IMPROVEMENTS IN WATCHES
Year: 1868

page_text: LETTERS PATENT to William Ehrhardt, of Birmingham, in the County
of Warwick, Chronometer and Watch Manufacturer, for the
Invention of "IMPROVEMENTS IN WATCHES."
Scaled the 11th June 1869, and dated the 24th December 1868..
PROVISIONAL SPECIFICATION left by the said William Ehrhardt
at the Office of the Commissioners of Patents, with his Petition,.
on the 24th December 1868.
I, WILLIAM EHRHARDT, of Birmingham, in the County of Warwick,
Chronometer and Watch Manufacturer, do hereby declare the nature of.
the said Invention for "IMPROVEMENTS IN WATCHES," to be as follows:-
My Invention relates, firstly, to keyless watches, that is, to watches.
which are wound up by the rotation of an axis passing through the
pendent of the watch.
I arrange the mechanism for winding up the watch by means of the
said axis and also for setting the fingers of the watch. in the following.
manner: The inner end of the said axis carries a bevilled pinion

page_text: which engages with a toothed wheel working in the manner herein-
after described on one of the plates of the watch. The said toothed
wheel engages with a second toothed wheel, and the said second toothed
wheel with a third toothed wheel, all in the same plane. The said third
toothed wheel acts directly on the spring barrel of the watch, and is
provided with a click to prevent its return motion. The axis of the first-
named toothed wheel is not fixed to the said bottom plate, but is
stationed in a slot concentric or nearly concentric with the circumference
of the said bottom plate, and the said axis is capable of a slight motion
in the said slot. A spring bearing against the said axis presses it in
the direction proper to make the first-named toothed wheel engage
with the second-named toothed wheel. By turning the winding axis
in the proper direction the winding up of the watch is effected; when
the winding axis is turned in a direction contrary to that proper to
wind up the watch the pressure of the teeth of the first-named wheel
against those of the second-named wheel causes the axis of the said
first wheel to recede in its slot, and the teeth of the first-named wheel
to escape over the teeth of the second-named wheel without injury to
the winding mechanism. By means of a lever, one end of which
projects from the edge of the watch, pressure can be applied to the axis
of the first-named toothed wheel in a direction contrary to that exerted
by the spring, and by the said pressure the said first-named toothed
wheel can be brought into gear with a train of wheels connected with
the fingers of the watch, and the said fingers may be thus set or adjusted.
When the said lever is no longer pressed the said first-named toothed
wheel is again brought into gear with the winding mechanism by means
of the spring described.
My Invention consists, secondly, of the improvement herein-after
described in the stop work for preventing the overwinding of watches.
In the said mechanism as ordinarily constructed a pin on the arbor of
the spring barrel engages at each rotation of the barrel with one of
the teeth of the stop wheel. As the barrel is turned it advances the
said stop wheel one tooth at each rotation, and at the required time
brings the said stop wheel into such a position as to prevent the; further
rotation of the barrel and the overwinding of the watch.
My improvement consists in making in the arbor of the spring barrel
four or other number of holes more than one at equidistant points, in
either of which holes the pin acting on the stop wheel can be placed.

page_text: By this arrangement the mainspring can be "set-up" with greater
nicety than by the mechanism as ordinarily constructed. This part of
my Invention is applicable to watches generally.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Ehrhardt in the Great Seal Patent Office
on the 17th June 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EHRHARDT, of Birmingham, in the County of Warwick, Chronometer
and Watch Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of December, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Ehrhardt, Her special
licence that I, the said William Ehrhardt, my executors, administrators,
and assigns, or such others as I, the said Willliam Ehrhardt, 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
"IMPROVEMENTS IN WATCHES," upon the condition (amongst others) that
I, the said William Ehrhardt, 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 Inven-
tion, 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 Ehrhardt, 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 thereof, that is to say :-
My Invention relates, firstly, to keyless watches, that is, to watches
which are wound up by the rotation of an axis passing through the
pendent of the watch.

