Flexible Thread Technology (FFS) was invented by Robert Fullerton in 1979 and has 6 U.S. patents granted and 4 new, “Automatically Mechanically Locking Fastener/Coupler” provisional patents proposed in his name at this time. The concept utilizes an outer body containing three threaded fasteners.

The success of these projects prompted NASA to include FFS Technology as a “Recommended Technique for Effective Maintainability in Selection of Robotically Compatible Fasteners and Handling Mechanisms”.

NASA officially acknowledged the history and widespread use of the FFS in its 1989 Spin-off publication and included it in NASA’s official Policy for Safety and Mission Success (NPD8700) as a ‘Recommended Technique for Effective Maintainability’ in the section on Selection of Robotically Compatible Fasteners and Handling Mechanisms (NTM4628).

The concept was first used by NASA in 1989 on Shuttle flight STS29, and later, four specifically designed Zip Nuts were used to connect the Hand Hold to the Wide Field/Planetary Camera during the Hubble repair. Since then, the concept has been used in space about 20 times, including 9 times for E.V.A.

What is novel about this design?

The ability to control the transfer of volatile cryogenic small molecule fluids or gases with an automatic mechanical locking feature to eliminate the possibility of accidental loosening or other disengagement of couplers, producing a catastrophic as well as life-endangering possibility. Eliminating the helical leak path present in the standard threaded coupling.

Couplings can be achieved with this concept by a human or a remotely controlled robot.

Benefit 1:

The Ziplock Cryogenic Coupler prevents misalignment and disengagement caused by thermal shifts and high-frequency vibrations during high-pressure transfer of small-molecule fluids or gases, which could lead to catastrophic and life-threatening situations.

Benefit 2:

The Ziplock Cryogenic Coupler provides a fast, safe connection for potentially hazardous high-pressure small-molecule fluids and gases in a controlled, long-term environment.

Manufacturing:

This concept will be easily manufactured and assembled by modern Automated CNC Machinery.

How it came to be:

Fullerton Design was approached by L3AMI, which was having problems with the Alcoa Mark IV Structural Panel Fastener.

During the development of a “proof of concept,” the potential for a locking hydraulic coupler became clear.

Current status:

A proof-of-concept coupler has been built for fit checks and manufacturing repeatability, and all initial concept engineering requirements have been met, including achieving 3,500 psi secure, advancing the concept to the next stages to perfect the automatic mechanical locking feature.

Market potential:

In assessing market potential, it was determined that this concept, with minor modifications, will serve several diverse markets, including but not limited to Fire Hose, food transfer, fuel, and garden hose. The initial time would be better spent finalizing the Cryogenic version, which is much more critical, as lives may be at stake.