US3564119A

US3564119A - Pressure-equalizing accessory for cables

Info

Publication number: US3564119A
Application number: US879137A
Authority: US
Inventors: John T Thompson; George W Gillemot
Original assignee: Individual
Current assignee: Individual
Priority date: 1969-11-24
Filing date: 1969-11-24
Publication date: 1971-02-16
Anticipated expiration: 1988-02-16

Abstract

A cable-pressure-equalizing accessory having a cup-shaped member fixed to the outer end of a tubular fitting. The latter is equipped with adjustable split ring means for holding the tubular fitting seated in an opening through a cable sheath in a manner excluding moisture and foreign matter while equalizing the internal cable pressure with the ambient pressure.

Description

United States Patent Inventors John T. Thompson 244 Luring St., Los Angeles, 90024; George W. Gillemot, 2331 20th St., Santa Monica, Calif. 90405 Appl. No. 879,137

Filed Nov. 24, 1969 Patented Feb. 16, 1971 PRESSURE-EQUALIZING ACCESSORY FOR CABLES 6 Claims, 7 Drawing Figs.

[1.8. CI 174/135; 174/12; 174/16 Int. Cl H011) 7/00, H02g 15/00 Field ofSearch 174/1, 8,

ll, l2, 13, 15C, 16,70,71, 135

[56] References Cited UNITED STATES PATENTS 2,011,561 8/l935 Chase 174/12 2,859,270 ll/l958 Patchin 174/16 FORElGN PATENTS 1,060,529 1 H1953 France 174/8 1,106,895 3/1968 Great Britain..,. l74/23 Primary Examiner-Laramie E. Askin Attorney-Sellers andBrace ABSTRACT: A cable-pressure-equalizing accessory having a cup-shaped member fixed to the outer end of a tubular fitting. The latter is equipped with adjustable split ring means for holding the tubular fitting seated in an opening through a cable'sheath in a manner excluding moisture and foreign matter while equalizing the internal cable pressure with the ambient pressure.

r P RL'ESSURE-EQUALIZING ACCESSORY I'DR'CABLES I .This invention relates to-electrical cablesand more particularlyfto an improved pressure-equalizing accessory readily assembled to a cable sheath to avoid vthe possibility. of a pressure differential between the interior and exterior of the cable.

The accessory hasa flanged tubular fitting supporting a f s'hitped shroud member with its open end-facingdownwardly and enclosing fine foraminous material crosswise of its interior effective to bar the entry of foreign matter. The installed accessory places the interior of the cable in direct communication with the atmosphere thereby avoiding-the possibility of a pressure differential between the interior and exterior of the cable'despite .changing atmospheric pressures and temperatures.'

Accordingly the primary object, of the present invention is toprovide an improved cable pressure-equalizingaccessory. f Another object of the inventionis .to provide simple,.inexpensive construction easily installed on cables at intervals and operating to vent the interiorof the cables to the atmosphere while'excluding foreign material and moisture.

These and other more specific" objects will appear upon reading the following specification and claims and upon con sidering in connection therewith the attached drawing to which they relate.

Referring now to the drawing in which a-preferred embodimerit of the invention is illustrated: FIG. 1 is an exploded perspective view of one preferred embodiment; FIG. 2 is a cross-sectional view of the FIGJ-embodiment shown installed on a cable;

FIG. 3 is a fragmentary cross-sectionalview taken along line Referring initially and more particularlyto FIGS. 1 and 2 there is shown a typical embodiment of the invention pressure equalizer, designated generally 10. Thisaccessory comprises a tubular fitting 11 having a threaded outer end 12 encircled closely adjacent its rounded forward end 14'witha radial flange 13. A thick gasket ring 15 of'neoprene or the like has a snug fit over end 14 and seats against the forward face of flange 13. The rear face of flange 13 supports the inner surface of a plaque of thin sheetmetal 17 having a length adequate to form a split ring encircling a'cable to whichaccessory l0'is to be attached with a substantial overlap of its op posite ends. Strip 17, preferably formed of stainless steel or aluminum alloy, isprovided with an'opening offset from one end and provided with an upstanding flange 19 the intemaldiameter of which is slightly less than that of fitting 11 at the base of threads 12. It will be understood that strip 17 is forced downwardly over fitting 1-1 causingthe out-turned flange 19 thereof to be expanded slightly as it is forcibly pressed over thejenlarged base end of threads 12. The exterior of the fitting at this enlarged portion may be axially scored so that flange 19 mechanically interlocks therewith during assembly.

Applied to the inner side of the split ring member 17 is a plaque 20 of thick tacky material such as buna well known for its durability, sealing and adhesive characteristics. Prior to installation, its outer surfaceis preferably protected withagsheet 4 of waxy paper or the (like .21;which.is readily peeled away just prior to assembly of the'accessory to a cable.

The means shown. in FIGS. -I,3 for. holding the split-ring... snugly clamped about a .cable of conductors 23,-. comprises a pair of .

clampingbands

24,25 of any wellknown-cornmercial type having their ends overlapping and adjustable relative tb. one another by rotation ofa

screw

26,27 having its threads engaged with short slotsformed crosswise of the clamping-band. It will be understoodthatany suitable type of clamping band:

may be employed.

Protecting the outer end of fitting 11 againstentry light weight noncorrosivemetal. In the lattercase, it maybe protected withan anodized or other suitable coating.

