US 3091035 A
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A. KUHLENKAMP ORDNANCE SIGHT May 28, 1963 4 Sheets-Sheet 1 Filed May 14, 1958 A/fredhl/hlenkamp Inventor? XJJVM May 28, 1.963 A. KUHLENKAMP ORDNANCE SIGHT Filed May '14, 1958 4 Sheets-Sheet 3 Alf/P0 Ruble/rial Inventor X 1 ,fwzw
Aifomey May 28, 1963 A. KUHLENKAMP ORDNANCE SIGHT 4 Sheets-Sheet 4 Filed May 14, 1958 A frec/ Au/z /e nkam Q, INVENTOR ATTORNEY United States Patent Oflice 3,091,035 Patented May 28, 1963 3,091,035 ORDNAN CE SIGHT Alfred Kuhlenkamp, Braunschweig, Germany, assignor to Mathema Corporation Reg. Trust, Vaduz, Liechtenstein, a corporation of Liechtenstein Filed May 14, 1958, Ser. No. 735,322 Claims priority, application Germany Aug. 22, 1957 3 Claims. (Cl. 3349) My main patent Application Serial Number 449,123, which became Patent No. 3,024,536, issued March 16, 1962, is concerned with an aiming arrangement for weapons to combat moving targets such as aircraft, in which there are determined the contact points in a sighting device through the aiming-oft (lead) values in respect of magnitude and direction for a single mean rectilinear path which traverses the aiming range of the weapon, in dependence upon the bearing angle and angle of elevation of the weapon, and wherein more specifically the aiming-off values are produced in the aiming arrangement as angles in the flight plane. A further proposal in accordance with the said main patent application resides in that the direction of the aiming-off is made known through the apparent direction of flight. The direction of the flight path in respect of the weapon in the aiming arrangement is adjustable as to the setting aircraft from left, aircraft from right and aircraft from in front. The aiming-off values of the computer arrangement of the sighting device are made known in the field of view of the sighting device through a group of curves which relate to a plurality of speeds of aircraft. The computer adjustments of the aiming arrangement emanate from curved bodies in conjunction with registering or feeler members operative therewith.
According to the present invention there is provided an aiming arrangement for weapons to combat moving targets such as aircraft, in accordance with my above cited patent, wherein a deviation arising from a regulation of one of the settings aircraft from left, aircraft from right or aircraft from in front and the apparent direction of flight in the field of view of the optical means is correctable in that a value for the slope of the angle of the flight plane, automatically determined through a computer mechanism in the sighting device and rendered readable by an indicator arrangement through the disposition of an edge member and which, on the basis of the geometrical relationships, for an erroneous regulation is continuously varied, can be rendered stationary by a manually introduced correction to the initial regulation.
Further adjustments may be made with corrections to the three formerly possible settings aircraft from left, aircraft from right, aircraft from in front.
which produced deviations from the actual course of the flight path. Furthermore they may be concerned with the improvement of the computer regulation of the sighting means for the effect of alteration in altitude of the flight path and finally also for the effect of a canted, i.e. not horizontal, disposition of the Weapon on the computation of the aiming-off values. For the solution of these additional problems there are spherical relationships which relate to the sphere associated with the flight plane. In particular there is made use of the fact that the angle of inclination of the flight plane is only constant when the initial bearing angle of the flight path is correctly chosen thereby to produce the correction for the apparent direction of flight.
In accordance with a feature of the invention there is produced the angle of inclination of the flight plane in dependence upon the bearing angle and the angle of elevation, in accordance with the formula tg=tgy/ sin by means of a curved cam.
With a change of altitude of an aircraft there is introduced no alteration, as compared to an aircraft flying at a constant altitude, to the requisite determination and to the apparent direction of flight. On the contrary, the relationship of the aiming-off values is varied to such an extent that there is introduced a displacement of the aiming-off values in relation to the values of the angles of the apparent direction of flight.
Should displacement of the aiming-ofl curves in relation to the apparent direction of flight not be taken into consideration, there are thereby derived aiming-off values which in respect of the direction are correct but are not so in respect of magnitude.
