SU112040A1 - A device for automatically drawing axonometric projections of an image along its orthogonal projections - Google Patents

Description

The known devices for drawing axonometric projections are not adapted to automatically perform their functions.

The proposed device solves the problem of automatically drawing projections by using the well-known principle of making a photograph of a pegraph — rotating cylinders and moving along them on the spindle of a lifting device with a photocell and a food device.

A distinctive feature of the proposed device is that, in order to change the angle of the axonometry, the cylinders are rotated asynchronously, and the removing and writing devices move at different speeds, and the speeds of rotation of the cylinders and the movements of the lifting and feeding devices can be adjusted using a speed box.

FIG. 1 shows a schematic diagram of the construction of axonometric projections of a flat figure; in fig. 2 - schematic diagram of the device.

The method of constructing axonometric projections of an image from its orthogonal projections in this device is based on the removal of the contour of the original projections and the sequential construction of axonometric projections.

FIG. Figure 1 at the top right gives an image of a circle in the original orthogonal projections. Affinity is given by the axis of kinship and the direction of kinship connecting the O and Oo points. Through point O, a straight line parallel to the Y axis is carried out before intersecting at the point h with the axis of kinship. Point / g and Oo are connected by a straight line, which is the corresponding line Oh. In the original image, parallel to the kinship axis, a chord is drawn to obtain points a, b, c. To construct these points in the affine image, the lines ag, bl, ck and the corresponding Aug, Boi, CQ / C lines are drawn. AQ points

No. 112040-2 -

The ya and co are intersected by the lines / 1аа, Bab and Soi with the lines drawn before that parallel to the lines O (N.) The resulting triangles Agag, VdY, Cgck are identical, since their respective sides are equal and parallel.

The direct vertices connecting them are mutually parallel, and the corresponding segments of these direct ones are equal. Since one of these direct axes is a relationship axis, it follows that the affine image of any direct parallel axis of relationship is parallel to this right my. Therefore, the wire on the original image of any apr. Om. Def, we obtain in the affine image a line parallel to and equal to the line df. In this case, the distance between the parallel lines L, in the original projection, is converted into the distance L in the affine image, and the magnitude of the change in this distance depends on the angle of the axonometry between the axes Xa and Wo.

It is also known that a cylindrical screw of a constant pitch is unfolded and the plane into parallel straight lines that are located at equal distances from one another. Therefore, to remove the original image in a series of parallel straight lines, it is enough to reinforce a sheet of paper with an ethn.m image on the cylinder surface, apply a continuous constant pitch helix to it and mark its intersection points with the image lines. The transformation of the resulting straight grid is carried out according to the same helix principle with pitch change.

The device is based on the above positions. The initial projection and traced axonometry are located on the surface of two cylinders - the transfer cylinder / and the recording cylinder 2. Both cylinders rotate in the same direction. Along the surface of the transfer cylinder / moves parallel to its axis when the lead screw 3 is removed, the removal device 4 equipped with a photocell, and the writing device 6 moves along the surface of the recording cylinder 2 parallel to its axis on the lead screw 5 helix.

The speed of rotation of the cylinder / and the movement of the removal device 4 is constant; The speed of rotation of cylinder 2 and the movement of writing device 6 are also constant, but for each type of axiometry they differ from the speeds of the transmitting cylinder / and removal device 4. Due to the difference in speeds, the angle of axonometry is varied. The rotational speeds of the cylinder 2 and the movement of the writing device 6 of the head are varied by means of a speed box 7 equipped with appropriate scales and indicators. Amplifier 8 is applied to amplify the electrical impulse from the photocell. The device is driven from the electric motor 9 using rectifiers JO.

Subject invention

A device for automatically drawing axonometric projections of an image along its orthogonal projections using rotating cylinders and moving along them on the chassis of a photocell pickup device and a writing device, in order to realize the possibility of measurability; angle views, the cylinders rotate asynchronously, and the lifting and writing devices move at different speeds, and the speeds of rotation of the cylinders and the movements of the lifting and feeding device can be adjusted using the gearbox.

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