U.S. patent number 3,638,321 [Application Number 04/874,232] was granted by the patent office on 1972-02-01 for aiming device for light weapons particularly for combating moving air targets.
This patent grant is currently assigned to Mathema Corporation, reg. Trust. Invention is credited to Hans Eglin.
United States Patent |
3,638,321 |
Eglin |
February 1, 1972 |
AIMING DEVICE FOR LIGHT WEAPONS PARTICULARLY FOR COMBATING MOVING
AIR TARGETS
Abstract
A device for determining lead values, appears with the lead
directions being represented as apparent flight directions, in the
viewing field of a telescope or reflex sight, in the form of radial
line markings. The radial line markings are associated with at
least one lead curve which is movable relative to the line markings
and is driven only as a function of the elevation aiming movement
of the weapon. Two lead curves are provided, each assigned to a
respective different target speed. The lead curve assigned to the
faster target speed is driven in accordance with the sine function
of the elevation angle of the weapon, and the lead curve assigned
to the slower target speed is driven in accordance with the cosine
function of the elevation angle of the weapon. The radial line
markings present lead markings formed by interruptions therein as
well as by their inner ends adjacent the cross hairs of the viewing
field.
Inventors: |
Eglin; Hans (Geneva,
CH) |
Assignee: |
Mathema Corporation, reg. Trust
(Vaduz, FL)
|
Family
ID: |
5716898 |
Appl.
No.: |
04/874,232 |
Filed: |
November 5, 1969 |
Foreign Application Priority Data
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|
|
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Dec 20, 1968 [DT] |
|
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P 18 15 992.7 |
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Current U.S.
Class: |
89/204;
89/41.22 |
Current CPC
Class: |
G02B
23/14 (20130101); F41G 5/08 (20130101); F41G
3/00 (20130101) |
Current International
Class: |
G02B
23/14 (20060101); F41G 5/00 (20060101); F41G
5/08 (20060101); F41G 3/00 (20060101); F41g
003/08 () |
Field of
Search: |
;33/49 ;89/41AA |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Martin, Jr.; William D.
Claims
What is claimed is:
1. In aiming apparatus, for light weapons, particularly for
combating moving air targets, and of the type including a device
for determining lead values, with the lead directions being
represented, in the viewing field of a telescope or reflex sight,
as apparent flight directions in the form of radial line markings
on a transparent plate, with the radial line markings including a
pair of radial line markings extending horizontally in opposite
directions to form a horizontal diametric line marking, the radial
line markings being associated with at least one lead curve on a
respective transparent support which is movable downwardly relative
to the line markings, and means driving each transparent support as
a function of the elevation aiming movements of the weapon; the
improvement comprising said means driving at least one lead curve
disk in accordance with the cosine function of the elevation angle
of the weapon; each lead curve being curved downwardly from the
horizontal with its curved portion terminating at points on a
horizontal line whose midpoint is aligned vertically with the
center of said diametric line marking; the lateral ends of said
lead curve extending vertically upwardly from said points on said
horizontal line; whereby lead values are obtainable at every
possible elevation angle of the weapon, as well as in pass-by
flights of the moving air target, even at the critical point.
2. In aiming apparatus for light weapons, the improvement claimed
in claim 1, including at least two lead curve supports each
corresponding to a respective different target speed; the lead
curve corresponding to the faster target speed being driven in
accordance with the sine function, and the lead curve corresponding
to the slower target speed being driven in accordance with the
cosine function, of the elevation angle of the vehicle.
3. In aiming apparatus for light weapons, the improvement claimed
in claim 1, in which said radial line markings have lead markings
formed by interruptions therein.
4. In aiming apparatus for light weapons, the improvement claimed
in claim 1, in which the inner ends of said radial line markings,
facing crosshairs in said viewing field, are spaced from said
crosshairs to present lead markings.
5. In aiming apparatus for light weapons, the improvement claimed
in claim 2, in which said radial line markings have lead markings
formed by interruptions therein.
6. In aiming apparatus for light weapons, the improvement claimed
in claim 2, in which the inner ends of said radial line markings,
facing crosshairs in said viewing field, are spaced from said
crosshairs to present lead markings.
7. In aiming apparatus for light weapons, the improvement claimed
in claim 1, including means mounting each transparent support for
movement and interchange.
8. In aiming apparatus for light weapons, the improvement claimed
in claim 2, including means mounting each transparent support for
movement and interchange.
Description
BACKGROUND OF THE INVENTION
The invention relates to an aiming device for light weapons,
particularly for moving air targets, with a device for determining
the lead values. The directions of the lead are represented as
apparent flight directions in the viewing field of a telescope or
reflex sight, and in the form of radial line markings, on a
transparent plate, associated with at least one lead curve, on a
transparent support, which is movable, relative to the line
markings, and drivable only as a function of the elevation aiming
movement of the weapon.