page_text: I arrange the mechanism for winding up the watch by means of the
said axis and also for setting the fingers of the watch in the following
manner-The inner end of the said axis carries a bevilled pinion which
engages with a toothed wheel working in the manner herein-after
described on one of the plates of the watch. The said toothed wheel
engages with a second toothed wheel, and the said second toothed wheel
with a third toothed wheel, all in the same plane. The said third toothed
wheel acts directly on the spring barrel of the watch, and is provided with
a click to prevent its return motion. The axis of the first-named toothed
wheel is not fixed to the said bottom plate, but is stationed in a slot
nearly concentric with the circumference of the said bottom plate, and
the said axis is capable of a slight motion in the said slot. A spring
bearing against the said axis presses it in the direction proper to make
the first-named toothed wheel engage with the second-named toothed
wheel. By turning the winding axis in the proper direction the winding
up of the watch is effected. When the winding axis is turned in a
direction contrary to that proper to wind up the watch the pressure of
the teeth of the first-named wheel against those of the second-named
wheel causes the axis of the said first wheel to recede in its slot, and the
teeth of the first-named wheel to escape our the teeth of second-
named wheel without injury to the winding mechanism. By means of
a lever, one end of which projects from the edge of the watch, pressure
can be applied to the axis of the first-named toothed wheel in a direction
contrary to that exerted by the spring, and by the said pressure the said
first-named toothed wheel can be brought into gear with a train of
wheels connected with the fingers of the watch, and the said fingers may
be thus set or adjusted. When the said lever is no longer pressed the said
first-named toothed wheel is again brought into gear with the winding
mechanism by means of the spring described.
My Invention consists, secondly, of the improvements herein-after
described in the stop work for preventing the overwinding of watches.
In the said mechanism as ordinarily constructed a pin on the arbor of
the spring barrel engages at each rotation of the arbor with one of the
teeth of the stop wheel. As the arbor is turned it advances the said stop
wheel one tooth at each rotation, and at the required time brings the said
stop wheel into such a position as to prevent the further rotation of the
arbor and the overwinding of the watch.
My improvement consists in making in the arbor of the spring barrel

page_text: four or other number of holes more than one at equidistant points, in
each of which holes the pin acting on the stop wheel can be placed.
" with greater
By this arrangement the mainspring can be "set up
nicety than by the mechanism as ordinarily constructed. This part of
my Invention is applicable to watches generally.
Having explained the nature of my Invention I will proceed to
describe, with reference to the accompanying Drawing, the manner in
which the same is to be performed.
Figures 1 and 2 represent front elevations, and Figures 3 and 4 back
elevations of a portion of a keyless watch drawn double the full size, the
mechanism for winding up the said watch and for setting the fingers
being constructed and arranged according to my Invention. In Figures
1 and 3 the parts of the watch are represented in position for winding
the said watch, and in Figures 2 and 4 the parts are represented in
position for setting the fingers of the said watch. The same letters of
reference are employed to indicate the same parts in Figures 1, 2,
3, and 4.
up
a is a bevilled pinion turned by the milled head 6 passing through the
pendent c of the watch, the stem of the said milled head being fitted on
the axis of the said pinion. The said pinion a engages with a toothed
wheel d, the axis of which passes through and is capable of a slight motion
in a slot e in the watch plate f. The wheel d is free to rotate in either
direction. The back end of the axis of the toothed wheel d is prolonged
and carries a head d³, on one side of which the spring g presses. A
lever h, h, turning on the centre ³ is situated at the opposite side of the
head d (see Figures 3 and 4). The toothed wheel a gears with a second-
toothed wheel i, and the toothed wheel i gears with a toothed wheel k, all
in the same plane. The axis of the toothed wheel k is situated on the arbor
of the spring barrel 1 at the back of the watch. A spring pawl m engages
with the toothed wheel k, and prevents the return motion of the wheels
k, i, and spring barrel. The spring g presses the toothed wheel d in
the direction proper to engage its teeth with the teeth of the second
toothed wheel i, as represented in Figures 1 and 3. On the opposite side
of the toothed wheel d is a train of toothed wheels n, p, connected in
the ordinary way with the fingers of the watch. By pressing upon the
projecting end h of the lever h, h², in the direction indicated by the
arrow in Figures 2 and 4, the toothed wheel d may be moved in a
direction contrary to that in which it is pressed by the spring 9, and the

