Improvements in Sighting Apparatus for Heavy Guns.
Year: 1896

page_text: Date of Application, 8th Jan., 1896-Accepted, 17th Oct., 1896
COMPLETE SPECIFICATION.
Improvements in Sighting Apparatus for Heavy Guns.
I, AUGUST SCHRIEVER, of No. 64 Gartenstrasse, Düsseldorf, Merchant, 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 consists of a quadrant level which allows the accurate sighting
of the gun at any distance and also makes allowance automatically for the
"deflection of the gun," which is a technical term indicating the deflection of a
rifled shot which increases with the range and trajectory of the projectile.
In order that my invention may be the better understood I now proceed to
describe the same, reference being had to the accompanying drawings and to the
letters and figures marked thereon. Like letters refer to like parts in the various
figures.
Figure 1 is a part sectional side elevation of the quadrant level,
Figure 2 is a plan,
Figure 3 is back elevation, and Figures 4 and 5 are details of the same.
This quadrant level consists of a casing G, which is placed with its lower
plate P on a suitable part of the gun. The casing G has a segmental arm B with
a scale divided into spaces each representing 100 metres, on which slides a clip S
which carries the sight V. A level L is pivotted at one end D and carries at the
other end a slotted quadrant tongue Z to which is connected the clip S by the set
screw K. The sleeve H is guided by means of a pin x in an oblique groove N
of the casing G, whereby the "deflection," i.e. the side deflection of the rifled
projectile corresponding to the difference of distance or height of trajectory is
automatically adjusted.
This quadrant level serves for the sighting of the gun with automatic allowance
for the changing level of the land, in the following manner;
When the gun has been sighted over the back sight and front sight according
to the estimated distance which gives a known angle of trajectory by the usual
sights and the slide S carrying the auxiliary lateral sight V has been adjusted to
suit the trajectory of the distance determined (during which operation the corre-
sponding lateral movement of the sight V is effected by the thumb screw M to suit
the known deflection of the gun on a known trajectory simultaneously) the quadrant
level is placed on a suitable piece of the gun on a plane engraved thereon, the screw K
is loosened and the level L moved so far without moving the fleeve S that it
indicates horizontal position, whereby the measuring of the angle of the land and
the transfer of the same on to the scale is effected. The screw K is then
tightened again, so that the slide S is again firmly connected with the level L &
the gun is ready to fire set both by the ordinary sights & the lateral sight V for
deflection.
If, it is desired, after firing, to sight again at the same target and same distance
it is only necessary to take the sight laterally over the quadrant sight and to see
that the level indicates again horizontal position.
If the distance is to be changed for the same target i.e. with the same land augle
the true deflection of the gun for the new trajectory is obtained from the lateral
sight V by cnce more bringing the level L with the sleeve S attached thereto by
the screw K to n horizontal position & the increased deflection due to increased
trajectory will be automatically indicated by the sight V.

page_text: Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is :-
A quadrant level for heavy guns, consisting of a clip S, which is adjustably
connected with a pivotted level L, and which in connection with the lateral sight
piece V, guided in a special slot N of the casing G indicates also automatically the
deflection of the gun for various trajectories.
Dated this 7th day of January 1896.
FELL & WILDING,
Agents for the Applicant.