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Description  |
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BACKGROUND OF THE INVENTION
This invention relates to utility cover extensions and more particularly to
utility cover extensions for adjusting the level of a utility cover to a
new grade.
In the repair and resurfacing of streets and highways, it is frequently
found that the repaired or resurfaced roadway is substantially higher than
the original roadway. Accordingly, the top surface of the utility covers
in the roadway, such as manhole covers, water and gas valve covers, gas
and water meter covers and the like, are disposed substantially below the
new road surface. This lower position of the utility cover creates a
hazardous driving condition. These utility covers must be raised in order
to adjust their top surfaces to that of the new level of the roadway.
In the original roadway, the utility cover is positioned over an access
opening of a utility housing. The access opening generally has a support
flange on which the utility cover is supported with the top surface of the
utility cover to the level as the original highway.
One known construction for raising a utility cover to the new grade of the
repaired or resurfaced roadway are manhole cover supports used to raise a
manhole cover above the manhole housing so that the top of the manhole
cover is at the new grade of the roadway. These manhole cover supports are
designed to fit into the manhole housing and support the cover so that its
top surface is at the new level of the roadway. The use of such manhole
cover supports are desirable since it becomes unnecessary to replace the
frame which is embedded in a paved road.
When raising the utility cover to a new grade, it is desirable to provide a
utility cover support which when assembled with the utility frame and
cover resists displacement or dislocation of those components under normal
service conditions of the roadway. Under such service conditions various
vehicle traffic loadings occur including axle, wheel and impact loadings,
and various temperature conditions, such as steam from steam lines, and
various chemical conditions, for example, spills of oil or gasoline on the
roadway, also occur. If such service conditions create displacement or
dislocation of the utility cover extension, utility housing, or cover, a
depression or protrusion in the road surface will be realized which
creates a driving hazard.
Furthermore, other hazardous driving conditions may be created, for
example, when a impact loading is made on one of the components, such as
the cover, and the cover pops out of the opening. Accordingly, it is
desirable that relative movement between the components be resisted under
such service conditions which includes the ability to absorb impact
loadings, operate under various temperature conditions and various
chemical environments.
It is also desirable to provide a utility cover support which resists
rotation of the utility cover which results in wear between the
components. For example, after repeatedly impacting the utility cover on
one side, the cover tends to rotate thus abrading the surfaces between the
cover and the utility support. Such wear creates a looser fit and allows
more movement between the cover and the cover support. As the surfaces
between the utility cover and utility cover support wear, the likelihood
of displacement or dislocation of the cover under normal service
conditions is increased which accordingly creates a hazardous driving
condition.
It is also desirable to minimize the flow of surface water and other
contaminants into the access opening of the utility housing. Water
infiltration into the access opening of the utility housing has been a
continuous problem with telephone companies, municipal public work
departments and other public utility companies. For example, it is
desirable to segregate different types of municipal water systems. Large
volumes of additional waste water must be treated when surface water
infiltrates into a sewer system through a manhole. The overloading of
sewage systems has increased in importance from many years ago and the key
factor is that today there is significantly less pervious area than there
was years ago. This factor is due to larger impervious street surfaces
that collect more drainage water as well as smaller building lot sizes
which cut down on the amount of overall pervious area. By significantly
decreasing the flow of storm and drainage water into the access opening,
existing water treatment facilities can handle more sewage capacity.
In the case of electric and gas underground systems, in many instances,
continuous pumping of water is required before utility men can enter a
manhole because of water infiltration between the manhole cover
components. In the case of utility cover assemblies for utility valves,
meters and the like, the surface water and other contaminants such as
dirt, deteriorate the valve or meter and inhibit its operation and ease of
access thereto. It is also desirable to keep contaminants out of the
utility frame in the case of gas and water meters to allow for ready
access to the gas and water meters and reading thereof and their
operation.
It is desirable to provide a utility cover support which reduces noise
generated under normal service conditions. It is also desirable to absorb
and dissipate the energy exerted on the components of the utility cover
support assembly under normal service conditions.
SUMMARY OF THE INVENTION
The present invention provides the above described desireable features with
an improved utility cover extension. The utility cover extension of the
present invention is provided to be inserted into the access opening of a
utility housing for vertically adjusting the level of a utility cover over
the access opening to a new grade. The access opening of the utility
housing includes a support flange with an upwardly and outwardly sloping
peripheral surface extending from the flange. The utility cover has a
bottom and an outer peripheral surface extending therefrom. The extension
has an assembled and an unassembled condition with the utility cover and
housing.
The extension has a bottom portion for insertion into the access opening of
the utility housing and an upper portion for receiving the utility cover
therein The bottom portion has a bottom support surface positionable
adjacent the support flange of the utility housing and a bottom outer
peripheral surface extending upwardly from the bottom support surface and
upwardly sloping peripheral surface of the utility housing when in an
assembled condition.
