Patent GB-191128229-A (GB)
Title: Improvements in Arrangements for Copying in Space or in a Plane an Object of Three Dimensions from a Stereoscopic Pair of Photograms.
IPC: G03F7/00
Filed: 1911-12-15
Granted: 1912-09-26
Abstract: 28,229. Zeiss, C., [Firm of]. Dec. 19, 1910, [Convention date]. Photographic surveying-instruments.-In an arrangement for copying from a stereoscopic pair of photograms, the surface of an object of three dimensions, or linear or punctual elements of this surface spatially or on a plane surface, an actuating system to be manipulated by the copyist acts on a comparator system to bring the corresponding images of any point shown in the photograms into apparent coincidence with the mark, and also acts on a copying system so that the position of a tool point with respect to a copy-carrier corresponds to the position of the observed piont in the photograms. The comparator comprises three slides A, B, C; the slide A causes a relative displacement of the microscope and photograms in the ' height direction,' the slide B causes an alteration in the ' breadth direction,' and the slide C acts on the distance between the photograms, the mark changing its position relatively to the landscape in the ' depth direction.' The apparatus shown in Figs. 1, 2, and 4 comprises a ' blink ' microscope a for examining the photograms e. The blink microscope is carried upon a slide A moving in the ' height direction ' of the photograms, which are mounted in slides B, BC so as to be displaceable together in the breadth direction, the slide BC being also independently movable so as to act upon the distance between the photograms and thus representing the slide C. The copying-system has the ' breadth slide ' B' arranged at the lowest one, and the height slide A', to which the tool f can be attached, as the top one. Actuating-handles g are fitted on the slide A'. The slides B, BC of the comparator system are coupled with the depth slide C' of the copying-system and thus indirectly with the breadth slide B' by two-armed levers i, k pivoted on axes i<0>, k<0> so that to a joint displacement of the slides B, BC without relative displacement there corresponds a displacement of the breadth slide B'. In order that a movement of the depth slide C' may be produced by an alteration of the distance between the slides B, BC, the distance o, p is made shorter than the distance i<0>, k<0>. The comparator slide A is coupled to the copying-apparatus height slide A' by a right-angled lever q<1>, q<2>, of which the pivot lies in the plane i<0>, k<0> in a universal joint r, s. The arm q' is slidable in the inner part s and is rotatable about the driver t of the slide A. The arm q<2> is rigidly connected with the inner part s of the joint r, s and is slidable in the inner part u of a universal joint u, v mounted on the slide A<1> in the plane o, p. Each of the slides of the copying-device is furnished with a clamping-screw w. For copying lines of height, the height slide A<1> is fixed, and similarly for lines of breadth and depth. Other sequences and couplings of the slides than those shown are possible. With the slide A no lower slide than the upper one of the two slides A<1>, C<1> may be coupled, with the slide B no lower slide than the upper one of the slides B<1>, C<1>, and with the slide C, when the slide B moves the microscope, no lower slide than the slide C', and when the slide B moves the photograms, no lower slide than the upper one of the slides C' and B'. In an arrangement for copying only lines of depth, a coupling between the slides C, C<1> is dispensed with, the slide B being arranged either to displace the micrscope or to carry not only the left-hand photogram but also the slide C with the right-hand photogram; the doublelever k may thus be dispensed with if slides C, C<1> are fitted with scales for setting their positions. When the lines of depth are copied only on one and the same plane surface of the copycarrier, the slide C<1> also is dispensed with. When using the cross-slide device, the sequence shown becomes inapplicable. The depth slide C<1> is then chosen for the bottom member, and the height slide A<1> and breadth slide B<1> may be disposed on it, one fitted with the tool and the other with the copy-carrier, or the slides A', B' can be fitted the one on the other, the upper one carrying the tool while the copy-carrier is mounted on the depth slide C'. When only lines of height or of breadth are to be copied on a single plane surface of the copy-carrier, the cross-slide member with the sequence shown in Figs. 1, 2, and 4 can be retained; for lines of height, the tool may be mounted on the depth slide C<1>; for copying lines of breadth, the copycarrier mav be mounted on the breadth slide B'. This result may be obtained more simply with the depth slide C<1> as bottom member by disposing the slides A<1>, B<1> on the slide C' next to each other and mounting the tool on the slide B<1> or A<1> according as lines of height or breadth are required. The slide A may then be coupled with the slides A', C' more simply than shown in Figs. 1, 2, and 4 by means like those used for coupling the slide to slides B', C'. The height of the arrangement may be reduced by mounting the height slide A' in the breadth direction. An example for copying lines of height of a drawing-surface is shown in plan in Fig. 5. The binocular microscope a is mounted on a fixed standard a<1>, and the slide A carries the double slide B, BC with the two photograms e. The drivers m, n are connected to the slides B, BC by the pins and slide-ways shown. The slide A is coupled with the slides A', C' by a bell-crank lever q<0> and a two-armed lever q. The breadth slide B<1> is fitted with the drawing- style f<0>. In order to be able to change the length of base line used, or the scale of reduction, or both, the driver p for the lever k is mounted on an adjustable slide p. The breadth slide B<1> and the depth slide C<1> are moved by means of the screw-spindles x, v respectively actuated from the hand-wheel shafts x<4>, y<7>. When the arrangement is to be used for the plotting and tracing of any points and lines in the landscape, the slide A' is fitted with an actuating-device, which may be driven by the foot. The set-screw w is then superfluous.