These disadvantages are avoided in accordance with a feature of the invention in that with an alteration of altitude of the aircraft the adjustment of the estimated angle of inclination of the aircraft to the horizontal plane is accomplished by an operable knob operating by means of a computer mechanism for the automatic additional rotation of a disc having aiming-off curves thereon in the sighting device. As computer mechanism there may be utilised a curved body which is formed in accordance with the equation sin r=sin v/sin 1'.
With a canted disposition of weapon there is a deviation with respect to the horizontal plane, of the plane in which the Weapon rotates in respect of its bearing angle, this deviation being determined by the direction in which the greatest angle of cant lies. The inclination of this weapon plane to the horizontal plane has the effect that the aiming-off values defined through the computer arrangement in the sighting device, are, so far as the effect of an altitude change is concerned, exactly correct as to direction but not as to magnitude.
This disadvantage is overcome in accordance with a feature of the invention in that the cant of the weapon plane is calculated in a similar manner as utilised for an alteration in altitude of the flight path on the basis that operationally it is immaterial whether the flight path lies horizontal and the weapon plane is inclined or whether the weapon plane lies horizontal and the path of the aircraft is inclined. A preferable solution is achieved by the insertion of a maximum angle of cant determined by the use of a water level which is rotatable and displaceable in respect of magnitude and direction by operational knobs at the sighting device and the inserted maximum angle of cant serves through a computer mechanism to produce the derivation of the canting or correction for variation of altitude of the aircraft. For this purpose there is utilised in accordance with a feature of the invention a curved body which computes from the value of the greatest angle of cant and from the angle, derived from a differential, between the axis of cant and the track line of the flight plane, the cant corresponding to the angle of inclination of the aircraft in accordance with the formula sin v=sin m/sin E. Thereby the cant corresponding to an angle of inclination of the path of the aircraft is correctively applied through the same curved body as is utilised for the calculation of the correction for a variation in altitude, in effecting the setting of a disc with the aiming-off curves in the si hting device. The additional angle for the correction of the parabolic form of flight of the shot is taken care of in the sighting device by means of a curved plate, which in dependence upon the bearing angle is displaceable by a suitable drive.
The limit of application of the sighting device with a reflecting optical means described in the said patent referred to above is determined by the range in which a target can be apprehended or spotted by means of the naked eye. The magnification of the range of the weapon and the sighting device takes place in accordance with a feature of the invention in that the reflecting optical means is replaced by a telescope with a magnification of about three power. Since the extent of the field of view of the telescope becomes smaller to an extent dependent upon the increase in the magnification it is consequently not possible to extend the aiming-off range in the field of vlew of the telescope beyond about plus or minus 30.
On the basis of these considerations an arrangement in accordance with a feature of the present invention utilises in the sighting device a telescope which is so mounted that it is on the one hand rotatable in the direction of the apparent direction of flight and on the other hand is swingable in respect of the aiming-off angle. A further consequence of the utilisation of a telescope is that it is no longer possible simultaneously to produce contact points for various target speeds in the field of view. Therefore in accordance with the present invention there are derived with the aid of a computer mechanism, as for example a curved body, the requisite aiming-off values for specific manually inserted speeds of the aircraft and these values are transmitted over mechanical drive members to the axes of the telescope. Preferably there is utilised a curved body which is such that it supplies the aiming-off values in dependence upon the speed of the aircraft and the bearing angle in the flight plane as a rotational value through a register or feeler member contacting the curved body.
Reference is now made to the accompanying figures of the drawings which illustrate embodiments of the present invention here given by way of example.
FIG. 1 shows in perspective the technical functioning of an assembly for a sighting arrangement with the novel correctional means in accordance with the present invention. A reflecting device continues in this embodiment to be used as an optical means.
FIG. 2 shows the geometrical bases for the case of alteration of altitude of the target,
FIG. 3 is a diagrammatic view showing a geometrical method for canting the Weapon,
FIG. 4 is a perspective illustration of an embodiment of the sighting arrangement utilising a telescope as sighting optical device,
FIG. 5 shows the field of view of the telescope with the small central circle as contact point and the rotational radial line that is required from time to time to be brought into correspondence with the longitudinal axis of the aircraft and FIG. 6 is a perspective view of a detail showing of the clutch member and its associated parts.
