US 3568128 A
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Description (OCR text may contain errors)
llnited States Patent 107, 119, 125, 149, 177, 208, 263, 265; 333/8,96; 174/71, 71 c 78;24/81 (BA) References Cited UNITED STATES PATENTS 549,466 11/1895 Seaman 297/205 4/1965 Klassen 339/208X Assistant Examiner- Patrick A. Clifford Attorney-Allen and Chromy ABSTRACT: A ground clamp for making a ground connection to the sheath of a coaxial cable. The ground clamp is provided with relatively wide metal clamping members having arcuate portions for clamping the metal sheath therebetween after the outer insulation is stripped from the cable and the sheath is exposed. These portions of the ground clamp cable are enclosed in a plastic housing which is made of two identical sections that are adapted to be held together by the anchoring screw. The housing sections are provided with inwardly extending ridges that engage the outer plastic coating of the cable to form seals therewith and prevent moisture from entering the housing.
PAT ENTEDMAR zlsn SHEET 1 [IF 2 INVENTOR. GEORGE W.TAYLOR ATTORNEYS PATENTEDHAR 2|91| "3568.128
SHEET 2 OF 2 INVENTOR.
w. TAYLOR $4" MIX/o ATTORNEYS GEORGE GROUND CLAMP DESCRIPTION OF THE INVENTION large contact area with the sheath of the coaxial cable.
Still another object of this invention is to provide an improved ground clamp for coaxial cables in which the grounding connection to the cable is housed in a two-piece plastic housing that is adapted to be assembled in weathertight fashion;
Another object of thisinvention is to provide an improved device for removing a predetermined amount of insulation covering from the coaxial cable to expose the metal sheath of the cable for contact with the ground clamp connection.
Other and further objects of this invention will be apparent to those skilled in the art to which it relates from the following specification, claims and drawings.
In accordance with this invention, there is provided a ground clamp for coaxial cables in which the ground connection to the metal sheath of the coaxial cable is made of two-flat metal strips that are adapted to be clamped together and which are adapted to make a rather large and broad contact with the metal sheath of the cable. This contact with the sheath of the cable is housed in a plastic housing that is made in two identical sections which are adapted to be assembled in opposing relation and enclose the grounding connection therein in a cavity provided for this purpose. The housing sections are each provided with inturned ridges that engage the outside plastic coating of the cable and provide a weathertight seal therewith, when these sections are assembled and when they are held upon a suitable support by the supporting screw provided thereto.
In accordance with this invention there is also provided a tool that is used for removing a predetermined length of the outside plastic coating or covering from the coaxial cable so that a suitable length of the metal sheath of the coaxial cable is exposed. The grounding clamp provided in this invention is adapted to be applied to this exposed part of the sheath. This tool when properly used is adapted to remove the correct length of the outer plastic coating of the coaxial cable for receiving the grounding connection. Thus, by using this tool the operator will not remove more of the plastic coating than is necessary. This is important since removal of too great a length of this coating would impair the proper sealing of the housing with the outer coating of the coaxial cable.
Other and further features of this invention will be apparent to those skilled in the art to which it relates from the following specification, claims and drawings in which, briefly:
FIG. 1 is a perspective view showing this ground clamp installed on a short length of coaxial cable;
FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1;
FIG. 3 is a side view of the ground clamp shown in FIG. 1;
FIG. 4 is a top view of the ground clamp;
FIG. 5 is a plan view of the ground clamp with the top section of the housing removed;
FIG. 6 is an end view of the tool used for removing a predetermined length of the plastic covering from the cable;
FIG. 7 is a side view of the tool shown in FIG. 6; and
FIG. 8 is a fragmentary view showing the tool illustrated in FIG. 7 in position to slit the predetermined length of cable covering that is to be removed from the cable.
Referring to the,drawing in detail, reference numeral 10 designates the housing of this ground clamp which may be made of suitable plastic or other electrically insulating material. The housing is made of two identical sections 11 and 12 which are adapted to be assembled in opposing relation and which are held clamped together by the supporting screw 13. The supporting screw 13 is of the conventional wood or other type and it holds the housing clamped against the supporting member 14 which may be a wooden member under a building or on the side thereof or which may be a separate member such as a post provided for this purpose.
The coaxial cable 15 is of conventional construction and it is provided with an internal conductor 16 that is positioned substantially in the center of the insulation 17. The sheath 18 of the coaxial cable 15 is positioned on the outside of the insulation 17 and it is also of electrically conducting material. The sheath 18 may be made of a large number of small wires braided together to lend flexibility to the cable. An outer coating or protective covering 19 of insulating material such as plastic is provided on the outside of the sheath 18.
