CUTTING PLIERS Russian patent published in 2001 - IPC

FIELD: medical engineering. SUBSTANCE: device has two pivotally connected branches with upper and lower disk-shaped jaws mounted in parallel planes. Each jaw has through holes and grooves corresponding to wire, having the same size and mirror symmetric relative to separation plane of the instrument with respect to holes and groove on the other jaw. The holes are arranged in a way that their axes are in parallel relation to the central axis and the grooves are radially directed with respect to the central axis. All holes and grooves have cutting edges on contacting surfaces of the upper and lower jaws circumferentially and along the internal contour, respectively. Branches and jaws are rotatably mounted in separation plane of the instrument with simultaneous synchronization of axes of the holes and grooves corresponding each other in size and position on the upper and lower jaw and have unit for simultaneous synchronizing axes of the holes and grooves corresponding each other in size and position on the upper and lower jaw. The unit has cam connection in the zone of matching of the upper and lower jaw, notches on matching surfaces of the upper and lower jaw forming curved surfaces in the plane disposed vertically relative to the separation plane of the instrument. The curved surfaces have concave and flat portion on the upper jaw and convex and flat portion on the lower jaw. The radii of the concave and convex portions on the surfaces are equal to each other and are 2.5 times as large as wire hole diameter. Their centers are displaced relative to each other in vertical direction in parallel to the central axis at a distance equal to 0.425 times diameter of wire hole. Working part length of matching zone is equal to 0.2 times diameter of wire hole. EFFECT: enhanced accuracy in positioning the real place of biting; reduced risk of traumatic injuries of soft tissues. 11 cl, 7 dwg