A method and apparatus for sealing a splice enclosure to protect cable splice connections retained therein. The sealing member is a single piece body integrally formed of a suitable material which resists detrimental environmental effects and is resiliently compressible in an axial direction to seal the splice enclosure. Axial compression of the sealing member is employed to create sealing forces both about the outer periphery of the sealing member and between the sealing member and cables projecting therethrough. Reentry into the enclosure does not require destruction of the sealing member and does not require tapes, adhesives or other materials and is hence very time, labor and material efficient.

BACKGROUND OF THE INVENTION 
This invention relates to the splice enclosure arts and more specifically 
to an apparatus and method for sealing splice enclosures. 
Dependency upon telecommunications and data communications presses the 
technology to provide consistent high quality communications with minimal 
down time. A key to providing high quality communications with minimal 
down time is to protect installations at critical points and provide for 
quick and efficient in-field repairs. 
In the communications field it is common to install multi-carrier primary 
cables to provide communication service to a predetermined area. The 
primary cable, consists of perhaps approximately 100 individual binder 
groups of multiple wire pairs. 
At specific points along the primary cable, connections must be made to 
route individual wire pairs to end user locations. Primary cables are 
typically very long continuous cables and are not conveniently 
manufacturable with specific service cable lengths at predetermined break 
off points. In this situation, it becomes necessary to extract specific 
binder groups from the primary cables and to splice these wire pairs to 
service cables which are then routed to the end user locations. 
The splice connection between the service cable and the primary cable wire 
pairs must be protected from the environment in which it is installed, 
since moisture, oxygen, temperature, and the accumulation of dust and dirt 
or chemicals may individually or cumulatively act to the detriment of the 
splice connections. Typically, prior art splice encloses protects a 
portion of primary cable and the splice connections in a so-called dome 
enclosure. The dome enclosure is an elongate sleeve-like structure having 
a closed end and an open end through which the primary cable and service 
cables are inserted and from which these cables project. To protect the 
primary cable and the splice connections from detrimental environmental 
effects, the open end of the dome enclosure must be sealed. 
Current dome enclosure sealing technology has problems which must be 
overcome to improve telecommunications quality and minimize down time for 
repairs. For example, a typical prior art sealing arrangement which seals 
the opening formed in the dome enclosure must be individually fabricated 
for each installation which is to be sealed. The sealing arrangement is 
fabricated by repeatedly wrapping tape-like material around the cables 
projecting through the opening and then inserting the wrapped cables in 
the opening. The dome enclosure then employs some form of circumferential 
constricting apparatus to circumferentially compress the wrapped cables to 
enhance the seal. 
This type of prior art sealing arrangement is complex and time consuming to 
assemble and unnecessarily lengthens down time for installations and 
repairs. The problem is exacerbated when a repair or modification is 
needed to the splice connections since under the circumstances the sealing 
arrangement must be severed and removed and a new sealing arrangement 
re-constructed. This type of prior art sealing arrangement and method 
unnecessarily wastes time and valuable resources. 
A specific example of a prior art enclosure and sealing arrangement is the 
PST pedestal splice closure manufactured by 3M, TeleComm Products 
Division, Austin, Tex. This arrangement is also shown in U.S. Pat. No. 
4,902,855 to Smith. In this prior art splice enclosure, the cables are 
inserted into a dome enclosure and the open end is sealed. A sealing 
arrangement is formed through the tape wrapping method described above. 
This method forms a seal which is inherently non-uniform thereby creating 
potential for problems with the fit inside of the dome member and/or any 
circumferential compression fitting or clamp used to engage and seal the 
structure. Further, depending upon the type of tape used, the ground wires 
may have to be separately wrapped prior to incorporation into the common 
seal. The sealing arrangement as formed is then inserted into the open end 
of the dome enclosure and a shrink tubing is positioned and shrunk around 
the outside of the dome to retain the sealing member therein. Alternately, 
a clamp may be used, as shown in the above-mentioned '855 patent. 
