IMPROVEMENTS RELATING TO THE SIGHTING OF FIRE ARMS to be as follows:- of fire-arms.
Year: 1885

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents,
Southampton Buildings, in the County of Middlesex do hereby declare the nature
of my invention for "IMPROVEMENTS RELATING TO THE SIGHTING OF FIRE ARMS
to be as follows:-
This invention relates to the sighting of fire-arms.
"
It frequently happens in the sighting of a fire-arm that the axis of the barrel, or
the line of fire which is the continuation thereof, is not in the same vertical plane
as the line of sight determined by the breech-sight and by the front or muzzle
sight. The consequence of this want of coincidence is that the line of fire deviates
laterally from the line of sight so that a lateral deviation of the projectile also
ensues.
The object of my invention is to provide means for enabling the marksman to
ascertain whether the lines of sight and fire are in the same vertical plane, and if
not, to adjust the gun to the required position before firing.
The plane determined by the two lines of sight and fire is only the longitudinal
vertical plane dividing the gun into two symmetrical portions and hereinafter
termed the plane of symmetry. It is consequently only necessary in order to
fulfil the object of this invention, to ensure the perfect verticalness of this plane
of symmetry. This is accomplished in the following manner; that is to say ;-
A level of any suitable construction is applied to the fire-arm, for instance a spirit-
level, which level is arranged in a plane perpendicular to the line of sight, in such
a manner that its two extremities, located one on one side and the other on the
other side of the plane of symmetry of the fire-arm, shall be at equal distances
from any point of the axis of the gun. It is thus obvious that when the axis of
the level is horizontal, the line of sight and the line of fire will be situated in the
same vertical plane; In the case of the spirit level it will consequently be sufficient
to ensure that the air bubble is centred when the gun is to be fired in order to
avoid the lateral deviation of the projectile, supposing, of course, that the appli-
cation of the level to the fire-arm has been made with the necessary precision.

page_text: In order to facilitate the operation of verifying that the fire arm is in the
proper position when the sighting is effected, recourse can be had to many different
arrangements.
According to one arrangement especially adapted for ordnance, the breech of the
gun is provided with a recess designed to receive the level.
In portable fire arms it is preferable to apply the level to the upper extremity
of the scale of the breech-sight. This can be effected either when use is made of
a scale consisting of a graduated plate raised perpendicularly to the gun, and
provided with a slide which carries the sighting slot or groove or when use is
made of a circular or dial scale consisting of a plate having at its free end a
sighting slot or groove and turning upon a hinge between two lugs which are
graduated for distance.
In the latter case the level is inserted in a tubular cavity formed in the metal
of an enlargement with which the upper extremity of the plate is provided.
When the fire-arm is in position for firing, the bottom of the sighting groove
must coincide with the air-bubble. If during the pointing the bubble recedes from
its central position, notches permit the direction of the deviation to be recognized.
According to another arrangement the sighting groove is cut in a projection
coinciding with the centre of the bubble. When the bubble is centred, it dis-
appears from the eye of the marksman it being only perceptible in one or the other
of two notches when it is necessary to bring the gun to the proper position before
firing.
100K

page_text: I, WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake & Co, Patent Agents,
Southampton Buildings in the County of Middlesex, do hereby declare the nature
of the invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement :—
This invention relates to the sighting of fire-arms and comprises the improve-
ments hereinafter described which are applicable to military rifles and similar
fire-arms and also to ordnance.
In the use of military rifles and similar fire-arms provided with back-sights as
ordinarily constructed, the marksman is liable, in sighting the arm, to hold the
same in such a position that the axis of the barrel, and the line of fire (which is
theoretically a continuation thereof) are not in the same vertical plane as the line
of sight determined by the back and front sights.
When the arm is thus held, the line of fire is displaced laterally, at the rear end
of the fire arm, relatively to the line of sight; therefore although the correct
elevation of the arm may be ensured by accurate sighting, yet, by reason of this
lateral displacement of the line of fire, the projectile will not follow its intended
course and will consequently be more or less wide of its mark.
The object of the present invention is to obviate this defect and to provide for
enabling the marksman to readily adjust the gun so that the line of sight and the
line of fire are in the same vertical plane.
In most military rifles, the plane passing through the two lines of sight and of
fire divides the arm into two symmetrical portions; for convenience of description,
this plane is hereinafter termed the plane of symmetry.
To fulfil the object of the said invention, it is only necessary to provide for
ensuring that this plane of symmetry shall be truly vertical, while the gun is being
pointed and fired. For this purpose, I combine, with the back-sight, a level of any
suitable description, preferably a spirit-level, in such a manner that the marksman,
while aiming or pointing the gun, can very readily determine the position of its
plane of symmetry, and adjust the same as required.
The said invention will be more readily understood by reference to the accom-
panying drawing, in which
Figure 1 is a diagram illustrating the lateral displacement of the line of fire
relatively to the line of sight when the plane of symmetry of a fire-arm is not
vertical.
Figure 2 is a side elevation, partly in vertical section, of a back-sight with the
present improvements applied thereto, showing the sight raised.
Figure 3 is a rear elevation of the said back-sight, showing the same attached
to a gun-barrel.

