CA1113383A - Cable pedestal guard system and method - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A pedestal enclosure for above ground extensions of underground cables in combination with a rigid, foamed, cell-developed, insulating, polymeric, thermosetting, plastic material in which a substantial number of the cells contain encapsulated therein a gaseous state effective rodent retardant.

Description

;33~3 B~CKGROUND OF THE INVENTION
This invention relates to outdoor, above ground electrical closures known as pedestals, and more particularly to a pedestal which is designed t~
prevent the bothersome problem of insect and rodent access to the interior chamber defined by the pedestal.
It is well known that it is necessary that underground cables have above ground extensions in or-der to provide access to the underground cable for repair, maintenance and the like. Requirements for a ~;
satisfactory pedestal are that it be serviceable from an electrical maintenance standpoint so that splices and connections to the cable may be made efficiently and reliably; the pedestal must be of a mechanical design such that access to the interior chamber defined by the pedestal is facilitated; the pedestal must be of a construction such that it will withstand possible rough treatment in its installation; and, of course, the pedestal must provide for easy installation and ~
convenient cable access. ~`
Because the cables which are fed into the in-terior chamber of the pedestal stand are o-E varying sizes, most pedestals now sold do not have a pedestal bottom cover. The reason for this is simply that there is no standard access opening size for the cables to be fed into the interior pedestal chamber. Thus, for example, ~
if the access opening were quite large and the cable -small, the opening would be very large allowing easy access by insects, rodents and the like. On the other hand, if the cable is very large and the access opening 3~3 : ~ ~

small, the bottom of the pedestal stand would have to be reamed out in order to increase the o~ening size to permit access. It is for this reason that pedestal ::
stands do not have a bottom cover and the pedetal cham-ber is simply extended down into the ground, with the ground providing the bottom. ~`
One particularly bothersome problem with pdestal stands is that the interior chamber o~ the .:~
pedestal stand provides a warmer desirable place for insects and rodents. Thus, rats, mice and other small burrowing rodents often will chew the insulating material away from the cable wires and dig a hole around the wires and burrow up into the pedestal chamber where ~ `
they nest. This, of course, presents an undesirable environment for maintenance people who open .t~e pedestal stands. .
Accordingly, it is an object of this invention to provide a pedestal stand which retards insect and :
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: rodent access thereto.
. Another object of this invention is to provide : such a pedestal stand, and a system therefor, which can ~;
be used with pedestals presently sold on the marketplace without modification.
Another object of this invention is to provide a method of retardin~ rodent and insect access to the -interior chamber of a pedestal stand. .
A still further object of this invention is ~; to provide a rigidr foamed, cell-developed, polymeric, material for use at the bottom of a pedestal stand cham-ber, with the cells containing in a gaseous state an insect and rodent retardant ~hich i5 releasable upon ~:`,

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3~33 rupture of the cells.
A still further object of the invention is to provide a method of encapsulating a normally liquid rodent retardant in the rigid cells of a foamed thermo- ~ :
settingr insulative material. : ;

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l ~ 33~3 Yet another object oE this invention is to provide a kit of all liquid .ingredients for forming a rigid, .
foamed, cell-developed, polymeric, plastic, material co~taining encapsulated gaseous rodent retardant in the cells of ~he plastic material, the kit being small and usable directly at the pedestal site by pouring reaction in~redients together and pouring the rni.xed-reaction :
ingred.ients into the bottom of a pedestal chamber.
The me-thod and means of accomplishing.these and other objects will become apparent from the detailed ~ ;
description of the lnvention which follows below.

