Splice Case Assembly

Ance March 9, 1

Patent Grant 3569608

U.S. patent number 3,569,608 [Application Number 04/757,047] was granted by the patent office on 1971-03-09 for splice case assembly. This patent grant is currently assigned to Superior Continental Corporation. Invention is credited to Louis Ance.


United States Patent 3,569,608
Ance March 9, 1971
**Please see images for: ( Certificate of Correction ) **

SPLICE CASE ASSEMBLY

Abstract

Disclosed herein is a cable splice assembly in which a stripped end portion of the cable is enclosed in a plastic domelike container, said domelike container being in sealing engagement by means of a first type seal with a sealing chamber. This sealing chamber encloses not only the unstripped portion of said cable but also a plasticlike substance within a closed space to form a second type seal. Provisions are made for producing compressive forces on such plasticlike substance, to drive it thoroughly into engagement with the unstripped cable surfaces as well as the interior surfaces of the sealing chamber that encloses such plasticlike substance so as to produce a tight and gasproof seal of a second type against the unstripped cable surface and the inner surface of the sealing chamber enclosure. By means of such a two seal assembly, ready access can thus be had to the stripped cable portion through said first seal means without breaking the last mentioned seal.


Inventors: Ance; Louis (Hickory, NC)
Assignee: Superior Continental Corporation (Hickory, NC)
Family ID: 25046138
Appl. No.: 04/757,047
Filed: September 3, 1968

Current U.S. Class: 174/93; 174/76; 174/91; 277/621; 174/22R; 174/77R
Current CPC Class: H02G 15/013 (20130101)
Current International Class: H02G 15/013 (20060101); H02G 15/00 (20060101); H02g 015/08 ()
Field of Search: ;174/91--93,88,76,77,75,22,21,87 ;277/(Inquired),58,102,51 ;220/4

References Cited [Referenced By]

U.S. Patent Documents
707055 August 1902 Earl
2661120 December 1953 Miller
2996567 August 1961 Channell et al.
3148241 September 1964 Moore
3209069 September 1965 Ruddell et al.
3236934 February 1966 Revelle et al.
3422211 January 1969 Brisse et al.
Primary Examiner: Clay; Darrell L.

Claims



I claim:

1. A splice case receiving and protecting portions of cable sections comprising:

a. a domelike container wherein there is formed at an open end thereof an outwardly extending external face plate;

b. means defining a sealing chamber having two open ends, one end having formed thereon a face plate complementary with the face plate of said domelike container, said sealing chamber being formed near its other end with an internal annulus protruding inwardly from the internal surface of said sealing chamber and constituting an abutment, said means defining said sealing chamber being in removable, sealing engagement with said domelike container; and,

c. a composite formed of first, second and third spaced apart disc means all strung on a means adapted to move said first, second and third disc means in a closer relationship one to another, said first disc means being disposed on one side of said internal annulus, said second disc means being disposed on the opposite side of said internal annulus, said third disc means being spaced apart from said internal annulus and forming a compression compartment in combination with said second disc means and said sealing chamber, wherein said compression compartment contains a body of deformable sealing material, essentially filling said compartment, and each of said disc means having openings therein through which said portions of said cable sections extend, with said sealing material forming a seal around the portions of said cable sections extending through said compartment.

2. The splice case defined in claim 1 wherein the domelike container, sealing chamber, and each of said disc means are composed of polyvinyl chloride.

3. The splice case defined in claim 1, wherein the body of sealing material comprises a material which has a high internal molecular resistance, is deformable under compressive force, is substantially nonelastic, and is of a high viscosity.

4. The splice case defined in claim 3, wherein the sealing material comprises polyisobutylene.

5. The splice case defined in claim 4 wherein said sealing material is highly self-adhesive, and when portions of such material contact with each other under compressive forces, a substantially integral body of material is produced.

6. The splice case defined in claim 1, wherein the domelike container, said means defining sealing chamber, and each of said disc means are composed of a plastic material.

7. The splice case defined in claim 1, wherein the plastic material forming the sealing chamber is slightly adhesive to the body of said sealing material disposed in the compression compartment, and is more strongly adhesive to said body of said sealing material under shear.

8. The splice case defined in claim 1, wherein said means defining the sealing chamber and each of said disc means comprises polyvinyl chloride.

9. The splice case defined in claim 1, wherein an O-ring made of deformable material is disposed in U-shaped grooves formed in the face plates of both said sealing chamber and said domelike container to provide a seal therebetween.

10. The splice case defined in claim 1, wherein said means defining said sealing chamber is removably attached to at least one bracket means.

11. The splice case defined in claim 10, wherein said bracket means extend beyond a terminal portion of said sealing chamber and is removably engaged to at least one sheath of said cable sections.

12. The splice case defined in claim 1, wherein said means adapted to move said first, second and third disc means in a closer relationship one to another is a nut and bolt combination in engaging relationship, the head of said bolt being disposed on the outermost surface of said first disc means and said nut being disposed on the outermost surface of said third disc means, whereupon advancement of said bolt through said nut, advances said first disc means towards said third disc means.

13. The splice case defined in claim 1, wherein said openings in each of said disc means are of different diameter.

14. A cable splice case receiving and protecting portions of cable sections comprising:

a. a first cable portion receiving container having a first sealing means circumscribing an opening in said container; and,

b. a second cable portion-receiving container having a first opening circumscribed by a second sealing means, a second opening structured to receive a third sealing means, an annulus protruding inwardly from the inner surface of said second container, said second sealing means being in sealing engagement with said first sealing means of said first container and the third sealing means forming a composite formed of a first, second and third spaced-apart disc means strung on a means for moving said first, second, and third disc means in a closer relationship one to another, said first disc means being disposed on one side of said inwardly protruding annulus, said second disc means being disposed on the opposite of said inwardly protruding annulus and said third disc means being spaced apart from said inwardly protruding annulus to form a compression chamber in combination with said second disc means and the sidewall of said second container, said compression chamber containing a body of deformable sealing material, and each of said disc means having openings therein through which said portions of said cable sections extend, with said sealing material extending around the portions of said cable sections extending through said compression chamber.

15. The splice case defined in claim 14, wherein said first and second containers are composed of a plastic.

16. The splice case defined in claim 14, wherein said first and second circumscribing sealing means are complementary sections of an O-ring-type seal.

17. The splice case defined in claim 14, wherein the body of deformable material of said third sealing means has a high internal molecular resistance, is deformable under compressive force, is substantially nonelastic, and is of a high viscosity.

18. The splice case defined in claim 17, wherein the sealing material comprises polyisobutylene.

19. The splice case defined in claim 14, wherein said second chamber is removably attached to at least one bracket means.

