Improvements in the Method of and Means for Sighting Rifled Fire-arms.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Method of and Means for Sighting Rifled
Fire-arms.
I, JOHN FORMBY, of Formby Hall, Formby, Lancs., Gentleman, do hereby
declare the nature of this invention to be as follows:-
This invention relates to the method of and means for sighting rifled firearms
and has for its object to provide rapid and reliable means for sighting, whereby
the greatest facility is afforded for picking up a fresh aim with great rapidity
and for maintaining the aim upon any rapidly moving object, such, for example,
as a small body of troups, especially when advancing. towards or retiring from
the gun.
One advantage of this invention is that mechanical adjustment is not necessary
(as with the sliding leaf on ordinary sights) to take up or alter either range or
sighting, but all measurements, even the most minute, can be accurately made
by eyo, which is an important simplification and effects in practice a great saving
of time.
Though principally designed for fire-arms using small-arm ammunition, my
invention is applicable to artillery which can be pointed by hand, and is laid
rather by sight than by scale.
The principle or method herein newly applied is that of forming and using
equal divisions of the backsight, for elevation, in shortening its scale, and in
marking the foresight or foresights in exact subdivisions of those on the back-
sight, both for elevation and line.
The improvements consist in marking the scale of the backsight horizontally,
in equal and suitable divisions throughout, and vertically in suitable divisions,
such divisions being either equal or multiples of each other. The said divisions
are made preferably by cross wires or the like fixed across the open frame of the
structure and such horizontal and vertical distances are not necessarily of equal
widths. The nominal scale of hundreds of yards is plainly marked on the front
side or sides of the backsight as a rough eye-guide to the user, preferably by
notches as well as by figures. The foresight (which may be of Calliper pattern)
is horizontally and vertically marked in exact subdivisions of the horizontal
and vertical divisions of the backsight above referred to, and the V notches may
be repeated also on its lower side.
In machine guns especially, which should be sighted accurately to extreme
ranges, in order to get full range without an inconvenient height of backsight, I
may employ two similar foresights carried in one frame of which the vertical
distance apart should be equal to the length of scale of the backsight, so that
the sight from the top of the backsight and the uppermost foresight should give
the same range as that from. the bottom of the backsight and the lowermost
foresight, thus obtaining a practically continuous scale on changing the fore-
sight. The foresights are carried in rings mounted in the said frame and such
rings may be in the form of short tubes carrying the sights centrally. For

page_text: higher elevation the lower tube may be slightly inclined. The distance between
the level of the lowest sight and that of the upper part of the gun barrel will
vary with the construction of guns.
The frames of both the foresight or foresights and the backsight are preferably
hinged flaps which can be shut down when not in use, and may be so made and
arranged us to be truly vertical at a given point, preferably at half the maximum
elevation of the sighting (that is, when the foresight is changed) as a correction
for angular displacement, which otherwise causes both loss of elevation and
diminution of the apparent distances between the horizontal divisions.
Dated this Fifth day of July 1899
Improvements in the Method of and Means for Sighting Rifled
.
Fire-arms.
I, JOHN FORMBY, of Formby Hall, Formby, Lancs., Gentleman, 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 the method of and means for sighting rifled firearms
and has for its object to provide rapid and reliable means for sighting: whereby
the greatest facility is afforded for picking up a fresh aim with great rapidity
and for maintaining the aim upon any rapidly moving object, such, for example,
as a small body of troops especially when advancing towards or retiring from
the gun.
:
One advantage of this invention is that mechanical adjustment is not necessary
(as with the sliding leaf on ordinary sights) to take up or alter either range or
sighting, but all measurements, even the most minute, can be accurately made
by eye, which is an important simplification and effects in practice a great saving
of time.
Though principally designed for fire-arms using small arm ammunition, my
invention is applicable to artillery which can be pointed by hand, and is laid
rather by sight than by scale.
The principle or method which, by my invention, is newly applied, is that of
forming and using equal divisions or spaces of the backsight for elevation in
shortening its scale, and in so constructing the foresight or foresights for use in
conjunction therewith as to allow of exact and minute subdivision of the said
spaces of the backsight, both for elevation and for line.
In fully describing my invention I will refer to the accompanying drawings
in which Fig. 1 is a front elevation and Fig. 1ª a plan of my improved backsight.
Fig. 2 is an elevation and Fig. 2ª a plan of my improved foresight. Fig. 3 is a
diagram showing the back-sight in dotted lines projected upon the foresight in
full lines as when seen by the eye of the user. Fig. 4 is a range table which
may be arranged in suitable position upon the gun. Fig. 5 is an elevation of a
double foresight and Fig. 6 is a diagram illustrating the method of using the
sights and the double foresight for obtaining increased range without using sights
of inconvenient dimensions.
The improvements consist in arranging the scale of the backsight B, Figs. 1
and 1, horizontally in equal' and suitable divisions throughout, and vertically in
suitable divisions, which divisions are made preferably by cross wires or the

