hand passes through the hollow arbor of the quarter second hand, which latter is
provided with a lifting lever and spring to throw its toothed wheel in or out of gear
with the transmitting double bevelled pinion. The arbor of the minute hand is
provided with a stop disk and with a sleeve shaped arbor, which carries a split
minute hand. A spring pressed lever arm bears on a stop disc of the split minuto
hand whenever the quarter second hand is started. The split minute hand, as well
as the split quarter second hand, is carried back to the minute and quarter second
hand respectively by the usual shifting spring, both quarter second hands being
The Invention
returned finally to the starting point by a return lever and cam.
consists, secondly, of a transmitting gear wheel, which is placed loosely on the
arbor of the third wheel of the watch movement, and provided with a clutch device by
which it can be locked to or released from the arbor of the third wheel. The clutch
device is applied to or removed by a suitable lever and spring arm, the spring arm
being raised or lowered by a beveled portion of the lever which engages a fixed stud
on the spring arm. In the accompanying Drawings, which fully illustrate the Inven-
tion, Fig. 1 represents a face view of the improved stop watch drawn on an enlarged
scale; Fig. 2 is a vertical central section of the same; Figs. 3 & 4 are detail side views
shewing different forms of the motion transmitting gear wheels and their inter-
mediate double beveled pinion; Figs. 5 & 6 are respectively a bottom view and
a top view of the movement, shewing the mechanism for stopping the split minute
hand; Fig. 7 is a top view of a stop watch on an enlarged scale with a portion of
the bridge plate broken away; and Fig. 8 is a vertical transverse section of the
latter construction on line x, x, Fig. 7. Similar letters of reference indicate
corresponding parts.
Referring to the Drawing, A represents a toothed wheel, which is keyed to the
arbor of the second hand, and which is made either straight or beveled or in the
nature of a crown wheel, as shewn respectively in Figs. 4, 2, and 3. The toothed
wheel meshes by a small intermediate double beveled pinion B, with a second gear
wheel A which is keyed to a hollow arbor C, that passes through the hollow arbor
of the minute hand and to the other side of the movement, and carries at its
opposite end the quarter second hand D, which moves along a strictly graduated
auxiliary dial that encircles the face dial of the watch. The split quarter second
hand D is arranged on the same side of the movement, its arbor D2 being passed
through the hollow arbor of the quarter second hand. The quarter second hand D
is set into motion by throwing the toothed wheel A¹ into gear with the intermediate
double beveled pinion B, which is accomplished by the withdrawing of the

page_text: beveled lever a from a lifting spring b, and the action of a spring & interposed
between the toothed wheel and frame of the movement. By throwing the lever a
under the spring b the spring b lifts the hollow arbor C and gear wheel A¹, so that
the connection with the double beveled pinion is interrupted and the motion of the
quarter second hand stopped. The split quarter second hand is stopped in the
customary manner in stop watches by a friction disk e and lever fat the top of the
movement, and sent after the quarter second hand by the usual spring and cam.
Both hands D and D' are then returned jointly to the starting point by the usual
return lever g and heart shaped cam g' on the arbor of the quarter second hand
employed in stop watches. The arbor of the minute hand E carries a disk h, to
which the split minute hand E' is connected by a sleeve. The split ininute hand
works in connection with the quarter second hand as follows:-When the quarter
second hand is set in motion the return lever g is carried away from the heart shaped
cam, and pushing against a lever arm g³ throws a lever arm g³ at the opposite end
of its shaft against the disk h of the split minute hand so as to stop it.
The minute hand then goes on, while the split minute hand is stopped. When
the return lever g at the end of the observations falls back to its first position on
its cam the lever arm g³ releases the disk h, which, by means of its spring, sends the
split minute hand into line with the minute hand and returns simultaneously
therewith the quarter second hand and split quarter second hand to the starting
point.
The construction described is to be used whenever a perfect record of the time of
one or more horses at a race is desired, and is more especially designed for more
extended observations. In Figs. 7 & 8 a stop watch or chronograph is shewn,
which is intended to obtain the same result in a simpler manner. The split quarter
second and split minute hands are dispensed with, and simply a quarter second hand
arranged, which is started or stopped by throwing an intermediate mechanism into
or out of gear with the watch movement.
In this construction the transmitting gear wheel G receives its motion from the
third wheel of the watch movement whenever it is thrown into gear therewith.