20. The splice case defined in claim 14, wherein said first and second containers are composed of materials selected from the group consisting essentially of polyvinyl chloride, polyethylene, polypropylene, and polystyrene.
Description



DETAILED DISCLOSURE

This invention relates to cable splicers, and the like. The splice cases hereinafter to be disclosed have been designed especially to meet the rigorous and severe conditions to which such units are subject in normal and everyday use, and to meet other even more severe and rigorous conditions sometimes imposed by severe weather and temperature conditions. The splice cases herein disclosed have also been designed to accommodate and meet such conditions primarily where cables carry many pairs of conductors, either power or communications type-- including such cables as are presently being used in connection with telecommunications systems--for example coaxial lines or signal lines.

In the case of communication lines and other lines for such use as telecommunications, it is necessary to produce splices between successive lengths of the cable reel-ends, i.e. usually a few hundred or even a thousand feet of such construction, and in such a manner that current leakages or short circuits between the numerous pairs of conductors are avoided to a maximum degree. Not only is the splicing of such reel-ends necessary, it is also necessary in laying cable either above or below ground-- either unpressurized or pressurized--to splice into said cable between such reel-ends electrical apparatus such as loading coils and the like. Thus, the instant invention is concerned not only with splicing the ends of a reel of one cable to another, but also splicing into a cable between reel-ends additional apparatus necessary in making up a telecommunications system. Both of the embodiments of the instant invention avoid current leakages or short circuits between the numerous pairs of conductors. Furthermore, by use of the instant invention a saving of skilled labor, time expended in locating and repairing the defects, as well as losses due to "downtime" caused by such defects are achieved. There is assured, by means of the instant invention, near perfect transmission of the messages over each of the pairs, and avoidance of "crosstalk" between pairs. Aside from defects due to actual conductor contacts between the conductors of a pair or between conductors of proximate pairs, leakages may occur between such conductors, or between a conductor and ground due to the presence of moisture within the splice case unit. The presence of moisture within the splice case unit greatly magnifies troubles such as mentioned above, especially when the insulation on the conductors themselves is a paper product. The moisture, in such cases, readily finds its way through the insulation, due to capillary or similar water action. It is therefore imperative that maximum precautions be taken to avoid the presence of moisture within the splice case at and after the time of sealing the splice case; and above all, to provide a structure which shall, of itself, be practically impervious to incursion of moisture through elements of the splice case itself after sealing. Such incursions are largely due to successive changes in temperature conditions inside and outside of the splice case, such changes producing "breathing" which carries the moisture (water vapor in most cases) into the enclosed space of the splice case where condensation thereof takes place. Such conditions are aggravated proportionally to the lapse of time since the splice was completed, as well as the nature and severity of the weather to which the splice is exposed.

It will be understood, however, that the features of the instant invention hereinafter to be disclosed, are not limited to enclose splices made in existing lines overhead, but are also useful in the case of underground or buried lines and cables. In underground or buried lines of cables as well as aerial lines, the instant splice cases can be used in conjunction with either a pressurized or nonpressurized system. Furthermore, in underground systems natural electrical currents flow through the ground or other formations. These currents may greatly aggravate the deterioration of a metal splice case, especially when the cable is metal sheathed. In such cases the presence of different metals in contact with each other will cause production of local currents especially when water is present, and even more especially when there's water carrying one or more minerals in solution.

The recent introduction of cable sheaths formed of materials other than metal (e.g., various plastic material), largely eliminates some of the foregoing objectionable effects due to the use of metal sheaths, but it is also highly desirable to form the splice case itself of such a nonmetallic material, thus completely avoiding any electrolytic conditions at all. It is one of the prime objects of the present invention to provide a structure of such design and construction that all portions of a splice case may be formed of synthetic or plastic, nonmetallic materials, thus avoiding the objections already referred to in the case of metal splice cases. In this connection, there is also provided a splice case structure which may be, if desired, used in the joining together of proximate ends of lead or other metallic sheath cables, the elements of the splice case itself being completely devoid of any metal which could possibly produce or enter into an electrolytic and/or galvanic action.

The larger telephone lines, which have cables carrying 100 or more pairs, are conventionally provided with an inner and outer sheath or covering. The inner sheath may be of paper or plastic sheathing--the outer sheath being formed of material capable of withstanding the elements and physical encounters to which the cable may be subjected, including snow, sleet, ice, hail, etc. such outer sheathing is thus intended to protect the communication carrying lines against damage or physical encounters of severe degree. It sometimes happens, however, that such outer sheath is pierced, thus providing an entrance for water and water vapor. Even without a rupture of the outer sheath, water sometimes by osmotic pressure differential finds its way through such outer sheath and to the outermost surface of the inner sheath. This inner sheath is usually not made of material possessing the same or similar physical strength as the outer sheath but it is designed primarily to prevent entrance of moisture into the inner pairs. However, it seldom happens that such inner sheath itself is itself pierced, thus, it may retain its intended moistureproof characteristic. But moisture, admitted through the piercing of the outer sheath or otherwise, may arrive at the inner sheath notwithstanding, and then gradually move largely by capillary action, either lengthwise along the surface of the inner sheath to a location of lower pressure or into and through the inner sheath itself by osmotic movement. Furthermore, if in time such inner sheath loses much or even some of its moisture resisting characteristics, it too may become a path for free radial movement of such moisture inwardly, to the core--the location of the conductors.

It is one of the objects of the present invention to provide a splice case structure so constituted that when it is locked into its final place it will protect the junctions of the ends of the cable conductors and also form at least two different types of seals of high moisture resisting ability. The first of these seals is a positive seal between the surface of the cable's outer sheath and the inner surface of a portion of the splice case. Another but different type seal is an O-ring seal made between two flanged surfaces of a dome and main sealing or compression chamber, these two components making up the main portion of the splice case of the instant invention.

Consistent with the aforementioned object of the instant invention, the O-ring seal is so located that by breaking this seal, the dome portion of the splice case of an incoming cable and its pairs can be exposed where maintenance or construction work may be performed. This dome can subsequently be sealingly replaced without disturbing the integrity of the other seal operating around the cables coming into or leaving the splice case enclosure. Even a resealed dome develops such a strong seal that notwithstanding the fact that such a seal is broken a plurality of times, each and every resealing results in an airtight seal. Thus, the seal through which the incoming and out going cables or drop wires pass need not be disturbed when repair work in needed or additional cables added for any purpose. Since the last mentioned non O-ring-type seal is the most sensitive to the development of leaks therethrough, by providing an additional O-ring type seal that is readily restored in a quick and easy manner without fear of leaks developing through loss of seal integrity a most desirable combination is constructed.

Another object of the instant invention is to provide bracket means attachable to the external surface of the splice case, these means being so adapted as to provide mechanical support for arriving or departing sections of wire or cable. This support is attached at the splice case itself. One function of these support means (brackets) is to resist lateral displacement of the cable (as by bending) and thus preventing any disruption of lateral shift of the more sensitive non-O-ring-type formed between the outermost surface of the cable sheath and the innermost surface of the splice case container. Such a support means preserves the aforementioned seal even when there is swaying and swinging of the cable. Such motion usually results, in the absence of these supports, in a gradual grinding or deforming of the outer jacket and breaking of the non-O-ring seal integrity thereby producing leaks.

