Note: Descriptions are shown in the official language in which they were submitted.
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00937
A device for arranging shaft covers
The present invention relates to a device for arranging shaft
covers in accordance with the preamble of claim 1.
Conventional shaft covers for conduit-type sewers or the like
substantially consist of tubular elements to which an upper
frame part is attached which is used for receiving the cover.
In the case of a storm sewer such a cover is perforated,
whereas a substantially sealed cover is used for sewage
drains. The shaft usually rests at its lower end on the
generally horizontally extending sewer. It is unavoidable that
horizontal and vertical movements occur as a result of
fluctuations in temperature and, in particular, as a result of
frost and other influences in the road foundation. Road
traffic also constitutes a considerable burden. Conventional
rigid shaft systems can follow these movements only
inadequately or not at all. This leads both to damage to the
individual components as well as to situations in which the
cover is no longer flush with the road surface. This
constitutes a serious obstacle and a hazard for road traffic.
The respective repairs and exchange work cause relatively high
costs.
From WO 82/04276 an arrangement is known for a shaft cover in
which a frame part for a shaft cover is anchored by a dome
shaped holding section in an upper layer of the road
foundation. At its lower side the frame part is provided with
a downwardly projecting sleeve which encloses a shaft pipe
with play, so that an axial movement is possible within a
certain margin. Any changes in the soil level which are caused
by frost can be partly compensated in this manner. If in
addition to the changes in level there are displacements
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parallel to the road surface, such displacements cannot be
compensated by this design. Moreover, the pipe that slides in
the sleeve can get stuck, thus preventing the device from
performing its intended purpose.
Furthermore, from GB 2 194 981 A a housing for a water shut-
off valve is known which consists of a base plate, a grooved
pipe and an upper section which carries a cover. In the case
of this maintenance shaft, the grooved pipe mainly fulfills
the task of improved anchoring in the soil in order to prevent
any inadmissible load on the pipe. The upper part is provided
to encompass the pipe. It is not connected with the pipe
however which extends freely into said upper part. Although
such a design may be suitable for maintenance shafts of water
valves and the like, it is certainly not useful in a general
manner for sewer covers. Moreover, there is always the problem
in connection with a grooved plastic pipe, as is proposed in
this document on the state of the art, that a sufficiently
stiff pipe that can withstand the pressures of the soil is
only insufficiently flexible in order to be able to absorb the
occurring soil movements. If the pipe is provided with a
sufficiently flexible design however to fulfil this task, the
problem of lack of strength will arise, thus giving rise to
fears that the shaft will collapse when subjected to road
traffic.
Shaft covers are further known from SE 403 919 A and SE 384
238 A in which telescopically extendable elements are
provided. Although it is possible with such telescopic guide
means to compensate the changes in the level of the shaft
cover with respect to the components that are fixedly anchored
in the soil, radial displacements on the other hand will lead
to problems. Moreover, it is not easily possible with such
systems to achieve an inclined installation position in the
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case of inclines of roads and the like. Moreover, the threat
of jamming of the telescopic guide means exists, which my lead
to functional impairments.
It is the object of the present invention to avoid such
disadvantages and to further develop a shaft cover in such a
way that even in the case of strong fluctuations in
temperature, frost, heavy road traffic and the like the flush
position of the cover with the road surface is ensured at all
times . The shaft cover shall be easy to make at low price and
it is to be possible to provide a large number of different
applications with a small number of different components. It
is to be possible to compensate not only vertical
displacements, but also displacements in the radial direction
to a certain extent.
These objects are achieved in accordance with the invention by
an arrangement according to the characterizing part of claim
1.
The relevant aspect in the invention is that not only a
telescopic guidance of different components is provided, but
also that said components are provided with a limited inner
elasticity so as to enable the same to follow soil movements
and crushing to a certain extent. The anchoring part and the
compensating ring are preferably made of a suitable plastic
material. The particular advantage of the invention is that
depending on the required height of the system the number of
compensating rings can be chosen in a suitable way. In the
smallest possible variant the anchoring part is placed
directly on the connecting part. If a larger height is to be
overcome, compensating rings are inserted in the required
number between the connecting part and the anchoring part. In
this way only three different components need to be stored for
the flexible section, thus simplifying handling and reducing
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manufacturing costs. As a result of the preferably elastic
arrangement of the rings it is possible to compensate not only
the displacement in the axial direction, but also to absorb
and compensate displacements in other directions. The
arrangement in accordance with the invention permits providing
an angular displacement between the anchoring part and the
connecting part in the case of an incline.