BRIEF l)ESCRIPTION OF THE DRAWII~GS ~;~
Fic3ure 1 is a perspective view, with parts broken . ~ .
away, of a pedestal stand containing the foamed, ` insulative, thennosettin~, material in.the bottom of :
. the pedestal cavity. . !:~
;: Figure 2 is an elevated side view of tlle pedestal of Figure 1. .
Figure 3 is a plan view of the pedestal with the top cover removed loo~ing down into the pedestal cavity.
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SUMMARY OF TlIE INVENTION
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The invention relates to the combination of a pedestal and at the bottom of.the pedestal, in a chamber, a foamed, cell~developed, rigid, thermosettiny~ insulative, : plastic material, a substantial number of-the cells containing a ~aseous rodent retardant which is released :`
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`~ 33~3 upon cell rupture. The invention also relates to a method o~ retarding rodent access to the interior cable ¦ holding chamber of a pedestal, to a method of encapsulating in a gaseous state~a normally liquid rodent retardant in a rigid~ cell-developed, thermosetting material, to the composition of the rigid, foamed, cell-developed, polymeric, material having encapsulated therein gaseous rodent ~etardant, and to a kit for use at a pedestal site for forming the desired foamed, thermosettin~, plastic material in the bottom of a pedestal chamber. ~` ;
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DETAI LED DESCRIPTION OF THE INVENTION ::~`
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Referring now to Figure 1, there is illustrated a pedestal 10 of conventional construction supported in ;-the ground 12 with the earth line d picted at arrow 14, ;
for housing an above ground extension 16 of underground cable 18.
~ The pedestal 10 includes~a pedestal mounting stand ; ~ 20 which is imbedded into the earth 12 to provide a perpendicular mounting stake.
Mounted to the sides of pedestal stand 20 are cover mounting screws 22 and 24. As depicted, it can be seen that one pedestal mounting screw 22 is above the earth line and the other 24 below the earth line. Correspond-ing mounting screws appear on the opposite side of pedestal stand 20 and are not depicted herein. ;~
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Pedestal housing 26, as depicted, i:5 oE U-shaped construction having a front surface 28, and opposing sides 30 and 32. Sides 30 and 32 have L~shaped slots 34 and 36 for sliding receipt of mounting screws 22 and 24 in order to support housing 26 on pedestal stand 20. Thus, as can be seen, pedestal stand 20 forms the back closure of pedestal housing 26. ..
As mentioned previously/ pedestal housing 26 does not have a bottom and cable 18 extends from its under-ground position upwardly through the bottom opening of pedestal housing 20 into the interiorally defined ~:
chamber 38. Top cover 40 is slidably received on the top portion of houslng 26 to provide a top closure for the pedestal housi.ny 26. ;.
In the normal means of operation, pedestal lO is mounted as described and ground 12 below the earth line 14 provides the bottom closure for pedestal housiny 26. I :~ .
~lowever, thls is unsatisfactory in that small rodents, insects or the like chew the above ground extension 16 of cable 18, burrow up through the yround and find a convenient and desirable nesting place inside of pedestal housing 26 in chamber 38. ~ :
In accordance with this invention, this undesired entry into chamber 38 by rodents and insects is pre-vented by filllng the bottom portion of chamber 38 with a rigid foamed material which contains encapsulated within the cells of the foam, a gaseous repellant, or _5_ l ;, ' l ,. : : : ' !
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. ' ~ g i3383 ~' retar~ant, the two tennx being used inte~cllangeably herein, which upon cell ~upture, releases rodent retardant into the enviromnent thereby driving away would-be intru~ers. ~`
As can be seen, a substantial portion, and especlally all of the lower portion of chamber 38 is cornpletely filled with foamed, polymeric material 42.
The material 42 is an insulative polyrneric, thermo-setting, plastic, ma-terial which is rigid and has a ; lo definite cellular structure 44. Encapsulated in cells 44 in a gaseous state is an insect and rodent retardant The insulative rigid foamed polymeric material 42 is prepared in situ within the chamber 38 of the pedes-tal at the actual in use site of the pedestal. The pedestal is set ùp in the conventional fashion previously described herein and the top cover 40 left open.
~; All thermosetting plastic polymeric materials such as 42 are a polymer of at least two liquid ingredients, ~i for simplicity referred to herein as component A and component B. Liquid components A and B are mixed ;
together in a s1ngle container the contents shaken vigorously for several seconds, at which point the ;
polymerizing reaction begins; the reaction becomes exo-- thermic and starts to "cream". At this point the material is poured into ~he pedestal cavity, which ~; -preferably has a covering sheet 46 positioned on top of the ground at the bottom of the chamber 38. One of the polymer forming ingredients, let's say for example, . - ,~
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'I SL'L133~33 compone nt ~, con t ains a normally 1iqwLd rodent re ta rdant which is capable of volatilization to a yaseous state upon the exotherrnic thermoset-ting reactlon of the liquid inyredients A and B when combined. The heat of reaction in the formation of the Eoam causes the rodent retardant to volatilize and as the foam becomes tacky and ultimately ; rigid, the rodent retardant is encapsulated into the ;;
cells 44 of the foamed polymeric material 42. Thereafter, rodents that eat away the insulation of cable 18 and o burrow into the interior chamber 38 of pedestal housiny 26 are, upon biting into the foam ma~erial 42, rèpulsed ~-; by the rodent retardant whicll is released upon rup-ture o~ cells A4~ As a result, the rodents and insects find interior chamher 38 a non-desirable nesting place.
It should be noted that it is essential that foamed polymeric material 42 cont~in within cells 44 a gaseous state rodent retardant. In the absence of such a retardant, it has been found that the foamed polymeric ma~terial 42 does not inhibit rodents but in fact Inay attract them. Thus, - 20 the rodents burrow through the ~round into the foam material 42, and while they are not attracted by the rigid foamed material 42, they simply chew it away to provide a ;~;
snuy insulated and warm interior cavity for nesting.
Thus, a foam alone without its combination with gaseous cell encapsulated rodent retardantr will not prove effective for u in applic~nt's inventlon.

