Electricity: conductors and insulators – Overhead – Ground clamps and cable clips
Reexamination Certificate
1999-03-26
2001-11-13
Reichard, Dean A. (Department: 2831)
Electricity: conductors and insulators
Overhead
Ground clamps and cable clips
C242S556000
Reexamination Certificate
active
06316723
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to cable braid splicing devices, and more specifically to a method for splicing together two metal braids used to shield electrical cables from electromagnetic interference (EMI). This invention further relates to a splice that can be installed or repaired by hand, without the use of a special tool, and which will accommodate a wide range of cable sizes.
2. Description of the Prior Art
Electrical cables used for carrying power or electrical signals typically require the use of a metal braid to shield the wires from electromagnetic interference. It is frequently necessary to mechanically and electrically join two shorter pieces of braid on a single cable. In such instances it is desirable to have a braid splice that can be installed and repaired by hand, without the need for tooling. Further, it is desirable to have one component that can accommodate a wide range of cable diameters. Moreover, it is desirable to have a splice that can support axial loading of the cable, allow for cable bending, be resistant to wear from vibration and which will have a low electrical resistance. Finally, it is desirable to have a cable splice that can be installed without having to slide a circular device over the end of the cable.
Splicing methods currently in use fail to meet the foregoing objectives. For example, solderable cable splice systems have good electrical properties but are difficult to install and generally not repairable. Several current splicing methods use a ridged ferrule underlying both braids, along with a type of band to strap around the ferrule. These methods require special tools and require that the ferrule be sized closely to that of the wire cable.
Another method of braid splicing employs a special ferrule and a coiled ribbon spring to hold the braid against the ferrule. The ribbon spring can be installed and removed by hand without tooling, but it requires a specially sized ferrule that must be slid over the cable prior to splicing the ends. The ferrule greatly limits the size range of the splice, and also limits cable flexibility at the splice. In addition the need to slide the ferrule over the cable can make repair difficult for a long cable and may necessitate the removal of end fitting hardware.
Braid splicing methods that employ an inside ferrule have several limitations. Firstly, they cause a sizable raised ridge in the cable that can limit the passage of the cable through holes. Secondly, they are unsuited to cable with tightly woven braids as the braid is incapable of expanding over a ferrule; in that event, other termination methods must be used.
Methods of braid splicing that clamp overlapping braids directly onto the cable can fail by one of two means. If the clamping force is great, the braid will damage the wires under the splice. If the clamping force is too small, the splice will fail under an axial load.
Summarily stated, there are no currently existing cable braid splicing methods that are easily installed by hand and that can be readily repaired or replaced.
OBJECTS AND ADVANTAGES
In accordance with the embodiments of the present invention, it is an object of the present invention to provide a cable braid splice that can be installed without the use of tools.
It is a further object of the present invention to provide a cable braid splice that will easily accommodate a wide range of cable sizes.
It is a further object of the present invention to provide a cable braid splice that is installed, replaced, or repaired without having to slide components over the end of the cable to be repaired.
It is yet another object of the present invention to provide a cable braid splice that can be installed without the use of heat.
It is a further object of the present invention to provide a cable braid splice that has bonding strength equivalent to that of the uncut braid.
It is yet another object of the present invention to provide a cable braid splice that does not greatly limit the flexibility of the cable in the region of the splice.
It is still another object of the present invention to provide a cable braid splice with a very low profile that will not greatly affect the diameter of the cable.
It is again an object of the present invention to provide a cable braid splice that is resistant to vibration.
It is yet again an object of the present invention to provide a cable braid splice that has a low electrical resistance.
It is a further object of the present invention to provide a cable braid splice that will not damage cable wires in the area of the splice.
It is yet another object of the present invention to provide a cable braid splice that will provide reliable ground leads from individually shielded wires.
It is still another object of the present invention to provide a cable braid splice that is reparable and electrically secures individual braids to a bulk braid.
It is another object of the present invention to provide a cable braid splice that can be used to terminate a cable braid to an adapter braid sock.
SUMMARY OF THE INVENTION
The cable braid splice and cable braid splicing method of the present invention accomplish each of the foregoing objects. What is disclosed is a cable braid splice, and method for using the same, for creating a mechanical and electrical junction between two pieces of metal braid covering a single cable is disclosed. In the first and simplest embodiment, the first component of the splice comprises a coiled ribbon spring having a first and second ends, configured with coils at each end, wound in opposing directions so that the coils are in contraposition, and a joining segment of ribbon interposed between the coils.
The second component of the splice comprises a thin pliable “C” clip for placement partially around a cable bundle and underneath overlapping cable braids. The clip is made of a springy material that tends to compress inward and to hold itself against the wire bundle. Alternatively, it can be made of a non-springy material that can be easily shaped into a C-shape.
In a second preferred embodiment, the coiled ribbon spring includes an offset at the middle of the joining segment so that the opposing coils wind parallel to one another into a partial side-by-side relationship. In a third preferred embodiment, the coiled ribbon spring includes an arched bridge joining the two coiled ends, such that the coiled ends wind parallel to one another into a complete side-by-side relationship.
The mechanical clamping strength of the coiled ribbon spring can vary according to the thickness of the material, the width of the band, and the tightness of the rolls. Two or three spring sizes can accommodate a full range of cables from below ¼ inch, to over 2 inches.
A method of using the splice is also disclosed, generally comprising the steps of placing a “C” clip over a wire bundle and underneath two opposing layers of braid. The “C” clip is sized to encompass approximately half the circumference of the cable bundle, leaving a gap on the other half. The braids are pulled together and overlapped so that each cover the “C” clip. They are then pressed down to form a ridge at the location of the clip. The coiled ribbon spring is then applied by wrapping the opposing coils several times around the cable and opposing braids on each side of the ridge. The coiled spring is positioned such that the joining segment of the coil crosses the ridge at the position of the gap in the “C” clip.
REFERENCES:
patent: 5028742 (1991-07-01), Redman
Goett Edward P.
Woehl Roger
Engineered Transitions Company, Inc.
Johnson Larry D.
Johnson & Stainbrook
Reichard Dean A.
Stainbrook Craig M.
LandOfFree
Repairable braid splice does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Repairable braid splice, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Repairable braid splice will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2568826