improvements the Laying and Pointing of tuns.
Year: 1899

page_text: improvements
the Laying and Pointing of tuns.
I, EMMANUEL DRAGOUMIS, of 22, Rue de Marseilles, Athens, in the Kingdom
of Greece, Gentleman, do hereby declare the nature of this invention to be as
follow s
This invention consists of a nearsight or telescope attached to a gun and
controlled by a depression telemeter fixed at any determined point and distance
from the gun or battery, and also controlled by the apparatus which serves to
point the gun in the direction required.
The reaisight on telescope can be controlled in such a manner, that when the
gun is properly laid, the visual line passing through the sight-hole of the rear-
sight and the edge of the foresight, or the line of collimation of the telescope,
are always directed to the point where the corresponding trajectory meets the
sui face of the sea and the end of the line measured by the telemeter When
the line joining the telemeter to the gun, and the axis of the gun are on the same
vertical plane, the range is equal to the difference between the distance measured
by the telemeter, and the horizontal distance from the gun to the telemeter
When the vertical plane in which he the axis of the gun and the line joining
the telemeter to the gun, form an angle, the range is greater than in the fore-
going case, and the distance to be added to the range of the first case, depends
upon the angle in question, upon the distance between the telemeter and the
gun, and upon the distance measured by the telemeter
In the first case a telescope or a rearsight, which comport a conecting device
for deviation, may be controlled in the said manner by a telemeter from a
distance, say through an electromagnetic arrangement, by means of-gears and
screws, the convolutions of which are properly calculated
With regard to the second case, it 18 necessary to add to the telescope or to
the rearaight, a device, which 18 controlled by the apparatus serving to point the
gun, for direction and which gives to the sight-hole of the earsight on to the
telescope, the additional movement corresponding to the aforesaid angle and
distances This device may consist of a body having a curved surface, the
different sections of which are of a form which must be calculated in every
special case according to the aforesaid data, and which turns about an eccentric
This axis is controlled by the apparatus for pointing the gun, say by
means of an electro magnetic arrangement, or by means of a cam through gear
and screws as above described.
ax18
It is evident that the same telemeter may control the rearsight of the telescopes
of different guns.

page_text: As the telemeter can be fixed at any distance from the guns, a high position
can be selected in order to use a depression instrument.
Dated this 3rd day of November 1899
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant
Improvements in the Laying and Fointing of guns.
I, EMMANUEL DRAGOUMIS, of 22, Rue de Marseilles, Athens, in the Kingdom
of Greece. 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 improvements in the sighting of guns, whereby an
automatic rear-sight is caused to operate in conjunction with a rangefinding
instrument, or a telemeter, and with the training gear of the gun, in such a
manner that the sighthole of the automatic rearsight always occupies the correct
position corresponding to the range of the point aimed at by a telemeter, fixed
at a known distance from each gun, whenever the gun to which the automatic
rear-sight belongs is trained in the direction of this same point.
The automatic rearsight may be used either for directly pointing the gun or
for giving to a telescope or a spirit level, serving for this purpose, the required
inclination and the proper azimuthal angle, when such 18 necessary.
Referring to the accompanying drawing
Figure 1 illustrates the theory of the method.
Figure 2 is a back view of the entire rearsight
Figure 3 is a front view of a part of the rearsight.
Figure 4 is a top view, and
Figure 5 a side view of this part
Figures 6 and 7 are cross sections of the corrector for direction.
Figure 8 represents parts of a device for the transmission of the rotary motion
of the axle controlling the telemeter, on the training gear of the gun.
Figure 9 represents another device for the same purpose
Figure 10 illustrates the manner in which an automatic rearsight may be used
to control a telescope serving in pointing a gun.
Figure 11 represents the principal parts of an automatic rearsight constructed,
for the purpose of compensating for deflection due to the wind or to the speed
of the target
In order to clearly explain the invention we will suppose the gun to belong
to a coast battery placed at an altitude equal to zero and that the measures of
the telemeter are taken at the level of the sea.
