SU55799A1 - Perspective Drawing Device - Google Patents

Description

Instruments for building perspectives are known, consisting of two pivotally connected rulers, which form a hinged parallelogram with two short rulers, fixed by one of its vertices on a ruler, and with a hinge in the opposite vertex movable in the slot of this ruler.

Also known are devices consisting of two pivotally connected rulers, reinforced with their hinge on the third ruler and missed into clips, fastened on the table so that the rulers form the required angle.

From all such devices, the proposed device for perspective drawing is different in that although it is also made in the form of two articulated guide lines, reinforced with its hinge on the drawing ruler and intended to move along the guide pins mounted on the table, it has the peculiarity that for rigid installation of rulers at the required angle to each other, the guide bars are provided with angular processes superimposed one upon the other and provided with slots for a common stop wine one attached to the sector that serves as the holder of the drawing ruler.

In addition, for mounting the guide pin, if necessary, a special holder attached to the table is provided outside the table.

In FIG. 1 shows a schematic diagram of the geometrical justification of the device; FIG. 2- the whole device in axonometric form; FIG. 3-holder for mounting a guide pin outside the drawing table with a separately illustrated screw for controlling it; FIG. 4-geometrical scheme of such a case.

The theoretical justification of the device is the theorem that “through three points you can always draw a circle, and moreover only one.

Assume that the perspective drawing has the form ABE-fCD (Fig. 1). Continuing the lines AB and DC until they cross at point I and line B and CT until they cross at point F, we obtain the line FI-F.2, which is the horizon line. Then an arbitrary radius R from a point.

lying on the horizon FiF ,,, draw a circle through point F so that it partially (as indicated in Fig. 1) passes within drawing 1, 2, 3, 4 and intersects the horizon at some point L, and restores perpendicular to both sides to the horizon line at an arbitrary distance between point M and line drawing /, 2. Get the intersection point of the circle with the restored perpendicular Fy-F.

Connect the point M of direct with and F, we obtain the angle a. Let's measure this angle and for example let's take it equal to 10 °.

If we now turn to the device (Fig. 2), then from the drawing it can be seen that the studs 7, which are stuck into the plane of the drawing, are nothing more than points F .; and F (Fig. 1); arc-shaped goniometric shoots of 7 and 2- parts of a circle, JO lamb with a screw - point M; nut 8 on the screw-center About circumference; the rulers are from the center 8 to the 7-radius OF and OF studs and the 9-line ruler passing through the points O, M and F (Fig. 1).

If we now rotate the OF., F sector in the drawing so that the point M moves in a clockwise or reverse direction, and imagines the point F fixed regardless of the circle, then the straight FiM and its extension to the right will change its position, for example F AB to. Thus, point f will serve as a vanishing point.

To accomplish this, it is necessary first of all to set the goniometric rulers on the device so that they form angles a with the line F., F.

For this, on sector 3, constituting a continuation of the ruler 9, with which it is fastened with screws with nuts, there is a zero stroke, relative to which the arcs of the projection lines ruler are shifted by an angle y.

Practically for this, a small perspective drawing is drawn, a circle is drawn, lines F.F and the value of the segments NF .. and NF and the angle y are measured.

Then, after drawing the horizon line in the final drawing and setting aside the distances NF.,; and, perpendicular to the scaled attitude, setting the angle of the device on the device, turning the goniometric rulers, using the scales applied on their arcuate processes / and 2 and degree scales, apply the device to the studs of the 7 angles of the measuring lines and rotate the ruler 9 so so that the goniometric rulers slide along the pins 7. At the same time, the ruler 9 will give the direction of the lines converging always at the same vanishing point F ,, as required when constructing the perspective.

Often it is necessary to have a perspective from purely artistic considerations close to the bottom edge of the board (line /, 4, fig. 4) therefore the point falls beyond the edge of /, 4. But since it is impossible to do without point F, a holder is provided for this (Fig. 3 ), which is attached to the edge of the board /, 4, and a pin 6 at the point G is already put on it. The holder is fixed to the table with a screw 5.

In order for the prospect to be built as you please, i.e., so that its main facade narrows to the left, and also, it is necessary, and to the right, you need to turn the ruler up to 180, remove the screws and rearrange the angular guides Scales with a bullet line that is printed on both sides of the device. Further work is done in the same way as described by you Hie.

The subject matter of the invention.

Claims (2)

1. A device for perspective drawing, made in the form of two ni- pairedly connected guide lines, reinforced with its hinge on a drawing ruler and intended for movement along guide pins mounted on a table, characterized in that for rigid installation of lines at a desired angle to each other , guides rulers are equipped with arc-shaped goniometric processes. superimposed one on the other and provided with slots for a common locking screw attached to the sector that serves as the holder of the drawing ruler. 2. When using the device according to claim 1, use the holder attached to the table for the guide pin, if necessary, to install it outside the table. figure 1 -Oi iO D a and s HP (r ;. O) pq OH -. 35 -H Kp  f - (CD fcC Oh oh n m sz