Patent GB-586478-A (GB)
Title: Improvements in or relating to apparatus for the training of gun fire-control instrument operators
Filed: 1944-03-21
Abstract: 586,478. Training apparatus for gun-laying, rangefinding, &c. ABBEY, A. (Arenco Aktiebolag.). March 21, 1944, No. 5288. [Class 119] [Also in Group VI] Apparatus for training gunfire control instrument operators comprises a movable target member to which is imparted a known movement by a driving device, a tracking member capable of following the movements of the target member and controlled by a setting mechanism operated by the trainee, and a recording device including a stylus mounted independently of the tracking member but operatively connected to the setting mechanism for continuously recording the movement of the tracking member upon a surface separate from the target member. In the apparatus shown diagrammatically in Fig. 1, the target member consists of an arm 19 and holder 20 for a target image or cross-wires and is swung in a predetermined path about vertical and horizontal axes by the gearing 29, 30 and cam 24, and by the gearing 32, 33 and cam 25 respectively, the motion being transmitted by concentrically arranged shafts. The two cams of known shape, which determine the target path are driven synchronously from a motor 28 through suitable gearing, the cams, motor and associated gears being mounted stationary. The tracking member 7 which forms part of a telescopic sighting device 4, 5 provided with two eyepieces 18 so that two operators can sight at the same time, is mounted to swing about the same centre as the target member and is controlled by the setting mechanism comprising hand-wheels 12 or 13 and gearing 15, 16, 17 for the movement about a horizontal axis and hand wheel 9 and gearing 10, 11 for movement about the vertical axis, in which the whole table 2 on which the target member, tracking member and setting mechanism are mounted also takes part. The motions of the target and tracking members in the vertical and horizontal directions respectively are fed into opposite sides of two differential mechanisms, the planet-wheels 43 and 38 of which are connected to styli 42 and 36 which thus record on a moving paper 47 the divergencies of the tracking member from the target member in the vertical and horizontal directions respectively. Alternatively, the differential gears can be dispensed with and the movements of the tracking member in the two directions recorded by coupling the setting mechanism through suitable gearing to an apparatus as shown in Fig. 2 in which a stylus carrier 53 may be moved in two directions by a threaded rod 54 driven from the keyed shaft 50 on which the slide 52 can move and by. a threaded rod 51 moving the slide 52. The known path 58 of the target member previously drawn on the paper and obtained from the shapes of the cams 24 and 25 can then be compared with the path 57 of the tracking member. To make the exercise more realistic, the holder 20 carrying a single image may be replaced by a device carrying a number of images corresponding to different positions of the imagined target path and arranged to convey these images one by one into correct presentation position. Alternatively, the target image may be produced by a photographic projector replacing the arm 19 and capable of similar movement. For training for direct firing weapons with two sights, one for altitude and one for horizontal aiming, the target arm is provided with two target images adjacent each other and the telescope 4-7 replaced by two sights adjustable by hand wheels for elevation and deflection respectively. In the application of the invention (not illustrated) to practice in range-finding, for example with range-finders in which a measurement drum is rotated until two images produced by two objectives are in alignment or coincidence, the measurement drum, comprising the setting mechanism, is connected by a suitable drive to a recording stylus, and two target images or marks are provided, each arranged at focal distance in front of a lens placed before an objective of the range-finder. One of the target images is driven laterally by means, for example, of a motor-driven cam disc, the sighting lines of the two range-finder objectives intersecting at the apparent distance of the target, so that the apparent range of the target changes according to the predetermined shape of the cam. The tracking member is here constituted by the objective in front of the movable target or by a movable mirror in the range-finder. Instead of recording the actual value of the measured distance, a differential device can be used, as before, between the measurement drum and the cam to record the divergence of the actual and measured distances. In Fig. 4, the invention is shown applied to a gun-laying training apparatus, the driving device comprising a cam 73 rotated by the motor 72 driving a shaft 71 through gearing 75, the shaft carrying a disc 70 having an index mark. Surrounding the disc 70 is another disc 76 loose on the shaft 71 also carrying an index which is kept in coincidence with the index of the disc 70 by the setting mechanism 77, 78, 79. The divergence between the indices is continually recorded by the stylus 83 driven from the differential device 84, 85, 87 into opposite side of which the movements of the driving device and setting mechanism are fed. The absolute value of the data introduced by the cam can be recorded by temporarily holding the wheel 87 stationary. A number of such apparatus can be combined for a corresponding number of firing data into a unit and be. provided with a common driving device. The driving device may also consist of a step-bystep receiver motor operated by a transmitter in a central fire control instrument, or by a transmitter actuated by the corresponding hand wheel 9 or 12 of an exercise apparatus according to Fig. 1, thus providing training in team work. The recording devices may each be provided with an electromagneticallyoperated recording stylus to mark the point of time, for example, of the firing of an imaginary cannon, thus determining the degree of accuracy in each case at such instant.