Year: 1886

page_text: Date of Application, 19th Apr., 1836.
. Complete Left, 19th Jan., 1887.
Complete Accepted, 25th Feb., 1887.
[Communicated from abroad by JOHN DUNCAN COLQUnous, of the Village of Wales,
WILLIAM HENRY SCOTT, of Cobourg, and CHARLES SHUTTLEWORTH ELLIS, of
Toronto, all in the Province of Ontario, Canada, Watchmakers.]
I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex
Engineer, do hereby declare the nature of this invention to be as follows:-
:-
The object of the invention is to adapt the dial of a watch or clock for the twenty-
four hour system without changing the numerals from the positions they occupy in the
twelve-hour system and it consists, essentially, of a dial having twelve openings at
the points usually occupied by the numerals, and placing behind the dial a dial-ring
having printed on its surface two sets of figures, one set indicating from one to twelve,
the other set from thirteen to twenty-four, the distances between the figures of each
respective set being the same, so that when the dial-ring is adjusted to expose the
figures from one to twelve through the openings in the dial, the figures indicating
from thirteen to twenty four are hidden from view, and likewise when the dial-ring is
adjusted so as to expose the figures from thirteen to twenty-four through the openings
in the dial the other set of figures are hidden, simple mechanism being provided by
which the change is automatically effected every twelve hours.
W. P. THOMPSON & BOULT, ·
Agents.

page_text: A communication from JOHN DUNCAN COLQUHOUN, of the Village of Wales,
WILLIAM HENRY SCOTT, of Cobourg, and CHARLES SHUTTLEWORTH ELLIS, of
Toronto, all in the Province of Ontario, Canada, Watch-Makers.
I, ALFRED JULIUS BOULT of 828 High Holborn in the County of Middlesex,
M.L.M.E. 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 :-
The object of the invention is to adapt the dial of a watch or clock for the twenty
four hour system without changing the numerals from the position they occupy in the
twelve hour system; and it consists essentially of a dial having twelve openings at the
points usually occupied by the numerals, and placing behind the dial a dial ring having
printed on its surface iwo sets of figures one set indicating from one to twelve the
other set from thirteen to twenty four the distances between the figures of each
respective set being the same so that when the dial ring is adjusted to expose the
figures from one to twelve through the openings in the dial the figures indicating
from thirteen to twenty four are hidden from view and likewise when the dial
ring is adjusted so as to expose the figures from thirteen to twenty four through
the openings in the dial the other set of figures are hidden simple mechanism
being provided by which the change is automatically effected every twelve hours
substantially as hereinafter more particularly explained.
Figures 1 and 2 are enlarged views showing the mechanism by which the figures on
the watch case are automatically changed,
Figure 3 is a view of the dial on a smaller scale than Figures 1 and 2 showing the
twelve openings.
Figure 4 is a cross section through the dial and dial plate.
In introducing the twenty four hour system the main difficulty arises from the fact
that we are all accustomed to the location of the figures on the dial-that to say we
know that six is opposite to twelve and that three is opposite to nine and that if the
minute hand is at three-it means a quarter past the hour indicated by the hour hand
and so on consequently a dial with twenty four figures on its face so entirely changes
the aspect of the dial that a mental calculation is necessary every time the watch or
clock is consulted. It is to avoid this unnecessary labour and to so adapt the figures
that their familiar places will not be altered that this invention is designed.
A represents a dial having twelve openings a at equal distances apart.
B is a ring having two sets of figures printed on its surface as indicated and at such
distances apart that when the ring B is placed behind the dial A and adjusted so as to
expose the figure 1" through one of the openings a all the other figures from one to
twelve are exposed through the said openings and when the ring B is adjusted so as
::