The upper portion has an upper support surface for supporting the utility
cover and an upper inner peripheral surface extending upwardly from the
upper support surface and positionable adjacent to and complimentary with
the outer peripheral surface of the cover when in the assembled condition.
The utility extension includes an extension frame and a compressible
material forming at least a portion of the peripheral surfaces of the
extension housing. The peripheral surfaces of the extension have a
circumference with an interference fit with its complimentary peripheral
surface of the utility housing and cover. In an assembled condition, the
compressible material is compressed and frictionally engages under
compression the utility cover and the utility housing and provides a
sealing relationship therebetween.
The present invention provides methods for improving the frictional
engagement of a utility cover extension to a utility housing or a utility
cover. The present invention also provides methods for improving the seal
between the utility cover extension and a utility housing or cover.
The present invention achieves the desired feature of resisting the
premature displacement or dislocation of the utility cover extension
assembly by increasing the frictional forces between the components of a
utility cover extension assembly. By forming the peripheral surfaces of
the utility cover extension from a flexible compressible material, the
forces exerted on the assembly are absorbed and dissipated and the
components of the assembly urged to return to their original position.
In an unassembled condition, and when the cover extension is at its
assembled circumferential condition, the complimentary peripheral surfaces
of the utility housing, extension and cover have an interference fit. The
circumference of the outer peripheral surface of the lower portion of the
extension is greater than the circumference of the inner peripheral
surface of the utility housing. The upper inner peripheral surface of the
upper portion of the utility cover extension is less than the
circumference of the utility cover. When the utility cover extension is
assembled with the housing, the compressible material is compressed and
deforms to the above mentioned circumference of the inner peripheral
surface of the frame. When the cover is assembled with the utility cover
extension the inner peripheral surface of the upper portion of the
extension is deformed and the compressible material compressed to the
configuration of the circumference of outer peripheral surface of the
cover. In such an assembled relationship the cover assembly provides for
the resilient frictional interconnection of the components of the utility
cover extension assembly while allowing for resilient movement of the
components therebetween to absorb and dissipate impact forces experienced
in normal service conditions without losing frictional engagement of the
components.
The present invention also provides the desirable feature of resisting
infiltration of surface water and other contaminants into the access
opening. The compressible material provides for sealing the complimentary
peripheral surfaces between the cover and cover extension and also between
the cover extension and the frame. This seal is maintained even with
slight relative movement of parts of the cover extension assembly since
the compressible material flexes and maintains a seal during such
movement. In the case of an adjustable cover support, the compressible
material is sufficiently flexible to fill the spaces between the segments
of the rigid portion of the cover support and maintain continuous contact
about the entire periphery of the complimentary peripheral surfaces.
Utility cover extensions of the present invention may have a wide variety
of constructions and designs. For example, manhole cover supports may be
of solid continuous construction, as cast rings, or adjustable to fit
various manhole housing openings. The geometric configurations of utility
cover supports may be of a variety of configurations for example, round,
square, rectangular or triangular shapes dependent on the shape of the
utility housing and frame and may be manufactured by forming, fabricating
or casting.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of a cover extension of this
invention assembled for use in the top of a utility housing;
FIG. 2 is a cross-sectional view of the utility cover extension shown in
FIG. 1 and taken along line 2--2 of FIG. 1 when the cover is in an
unassembled condition;
FIG. 3 is a fragmentary sectional view of the cover extension and housing
shown in FIG. 1 and taken along line 2--2 of FIG. 1;
FIG. 4 is sectional view of the cover extension and housing taken line 2--2
of FIG. 1 with a cover assembled therewith;
FIG. 5 is an exploded perspective view of another embodiment of a cover
extension of the present invention mounted in a utility cover housing;
FIG. 6 is a sectional view of the cover extension shown in FIG. 5 and taken
along line 6--6 thereof in an unmounted condition;
FIG. 7 is a cross-sectional view of the cover extension and housing shown
in FIG. 5 in assembled condition taken along line 6--6 thereof;
FIG. 8 is a sectional view of the extension and housing shown in FIG. 7
with a cover assembled therewith;
FIG. 9 is a sectional view of yet another embodiment of the cover extension
of the present invention when in an unassembled condition;
FIG. 10 is a cross-sectional view cover extension shown in FIG. 9 when
assembled with a housing;
FIG. 11 is a cross-sectional view of the cover extension shown in FIG. 10
when assembled with a cover;
FIG 12 is a sectional view of a further embodiment of the cover extension
of the present invention when in an unassembled condition;
FIG. 13 is a cross-sectional view of the cover extension shown in FIG. 12
when assembled with a utility housing and cover;
FIG. 14 is a cross-sectional view of the cover extension shown in FIG. 13
taken through the adjustable portion of the cover extension;
DETAILED DESCRIPTION OF THE INVENTION
Referring now more specifically to the drawings, a utility cover extension
10 embodying the features of the present invention is shown in FIGS. 1-4.
