GB785054A - An improved device for measuring distance along a line on a map, or the like - Google Patents

Abstract

785,054. Counting apparatus; map measures. TIDAK, Ltd. Feb. 10, 1956 [Feb. 11, 1955; May 11, 1955], Nos. 4185/55 and 13687/55. Classes 106 (1) and 106 (2). A map measurer comprises a series of drums 10, Fig. 2, enclosed end-to-end in a rigid holder 1 in one end of which is journalled a mapengaging wheel 4, a drive 6, 7, 9, 13 between the wheel 4 and the adjacent drum and lostmotion connections between pairs of adjacent drums whereby the second drum of a pair is picked up and rotated by the first only after a predetermined angle of rotation of the first drum, each drum bearing on its cylindrical surface a scale or mark to register with and visible through a window 28 in the holder 1. In the embodiment shown in Fig. 2, each drum has a narrow short projection 12, Fig. 3, extending in the axial direction from its end for transmitting the drive to the next drum, interengagement occurring as the driving drum reaches its angular position of maximum indication while the driven drum is still in its zero position. Similar means 12 may be provided for engaging the first drum and the wheeldriven gear 13. In this form the distance is given by the highest order drum not registering zero. In the embodiment shown in Fig. 6, a transfer element 32 is provided between each pair of drums, engageable by a single projection 12a, or a leaf-spring 40, Fig. 9, on the lower drum at each revolution thereof, to rotate, by means of its engagement with a plurality of projections 12, the next upper drum the whole series of drums acting as a decimal counter. Resetting may be performed by axial and rotational movement of a knob 16, Fig. 2, so that a projection 22 thereon drivingly engages a rod 25 secured to the pinion 13 whereby the series of drums may be driven in reverse to zero, or the rod 25 may have driving engagements with each of the drums. In another embodiment the indication of distance is given by the intersection of helices on the drum with a graduated scale carried in or on lateral apertures in the holder.