A predetermined length of the outer covering 19 is removed from the cable so that the contact members 20 and 21 made of metal may be applied to the uncovered sheath 18. The contact members 20 and 21 are provided with substantially semicircu' lar sections which are adapted to be clamped in opposing relation around the exposed part of the sheath 18 and held in this relation by the bolt 22. Also when the housing sections 11 and 12are assembled the portions thereof which arev opposite the members 20 and 21 are adapted to engage these members and press them together when the screw 13 which supports the housing on a member 14, is tightened. These edges 11a and 12a may be somewhat thinned and feathered so that tightening of the screw 13 tens to make these edges bulge outwardly slightly and provide a more effective weather seal with the members 20 and 21, respectively.
The housing sections 11 and 12 are provided with a cavity for receiving a length of the coaxial cable. The ends of this cavity have semicircular inturned internal ridges llbll'c, and 12b12c, respectively, which are of substantially semicircular configuration and which press into the outer plastic coating 19 of the coaxial cable as shown in FIG. 2 to provide a weathertight seal between these housing sections and the plastic coating 19 when the housing sections 11 and 12 are assembled on the cable and the screw 13 is tightened to hold the sections firmly together. The bolt 22 also functions to anchor the ground wire connection 23 to the strips 20 and 21. The ground wire 23 is connected to a suitable metal rod or post (not shown) which is inserted into the soil to provide a grounding connection to the strips 20 and 21 and to the sheath 18 of the coaxial cable.
Both of the housing sections 11 and 12 are the same and they may be made in the same cavity of a mold out of suitable plastic material. Each of these sections is provided with a small pin or plug 24 as shown in FIG. 5 which is molded integral with the housing section and is located in a corner area of the housing section. An opposite corner area of the housing section is provided with a hole or recess 25. Thus, when a top section 11 of the housing is assembled with the bottom section 12 of the housing the pin 24 of the top section will be positioned in the hole 25 of the bottom section and the pin 24 of the bottom section will be received in a hold 25 in the top section. These pins and holes are made in relatively close tolerances so that they insure substantially perfect alignment of the top and bottom sections 11 and 12 when these are assembled.
The tool illustrated in FIGS. 6, 7 and 8 is provided for removing a suitable length of the outer covering 159 of the coaxial cable to expose the sheath 18 for receiving the contact strips 20 and 21. This tool comprises two cutter devices 26 and 27 which are held together by suitable spacers 28 and 29 and bolts 30 and 31. A spacer 34a which is similar to spacers 28 and 29, is provided around the pivoting bolt 34 of the cutter devices. Spacers 28 and 29 are in the form of suitable tubular members and the cutting tools 26 and 2.7 areheld in firm engagement against the ends ofthese spacers by screws or bolts 30 and 31, respectively, which are positioned in suitable holes provided in the handles of these tools. Each of the cutting tools 26 and 27 is of conventional construction and each is provided with a pair of handle members 32 and 33 shown in FIG. 7, which are pivotally held together by the bolt 34 and spacer 34a. Sharp recesses 35 and 36 of substantially arcuate configuration are provided to the jaws of members 32 and 33, respectively. When the coaxial cable is placed between the open jaws of the two tools and these sharp recesses are brought together upon the cable the outer covering 19 is cut thereby to provide the cuts 19a and 19b as shown in FIG. 8. After the cuts 19a and 1% which are separated along the length of the cable by a distance somewhat larger than the width of the connecting strips and 21 the cable is slightly bent as shown in FIG. 8 so that the cuts 19a and 19b are opened or widened to permit insertion therein of the points 37 and 38, respectively, of one side of the cutting tool. The jaws of the cutting tool are then closed by pressing on the handles thereof and the portion of the covering 19 between the cuts 19a, 19b is severed longitudinally. This portion of the covering 19 may then be removed by gripping one of the corners thereof and pulling it off of the cable thereby exposing a part of the sheath 18.
While 1 have shown a preferred embodiment of the invention, it will be apparent that the invention is capable of variation and modification so that is its scope should be limited only by the scope of the claims appended hereto.
l claim: a
1. In a ground clamp for making a ground connection to the metal sheath of a coaxial cable which is provided with an outer insulation covering, the combination comprising a two piece housing of electrically insulating material, said two pieces being adapted to be interchangeably assembled so that one piece forms a top and the other forms a bottom of said housing, said housing having a cavity extending across the length thereof, said cavity having a generally circular cross section and the opposite end portions of said cavity snugly engaging the insulation covering of said coaxial cable, said two piece housing having a narrow opening on one side thereof leading into the side of said cavity, a ground connection for said sheath comprising at least one metal strip member having an arcuate end portion engaging a portion of said sheath that has been exposed, said strip member extending out of said cavity in said housing through said narrow side opening, said housing having a hole formed therethrough from the top to the bottom thereof, a fastening member positioned in said hole for bolding said two piece housing assembled so that the outer covering of said insulation is clamped in said cavity and means provided to the portion of said strip member extending out of said narrow opening formaking electrical connection thereto.