Technical field
[0001] The present invention relates to a ground cover according to the preamble of the
first claim.
Background art
[0002] A ground cover known in the art comprises an inner frame, arranged to be filled with
a ground surface material, e.g. paving stones, and an outer frame. The outer frame
is embedded in a ground surface layer and is arranged to support and laterally enclose
the inner frame. Provided between side walls of the inner and outer frames is a gap,
so that the inner frame is removably contained within the outer frame.
Disclosure of the invention
[0003] An aim of the present invention is to provide a ground cover with a longer life span.
[0004] This aim is achieved according to the invention with a ground cover showing the technical
characteristics of the first claim.
[0005] The invention provides a ground cover comprising an inner frame, arranged to be filled
with a ground surface material, and an outer frame, arranged to be embedded in a ground
surface layer and arranged to support and laterally enclose the inner frame, wherein
a gap of predetermined dimensions is provided between side walls of the inner and
outer frames so that the inner frame is removably contained within the outer frame.
The ground cover comprises a first seal at its top side, in a first seal material,
forming a resilient closure of the gap between the side walls of the inner frame and
the outer frame.
[0006] The first seal forms a resilient closure that prevents, or at least limits, dirt
entering the gap between the frames from above. The resilience of the closure offers
the advantage that dirt located at the closure can follow the movements of the inner
frame relative to the outer frame when the cover is under pressure, such as for example
from a car driving over it. The inventor has found that with a rigid, non-resilient
closure, dirt located at the closure can lead to deformations of the inner and/or
outer frame under such pressure, so that the closure is opened and dirt can freely
enter and fill the gap, with the result that the inner frame can no longer, or only
with great difficulty, be taken out of the outer frame. All of this can be prevented
by providing the first seal.
[0007] In a preferred embodiment, the first seal is provided at the inside of the outer
frame, and the inner frame is provided at the top with an outwardly extending flange
abutting the first seal. The inventor has found that providing the first seal at the
inside of the outer frame yields a better closure than providing the first seal at
the outside of the inner frame, because then the closure holds better under pressure
on the inner frame.
[0008] In a preferred embodiment, the first seal is a T-profile, wherein the upper part
of the T-profile is accommodated in a slot provided in the inside of the outer frame.
The inventor has found that this embodiment yields a precise and sturdy closure between
the two frames.
[0009] In a preferred embodiment, the first seal material is EPDM rubber. The inventor has
found that this material has the best elastic properties.
[0010] In a preferred embodiment, the outer frame has a bottom wall with a central opening,
and the ground cover comprises a second seal in a second seal material at the bottom
around the central opening, with which the inner frame rests upon the bottom wall
of the outer frame. This way, the ground cover has a seal around the central opening
that prevents or at least limits gases and scents escaping from e.g. an underlying
well covered by the ground cover.
[0011] In a preferred embodiment, the second seal is accommodated in a slot at the underside
of the inner frame. The weight of the inner frame, which is filled with ground surface
material, presses this rubber against the bottom wall of the outer frame, thereby
sealing off the underlying well substantially completely, allowing virtually no gases
or scents to escape.
[0012] In a preferred embodiment, the second seal material is EPDM rubber. The inventor
has found that this material has the best elastic properties.
Brief description of the drawings
[0013] The invention will be further elucidated by means of the following description and
the appended figures.
Figure 1 shows a cross section of a first embodiment of a ground cover according to
the invention.
Figure 2 shows a detail of figure 1.
Modes for carrying out the invention
[0014] The present invention will hereafter be described with respect to particular embodiments
and with reference to certain drawings, yet the invention is not limited thereto,
but only by the claims. The drawings presented here are only schematic and are non-limiting.
In the drawings, the size of some of the elements may be exaggerated, meaning that
they are not drawn to scale and are solely for illustrative purposes. The dimensions
and the relative dimensions do not necessarily correspond to actual reductions to
practice of the invention.
[0015] Furthermore, the terms first, second, third and the like in the description and in
the claims are used for distinguishing between similar elements, and not necessarily
for describing a sequential or chronological order. The terms are interchangeable
under appropriate circumstances and the embodiments of the invention can operate in
other sequences than described or illustrated herein.