page_text: to bring the figure "18" to the point formerly occupied by "1" all the openings
expose the other figures from thirteen to twenty four while the figures from one
to twelve are hidden. I will thus be seen that by providing mechanism to be
worked from the works of the watch so as to make the change described automatic
every twelve hours we secure a dial adapted for the twenty four hour system without
changing the familiar location of the figures used in the twelve hour system.
While I do not wish to confine myself to the exact mechanism shown to accomplish
the object of this invention I think that the mechanism shown is about the best and
simplest that can be adapted for the purpose and for that reason have chosen it from
others to show how simply the figures may be automatically changed without in any
way interfering with the correct working of the watch movement.
are two blocks screwed onto the dial plate D of the watch movement.
EF are two dogs pivoted respectively to the block C. The outer ends of these dogs
extend into the elongated notch made in the dial ring B. Their inner ends are held
against the eccentric cam G by the springs H. The eccentric cam G is attached to
and placed upon the centre of the toothed wheel I. There are twenty four teeth in
this wheel I. A tooth or pin d is placed on the canon pinion J and the toothed
wheel is located so near to the canon pinion J that at each revolution of the said
canon pinion the pin d engages with the teeth of the wheel I and moves it on its
centre a distance of one tooth and as the eccentric cam G is connected to the wheel I it
is likewise caused to revolve the distance mentioned.
Owing to the peculiar shape of the cam G the dogs E and F are caused to move the
ring B in the following manner.
In order to better explain the construction and operation of the invention I show
the ring B in Figures and 2 in its two positions-that is to say in Figure 1 the dog E
has just moved the ring B so as to expose the figures from one to twelve through the
openings a while in Figure 2 the ring B is shown in the position that it will be moved
to by the dog so as to expose through the openings a the figures ranging from
thirteen to twenty-four. Now in order to understand this movement we will follow
the movement of the cam G from its position shown in Figure 1. In this figure it
will be seen that the tail of the dog E has just reached and fallen over the high end of
the cam G its spring I having pushed it over into the position in which it is indicated
and in doing so moved the dial ring B into the position it is shown in. Previous io
the tail of the dog reaching the point stated the ring B would be in the position
indicated in Figure 2.
As the cam & continues to revolve in the direction indicated by arrow the plain
portion of the cam G comes in contact with the tail of the dog E and the teeth formed
on the opposite side of the cam engage with the tail of the dog F. This action of the
cam on the dog E holds its end against the end of the notch bas indicated in Figure 1.
until its tail has almost reached the commencement of the teeth e; the shape of the
cam & being such that the dog E is pushed over against its spring H carrying its end
away from the notch so that by the time that the tail of the dog has reached the
end of the teeth e the end of the dog E is clear of the end of the notch so as not to
interfere with the free movement of the dial ring B which is brought over into the
position indicated in Figure 2 by the power of the spring H the moment that the
fail of the dog has fallen over the high end of the cam G This operation is
repeated the cam & being constantly revolving in the direction indicated by arrows
and the dogs E and E are alternately brought into action to effect changes regularly
every twelve hours-that is to say for instance the minute hand is set on the canon
pinion so that when it indicates half past twelve the dog F is caused by its spring as
described to adjust the dial ring B so as to substitute for the figures indicating from
one to twelve, the figures indicating from thirteen to twenty four immediately after
which the hands would indicate twenty nine minutes to thirteen and will then
regularly refer to the figures thirteen to twenty four until half past twenty four is
reached when the dog E acted upon by its spring brings the ring B into the position
indicated in Figure exposing through the openings a, the figures indicating from one
to twelve, when the hands will then indicate twenty nine minutes to one although a

page_text: moment before they indicated half past twenty four thus only one set of figures at a
time is exposed and the location of the exposed figures are always the same.
Of course the hands may be adjusted so that the change will take place at other
periods but the foregoing explanation will be sufficient to explain the object and
operation of this invention.
Instead of making the openings a in the dial A. and adjusting the dial ring B by the
mechanism of the watch as described the same effect of course could be secured by
placing the dial A in the position of the ring B and the ring B into the position of the
dial A in which case the openings a would be made in the dial ring B and the dial A
would be actuated by the mechanism described so that in referring to the openings a in
the claim I wish to embrace the substitution suggested.
The tooth e in the eccentric cam Genable the particular dog or F which at the
time be engaged with them to hold the cam G or toothed wheel I stationary when not
acted upon by the pin d and in order to prevent the dial ring B from accidentally
shifting I provide a spring K.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed I declare that what I claim is —
1. A dial ring having two sets of figures one set indicating from one to twelve the
other set from thirteen to twenty four in combination with a dial having twelve
openings made in it substantially as and for the purpose specified.
2. A dial having twelve openings and placed over a dial ring having two sets of
figures marked on its face one set indicating from one to twelve, the other set from
thirteen to twenty four in combination with mechanism operated by the works of the
watch and arranged to adjust the dial ring so as to alternately expose through the
openings in the dial the two sets of figures substantially as and for the purpose
specified.
3. A dial ring B having two sets of figures marked on its surface as specified and
an elongated notch made in its edge the pivoted dogs E and F extending into the
said notch and provided each with a spring H as specified in combination with the
eccentric cam G deriving motion from the works of the watch substantially as and for
the purpose specified.
4. A dial ring B having two sets of figures marked on its surface as specified and
an elongated notch made in its edge the pivoted dogs E and F extending into the
said notch and provided-cach with a spring Has specified in combination with the
eccentric cam G connected to the toothed wheel I which derives motion from the pin d
connected to the canon pinion J substantially as and for purpose specified.