As a criterion for the degree of departure from actual values which is involved in the assumption which is made by the setting aircraft from left, aircraft from right, aircraft from in front in respect of the initial bearing angle and thereby also for the flight angle 6, there serves the angle of inclination -r of the flight plane. As can be seen from FIG. 2 the angle of inclination 7- remains unchanged for the entire horizontal or inclined flight path. Through the setting for the above mentioned initial value there is thereby chosen the null direction for the derivation of the bearing angle which coincides with the direction of the track line NM. From the value of the hearing angle 0' derived from the null direction and the angle of altitude 7 there is derived the angle of inclination 'r of the flight plane (in accordance with the equation lgr=tg'y/Sino). With incorrect choice of the null direction the sloping plane in which lie the track line and the various positions of the aircraft, is not at this point the flight plane. The sloping plane alters with variation of the aircraft position as to its angle of inclination 1-. Variation in the angle of inclination 'r in the direction of larger or smaller values shows that a correction is required in one or the other direction in respect of the initial setting for the track line and the null direction so that the value of the bearing angle is thereby indicated. The correction is no longer required when the angle of inclination 'r undergoes no further alteration.
A technical mechanism for the solution of this problem is shown in the representation of the assembly of a drive construction for the sighting device in FIG. 1. The movement for the bearing direction of the Weapon (TG is transmitted through the coupling 3 and clutch 15 to the sighting device. With the clutch 15 in disengaged position the associated drive is uncoupled from the sighting device. By rotation of the knob 23 there is inserted in this uncoupled condition of the drive an initial value dependent on the choice of the position aircraft from left", aircraft from right, aircraft from in front. The disengaged position of the clutch 15 is held firm through a catch 24 until by pressing on the knob 27 the catch is released and the clutch 15 is engaged. The bearing angle 0 is then transmitted through the engaged clutch 15, toothed disc 14, bevel wheels 18, toothed cylinder 19 to the axis of the pair of curved bodies 11, 12, of which the curved body 11 is the one from which there is supplied a rotational value of the registering member 39 as the sought angle of inclination of the flight plane. In addition to the rotation with respect to the longitudinal axis corresponding to the angle O'G the curved body undergoes an axial displacement in that a slide 9 provided with a rack is coupled on the one hand with a curved body and on the other hand is driven through a pair of bevel wheels 8 and coupling 4 proportionately to the angle of elevation 'y of the gun barrel.
The rotational value for the registering or feeler member 39, which is proportional to the angle of inclination of the flight plane, rotates, through toothed drives 40, 46 and 49 an apertured indicator 50 relative to a fixed scale 53. The viewable edge 50 of the aperture of the indicator 50' serves as an indicating means. If the edge 50 remains stationary in relation to the scale 53 during the course of following of the target the initial value for the adjustment by the knob 23 is indicated as having been a correct one. Should the edge 50 move in one or the other direction then there is to be introduced by rotation of the knob 23 in one or the other direction a correction value to the bearing angle a derived from the weapon until the edge 50 becomes stationary with respect to the scale 53.
Variation of Altitude When the aircraft varies its height either due to its climbing or failing the geometrical relationships vary from those applicable for a horizontal flying target (FIG. 2). In the flight plane the course of the aircraft path is no longer parallel to the track line NM but in this case forms with it an angle. The change point W, at which the target comes closest to the position of the weapon 0, becomes separated from the point P on the flight path at which the angle of elevation has its maximum value, in a manner such that the change point is displaced with respect to the point P in the direction of reduced height for the target. In the flight plane the course of the range from the weapon to the various points of the flight path remains symmetrical with respect to the change point as for a horizontal flight path. There then occurs also no alteration as to the course of the aiming-ofi values in dependence upon the bearing angle a'. On the other hand the relationship of the value of the flight angle 5 to the aiming-01f values A becomes altered. For a horizontal flight path the flight angle 6 is a right angle when the aircraft is at the change point, and in the represented example the flight angle 6 is first a right angle at the point P which lies behind the change point. There occurs therefore a displacement of the course of the angle of flight in respect of the course of the aiming-off values and in a manner such that the angle of flight 6:90 for a climbing flight path first at a position after the change point, and for a falling flight path before the change point is reached. This displacement can be expressed as a correction angle to the bearing angle in the horizontal plane.
