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ABSTRACT:
Berkeley Lab researchers have invented a way of bundling or strapping objects together tightly that combines the usefulness of a tie wrap and heat shrink tubing. The new invention includes a buckle so that it can be applied in an initially open loop to structures but all or part of its construction consists of the heat sensitive material so that once installed heat instead of a buckle tightening procedure can be used for tightening. There is no need to provide access for a tool or hands as the heat can be applied from a distance.
There are currently two common methods for strapping and bundling objects tightly together. One uses an (initially) open ended clamp (or tie wrap) and the other uses a closed ended shrinkable tubing (or shrink tubing).
Tie wraps start as a strip with two ends that is wrapped around an object to be held and then the ends are joined to form a loop around said object. Usually a ratchet type buckle that can be pulled together to provide the correct length is used to fasten these two ends. The object that is tied can be very long or even in the form of a closed loop and still accept the application of the tie wrap. To tighten the buckle a tool or space to fit a worker's hands for a good tug is needed up close to the application.
Heat shrinkable tubing is made from a thermally sensitive material that shrinks in dimension when heated. The tubing can be slipped over an object while in the oversize state and then heated with hot air (for example) to cause the tubing to reduce in diameter and close on the object. The object must have a geometry that allows the application of the closed section tube, which is to be fitted end-on. After fitting heat can be applied diffusely from some distance and still enable the shrinkage to occur.
The Berkeley Lab invention enables multiple assemblies to be fitted and then tightened as a group with one application of heat. It also allows fitting shrinkable tubing to endless or looped structures without disassembly of structures by having a seam in the tubing which is closed on installation. In addition, it is quicker and ensures more secure installation than stretching tape |