In Figure 1 T is the telemeter, C the gun, B the target, and B¹ the continua-
tion of the line T C We will designate T C with A, T B with D, C B with P:
the angle formed by C B and prolongation of T C with X, and the angle formed
by T C and T B with Y.
It will then be obvious that when X = 0 (zero) that is to say if the aimed point
falls on the line T B¹, P or the range of the gun will be equal to T B-A If the
aimed point B 18 situated for instance to the right of the line T B¹ (as it is the
case in Figure 1) then the range P, that is to say the distance between the gun C
and the aimed point B, will be larger than T B-A and we will call the
positive quantity which is to be added with a view of obtaining the value of the

page_text: range P
It is evident that for a constant value of the length of D the said
positive quantity vanes according to the values of the angle X and secondly
that for similar variations of the angle X the said positive quantity & varies
according to the variation of the length of D.
From these principles it will be possible to prepare a table, giving the values
of for different values of D and of X and for a constant value of A.
When X=0° then a rearsight provided with a deflection slide 18 sufficient to
give to the sighthole the position corresponding to the range P=D-A. But
in the case that X vanes, P varies too for the same D and it is necessary to
provide the rear sight with an arrangement to give to the sighthole the sureleva-
tion corresponding to the different values of D and of X. Thus the automatic
1earsight consists of three essential parts. 1. The rearsight proper 2 The pait
corresponding to the deflection slide, and 3 The arrangement for giving to the
sighthole the necessary surelevation and which we call the corrector for direction.
In Figures 25 and in Figure 11 similar letters refer to similar parts.
The earsight proper consists of a hollow cylinder a having a longitudinal
slot and fitted with a screw b of uniform or variable pitch, adapted to revolve in
the cylinder and to drive, by means of a stud d, a slider c carrying the movable
part of the instrument
The part corresponding to the deflection slide consists also of a hollow cylinder e
formed with a longitudinal slot at its lower side; in this cylinder a screw f
revolves, also with uniform, or vanable pitch, this screw drives a slider 9 by
means of a stud The said slider carries a frame h in which the sighthole
moves, which latter is normally held in contact with the drum m by suitable
springs. The revolution 18 communicated to the endless screw f by a pinion k
which is worked by the fixed rack when the slider c is moved, this rack 18
parallel to the rear-sight proper.
The corrector for direction m takes part in the movements of the slider o and
its axle is parallel to the deflection slide. This corrector consists of a drum m
of a special conoid shape and revolves about an excentric axle This drum 18
purposely calculated to communicate to the sighthole the necessary sureleva-
tions corresponding to different values of X and D Rotation 18 communicated
to the axle of the corrector by the training gear of the gun, which causes, as we
will see further on, the square barn to revolve. This bar n causes the pinion o
to revolve, which latter, carried by the branch p, can slide along the bar n and
gear with the cogwheel g which causes the axle of the corrector to revolve
The movements which the parts of a telemeter accomplish in order to measure
the distances can, in different cases (as for instance in the case of a depression
instrument or an instrument like the télémètre Le Cyre used with French coast
batteries), be communicated to them by means of a crank which causes an axle
to revolve. The rotation of this axle can be communicated by means of one of
the devices, which we will describe further on, to the endless screw 6 of the
rearsight proper and cause the slider e to move At the same time the pinion k
working with the rack causes the sorew f to revolve and drive the slider g
If in the transmission of the rotation from the telemeter to the endless screw b
the pitches of the screws 6 and f, the pinion k and the rack / are properly
calculated, the sighthole is able to occupy always the position corresponding to
the indications of the telemeter
The training gear of the gun, which can be also worked by a crank, causing
an axle to revolve, communicates the rotation of this axle, by means of one of
the devices which we will describe further on, to the bar n, and consequently
to the axle of the corrector for direction This corrector in revolving communi-
cates to the sighthole the necessary surelevation, if the transmission of the
rotation to the bain, the cogwheels and the surface of the corrector are properly
calculated.
