Improvements in and relating to Sighting Apparatus for Guns.
Year: 1893

page_text: Date of Application, 12th May, 1893
Complete Specification Left 8th Feb. 1894 Accented 31st Mar
1804
PROVISIONAL SPECIFICATION.
Improvements in and relating to Sighting Apparatus for Guns.
We, FREDERICK SAMUELSON, Engineer, and PHILIP THAINE, Secretary, both
of Victoria Mansions, 32 Victoria Street, in the City of Westminster, do hereby
declare the nature of this invention to be as follows:-
This invention relates to sighting apparatus for guns.
The chief feature of our invention relates to the mode of mounting and adjusting
the fore and rear sights. These sights are carried by a common sight-bar which is
adapted to turn about the same axis as the gun or cradle for vertical elevation. By
this construction the vertically movable rear sight-bar heretofore usually employed
is dispensed with.
Another feature of our invention is the simple provision made to allow for drift
of the projectile.
Our invention also comprises other improvements in detail hereinafter
referred to.
In carrying our invention into effect as applied for example to a gun that turns
on trunnions, we provide a sight-bar of suitable length, having a fore-sight at one
end thereof, and a rear sight at or near the other end thereof, said rear sight being
fitted as is usual with a transverse screw for adjusting the sight laterally to allow
for deflection.
The said sight-bar is mounted with a capability of turning on a pivot formed
on the trunnion or on a piece secured to the trunnion, the said pivot being
co-axial with the trunnion. The trunnion or trunnion-piece is formed with
a screw segment with which gears a worm mounted upon a shaft supported
in bearings provided in the sight-bar. Said shaft is prevented from end-
wise movement in its bearings by collars or shoulders formed or fixed thereon. At
the rear end of the said shaft is fixed a hand wheel by which the shaft may be
rotated. Upon so rotating the shaft the worm is caused to travel around the
toothed segments before mentioned and in so doing carries the sight-bar with it,
thus causing said bar to rotate about its pivot.
Recording mechanism is provided to indicate either the inclination of the sights,
that is to say, the angle through which they have been turned relatively to the axis
of the gun, or the range, or both inclination and range. One convenient construc-
tion adapted for this purpose comprises an interually toothed ring which gears with
a pinion on the shaft before mentioned, and is turned by the rotation of said shaft
simultaneously with the turning of the sight-bar about its pivot. Said ring is
graduated on its face, a portion of which is exposed through an opening in the
cover or case which encloses the ring. Suitable reading marks or points are
provided whereby the position of the ring, that is to say, the inclination or range as
the case may be, can be read at a glance, and the sight-bar can be turned to bring
any desired inclination or range, within the limits of the instrument, opposite the
reading point. This done, the gun is then elevated or depressed until the line of
sight is on the object aimed at.
To provide for the inaccuracy of aim due to the drift of the projectile which is
different for different ranges or elevations, the pivot pin about which the sight-bar
turns instead of being truly axial with the trunnions of the gun may be slightly
inclined thereto in the proper direction so that the apparent path of the sights as
seen from the rear instead of being vertical is inclined or elliptical, deviating more
and more from the vertical as the elevation increases.

page_text: It is obvious that our improved sighting arrangement can be applied to guns
which have no trunnions, it being merely necessary to arrange the sight bar so that
it turns about the same axis as the gun.
We may vary the construction of our sighting arrangement in detail without
departing from the nature of our invention.
Dated this 12th day of May 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in and relating to Sighting Apparatus for Guns.
We, FREDERICK SAMUELSON, Engineer, and PHILIP THAINE, Secretary, both
of Victoria Mansions, 32 Victoria Street, in the City of Westminster, 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 sighting apparatus for guns.
The fore and rear sights are carried by a sight-bar which is mounted with a
capability of turning on a part fixed to the gun or cradle. The axis about which
the sight-bar turns is the same as that about which the gun turns for elevation, or
is parallel or very slightly inclined thereto.
Our invention relates chiefly to the mode of adjusting the sight-bar. It also
relates to very simple means for ensuring a suitable allowance for drift of the
projectile.
Referring to the accompanying drawings,
Figure 1 is a side elevation partly in section of a sighting device constructed
according to our invention.
Figure 2 is a plan, and
Figure 3 is a rear elevation of the same, and
Figure 4 is a section taken on the line a, a Figure 1.
Like letters of reference denote corresponding parts in all the figures.
A is the sight-bar, of suitable length, having a fore sight B at one end
thereof, and a rear sight C at or near the other end thereof, said rear sight being
fitted, as usual, with a transverse screw C¹ for adjusting the sight laterally for
deflection.
The sight bar A is furnished with a boss A and is mounted with a capability of
turning on a pivot D formed on a piece E' secured to the trunnion E of the gun,
or some other suitable part of the gun or cradle. The pivot D may be co-axial
with the trunnion, but in the construction shown, it is slightly inclined to the axis
for a purpose hereinafter specified. The line y, y indicates the axis about which
the gun turns, and 2, z indicates the axis of the pivot D. The line z, z is slightly
inclined to the line y, y. The trunnion-piece E' is formed with a screw segment F
with which gears a worm G mounted upon a shaft G¹ which is supported in
bearings G provided in the sight-bar A. The said shaft G' is prevented by the
worm G from end wise movement in its bearings. On the rear end of the said
shaft is fixed a worm wheel G with which engages a worm G4 secured on a
cross spindle G³. G is a milled hand wheel by which the spindle G³, and
thereby the shaft G', may be rotated. By rotating the said shaft the worm G is
caused to travel around the aforesaid stationary toothed segment F and in so doing
it carries the sight-bar A with it, thus causing the said bar to turn about its
pivot D.
The wheel G preferably has a graduated rim and is arranged to work under a
fixed pointer G7, by which means the number of degrees or fraction of a degree