The utility cover extension 10 is provided for insertion into a utility
housing 12 having an access opening 14 therethrough. The utility cover
extension 10 is provided for vertically adjusting to a new grade the level
of the utility cover 16 over the access opening 14 of the housing 12. The
access opening 14 includes a support flange 18 with an upwardly sloping
peripheral surface 20 extending therefrom. The utility cover 16 has a
bottom 22 and an outer peripheral surface 24 extending therefrom.
The extension 10 has an unassembled condition shown in FIG. 2 and an
assembled condition shown in FIG. 4. In the assembled condition, the
extension 10, housing 12, and cover 16 form the utility cover extension
assembly 17 as shown in FIG. 4.
The utility cover extension 10 has a bottom portion 26 and an upper portion
28. The bottom portion 26 has a bottom support surface 30 positionable
adjacent the support flange 18 of the utility housing 12 and a bottom
outer peripheral surface 32 extending upwardly from the bottom support
surface 30. In the assembled condition, the outer peripheral surface 32 of
the extension 10 is positioned adjacent to and is complimentary with the
peripheral surface 20 of the housing 12. The support flange 18 includes a
bottom surface 19 on which the bottom support surface 30 of the extension
10 rests.
The upper portion 28 of the extension 10 is provided for receiving the
utility cover 16 therein. The upper portion 28 includes an upper support
surface 34 which, when in the assembled condition, is adjacent to the
bottom 22 of the cover 16 and supports the cover thereon. The upper
portion 28 has an upper inner peripheral surface 36 extending upwardly
from the support surface 34. The peripheral surface 36 is positionable
adjacent to and complimentary with the outer peripheral surface 24 of the
cover 16 when in the assembled condition. For ease of description, the
inner peripheral surface 20 of the housing 12 and adjacent outer
peripheral surface 32 of the bottom portion 26 of the cover extension 10
will be referred to as complimentary peripheral surfaces and the outer
peripheral surface 24 of the cover 16 and adjacent inner peripheral
surface 36 of the upper portion 28 of the cover extension 10 will be
referred to as complimentary peripheral surfaces.
The extension 10 includes an extension frame 38 and a compressible material
40 forming the bottom and upper support surfaces 30, 34 respectively and
the bottom and upper peripheral surfaces 32, 36 respectively. When in the
unassembled condition, the circumference 42 of the bottom outer peripheral
surface 32 of the extension 10 is greater than the circumference 44 of the
peripheral surface 20 of the housing 12. Also, when in the unassembled
condition, the circumference 46 of the upper peripheral surface 36 of the
extension 10 is greater than the circumference 48 of the outer peripheral
surface 24 of the cover 16. Accordingly, an interference fit between the
complimentary peripheral surfaces 20, 32 and the complimentary peripheral
surfaces 24, 36 exists in the unassembled condition.
When in the assembled condition, the compressible material 40 is compressed
so that the circumference of the peripheral surfaces 32, 36 of the
extension 10 conform to and are substantially equal to the circumferences
44, 48 of the peripheral surfaces 20, 24 respectively. The compressible
material 40 in the assembled condition provides for frictional engagement
between the complimentary parts 10 and 12 and the complimentary parts 10
and 16 of the utility cover extension assembly 17 The support surfaces 30,
34 are also compressed in an assembled condition.
The outer peripheral surface 24 of the cover defines an obtuse angle of
from between 91 degrees to 110 degrees with the plane of the bottom
surface 22 of the cover 16. Likewise, the outwardly sloping peripheral
surface 20 of the housing 12 forms an obtuse angle of from between 91
degrees and 110 degrees with the plane of the bottom surface 19 from which
the peripheral surface 20 extends. By providing the obtuse angles between
the peripheral surface 12 and bottom 22 of the cover 16 and the peripheral
surface 20 and bottom surface 19 of the housing 12, the extension 10 may
be more readily assembled with the housing and cover 12, 16 respectively.
This angular relationship provides for advantageous assembly of the
extension 10, housing 12, and cover 16 by providing a camming action to
compress the material 40 as the components 10, 12 and 16 are assembled as
will be hereinafter described. It should be understood that the term
circumference as used in connection with angular peripheral surfaces is
the circumference at any particular point along the angular surface.
The compressible material 40 extends continuously about the entire
circumferences 42, 46 of the peripheral surfaces 32, 36 of the extension
10 and continuously about the bottom and upper support surfaces 30, 34 of
the extension 10. When the compressible material is compressed, a seal is
created between the complimentary parts 10, 12, and the complimentary
parts 10, 16 of the utility cover extension assembly 17 to resist the flow
of surface water and other contaminants through the complimentary surfaces
24, 36, and 22, 34 and 20, 32 and 19, 30.