The correction angle K is calculated from the angular relationships in the right angled spherical triangle Q MQ which is formed when there is drawn through a parallel to the inclined flight path. In this triangle there is the arc Q Q for the angle of inclination of flight v. In the triangle there is the formula Therefrom it is to be assumed that the angle of incli nation of flight v can at a maximum equal the angle of inclination 1- of the flight path and that in this case the correction angle 1::90". The aircraft would then be directed on a path directly in line with the weapon The angle of inclination 1- of the flight plane is also simultaneously the limiting value for the range in WhlCh the angle of inclination of flight v can vary.
The separation of the change point W from the point P at which the angle of elevation 'y attains its maximum and is equal to the angle of inclination 'r of the fl ght plane, connotes that the relationship between the aimingoff angle A, (which is computed in dependence on the deviation of the location of the aircraft from the change point and represented on the curve plate 36 (FIG. 1)) and the position of the radial mark on the d1sc 31 (FIG. 1), which gives angle of flight 5, is altered. While for a horizontal flight target for an angle of flight 5=90 (i.e. for a horizontal disposition of the mark indicating the direction of flight on the disc 31) the aiming-cit values apply which relate to the change point, for a rising flight path the aiming-off value which pertains to the change point W is for a flight angle 6 Which 1s smaller than 90 and for a falling flight path to a flight angle 6 which is greater than 90. The displacement is determined through the angle :c which appears as an arc W P and also as the arc Q M on the great circle NP M. From the spherical relationships in the already mentioned right angle triangle Q MQ there is derived SlIl K'=s1n v/srn 'r.
Therefrom there can be calculated the correction angle K from the estimated angle of inclination of flight v and the inclination angle 1- of the flight plane In FIG. 1 there is set forth a technical mechanism for the solution of this equation within the assembly construction of the sighting device by way of example. The angle of meltnation of flight v is inserted for example in steps of 10, 20 and 30 by rotation of the knob 51 and the indicator 52 with respect to the scale 53. The edge 50 of the cap shaped number 50', which adjusts itself in accordance with the angle of inclination 1- of the flight plane, shows the momentary possible limiting value and thus facilitates the estimation of the angle of inclination of flight. The rotation of the regulating knob 51 operates over a pulley wheel 74 and a cable 59 to effect the displacement of registering lever 60 in an axial direction of the curved correction body 57. The curved body 57 is moreover rotated about its longitudinal axis by means of registering member 39, which is rotated proportionally to the angle of inclination 1- of the flight plane and drives body 57 through toothed wheels 40 and 56. The rotational value of the registering member 60 is proportional to the correction angle K. This is added or subtracted through the toothed cylinder 61 in the differential 33 to the bearing angle 0'', dependent upon whether a climbing or falling target is being dealt with. The so corrected bearing angle a'i-x displaces the transparent disc 34 with aiming-off curves 34" and the correction angle plate 58. The requisite provision for the correction angle a follows in this case from the displacement of the objective 45 through the correction angle plate 58. The curve of the plate 58 comprises a correction angle in dependence upon the bearing angle 0" for a target flight for a ballistic missile in correspondence to a mean range of change point and a mean angle of inclination T of the flight plane of for example an angle of 45.
Canting Correction The geometrical basis for the sighting device undergoes an alteration as soon as the weapon on which the sighting device is found is not horizontal or cannot be rendered horizontal as is for example the case with a self-driven mountings. The geometrical relationships are illustrated in FIG. 3. The weapon rotates in the plane gwhich is canted with respect to the horizontal plane j The cant in respect of magnitude and direction is defined through the direction of the axis OV, about which the canting takes place, and through the angle enclosed between the weapon plane y and the horizontal plane Z With OG as the null direction, from which in the canted weapon plane the bearing angle is measuredthe null direction can be for example the longitudinal axis of the vehicle on which the weapon is placed-the disposi tion of the canting axis is defined through the bearing angle 1 The canting angle as an angle of slope of the weapon plane with respect to the horizontal plane g is given by the angle e between the two planes at the point V. The direction and magnitude of the cant can be determined from a water level which is first turned in the direction of maximum indication and is then made horizontal.