It is particularly favorable when the connecting part
comprises at its upper end at least one holding claw which is
intended to engage in a respective recess of the anchoring
part or the compensating ring. Since it is possible in this
way to connect in a captive manner the connecting part and the
anchoring part located above the same or, optionally, the
compensating ring, the mounting is simplified to a
considerable extent. It is possible to produce the connection
between the individual rings by latching. It is similarly
possible to produce a connection by rotation in the manner of
a bayonet catch.
It is provided in a particularly preferred embodiment that a
plate-shaped, upwardly facing extension is provided integrally
on the outer circumference of the anchoring part. In this way
the anchoring part is securely embedded in the ambient soil
and can follow the respective movements in an unobstructed
way.
A particularly favorable connection of the compensating rings
among one another or with the anchoring part is achieved in
such a way that the compensating ring is provided in its upper
area with two concentric grooves.
Solutions are known in which the frame part, i.e. the
uppermost component in which the shaft cover is embedded, is
provided with an anchoring ring which is provided with a
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' design so as to be flush with the road surface. It has proved
to be particularly more appropriate; however, when the
anchoring ring is anchored slightly below the road surface and
is thus encompassed on all sides by the road surfacing and is
held by the same.
In order to enable the easiest possible raising of the shaft
cover after the application of an additional road surfacing
layer, it may be provided in particular that an intermediate
ring is provided which is designated to be placed on the frame
part and that the intermediate ring is provided with an
outwardly extending anchoring ring. Within the terms of the
invention it is possible that intermediate rings of different
thickness can be provided. Depending on the thickness of the
additionally applied road surfacing, one or several
intermediate rings are inserted in order to raise the shaft
cover accordingly.
The penetration of soil or stones into the mutually movable
parts can securely be prevented by providing a bellows. The
compensating rings can represent a reinforcement of the
bellows in such a solution and support the same against the
soil. It is also possible to reinforce the bellows per se by
inserted steel rings. In another possible variant a foil
encompassing the rings can form the protection against the
penetration of foreign bodies.
The invention is now explained in closer detail by reference
to the enclosed drawings, wherein:
Fig. 1 shows a sectional view of a device in accordance
with the invention in the installed state;
Fig. 2 shows an exploded view of the individual
components of the device in accordance with the
invention;
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Fig. 3 shows a view of an embodiment of an intermediate
ring from above;
Fig. 4 shows a sectional view along line IV-IV in Fig.
3;
Fig. 5 shows a further embodiment of the invention in a
sectional view;
Figs. 6 through 8 show sectional views which explain the
function of the invention.
An upper frame part 1 is configured for receiving a cover not
exhibited in Fig. 1. The frame part 1 rests on an anchoring
part 20 which is provided with two concentric ring sections 21
between which a ring-shaped recess 22 is formed. A plate-
shaped, radially outwardly facing extension 23 is used for
supporting the anchoring part 20 against the ambient road
foundation 10b, i.e. the subgrade. A compensating ring 30 is
arranged below the anchoring part 20, which compensating ring
is provided analogously with two ring sections 31 between
which a ring-shaped recess 32 is formed. A ring section 41 of
a connecting part 40 engages in said recess 32, which
connecting part rests on a partly shown shaft ring 50.
In order to avoid deinstalling the frame part 1 during the
application of an additional road surfacing 11, an
intermediate ring 9 is provided which can be inserted into the
frame part 1. If necessary, a second, thinner intermediate
ring 9a can be inserted in addition so as to achieve a precise
leveling with the road surface 51.
Fig. 2 shows the individual components of the device in
accordance with the invention in an exploded view on an
enlarged scale. The anchoring part 1 comprises an anchoring
ring 15 approximately in the center of its outer
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circumference, which anchoring ring is equipped with
breakthroughs 16 and forms the retaining element within the
terms of the present invention. This ensures a secure hold of
the anchoring part 1 in the ambient road surfacing 10a.
