AN IMPROVEMENT IN THE CONSTRUCTION OF ATTACHABLE SECONDS WAI
Year: 1855

page_text: LETTERS PATENT to Edward Daniel Johnson, of Wilmington Square, in
the County of Middlesex, Watch Manufacturer, for the Invention of
"AN IMPROVEMENT IN THE CONSTRUCTION OF ATTACHABLE SECONDS WAI
PROVISIONAL SPECIFICATION left by the said Edward Daniel Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
30th November 1855.
I, EDWARD DANIEL JOHNSON, of Wilmington Square, in the County of Mid-
dlesex, Watch Manufacturer, do hereby declare the nature of the said
Invention for AN IMPROVEMENT IN THE CONSTRUCTION OF ATTACHABLE SECONDS
WATCHES, to be as follows:
This Invention relates to a novel arrangement of mechanism to be applied
to watches for the purpose of putting a centre seconds hand in and out of
action. To this end, I set above the arbor of the centre seconds wheel a loose
spindle, which carries the seconds hand, and rests upon that arbor as in a
step. Keyed to this spindle is also a cross bar, to the opposite ends of which
a crescent spring is rivetted. The extremities of these springs (which have a
tendency to press downwards) are bent round at an angle, and allowed to bear
at certain periods on the chamfered edge of a disc, which is fixed to the centre
seconds arbor. To ensure perfect contact between the springs and disc (when
such is required), the chamfered edge is roughened or milled, and the ends of
the springs are double-pointed to take into the indents. Immediately beneath

page_text: these crescent springs is an annular spring lever, whose office is to keep these
springs out of contact with the disc.
When it is required to give motion to the seconds hand, this spring lever is
depressed by means of a lever, which is acted upon by pushing in a stop that
passes through the watch pendant, and when pressed forwards is caused to
depress the annular spring lever. The crescent springs will then take on to
the milled edge of the disc, which, being on the centre seconds arbor, receives
a continuous rotary motion. As soon as contact is established between the
crescent springs and disc, rotary motion will be communicated to the seconds
hand spindle, and consequently to the hand itself, which motion will be
continued so long as pressure is on the sliding stop of the watch pendant;
but immediately the pressure is removed, the annular spring lever will be free
to rise, and it will then lift the crescent springs out of contact with the rotating
dise, and the motion of the seconds hand will instantly cease. By these means
short intervals and periods of time may be measured with the greatest
exactness, and without the necessity for watching the movement of the seconds
hand.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edward Daniel Johnson in the Great Seal Patent Office on
the 30th May 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
DANIEL JOHNSON, of Wilmington Square, in the County of Middlesex, Watch
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirtieth day of November, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edward Daniel Johnson, Her special license that I, the said Edward
Daniel Johnson, my executors, administrators, and assigns, or such others as I,
the said Edward Daniel Johnson, 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 "AN
IMPROVEMENT IN THE CONSTRUCTION OF ATTACHABLE SECONDS WATCHES," upon the
condition (amongst others) that I, the said Edward Daniel Johnson, by an
instrument in writing under my hand and seal, should particularly describe

page_text: 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 Edward Daniel Johnson, do hereby
declare the nature of my said Invention, and in what manner the same is to
be performed; to be particularly described and ascertained in and by the
following statement, reference being had to the Drawing hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
This Invention relates to a novel arrangement of mechanism to be applied
to watches for the purpose of putting a centre seconds hand in and out of
action; the object being to enable the wearer of the watch to ascertain with
exactness the duration of certain actions, or the intervals of time between'
their repetition, without diverting his attention or even his vision from any
fleeting occurrence. To this end, I connect the centre seconds hand with:
the moving mechanism by friction of contact, which contact is maintained
only so long as the pressure of the wearer's finger is maintained on a spring
stop, and I thus bring the seconds hand completely under the controul of the
wearer.
In the accompanying Drawing, Fig. 1 is a plan view, and Fig. 2 a cross
section, of so much of a watch (on an enlarged scale) fitted with my improve-
ment as will serve to explain its nature and mode of action. a is the seconds
hand, affixed to a loose spindle b, which is set above the arbor of the centre
seconds wheel, and rests upon that arbor as on a step; keyed to this spindle 6 is
also a cross bar c, which carries at its opposite ends one of a pair of crescent
springs d, d; the free extremities of these springs are bent round at an
angle, and present a forked termination to the chamfered edge of a disc e,
which is fixed to and rotates with the centre seconds arbor. A tendency is
given to the springs d, d, to bear down with their forked ends on the disce,
and to ensure instant and continuous contact between the springs and disc
(when such is required); the chamfered edge of the disc is roughened or milled
to receive the forked or double-pointed ends of the springs. Immediately
beneath these crescent springs is an annular spring lever f, whose office is to
press against the under surface of these springs and to keep their free ends
out of contact with the disc e.
When, therefore, it is required to give motion to the seconds hand a, in
order to measure, for example, the speed of a fast train, this spring lever must
be depressed to permit of the seconds hand receiving motion from the disc on
the seconds wheel arbor. The depression of the spring lever fis effected

page_text: by means of an arm g, which has its fulcrum at h, and is jointed to a stop i
that passes though the watch pendant. The extremity of this arm g bears
upon the spring lever f, and it underlies a bracket piece k, affixed to the frame
plate, which bracket piece is wedge-shaped on its under side, to present an
increased thickness to the arm g as it is advanced, and thereby ensure the
depression of the spring lever. It will now be understood that when the stop
i is pressed forward, the arm g will turn on its fulcrum, and depress the annular
spring lever f.
The crescent springs will then be free to take on to the milled edge of the
disc e, which (being on the centre seconds arbor) will impart through the
crescent, springs rotary motion to the seconds hand spindle, and consequently
to the hand itself, which motion will be continued so long as pressure is on
the sliding stop of the watch pendant; but immediately the pressure of the
finger is removed from the stop i, the annular spring lever will.be free to rise,
and it will then lift the crescent springs out of contact with the rotating disc,.
and the motion of the seconds hand will instantly cease; at the same time
a spring;l, which bears against the arm g, will force it and the stop i back to
their, quiescent position. By this means short intervals and periods of time
may be measured with the greatest exactness and without watching the
movements of the seconds, hand, it only being necessary to know, the standing
position of the seconds hand at the time of taking the observation, and for
this purpose it may be convenient to keep it set to a given point, say, for
example, the graduation on the dial marked XII.
Having now set forth the nature of my Invention of "An Improvement in
the Construction of Attachable Seconds Watches," and explained the manner
of carrying the same into effect, I wish it to be understood that under the
above in part recited Letters Patent I claim, the mode of transmitting motion
from the seconds, wheel arbor, to the seconds hand, as above described. -
'In witness whereof, I, the said Edward Daniel Johnson, have hereunto
set my hand and seal, the Thirtieth day of May, in the year of our
Lord One thousand eight hundred and fifty-six.
Witness,
J. W. MOFFATT,
66, Chancery Lane..
E. D. JOHNSON. (L.S.)