MENTS IN ILLUMINATED CLOCKS
Year: 1880

page_text: PROVISIONAL SPECIFICATION left by the said Charles Hugh Leycester at
the Office of the Commissioners of Patents on the 30th December 1880.
CHARLES HUGH LEYCESTER, of Gwynfé, Llangadock, South Wales. IMPROVE-
MENTS IN ILLUMINATED CLOCKS."
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My Invention relates to a construction and arrangement of dials and indices for
clocks, so that when illuminated from within they shall at night shew the time
distinctly at a distance, and during daylight they shall also give a distinct indication*
of the time. For this purpose I make the dial in three parts; the central part is a
disc, which is all opaque, except a glazed radial slit, which may be shaped as a
minute or hour hand; outside the disc is a ring, also opaque, except glazed slits or
openings through it, which are shaped and arranged to shew the successive hour
numbers. Outside this ring there is another ring opaque, except one glazed
opening through it, which is conveniently made of triangular form, presenting its
apex towards the hour ring. The hour ring remaining stationary, while the disc
within it revolves once in an hour, the transparent slit in the disc when illuminated
from within will point as a hand to the minutes, and the exterior ring being made
to revolve once in 12 hours the opening in it will point to the hours. The functions
of the disc and outer ring may be inverted, the slit in the disc being employed as
the hour hand, and the opening in the outer ring acting as the minute band. Or
the outer ring may remain stationary, and both the disc and the numbered.ring
may be made to revolve at suitable speeds, as may be readily understood.
The dial generally may be of a dark colour, the glazing of the slits and openings
being of a light colour, so that during daylight there may be sufficient distinction
to give the required indication. Or the dial generally may be of a light colour,
and dark screens or shutters may be provided behind the slits and openings, so as
to present through them a dark colour for daylight reading, these screens being
withdrawn at night to permit the light to shine through.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Hugh Leycester in the Great Seal Patent Office on the
20th June 1881.
CHARLES HUGH LEYCESTER, of Gwynfé, Llangadock, South Wales.
MENTS IN ILLUMINATED CLOCKS."
"IMPROVE-
My Invention relates to a construction and arrangement of the dials and indices
for clocks, so that when illuminated from within they shall at night shew the time
distinctly at a distance, and during daylight they shall also give distinct indication
of the time. For this purpose I make the dial as I will describe, referring to the
accompanying Drawings. Fig. 1 is a front view, and Fig. 2 a sectional plan.
The dial is made in several separate parts; first, there is a central disc A, which
revolves once an hour, and which has through it a radial slit a that may be shaped
as a minute hand; secondly, there is a fixed ring B, which has openings through
it representing the twelve hours; thirdly, there is a ring C which revolves once in
12 hours, and which has through it an aperture e that may be of triangular shape,
as shewn in Fig. 1; this aperture serves to point to the hour on the stationary
ring B; finally, there is the fixed outer frame D. The revolving disc A, the fixed
ring B, and the revolving ring C may be of metal, with the apertures through them
glazed; or they may be of glass, with all their surfaces obscured, except the parts
-which correspond to the apertures. By selecting strongly contrasted colours for
the opaque and the transparent parts there will be a distinct indication of the hour
and minute by daylight, as indicated at Fig. 3, and at night the interior light
shining through the apertures will give the required indication, as shewn at Fig. 1.
The disc A and ring C may be caused to revolve by any suitable gearing, such as
that represented in Fig. 2, where E is part of the general framing of the clock; F is
a pinion on the spindle of the disc A, driving through an intermediate wheel G, a
wheel H at half the speed of F. On the spindle of the wheel H is a pinion h,
which gears with internal teeth I on the ring C, the radius of those teeth being to
that of the pinion h in the proportion of 6 to 1. When driven by such gearing the
.ring will make one revolution during 12 revolutions of the disc A.
The arrangement of the dial may obviously be inverted, that is to say, the slit a
of the disc A may be made to serve as the hour hand, the aperture c of the ring C
serving to point to minutes, the apertures for which would then be formed in the
part B of the fixed ring, the arrangement of the gearing being altered in a
corresponding manner.
Having thus described the nature of my Invention, and in what manner the
same is to be performed, I claim in respect of dials for clocks internally
illuminated,
First. Distinguishing the hour numbers by the contrast of transparent and opaque
parts of a stationary ring, whilst the pointers or hands are similarly distinguished
respectively on a disc revolving within the stationary hour ring, and on a ring
revolving outside the stationary hour ring, substantially as herein described.
Second. The construction and arrangement of illuminated dial herein described
with reference to the accompanying Drawings.
In witness whereof, I, the said Charles Hugh Leycester, bave hereunto set
my hand and seal, this Eighteenth day of June, in the year of our Lord
One thousand eight hundred and eighty one.