As mentioned above, this type of prior art sealing system is inherently 
extremely time consuming and material intensive. Further, this system 
risks cutting or otherwise damaging cable jackets in attempting to remove 
the shrink tubing as well as the sealing member when repairing or 
modifying splice connections. Additionally, sufficient supplies such as 
tapes and shrink tubing must always be on hand or further delays due to 
lack of supplies may result when installing or repairing splice 
connections. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a reusable and easily 
reenterable splice enclosure for protecting splice connections made to a 
primary cable 
Another object of the present invention is to provide a sealing apparatus 
and sealing method which facilitates ease of access to the splice 
connections for providing efficient access and resealing of the splice 
enclosure. 
A more specific object of the present invention is to provide a splice 
enclosure sealing member which is axially compressed to create sealing 
forces between an opening in a dome enclosure and cables projecting 
therethrough. 
Briefly, and in accordance with the foregoing, the present invention 
comprises a method and apparatus for sealing a splice enclosure to protect 
cable splice connections retained therein. The sealing member is a single 
piece body integrally formed of a suitable material which resists 
detrimental environmental effects and is resiliently compressible in an 
axial direction to seal the splice enclosure. Axial compression of the 
sealing member is employed to create sealing forces both about an outer 
periphery of the sealing member and between the sealing member and cables 
projecting therethrough Reentry into the enclosure does not require 
destruction of the sealing member and does not require tapes, adhesives or 
other materials and is hence very time, labor and material efficient.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
While this invention may be susceptible to embodiment in different forms, 
there is shown in the drawings and will be described herein in detail a 
specific embodiment of the present invention with the understanding that 
the present disclosure is to be considered an exemplification of the 
principals of the invention, and not intended to limit the invention to 
the embodiment illustrated and described herein. 
It should be noted that dimensional relationships between members of the 
illustrated embodiment may vary in practice or may have been varied in the 
illustrations to emphasize certain features of the invention. 
As shown in FIGS. 1 and 2, a splice enclosure 20 is illustrated comprising 
a dome member 22 and sealing means 24. As illustrated in FIG. 1, a primary 
cable 26 has a looped portion 28 extending into the splice enclosure 20 
through the sealing means 24. The primary cable may be any type of cable 
including, but not limited to; copper telecommunications cable, fiber 
optic cable as well as power cables. A portion of a cable jacket 30 is 
removed from the looped portion 28 to expose multiple binder groups 32 
which comprise the primary cable 26. Splice connections 34 are made to 
selected wire pairs of a binder group 32 so that selected individual 
service cables 36 may be routed to user locations. 
The splice enclosure 20 seals the splice connections 34 inside of the dome 
member 22 by sealing an open end 38 of the dome member with the sealing 
means 24. The sealing means 24 comprise an upper seal neck member or 
portion 40 and a lower split shell member or portion 42. As will be 
described in greater detail hereinbelow, the dome member 22 sealably 
attaches to the upper seal neck portion 40 by means of a spline 44 and the 
upper seal neck member 40 is longitudinally engaged with the lower split 
shell member 42 by means of fastener 46. 
Viewed from the side, the splice enclosure 20 accommodates the looped 
portion 28 of the primary cable 26. As shown in greater detail in FIG. 3, 
the dome member 22, upper seal neck member 40 and lower split shell member 
42 may be cross-sectionally oval shaped or circular members in various 
sized embodiments. 
FIG. 3 provides an exploded perspective view of the splice enclosure 
providing further detail thereof. The dome member 22 is a generally 
tubular member (shown with a cross-sectionally circular shape in FIG. 3 
and a cross-sectionally oval shape in FIGS. 4-6) having an end opening 48 
formed in one end, and a closed top end 50 which is integrally formed with 
the tubular side wall portion 51 of the dome member 22. The dome member 22 
fits over the upper seal neck member 40. An enclosure sealing O-ring 52 is 
positioned in an O-ring groove 54 formed on the outside of the upper seal 
neck member 40. The O-ring 52 compressibly seals against an inside surface 
of the dome member 22 to form a seal between the upper seal neck member 40 
and the dome member 22. An annular groove 56 is formed below the O-ring 
groove 54, in both the dome 52, and the seal neck 40 cooperatively 
positioned to permit engagement by the lock spline 44 inserted thereinto 
through the aperture 122 in the dome side wall. 