page_text: said toothed wheel be made to gear with the wheel n of the train of
wheels by which the fingers are set, as represented in Figures 2 and 4.
The normal position of the parts of the watch is that represented in
Figures 1 and 3, the toothed wheel & being in gear with the toothed
wheel. By turning the milled head in the direction proper for
winding up the watch the motion of the said milled head is transmitted
through the bevilled pinion a and toothed wheels d, i, and k to the
spring barrel, and the said watch is wound up. When the milled
head is turned in a direction contrary to that proper to wind up the
watch the resistance which is offered by the teeth of the locked wheel i
to the rotation of the wheel a causes the spring g to yield and allow the
said wheel d to recede in the slot e; the teeth of the wheel a therefore
escape over the teeth of the wheel i without injury to the winding-up
mechanism. On removing the pressure from the wheel d the spring g
again presses it into gear with the wheel i, and by turning the milled
head in the proper direction, as before explained, the watch may be
wound up.
When it is wished to set the fingers of the watch the pro-
jecting end h² of the lever h, h³, is pressed in the direction indicated by
the arrow in Figures 2 and 4. The inner end of the lever is thereby
made to act upon the head d' of the axis of the wheel d, and cause
the said wheel to move in its slot e and gear it with the wheel n, as
represented in Figures 2 and 4. By maintaining the pressure on the
lever h, h, and turning the milled head 6 the motion of the said milled
head is transmitted through the pinion a and toothed wheel d to the
train of wheels n, p, and the fingers of the watch may thereby be set
or adjusted. When the pressure is removed from the projecting end h²
of the lever h, 2, the toothed wheel d is again brought into gear with
the toothed whceli by means of the spring g, as represented in Figures
1 and 3, and the parts of the watch are in position for winding up the
said watch.
Figure 5 represents in vertical section, and Figure 6 in plan the stop
work of a watch drawn to a large scale provided with my improvement.
Figure 7 represents in clevation and plan the arbor of the spring barrel
of the same. q is the spring barrel of the ordinary kind; is the arbor
of the spring barrel; & is the stop wheel with which at each rotation of
the arbor for winding up the mainspring a pint on the said arbor
engages, and at the required time brings the said stop wheel into such
a position as to prevent the further rotation of the said arbor and the

page_text: overwinding of the watch. When the watch is going the spring barrel q
revolves round the arbor and reverses the stop wheels. The stopwork
mechanism described is of the ordinary kind.
According to this part of my Invention I make the pin t, which acts
upon the stop wheel 8, removeable, and I make in the arbor > four
holes u, u, ȧt equidistant points, in either of which holes the pin t may
be fixed. I fix the pin t in one or other of the holes u by making a
screw on its lower end which takes into a screw tapped in the said holes.
Instead of four holes a two, three, or more than four holes may be made
in the arbor for the purpose described. By this arrangement the main-
spring in the barrel q can be "set-up" with greater nicety than by the
ordinary mechanism, in which one fixed pin t, the position of which is
unchangeable, is used; that is to say, by my improvement the arbor
can be turned a quarter, half, or other portion of a rotation instead of a
complete rotation, so that by removing the pin t to a hole u above or
below that in which it is fixed the tension of the mainspring may be
reduced or increased at pleasure.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood that
I do not limit myself to the precise details herein described and illus-
trated, as the same may be varied without departing from the nature of
my Invention; but I claim as my Invention,-
Firstly. The improvements, herein-before described and illustrated in
Figures 1, 2, 3, and 4 of the accompanying Drawing, in mechanism for
winding up and setting the fingers of keyless watches, that is to say,
mounting the toothed wheel d (to which motion is transmitted from a
milled head in the pendent of the watch) on an axis capable of moving
in a slot in one of the watch plates, so as to permit the said toothed
wheel to be thrown into and out of gear with either of two trains of
wheels situated respectively on either side the said toothed wheel, one of
the said trains of wheels transmitting motion to the spring barrel for
winding up the watch and the other to the fingers of the watch, the said
arrangement also permitting the rotation of the said wheel d in either
direction without injury to the watch.
Secondly. The improvement, herein-before described and illustrated in
Figures 5, 6, and 7 of the accompanying Drawing, in the stopwork for
preventing the overwinding of watches, that is to say, making at equi-
distant points in the arbor of the spring barrel four or other number of

page_text: holes more than one, in either of which holes a removeable pin on the
arbor which acts on the stop wheel can be placed for the purpose of
"setting-up" with great nicety the mainspring, substantially as described
and illustrated.
In witness whereof, I, the said William Ehrhardt, have hereunto
set my hand and scal, this Fifteenth day of June, in the year
of our Lord One thousand cight hundred and sixty-nine.
Witness,
GEORGE SHAW.
WILLIAM EHRHARDT. (L.S.)