A further object of the instant invention resides in the provisions of a structure which lends itself admirably to production of many or all of its elements for molded, e.g. injection or extrusion molded, plastics or other readily formed and produced materials, especially from materials of a nonconductor (plastic) quality, In this connection it is a further object to provide a design of the various elements, such that they may be produced to a desired or predetermined tolerance and substantially without need of high cost machining or other finishing operations.

A further important object of the instant invention resides in the provisions of a splice case of such a construction that it will make possible the sustained existence of continuous air conducting ducts through the successive cables and the splice cases. This feature will be better understood from the following brief explanatory statement: Many multipaired cables have cores that contain gas under pressure. This pressurized gas aids in preventing incursion of moisture to the conductors, even when leads do occur at positions intermediate between successive splices-- that is, along the length of the cable itself. Such air pressure systems, when used, necessarily includes provisions for maintaining a supply of the compressed air (usually of a few pounds to above atmospheric) input at successive locations along the length of the cable. Such inputs may be many miles apart. Any minor leakage along such a length of cable will necessarily result in a small but significant flow of the air from the proximate input stations towards the point of loss. It is evident that such flow of air axially through the cable, small though it may be, requires flow through one or many of the splice cases present between such points of input. Accordingly, it is needful that the seals, which are provided at the junction of the proximate cable ends or at the points of junction of the proximate telecommunications additional apparatus (load coils) within a splice case, be of such form and so produced that they will not hinder the free exit of the moving air from one cable end, into the dome of the splice case, and from said dome of the splice case into the proximate end of the next cable section, it will be understood that such a slow flow or movement of the air lengthwise of the line of cable is possible through the inner core of the cable which is within an inner sheath. Air flow is possible because the core is formed of numerous pairs of lines, but its core construction is not solid to the extent sufficient to forbid such air flow lengthwise of the cable. To meet this condition, the seal contact with the cable itself obviously does not extend down into the pairs of the outer cable sheath. Such a seal is in contact only with the innermost surface of the splice case itself and the outermost surface of the cable sheath.

Another feature of the instant invention relates to an inherent provision of the disclosed structure in which the piece parts making up the composite splice case are of such a nature that when necessary the splice case may be readily opened and dismantled to the extent necessary to repair a broken pair, or a pair which may have become leaky or cross-connected to adjacent pairs, or to repair other damage while the splice case remains open. Such repair, as well as additional construction, can be carried out with substantial subsequent ability to restore such splice case to service under its original sealing ability, without any damage to such splice case itself or to its original seal contacting the cables involved. In other words, the instant splice case may be opened up and the cable and its pairs therein may be worked on by a workman--either for repair purposes or for further addition or construction-- and the case itself then subsequently closed without disturbing the seal between the cable carrying conductors outer sheath and the splice case itself. The ability to affect such emergency or nonemergency operations is enhanced by the nature of the splice case construction itself, including as one of its features two opposing face plates removable but sealingly secured one to another, the innerface created by the adjacent face plates being sealed from outside conditions by use of an O-ring-type seal.

A further important feature of the instant invention is a provision whereby a grounding harness connection is made between two cables just out-by the entrance of these cables into the splice case itself, this grounding means being electrically connected to an inner metal cable jacket which lies nested inside the outer plastic sheath of the cable. It is this grounding harness that maintains metal shield continuity throughout the cable trunk.

A further feature of the instant invention is a structure whereby a composite means is used to seal the outermost surface of the outer cable sheath to the innermost surface of the splice case itself, this composite being fixed and not free to move upon the application of varying mechanical, pneumatic, or gaseous pressures on the inside of the splice case itself.

The junction of the proximate cable ends within a splice case is of such form, and so produced, that there is no hindrance to the free exit of moving air from one cable end, into the body of the splice case, and the air while in the splice case can and does flow into the proximate end of the next cable section and thus out of the splice case via the cable. It will be understood that such slow flow of movement of the air lengthwise of the line of cable is possible through the inner core of the cable, within the inner sheath, since such core, formed of numerous pairs of lines, being not solid to the extent sufficient to forbid such air flow lengthwise. To meet this condition, the seal against the outer sheath of the cable, and the inner surface of the splice case itself is airtight. Thus, air traveling into the splice case by means of the cable sheath itself and therein being discharged into volume of the splice case is forced by the pressure built up in the splice case back into the proximate end of an outgoing cable length and thus into the core of said outgoing cable. Thus, the air flows lengthwise of the outgoing as well as the incoming cable.

A last, but not by any means least, feature of the instant invention is a structure whereby not only end portions of two different cables may be placed in a splicing means and spliced therein, but also additional cable stubs can be led into the instant splice case and electrically connected to the aforementioned two cable ends. Additionally, provisions are made for drop wires to be spliced to incoming and outgoing cables and to be let out through the splice case into appropriate installations or homes as the case may be. Furthermore, provisions are made to accommodate differing diameters of cables or drop wires notwithstanding a wide variance in diameter of drop wire cable or trunk cables used in actual service.

Other objects, advantages and features of the present invention will become apparent from the following detailed description, one embodiment which is present in conjunction with the drawings in which:

FIG. 1 shows an outside surface view of an assembled splice case embodying the features of the instant invention, the companion cable lengths joined together in the splice case, are shown broken off for the sake of convenience;

FIG. 2 shows a splice case with its dome removed exposing cable sections for ready access, splicing and/or maintenance;

FIG. 3 shows disc means strung on a bolt, this composite forming part of one of the seals of the instant splice case;

FIG. 4 shows the thus strung disc means of FIG. 3 assembled with cable portions and sealing tape laid adjacent to the cables to fill up unused or unwanted space in the holes of the discs;

FIG. 5 shows the disc means of FIG. 3 perspective, said disc means having more than just two complementary holes in each disc;

FIG. 6 shows the disc means of FIG. 4, along with an additional disc, assembled in a section surrounding of the sealing chamber of the splice case surrounding a deformable packing material not yet under pressure;

FIG. 7 shows a section view of the sealing chamber of FIG. 6 wherein the deformable packing is under pressure through the coaction of the discs, bolt, nut, and sealing chamber sidewalls. FIG. 7 also shows a locking of the aforementioned sealing composite to the sealing chamber itself through the compressive action of the composite sealing assembly;

FIG. 8 shows in perspective the basic components of the splice case depicting specifically the mode of assembly of the components to create an O-ring-type seal;

FIG. 9 shows a typical disc means of FIGS. 3 and 4 showing how an unwanted space is filled in the disc holes to accommodate various sized of cable diameters;

FIG. 10 is a front elevation of the disc of FIG. 9; and

FIG. 11 and 12 are perspective views of various types of plastic tapes used to accommodate cables of varying diameters in the disc holes shown in FIGS. 9 and 10.

