Coaxial cables used by the CATV industry utilize aluminum for the outer conductor and aluminum or copper for the inner conductor.
Both aluminum and copper are "soft" materials and exhibit cold-flow characteristics under compression.
Electrical connectors used on coaxial cables employ compression connections on both the inner and outer conduotors. The very best electrical connectors that exhibit fine electrical characteristics when initially installed will deteriorate as soon as cold-flow occurs. Cold-flow will occur. There is no way to prevent it. How long it takes for this action to be significant depends upon the initial pressures employed in the connector design and the ambient temperatures encountered.
By the very nature of the compression connection, even a very minute increment of cold-flow results in a gap in the circuit. The obvious answer is to back the compression connection up with a spring.
How to do that and still release the cable when desired constituted the problem.
The solution was obtained with a unique clamp design and by taking advantage of the "spring" characteristics of the newer plastic materials.
In the new design every increment, however minute, is immediately compensated for by a spring back-up force. In this manner initial electrical characteristics can be expected to be maintained for many years of severe service.