For this purpose the gear wheel G is placed loosely on the arbor G¹ of the third
wheel, and connected thereto or released therefrom by a clutch device H which
consists of a loosely sliding conical sleeve i and of a spring arm i'.
The gear-wheel G rests loosely on a disk 2 of the arbor G', and is tightly locked
to the disk and arbor by the joint action of the sleeve and spring arm, the gear
wheel G being beveled around its central opening to correspond to the conical
shape of the sleeve. The upper part of the arbor G above the disk is made square,
as well as the hole in the conical sleeve, so that the latter is compelled to turn with
the arbor. The spring arm is forked or recessed at its free end so as to extend
beyond the square portion of the arbour, and bear on the conical sleeve at both sides
of the same.
The opposite side of the spring arm is permanently attached to the supporting
bridge plate of the movement. A fulcrummed lever Z engages by a beveled
portion a fixed screw stud 12 of the spring arm 2, and bears simultaneously by
its outer end portion on a friction disk m on the arbor of the timing quarter second
hand. This timing hand is returned by the usual heart cam and shifting lever to
its starting point on the dial. When the timing quarter second hand is at rest the
lever engages by its beveled projection the fixed stud, and holds thereby the spring
arm in raised position clear of the clutch sleeve i, so that the transmitting wheel G
rests loosely on the supporting disk 2 without following the motion of the arbor.
Simultaneously therewith the friction disk of the shifting heart cam is held by the
pressure of the outer end of the lever l, and thereby the quarter second hand
retained in position at the starting point. Whenever it is desired to throw the
timing device into operation the lever is carried back by pressing on its outer end,
so that it clears the stud of the spring arm and the friction disk of the heart cam
at the same time. The free end of the spring arm forces then the conical sleeve
down, so that the latter locks the transmitting gear wheel to the arbor of the third

page_text: wheel. The timing mechanism is thereby thrown into gear with the watch move-
ment and set in motion by the intermeshing of the transmitting gear wheel with
the pinion and arbor of the timing hand.
The hand may be instantly stopped by carrying the lever forward again, by
which motion the spring arm is raised and the clutch sleeve released from the
transmitting wheel. The timing hand is at the same time arrested by the pressure
of the lever on the friction disk. The hand is finally returned to the starting point
by the shifting lever and cam. The clutch mechanism can also be arranged to be
worked by the ordinary pushed device.
Having thus described the nature of the said Invention, I claim,-
First. In a stop watch the combination of a toothed wheel on the arbor of the
second hand, and of an intermediate double beveled transmitting pinion with a
toothed wheel on the arbor of the quarter second hand, and with lever and spring
devices for throwing the toothed wheel of the quarter second hand in or out of gear
with the transmitting pinion, as set forth.
Second. In a stop watch, the combination of the hollow arbor of the quarter
second hand passing through the hollow arbor of the minute hand, and being
connected thereto at the top of the movement with transmitting gearing and
mechanism for throwing the hollow arbor in or out of gear therewith, as herein set
forth.
Third. In a stop watch, the combination of the hollow arbor of the minute hand
carrying a disk and split minute hand with a stop lever and shifting mechanism
working jointly with the shifting mechanism of the quarter second band,
substantially as set forth.
Fourth. In stop watches, the combination of arbor G¹ of the third wheel, the said
arbor having a fixed disk and square portion above the disk, and of the
transmitting wheel G, with a conical clutch-sleeve i having a square hole for the
arbor, and with a binding spring arm i, substantially as herein specified.
Fifth. In stop watches, the combination of the arbor G¹, of the third wheel
having a disk, transmitting wheel G, conical clutch sleeve i, and spring arm i¹,
having fixed screw stud 12, with a lever having beveled projecting portion 1¹,
all as herein described.
Sixth. In stop watches, the combination of the transmitting mechanism G, G¹,
clutch device H, and friction disk m of the arbor of the timing hand, with a lever l
that is adapted to apply or release the clutch device from the transmitting wheel,
simultaneously with binding on or releasing the friction-disk of the time hand,
substantially as herein and for the purpose set forth.
In witness whereof, I, the said Lorentz Albert Groth, have hereunto set my
hand and scal, this Fourth day of February, in the year of our Lord One
thousand eight hundred and eighty one.