Turning now to FIG. 1, numeral 1 indicates generally the overall assembly of the splice case as disclosed. Basically the splice case of the instant invention is made up of three basic portions: compression or sealing chamber 9, splice case dome 10, and a sealing means composite not shown in FIG. 1 because its normal assembled position is inside of compression or sealing chamber 9. The first two of these major components, i.e. compression chamber 9 and splice dome 10 are made out of plastic such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, and the like. Both the splice case dome 10 and compression chamber 9 have at least one complementary opening therein. At this particular opening there is a sealing means attached to or integral with both the compression chamber 9 and splice dome 10. Such is shown at 11 and 12. This sealing means is a conventional and well-known O-ring-type seal means employing two face plates 11 and 12, which are mirror images of each other. Both face plates 11 and 12 have a U-shaped groove disposed therein (not shown here, but see element 25 of FIG. 8) in which there lies an O-ring. This O-ring is made up of elastomeric (resilient) material. It is this O-ring-type seal means formed by elements 11 and 12 and its associated resilient O-ring that provides a ready means for access into the splice case without disturbing the sealing means that seals the surfaces of cables 5 to the inner surfaces of the sealing or compression chamber 9. One need only to loosen the bolt or fastening means 8 so as to permit removal of the dome splice case 10 from the sealing or compression chamber 9. Once this removal operation is performed, a stripped segment of cable--see element 14--is exposed as shown in FIG. 2.

Cable reel-ends or any portion between such ends are represented by elements 5. These cable portions are mechanically supported by bracket 3 and removably attached to cable 5 by clamp means 4. Bracket means 3 is secured to the compression chamber 9 by means of bolts 2. It will be noted that in FIG. 1, just out-by the terminal portion of the compression or sealing chamber 9, there is shown by element 6 a wrapping of tape around the cable portions 5. During the installation of the cables 5 into the assembly 1, cable sheath 5 is broken and the cable sheaths 5 peeled away to expose an inner metallic jacket or shield (not shown). A separate insulated electrical conductor 7, hereinafter referred to as a grounding harness, essentially a metallic conductor (not shown) surrounded by some form of electrical insulation such as a plastic. The metal means or conductor of the grounding harness 7 is attached to the metal shield of the cable 5 as the cable either goes into or comes out of, whichever the case may be, the splice case assembly 1. As a result of this grounding harness 7 being in electrical contract with the metal shield means of cable 5, a metallic path is created. Thus, the continuity of the cable metallic shield means is preserved from one reel end to another reel end or through any breaks in the cable 5 such as is shown in FIG. 2 by the exposed conductors 14 and cable 5.

As will be hereinafter disclosed and discussed, there is an additional (second) sealing means disposed inside of sealing or compression chamber 9. This sealing means terminates at one end generally near the attached end portion of bracket means 3 and terminates at its other end just in-by the terminal end of a compression chamber 9. This second sealing means, disposed on the inside of the sealing chamber 9, is one that crates a seal between the surface of cable 5 and the inner surface of sealing or compression chamber 9. Inasmuch as bracket means 3, acting in concert with cable clamps 4 and cables 5, hold cables 5 in a rigid predetermined and fixed position, any swaying, "singing", or vibration of cable 5 due either to wind movement or to manmade causes will not have a harmful effect on the seal between the cables 5 and the innermost walls of sealing or compression chamber 9. If such brackets were not used in the disclosed combination, the swinging and swaying of cables 5 would gradually erode and loosen the seal that seals the incoming and outgoing cables to the splice case inner surface.

Primarily what is shown in FIG. 1 is a hermetic splice case, which provides a volume in which there can be no entry of water, either liquid or vapor. The splice case is easy to install and after installation the cables therein are readily accessible to workmen who may need to repair or add apparatus thereto. Basically, a splice case of the instant invention as shown in FIG. 1, must maintain air pressure in order to exclude water or water vapor. Obviously, if it maintains air pressure within reasonable tolerances, then any water vapor existing in the outside ambient atmosphere will not find ready access to the interior of the splice case itself.

So as to achieve the above mentioned watertight splice case, use is made of a hole, in which plug 13 normally is disposed, during installation and/or after any reentry of the splice case assembly 1. This plug is a means used to fill up a small hole in the butt end of the dome splice case 10. The hole normally filled by plug 13 is used for the purpose of "flash testing" the splice case assembly 1. For example, once the instant splice case is assembled and attached to the cables as shown in FIG. 1, but before any form of superatmospheric pneumatic gas pressure is applied inside the splice case, a flash testing procedure takes place. This procedure entails the introduction of gaseous pressure to the inside of the splice case by means of the hole otherwise filled up by plug 13. Such a flash testing procedure detects leaks in the splice case before it is placed in its in-service condition (pressurized). Approximately 20 or 25 pounds p.s.i.g. are introduced into the splice case 1 through the hole normally filled by plug 13. Because of the constrictive air passages in cables 5, a temporary back pressure is created preserving much of the introduced 20 to 25 p.s.i.g. for a time used to test the splice case assembly 1 for leaks. To detect for such leaks one need only to "soap" down the outer surface of the splice case assembly 1 with a liquid containing a soaplike material. Any leaking air, if any, can thus be detected as bubbles will be formed by escaping air. Repairs can then be made to remedy such sources of leaks.

It is in the dome portion of the splice case, i.e. item 10, where stripped-away portions of cable 5 are disposed thereby exposing electrical conductors 14 as shown in FIG. 2. It will be noted from FIG. 2 that the cable sheath 5 extends through compression or sealing chamber 9 and partly into the dome splice case 10 before terminating and thus exposing the insulated electrical conductors 14. It is here in this volume created by dome splice case 10 where either reel-ends are spliced one to another or where electrical apparatus such as load coils and the like are introduced into a cable means either at or other than at the reel-ends. In other words, a length of cable can be cut at any predetermined or chosen point and inserted into the splice case of the instant invention. After removing a portion of the cable sheath 5 exposing electrical conductors 14, additional apparatus such as load coils can be spliced into the telecommunications system by selecting predetermined pairs and splicing in the aforementioned load coil. Load coil assemblies usually are made up with a predetermined length of cable stub attached to the load coil, and the load coil itself is usually encapsulated inside of a separate container. Either the entire encapsulated load coil assembly including its cable stub can be disposed outside of the splice case assembly or, in the alternative, the dome splice case can contain not only the encapsulated load coil assembly itself, but also its associated cable stub as well. Obviously if the encapsulated load coil assembly were not also encased in the dome splice case 10, then such coil assembly would either have to be buried along side of the splice case assembly 1, or placed in a housing. Such housings may be either flush with or below the soil surface. Furthermore, microwave amplifiers can be disposed inside the splice case dome and spliced into the telecommunications system through exposed electrical conductors 14, much as in the same manner as load coil assemblies can be spliced into a telecommunications trunk line.

