An Improvement in Sights for Small Arms.
Year: 1895

page_text: Date of Application, 18th Mar., 1895
Complete Specification Left, 9th Dec., 1895-Accepted, 29th Feb., 1896
PROVISIONAL SPECIFICATION.
An Improvement in Sights for Small Arms.
THOMAS HECTOR SMITH of No. 3 Cursitor Street Chancery Lane E.C.
Doctor of Medicine do hereby declare the nature of this invention to be as
follows:-
The nature of this invention is to enable the firer of any small arm provided
with these sights, to locate instantly the danger zone in which the objects (say men
singly or in masses) are and without moving the small arm from the aiming
position, the back sight is instantly adjusted by mechanical means. The shooter
without moving either hand from the grasp of the small arm i.e. the left from the
retention grasp, or the right from finger on trigger position (or if left handed
vice versa) is enabled to find & fix the danger zone of object aimed at, on looking
through front sight. These sights are specially adapted for the new small calibre
military rifle with smokeless powder; as there is nothing in the invention that
unfits it for the rough usages of warfare.
The front sight is a perforation in the block of foresight, and the optical
principle is applied, by which objects at various distances, have different dimensions.
These distances, or danger zones, are indicated by daylight horizontal lines, cut in
the platinum perforated foresight.
The backsight, is so arranged, that it starts from the point blank of the weapon.
A connecting, swivelled, small steel bar, is hinged to it, (the backsight), and passes
on the right side, of arm, out of sight, underneath the wood, and steel work of the
rifle, to a circular, ratchet, spring-disk, which is countersunk, and freely movable
and under control of the right thumb, (backwards, or forwards) by means of a
small projecting steel-knob attached to the countersunk spring-ratchet disk.
The backsight, is thus freely movable, up, or down, at advancing, or retreating
objects. When the pressure of the thumb is removed, it, (the backsight) is firmly
held by the spring-ratchet disk, at any angle. Thus, the backsight (ordinary
military) can be fixed at any angle of the quadrant, and is freely, and instan-
taneously, lowered or raised, by simple pressure of the disengaged thumb of the
right hand; said thumb, being in its usual, normal position, when the small arm is
held to the right shoulder in the act of firing, or "present" position, vide" Musketry
Instruction Lee-Metford 1894."
12th Anil 1905
T. H. SMITH, M.D..
An Improvement in Sights for Small Arms.
I, THOMAS HECTOR SMITH 3, Cursitor Street, Chancery Lane, E.C. Doctor
of Medicine, 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 :-
"
The object of the present invention is to enable the user of any small arm first
to locate the particular "danger zone in which the object aimed at is situated,
and secondly to enable him to instantly and automatically adjust the back sight
Price 8d l

page_text: to the correct or corresponding elevation without removing his gaze from the
object or his grasp from the firing position.
This object attain by the employment of the peculiar construction and
arrangement of fore and back sights hereinafter described.
"
I will now by a simple illustration clearly define the term "danger zone."
Let us imagine a man to be standing upright just beyond point blank range and
let such an elevation be given to the weapon pointed at him that the bullet will
just graze the top of his head. The intervening space between the spot on which
the man stands and the point where the bullet will first strike the earth I term a
danger zone," since the elevation of the weapon remaining unaltered the man if
standing anywhere in the line of fire between these two points must obviously be
hit somewhere. Where one danger zone terminates another danger zone commences
and so on until the extreme limit of the range of the weapon is reached, each
danger zone requiring a different elevation to be given to the small arm. The
correct elevation for any particular zone I term the “corresponding elevation ” for
that zone.
It is clear that the spaces which constitute danger zones will vary in length and
number according to the trajectory of the arm used and the height of the object
aimed at, though with regard to the latter the height of an average man standing
upright would in all cases be taken as the standard. Before applying my invention
to a small arm the situation of the danger zones must first be determined by
experiment with the said arm, this having been done I am enabled to apply to the
arm a foresight so constructed and arranged as to indicate to the marksman on
sighting the object the particular danger zone in which the said object is
situated.
The construction and arrangement of the said foresight is based upon the well
known optical law that according to the distance of an object so its apparent size
varies, and the said foresight consists of a frame, preferably of rectangular shape,
the aperture bounded thereby being crossed by a series of thin horizontal wires
having spaces between them the width and number of these spaces depending upon
the length and number of the danger zones, previously ascertained by experiment
as above mentioned.
The object aimed at being sighted through the said aperture so that its base
appears to rest upon the lower boundary thereof, the marksman can at once locate
the danger zone of the object by noting in which of the spaces between the wires
the top of the object appears to terminate since each wire starting from the bottom
of the eight indicates, when the object is sighted, the limit of a danger zone.
first wire from the bottom indicates the limit of the farthest zone at the extreme
The
range of the arm, the second wire indicates the limit of the next nearer danger
zone and so on.
The marksman having previously made experimental trials
ascertained the corresponding elevations, to be given to his weapon, for the various
or otherwise
danger zones he can by my invention, having located the particular danger zone of
the object as above set forth, at once automatically and without removing his gaze
from the object or his grasp from the firing position adjust the backsight to the
corresponding elevation required by the means hereinafter fully described, all
guess work being eliminated and the operation rendered purely mechanical. The
foresight should be so adjusted that when any part of the object aimed at appears
above the upper edge thereof the object will be in point blank range.
I will now describe my invention and the manner of performing the same
having reference to the accompanying drawings in which similar letters refer to
corresponding parts in all the figures.
Fig. 1 is a front elevation, Fig. 2 is a top edge view, and Fig. 3 is a back
elevation of the mechanism for automatically adjusting the backsight.
Fig. 4 is a part sectional side elevation shewing the backsight in position upon
a small arm and the connection between the former and the adjusting mechanism
illustrated in Figs. 1, 2, and 3.