The installation of equalizer 10 will be readily apparen l from the foregoing description. First a small opening 3'7is formed inthe sheath 36.of cable 23. Desirably,.this openingli'sformed on the underside .of the cablesheath and is sized to receive theforward end 14 of fitting. 11. It is important that this end not protrude beyond the inner end of opening 37 as. thiscould interfere with or damage the electrical conductors enclosed by sheath-3.6.

The tackinessof plaque 20 aids very materially in holding the device inplace while the clamping .bands 24.25 are being inserted over the opposite lateral edges of ringlet 17. The clamp;

ing screws

26,27 are then progressively tightened pressing the layer of tacky material against thesheath andexpanding thisv materiallaterally until its outer edges lie substantially even with the adjacent edges of member 17. If thecup-shaped member 30 has notbeen assembled to threads 12, this is done, thereby completing the assembly operation. The central bore 40 through tubular fitting 11 is in freecommunication with the interior of the cablesheath andwith-the atmosphere through the downwardly opening shroudmember,30, Any change in pressure conditions between the interiorand exterior of the cable are immediately equalized through this passage and member 30.

Referring now to the modification-shown in FIG. 4, it is pointed out that this embodiment differs from the firstdescribed construction essentially in the use of athreaded nipple .42 to hold shroud member 30' to the internally threaded outer end of fitting -11. Otherwise, the two embodiments are constructed and installed in the same mannerand-their similar elements are designated by the same reference characters but distinguished by the addition of a prime.

Referring to FIGS. 5 and 6, there is shown a further simple embodiment of the invention, the same or corresponding ele.-- merits being designated by the same reference characters as the FIGS. 1=-3 but distinguished byathe addition of a double prime. A principal difference between the FIG. 3.and 4 and the FIG. 5 and 6'embodiment is that the split ring member 17' is provided with an attached adjustable take up means 26" so that its overlapping ends can be contracted to clamp device 10" securely to the cable. Although shroud cup 30 is shown of I moisture andforeign matter is a deepcup-shaped member .30 having a threaded opening- 31 in its bottom .mating with threads 12 of fitting llpThe shouldered interior side wall of member 30 supports fine wire mesh or other. foraminotrs, material 33 .heldinplace by keeper ring 34 and indentations. 35. Cup member 30may be molded of plastic or formedfrorn.

Still another embodiment of the pressure-equalizing accessory is shown in FlG. 7 and suitable for installation on cables 23" having a metal sheath. The tubular fitting interconnecting the cableand cup. 30" comprises an elbow 11" threaded at its opposite ends and preferably sealed to the cable sheath by solder 45 or a suitable adhesive. This embodiment may also be installed on cables having a plastic sheath using an adhesive to form a seal with the sheath. The elbow fitting 11" is installed inone side of a cable in the manner illustrated in FIG. 7 with the open end of shroud 30" facing downwardly. This mode of installation has advantages under certain operating conditions.

While the particular pressure-equalizing accessory for cables herein shown and disclosed in detail is fully capable of attaining the objects and providing the advantages hereinbefore stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention.

We claim:

l. A cable-pressure'equalizing accessory for safeguarding against a pressure differential across a cable sheath, said accessory comprising a tubular member having a wide radial flange spaced close to one end thereof, a seating gasket supported on said flange and adapted to seat against the exterior rim edge of a hole through .a cable sheath, split-ring-forming means embracing said tubular member and bearing against the opposite side of said flange from said gasket and adapted to encircle a cable sheath and including means for clamping said ring-forming means snugly against the exterior of a cable sheath, and a cup-shaped shroud member having an opening through the bottom thereof assembled to and in communication with the end of said tubular member remote from said gasket.

2. A pressure-equalizing accessory as defined in claim 1 characterized in that said split-ring-forming means is fixed to said tubular member and has said clamping means mounted thereon.

3. A pressure-equalizing accessory as defined in claim 1 characterized in that said cup-shaped shroud member is formed of anodized aluminum and includes means for holding the same detachably assembled to said tubular member.

4. A pressure-equalizing accessory as defined in claim 1 characterized in that said split-ring-forming means comprises a thin flexible metal strip having a thick wide plaque of tacky material on the face thereof adjacent said gasket strongly adherent to said metal strip and to a cable sheath when pressed thereagainst, and said clamping means embracing the opposite lateral edges of said metal strip being disposed to either side of said tubular member and adjustable to clamp said strip and said tacky plaque firmly against the exterior of a cable sheath with one end of said tubular member projecting into an opening through the wall of the sheath.

5. A pressure-equalizing accessory as defined in claim 4 characterized in that said plaque of tacky material has an opening therein sized to seat about the rim of said gasket.

6. A pressure-equalizing accessory as defined in claim 4 characterized in that said cup-shaped shroud member includes fine foraminous material extending crosswise of its interior effective to pass air but barring the passage of foreign matter.

Claims

1. A cable-pressure-equalizing accessory for safeguarding against a pressure differential across a cable sheath, said accessory comprising a tubular member having a wide radial flange spaced close to one end thereof, a seating gasket supported on said flange and adapted to seat against the exterior rim edge of a hole through a cable sheath, split-ring-forming means embracing said tubular member and bearing against the opposite side of said flange from said gasket and adapted to encircle a cable sheath and including means for clamping said ring-forming means snugly against the exterior of a cable sheath, and a cup-shaped shroud member having an opening through the bottom thereof assembled to and in communication with the end of said tubular member remote from said gasket.