A detachable flyer bow system, apparatus and methods of using the same are provided. The systems each comprise a base having a longitudinal recess with an inner lateral dimension that is greater than the outer lateral dimension and a front lateral dimension that is smaller than the rear lateral dimension, an end block attachable to the end of the flyer bow with a recess engagement portion to slidably engage the longitudinal recess of the base. The end block may cooperatively wedge within the base and its cross section may have a dovetail shape. The base may have an opening to allow at least a portion of the end block to clear the opening for the inward insertion of the end block into the base, or the outward removal of the end block from the base. The opening may be located between the front side and the back side of the base. Methods for securing a flyer bow to a wire twisting machine, methods of attaching a flyer bow to an end block, and flyer bows in combination with end blocks are also provided.

A steel cord and a manufacturing process are disclosed. The steel cord includes a steel core wire located in the center and having a diameter of d; and M sheath-layer steel wires arranged around the steel core wire in the center, tangent to the steel core wire, and having a diameter of d1, at least two gaps L existing between the M sheath-layer steel wires, where M is 4; d, d1, and L satisfy the following relationship: 0.420<(d/d1)<0.800, d1 is between 0.20 mm and 0.44 mm, and L0.0008 mm. The steel cord of the present invention may allow rubber to be fully penetrated into the gaps, thereby reducing air content in the steel cord, avoiding point contact friction between the layers of steel wires due to insufficient rubber penetration, and further solving the problem of failure of the bearing capacity of the steel cord due to abrasion.