ROLLED SHEET SHEARS Russian patent published in 2009 - IPC B23D15/02 B23D15/06 B26D5/08 

FIELD: mechanics.

SUBSTANCE: proposed shears comprises lower knife and movable upper knife interacting with the former and furnished with cutting edge formed by circular arc and articulated with the driving lever link and head arranged to move in vertical guides of the fixed base. The movable lower knife is articulated with the knife head that moves in vertical guides and with the driving lever link on the side opposite to its axis of rotation. The cutting edges of both knives are formed by circular arcs, the upper knife cutting edge centre of curvature, on the side of driving lever link, being located on the continuation of axis that passes through the hinge of the driving lever link and hinge. The centre of curvature of the cutting edge of lower movable knife, on the side of the knife head linked up with it, is located on the continuation of axis that passes through the hinge jointing the lower movable knife with its head and driving lever link together. The radii of circular arcs that form the cutting edges of both knives are selected proceeding from the condition of their identity required to allow a permanent overlapping of the shears knives in compliance with the enclosed computation formulae.

EFFECT: increased cutting angle, permanent overlapping.

1 dwg