A New Plotting Instrument

1. A planar drawing device having an inner surface structure (4) and an outer structure (1) completely enclosing the inner surface structure (4), wherein the inner surface structure consists of a first material, characterized in that the outer structure (1) of the planar drawing device consists of a second material.

2. A planar drawing apparatus according to claim 1, wherein said inner surface structure (4) is made smaller in wall thickness than said outer structure (1).

3. Flat drawing device according to one of the preceding claims, wherein the inner surface structure (4) has a thickness of 1 to 3 mm, preferably 2 mm.

4. Flat drawing device according to claim 3, wherein the outer structure (1) at least in regions of 1 to 3 mm, preferably 1 mm, is made thicker than the inner surface structure.

5. Flat drawing device according to one of the preceding claims, wherein the outer structure (1) is dimensionally stable, in particular made of a metal material, preferably aluminum.Flat drawing device according to one of the preceding claims, wherein the inner surface structure (4) is made of a transparent material, preferably a plastic.

6. Flat drawing device according to one of the preceding claims, wherein the flat drawing device has the shape of an isosceles triangle.

7. Flat drawing device according to one of claims 1 to 7, wherein the flat drawing device is designed as a ruler.

8. Flat drawing device according to one of the preceding claims, wherein in the inner surface structure at least one geometric recess (7, 8, 10, 11) is arranged, wherein the geometric recess preferably represents a mathematical functions, in particular sections of the function graph f (x) = tan ( x) (7), f (x) = sin (x) (8), f (x) = x 2 (10), f (x) = 1 / x (11).

9. Flat drawing device, in particular according to one of the preceding claims, comprising an inner surface structure (4) and an inner surface structure completely enclosing the outer structure (1), wherein the two-dimensional drawing device comprises a locking device (3) for selective locking of the drawing device.

10. A planar drawing apparatus according to claim 10, wherein the locking device (3) comprises a locking pin (3c) which is mounted in a central position of the locking device (3) and can be locked in at least one retracted position and one extended position.

11. A sheet drawing apparatus according to claim 11, wherein the locking device (3) further comprises a return member (3d) for returning the lock pin (3c) from the extended position.

12. Flat drawing device according to one of claims 10 to 12, wherein the locking device (3) in the inner surface structure (4) or the outer structure (1) of the drawing device is embedded and a guide ring (3e) and in the guide ring movably slide-mounted locking button (3a ), which is formed in its center as a locking pin (3c), wherein the locking button (3a) is designed with a greater thickness than the inner surface structure (4) and the outer structure (1) such that it is both in the retracted as also protrudes in the extended position of the inner surface structure (4) or the outer structure (1) of the drawing device.

13. A planar drawing apparatus according to claim 13, wherein the guide ring (3e) is made of plastic.

14. A flat drawing apparatus according to any one of claims 11 to 14, wherein the locking device (3) comprises a flexible stop (3b) with a nose, such that the nose is first slightly deflected inwards when pressed down until it engages.

15. A sheet drawing apparatus according to any one of the preceding claims, wherein the guide ring (3e) forms a guide in the form of a track which defines the movement of the recess to the guide ring.

16. A planar drawing apparatus according to any one of the preceding claims, wherein the locking device (3) is arranged in a corner in the outer structure (1).

17. A sheet drawing apparatus according to any one of claims 1 to 11, wherein the locking device (3) is disposed in a central position in the outer structure (1).

18. Flat drawing device according to one of the preceding claims, wherein in the inner structure (4) at least one bore (9) spaced from the locking pin (3c) is provided and as a punctiform character element for drawing partial or full circles upon rotation of the drawing device to the locking pin ( 3c) is arranged.

19. Flat drawing device according to one of the preceding claims, wherein nubs (1a) are attached to the underside of the outer structure (1).

(Computer Translation from German original)