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As heretofore mentioned, foamed, insulative, po:Lymeric, thermosetting plastics which are ri~id and ilave an interior cell structure are in all cases formed by mixing at least two norma].ly liquid organic chemical ingredients~ Typically, one of the ingredients provides the basic polymer units, and ~:
the other, often a cross linJcing agent toyether with a :~ ~
polymer.ization catalyst and a foaming agellt such as a :: :
conventiollal blowing agent which generates gaseous material to cause foaming. . ~:
10 ¦ Rigid type plastic foams, such as polyurethane ~oams 1~
and polystyrene foams are known and are useful herein. ~ -Typical blowing agents which are incorporated into the organic liquid in~redients includ~ halocarbons such as :
monoflurotrichloromethane. Other materials which can be used to provide rigid foams include polyvinyl chloride foams, often called expanded PVC. .
As heretofore mentioned, the precise foaming material :
42 used is not critical. E~owever, it must be the result of mixing at le~ast two liquid chemical ingredients, i-t must form a riyid/ foam material, having a cell-developed structure, it must be thermosetting, it must be exothermic in the reaction forming the foam material 42, and it must be insulative. The ~. ~.
reaction ingredlents must be exothermic in order that they provide the necessary heating reaction to volatilize the rodent : ~.
retardant from its normally liquid state to a gaseous state so that it will be encapsulated within the cells 44 of the foam poly rlc material 42.

