Patent GB-432546-A (GB)
Title: Improved map-holder and method of following an itinerary over a map
IPC: G09B29/06
Filed: 1933-10-27
Abstract: 432,546. Maps. DUCOMMUN, E. H. C., 13, Rue de Verdun, Versailles, France. Oct. 27, 1933, No. 29890. Void [Abridged as open to inspection under Sect. 91 of the Acts, May 3, 1934]. [Class 146 (ii)] A map holder comprises a frame having two pairs of independently rotatable rollers, each pair of which supports a strip map, formed as described below, the strip maps being mounted side by side and parallel so that both are exposed simultaneously at the reading aperture in the frame. The two pairs of rollers a<1>, a<3> and a<2>, a<4>, Fig. 1, are mounted as shown and each map strip passes from one roller of a pair to the other over guide rollers g<1>, g<2>, and is independently operated by crank handles &c. gearing with pinions provided on the rollers. The horizontal parts of the bands travel over a fixed table h, Fig. 3, thereby rendering possible the recording of data upon the bands, and a transparent protecting screen i, removable by sliding, is provided. A flexible screen k, carried by a spring roller j, bears on a reduced scale the maps carried by the rollers, and illuminating lamps l may be provided either inside or outside the casing. The sheet i carries a circular scale graduated in degrees and is provided at its centre with a rotatable pin m which is connected to a transparent disc bearing parallel and equidistant lines graduated in centimetres and also a line perpendicular thereto and passing through the pin m<1> ; these lines serve to measure distances and also indicate the direction of travel and the geographical angle of the course. A door n is provided and if desired the two adjacent rollers may be locked together to form a single roller by means of a key o or other device, while the partition p is removable. The map strips are formed by assembling together the maps, which may be to different scales, and dividing them into rectangles by horizontal and vertical lines. Each rectangle is suitably marked, A<1>, A2, A3 &c. being used for a horizontal and A<1>, B<1>, C<1> &c. for a vertical row, and these markings are reproduced on the key map provided on the screen k. The map is cut into vertical strips all of which are united to form a band and this forms one strip, which is mounted between one pair of rollers. The second strip is identical with the first strip, and by using in each strip portions drawn to different scales it is possible to examine for example, a small scale part on the left strip and a large scale detail on the right strip. When adjacent rollers are to be coupled together, the map strips are formed by dividing two identical maps by vertical and horizontal lines, but the vertical lines in one map are displaced relatively to those in the second map and alternate vertical widths in each are made narrow. The map strip is formed by uniting into a band lengths taken alternately from the two maps, each individual length containing on the left and right sides the same map details as the right and left sides respectively of the lengths immediately preceding and following it. The total width of the band is also equal to the combined length of two adjacent rollers.