The lower split shell member 42 is formed with a first half or portion 58 
and a second half or portion 60. The first portion 58 is formed with a 
hinge portion 62 which hingedly engages a hinge pin 64 formed in the 
second portion 60. The first and second portions 58, 60 form an oval or 
circular inner surface or receptacle 66 when joined. A sealing grommet 
member 68 is retained in the receptacle 66 and is longitudinally or 
axially compressed therein between the lower split shell member 42 and the 
upper seal neck member 40. Longitudinal or axial compression of the 
sealing member 68 between the lower split shell member 42 and the upper 
seal neck member 40 is accomplished by threaded fasteners 46 which engage 
seal neck flanges 70 and shell flanges 72. The longitudinal or axial 
direction of compression as used herein is to be understood as being with 
reference to the longitudinal axes of the cable portions as they pass 
through the sealing member 68. 
As shown in greater detail in FIGS. 4 and 5, the sealing member 68 is 
formed with two primary cable apertures 73, 74, two service cable 
apertures 75, 76 and one or more ground cable apertures 78. The primary 
cable and service cable apertures 73, 74, 75 and 76 are formed with radial 
slits 80, 81, 85 and 87 which extend from an edge 82 of each of the cable 
apertures 73, 74, 75 and 76 outwardly towards an outside surface or outer 
periphery 84 of the sealing member 68. The radial slits allow the cable 
apertures 73, 74, 75 and 76 to be opened to receive an entering portion 86 
and an exiting portion 88 of the looped portion 28 of the primary cable 26 
and the lengths of service cables 36. The ground cables 92 are axially 
inserted through the ground cable apertures 78 for appropriate attachment 
to the primary cable 26 and service cables 36. Alternatively, the service 
cable apertures may not have radial slits, for those new installations 
where the service cable ends are not already spliced to the primary cable 
and can therefore be inserted through an unslit hole. 
The sealing member 68, as shown in FIGS. 3-6 is a single piece unitary body 
integrally formed of a resiliently compressible material. Preferably, the 
sealing member 68 is formed of a polyether or polyester based polyurethane 
with a Shore A hardness of 3 to 40, but preferably on the order of A7 to 
A20. The sealing member 68 is composed of a material chosen to provide 
sealing of the splice enclosure 20 over a range of environmental stress 
factors including exposure to moisture, temperature, and pressure 
extremes, and certain chemicals. The material employed for this purpose 
should provide optimum hydrolytic stability, low water absorption, 
resistance to dry heat aging, have a low compression set, and also be 
resistant to airborne pollution chemicals (including, but not limited to: 
oils, water displacing lubricants, service wire and cable filling 
compounds and splice encapsulants, insecticides, herbicides and hydrogen 
sulfide and corrosion cleansing solutions) and those commonly found in 
surface soil water tables (including, but not limited to: unleaded high 
octane gasoline, sodium hydroxide, trichloroethane and sulfuric acid) as 
well as resistance to airborne and soil salts and salt water. Ideally the 
material should not vary appreciably from its initial properties when 
subjected to such stress factors in field applications. 
For example, a preferred set of criteria for sufficient sealing includes a 
minimum tensile strength of the material of at least substantially on the 
order of 70 psi; a minimum elongation of at least substantially on the 
order of 300%; minimum tear resistance of at least substantially on the 
order of 10 lbf/in; and compression set of less than substantially on the 
order of 8% after 8 days at 70.degree. F. under 25% compression. Specific 
examples of materials satisfying these criteria are designated as DEXTHANE 
200 which is a product available from Dexter/Hysol Corporation of 
Seabrook, N.H. and as BIWAX No. 82,879, a product available from BIWAX 
Corporation, Des Plaines, Ill. This choice of material for the sealing 
member 68 assures that it will maintain an acceptable seal both about its 
outer periphery 84, which abuts the internal surfaces 66 of the seal neck 
40 and split shell 42 and about the external peripheries of the entering 
and exiting cable portions 86, 88 of the primary cable 26 and the service 
cables 36 and ground cables 92 when subjected to field use conditions. 