In such an aiming device, such as described in detail in U.S. Pat.
No. 3,263,566, it is possible to take into consideration the change
in the course of the lead values, resulting from an inclined
trajectory of the target to be combated, by a corresponding manual
modification of the zero setting of the elevation angle between the
gun barrel and the sight. By this is meant a modification between
the elevation angle, as fed by the weapon into the sight, and the
elevation angle after moving the lead curve in the sight.
Such a readjustment is disadvantageous, inasmuch as it requires
additional manipulations and inasmuch as it is not quite
satisfactory with respect to the lead values furnished.
Thus, when inclined trajectories, such as resulting from the attack
of an aircraft against objects by diving, are studied a little
closer, it will be found that the course of the lead values depends
directly upon the emplacement of the gun or weapon relative to the
target at which the aircraft is aiming.
For example, if the gun is located in front of, or laterally in
front of, the target at which the aircraft is aiming, the elevation
angle of the weapon increases in following the target, and the lead
curve moves downwardly. In such cases, the elevation angle value of
the weapon, resulting from the moment of target apprehension to the
attainment of the maximum value possible, is the one in question
for moving the lead curve disc. On the other hand, the elevation
angle, resulting from the apprehension of the target, is composed
of the angle of flight inclination and an elevation angle of the
weapon indispensable for prefeeding the curve. However, the
readjustment mentioned above takes into consideration only the
angle of flight inclination, and not the value required for
prefeeding the curve.
If, instead of the gun being located in front of the target at
which the aircraft is aiming, the gun is located behind, or
laterally behind, this target, the elevation angle of the weapon
decreases after apprehension of the target, and the corresponding
lead curve disc is moved upwardly. Since the air target pulls up
several hundred meters ahead of the land target, thus leaving the
straight trajectory, there results, for the prefeeding of the lead
curve, a relatively small elevation aiming motion, so that the
motion of the lead curve disc is hardly noticeable.
Analogous cases result from the deployment against obliquely
ascending and obliquely descending helicopters, in the tracking of
which the lead values also change but very little, due to the
relatively slow speeds.
SUMMARY OF THE INVENTION
This invention relates to aiming apparatus for light weapons,
particularly for combating moving air targets, and, more
particularly, to an improved aiming apparatus which can be used
successfully for tracking not only for aircraft moving along
inclined flight paths but also for combating or tracking
slow-moving targets, such as helicopters, which move up and down in
zigzag flight.
An objective of the invention is to design aiming devices of the
kind under discussion in an improved manner so that the above
readjustment of the elevation angle need no longer be made for
inclined flight paths of an airborne target being tracked.
Using, as a basis, an aiming device of the type described above,
the present invention solves the problem involved by making the
lead curve support drivable in accordance with the cosine function
of the elevation angle of the weapon, and by providing that the
lateral ends of the lead curve extend vertically in a manner such
that lead values are obtainable at any possible elevation angle of
the weapon, as well as when the moving air targets fly past the
weapon, even at the critical point.
In a preferred embodiment of the invention, the aiming device is
characterized by at least two lead curves, on supports, each
assigned to a different target speed. The lead curve assigned to
the greater target speed is drivable in accordance with the sine
function, and the lead curve assigned to the slower target speed is
drivable in accordance with the cosine function, of the elevation
angle of the weapon.
The lead curve moving downwardly during aiming motion of the weapon
when the flight path of the airborne target is inclined, as when
the weapon is in front of or laterally in front of the land object,
is driven in accordance with the cosine function of the elevation
angle of the weapon. Thereby, upon target apprehension or
detection, this lead curve moves by such small values that no lead
values are yet developed therefrom, or only lead values small
enough to be of no practical significance. Thus, the hitherto
required manual readjustment of the elevation angle is obviated,
which leads to a correspondingly simpler operation of the aiming
device. Another advantage is that this lead curve disc furnishes,
in addition, lead values for slow, horizontally flying air targets,
such as helicopters.
In the preferred embodiment of the invention including at least two
curve carrying transparent supports or discs, the other disc is
driven, as heretofore, in accordance with the sine function of the
elevation angle, and, therefore, is excellently suited, in a known
manner, for combating horizontally flying and preferably
fast-moving air targets.