page_text: Fig. 5 is a detached face view of the back sight.
Fig. 6 shews in side elevation the foresight in position upon the barre!.
Fig. 7 is an end view of Fig. 6 and
Fig. 8 is a detached plan view of the foresight.
a is a thin metal plate for carrying the adjusting mechanism of the backsight
and is suitably secured as by the screws a 4 within a groove formed for its reception
in the stock of the gun. Towards the rear end this plate is widened by a semi-
circular projection a 1. bis a disc disposed upon one side of the plate a and the
said semicircular projection and p is a pinion wheel disposed upon the other side
thereof, the said disc and pinion wheel being both mounted on the axis which
passes through the plate a. c is a projecting knob on the face of the disc b the
stem of the said knob passing through a slot in the plate a concentric with
the axis Q and entering and being rivetted to the pinion wheel p. Upon partially
rotating the disc by means of the knob c the pinion wheel p will be caused to
revolve simultaneously. is a rod sliding longitudinally in the guides jk on
plate a the rear end of this rod being cut with teeth so as to form a rack with
which the teeth of pinion wheel p engage, whilst to the front end of the rod s
there is pivotally connected at the link . d1 (Figs. 4 and 5) is a curved lever
arm the upper end d2 of which is bent at right angles and secured by the
screws d3 across the lower ends of the upright arms a 2 of the backsight. The
lower end of this lever arm d 1 is pivotally connected with the before mentioned
link a.
D is a cover plate which slides freely in suitable guides fg formed at
the front end of plate a and is formed with a notch D³ through which the lever
arm dl passes. The object of this plate D' is to prevent dust and dirt from
entering the action.
The entire mechanism is to be so disposed and arranged upon the rifle that the
knob c may be readily operated by the forefinger without removing the hand from
the firing position. In Figs. 6, 7 and 8 g is the frame of the foresight the aperture
bounded thereby being crossed by the thin horizontal wires j. R is the muzzle of
the gun. is a thin platinum wire let into the centre of the upper boundary of
the foresight whereby the object sighted is centred.
In using my invention the marksman will first note the particular danger zone in
which the object is located by sighting the latter through the foresight aperture as
before explained and he will then by moving the knob c with his forefinger rotate
the pinion wheel p and through the slide rods, link and lever arm 1, adjust the
backsight to the corresponding elevation for that zone. The attainment of the
correct position of the backsight is aurally conveyed to the marksman by the following
arrangement :-
ee are a series of pins arranged concentrically around the periphery of the disc b
and d is a flexible spring projecting from the knob e said spring engaging with the
pins e and slipping from one pin to another with a clicking sound when the disc b
is rotated. The object of these pins and engaging spring is twofold, viz., first they
serve to retain the disc in the position to which it has been set and secondly the
clicking of the spring on the pins when the disc is rotated gives aural indication to
the marksman of the distance through which the disc has been revolved. The
marksman having ascertained by experiment the number of clicks emitted when
setting the backsight to the various " 'corresponding elevations" can without
removing his gaze from the object adjust the backsight with absolute certainty to
the corresponding elevation for the danger zone indicated by the foresight, by
counting the clicks.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A foresight for small arms having an aperture therein through which the.
object is sighted said aperture being crossed by horizontally disposed wires sub-
stantially as and from sha

page_text: 2. In combination with a foresight constructed and arranged as set forth in the
preceding claim, a backsight having automatic adjusting mechanism substantially
as described.
3. In combination with the backsight of a small arm, means substantially as
described whereby the former may be automatically adjusted to the required
elevation without removing the eye from the object or the grasp from the firing
position, substantially as specified and illustrated.
Dated this 9th day of December 1895.
E. P. ALEXANDER & SON,
Chartered Patent Agents,
19, Southampton Buildings, Chancery Lane, London, W.C., Agents.