[0016] Moreover, the terms top, bottom, over, under and the like in the description and
the claims are used for descriptive purposes, and not necessarily for describing relative
positions. The terms so used are interchangeable under appropriate circumstances and
the embodiments of the invention described herein can operate in other orientations
than described or illustrated herein.
[0017] The term "comprising" and terms derived from it, as used in the claims, should not
be interpreted as being restricted to the means listed thereafter; it does not exclude
other elements or steps. The term should be interpreted as specifying the stated features,
integers, steps or components as referred to, but does not preclude the presence or
addition of one or more other features, integers, steps or components, or groups thereof.
Thus, the scope of the expression "a device comprising means A and B" should not be
limited to devices consisting only of components A and B. It means that with respect
to the present invention, the only relevant components of the device are A and B.
[0018] The ground cover shown in figure 1 comprises an inner frame 1 and an outer frame
2. The inner frame comprises side walls 11,12 and a bottom wall 13, together forming
a bowl 14, provided to be filled with ground surface material of e.g. a ground paving
such as paving stones. The outer frame 2 comprises side walls 21,22 and a partial
bottom plate 23 with a central opening 24. The outer frame 2 is placed in a ground
surface layer over e.g. a well or piping to be covered (not shown). The dimensions
of the inner and outer frames are mutually adapted so that the outer frame encloses
the inner frame at the sides, wherein a gap 3 of predetermined dimensions is provided
between the side walls of the frames, so that the inner frame is removably contained
within the outer frame. The ground cover comprises a first seal 4 at its top side
and a second seal 5 at its bottom side.
[0019] The predetermined dimensions of the gap are preferably 1 to 10 mm (on either side
of the inner frame) for a cover height of 60 to 100 mm. In the embodiment shown here,
the gap 3 has a width of about 5 mm and the height is about 80 mm. The dimensions
may of course be adapted by the person skilled in the art according to the situation,
wherein for example a somewhat larger gap is provided for a larger and/or higher cover
to ensure removability. The dimensions stated here merely serve as examples and should
not be taken as limiting.
[0020] The first seal 4 comprises a T-profile 25 in a first seal material, e.g. EPDM rubber,
which together with an outwardly extending flange 15 at the top of the inner frame
1 forms a resilient closure meant to prevent or at least limit dirt entering the gap
3. The upper part of the T-profile is fully accommodated in a recess provided in the
wall of the outer frame, ensuring a sturdy mechanical anchoring of the first seal
4 in the wall of the outer frame 2. The first seal may however be implemented in other
ways as well.
[0021] The second seal 5 comprises a round shaped seal profile 16 and is accommodated in
a corresponding slot at the bottom of the side walls of the inner frame 1. The inner
frame 1 rests upon the bottom plate 23 of the outer frame 2 with this seal profile
16, such that it is compressed and can prevent or at least limit gases and scents
escaping from e.g. an underlying well covered by the ground cover. The second seal
is preferably also made from EPDM rubber. It may, however, have other shapes and be
made from other seal materials as well.
[0022] The inner frame 1 is further provided with lifting means at the top. In the embodiment
shown here, these lifting means comprise the threaded holes 17 as shown, into which
a T-shaped lifting member (not shown) is screwed for lifting the inner frame 1, and
in which an ordinary screw is inserted in use for filling the threaded hole. These
lifting means are preferably located in the corners of the inner frame, either on
both ends of a diagonal or in all four corners, depending on size. The lifting means
may however also be implemented in any other way known to the person skilled in the
art.
[0023] The inner frame 1 is executed as a rectangular assembly of side walls 11,12, fixed
to each other in the corners by welding, and a bottom plate 13, held with some tolerance
in holding elements 18 provided around the bottom plate. The side walls 11,12 are
preferably made from a first material, preferably a lighter material such as for example
aluminum, and the bottom plate 13 from a second material, preferably a sturdier material
such as for example galvanized steel. This way, a sturdy structure can be achieved
which is able to withstand any common load but is at the same time relatively light.