page_text: through which the sight-bar is turned about its pivot can be accurately observed.
With the gear shown in the drawing, one complete turn of the wheel G³ causes the
sight-bar to turn through an angle of 2°.
Reading or indicating mechanism is provided to show either the inclination of
the sights, that is to say, the angle through which the line of sights has been
turned relatively to the axis of the gun, or the range, or both inclination and
range.
For example a graduated disc H secured to or forming part of the worm
wheel G³ is provided to turn behind the cover plate J. J is an opening in
said cover plate through which the graduations on the disc H can be read.
A reading mark is furnished by a fine wire J² stretched across the opening J'.
The disc H may have two graduated circles, one showing inclination and the other
range.
In lieu of the gear above described for turning the shaft G, we sometimes
provide for turning it directly by a hand wheel on the rear end thereof, but this
construction is not so accurate and is less convenient than that above described, the
hand wheel being at the end instead of at the side. When we provide such gear
we form the reading circle on an annular internally toothed ring which gears
with a pinion on the shaft G₁ and is turned by the rotation of said shaft
simultaneously with the turning of the sight-bar about its pivot. A portion of
said annular ring is exposed through an opening in the cover or case which
encloses the ring.
In either construction, the device is so arranged that the position of the
reading circle, that is to say, the inclination or range as the case may be can be
read at a glance, and the sight-bar can be turned to bring any desired inclination
or range, within the limits of the instrument, opposite the reading point. This
done, the gun is then elevated or depressed until the line of sight is on the object
aimed at.
The above construction of sight-bar is very convenient inasmuch as no long
reading bars are required as is the case in sighting devices heretofore made.
To allow for the lateral deviation or drift of the projectile which is different for
different ranges or elevations, the pivot pin D about which the sight-bar turns
instead of being truly in line or parallel with the axis about which the gun turns for
elevation is as herein before stated slightly inclined thereto in such a direction that
the apparent path of the sights when the bar is turned about its axis as seen from
the rear looking in a direction parallel with the axis of the gun, instead of being
vertical is inclined or elliptical, deviating more and more from the vertical as the
elevation increases.
By this means any depression of the line of sight with respect to the axis of the
gun causes a lateral deviation thereof, such deviation increasing with the depression
of the line of sight.
After the sights have been adjusted to the range or elevation required the gun
is laid to bring the object aimed at in the line of sight; in such movement the
sights travel with the gun and move in a vertical plane or in a plane perpendicular
to the trunnions; that is to say, the lateral deviation of the line of sight remains
undisturbed.
The movement of the bar A is limited by a pin K which is screwed into the
trunnion, and a curved groove or slot K' formed in the inside of the boss A¹, into
which slot the end of the pin K projects. The said pin is inserted and removed
through a hole K' formed in the boss A¹.
It is obvious that our improved sighting apparatus can be applied to guns
which have no trunnions, it being merely necessary to arrange the sight-bar so that
it turns about the same axis as the gun, or about an axis parallel or nearly parallel
thereto.
We may vary the construction of our sighting apparatus in respect of the details
herein described within certain limits without departing from the essential features
of our invention.

page_text: Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. A sighting device wherein the fore and rear sights are carried by a sight-bar
adjustable about an axle secured to one of the trunnions upon which the gun turns
for elevation, the adjustment being effected by worm or equivalent gear which
operates through a wheel or segment concentric with said axle, substantially as
described, for the purpose specified.
2. In such a sighting device, the reading mechanism geared to the shaft G',
substantially as, and for the purpose, specified.
3. A sighting apparatus wherein the rear and fore sights are mounted on a
pivoted bar which is movable independently of the gun, and which automatically
effects the correction for drift.
4. In a sighting device wherein the rear and fore sights are mounted on a pivoted
bar, the axis of said bar so inclined or tilted that when the sighting-bar is turned,
the sighting points viewed from the rear appear to describe an elliptic or a straight
inclined path, for the purpose specified.
5. A sighting apparatus wherein the rear and fore sights are mounted on a
pivoted bar in combination with adjusting and reading mechanism, and constructed
and operating substantially as described with reference to the accompanying
drawings, for the purpose specified.
6. The combination with a gun of a sighting apparatus constructed substantially
as described with reference to the accompanying drawings.
Dated this 8th dox of Kahuna
1004
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.