An Improved Means for Facilitating the Reading of Gun-sight and other Scales.
Year: 1896

page_text: Date of Application, 10th Feb., 1896
Complete Specification Left, 10th Dec., 1896-Accepted, 6th Feb., 1897
ISIONAL
An Improved Means for Facilitating the Reading of Gun-sight and
other Scales.
1, LEONARD PERCIVAL ASBURY 17 New Walk Terrace York, Mechanical
Draughtsman, do hereby declare the uature of this invention to be as follows:-
An arrangement by means of which fine scales and divisions may be read with
much greater facility and clearness, both by day and night.
In Figs. 1 and 3, the arrangement is shewn adapted for reading the figures and
divisions on an ordinary gun sight bar.
On the sight bar socket is a hollow light-tight cylinder A. into which, at the
proper ascertained distance, is fixed a lens or a combination of lenses B, preşunably
of the portrait type. Around this lens or lenses B. is placed an electric lamp C.
preferably of the form shewn at Fig. 2. This lamp is mounted in a suitable shield
which throws the light of the lamp to one side only of the lens or lenses. At the
other side of the lens or lenses at a fixed focal distance is a screen of ground glass
or similar substance D. suitably mounted and fixed into front end of cylinder A.
On the outside of cylinder is fitted a length of tube or hood E. which is made to
slide on the turned surface of the cylinder, and is drawn out as shewn in Fig. 1.
when the instrument is being used in daylight, and may be slid back or taken off
altogether when the instrument is required for use at night or in dark places.
The figures and divisions on the sliding sight bar are engraved (reversed) on the
face F. preferably in black on a white dead ground, and are illuminated by the
lamp, and by means of the lens or lenses their image is thrown onto the ground
glass screen, magnified, Fig. 3. On the ground glass screen one or more lines,
arrow heads, or a central point may be marked for convenience in reading.
Suitable provision is made for changing or renewing the lamp (which may be
fixed into shield by cement or any convenient method) and making good the
electrical connections.
Deted this the 8th dar of February 1896
LEO. P. ASBURY.
COMPLETE SPECIFICATION.
An Improved Means for Facilitating the Reading of Gun-sight and
other Scales.
I, LEONARD PERCIVAL ASBURY, of 17 New Walk Terrace, York, in the
County of York, Engineer, 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 :-
This invention relates to improved. means for facilitating the reading of finely
divided scales by night or day, and is especially applicable for facilitating the
reading of the scales on sight bars for guns.

page_text: The said invention comprises a. screen, a lens by which a magnified image of the
scale is formed on the screen, and means for illuminating the scale.
Referring to the drawings accompanying my Provisional Specification which
illustrate the invention as applied to a sight bar for guns,
Figure 1, is a vertical central section of the sight bar socket and reading
apparatus.
Figure 2 is a view of the illuminating lamp detached, and
Figure 3 is a rear elevation of the sight bar socket and reading apparatus.
The sight bar socket is constructed with an extension or box A in which is fitted
a lens or combination of lenses B and a ground glass or other suitable screen D
upon which is projected a magnified image of the divisions of the scale formed on
the face of the sight bar F. The box A is made impervious to light and the lens
or lenses B and screen D are arranged at the proper distances from the sight bar
to secure a sharply defined image of the scale on the screen.
Within the box A is a lamp C, preferably an electric glow lamp, having an
annular shape as indicated in Figure 2 and arranged to surround the lens B. The
said lamp is covered on one side by a cement or other shield so that its light
is thrown in one direction only, viz. towards the scale. The lamp may be readily
removed and replaced by another lamp and the connections made good when
required. E is a hood mounted with a capability of sliding on the box A.
The said hood (which may have a full opening as shewn or a reduced opening at
the front end) is drawn out as indicated when the instrument is being used in
daylight, and is slid back or removed when the instrument is being used at night
or in dark places.
The figures and divisions of the scale on the face of the sight bar F are preferably
engraved in black lines ou a dead white ground. The figures on the scale should
be inverted so that their image on the screen may be upright, unless an erecting
lens is used in which case the figures need not be inverted.
The screen D may be marked with an arrow head or one or more lines or
a central point for convenience in reading.
It is obvious that the apparatus comprising the leus, the lamp and the screen
arranged substantially as described may be similarly applied to the reading of other
scales than those of gun sights.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is :-
1. The apparatus comprising a lens, a lamp, and a screen arranged substantially
as described by which a magnified image of a scale may be obtained for the
purposes specified.
2. A gun sight furnished with apparatus constructed substantially as described
with reference to the accompanying drawings for the purposes specified.
Dated this 9th dive
000
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.