SU10257A1 - Compasses for drawing spirals - Google Patents

Description

The present invention relates to compasses for drawing spirals by continuously increasing or decreasing the distance between the legs, compasses,

On. the drawing of FIG. 1 depicts a front view of the proposed compasses; FIG. 2-side view; FIG. 3-part nut; FIG. 4-axis axis cal.

The proposed compass consists of spring-apart legs and legs, provided with longitudinal cuts k with transverse semicircular grooves h at the edges, in which the trunnions g located on the nuts "located on the g screw with left and right threads, bearing in its middle part bevel gear s in engagement with bevel gear e mounted on the end of the roller passing through the hole t of the axis o and the head b of the compass attached to the spring a and carrying the end of the head d.

When drawing a spiral, the head of d is pressed with the index finger, and the head b is turned by the thumb and middle fingers; thus, the curve is obtained with increasing or decreasing radius. To increase or decrease the pitch of the helix, the nuts and screw T are moved from one notch to another.

The subject of the patent.

A compass for sketching spirals, characterized in that in its legs, moved apart by spring a, there are longitudinal slits k with transverse semicircular grooves h on the edges, in which pins g of nuts n are screwed onto the screw having a right and left thread screw with a bevel gear j in the middle, coupled with gear e at the end of the roller c, passing through the head b of the compasses and terminating in the head {

FIG. I

FIG. 2

h

FIG. sz

-3

FIG. four