Furthermore, Fig. 2 shows in the upper part next to the
described intermediate rings 9 and 9a a further intermediate
ring 9b of a different height. Since it is not possible due to
the low height of the intermediate rings 9a and 9b to form the
recess for the receiver of the cover as in ring 9, spacer
rings 9aa and 9bb are provided which have the same height as
rings 9a and 9b and which are placed on the rest for the sewer
cover.
If the heights of the intermediate rings are chosen with 2, 3
and 7 cm for example it is possible to cover with merely two
intermediate rings at distances of 1 cm any height of the
additional road surfacing in the usual range of 2 cm to 10 cm
or more. Despite the possibility of adaptation to all possible
situations it is possible to minimize the required stock in
store.
The connecting part 40 comprises a holding claw 42 at the
upper end of its ring section 41. Claw 42 engages in a
respective recess 34 in a ring section 31 of the compensating
ring 30. In installation cases without the compensating ring
30 the claw 42 engages in a recess 24 of a ring section 21 of
the anchoring part 20.
A centering ring 46 is attached in the lower region of the
connecting part 40 in order to ensure a secure fit on the
shaft ring 50. An outwardly projecting part 47 is used to
receive the soil pressure in order to keep the connecting part
40 in its position.
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It is further shown in Fig. 2 that in the upper part of the
compensating ring 30 there are recesses 35 in order to receive
the ends of the ring sections 21 of the anchoring part 20.
Figs. 3 and 4 show an embodiment of an intermediate ring which
is designated with 9a'. The difference to the intermediate
ring 9a of Fig. 2 is that retaining projections 59 are
provided on the outer circumference in order to improve the
anchoring of the intermediate ring 9a'.
Fig. 5 shows an embodiment of the invention in which a bellows
4 is provided between the frame part 1 with a bearing ring 3
and a connecting part 6. The bellows 4 is composed of
truncated sections which show a sequence in alternating
orientation and are reinforced by steel rings 5. Compensating
rings which are not shown in Fig. 5 can be provided within the
bellows 4. The entry of foreign bodies can be securely
prevented by the bellows 4. Reference numeral 2 indicates a
shaft cover and numeral 7 indicates holding brackets.
Figs. 6 through 8 explain the mode of operation of the present
invention. Fig. 6 shows the state of an arrangement consisting
of an anchoring part 20, a compensating ring 30 and a
connecting part 40 where said parts are pushed far into one
another. The compensating ring 30 is fixedly held by the
anchoring part 20 in such a way that a claw 36 of the
compensating ring 30 rests on a stop 28 of the anchoring part
20, so that both parts 20 and 30 are rigidly connected with
one another. The connecting part 40 is pushed far into the
compensating ring 30 and claw 42 is distanced from a stop 38
of the compensating ring 30. Fig. 7 shows in a mirrored view
the opposite situation in which the individual part are pulled
as far apart as possible. In contrast to Fig. 6 the claw 42 of
connecting part 40 rests on the stop 38 of the compensating
ring 30.
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Fig. 8 shows that an inclined position of the anchoring part
20 as compared with the connecting part 40 is possible. A
situation is shown in which no compensating ring is used. The
left half of Fig. 8 shows that the anchoring part 20 is in a
maximally lowered state, so that the same rests directly on
the connecting part 40 in the lower zone of the stop 28. At
the opposite side, however, claw 42 and the stop 28 are in
engagement . In this way an inclination angle ~ of 5 ° and more
can be achieved in the embodiment of Fig. 8.
The device in accordance with the invention allows producing a
shaft frame at low cost which is always flush with the road
surface. The device can be mounted quickly and cost-
effectively and can be adjusted in a similarly quick and cost-
effective manner to any new road surfacing level when a repair
or renewal of the road surfacing is performed. The present
invention is suitable both for the new construction as well as
the improvement of existing shafts.
Since the actual frame part 1 is mounted only immediately
before the application of the road surfacing, a simple
compaction of the grading material is possible, with the
anchoring part 20 being substantially flush with the surface
of the road foundation. The operation of the respective
vibrators or rollers is therefore practically not limited by
the sewer holes. The device in accordance with the invention
is waterproof, frost- and heat-resistant and is comparatively
light in weight.
