Patent GB-998357-A (GB)
Title: Improvements in or relating to a device for the manual training of anti-aircraft gunsand for observation and su rveying instruments for aircraft
IPC: F41G5/08
Filed: 1962-08-20
Abstract: 998,357. Aiming devices. A. KUHLENKAMP. Aug. 20, 1962 [Aug. 22, 1961], No. 31851/62. Heading F3C. [Also in Division G1] Relates to means for aiming an anti-aircraft gun at a target in which the drive speeds for the bearing and elevational movements of the gun are set manually on the basis of target observations by optical means movable with the gun and computer tracking means is provided for assisting the operation of the gunner. The computer tracking means comprises means for computing the maximumvalue of the velocity of the bearing angle 8<SP>1</SP> in the flight plane of the target from the observed values of the beating and elevational angles #, γ, or from the velocities of such angles obtained by sighting and tracking of the target; means for the continuous computation of the values of the bearing angle #<SP>1</SP> in the flight plane to be expected for following the target, the computation using the computed maximum value of the velocity of the bearing angle #<SP>1</SP> in the flight plane as a constant; means for computing the current values of the bearing and elevational angles 8, γ for the gun from the computed value of the bearing angle #<SP>1</SP> in the flight plane and means for transmitting these last values to the tracking drives of the gun. Fig. 1 is a space diagram in which the actual line of flight of the target is represented by the line MW, the apparent line of flight being represented on the circle KMoWoL in the plane of flight of the target, which plane makes an angle # with the horizontal plane, the centre o of the circle being the position of the gun. At the actual point M or point Mo in the apparent line of flight, the target has bearing and elevational angles 8, γ which can be observed through sighting means and a bearing angle #<SP>1</SP> in the plane of flight which angle must be calculated. W is the " change point" of minimum distance from the gun O, at which the velocity of the angle #<SP>1</SP> is a maximum. This velocity W<SP>#</SP> 1max  is assumed to be a constant and a mathematical relationship can be extablished between 81 and #<SP>#</SP> 1max . As shown in Fig. 11, the sighted values of the bearing and elevational angles # e , γ e  or the angular velocities ##, ## together with the angle of elevation γ e  are introduced into a computer 85 which computes from these input values the bearing angle #<SP>1</SP> e  in the flight plane. If a lead angle has to be computed, the lead angle # contained in the input values is deducted from the bearing angle #<SP>1</SP> e  in a differential 86. The difference #<SP>1</SP> e -# is introduced into the main computer group 87 in which the maximum velocity ## 1max  of the bearing angle and from this velocity the instantaneous value of the bearing angle #<SP>1</SP> a  to be expected is computed. The velocity ## 1max  is introduced into the lead computer 88 and the lead angle # computed is introduced into both the differential 86 and a differential 89 in which is also introduced the computed bearing angle #<SP>1</SP> a  which together give an angle #<SP>1</SP> a  + # or #<SP>1</SP> aT  which is the value of the bearing angle in the flight plane for the future position. This value #<SP>1</SP> aT  is converted in a computer 90 into values # aT  in the horizontal plane and angle of elevation γ aT  which then control the aiming of the gun. The arrangement is shown in more detail in Fig. 6, but without a lead computer and in which the observed values # e , Ye are introduced into a computer part a which serves to calculate the angle of flight 8 (see the spherical right angle triangle KM o <SP>1</SP>M o  in Figs. 1 and 2) and sin 8 by means of friction discs and a cam disc 27. The value sin 8 is introduced into the computer part b which serves to calculate the angle of inclination # of the flight plane and the value sin # together with the value sin γ e  are used in part e to compute the value sin #<SP>1</SP> which is the input value into the main part d of the computing device. This value goes into comparison gear 42 into which a value sin #<SP>1</SP> KS  obtained from a displaceable cam 43 also enters. The difference sin #<SP>1</SP>-sin #<SP>1</SP> KS  is used to displace the control valve 44 of an hydraulic control which opens one of two lines 144, 244 to admit pressure oil into a cylinder 45 and to cause thereby displacement of a piston 46 so that a certain rate of displacement is associated with each position of the control valve 44. The cam 43 is firmly connected with the piston 46 and is displaced until the value sine #<SP>1</SP> is equal to the value sin #<SP>1</SP> KS . This displacement corresponds to the maximum bearing angular velocity ## 1max . The lower part of the cam 43 is formed corresponding to the angle #<SP>1</SP> KS  so that a feeler 48 moves proportionally to #<SP>1</SP> KS . This is the input value into the part e which has a similar structure to the part a. The value #<SP>1</SP> KS  turns both friction discs 49, 50 and friction rollers 51, 52 are displaded by tappets 53, 54 by rotation of a # cam disI 55 and they furnish as output values the angle of elevation γ A  and the bearing angle #<SP>11</SP> KS  in the plane of the latitudinal circle (see Fig. 2). This latter angle is converted by a cosine gear 58 and a friction roller and disc 57, 59 into the bearing angle # A , the two values γ A , # A  then being transmitted to the tracking devices of the gun.