In the embodiment of the utility cover extension 10 shown in FIGS. 1-4, the
utility cover extension 10 includes an extension frame 38 and a
compressible material 40 secured to the frame. The compressible material
may be selected from a wide variety of both natural and synthetic
materials having the properties of compressibility, flexibility, density,
elongation, toughness, and impermeability necessary to meet the service
conditions described above. The desired characteristics of such a
compressible material when used as described by the present invention
increases and maintains the frictional forces maintaining the components
of the utility cover extension assembly 17 in an assembled relationship,
absorbs impact loadings, resists the flow of surface liquids and
contaminants through the complimentary surfaces of the utility cover
extension assembly 17, decreases the noise level of the extension assembly
under operating service conditions, is able to operate under various
temperature conditions and in various chemical environments and extends
the effective service life of the utility cover extension assembly 17. A
wide variety of materials of both natural and synthetic origins and
combinations thereof meet these requisites. For example, rubber and
plastic materials may be used along with combinations of materials such as
cork fillers bonded together with resinous, protein or synthetic binders.
In order to achieve the sealing properties of the present invention the
material 40 has the characteristic of impermeability to water. This
characteristic can be obtained by using a closed cell elastomer or
flexible plastic of the appropriate density and compressibility. Preferred
materials for use as the compressible material 40 are cast microcellular
urethane elastomers, polyurethane foams, rubber, and plastics if properly
formulated and processed. Some examples are: polyisoprene, both natural
and synthetic, styrene butadiene, polybutadiene, butyl rubber, chlorobutyl
rubber, neoprene, ethylene propylene rubber, nitrile, polyacrylate rubber,
polysulfide, silicone elastomers, flouroelastomers, polyethylene acrylate,
polyvinyl acetate, epichlorohydrin, chlorosulfonated plyethylene,
crosslinked polyethylene, polyethylene, polypropylene, plasticized
polyvinyl chloride, polyvinilidene chloride, ionomer, thermoplastic
polyester, and polyurethane gum rubber.
One preferred material is Uniroyal, Inc.'s "ADIPRENE" #L167, a polyurethane
foam rubber further described by a formula recipe:
100 parts--L-167
0.3 parts--Water
0.3 parts--"DABCO-33LV"
1.4 parts--"DC-193"
16.0 parts--"BC"
These additives are furnished as follows:
DABCO-33LV: Air Products Inc., Allentown, Pa.
DC-193: Dow-Corning Inc., Midland, Mich.
BC: Palmer, Davis, Sieka Inc., Port Washington, N.Y.
The extension frame 38 of the present invention includes a base 56 having a
top and a bottom surface 52, 54 respectively, with a lateral support
portion 56 extending upwardly from the top surface 52 and terminating in a
flange 62. The lateral support portion 56 has an inside surface 58 and the
lateral support portion 56 and the outer portion of the base 50 has an
outside surface 60.
In the embodiment described in FIGS. 1-4, the material 40 extends around
the surfaces 52, 54, 58, 60 and the flange 62 and is bonded thereto. The
frame 38 provides structural rigidity to the extension 10 and the strength
to operate in the service conditions described above.
Means are provided to bond the compressible material 40 to the surfaces 52,
54, 58, 60 and flange 62. For example, a permanent adhesion of the cured
"ADIPRENE" polyurethane foam rubber is accomplished by a chemical and
mechanical bonding process by using the bonding agent 63 "CHEMLOK" #218 as
manufactured by the Lord Corporation, Erie, Pa. The metal surfaces 52, 54,
58, 60, 62 of the extension frame 38 are thoroughly cleaned. The bonding
agent 63 is then applied to the surfaces 52, 54, 58, 60, 62 of the
extension frame 38 and allowed to dry The material 40 is then applied o
the surfaces 52, 54, 58, 60, 62 in an elevated temperature environment.
This chemical bonding procedure is further described in the product
information catalog BS10-2026J of the Lord Corporation, Erie, Pa.
It is also within the contemplation of this invention to manufacture the
compressible material 40 by molding, extruding or casting using the proper
adhesive or bonding agent to attach or bond and secure the compressible
material to the extension frame 38.
The present invention also provides methods to achieve the desirable
features of the present invention. One such method includes cutting strips
of the compressible material 40 out of a sheet with the proper dimensions
and of sufficient length to go around the circumference of the bottom
surface 54 and the outside surface 60 terminating underneath the flange
62. Alternatively, this strip of material may be cut sufficiently large to
extend all the way around the extension frame 38 to form a continuous
surface therearound which is necessary to achieve the desirable sealing
characteristics. The strip of compressible material is then secured to the
bottom surface and outside surface 54, 60 respectively by any conventional
known means particularly suited to the compressible material selected,
such as an adhesive molding in place by heat a | | |
