COMBINATION TYPE SHEARS Russian patent published in 2007 - IPC B23D17/06 B23D29/00 

FIELD: plastic working of metals, possibly cutting sheet, shaped and rod materials.

SUBSTANCE: combination type shears include hydraulic cylinder with control unit; two levers having cutters with cutting edges and mounted with possibility of rotation one towards other in common axle. Cutting edges have cutting teeth. Fixing teeth are formed on outer surface of lever ends. Length of cutting edges consists at least of 0.6 of level length. Cutting edges are tapered one to other by angle 40 - 50° relative to cutting line. Cutting teeth have pitch Z = 5 - 8 mm, thickness l1 = (0.2 - 0.25)Z, height h = (0.25 - 035)Z and width of initial land l = 0.8 -1.0 mm. Each tooth is tapered by angle α = 60 - 80° to side of lever rotation axis and it is sharpened by angle β = 25 - 35°. Fixing teeth have pitch 3 - 5 mm, depth 1.0 - 3.0 mm and inclination angle 60 - 80° to side of lever rotation axis. In variant levers end portions are tapered on their outer surface along length of 4 - 10 teeth by angle α₁ = 20 - 40°. On inner surface of levers before cutting teeth smooth supporting surface with width 20 - 40 mm is formed.

EFFECT: enhanced efficiency of cutting and drawing apart due to using optimal non-symmetrical configuration of cutting and drawing apart fixing teeth.

2 cl, 4 dwg