page_text: like a a, b b.fixed across the open frame c of the structure, and such horizontal
and vertical distances are not necessarily of equal widths. I prefer to make the
spaces (for line) between the vertical wires bb of the backsight B 50 per cent.
larger than those between the horizontal wires a a thereof as illustrated. I may
state by way of direction that I have found by experience that 15/100ths of an
inch between horizontal wires and 22/100ths. of an inch between vertical wires
to be good proportions for the sight, though of course I do not limit myself to
any specific width. The foresight may be of the Calliper pattern as first proposed
and described in my Provisional Specification but I find that it has certain dis-
advantages and I therefore prefer to use as a foresight an open frame such as F
with diagonal pairs of cross-wires dd, d' d'; forming a lozenge in the centre as
illustrated in Figs. 2 and 3: In this foresight the same principle originally
enunciated is accurately followed, the sight being so constructed that by its uso
the spaces on the backsight B described can be accurately and minutely sub-
divided by the observer both vertically and horizontally, that is to say, both for
elevation and for line and without mechanical aid. The wires d d' are somewhat
thicker than those a b of the backsight B and are stretched diagonally across the
frame F and so spaced to take up apparently slightly less space than the horizontal
wires of the backsight between the top and bottom of the lozenge, when seen as
shown in Fig. 3: it is evident that this spacing will vary according to the relative
distances intended to be kept between the observer's eye and the sights. I prefer
to fix the backsight B about halfway between the eye of the observer and the
foresight F, and the sights to be practically the same distance apart as in an
ordinary rifle or firearm, in which case the diagonal pairs of wires dd of the
foresight may be spaced at the same distance, apart as the horizontal wires a a
of the backsight. A nominal scale of yards for each cross wire a a for both upper
and lower foresights (if two are used as presently explained) is conveniently
arranged upon or in connection with the gun where it can be easily read. I have
shown for example in Fig. 4 such a scale, the tens of yards marked thereon being
calculated on the principle of the ordinary trajectory of the Lee-Metford rifle.
This example is not of course arbitrary. To facilitate counting, small studs
or projections such as ss are fixed outside the frame c opposite the ends of every
third or fourth cross-wire à a, Figs. 1 and 1º.
With this system of cross-wires I may combine an ordinary sliding shallow
V-backsight which in its lowest position in conjunction with the. bead foresight
forms an emergency short range sight, but which, in cases where the cross-wires
are difficult to observe may be slidden up or down the frame and used under
conditions when it is difficult or impossible to define the cross-wires. This
emergency sight consists of a bead foresight such as R, Figs. 2, 3 and 5 mounted
on the sloped shoulders of a solid block 9. The additional backsight consists of
a very broad and shallow V-shaped piece T, the bottom of which is, made flat
for a short breadth at t.. Its arrangement on the backsight is shown in plan in
Fig. 1. These sights are preferably placed at the level of one or more exact
subdivisions of the back-sight below its lowest cross-wire a¹, so that the bead
foresight R can be used with the cross-wires a a if desired. In using my
improved sights I prefer to sight over the top of the lozenge in the foresight,
but its, centre or lower angle may be used, if desired.
In machine guns especially, which should be sighted accurately to extreme
ranges, in order to get full or increased range without necessitating an incon-
venient height of backsight, I may employ two similar foresights as shown
at F F1, Fig. 5, carried in one frame; the vertical distance 7, Fig. 5, apart of
these two sights should be equal to the length of scale of the backsight i.e. the
distance between the top and bottom wire thereof, so that the sight from the top
of the backsight and the uppermost foresight F should give the same range as
that from the bottom of the backsight and the lowermost foresight F; thus I am
able to obtain a practically continuous scale on changing from the lower to the
upper foresight. The distance between the level of the lowest sight. and that
.

page_text: of the upper part of the gun barrel will of course vary with the construction of
guns.
The diagram Fig. 6 is intended to explain the method of using my improved
sights when a double forcsight is employed. The hard line L L represents the
gun when at point blank range, and the hard line L L the line of sight. The
dot and dash lines M M, M M show a change of position to 4° of elevation, and
the dotted lines N N, N¹ Na further change to 8° of elevation (which in this case
is supposed to be the maximum). W represents the centre of motion or trun-
nions. B B B are the several positions of the backsights and F F F of the
foresights respectively at 0° 4° and 8° of elevation; and I prefer to so arrange
these sights as to lie truly vertical at half elevation as a correction for angular
displacement, which otherwise causes both loss of elevation and diminution of
the apparent distance between the horizontal divisions:
The position E represents that of the eye of the observer (at or approximately
at the same distance from the backsight B as the backsight B is from the front-
sight F). I would have it understood that this range of elevation above described
is only given as an example and may be increased or diminished as required.
In all cases I arrange the frames of the sights edgewise to the eye of the observer
for the purpose of better focussing and definition of distant objects also the
sights are hinged and arranged to be folded down when not in use.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The method of sighting rifled fire-arms whereby all measurements can be
made by the eye, in which a back-sight divided into a number of spaces of equal
widths in the horizontal plane and equal widths in the vertical plane (but not
necessarily of equal widths in both planes) is used in conjunction with a foresight
or foresights having open spaces so arranged as to subdivide the spaces in the
said backsight equally and minutely and both horizontally and vertically, i.e.
both for elevation and for line, substantially as herein set forth.
2. The means for sighting rifled fire-arms by the eye alone, comprising a
framed backsight divided by vertical and horizontal wires into spaces such as
above referred to, for use in conjunction with a foresight or foresights consisting
of a frame mounted on the barrel and having wires diagonally stretched therein
in such manner as to divide up the spaces of the backsight, substantially as and
for the purpose herein described.
3. The herein described improved construction of sights for sighting rifled
fire-arms, the parts being arranged and adapted for use substantially in the
manner set forth and illustrated in the drawings.
Dated thin Fifth day of il 1000.
Dated this Fifth day of April 1000.
For the Applicant,
J. C. CHAPMAN &. Co.,
. Chartered Patent Agents, 70, Chancery Lane, London, W.C.