US Patent 10529465 Waterproof signal cable structure

A signal cable structure includes a set of strands, an outer insulation tube and a water swellable powder. The set of strands includes a plurality of twisted pairs. The twisted pairs are enclosed to form a center portion, and each of the twisted pairs includes two wires intertwined with each other. The outer insulation tube sheaths the set of strands; an outer ring portion is surrounded outside the set of strands and formed between the outer insulation tube and the set of strands. The water swellable powder is distributed in the outer ring portion, and the center portion of the set of strands is not distributed with the water swellable powder. Thereby, a signal cable with waterproof performance is provided.