Figures 6 and 7 show the shape and the way of construction of two such cross
sections, the one Fig. 6 when the gun tuins on both sides 90°, and the other

page_text: and c
Fig. 7 when the gun turns on one side 100° and on the other 80°. For the
construction of these sections we took in the way of polar coordinates 2 X
The length of this or the surelevation is measured in units of the
graduation of an ordinary rear sight for the range corresponding to the section;
c is a constant length, which was added in order to render the curvature of the
sections more uniform. This addition does not change the position of the sight-
hole, if care is taken to increase the distance between the axle of the correctoi
and the deflection alide by an equal length.
It remains now to describe the devices by means of which the rotation of the
axle governing the telemeter or the training gear of the gun are communicated
to the endless screw b or to the bar n respectively (Figures 2-5)
These devices
are contained in the boxes sandr (Figure 2).
These transmitting devices may be of very different description. Any suitable
device constructed on the principle of an electric clockwork can be used for the
purpose, only it must be provided with an arrangement permitting of reversal
of the movements.
We will describe only the two characteristic parts of these devices, the
commutator and the arrangement for eversing the movement, the remaining
paits being simply electic clockworks, and as such need no detailed description
heiein
Figure 8 represents the commutator, the escapement and the arrangement for
reveising, with the respective electric connections.,
The commutator consists of two metallic discs u and separated by a thicker
disk of insulating material On each of the metallic discs are fixed the metallic
contact pieces y of equal width Two metallic brushes 3 and 4 rub on the
edge of this commutator, which is duiven directly or indirectly by the axle
governing the telemeter or the training gear of the gun, respectively. Each of
these brushes is connected with one pole of the electro-magnet
Two springs
1 and 2 rubbing on the metallic discs are connected each with one pole of the
battery t
It will be understood that when this commutator revolves, the current, which
18 sent round the electromagnet v 18 continually reversed and the polarised
armature 5 oscillates causing the escapement to revolve or to be checked in its
rotation, thus driving the clockwork or regulating it
On the axle of the commutator is mounted with fiction a disc 6 of insulating
material, this disc is carried along in the rotation of the commutator till it is
stopped by two metallic projections meeting two of the three metallic projections
opposite to them This arrangement forms an ordinary commutator, which
reverses the current sent round the electromagnet was soon as the rotation of
the principal commutator 19 reversed, and thus the polarised armature 7 18
attracted to the night or left and causes the rotation of the axis 8 to change
9 18 an axle which is duiven by the clockwork, on this axle are mounted with-
out friction the bevel wheels 10 and 11, which work with the bevel wheel 12
mounted on the axle 8 which transmits its rotation directly to the endless screw b
or to the bain (Figures 2-5) The axle 9 has between the wheels 10 and 11 a
square cross section, and on this part of the axis is mounted the piece 13 of a
similar section, adapted to slide along the axle, and carrying two discs 14 and 15
between which 18 placed the polarised armature 7. Two other discs 10 and 17
fixed on the ends of the piece 13 are provided with projections which correspond
to holes of the wheels 10 and 11, when the armature is attracted to the left the
projections of the disc 16 enter the corresponding holes of the wheel 10 and
consequently this wheel is carried round in the rotation of the axle 9 while the
wheel 11 18 left free. The axle revolves in opposite direction when the armature
18 attracted to the right
Figure 9 represents a purely electromagnetic device for transmitting the
rotations On the right hand side of Figure 918 represented the commutator,
on the left a top view of the rest of the device, when the lid of the box, in which
it is contained, is removed. 1, 2, 3 are electro-magnets connected with the

page_text: contacts 1, 2, 3 of the commutator. 20 is an armature of soft iron. It is obvious
that this armature will turn in one direction or in the opposite one according to
the direction in which the bar 22 of the commutator 18 turned. Instead of an
armature consisting of a bar we may use one consisting of several bars crossing
each other the number of the bars not being a multiple of three. Likewise we
may use a commutator with more or fewer contacts.
The devices which we have described are thus able to transmit at a distance
the rotation of an axle to another axle and to reverse the rotation of this second
axle, when the rotation of the first axle is reversed. Also other devices may be
used for this result except the devices we have described simply for the purpose
of showing the possibility of the transmission in question.
