Variable-rate spring marine docking cable

Abstract

The variable-rate spring marine docking cable is a device for allaying the shock forces on moored floating structures due to wind, wakes, tides and storms. The device includes a variable-rate spring member similar to an automobile strut. Respective cables are attached at first ends to each respective end of the spring member. One of the cables is attached at its second end to a floating structure such as a dock or boat. The other cable is attached at its second end to a mooring pile, pier, or other fixed object.

1 . A variable-rate spring marine docking cable, comprising:
 a variable-rate compression spring member having a proximate end, a distal end, an axial length, and helical coils;   a two-part cable having a first part extending from the proximate end of the spring and a second part extending from the distal end of the spring;   means for compressing the coil when a tensile force is applied to at least one part of the two-part cable, the means for compressing extending through the helical coils.   
     
     
         2 . The variable-rate spring marine docking cable according to  claim 1 , wherein said compression spring member is a helical spring member. 
     
     
         3 . The variable-rate spring marine docking cable according to  claim 1 , wherein said means for compressing comprises;
 a first plate and a second plate, each of the plates having an inner surface, an outer surface, and a pair of openings defined therein, the first plate being attached to the proximate end of the spring member and the second plate being attached to the distal end of the spring member;   a first tube having a first end and a second end, the first end of the first tube being attached to the first plate and defining one of the openings in the first plate, the second end of the first tube extending through one of the openings in the second plate, the first part of the cable extending through the first tube;   a second tube having a first end and a second end, the first end of the second tube being attached to the second plate and defining one of the openings in the second plate, the second end of the second tube extending through one of the openings in the first plate, the first and second tubes being parallel to each other and extending coaxially through the helical coils, the second part of the cable extending through the second tube; and   a first stop member attached to the first part of the cable at the distal end of the spring and a second stop member attached to the second part of the cable at the proximate end of the spring, the stop members bearing against the corresponding plate to compress the end of the spring when the tensile force is applied to the corresponding part of the cable.   
     
     
         4 . The variable-rate spring marine docking cable according to  claim 3 , wherein said the first and second parts of said two-part cable comprise docking cables. 
     
     
         5 . A variable-rate spring marine docking cable according to  claim 1 , wherein said means for compressing comprises a pair of round, metallic bars disposed extending through the helical coils, each of the metallic bars being U-shaped and having a base end and free ends, the free ends being formed into hooks engaging the corresponding end of said spring. 
     
     
         6 . The variable-rate spring marine docking cable according to  claim 5 , wherein the first and second parts of said two-part cable are attached to the base end of a corresponding one of the U-shaped bars. 
     
     
         7 . A variable-rate spring marine docking cable, comprising:
 a variable rate, helical compression spring member having a proximate end, a distal end, an axial length, and helical coils defining an inner volume;   a first plate and a second plate, each of the plates having an inner surface, an outer surface, and a pair of openings defined therein, the first plate being attached to the proximate end of the spring member and the second plate being attached to the distal end of the spring member;   a first tube having a first end and a second end, the first end of the first tube being attached to the first plate and defining one of the openings in the first plate, the second end of the first tube extending through one of the openings in the second plate;   a second tube having a first end and a second end, the first end of the second tube being attached to the second plate and defining one of the openings in the second plate, the second end of the second tube extending through one of the openings in the first plate, the first and second tubes being parallel to each other and extending coaxially through said volume;   a first docking cable extending through the first tube; and   a second docking cable extending through the second tube.   
     
     
         8 . The variable-rate spring marine docking cable according to  claim 7 , further including a pair of stop members disposed on said docking cables on opposite ends of said spring. 
     
     
         9 . The variable-rate spring marine docking cable according to  claim 8 , wherein the first end of said first tube is attached to the inner surface of the first plate and wherein the first end of said second tube is attached to the inner surface of said second plate. 
     
     
         10 . A variable-rate spring marine docking cable, comprising:
 a variable rate, helical compression spring member, the spring member having a proximate end, a distal end, an axial length and helical coils defining an inner volume;   first and second round, metallic bars disposed in the inner volume, each of the metallic bars being U-shaped and having a base end and free ends, the free ends forming hooks engaging the corresponding end of the spring member; and   cables extending from the base ends of the bars.   
     
     
         11 . The variable-rate spring marine docking cable according to  claim 10 , wherein the base of said first metallic bar extends slightly beyond the proximate end of said spring member and the free ends of said first metallic bar are hooked onto the distal end of said spring member. 
     
     
         12 . The variable-rate spring marine docking cable according to  claim 10 , wherein the base of said second metallic bar extends slightly beyond the distal end of said spring member and the free ends of said first metallic bar are hooked onto the proximate end of said spring member. 
     
     
         13 . The variable-rate spring marine docking cable according to  claim 10 , wherein the base of said first metallic bar extends slightly beyond the proximate end of said spring member and the free ends of said first metallic bar are hooked onto the distal end of said spring member and wherein the base of said second metallic bar extends slightly beyond the distal end of said spring member and the free ends of said first metallic bar are hooked onto the proximate end of said spring member.