The cross sections of the sealing member 68 shown in FIGS. 5 and 6 
illustrate in detail the interiors of the apertures 73, 74 and 75, 76. 
Each of these apertures is formed with a series of flutes 96, 97, and 98, 
99 which define an axially spaced series of similar, flexible annular 
frustoconical rings 94, 103. These rings 94, 103 are formed along an 
inside surface of each primary cable aperture 73, 74 and an inside surface 
of each service cable aperture 75, 76. The flexible annular rings 94, 103 
project upwardly and inwardly from the inside surfaces of the primary and 
service cable apertures 73, 74, 75, 76 at an angle of approximately 
45.degree., and preferably terminate in rounded inner edges. With 
reference to FIG. 7, the annular rings 94 are shown in an upwardly 
compressed state between an external periphery 101 of the primary cable 26 
and an inside surface of the primary cable aperture 74. The flexible 
annular form of the rings 94, 103 resiliently accommodate irregularities 
on the outside of the primary and service cables 26, 36 to assure a secure 
seal. These rings also accommodate primary and/or service cables over a 
range of diameters. 
With reference to FIGS. 3 and 7, the sealed reenterable splice enclosure 20 
is assembled by forming a looped portion 28 in the primary cable 26 and 
removing a portion of the cable jacket 30 therefrom to expose binder 
groups 32 contained within the primary cable 26. Entering and exiting 
portions 86, 88 of the primary cable 26 are inserted through primary cable 
apertures 73, 74 by separating the sealing member 68 at the radial slits 
80, 81 to permit passage of a segment of each cable portion 86, 88 
therethrough. Lengths of the spliced service cables 36 are inserted 
through the slits 85, 87 in the service cable apertures 75, 76. The ground 
cables 92 are inserted through the ground cable apertures 78 and 
appropriately attached to the primary cable 26. 
Thus assembled, the sealing member 68 and the primary cable 26 and service 
cable 36 are positioned between the first and second portions 58, 60 of 
the lower split shell 42. The hinge portion 62 of the first portion 58 of 
the lower split shell 42 is engaged with the hinge pin 64 of the second 
portion 60. In a clam shell fashion, the first and second portions 58, 60 
of the lower split shell 42 are closed around the outside surface 84 of 
the sealing member 68 to retain the sealing member 68 in the oval or 
circular receptacle 66 formed between the two portions 58, 60 of the lower 
split shell 42. Once fully closed, a fastener 100 is employed to attach 
apertured split shell engagement ears or brackets 102 cooperatively formed 
on opposing surfaces of the first and second portions 58, 60 of the lower 
split shell 42. The sealing member 68 is securely retained in the shell 
receptacle 66 in a generally uncompressed state. 
Next, the upper seal neck member 40 is positioned with a bottom surface 104 
thereof abutting a top surface 106 of the sealing member 68. Thus 
positioned, seal neck flange bores 108 formed through the seal neck 
flanges 70 are aligned with shell flange bores 110 formed through the 
shell flanges 72 for insertion of the threaded fasteners 46 therethrough. 
The threaded fasteners engage the threaded shell flange bores 110 to draw 
the lower split shell 42 and the upper seal neck 40 axially together 
thereby transferring axial or longitudinal compressive forces to the 
sealing member 68. 
With reference to FIG. 7, the sealing member 68 is axially or 
longitudinally compressed between the bottom surface 104 of the seal neck 
member 40 and a bottom lip 112 formed in the bottom of the receptacle of 
the lower split shell member 42. Longitudinal compression of the sealing 
member 68 resiliently compresses the sealing member material thereby 
sealing its outer periphery 84 with shell receptacle 66 and also for 
sealing the radial slits 80, 81, 85, 87, the ground cable apertures 78, 
and the service and primary cable apertures 73, 74, 75, 76. The flexible 
annular rings 94, 103 formed in the primary cable and service cable 
apertures 73, 74, 75, 76 resiliently deform to form a seal between the 
outside periphery of the cables 26, 36 and the corresponding inside 
surfaces of the apertures 73, 74, 75, 76. 
