Plastic tie system

Abstract

A low-cost, light-weight, high strength, resilent plastic strapping tie is of simple, substantially rectangular extruded form, used in combination with slip-on adjustable tie attachment means. One laterally applied/removed slip-on attachment has a spring ring coil, for applying anywhere along the length of a tie, or to couple ties together, including embodiments having a hook portion to secure the tie to a tie-down point. The subject strapping tie may be knotted, and may be relatively readily unknotted. Ties of polyolefin and polyurethane can have ultimate tensile strength of up to 8,000 pounds per square inch of strap cross section; with a dog-bone, substantially rectangular cross-sectional profile with enlarged rounded edges. The range of small, lightweight attachment fittings includes a mini shock cord equipped with a hook.

1 . A light-weight, high strength, thermo-plastic elastomer strapping tie of extruded form, selected from the group consisting of polyolefin and polyurethane plastic, wherein said extruded form is molecularly semi-oriented, possessing high elastic recovery and an ultimate tensile strength in the range of 6,000 to 8,000 pounds per square inch, in use to enable utilization thereof as a high strength elastic tie.  
     
     
         2 . The strappimg as set forth in  claim 1 , said polyurethane plastic being selected from the group consisting of polyester and polyether thermosetting elastomers having an original tensile strength in the range of about 600 to about 8,000 p.s.i.  
     
     
         3 . The strappimg as set forth in  claim 1 , said extruded form being substantially rectangular and having a width to thickness ratio in the range from 6 to 1 to 25 to 1.  
     
     
         4 . The strappimg as set forth in  claim 1 , said extruded form being substantially cylindrical.  
     
     
         5 . The strappimg as set forth in  claim 1 , said extruded form having a dog-bone section profile with enlarged edge portions.  
     
     
         6 . The strappimg tie as set forth in  claim 1 , in combination with tie attachment means, enabling ready attachment of the strapping to an attachment point.  
     
     
         7 . The combination as set forth in  claim 6 , wherein said strapping tie comprises a first length of said strapping, and said tie attachment means comprises a separable spring ring device.  
     
     
         8 . The combination as set forth in  claim 6 , wherein said strapping tie comprises a first length of said strapping, and said tie attachment means comprises an S-hook portion, providing in use for lateral sliding insertion of said strapping tie in engaging relation with said S-hook portion.  
     
     
         9 . A unitary hook fastening device having an S-shaped portion to receive a strapping tie in secured, inserted relation therewith, and a hook portion extending therefrom, for securing the device to a strong-point.  
     
     
         10 . The unitary hook fastening device as set forth in  claim 10 , including a hook portion projecting substantially at rightangles from said S-hook portion, in use to facilitate access thereto.  
     
     
         11 . The unitary hook fastening device as set forth in  claim 9 , including a keeper tube slidably mounted upon said hook portion, being movable into engaging relation with said S-shaped portion, whereby said strapping tie is retained in engaged relation with said S-shaped portion.  
     
     
         12 . The combination as set forth in  claim 7 , said spring ring device having a resilient, re-entrant hook distal end portion engageable with an arcuate ring portion of said device, by entry within said arcuate ring portion.  
     
     
         13 . A method of making a semi-oriented plastic strap tie, selected from the group consisting of polyolefin and polyurethane plastics, including the steps of extruding the plastic through a die of predetermined size and profile; cooling the extruded plastic; passing the cooled plastic through a first take-off roll nip running at a first speed; and passing the cooled plastic through a second puller roll nip running at a second, higher speed, wherein said second speed is two to three times faster than said first speed, to stretch, reduce and semi-orient the molecular structure of said strap tie.  
     
     
         14 . The method as set forth in  claim 13 , said polyurethane plastic being selected from the group consisting of polyester and polyether thermosetting elastomers.