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33~3 reeerred foams mee~ing all of ~tl~ese requirements are ¦ polyuretllane foams, which are made thermosetting by the ¦ condensation reaction of a polyisQcyanate and a hydroxyl ¦ containing material such as: a polyol. Typically in thei~ 1 formation, a polyether such as polypropylene glycol ~s treated with a di-isocyanate in the presence of some water, and a ~:
¦ cata.lyst (amines, tln so~ps, organic tin compounds or the : ~:
I li.l~e ~ . As the polymer orms r the water reacts with the .~ I isocyanate groups to ca~lse cross-linking and also produces .~ 10 carbon dioxide which causes foaminy. In o-ther cases, trifluoro- :~
methalle or similar volatile materials a.re incorporated in . .
. ~ small amounts as a blo~ing agent.
- In the most preferred polyurethane system, the flrst liquid ingredient, component A, is a polymethylene, .~ polyphenyl isocyanate (about 98% to 9g% with from about .~ 1% to about 2% o~ the. propoxylated glycerine present as a copolymer). This liquid is the isocyanate cornponent. : : .
The other liquid component, B, is propoxylated, aromatic -.
amino polyols, 53% to 54% and 15% to 16~ of 0,0-diethyl-N-N-bis [2 hydroxy ethyll-amino phenyl-phosphonates, from :~
about 7% to about 8% propoxylated glycerine, from about 0. 7%
to about 0. 8% of a silicone oil, and from about .
22% to about 2396 of trichlorofluoromethane blowing agent.
Component A is sold by Upjohn under the designation "Isocyanate Systems CPR 402" and the registered trademar]c :~
is PAPID Component 13 is sold by the same suppIier, Upjohn, ~ :
using the trade name designation "CPR 402, ~igid Urethane F oam " . ~
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Il ~113383 l ~., ~n adcli-tive to the flrst component is a norrnally liquld ~i rodent retarclant which upon the heat of reaction of formation ¦ of the polyurethane foam will volatilize to provide gaseous r.
retardant encapsulated within the cells 44 of the rigid foam 42. The most preferred rodent retardant is 0,0-dimethyl 0-2, 4,5-trichlorophenyl phosphorothioatel which is added to the isocyanate component, component A. The amount added to the isocyanate component will vary, but typically about a quart and a hali estimated to be abou-t 2 pounds, can be added to a 55 gallon, 500 pound drum of component A. Of B~
course, this is just a convenient level and other levels can be added~ The amount of Component A to be mixed witl Component B is also variable, but a 1:1 ratio has been found satisfactory. ' 0,0 dimethyl 0-2,4,5-trichlorophenyl phosphorothioate is ;
the preferred rodent retardant since it is soluble in the isocyanate component A, and will vaporize into a gaseous state at the normal heat o reaction when component ~ and component B are mixed together.
It has been found convenient for use in this invention to have the isocyanate componentr Component A, in an inert container, and to have the basic polyol material, component B, F; ::
in a second inert container. Of course, as previously mentioned, the retardant is dissolved in the isocyanate component.
Both of these containers are then sealed into a flexible shipping bag container such as a polyethylene or polypropylene plastic container. The Xit is then sold to the consumer user.

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ll 33~3 At the pedestal s.ite, the kit is opened, one bott.le of ~ :
active in~redient .is poured into the second bottle of active ingredient, after which ~he remaining filled bottle is capped, shaken vi~orously for from 5 to ~0` seconds, and then as the R
products start to crea~ and as the reaction becomes exothermic as evidenced by warming i.n the holder's hancl, the mixed r liquid ingredients are poure~ into the bottom of the pedestal ~ cavity 38~ The foam ~.ill rise in approximately 2-1/2 rninutes : and be tack free after about 2 to 3 addit.ional minutes, with ~ :
total rigidity occurring in about one hour. ~he retardant i9 ~.
vaporized by the heat of reac~ion and encapsulated in the cells ~4 of the rigid foam 42.
In one preferred emhodiment, the kit is used by E;.rst : tearing open the plastic bag and placing the plastic bag at the bottom of the pedestal chamber 38, adjacent to the ground and surrounding as well extension cable 16. This ~ ~;
prevents seepage of the liquid f~aming ingredients into the !;~
ground before formation of the foam occurs. i~
Thus, as can be seen, applicant's invention allows . 20 the continued use of conventional pedestals, but yet will provide a convenient and economically satisfactory means of rodent repellant. It therefore accomplishes at least all of ~;
the stated objects of the invention~
EXAMP~E
A kit containing two inert bottles of polymer forming components A and B is prepared. Component bottle A contains 1.5 ounces of polymethalene, polyphenyl isocyanate (about 98%
to about 98.9% by weight) and from abou~ 1% to about 2% of . ~ . .
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propoxylated glycerine present as a co-polymer. This liquid isocyanate component is sok3 by Upjohn Company under the trademark CPR 402. It contains mixed therewith between 3%
~,!; and 4~ hy wei~3ht of 0,0-dime~hyl 0-2,~,5-trichlorophenyl phosphorothioate which is a li(~uid animal retardant and insect retardant.
The second component bottle in the kit, component ~, contains propoxylated aromatic amino polyols (S3~ to 54~, 15% to 16% of 0,0-diethyl-N-n-bis~~2 hydroxy ethyl] amino phenylphospllonates, froTn about 7% to about 8% propoxylatecl glycerine, from about 0.7~ to about 0.8~ of a silicone oil, and froln about 22~ to about 23~ of trichlorofluromethane blowing a~ent. This component B is also sold by the same supplier Upjohn, usin(3 a tradename desi(~nation CPR 402, ri~id urethane foam. Both component bot-tles are contained in a polyethylene tearable, flexible package.
The bag is cut open, spread around the base of the cables 1~ in a pedestal 10, the contents of component bottle ~ ;
A are poured~into component bottle B, and component bottle B
is then capped and shaken vi~orously for from S to lO seconds.
It is noted that in about 28 seconds the mixture beyins to cream and the bottle feels warm ~o the touch. ~t this point the mixture is poured into the bottom of charnber 38 of pedestal 10. The foam rises in about 2 minutes and 35 seconds; becomes tacky after about another two minutes, and total rigidity is reached within one hour. The temperature obta ed by the exoth~rmic reactro- w~s about 120F.

