Introducing Safe-T-Cable™

BACKGROUND

Self locking fasteners are being used extensively in the Aircraft/Aerospace industry.  However, there will always be a need to install constraining (safety) devices to many bolts and other threaded fasteners in applications where self lockers cannot be used.  Their purpose is to restrict (to a minimum) the unintentional rotation of the fastener.  The traditional method (devised in the early 1900's) is through the use of Hand Twisted Lockwire (often called Safety wire.)

The only changes which have occurred since the early uses of Lockwire are the tremendous costs in the installation of this material, and the levels of sophistication in the systems on which Lockwire is being installed.  It is used in Jet Engine systems, Airframes, Electronics, Space Vehicles, and Land/Sea based Systems.

The process of installing remains awkward and costly, and the inspection process is demanding.  The removal and rework of installed Lockwire is a common occurrence.

Safe-T-Cable™ was invented to address these problems in modern Airframe and Engine Systems.  The Safe-T-Cable™ Kits are consistent in their construction/application, and the user-friendly tooling guarantees a secure and reliable installation each time it is used.  Operator training is simple, Inspection is objective, and rework is virtually eliminated.  This results in fewer demands on the Operator, Inspector, and Maintenance personnel.

CONSTRUCTION

Safe-T-Cable™ is constructed of high tensile strength, stranded cable.  It is more flexible than its Lockwire counterpart, although the working diameters are equivalent.  this provides a stronger assembly which has greater strength and lighter weight.  The cable ends are electrically fused to form an easy threading end ball.

The cable is pre-cut to various lengths, ad is supplied with a square-formed end cap attached to one end.  Safe-T-Cable™ is available in three nominal diameters.  the .040 inch diameter cable is constructed of 7x7 stranded ropelay material. Ropelay construction is also used for the 3x7, .032 diameter cable while the .020 diameter cable is made of 1x7 unilay material.

The ferrules are precisely manufacturing to a size and hardness which assures their compatibility with the cable and application tooling.  They are supplied (50 pieces each) in an easy loading disposable cartridge, which provides orderly containment of individual ferrules, and the easy release of individual ferrules as they are required.  this feature minimizes the possibility of Foreign Object Damage (FOD).

TESTING

The application of Safe-T-Cable™ is consistent from one installation to the next due to the repeatability and dependability of the application and the quality of the materials used in the manufacture of Safe-T-Cable™ Kits.  All that is required to assure overall reliability in manufacturing and maintenance use is a periodic test of a few crimped cable assemblies.  DMC offers full instruction and the test equipment to perform these simple tests in either remote or test lab locations.

SAFE-T-CABLE™

The pre-assembles cables have a square formed end cap securely attached to one end.  This provides a positive stop when threaded through a fastener.  The other end is electrically fused such that it will easily thread through the series of fasteners that are to be secures.  The flexible cable material is lightweight and easy to handle.  The stainless steel materials will not corrode or deteriorate while in use.  (See chart on the following pages for material, size, and part number.)  All Safe-T-Cable™ kits and assemblies are supplied 50 pieces per package.

FERRULES AND CARTRIDGE LOADING SYSTEM

The individual crimp ferrules are preloaded into disposable cartridge unit (50 pieces per cartridge) which allows convenient transportation, storage, and availability of these components.  The ferrules are easily extracted individually by threading the cable end through the ferrule, and snapping the ferrule loose.  This system, when properly used, eliminated the possibility of Foreign Object Damage (FOD).