GB897901A - Improvements in or relating to photogrammetric restitution machines - Google Patents

Abstract

897,901. Photogrammetric apparatus. NISTRI, U. Dec. 16, 1958 [Dec. 19, 1957], No. 40585/58. Class 97(1). A photogrammetric plotting apparatus for profile tracing has a double optical projection system, and a movable screen mounted on a support, the support being constrained to move along a straight line lying in a plane corresponding to the horizon plane of the optical model, which line is orientable at will in the said plane. The two plates to be traced, 1, 2, are illuminated by lamps 3, 4, and the homologous rays 9, 10 meet at a point II, a mark on the movable screen 12 being brought into coincidence with this point. The screen is mounted on a bracket 13 and can be moved vertically by a screw 14, which is rotated through a gear train operated from a knob 18. Rotation of screw 14 also moves, through a further gear train, a rack 22, which is constrained to move along its own axis, and carries at one end a pencil 24. The gear ratios are such that the movement of the pencil is that of screen 12 multiplied by a given constant, which can be changed by altering the gear ratio. The apparatus is built on a main support 15 having rollers 27. The support 15 rests on a table, and is constrained to move along a particular straight line in the plane of the table by a guide bar 29, which is at right angles to the rack 22. The guide bar can be made to assume any required position in the plane of the table.