Patent GB-200198-A (GB)
Title: New or improved means for mechanically reproducing portraits, figures, models or the like in the round, in relief, or in intaglio from stereoscopic photographs
IPC: G03F7/00
Filed: 1922-04-07
Abstract: 200,198. Townsend, E. E. April 7, 1922. Milling - machines. - Apparatus for reproducing a copy in relief or intaglio of a threedimensional figure from a pair of stereoscopic photographs of the figure in which the detail in one photograph is utilized to control the movements of the cutting tool of a carving machine in the two dimensions of length and breadth whilst the variations between the two photographs are utilized to control the movements of the cutting tool in the third dimension of depth, comprises a carrier for the photographs and the material to be carved, a gauge for following variations between the photographs, a carving tool coupled to one end of the gauge for movement in two dimensions, and a variable and adjustable coupling between the tool and tha other end of the gauge for movements of the tool m the third dimension. Two photographs w<1>, w and the work w<2> are supported on a table a. A carriage b movable along guides a<1> by means of a screw a<2> and hand-wheel a<3> carries a saddle c movable transversely along guides b<2> on the carriage b by means of a screw b<3> and handwheel b<4>. On the saddle are mounted a cutting tool f, a fixed tracer c<1> and a movable tracer c<2>. The latter is carried by a block c<3> slidable in transverse guides c<4> on the saddle c and has a pin c<8> engaging a slot g<1> in a lever g, which fulcrums about a pin g<2> and is pivoted at g<3> to a nut d<2> traversable by a screw d and hand-wheel d'. Trunnions d<3> on the nut d<2> are connected by links e<1> to bell-crank levers e the other arms of which are connected by links e<2> to the post f of the cutting tool f<1>. The tracer c' is caused by manipulation of the handwheels a<3>, b<4> to traverse an image line &c. of the photograph w', thereby causing the cutter f<1> to perform like movements in a horizontal plane, and at the same time the tracer c<2> is caused by manipulation of the hand-wheel d<1> to traverse the corresponding image line &c. of the other photograph w, tha relative movements between the two tracers due to the stereoscopic variations being converted by the bell-crank lever &c. connections into up and down movements of the cutter. The ratio of these up and down movements of the cutter to the variation distances may be altered by moving the fulcrum pin g<2> of the lever g along the slot c'. In order to provide sufficient lines &c. on the photographs to enable the machine to be more easily operated, such lines &c. may be produced by projecting on the object at the time of photographing the image of a lined screen through an optical lantern. In the modification shown in Fig. 4, the relative movement between the tracers c<1>, c<2> causes rotation by means of a rack c<15> and pinion c<14> of a shaft c<12> which is geared by pinons c<17>, c<16>, or by belting, to a shaft c<10> having a pinion c<9> gearing with a rack f<2> in the post f of the cutter. The shaft c<10> carries a worm wheel c<18> engaged by a worm d<4> on the spindle d of the hand wheel d<1>. By changing the gears c's, c<17> the ratio of the vertical movements of the cutting tool may be varied. Specification 23626/12, [Class 98 (ii), Photographic processes &c.], is referred to.