Patents Represented by Law Firm Nutter, McClellen & Fish
  • Patent number: 4975543
    Abstract: An energy-absorbing towline (14) comprises an elastomeric core (16) having a set of internal polymeric strands (18) helically wound around the outer surface (20) of the core in a first direction and a set of external polymeric strands (22) helically wound around the outer surface (24) of the internal strands in a direction opposite to the first direction. There may be more internal strands than external strands in order to maintain torque balance as the cable elongates. Each of the internal and external strands consists of a plurality of filaments (30), and each external strand (22) may have fewer strand filaments than each internal strand (18) so as to aid in torque balancing. Electrical conductors (26) may be helically disposed between turns of the external or the internal strands. When the towline experiences tension, the elastomeric core elongates, as do the helixes. But the diameters of the helixes contract, so the strands themselves do not elongate.
    Type: Grant
    Filed: June 30, 1989
    Date of Patent: December 4, 1990
    Assignee: Sanders Associates, Inc.
    Inventor: Roger I. Saunders