Bearing in mind that a movement of the lead curve disc is not
necessary, because of the very small elevation aiming movements of
the weapon, resulting from inclined flight paths when the gun is
located behind, or laterally behind, the land-based object, in
accordance with another feature of the invention, the radial line
markings display lead markings formed by interruptions therein, as
well as lead markings formed by the inner ends by the radial line
markings adjacent crosshairs in the viewing field. This makes it
possible to combat, with one and the same aiming device, very
fast-moving and very slow-moving air targets, such as helicopters
flying in a so-called zigzag pattern. Lead markings of this type do
not interfere with the sighting in the viewing field of the aimer,
nor do they blur. If these lead markings were in the form of
complete curves or complete ellipses, and if they appeared in the
immediate vicinity of the crosshairs or sighting center of the
viewing field, due to the small lead values in question, the lead
curves thus developing would intersect the vertical radial lines so
that they could be confused with the crosshairs and cause lead
errors in magnitude and direction.
The line disc, according to the invention, does not have this
disadvantage, because, in the invention line disc, the lead
markings are formed by the distance between the crosshairs and the
inner ends of the radial lines, as well as by the interruptions in
these radial lines. The inner ends of the radial lines which, as
known, are closest to the crosshairs and are thus closest to the
theoretical point of impact, represent a first target distance, and
the interruptions of the radial lines represent a second target
distance. In other words, the inner ends of the radial line
markings correspond to slow target speeds while the interruptions
are correlated with faster target speeds.
An object of the invention is to provide an aiming device of the
type mentioned in which readjustment of the elevation angle, for
inclined flight paths, is no longer necessary,
Another object of the invention is to provide such an aiming device
which can be employed for combating slow-moving targets, such as
helicopters, which move up and down in zigzag flight.
A further object of the invention is to provide such an aiming
device in which the lead curve support or disk is drivable in
accordance with the cosine function of the elevation angle of the
weapon.
Another object of the invention is to provide such an aiming device
in which the lateral ends of the lead curve extend vertically in
such a manner that lead values are obtainable at any possible
elevation angle.
A further object of the invention is to provide such an aiming
device including at least two lead curves assigned to respective
different target speeds.
Another object of the invention is to provide such an aiming device
in which the lead curve assigned to the greater target speed is
drivable in accordance with the sine function, and the lead curve
assigned to the slower target speed is drivable in accordance with
the cosine function, of the elevation angle of the weapon.
A further object of the invention is to provide such an aiming
device in which the radial line markings display lead markings
formed by interruptions therein as well as by the inner ends of the
radial line markings adjacent the crosshairs of the viewing
field.
For an understanding of the principles of the invention, reference
is made to the following description of a typical embodiment
thereof as illustrated in the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a graphical illustration of the geometric relationships
and the course of the elevation aiming motions of the weapon when
the weapon, having the aiming device of the invention, is located
in front of, or laterally in front of, the object to be
protected;
FIG. 2 is a view similar to FIG. 1 showing the geometric relations
and the course of the elevation aiming movements of the weapon when
the latter is located behind, or laterally behind, the object to be
protected;
FIG. 3 is a perspective view of the driving device for the discs
supporting the lead curves of an aiming device embodying the
invention; and
FIG. 4 is a front elevation view of a line plate for an aiming
device embodying the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
To facilitate an understanding of the invention, the inclined
flight path of the airborne targets to be combated will first be
examined more closely. As indicated in FIG. 1, a gun O is placed at
a distance ekW in front of an object X being approached by an
airborne target F at an angle of inclination V. For target
apprehension or tracking, the gun barrel, which has not been
illustrated, is turned in the direction O-F, with a resultant
elevation angle .gamma.-F. When pursuing the airborne target F on
its flight path, F-X, the gun barrel executes another elevation
aiming movement, namely, .gamma.-V. If the airborne target is
pursued to the critical point eW, the gun barrel can perform an
elevation aiming motion totaling .gamma.-tot.
If a lead curve disc, provided for inclined flight paths, is
shifted in accordance with the sine function of the elevation angle
of the gun, it would furnish, upon target tracking i.e., after the
elevation angle has passed through the range .gamma.-F, too great a
lead, and the lead error would be proportional to the angle of
inclination V', because the elevation angle, required for moving
the lead curve disc must begin only from the straight line O-F'
which extends parallel to the flight path F-X. Therefore, the angle
V' has been subtracted from the elevation angle .gamma.-tot or
.gamma.-F, by a manually operable readjustment, so that there
remained, for the further motion of the lead curve disc, only the
angle .gamma.-V'.
Nevertheless, when, as will be described hereinafter in detail, the
lead curve disc is driven in accordance with the cosine function of
the elevation angle of the weapon, the motion of the lead curve
disc resulting in target apprehension, i.e., at .gamma.-F, is so
small that the value V' does not appear at all.
