SU115220A2 - A device for building direct, converging at inaccessible points - Google Patents

Description

BASIC Auth. St. JY 109982 describes an instrument for constructing straight lines converging in destructive points, containing fixed lines and a cross-section viewfinder that slides over them.

The proposed device differs from the device by the author. No. 109982 in that it uses not two, but three guide lines, interconnected by two bows. Such an embodiment of the device makes it possible to double the working area for moving the ruler and simplify its adjustment.

The drawing shows a diagram of the proposed device. The instrument includes three articulated ruler lines, 2, and 5, attached fixedly to the drawing table, and one reticle. The latter consists of the actual ruler 4 with the sighting edges and the cross member 5 with acute-angled protrusions 6 sliding along the edges of the sharply connected rulers /, 2 and,.

The hinges connecting the rulers I, 2 and 3 consist of rotating plates fixed by the fixed wing 7 in the required position. The center of each joint is precisely aligned with the point of intersection of the working edges of the rulers I, 2, 3. On one plate there is a scale of 8 deletions of inaccessible vanishing points to the working edge 9 of the ruler 2; The other plate has a circular contoured edge 10 for applying pencil marks on it by hand. The proposed instrument is used as follows. In order to draw direct and and 12 through arbitrary points L and B, which are directed to the same vanishing point as the vanishing point of two reference straight lines 13 and 14, the rulers /, 2 and 5 are superimposed on the drawing and attached to the working edge 9 of the ruler 2, the sight line 4 so that its sharp-angled. The protrusions 6 are aligned with the centers of the hinges, and the sighting edge coincides with the straight 13. The ruler 4 is held in this position with the hand or secured to the drawing board MOM- ruler, pressing the acute protrusion 6 to the working edge 9 of ruler 2, and Dial Rotate line / long until sighting line 4 is not sovmestits edge of the second reference 14 forward.

Then, pressing the sighting line 4 with its acute-angled speakers 6 to the working edges of the 1 to 2 or 2 lines, and moving the sighting line 4 down or up to align its sighting edge with the given points L and alternately draw the desired 11 and 1 with a pencil 2 These lines will be with sufficient accuracy for practice ria directed to an inaccessible vanishing point defined by two reference lines 13 and 14.

By changing the angles between the articulatedly connected rulers I, 2, 3, the device can be tuned to various inaccessible points.

A device for building direct, converging at inaccessible points, by author. (ST. No. 109982, characterized in that, in order to simplify the setup of the device, expand the range of its operation from one setting and enable the alternate drawing of straight lines converging at two or more points, it uses a third guide bar, hingedly zan11a with one of the guides.