Shown in FIG. 5 is a portion of a sealing assembly composite used to seal the outer surfaces of the cable sheath 5 to the inner surface of the compression or sealing chamber 9. Also shown in FIG. 5 is a plurality of discs 15 and 16, containing complementary holes of varying sizes 18 and 19, strung on a bolt means 14. Larger holes 18 are usually provided for cables of large diameter whereas smaller cables or drop wires can be led through holes 19. Cable sections 5 are inserted into holes 18 in both discs 15 and 16 much like that as shown in FIG. 4. in this particular embodiment there is shown two cable sections 5 along with bolt means 14 and discs 15 and 16. Usually the holes 18 are as large as the geometric area of discs 15 and 16 will permit. However, such is not always the case when different size cables are sought to be placed in the holes 18, i.e. the diameter of cable 5 may differ (be significantly smaller than) from that provided for in discs 15 and 16 by holes 18. That space not otherwise occupied by the cable 5 in hole 18 is generally filled up by a L-or tongue-and-groove-shaped tape means shown at 17. See also FIGS. 11 and 12. In FIG. 4 number 17 denotes an L-shaped tape means by showing a cross section thereof. Item 17 is a tape of indefinite length, which can be wrapped around cable 5 and the thus formed composite inserted inside of hole 18 in discs 15 and 16. These tape wrappings tend to fill up the majority of space not otherwise occupied by the cable 5 in holes 18. Such a taping technique could be used for small holes 19, in see FIG. 5. However, the smaller holes are normally provided for drop wire and as usually is the case the drop wire is of such a diameter that it virtually fills all of the volume represented by smaller hole 19.

FIG. 3 shows in section view the discs 15 and 16 strung on a bolt means 14 without the cable means inserted through the holes 18. Actually, there are three such discs making a sealing means composite used in combination with the cable 5 outer surface and the inner surface of compression or sealing chamber 9. However, for the sake of simplicity only two disc means are shown in FIGS. 3 and 4.

Bolt 14 as shown in FIGS. 3, 4, and 5 has a nut (not shown) threadedly engaged on its terminal portion. When said bolt 14 is rotated in a proper direction, disc means 16 and 15 are brought closer and closer together as a result. The second sealing means composite, previously made reference to and which is disposed on the inside of sealing or compression chamber 9, is made up primarily of cable 5, a sealing compound, and disc means 15 and 16. A sealing compound (preferably a polyisobutylene), which has a high internal molecular resistance, deformable under compressive force, is substantially nonelastic and of high viscosity as well as being highly self adhesive, and possess the characteristic that when portions of such material contact with each other under a compressive force a substantially integral body of the material is produced, is generally disposed between discs 15 and 16. As stated previously, the second sealing means composite is disposed on the inside of sealing or compression chamber 9. This second sealing means is a composite, which in its entirety is composed of at least two of the disc means 15 and 16 plus an additional disc, the cable sheath 5, the polyisobutyl plastic 21 disposed between discs 15 and 16, an internal surface of sealing or compression chamber 9 shown by the numeral 22, and internal shoulder means noted by number 23 in FIG. 6. All of the aforementioned units act in concert with each other to form the compression seal.

Turning now for description of such a sealing composite, attention is directed to FIGS. 6 and 7 where it can be immediately appreciated that the sealing or seal composite, previously mentioned, is placed inside of the sealing or compression chamber 9 with the stripped portion of cable 5, exposing electrical conductors 14, being extended outside of the compression or sealing chamber 9. In FIGS. 6 and 7 it can be immediately noted, in contradistinction to FIGS. 3 and 4, that there are shown three disc means, elements 15, 16, and 20. In FIGS. 6 and 7, a first disc means 15 is disposed on one side of and inwardly protruding shoulder means 23 and still another identical disc means 20 is shown disposed on the opposite side of said shoulder means 23. This shoulder means 23 is used primarily to fix or anchor the sealing composite in a predetermined or fixed position inside of the sealing or compression chamber 9. The reason for this fixation will become apparent hereinafter in more elaborate detail. A third disc means 16, like unto that disc means 15 and 20, is disposed in a spaced part relationship from the internal shoulder means 23. Between disc 16 and 15 there is disposed packing material 21, which is normally a polyisobutylene or B-sealing tape.

In FIG. 6, which shows the sealing composite made up of discs 20, 15, and 16 strung on bolt means 14 associated with cable 5, there is also shown a packing material 21. The composite with the packing material 21 is loosely laid into the sealing or compression chamber 9 as shown in FIG. 6, with the discs 20 and 15 disposed on their respective sides of inwardly protruding shoulder means 23. Upon rotating bolt means 14 or its associated nut 14a in a manner such that disc means 20, 15 and 16 are brought closer together, the packing material 21 is compressed. This compressive action forces, in a sandwichlike fashion, disc 15 to the left and against shoulder means 23. Concomitantly with this compressive force, disc 20 is moved to the right and it too engages shoulder means 23, but on an opposite side thereof. In effect then, shoulder 23 acting in concert with discs 20 and 15, bolt means 14, and interacting with the packing 21, which is being placed under a compressive force, anchors the disc 20, shoulder means 23, disc 15 in a sandwichlike construction to the sidewall of compression or sealing chamber 9 by biting action on shoulder means 23. The sidewall innermost surface of compression or sealing chamber 9 has a nonsmooth surface. That is to say, there is no need to have the innermost surface of sealing or compression chamber 9 finely machined or smooth for any purpose. In fact, during the molding of sealing or compression chamber 9, the innermost surface of this particular chamber is purposely roughened, knurled, scratched, or otherwise rendered nonsmooth so that the packing material 21 will have engaging crevices in which it will intrude and perfect the desired seal between the sealing compound 21 and the sidewalls of sealing or compression chamber 9. In like manner, the cable sheath 5 may also be roughened, nicked, or scratched--but in no manner completely penetrated--so as to form a rough surface into which the sealing material 21 may intrude and perfect a seal between the innermost innersurface of sealing or compression chamber 9 and the outermost surface of the cables 5.

