AN IMPROVED ALARUM NIGHT CLOCK, OR TIME INDICATOR
Year: 1854

page_text: LETTERS PATENT to Sanders Trotman, of Portman Square, in the County
of Middlesex, Hydraulic Engineer, for the Invention of "AN IMPROVED
ALARUM NIGHT CLOCK, OR TIME INDICATOR."
Sealed the 19th May 1854, and dated the 9th March 1854.
COMPLETE SPECIFICATION filed by the said Sanders Trotman at the Office
of the Commissioners of Patents, with his Petition and Declaration, on the
9th March 1854, pursuant to the 9th section of the Patent Law Amend-
ment Act 1852.
I, SANDERS TROTMAN, of Portman Square, in the County of Middlesex,
Hydraulic Engineer, do hereby declare the nature of the said Invention for
"AN IMPROVED ALARUM NIGHT CLOCK OR TIME INDICATOR" to be as follows
(that is to say):
My said Invention, which has reference to the combination of a clock or
watch movement with an illuminator or night light for illumining the dial
so as to make visible the time indicated with or without the addition of an
alarum for giving a signal at any required time, consists in the construction of
an instrument in which a horizontal stand of any convenient form or size is
fitted to a vase or receptacle containing a night light, and also to a pillar sup-
porting a clock or watch movement, to which an alarum disc, if required, and
a revolving hour disc, furnished with figures and with a fixed index for marking
the time, are connected. If the night clock is furnished with an alarum,
suitable perforations are made in the revolving hour disc, to show the alarum
dial through it. The illuminator is also so situated as to yield the greatest

page_text: amount of light to the numeral indicating the time. The advantages to be
derived from my said inprovements consist, firstly, in the great distinctness
with which the time will be indicated by the revolving dial, on which a strong
light is constantly thrown at the precise point passing under the index, which
advantage will be evident from a comparison with the common illuminated
clocks, in which a faint, light, being evenly diffused over a semi-transparent
dial, hardly serves to render visible the fine surfaces of the hour and minute
hands, while many other modifications of such illuminating clocks have been
also attempted at various times without any very satisfactory results. (The
same purpose is obtained more thoroughly by the substitution of the Arabic
numerals for the Roman, some of them being occasionally combined in a
peculiar manner, as shown in the Drawings). Secondly, in the convenience and
portability with which a night-light and clock are constructed and combined
with or without the addition of the alarum, as may be convenient.
But in order that this my said Invention may be more fully understood and
readily carried into effect, I proceed to describe. it by the aid of the accompany-
ing Drawings, reference being had to the letters and figures thereon marked,
that is to say:-
Fig. 1 represents a front elevation of my improved illuminated night-clock;
Fig. 2, a side elevation; Fig. 3, a top or plan view; Fig. 4, a back elevation
thereof; and Figs. 5, 6, 7, & 8 different portions of the various movements
separately shown. In each Figure the same letters of reference denote similar
corresponding parts. A, A, stand; B, B, pedestal for supporting the works;
C, C, cylindrical case enclosing the movement; D, D, dial or hour disc furnished
with the Arabic numerals and combinations previously referred to, and mounted
upon bearings, with which it revolves; E, E, milled-edged thumb disc, moving
concentrically upon a square shank or spindle in connection with the alarum
hand or index E', E', as in manner shown; F, F, alarum dial, situated imme-
diately at the back of the hour disc, in such manner that the figures thereon
may be readily seen through the several openings or perforations G,. G, on the
face of the hour disc; H, H, hour index or hand, fixed or secured to the case
of the instrument in a vertical position over the face of the hour disc, for the
purpose of indicating the time; I, I, key plate or winder, moving concentrically
with the cylindrical case, for the purpose of winding up the spring and giving
motion to the works; K, K, spindle, terminating with a square shank, so as to
receive the thumb disc aforesaid and revolve with it; L, L, elastic washer, for the
purpose of giving the hour dial & alarum dial the requisite friction, so as to
enable both to revolve together by the action of the clock movement; M, M,
small thumb screw, tapped or fitted to the spindle or shank K, for the purpose

page_text: of securing the dials together, and admitting of the outer one being removed,
when desirable, for repairing or otherwise; N, N, night light or illuminator;
0, 0, glass or receptacle for holding the same. In order to set the alarum to
any time required, the alarum hand or index, which is constructed to. revolve
simultaneously with the thumb disc, merely requires to be turned round till it
points to the figure desired; during this movement the hour dial must be held
or retained to prevent its turning round with the thumb screw, with which it
is connected, through the medium of the washer, that the said thumb screw
may be moved, when it is desired, independantly or separately.
Having now fully described the nature of this my said Invention, and the
manner in which the same is to be performed, I would have it clearly under-
stood that I do not by any means confine myself to the precise details herein-
before described and set forth, as the same might be varied without departing
from the general principle of my said improvements; but that which I do claim
as new and of my said Invention is,―
The combination of a night-light with a dial-illuminated thereby in front, in
place of a transparent or semi-transparent dial having a night-light behind it
in night clocks or time indicators, with or without alarums, in the manner and
for the purposes herein-before set forth and described.
In witness whereof, I, the said Sanders Trotman, have hereunto set my
hand and seal, this Eighth day of March, in the year of our Lord
One thousand eight hundred and fifty-four.
SANDERS TROTMAN. (L.S.)