In the case illustrated in FIG. 2, the gun O is placed at a
distance ekW behind the object X which again is approached by an
airborne target F at an angle of inclination V. However, as
different from the example shown in FIG. 1, the airborne target F
does not fly to the point eW, but veers from the straight flight
path F-X at point D.
The geometric relations are similar to those in FIG. 1, but it has
to be borne in mind that the parallel O-F', from which the
theoretical elevation angle of the weapon should emanate, no longer
lies below the flight path F-X but is now above the flight path
F-X.
However, starting from reality, the value of the elevation angle
.gamma.-F is present in the sighting device at the moment of target
apprehension, when the barrel of the weapon points in the direction
O-F. Accordingly, the elevation aiming motion resulting during
tracking of the target from F to V amounts to only .gamma.-V as
yet. The lead curve disc movement resulting therefrom is so small
as to be of no practical significance.
Now, assuming a constant mean value for the elevation aiming
movement .gamma.-V' of the weapon, theoretically to be considered,
and calculating the lead values as a function of a mean inclined
flight path, lead markings can be plotted on the line disc, and
these correspond to that flight path and also furnish still usable
lead values even for dropping helicopters and fast horizontally
flying airborne targets underflying the weapon.
Aiming apparatus meeting the above-described contingencies will now
be described in connection with FIG. 3. Referring to FIG. 3, the
respective elevation angles assumed by the barrel of a weapon,
which has not been shown, are transmitted, by a clutch which also
has not been shown, to discs 4 and 6 mounted on a shaft 5.
Discs 4 and 6 support respective pins 7 and 8, which are mutually
displaced by 90.degree., and which engage respective slots 9 and 10
of respective transparent lead curve discs 11 and 12 which are
mounted so as to be movable and interchangeable. Lead curve discs
11 and 12 display or present respective lead curves 11a and 12a.
The discs are mounted and movable in a manner such that one of the
two discs, for example the disc 11, is driven in accordance with
the sine function, and the other disc, for example the disc 12, is
driven in accordance with the cosine function, of the elevation
angle of the weapon.
The design or calculation of the cosine transmission follows from
the assumption of a mean flight path inclination for which lead
values can be calculated in advance, taking into consideration also
the target speed and the ballistics of the weapon. In this
arrangement, disc 11, driven in accordance with the sine function
of the angle of elevation, is suited for fast, horizontally flying
airborne targets, and disc 12, driven in accordance with the cosine
function of the angle of elevation, is suited for slow,
horizontally flying airborne targets and for fast, airborne targets
approaching objects to be protected along an inclined flight path.
If follows, from the explanations relating to FIGS. 1 and 3,
therefore, that a readjustment of the elevation angle is no longer
necessary with the arrangement of the invention.
Since the upper areas of lead curves 11a and 12a are now
superfluous, these curves are so shaped that their respective ends
11b and 12b extend vertically. By virtue of this measure, the lead
curves always furnish a lead value at any elevation angle, even at
the critical point where the apparent flight direction, in pass-by
flights, always reaches 90.degree..
Taking into consideration the conditions prevailing when flights
paths according to FIG. 2 are involved, FIG. 4 represents a line
transparent disc or plate 13 which is located, as shown in FIG. 3,
in front of the lead curve discs 11 and 12. In the line disc 13
shown in FIG. 4, the spacings of the inner ends of the radial lines
13a and the interruptions in these radial lines, relative to the
crosshairs 1, are chosen so that they create lead values for
certain flights and air targets without resulting in a sighting
image which is blurred or which interferes with the field of
view.
The lead markings formed by the inner ends of radial lines 13a and
their interruptions 13b are suited, for example, for combating air
targets in whose tracking the elevation angle of the weapon
decreases. This occurs, for example, in diving attacks against
objects located in front of the gun emplacement, with helicopters
in dropping flight, with target flights taking place below the
trunnion level of the weapon, and with similar flight paths.
The lead markings formed by the inner ends of the radial lines 14a,
and their interruptions 14b, are suited, for example, for combating
air targets which are in rising flight, for example
helicopters.
The lead markings formed by the inner ends of the horizontal lines
15, and their interruptions 15a, are suited for combating airborne
targets in tracking which the weapon barrel performs no changes in
elevation.
It should also be pointed out, in this connection, that basically,
for example, the inner ends of the radial lines 13a and 14a, as
well their respective interruptions 13b and 14b, can be laid out or
designed for various target speeds, whereas those of the horizontal
radial lines 15 can correspond to various target distances but to
only one target speed.
While a specific embodiment of the invention has been shown and
described in detail to illustrate the application of the principles
of the invention, it should be understood that the invention may be
embodied otherwise without departing from such principles.
* * * * *