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AEter the :Eoaminy occurred, -the product ~/as examined ancl ~ ~
it was found that gaseous rodent retardant was encapsulated ~ ~:
within the formed cells of the foam 42. Moreover`, it was noted that the foam adhered to the pedestal and the cable alike with no damage to either. The poduct itsel~ was also found to be insulative. : r Numerous tests with actual in-use pedestals employing .
the invention as described herein, showed that rodents were repulsed and that they failed to nest in pedestals employiny :
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Claims (11)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In combination, a pedestal enclosure for enclosing above ground extensions of underground cables, which defines a cable holding chamber having an open bottom adapted for extension into the ground for access to underground cables, and, a rigid, foamed, cell developed, insulating, polymeric, thermosetting, plastic material, in which a substantial number of said cells contain encapsulated therein an effective gaseous rodent retardant in said holding chamber and blocking the bottom thereof.

2. The combination of claim 1 wherein said rigid, foamed, cell-developed, polymeric, thermosetting, plastic material is a polyurethane foam system.

3. A method of retarding rodent access to the interior cable holding chamber of a cable pedestal, having an open bottom, said method comprising: installing a cable pedestal having an open bottom; mixing at least two normally liquid organic chemical ingredients capable upon exothermic reaction of providing a rigid thermosetting foamed, cell-developed polymer, at least one of said ingredients containing therein a normally liquid rodent retardant capable of volatilization to a gaseous state upon the exothermic, thermosetting reaction of said other ingredients, and pouring said mixed ingredients into said holding chamber of said pedestal at a location so as to block access to the interior thereof through said open bottom.

4. The method of claim 3 wherein an addi-tional step includes placing a covering layer of flexi-ble sheet material at the bottom of said chamber before said mixed ingredients are poured into said chamber.

5. The method of claim 3 wherein said mixed ingredients are not poured into said pedestal chamber until the mixture begins to cream and the reaction becomes exothermic.

6. A method of claim 11 wherein normally liquid rodent retardant is soluble in one of the reac-tion starting materials.

7. A rigid, foamed, cell-developed, thermally set, polymeric material, and encapsulated in a substan-tial number of the cells thereof, a gaseous state rodent retardant for release to the environment upon rupture of said cells.

8. The composition of claim 7 wherein said foamed polymeric material is a polyurethane foam.

9. The composition of claim 8 wherein said rodent retardant is 0,0-dimethyl 0-2,4,5-trichlorophenyl phosphorothioate.

10. A kit for forming a rigid, foamed, cell-developed, polymeric, plastic material in which a sub-stantial number of cells encapsulate an effective volatilized rodent retardant for release upon rapture of said cells, comprising: a first container with liquid isocyanate, a second container with a polyether, at least one of said containers having a blowing agent therein, and at least one of said containers having a normally liquid rodent retardant therein which is capable of volatilization upon mixing of the ingredients of said containers, and a flexible shipping bag containing said first and second containers.

11. A method of encapsulating, in a gaseous state, a normally liquid rodent retardant in the cell structure of a rigid, foamed, cell-developed, thermo-setting, material formed by mixing two normally liquid chemical ingredients which react exothermally to provide a thermoset material, comprising, adding to one of said chemical ingredients used in the preparation of said foamed material a normally liquid rodent retardant which is miscible therewith, and which is capable of volatilization at the exothermic reaction temperature achieved by mixing said two normally liquid ingredients;
adding said one ingredient containing said rodent retar-dant to the other of said ingredients; whereby said exothermic reaction forming said rigid, foamed, cell-developed, thermosetting material, and said retardant volatilizes and is trapped in said cells of material for release upon subsequent cell rupture.