FIG. 6, as previously stated, shows the sealing composite loosely laid on the compression or sealing chamber 9 as a first step towards complete assembly. On the other hand, FIG. 7 shows the sealing composite under its compressive force brought about by bolt 14 acting in concert with its corresponding nut 14a shown in both FIGS. 6 and 7 on the lefthand terminal portion thereof. One immediately will observe that discs 16, 15 and 20 have been brought in a closer relationship by the rotation of bolt 14 and its complementary or corresponding nut 14a on its opposite side. Furthermore, it will also be noted in FIG. 7 that the discs 20 and 15, disposed on opposite sides of shoulder means 23, actually place shoulder means 23 in compression. As previously mentioned, this compressive force or biting action actually acts as an anchor which fixedly positions the sealing composite, shown in FIG. 6 and 7, to the sidewalls of the sealing or compression chamber 9. The packing material 21 shown in FIG. 6 is essentially a tape or bits and pieces, either granular or strips, of what is known in the sealing trade as "B-sealing tape." This sealing tape is normally a polyisobutylene and has the characteristic of being highly self-adhesive when portions of such material contact with other portions under compressive forces. As previously noted, materials suitable for use as a sealing compound would naturally have to have a high internal molecular resistance, be deformable under compressive force, substantially nonelastic, and possess a high viscosity. Most, if not all of the polyisobutylenes possess such properties. Viewing now FIG. 6 in comparison with FIG. 7, one will note immediately that the packing material 21 here at this stage of assembly is composed of substantially integral, discreet elements, whereas after compressive forces are added as depicted in FIG. 7, the resinous polyisobutylene is essentially homogenous, possessing no discreet particles at all. This is shown in cross section as 21a. In FIGS. 6 and 7, disc 20, 15, and 16, as well as the cables 5 were not shown in cross section for the sake of simplicity and to avoid confusion. Whereas on the other hand, in FIG. 6, the packing material 21 was not shown in cross section because when this packing material is initially introduced into the composite sealing assembly previously described, it is particulate in nature and not yet integral. However, on the other hand, one only needs to observe FIG. 7, especially that element denoted by numeral 21a to understand that the packing material 21 in FIG. 6, after having been subjected to compressive forces, is compressed and made integral with all of the particulate particles heretofore unjoined and discreet as shown by element 21. It will be further appreciated that the innerface created between the contacting surfaces of discs 15 and 16 with the innermost sidewalls of compression or sealing chamber 9 are not exactly airtight, absent the polyisobutylene or sealing material 21 or 21a. However, upon compression of the polyisobutylene material 21 into its integral state as shown in 21a, the polyisobutylene tends to intrude into the innerface created by the contacting surfaces of discs 15 and 16 and the innermost sidewalls of compression or sealing chamber 9. This intrusion into this specified innerface creates an airtight seal, thus keeping out all water vapor and other unwanted gases as well as water in the liquid state.

One feature of the instant invention upon which there cannot be placed too much emphasis is the fixing means or anchoring combination created by the coacting elements of discs 20, 15 and shoulder 23. Although a perfectly usable and viable sealing means can be created using only discs 15 and 16, absent any disc 20 or shoulder means 23, such a sealing combination is subject to being disturbed by subsequent high levels of gaseous pressure being disposed against disc 16 and acting in a manner in which said disc 16 would be urged in a leftward manner. It has been previously pointed out, during the discussion of FIG. 1, the primary function of plug means 13 disposed in the dome splice case of the instant invention. When 20--25 lbs. p.s.i.g. are introduced into the splice dome 10 through the hole occupied by plug means 13, this particular high amount of pressure is obviously applied against disc means 16. This pressure subsequently urges the disc means 16 in a leftward manner. If it were not for shoulder means 23, then it would be quite possible under certain circumstances that the composite lying between disc means 16 and disc means 15 could be moved in its entirety in a leftward fashion. Such movement would obviously disturb the integrity of the thus formed seal and invite the leakage of air, water, and water vapor from outside of the splice case to the inside.

The foregoing discussion shows how seal integrity can be disturbed when there is no shoulder means 23 such as that shown in FIGS. 6 and 7. Thus, the seal integrity is important so as to insure the exclusion of moisture from the splice case itself or the loss of air pressure from within the splice case to the outside ambient atmospheric pressure. Wheat has been previously described is the loss of seal integrity by moving the composite from an original sealing position in a leftward manner. Obviously if the original seal is moved in a rightward fashion the sealing integrity is also broken and the same invitation to moisture entrance is initiated. Thus, it is quite obvious that neither leftward or rightward movement of the sealing composite is desired. Absent disc 20 and inward protruding shoulder means 23, the sealing composite made up then only of discs 15 and 16 are associated components could then be moved in a rightward fashion by an intentional or even an inadvertent force acting on disc 15 and emanating from outside the sealing or compression chamber 9. Consequently, the anchoring or fixing action of discs 20 and 15 biting or compressing shoulder means 23 anchor the sealing composite in a fixed, but nonetheless removable, position inside the sealing or compression chamber 9. By this anchoring action, the sealing composite may move neither to the left nor to the right, thus maintaining complete seal integrity between the composite sealing means and the innermost surfaces of sealing or compression chamber 9.

Turning now to FIG. 8, there is shown in this delineation the coaction between O-ring 24 and face plates 11 and 12 with the associated U-shape groove 25. It is to be understood that the U-shaped groove 25 is not a singular groove being only in face plate 11, but has a counterpart in faceplate 12. In the well-known manner, O-ring 24 lies partly in groove 25 and a corresponding U-shaped groove in faceplate 12 when the faceplates 11 and 12 are joined in a seating engagement as shown in FIG. 1.

The O-ring used in the instant invention obviously must be an O-ring of outstanding sealing properties. Ordinarily, just any kind or elastomeric material would not be appropriate for the temperatures that are anticipated to be encountered when the splice case is underground or in buried service. However, generally speaking the O-ring 24 can be made out of most any kind of silicone rubber. Specifically, however, any silicone rubber that possesses the specifications and qualities of military specification 58470 (MIL-R-58470) and/or Aeronautical Material Specification 3303E (AMS-3303E) would be sufficient for practical purposes. The O-rings used in the instant invention not only live up to and conform to the aforementioned government specifications but were purchases on the commercial market from Prevision Rubber Products bearing the catalog number 113076.

Still focusing attention on FIG. 8, there is shown in this particular FIG. in the upper right-hand corner thereof, three cables all identified by the numeral 5. Furthermore, these cables are shown, deliberately so, as cables of varying diameters. For the sake of clarity and delineation in the instant drawing, the associated continuing portions of cable 5 as they would obviously extend through the compression or sealing chamber 9 through O-ring 24 and terminate in the dome splice case 10 are not shown. FIG. 8 should be viewed along with FIG. 5 because the combined teachings of these FIGS. are used to point out that not only cables of a singular diameter can be used in the instant splice case but also cables of a number higher than two and of all varying diameters. FIG. 5, as it will be remembered, shows three large holes 18 in the disc means 15 and 16. Also three smaller holes indicated by the numeral 19 are also shown in discs 15 and 16. Normally, cables of larger diameter occupy the holes indicated by the numeral 18 whereas on the other hand drop wires or cables of a much smaller diameter are led out of he splice case through holes 19. If holes 19 are not desired to be used when the splice case is being installed, then the sealing composition identified as polyisobutylene can be used to fill these holes and prohibit the entry of air or water vapor into the interior of the splice case. Obviously, the filling of small holes 19 is accomplished by the compressive force being applied to discs 15 and 16 and thus transferred from these discs to the packing material (polyisobutylene) initially shown as uncompacted in FIG. 6 by numeral 21 and ultimately shown as compacted and in sealing engagement in FIG. 7 as item 21a.