page_text: Figure 4 is a rear elevation of the vertically sliding piece of the said back-sight,
a portion of the same being removed.
Figure 5 is a rear elevation, and
Figure 6 a plan of part of another back-sight, showing a modification of the
said invention.
Figure 7 is a section on the line a, a, Figure 5.
Figure 8 is a rear elevation, and
Figure 9 a plan of part of another back-sight, showing a further modification of
the said invention.
Figure 10 is a section on the line a¹, a¹, Figure 8.
Figure 11 is a rear elevation, and
Figure 12 a side elevation of part of a leaf-sight with the present improvements
applied thereto.
Like letters of reference indicate corresponding parts throughout the drawing.
In the diagram Figure 1, a is the back-sight, b the front-sight and c the point
aimed at. This diagram is intended to illustrate the effect produced when a gun
is incorrectly held with respect to the position of the line of fire relatively to the
line of sight. It will be seen that, although the sighting of the gun is correct,
the line of fire, which is indicated by the dotted line d, e, is not in the same vertical
plane as the line of sight, consequently the projectile will strike the point d instead
of the point c. But, by this invention, the marksman is enabled to avoid such
inaccuracy in aiming and firing a gun.
In Figures 2, 3 and 4, f is the pivotted bar of the back-sight and g is the
vertically sliding piece thereof. h is a spirit level, which is arranged within a
recess or cavity in the sliding piece g at right angles to the line of sight, and in
such a manner that the centre of the said level is in the plane of symmetry of the
fire-arm, and its extremities are equidistant from any given point in the axis
of the barrel. It is, therefore, obvious that, when the fire-arm is so held that
the axis of the said level is horizontal, the line of sight and the line of fire
will be situated in the same vertical plane. Consequently, if the level has been
applied to the fire-arm with the necessary precision, the correct aiming of the gun
will be ensured by holding the same in such a manner that the air-bubble is in the
centre of the level, and, therefore, in the same vertical plane as the notch of the
sight, as shown in Figure 3.
In Figure 4, the sliding piece is shown with its back plate g¹ removed to show
more clearly the position of the level h.
To permit the air-bubble in the level to be seen by the marksman, while aiming
the gun, whatever may be the position of the sliding piece g upon the pivotted
bar f, I form apertures g' in the said sliding piece g, through which the air-bubble
can be clearly seen when the said bar is vertical.
In the modifications of this invention shown in Figures 5 to 7, and in Figures 8
to 10, I form other apertures 9 in the sliding piece g, through which the air-
bubble can be clearly seen when the pivotted bar fis horizontal or slightly inclined,
as when firing at short ranges. When the sight is constructed in this manner,
whatever may be the range for which the sight is adjusted, the said air-bubble is
plainly visible. Moreover, by reason of its being immediately beneath the
line of sight, the marksman can, with great facility, accurately adjust the line of
fire laterally relatively to the line of sight, at the same time that he adjusts the
gun to obtain the required elevation.
The sliding piece shown in Figures 5, 6 and 7 is graduated and provided with
an adjustable slide i for making allowance for deviation of the projectile by
the wind.
Figures 11 and 12 show part of a leaf-sight, that is to say, a back-sight which
consists of a bar or plate f designed to be pivotted at one end between two lugs
which are graduated for different ranges, and having a sighting groove or notch f¹
formed in its free end.

page_text: The level is inserted in recesses or cavities formed in lugs or enlargements f¹
at the upper or free end of the bar f.
When the fire-arm is in the correct position for firing, the bottom of the sighting
groove must coincide with the air-bubble.
In some pieces of ordnance, the line of sight is outside the vertical plane passing
through the line of fire. But, in this case, the plane of symmetry of the gun must
be perfectly vertical when the sighting is effected, therefore these improvements
can with advantage be applied to such pieces of ordnance.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondent I declare that what I claim is :-
First The combination, with the back-sight of a fire-arm, of a spirit or other
level, for the purpose hereinbefore described.
Second-The combination, with the vertically sliding piece of a back-sight, of a
spirit or other level arranged within the same in such a manner that its air-bubble
is visible through apertures therein, substantially as described with reference to
Figures 2, 3 and 4, or to Figures 5, 6 and 7, or to Figures 8, 9 and 10 of the
drawing for the purpose specified.
Third The modification of the said invention substantially as described with
reference to Figures 11 and 12 of the drawing.
HASELTINE, LAKE & Co.,
Agents for the Applicant.