Apparatus for producing axonometric drawings from orthometric drawings

摘要

741,554. Perspective drawing-instruments. PESARINI, T. Oct. 2, 1953 [Oct. 2, 1952], No. 24710/52. Class 97 (3). Apparatus for producing axonometric drawings from orthometric drawings comprises a board 1 for the orthometric drawings with a beam 3 movable thereon along the axis of abscissse parallel to the axis of ordinates and a tracing point 4 movable along the beam 3, a board 2 on which the axonometric drawings are to be produced with a beam 10 movable thereon along the axis of abscissµ parallel to the axis of ordinates and a drawing point 11 movable along the beam 10, means for transmitting the movement of beam 3 and tracing point 4 to the beam 10 and drawing point 11 in any. desired ratio, and means for moving the paper on which axonometric drawings are to be made relative to the beam and drawing point. The beams 3, 10 are caused to move parallel to the axis of ordinates by wires passing round pulleys 6, 61, 6SP11/SP, 6SP111/SP and 12, 12SP1/SP, 12SP11/SP, 12SP111/SP under boards 1, 2 respectively. Tracing point 4 and drawing point 11 are respectively mounted on slides 31, 101 movable along beams 3, 10 and connected to wires 7, 13 sliding inside sleeves 9, 91 and g, gSP1/SP connected at their ends to the beams and to a gear-box 5 mounted on board 1. Wires 7, 13 pass round pulleys 8, 14 respectively in gear-box 5, and the pulleys are connected by gears of a ratio giving the required enlargement or reduction. The pulley 6 is connected to a flexible shaft 17 driving pulley 12 through two sets of gears, the ratio of one set being the ratio of enlargement, and the ratio of the other set being the cosine of the angle of the axonometric view. Thus by varying the gear ratios the scale and angle of view can be altered. When passing from one part of the drawing representing one plane to another part representing another plane, the paper is displaced by a distance corresponding to the distance between the planes. To this end the paper is fixed to an endless flexible band 20 passing round rollers 18, 19. Roller 18 is rotatable by means of a flexible shaft s and a hand wheel 21, the amount of displacement being indicated by a pointer 22 on a scale 23. In modifications, the gearing may be simplified or replaced by pulley arrangements, and the board 2 may be slidably displaced on rollers or the like.