The flight plane f/ for a horizontal course of target path MWP cuts the horizontal plane 5/ in the track line NO which runs parallel to the flight path. The flight plane cuts the canted weapon plane y in the track line N which no longer runs parallel to the flight path, but, as with a flight path which undergoes variation in altitude cuts this at some finite point. The disposition of the track line N'O in the weapon plane y is defined through the bearing angle av reckoned from the null direction OG. By spherical projection of the point N in the horizontal plane there is derived the point N" and thereby the right angled spherical triangle VN"N' in which NN" is the are for the angle of inclination of the flight v corresponding to the canting e. The effect of the canting can thereby be traced back as to a variation of altitude and thereby the canting be taken into consideration in the same manner as a variation in altitude. The arc VN' subtends the angle 0 which can be indicated by a From the right angle triangle VNN" there is derived the equation sin v=a sin e.
The technical solution for the mechanism for solving this problem is by way of example set 'forth in FIG. 1.
The maximum angle of cant e derived from a water level is inserted through the knob 63, the disposition of the canting axis being inserted through the knob 69 as angle a The value of the rotation of the knob 63 is transmitted over the spindle 64 and nut 65 as a displacement to the curved body 66, which is so formed that it supplies as a resultant value the sought angle of inclination v in correspondence to the given mathematical equation, in that it is turned and displaced, respectively, in proportion to the angle o' and the canting angle 6.
The angle a between the canting axis 0V and the track line NO is provided in that the bearing angle a' calculated in relation to the nul direction 0G for the momentary direction of the weapon is fed into the diiferential 71 which has as a second value from the regulating knob 23, through a toothed Wheel, an initial bearing angle M0N'=a. The sum or difference of these two values is subtracted in the differential 72 from the inserted value of the angle a set in by the knob 69, which gives the disposition of the canting axis, so that as a further difference there emerges the bearing angle a' in accordance with which the curved body 66 is turned. The registering or feeler member 67 transmits the derived value v over the pulley 68 as a displacement to the registering lever 60 which then transmits the correction value K, as already described for the correction in respect of variation of altitude to the disc 34" having aiming-01f curves and the correction plate 58.
T eleseope in Place of Reflecting Optical Device For the utilisation of a sighting device with Weapons of large calibre it is necessary to replace the reflecting optical device with a telescope with corresponding optical magnification in order that the aircraft at great distances can be followed by the eye.
The telescope which is inserted instead of the reflecting optical device must be so mounted that it can be turned with respect to one axis proportionally to the flight angle and with respect to a second axis proportionally to the aiming-off angle A. Thereby as a difference from the reflecting optical device the aiming-off angle A requires to be produced as a proportional rotational movement of a shaft and for this purpose there is required to be provided additionally a computer mechanism through which there is calculated the aiming-off angle A in dependence upon the bearing angle a" and the speed of the aircraft V. In other respects the assembly of the sighting device does not vary from the utilisation of a reflecting optical means.
In the illustration of the mechanism in FIG. 1 of the assembly construction for a reflecting optical device the reflecting optical parts 41, 45, 34", 31" and the illuminating arrangement 5, 42, 43, 44, 54 and 62 are omitted. In place of the reflecting optical device there is inserted the telescope 45 as shown in FIG. 4 which is rotatable about one axis 73 with shaft means mounted in a rotational manner in a toothed ring 31. On the axis 73 there is mounted a bevel wheel 83 which is coupled to a bevel wheel 82 and which together with a spur wheel 81 lies on a common sleeve 85 in which the telescope 45' is freely movable. In the optical system of the telescope 45 there is disposed in the central region of the field of view a mark which is formed as a point or a ring with a radial line extending on either side thereof (FIG. 5). The line is always maintained at right angles to the axis 73 and forms with respect to the vertical axial plane of the telescope the flight angle 5. The telescope 45' is turned by means of toothed wheel 28' and toothed ring 31 with respect to its longitudinal axis in correspondence to the flight angle 6 which, as shown in FIG. 1 is calculated by curved body 12 and differential and transmitted through toothed drives 21, and 26 as a rotational value to the telescope.
