A cord (50) comprises a single layer (52) made up of N helically wound metal filamentary elements (54) having an outer diameter D, the metal filamentary elements (54) defining an internal enclosure (58) of the cord of diameter Dv. Each metal filamentary element (54) has a diameter Df and a helix radius of curvature Rf. With this cord (50), D, Dv, Df and Rf being expressed in millimeters: 0.10≤Jr≤0.25, 9≤Rf/Df≤30, and 1.60≤Dv/Df≤3.20, where Jr=N/(π*(D−Df))×(Dh×Sin(π/N)−(Df/Cos(αx π/180))) and α is the helix angle, expressed in degrees, of each metal filamentary element (54).

A braiding apparatus includes a base, a strand supplier supplying a core strand, strand carriers shuttling on the base and providing carrier strands that wrap the core strand and twist together to form a rope, a guiding pulley disposed above the strand carriers to feed the rope to a strand collector, and a control device having a driving source connected to the guiding pulley, at least one recognition unit arranged on the guiding pulley, a sensor disposed relative to the guiding pulley, and a controller electrically connected to the sensor and the driving source. The sensor counts the number of the recognition unit passing the sensor when the guiding pulley rotates to measure lengths of divided sections of the rope. Concurrently, the controller controls the driving source and the guiding pulley to have different rotational speeds, thereby controlling different braid densities of different sections of the same rope precisely.

A wire fabrication apparatus includes a number of fluid channels, each fluid channel configured to receive a first portion of a corresponding wire of a number of wires and including a fluid flowing in a first direction therein. A twisting mechanism is configured for attachment to second portions of the number of wires, the twisting mechanism being configured to draw the number of wires from the number of fluid channels in a second direction opposite to the first direction and to twist the number of drawn wires. A controller controls twisting mechanism to form a twisted wire, including controlling the twisting mechanism to draw the number of wires from the number of fluid channels in the second direction and to twist the drawn wire.

A cord (50) comprises a single layer (52) made up of N helically wound metal filamentary elements (54) having an outer diameter D, the metal filamentary elements (54) defining an internal enclosure (58) of the cord of diameter Dv. Each metal filamentary element (54) has a diameter Df and a helix radius of curvature Rf. With this cord (50), D, Dv, Df and Rf being expressed in millimeters: 0.10?Jr?0.25, 9?Rf/Df?30, and 1.60?Dv/Df?3.20, where Jr=N/(?*(D?Df))?(Dh?Sin(?/N)?(Df/Cos(???/180))) and ? is the helix angle, expressed in degrees, of each metal filamentary element (54).

A braiding apparatus includes a base, a strand supplier supplying a core strand, strand carriers shuttling on the base and providing carrier strands that wrap the core strand and twist together to form a rope, a guiding pulley disposed above the strand carriers to feed the rope to a strand collector, and a control device having a driving source connected to the guiding pulley, at least one recognition unit arranged on the guiding pulley, a sensor disposed relative to the guiding pulley, and a controller electrically connected to the sensor and the driving source. The sensor counts the number of the recognition unit passing the sensor when the guiding pulley rotates to measure lengths of divided sections of the rope. Concurrently, the controller controls the driving source and the guiding pulley to have different rotational speeds, thereby controlling different braid densities of different sections of the same rope precisely.