The transmission as well as the calculation of the different parts of the rear-
Bight are much simplified, when equal number of turns of the axle, which governs
the telemeter, correspond to equal lengths of distances measured, if necessary
this can be obtained by using with the telemeter a cam or a screw of variable
pitch when this equality occurs the endless sciew of the rearsight proper must
be one of variable pitch, and the length of the pitch will vary in the same
proportion as the length of the graduation for range of an ordinary rearsight.
On the contrary if the number of turns of the axle which governs the telemeter
are made for equal distances proportional to the graduations for ranges of an
oidinary tearsight, the endless screw of the rearsight proper will be of a uniform
pitch It is equally possible to adopt for the endless screw f a uniform pitch if
we give to the teeth of the lack 7 (Figures 3-5) proper variable intervals.
The approximation which our automatic earsight is able to give depends
upon the speed with which the devices for the transmission can act, and upon
the maximum speed with which the concerned ranges valy
In order to give
an example in the above case of equal distances for equal number of tuins, say
that a ship approaches to or recedes from a gun with a speed of 30 knots, in this
case the range changes 15 meters in one second, and if three contacts are made
in one second, through the commutator controlled by the axle of the telemeter,
an approximation of 5 meters 18 possible. If further for each contact the endless
sciew of the earsight proper makes ¼ of a tuin, one turn of this screw colle-
sponds to 30 meters Then for a line of sight of 1650 millimeters the length of
the pitch of this screw, for langes between 2000 and 4000 meters, will be in
average 25 millimeters
It is obvious that it is possible to control from a telemeter the nearsights of
more than one gun, in this case A and X may be different for each gun.
As we are able to fix the telemeter at any desired distance from the guns, we
may choose an elevated point and use a depression telemeter with great accuracy
even for low batteries
Where batteries of not very great altitude are concerned the difference between
the real range and the range reported to the level of the sea, 18, for all practical
purposes, a negligeable quantity.
The automatic rearsight which we have described is especially destined for
coast batteries, but it may serve in many cases also for other guns, in connection
with a telemeter, which can be governed by the rotation of an axle
The automatic rear sight may also bear graduations according to the ranges
At the beginning of every series of firing, by acting directly on the screw b by
withdrawing the set screw d (Figures 3 and 4) and driving the slider e by hand,
we may make the rearaights controlled by a telemeter to concord with its indica-
tions, that is, to mark ranges equal to D-A Now the set screw d being put
again in its place if necessary the automatic rear-sight is ready to work.
An antomatic rearsight, on the principle of the one already described, may be
used in the cases in which the aim is taken by means of a telescope or of a
spirit level to give to these instruments the inclination corresponding to the
range of the point aimed at by the telemeter as well as the proper azimuthal
angle if such required.

page_text: Figure 10 indicates the manner in which the movements of the sighthole 25
of an automatic 1earsight may be transmitted to a telescope 23, 25 bears a pin
instead of a hole, this pin is made to slide in a slot along the lower part of the
rod 24 This 10d 18 not straight but angular in order to allow of the eye
approaching the eyepiece of the telescope 23 In analogous manner the move-
ments of the sighthole may be communicated to a spirit level. In these two
cases the different parts of the automatic rear sight, transmissions, screws, lack,
pinions, corrector of similar device must be especially calculated.