The aiming-off angle A by which the so-rotated telescope is required to be swung with respect to its axis 73, is derived with the aid of curved body 34. The curved body is formed for the aiming-off angles A which apply for a range of speed of the aircraft from 0 to about for example 900 kilometres per hour on the basis of a mean flight path in dependence upon the bearing angles 0" in the flight plane. It replaces in this manner the disc 34" with the curves thereon which comprise the aiming-off values only for three speeds of aircraft.
The aiming-off angle A curved body 34' is displaceable axially of shaft 74' on which it is mounted and is turned through drive members from the registering member 32 of the curved body in correspondence with the bearing angle a in the flight plane. Besides this it is axially displaceable through a coupling fork 76 which is secured to the nut of the worm spindle 77 and is rotated by the turning of the knob 75 in correspondence with the chosen speed of the target. The registering member 78 is turned proportionally to the sought aiming-off angle A and transmits this over bevel gears 79 into the differential 22 into which moreover there is connected the rotational value (flight angle 6) inserted through toothed wheel 28'. The sum, or the difference, of these two turning values operates over toothed wheels 80, 81 for the rotation of the sleeve 85 and through bevel gears 82, 83 for the rotation of the telescope with respect to the axis 73.
Assembly Construction FIG. 1 shows the drive arrangement and the operation of the sighting device with a reflecting optical device.
In the sighting device there are transmitted the values of the bearing angle 0 and the elevational angle 7 derived from the directional movements of the weapon through couplings 3 and 4. The elevational angle 0' is transmitted from the coupling 4 over a toothed drive 8 to a rack 9 which is formed as a cog and displaces the curved bodies 12 and 11 as well as the curved body 13 in an axial direction in accordance with the angle a. The bearing angle is transmitted by way of a clutch 15 and toothed drive 14 on the one hand through the bevel gears 16 and toothed cylinder 17 as a rotational value to the curved body or cam 13, and on the other hand over bevel gears 18 and toothed cylinder 19 as a rotational value to the pair of curved bodies or cams 11 and 12. By pressing on the turning knob 23 there can be coupled in by the help of the clutch 15 the inserted value of the bearing angle derived from the gun mounting and the computer mechanism disconnected. The catch means 24 ensures that the coupled position is maintained until it is again lifted by operation of the knob 27 on completion of the setting in of the initial bearing angle as the observer first gets his sights on the target.
The value which is derived from the curved body 12 with the aid of the registering lever 29 is transmitted into the differential 10 into which there is also fed the value a from the toothed cylinder 19 by means of the gears 20. By addition of these two values the differential supplies as a rotational value the flight angle 6 which turns the marked disc 31 through gears 21, 25, 26 and 28. The value moreover turns the disc 34" with the aiming-off curves 34" through the differential 22 and the gear 30.
The registering lever 32 transmits the value from the curved body 13 through the differential 33, gears 35, 36 and 37 and moreover through the gears 7 and the correctional plate 58 which serves to displace the objective 45.
The curved body or cam 11 supplies the angle of inclination of the flight plane which turns the registering member 39 through the gears 40, 46, 49 to rotate a marker 50 which simultaneously serves as the sighting means for the regulation of the value of v. By the gears 56 there is transmitted the value of the curved body 11 simultaneously as a rotational value to the curved body 57 which comprises a correctional value It for the bearing angle a with alteration in altitude of the flight in dependence upon various angles of inclination of the flight angle v. There is set by the knob 51 the angle of inclination by the aid of a pointer 52 reading against the fixed stationary location scale 53, and, by means of the cable disc 74 and the cable 59, the registering member 60 is displaced in an axial direction. The registering member 60 supplies the value 1c of the curved body 57 through the toothed cylinder 61 into the differential 33 where the subtraction of a takes place.
