BRAIDED SAFETY CORD OF THRESHOLD OPERATION Russian patent published in 2010 - IPC D07B1/00 

FIELD: textile, paper.

SUBSTANCE: safety braided cord of threshold operation comprises a core, made of bundle of rectilinearly arranged threads, around which there are at least three layers of braiding arranged coaxially one in the other shaped in the form of thread-like body of tubular shape, formed by braiding of even number of braiding threads separated into two equal parts, in every of which threads are arranged along spirals of the right and left directions. External layer of braiding is bearing, and inner layer and core made of equal quantity of textile threads identical in raw material composition and linear density, serve as energy-absorbing elements ruptured under action of threshold load. At the same time angle of inclination of braiding threads in each layer to longitudinal axis of cord is determined by the following equation: α_m= 15 + 30[(m-1)/(n-1)], where: α_m - angle of inclination of braiding threads to longitudinal axis of cord in degrees; m - serial number of braiding layer, starting from the inner one; n - common number of braiding layers. And threshold of operation is determined by the following formula: P_op = P₁[1 + 0.75(n - 1)], where P_op - threshold of operation in kgf; P₁ - total rupture load of core threads in kgf; n - integer number of braiding layers in cord. At the same time total rupture load of braiding threads of external layer at least 10 times exceeds value of cord threshold operation.

EFFECT: in case of emergency actuation, invention provides buffering and suppression of impact load due to conversion of kinetic energy of falling secured body into operation of braided layers textile threads rupture.

3 dwg, 1 tbl