Patent GB-444638-A (GB)
Title: Photogrammetric plotting apparatus for multiple photographic cameras with an optico-mechanical device for stereoscopic observation
IPC: G01C11/00
Filed: 1934-09-24
Abstract: 444,638. Stereogrammetric apparatus. SANTONI, E., 89, Viale Cadorna, Florence, Italy. Sept. 24, 1934, No. 27425. Convention date, Sept. 28, 1933. [Class 97 (i)] In a photogrammetric plotting-apparatus using photographstaken in a multiple camera, each of a pair of photo - graph carrying systems can be turned about a point representing the view - point of the photograph to an angular position correspond. ing to that during exposure and an optical exploring member is mounted on a carriage displaceable in a plane parallel to the photograph and controlled through a spherical joint by a guide bar. The latter is universally pivoted at the view point through which the optical path of the exploration system also passes. The apparatus after being adjusted for a pair of photographs taken from different view points may be readily set for the other stereoscopic pairs taken by the multiple camera in the two exposures by turning the photograph carriers through the angle between the corresponding chambers of the multiple camera. The apparatus is composed of two symmetrical parts enabling two photographs to be observed stereoscopically from adjacent eyepieces 5, 5<1>. Fig. 1 shows the left-hand part. A point on the photograph 7 is observed by the optical path parsing from prism 28, via lenses 27, 29, prisms 11, 10, 8, 2, and 31, to eyepiece 5, the path from prism 8 to prism 2 being on the axis 1-1<1>, common to both parts and parallel to the plane of representation. The photograph 7 is mounted in an angular portion relative to the plane of representation corresponding to that during exposure, with the point 8 representing the view point. The photograph carrying system is supported by a frame 3 and carries along with it in its angular adjustments the axis 10-11 which is maintained perpendicular to the plane of the photograph. The axis 10-11 rotatably carries a perpendicular guideway 12-13 which carries lens 29 and prism 11 and along which runs a carriage carrying lens 27 and prism 28 and connected by a universal joint 15 to a pin 16. The latter slides in the sleeve 17 of a frame 18 pivoted at 22 in the sleeve 23 of a frame 24 pivoted in turn to the frame 3 at 25. The pin 16 and a coaxial guide bar 21 carried by the frame 18 are thus mounted for universal movement about the point 8, the distance from the plane of movement of the universal joint 15 to the point 8 being equal to the focal distance of the taking camera. The arrangement enables the prism 28 to be moved over the photograph 7 while the rod 21 materially represents the direction of the light which went to form the image at the point of the photograph observed. In order to prevent rotation of the image in the eyepiece due to relative movement between the various adjustable parts of the apparatus, an Amici prism 30 mounted in a rotatable ring carrying planet wheels 65 is arranged between the prisms 8 and 2. The planet wheels 65 are engaged by a bevel wheel 66 which may be manually adjusted to effect initial rectification and a bevel wheel 67 geared through bevel wheel 71 to bevel wheel 70. The latter is rotatably mounted in the tube 49 which carries the axis 10-11 and driven by a planet wheel 72 having its axis 77 carried by the tube 49 parallel to the axis 10-11. The planet wheel 72 is connected by an arm 74 to a link 75 terminating in a ball 100 which slides in a circular groove carried by the frame 24 and having its centre at the point 8. When the photograph 7 is parallel to the axis 1-1<1>, the ball 100 is in the centre of the groove 76 and the links 74, 75 are inoperative. When the tube 49 and photograph 7 are rotated to a position in which the plane of the photograph intersects the axis 1-1<1> at the point 1 (for example), the ball 100 is moved along the groove 76 to the position shown so that as the observation is changed from a point 9 to a point 101 (say), the planet wheel 72 and the image are rotated through an angle e viz. the angle 101-1-9. A collimation mark 32 is simultaneously rotated by planet wheel 72 in the contrary direction to the wheel 70. Lenses 33, 34 are provided to enable the light to pass through prism 30 as a parallel beam. The systems 34, 2, 31, 5 and 341 (not shown), 2<1>, 31<1>, 5<1> are each mounted on single supports which may be adjusted relatively to each other to vary the interpupillary distance. Fig. 2 shows in elevation an embodiment of the apparatus shown schematically in Fig. 1. The frame 59 carrying the photograph 7 is mounted on plate 96 which is pivoted on pin 92 but is prevented from rotating thereon by a pin 95 and hole engagement with the member 93 adjustable round pin 92 by tangential screw 94. The latter and the pin 92 are carried by the part 91 which is adjustabte by tangential screw 90 along a circular groove 88 in a part 87. The latter may be adjusted in turn by tangential screw 89 along a circular groove in the part 84 fixed to a pin 102. The pin 102 is rotatably mounted in the base frame 4, 6 and may be given slight adjustments by the integral arm 85 and screw 86. The arrangement permits the photograph to be placed with an inclination and orientation corresponding to the exposure position, the optical viewing parts arranging themselves in accordance with the position of the photograph and the Amici prism 30 being turned to eliminate rotation of the image in the eyepiece. If the apparatus has been adjusted for one photograph of a pair taken simultaneously in a multiple camera it may be adjusted for the other merely by withdrawing pin 95 and turning the photograph carrying part 96 on the pin 92 until a second hole is engaged by the pin 95. The two photographs are mounted on a plate which may be swung in its own plane to bring the appropriate photograph into the observation aperture. Fig. 8 shows a construction of the part 96 which enables four photographs taken simultaneously in a multiple camera to be easily set in correct position after the adjustment of parts 84-94 has been made for one of them. The part 96 may pivot on the pin 92 either at 107 or 106. In the former case the pin 95 co-operates with the holes I, II, and in the latter case with holes III, IV. The remote ends of the rods 21 slide in sleeves connected in known manner by universal joints and slides, adapted to be adjusted in accordance with the relative positions of the view points when the photographs were taken, to a carriage the movements of which in three direction, at right-angles enable a map to be plotted.