It is envisioned that one may take advantage of smaller holes 19 by employing foresight when the splice case is being installed. If at the time of splice case installation there is no immediate need for any drop wires to be spliced into the cable and let out of the splice case into the installation nearby, but, there may be some reasonable expectation that in the somewhat distant future that such a need may occur, a length of drop wire may be installed for just such a purpose in the manner that will be described. Taking a length of drop wire long enough to extend from the exposed electrical conductors 14 out of the splice dome case into the sealing or compression chamber 9 and out of the chamber 10 into the surrounding atmosphere for a predetermined length and then returned by a parallel path, this wire is looped in a fashion to where the two ends are brought in side-by-side relationship. Thus, a loop is formed. Still maintaining the loop configuration thus made, the two ends of the wire are pushed through two different holes 19 in disc 15 and corresponding holes in disc 16 as well as disc 20 as shown in FIGS. 6 and 7. The loop thus threaded in the aforementioned disc is then pushed further bringing the side-by-side ends of the loop closer and closer to the exposed electrical conductors 14 as shown in FIG. 2. When the ends have been extended far enough to where they can be and are spliced into appropriate electrical conductors 14, then the thus looped and spliced in wire is ready for final assembly in the same manner as the cables 5. This manner of sealing is the same as that shown and described in previous discussions relating to FIGS. 6 and 7.

After following the foregoing procedure the resulting assembly has a loop of wire extending from the compression or sealing chamber 9, one portion which comes out of the sealing chamber and the other end naturally going back into the sealing chamber. Both ends of this loop, as previously discussed, extend into the splice dome 10 where the ends of the wire are spliced into appropriate electrical conductors 14 as shown in FIG. 2. Also in this assembly there extends from the compression chamber 9 cables 5 in the same manner as that as been previously discussed. Consequently, when there is a need for a drop wire service, a workman need only dig up the splice case--if indeed the splice case is buried--cut the loop formed during initial installation thereby creating two drop wire stubs. Either one or both of these stubs may be used, whichever the case may be. Obviously if only one stub is used then the terminal end of the unused stub should be sealed up with sealing tape or encapsulated with an epoxy as is well known. Such a procedure forms no part of the instant invention and will not be further discussed. In the same manner, a looped cable stub--that is a cable carrying a multiplicity of pairs--can be installed with the splice case much in the same manner as that previous description running to the drop wire loop. Obviously, neither one of these loops of cable or drop wire are in immediate service but can be placed into service by a very simple expedient of cutting and resplicing employing unskilled labor.

The advantage of the foregoing looping of either drop wire or cable in the manner just disclosed is that no disruption of the seal existing between cable or wire outer surfaces and the innermost surface of compression or sealing chamber 9 is necessary to activate the looped wire or cable. Once this seal is achieved, it is better practice not to disturb its integrity as it is this seal that is the most sensitive to the possibility of leaks of both air and water vapor.

Attention should now be focused on FIG. 9 wherein there is shown a disc means 15 having eight holes therein. In this particular FIG. the disc means is shown as 15, but it will be understood that discs 16 and 20 would also be of like configuration. As it has been previously noted, the larger holes 18 in disc means such as 15 are normally used for cables carrying a multiplicity of electrical conductor pairs. It has also been previously stated that the manufacture of disc means 15 with the holes 18 therein, must encompass a procedure whereby the largest hole possible is formed in disc means 15 as shown by the numeral 18. Of course the overall design (size) and number of holes 18 and 19 are commensurate with the physical strength necessary for disc means to carry out its intended function. Nonetheless, consistent with the foregoing structural requirements, holes 18 are designed to carry the largest cable anticipated to be used for a particular splice case. Obviously this does not prima facia take care of or account for the use of cables that have a diameter smaller than that of the hole 18. To take care of this possibility, a "taping" of the hole 18 is used in order to take up the space not otherwise occupied by the cross-sectional area of the cable that is used and disposed in hole 18.

Once a determination is made that the cable used in holes 18 will be smaller than the holes 18, then tape 25 as shown in both FIGS. 9 and 10 is used to take up the space not otherwise occupied by the cable in hole 18. This tape is usually a plastic tape and it can be made out polyvinyl chloride. Polyvinyl chloride is given as an exemplary only and is not to be construed as limiting because the tape obviously can be made out of polyethylene, polypropylene, polystyrene and the like. Also, such a tape can be made out of elastomeric material such as silicone or natural rubbers. In essence the tape 25 is made into a washer or a packing that merely takes up space and tends to lock itself into mechanical engagement. It also can and does help contain the sealing material (polyisobutylene) which it disposed on one side of the disc 15. In FIGS. 9 and 10, the tape used here is an L-shaped tape. Each revoultion--shown as 25a and 25b--is cut so that terminal end portions abut one another and essentially create an entire revolution forming a gasket or washerlike insert. Such a revolution as shown in 25a and 25b are inserted into the holes 18 until there is enough space taken up by the tape that the cable passing through the reduced diameter of the hole will be in touching engagement with the innermost surface created by the tape 25 gasket or washerlike configuration.

Attention is called to the assembly as shown in FIG. 10 where the tape, as previously mentioned, more clearly shows its L-shape. Number 26 shows one leg of the L-shaped portion whereas number 27 of the tape more or less indicates the shank portion or other leg forming the L-configuration. Obviously, tape 25b is also of the same shape since its shank portion is fully extended and the flange or horizontally protruding L-forming portion of this particular tape being flush with the proceeding tape. Tape 25b's particular overall L-shpaed configuration is not shown as well as its preceding tape 25a, this latter tape configuration being indicated by the numerals 26 and 27. FIG. 10 completes the disclosure of how the tape is used in combination with cable 5 and disc 15. Viewing this FIG., one can see how the disc 15 acts in concert with the space occupying tape 25 with the cable nesting inside of the individual revolutions of tape 25. In passing, it might be well to note that ordinarily the space occupying tape is not usually used in combination with drop wires and smaller holes such as 19. However, this is not to say that the tape is never used with such smaller holes, the use of this tape being dependent largely on the size of hole, the size of the cable to be disposed in the hole, along with the overall economics of the splice case installation method.

In further amplification of the specific plastic tape discussed above, attention is drawn to FIGS. 11 and 12. In these two FIGS. two different embodiments of the aforementioned tapes are shown. The first embodiment, is shown in FIG. 11. This embodiment is the previously mentioned L-shaped tape and its L-shape cross section can be readily appreciated from this particular FIG. The second embodiment of the tape employed is shown in FIG. 12 which is not an L-shaped tape. This tape is a tongue-and-groovelike tape as shown by its characteristic cross-sectional configuration with the tongues on one side of the tape being complementary and fitting into the grooves on the opposite side of the tape. Thus, it can be readily appreciated that a revolution of such a tape nesting inside of a tape made of the same material can be used to form a tongue and groove seal. As a result of the tongue-and-groove configuration on both sides of the tape, the outermost surface of the first revolution would be in complementary engagement in a tongue-and-groove fashion with the innermost surface of the second tape revolution. Experience has shown that it makes no difference which one of the particular tape embodiments is used, i.e. tongue-and-groove or L-shaped tape. The tongue-and-groove embodiment is just as efficient as the L-shaped tape. Thus, the use of either one is arbitrary and a mere matter of choice.