With canting of the weapon, the maximum angle of cant, previously determined by means of a water level, is inserted by knob 63. This value displaces the curved body or cam 66 in an axial direction by means of the spindle 64 and the nut 65 having projections engaging the ends of cam 66. The registering member 67 takes from the curved body 66, which moreover is turned in accordance with the bearing angle 0,, the value v and transmits it over the cable pulley 68, which operates in cable drive 59 as a differential, to the registering member 60 as an axial displacement. In the differential 71 the bearing angle a, derived from the insertion knob 23 through the gear 70, is subtracted from the bearing angle of the weapon or added thereto. This sum or difference, 0' enters the differential 72 in which the value a, set in by means of the adjusting knob 69 (for the angle between the longitudinal axis of the vehicle and the axis of cant FIG. 3 as determined by manipulation of a water level as described above) is subtracted from it to form the value 0 which serves to turn the v curved body.
The reflecting optical device is illuminated by artificial light or daylight. From contact leads 5 the electrical current is fed from an outside source through a regulating resistance 43 to the reflector 42. There is utilised, by means of the control switch 62, the mirror 44 which, with 5 artificial illumination is made to stand vertically to cover the glass Window 54, and which, with daylight, is made by means of the switch to take up a 45 position. The daylight then falls through the window 54 and is deflected by means of the mirror 44 upwards into the optical device.
1. Apparatus for aiming weapons intended to combat mobile aircraft targets comprising a control knob having positions determined by the meatibir'or the aircraft relative to the gun position, ie aircraft approaching from the right, aircraft approaching from the left or aircraft approaching from the front, a c ornputing cam element connected to be operated by said knob, means for adjusting said cam element by the elevation gear of a sighting weapon, a manually operated coupling adapted to connect the azimuth mechanism of the weapon to the computing cam element after the target is picked up by the sighting apparatus, whereby the computing cam element continues to be driven governed by the azimuth mechanism, a follower positioned by said cam element in proportion to an angle between the plane of flight and the horizontal plane, a second computing cam element rotatable with the first cam element, a second follower cooperating with said second cam element, means displacing said second cam in proportion to the bearing angle of the 30 weapon in the horizontal plane through said coupling, a
sighting apparatus having a path of light and including two 1 discs one of whicli'is provided with a radially disposed slotand being rotatable by said second follower and the other i of which is a transparent disc lying in said path of light ,35
and provided with a series of curves indicating aiming-off 3 values, and means for rotating said transparent disc by both of said followers, a third computer cam element l connected to be operated by the control knob, a third follower cooperating with and contacting the third computer 40 vcam element and turning in proportion to the bearing angle in the plane of flight, SaiiSighL g apparatus including a rgflegping ptical device to reflect light through the sighting apparatus, and an indicating device connected to indicate the position of the first-named follower.
2. Apparatus according to claim 1 in which the angle of slope 1- of the flight plane is produced in the first mentioned computing cam element in dependence upon the bearing angle o' in the horizontal plane and the angle of elevation 'y in accordance with the formula tangent 1= 5 sin a the first mentioned computing cam element being rotatable proportionately to the bearing angle v in the horizontal plane about its longitudinal axis by the recited displacing means after adjustment of said knob, said displacing means including a toothed drive, and said apparatus including a coupling and toothed drive connected to axially position the first mentioned cam element relative to the first mentioned follower in proportion to the elevation angle 7 by the elevational movement of the weapon, said first mentioned follower being pivotally mounted to provide the required angle of slope 1- of the flight plane as a rotary value.
3. Apparatus according to claim 1 including a computer mechanism to correct for a variation in the altitude of the aircraft, having a knob for setting thereinto the angle of inclination of flight v of the aircraft to the horizontal plane, said last mentioned computer mechanism serving for the automatic correctional rotationof said transparent disc with aiming-offpurves in the sighting device.
References Cited in the file of this patent UNITED STATES PATENTS 2,372,613 Svoboda Mar. 27, 1945 2,407,191 Tear et al Sept. 3, 1946 2,539,501 Weiss Ian. 30, 1951 2,577,785 Lyon Dec. 11, 1951 2,579,510 Nagy et a1 Dec. 25, 1951 2,609,606 Draper et al Sept. 9, 1952 2,693,031 Clark Nov. 2, 1954 FOREIGN PATENTS 1,094,648 France Dec. 8, 1954