GB191102492A - Process and Apparatus for the Plastic Reproduction of Objects. - Google Patents

Abstract

2492. Selke, W. Jan. 31, 1910, [Convention date]. [Addition to 29,260/10.] Artistic modelling.-Relates to modifications of the methods described in the parent Specification for the reproduction of solid objects by means of photogrammetric and stereogrammetric theodolitic photographs. In one modification, the stereogrammetric plates 2, 3, Fig. 1, are located in parallel planes, and are observed in a Wheatstone's mirror stereoscope, the prism surfaces 24, 25 of which are only slightly silvered and therefore transparent. A workpiece is modelled from the virtual image seen by a pantograph 29 journaled in a ball joint 28 and carrying a style 31, which determines the particular point of the work-piece 21 corresponding to the point indicated by a tracer 30 on the virtual image 26. In another method, the mirror-stereoscope is fitted with enlarging- oculars 32, Fig. 2. The stereo-plates 2, 3 are displaced horizontally and vertically in their own planes. A rod 9, which is mounted on the suspension 7 and positively connected with the plate 3, gives the direction in space of a selected image point. The depth of the observed virtual image is diminished proportionately to the magnification of the oculars 32 and accordingly has for example a depth 34<a> to 34<b>. This depth is proportionately re-magnified by the rod 35 which moves a rack 41 according to the movement of the tracer point 34. The rack 41 operates gearing 37 to move correspondingly the sighting-tube 19, which gives the required point on the work-piece by sighting the rod 9. Reproductions on different scales are made by varying the positions of the suspensions 7 and of the rack 41. A modification of the latter method is also described in which the plates 2, 3 are situated in the same plane. Alternately again, instead of mechanical means for correcting the deformation of the depth of the virtual image due to the ocular enlargement, a binocular prism telescope 38, Fig. 4, is arranged in front of the mirror-stereoscope. The distance B between the objectives is enlarged to the distance between the objectives of the taking- cameras. By this means the point of a working- tool 9 is readily brought into apparent contact with the point P on the surface of the virtual image and obtained on the work-piece 42. The instrument 24, 38 is vertically displaceable parallel to the plane of the plates 2, 3. Reproductions on a changed scale are made by enlarging or reducing the plates 2, 3 and proportionately enlarging or reducing the distance B. The Specification as open to inspection under Section 91 (3) (a) comprises also a method of locating any point P on the work-piece, which consists in obtaining two directions in space from two photogrammetric negatives. This subject-matter does not appear in the Specification as accepted but forms the subject of the divided Application 1747/12.