1. Field of the Invention
This invention relates to the field of cords or cables. More specifically, the present invention comprises a cord construction, a cord termination, and an adjustable clasp which can be used to attach a cord to another device.
2. Description of the Related Art
Various fastening mechanisms are known for attaching cords or cables to devices (Throughout this disclosure, the terms “cord” and “cable” are considered synonymous). Fastening mechanisms are particularly important when the cord supports a tensile load. Most fastening mechanisms are not adjustable and do not allow the user to easily vary the length of the cord. These fastening mechanisms are typically semi-permanent. Often the user can shorten the length of the cord by cutting the cord next to the fastener and reattaching the same fastener or a different fastener to the shortened cord. It is generally inadvisable if not impossible to lengthen the cord because conventional fastening mechanisms damage the portion of the cord at the location where the fastener is attached.
One example of applications where it is useful to have an adjustable fastening means is control cable applications. For purposes of illustration, a bicycle control cable, such as a control cable used for braking or shifting, will be considered. A complete control cable consists of the tensile carrying cable itself, a first terminating device on one end, and a second terminating device on the other end. Because the length of such cables often need to be adjusted, at least one of the two terminating devices will normally include an adjustment feature.
Bicycle control cables are typically composed of an inner steel cable which is wrapped in a protective and supportive outer sheath. Various fastening and actuating devices are customarily attached to the opposite ends of the inner steel cable. These can include combinations of crimps, ferrules, donuts, caps and other hardware. Such fastening devices are used to connect the inner steel cable to a braking handle (or shifting lever) on one end and to the braking mechanism (or shifting mechanism) on the other end. Generally, some piece of hardware is crimped on to both ends of the inner steel cable so that the cable can be fastened to these other devices.
Crimping is a semi-permanent method of attaching hardware to the inner steel cord. To remove the hardware, the steel inner cord must generally be cut beneath the crimp. If the user attaches the hardware too short to reach the device it is designed to actuate or if the user moves the actuating mechanism further from the device that is actuated, the user will often have to replace the control cable. Accordingly it would be desirable to have an adjustable fastening mechanism that can be attached without damaging the cord.
In recent years the traditional steel cable has been replaced by advanced synthetic fibers. These fibers, when compared to steel, are much smaller and slicker. Crimping does not work well for synthetics, since the crimping force required to grip such a slick surface will often damage the fibers. Synthetic fibers also have very little compressive stiffness. This fact means that a bundle of such fibers will tend to be loosely organized. It will not maintain a circular cross section when passed around a bend but will flatten instead—producing uneven load distribution across the cable's cross section. An integrated cable, termination, and clasp system should ideally take into consideration the new design constraints imposed by the growing use of synthetic fibers.