Lastly, the enclosure sealing O-ring 52 is positioned in the O-ring groove 
54 formed towards the top end of the upper seal neck member 40. The dome 
member 22 is positioned over the upper seal neck member 40 and moved 
downwardly until a bottom edge 114 of the dome member 22 abuts a seal neck 
flange 116. Thus positioned, an annular groove 56 on the seal neck member 
40 cooperatively aligns with a spline groove 118 formed on an inside 
surface 120 of the dome member 22. The flexible lock spline 44 is inserted 
through an access aperture 122 formed through the side of the dome member 
22 to engage the cooperatively positioned annular and lock spline grooves 
56, 118. The lock spline 44 acts to non-compressibly circumferentially 
engage and secure the dome member 22 with the seal neck member 40. 
With reference to FIG. 8, once the spline 44 has been fully inserted 
through the annular and spline grooves 56, 118 a slot 124 formed through a 
tab portion 126 formed on the end of the spline 44 defines a hasp-like 
structure which may be engaged with a staple or locking tab 128 formed on 
the outside of the dome member 22. Engagement of the slot 124 with the 
staple 128, and optionally the attachment of a lock or other security 
device 130 to the staple 128, prevents unintended release of the dome 
member 22 from the seal neck member 40. 
In use, the sealed reenterable splice enclosure is assembled as described 
in detail hereinabove; reentry into the splice enclosure 20 is 
accomplished by disassembling the splice enclosure 20 through the inverse 
of the steps described above. However, if complete disassembly is not 
necessary extremely quick and efficient access to the splice connections 
34 may be achieved by simply removing the dome member 22. Removal of the 
dome member requires only removing the security device 130 from the staple 
128, releasing the tab portion 126 from the staple 128 and removing the 
lock spline 44 from the annular and spline grooves 56, 118. Upon removing 
the lock spline 44 the dome member 22 can be lifted free of the seal neck 
member 40 to expose the looped portion 28 of the primary cable 26 and the 
splice connections 34 made thereto. When the necessary operations are 
completed, the dome member 22 is replaced and attached as described above. 
When accessing the splice connections 34 or cables 26, 36 as described 
herein, the seal formed by the sealing member 68 need not be disturbed and 
need never be destroyed, as is common with prior art devices. 
If a modification needs to be made to the splice enclosure 20, the 
enclosure 20 may be disassembled without destroying the sealing member 68 
or requiring that a new sealing member 68 formed as is common with the 
prior art. For example, if a new service cable 36 needs to be installed, 
the splice enclosure is disassembled and the longitudinal compressive 
forces are removed by disengaging the seal neck member from the lower 
split shell member 42. Once the compressive forces are released, the seal 
neck member 40 is removed therefrom and the new service cable may be 
inserted through the sealing member 68, aperture 76 and spliced to the 
primary cable. The seal neck 40 is then attached to the shell 42 and 
reassembled with the rest of the splice enclosure 20 as described 
hereinabove. 
It should also be clear from the drawings and the description provided 
hereinabove that the present invention may be employed to seal a tubular 
housing having two open ends. Such an open ended tube employs one sealing 
member 68 at each of the open ends to seal the contents therein. The 
sealing means 68 may be formed to provide the necessary number of 
apertures through which to project one or more members therethrough. 
Unused apertures may be sealed with a solid plug member of appropriate 
size to protect the contents of the sealed tube and/or dome-type enclosure 
from detrimental environmental effects. 
While particular embodiments of the present invention have been shown and 
described in detail herein, it may be obvious to those skilled in the art 
that changes and modifications of the present invention in its various 
aspects, may be made without departing from the invention and its broader 
aspects, some of which changes and modifications being matters of routine 
engineering or design and others being apparent after study. As such, the 
scope of the invention should not be limited by the particular embodiments 
and specific constructions described herein, but should be defined by the 
appended claims and equivalents thereof. Accordingly, the aim of the 
appended claims is to cover all such changes and modifications as fall 
within the true spirit and scope of the invention.