GB309073A - A process and apparatus for reproducing contour lines on maps - Google Patents

Abstract

309,073. Coradi, G. April 4, 1928, [Convention date]. Pantographic apparatus is employed for reproducing the contour lines of a map in such a way that, on the reproduction, they are relatively displaced a definite amount. in order to produce a perspective view. As shown in Fig. 1, the contours I. II, III on a map 4 are reproduced on the same or modified scale on a, map 5 by means of a pantographic apparatus, the displacement of the lines of the reproduction being effected by securing the map 5 to an adjustable slide 6 displaceable relatively to a scale 9. The pole 2 of the pantograph may also be adjustable by screws 13, 14 to obtain correct orientation. The slide 6 may be replaced by a turntable to obtain an oblique displacement while the original and reproduction remain parallel. In the form shown in Fig. 4, whereby straight or oblique displacement can be obtained, the recording stylus 2 is carried by an arm 19 provided with an opening in which a disc 24 formed with a diametrical slot 26 is mounted. The driving- stylus 1 is carried by a slide adjustable to a scale in the slot 26. Adjustment of the disc results in the adjustment of the direction of displacement, and movement of the slide in the slot 26 affects the reproduction ratio. In the modification shown in Fig. 5. the arm 19 is guided on a rod 20a at right-angles to itself, and the rod 20a is carried by a sleeve 20 movable on a rod 21 parallel to the arm 19. The disc 24 carries an arm 27 extending in the direction of the slot 26 and guided by means of a slot on a pivot. 28a mounted on an arm 20<b> on the sleeve 20. With this form, the axes of displacement of the reproductions are parallel to the arm 27. If the pivot 28a is positioned beyond the stylus 1 relative, to the reproductions, the. axes of displacement converge to a single point on the axis X-X. In order to allow for the diminution in the sine of the angle of observation, two toothed wheels 34, 35, corresponding in size with the ratio of the sines of the observation angles, are rotatable together on a common axis and engage respectively with teeth on the arm 27 and on a rod 33 adjustable on the slide carrying the stylus 1. As the stylus 1 moves over a contour line, the arm 27 actuates the wheel 34, and causes the displacement, through the wheel 35 and rod 33, of the slide carrying the stylus. This results in the movement of the arm 19 and the recording-stylus 2.. If the axis of wheels 34, 35 is at the point 28a on the arm 20<b>, displacement, corresponding to that shown in Fig. 5 is effected. The forms shown in Figs. 4, 5, and 9 can be combined with a pantographic apparatus for enlarging or reducing.