The tolerance between the two materials is for absorbing dilatation. In embodiments
of larger dimensions, the bottom plate can be provided with strengthening elements
at the underside of the bottom plate. In alternative embodiments, other materials
known to the person skilled in the arts may also be used. In alternative embodiments,
shapes other than rectangular may also be used.
[0024] The side and bottom walls of both the inner and the outer frame preferably, but not
crucially, extend substantially perpendicular to each other. This way, the frames
each provide vertical walls against which paving stones of a ground paving can be
laid. The side walls may however deviate from the vertical by a small angle, e.g.
1 to 2°.
[0025] The ground cover shown in figures 1 and 2 functions as follows.
[0026] The outer frame 2 is installed in a ground surface layer (not shown), e.g. a paving
made with paving stones, over e.g. a well or piping to be covered (not shown) in the
central opening 24. The inner frame 1 is filled with ground surface material, e.g.
the same paving, and placed in the outer frame 2, with the inner frame 1 resting with
seal profile 16 of the second seal 5 on the bottom plate of the outer frame 2. The
second seal 5 thus forms a closure that prevents or at least limits gases and/or scents
escaping from the underlying well or piping.
[0027] The gap 3 provided between the inner and outer frames to ensure removability of the
inner frame is closed at the top by means of the first seal 4, formed by the T-profile
25 and the outwardly extending flange 15 abutting each other. It is noted that the
inner frame 1 is substantially supported by the second seal 5; at the level of the
first seal 4, the components abut each other, though substantially without supporting.
The first seal 4 thereby forms a resilient closure that prevents, or at least limits,
dirt entering the gap 3 between the frames from above. The resilience of the closure
offers the advantage that dirt located at the closure can follow the movements of
the inner frame relative to the outer frame when the cover is under load, such as
for example from a car driving over it. The inventor has found that with a rigid,
non-resilient closure, dirt located at the closure can lead to deformations of the
inner and/or outer frame under such pressure, so that the closure is opened and dirt
can freely enter and fill the gap, with the result that the inner frame can no longer,
or only with great difficulty, be taken out of the outer frame. All of this can be
prevented by providing the resilient first seal.
1. Ground cover comprising an inner frame (1), arranged to be filled with a ground surface
material, and an outer frame (2), arranged to be embedded in a ground surface layer
and arranged to support and laterally enclose the inner frame, wherein a gap (3) of
predetermined dimensions is provided between side walls of the inner frame and the
outer frame so that the inner frame is removably contained within the outer frame,
characterized in that the ground cover comprises a first seal (4) at its top side, in a first seal material,
forming a resilient closure of the gap between the side walls of the inner and outer
frames.
2. Ground cover according to claim 1, characterized in that the first seal (4) is provided at the inside of the outer frame, and in that the inner frame is provided at the top with an outwardly extending flange (15) abutting
the first seal.
3. Ground cover according to any of the previous claims, characterized in that the first seal comprises a T-profile (25), wherein the upper part of the T-profile
is accommodated in a slot provided at the inside of the outer frame.
4. Ground cover according to any of the previous claims, characterized in that the first seal material is EPDM rubber.
5. Ground cover according to any of the previous claims, characterized in that the outer frame has a bottom wall (23) with a central opening, and in that the ground cover comprises a second seal (5) in a second seal material at the bottom
around the central opening, with which the inner frame rests upon the bottom wall
(23) of the outer frame.
6. Ground cover according to any of the previous claims, characterized in that the second seal is accommodated in a slot at the underside of the inner frame.
7. Ground cover according to any of the previous claims, characterized in that the second seal material is EPDM rubber.
8. Ground cover according to any of the previous claims, characterized in that the inner frame is an assembly of side walls (11,12) and a bottom plate (13), held
with some tolerance in holding elements (18) provided around the bottom plate at the
bottom of the side walls.
9. Ground cover according to claim 8, characterized in that the side walls are made from a first material, preferably a lighter material, and
in that the bottom plate is made from a second material, preferably a sturdier material.