From the foregoing disclosure one can be readily appreciate that there has been described a splice case of novel and unusual characteristics that meet the needs currently plaguing the telecommunications industry. Presently, this is the only known splice case that has been able to stand the rigorous tests of the Rural Electrification Administration identified as Phone Equipment (PE) 70 (1967). There is no other known test, either ASTM or otherwise that is designed to test the viability of splice cases adapted to be used in conjunction with a pressurized telecommunications system. The forementioned REA PE 70 test is one that requires that a self-contained splice case be charged with at least 25 p.s.i.g. air pressure. What is meant by self-contained is that the cables used during this test create a short circuit. That is to say, any cables led out of a splice case are immediately looped around and brought back into the same splice case. A splice case thus assembled, and charged with the necessary internal pressure of 25 p.s.i.g. is then put through 50 cycles of severe temperature changes. A cycle is defined as four clock hours at -40.degree. F and then while at that temperature, the cold splice case is plunged into an oven set at 140.degree. F and maintained at that temperature for four hours. After 50 of the above described cycles have been completed, a test is made to determine how much air pressure still remains inside of the splice case. The Rural Electrification Administration requires tat a minimum of 4 p.s.i.g. must remain inside of the splice case at the end of the 50 cycles. That is to say, if after the forementioned 50 cycles, a splice case still contains 4 p.s.i.g. of pneumatic pressure, then it is to receive the seal of approval from the Rural Electrification Administration. When the instant splice case was put through its paces using the REA PE 70 (1967) splice case testing procedure as previously described, the amount of air pressure left inside of the splice case after the 50 cycles was not 4 p.s.i.g. but two times the minimum required for satisfactory approval by the Rural Electrification Administration. In other words, after the 50 cycles the instant splice case exhibited an 8-pounds per square inch gauge internal pressure. Obviously, there was a loss of 16 p.s.i.g. during the 60-cycle testing procedure. It is anticipated by both the Rural Electrification Administration as well as those in the industry that cable sheaths currently being used in telecommunications system are the prime source of air pressure loss. It is thought that the pressure is lost through the cable sheaths by osmotic action. Since the temperatures encountered by the splice case assembly and the cable looped into and out of the splice case are rather severe, i.e. -40.degree. F to +140.degree. F, there is a definite osmotic effect which argues for the escape of gases from the pores of the cable sheath. This kind of osmotic effect is known in the telecommunication pressurized industry, and this phenomena was built into the Rural Electrification Administration's test devised for splice cases. That is to say, there was expected to be a pressure loss from the original 25 p.s.i.g. introduced into the splice case. In retrospect, one can see that there was to be an expected loss from 25 p.s.i.g. down to 4 p.s.i.g. Such a loss of 21 pounds during the cycling period was considered by the Rural Electrification Administration to be normal and to be anticipated through the forementioned osmotic effect. Thus, even a 21-pound loss would still render a splice case suitable for Rural Electrification Administration's approval. Almost in contradistinction to the expectancy of the Rural Electrification Administration Phone Equipment test 70, the instant splice case had a residual pressure of 8 p.s.i.g. and lost not 21 pounds during the cycling process but only 17 p.s.i.g.

One feature of the instant invention that has not been discussed is the effect of the compression seal which seals the outermost surfaces of the cables of the splice case assembly to the innermost surface of the compression or sealing chamber 9. When it is realized that the cores of most cables contain electrical conductors that are also covered with an extruded covering of plastic insulation, it can be anticipated that such a plurality of electrical conductors--otherwise known as pairs--may cross one another. That is to say, one electrical conductor may physically lie across the path of another electrical conductor or a plurality of electrical conductors for that matter. When compression is created by bringing discs 15, 16, and 20 closer and closer together and thereby putting polyisobutylene 21 under compression, this compressive force is correspondingly transmitted from this polyisobutylene material to the cable sheath 5 and obviously into the core of the cable. Initially, it was feared that such a continued, long sustained, and high compressive force would be of such a nature that "cold flow" of the plastic surrounding the electrical conductors in the core would take place. If cold flow would take place as a result of this compression, then the insulation surrounding the electrical conductors would be reduced at the point where one electrical conductor contacted (crossed) and adjoining an electrical conductor. This cold flow phenomena was not observed in the cables used in designing the instant splice case invention. It may be said in speculation that the compressive forces generated by the sealing means composite in the sealing or compression chamber 9 is of such a magnitude to accomplish the job of sealing the cables to the innersurface of the sealing or compression chamber 9 without transmitting the necessary cold flow forces into the interior of the cable 5. Thus, in the absence of any cold flow of the insulation surrounding the particular electrical conductors in the core of the cable, short circuits, attenuation loss, and crosstalk are virtually eliminated.

Viewing the foregoing disclosure in its entirety, one can come to the conclusion that the instant disclosure sets forth a splice case assembly of unique and outstanding features. Other innovators in this particular field, namely, G.E. Peterson, in his patent disclosure 3,381,082 (C1.174--93) approaches the same problem as the instant disclosure in a radically different manner. As with Peterson as well as other investigators in the particular area of concern, no provision whatsoever was made for reentry into the splice case without disturbing the compression seal formed in a chamberlike compression or sealing chamber 9. The prior art all requires that reentry into a chamber containing conductor pairs must be accomplished by breaking the compression seal and thereby disturbing its integrity. The only other way one could achieve entrance into a chamber containing conductor pairs without breaking the compression seal would be to actually destroy the splice case itself by a cutting operation. Obviously this cutting operation is undesirable as is the breaking of the compression seal. Thus, it can be immediately appreciated that the instant invention discloses a splice case assembly that permits ready access to a chamber that contains the conductor pairs without disturbing a seal that seals the outermost surface of the cable surfaces to the innermost surface of the splice case itself. The instant invention requires only that an O-ring-type seal be broken so as to expose the conductor pairs. Once the conductor pairs are exposed, then work can proceed in any manner desired for any purpose required. Once such work is completed the O-ring-type seal can be reactivated using the same O-ring that was previously installed with the splice case itself, the sealing tested and the splice case placed back into service without any disturbance of the seal between the cable surfaces and the splice case sealing or compression chamber 9 inner surface. Consequently, using this particular structured splice case has many unique advantages over that of prior art splice cases. Furthermore, prior investigators, such as G. E. Peterson, have all used a threaded seal and attempted to extend this threaded seal concept to plastic splice cases. As is commonly known, threaded portions on plastic structures are not well adapted to maintain seal integrity, especially seal integrity of the high order required in pressurized splice cases. It will be immediately noted that there is no such threaded seal concept in the instant invention, the sealing concept used in the instant invention depending entirely on compression which lends itself admirably to the basic structural strength of plastic materials.

From the foregoing, it is believed that the invention may be readily understood by those skilled in the art without further description, it being borne in mind that numerous changes may be made in the details disclosed without departing from the spirit of the invention as set forth in the following claims:

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