Figure 11 represents a variation of my rearsight, which allows for the deflection
caused by the wind or the speed of the target. 26 and 27 are axles the part of
which contained between p and has a square cross section. Along these axles
can slide the endless screw f and the drum m of the corrector for direction
iespectively The endless screw 28, which passes through supports fixed on the
piece and on the slider c drives, when turned by means of the head 29, the
plate 31. This plate which enteis in grooves of f and m without interfering with
their rotation, communicates its movements to these bodies and displaces hou1-
zontally the sighthole, without changing the respective position of the sight-
hole and the dium m The 10d 30 serves to guide the slider 9 and the plates 31
and prevent them from turning This rod or one of the axles 26, 27 may bear a
graduation for the measure of the deflection Instead of displacing the sighthole
in one direction it is possible to give the same deflection by displacing the fore-
sight in the opposite direction If we use a foresight moveable on a line parallel
to the axis of the trunnions of the gun, we are able to give through its displace-
ment the desired deflection in order to account for the wind or for the speed of
the target, with a rearsight of the first kind A pinion and rack can communi-
oate to the foresight the necessary movements. This pinion if fixed on a long
axle can be worked from a point near the rearsight. Instead of using one move-
able foresight, we may use several foresights fixed in equal distances on a line
parallel to the axis of the trunnions of the gun These foresights may be
differently painted in order to be easily distinguished. According to the deflec-
tion which must be given, the aim will be taken through one or the other of these
foresights. If more accuracy is desired, the whole row of foresights can be made
to move in a duection parallel to itself on a space equal to half the distance of
the middle of one foresight to the middle of the next one The same result will
be attained if the whole rearsight of the Figure 2 18 capable of being displaced
along a line parallel to the axis of the trunnions of the gun
The manner in which the automatic rearsight is to be fixed to the gun must
be specially studied for each particular case If the case requires it, the position
of the different parts of the automatic rearsight can be changed in different ways,
for instance the rack with the pinion (Figures 2-5) as well as the bar n, and
the cogwheels q and o, may be arranged on the side of the rearsight proper a,
with the corresponding device s for the transmission of the rotation
The automatic rear sight works continually all the time the telemeter is follow-
ing the aim, and the gun 18 trained towards the same, even if detached from
the gun
Having now particularly described and ascertained the nature of my said
mvention and in what manner the same is to be performed, I declare that what
I claim is
1
1 An automatic rearsight controlled by a telemeter fixed at known distances
from one of several guns, to which the rearsight belong, and also by the training
gear of the gun, in such a manner that the sightholes of the rear sights always
occupy the proper positions for the ranges of the point aimed at by the telemeter,
provided that the gun 18 trained towards this same point, the parts of the
automatic rearsight occupying indifferently the respective positions indicated in
the Figure 2 or any other positions, substantially as set forth and described.
2. The combination of the endless screw 6 of a uniform or a variable pitch

page_text: with the slider c and the rest of the moveable parts of the automatic rearsight,
substantially as set forth and described
3 The combination of the endless screw f of a uniform or a variable pitch
with the pinion k and the rack in order to drive the slider which bears the
sighthole and thus to give to the sighthole the necessary horizontal displace-
ment, substantially as set forth and described
4 The combination of the sighthole with the frame h, which allows the sight-
hole to receive the necessary surelevation and horizontal displacement, sub-
stantially as set forth and described.
5. The corrector for direction which gives to the sighthole of the nearsight the
surelevation corresponding to the range and to the direction of the aiming,
substantially as set forth and described.
6 The combination of the commutator with the axle which governs the
telemeter as well as the combination of the device for transmission with the
endless screw of the nearsight proper, which combinations produce the tians-
mission of the rotation of the axle, which governs the telemetoi to the endless
sciew of the rearsight proper, and consequently the proper displacements of
the parts of the automatic rearsight, substantially as set forth and described
7 The combination of the commutator with the axle which goveins the
training gear of the gun as well as the combination of the device for transmission
with the bar n which combinations produce the transmission of the rotation of
the axle governing the training gear of the gun to the corrector for duection,
substantially as set forth and described
8 The combination of the automatic rearsight with a telescope or a spit
level in order that these instruments when used to take the aim, may receive the
necessary inclination and azimuthal angle if required, substantially as set forth
and described
9 The combination of the endless screw f and the drum m with the axles 26
and 27 and with the endless screw 28, which combinations produce the horizontal
displacement of the sighthole, without changing its respective position to the
drum m, and thus account for the deflection required by the wind or the speed
of the target, substantially as set forth and described
10 The combination of the automatic rearsight with one moveable foresight
or several fixed or moveable foresights in order, to account for the deflection
required by the wind or the speed of the target, substantially as set forth and
described.
Dated this 3rd day of August 1900
HASELTINE, LAKE & Co,
45, Southampton Buildings, London WC,
Agents for the Applicant