EP3199710B1

EP3199710B1 - Manhole closure

Info

Publication number: EP3199710B1
Application number: EP17153542.0A
Authority: EP
Inventors: Lars-Olof Ekman; Ole Kristian Aasvestad
Original assignee: Furnes Jernstoperi As
Current assignee: Furnes Jernstoperi As
Priority date: 2016-01-27
Filing date: 2017-01-27
Publication date: 2018-03-07
Anticipated expiration: 2037-01-27
Also published as: EP3199710A1; DK3199710T3; NO3199710T3

Description

Technical field

The present invention relates to a closure, intended to placement over the opening in a manhole having an oblong, mainly rectangular form.
Manholes are used where cleaning access and air access to the sewers is needed or wanted. Furthermore manholes are used in connection with cable wells, wherein a larger opening for equipment, assembly and disassembly is desirable. Manholes need to be openable in order to achieve access to the well. One or more operators must have the possibility of descending through the well in order to regularly inspect and possibly repair the underground lines, mainly sewer- and water lines and electrical and IT cables. The access conditions in connection with descending into the manholes are often narrow and accordingly there is a need for extending the opening area in the manhole in order to improve space allowances.
The present invention relates to a manhole having a relatively large descending opening. If the relatively large opening of the manhole has to be covered by one closure, this will impose a major weight of the closure, whereby lifting equipment will have to be used in connection with inspection of the well.
It will thus be advantageous to be able to use a cover, not necessitating special lifting equipment in connection with mounting, servicing and inspection of the manhole.
From the description in DE102004036647 it is known to have a cover comprising to rectangular closures and an oblong frame surrounding a rectangular oblong opening. The two closures are placed side by side. A diagonal cross bar is connected to the frame between the two closures forming a contact surface on the underside of the closures. The cross bar is dismountable from the frame in order to achieve full passage through the frame.
A disadvantage of the solution in accordance with DE102004036647 is that the rectangular closures and the cross bar causes a storage need for the closures and the cross bar, which will be problematic for firms servicing a large number of manholes.

Disclosure of the invention

The purpose of the invention is to provide a cover for a mainly rectangular opening, with the possibility of using common circular closures in order to keep stocking at a minimum.
Furthermore it is the purpose of the invention to provide a cover, where the weight of the unit is kept at a level not necessitating separate equipment in connection with assembling, servicing and inspection of manhole, cleaning well and/or inspection well.
The solution in accordance with the invention comprises at least two circular manhole closures and at least one central section, a frame (40) being designed to support at least two manhole closures (2) whereby the frame (40) is mainly rectangular and designed having half circular ends, and the central section (3) being designed to being placed between the manhole closures, the central section (3) comprising two planar end surfaces and two identical opposite side surfaces (30) in the form of circular sections complementary to and abutting the circumference of the manhole closure.
This provides an opportunity of using a number of common circular manhole closures for larger openings compared to the openings for which a single closure is intended for.
The central section is only minor space demanding compared to the total opening area of the manhole.
In accordance with the invention it is possible to use a closure having a locking system known as such, and designed so that the closure cannot be sucked or pressed out of the frame due to overpressure from the sewer system or the suction formed when a truck passes over the closure.
The locking system can comprise a resilient arm having a wedge shaped cam designed to engage the frame. The resilient arm is fixed to the underside of the manhole closure and can be released by mean of a rod or the like, led through a hole in the closure at the level of the resilient arm.
The term "closure" will in the following be used for describing the element, which is used for covering a part of the opening in the manhole. The term "manhole closure" will in this connection be equivalent to the term "closure".
Further to "manholes", the present invention will also be used for inspection wells, cleaning wells, flushing wells and corresponding types of wells.

Short description of the drawings

Fig. 1 shows a cover, where the closures are placed in the frame,
Fig. 2 shows a central section seen from above,
Fig. 3 shows the central section showing the stiffenings on the underside of the central section,
Fig. 4 shows a frame in accordance with the present invention,
Fig. 5 shows a first embodiment, in which the frame comprises an upper frame and a lower frame,
Fig. 6 shows a second embodiment for use at an existing rectangular well, wherein the cover plates are used for sealing the corners of the well.

Fig. 1 shows that the cover (1) is a construction comprising a frame and two closures, able to cover an access hole for a underground line system (not shown in the figures). A rectangular box (5) is used for illustrating one example of a rectangular space, which has to be covered. In the following the rectangular box (5) is used for illustrating a manhole or the top ring, which can be used in connection with adjustment of the height of the well cone.
The closures (2) shown in the figures can be pressure tight closures, which are able to withstand the water pressure down from the well as such. The closures (2) will in accordance with the present invention be mounted in the frame, which is fastened to the underlying well. The closures will comprise a locking arrangement, which is able to secure against overpressure from the well.
Fig. 1 shows the cover (1) in accordance with an embodiment, in which two circular closures (2) are placed in a frame (40). The frame (40) is designed such that the frame can support the two closures (2). Furthermore the closures are placed with a mutual distance.
As shown in fig. 1, the cover (1) further comprises a central section (3), placed between the two closures. The central section (3) comprises two planar sides providing the possibility of mounting the central section in the frame (40). The central section (3) is provided with two opposite sides (30) each comprising a circular section complementary to and abutting a part of the circumference of the manhole closure.
The frame (40) is mainly rectangular having two half circular ends. The frame (40) is a floating frame, which is continuously adjustable in its height. As shown in fig. 1, two cover plates (43) can be used for securing the placement of the frame (40) on top of the rectangular well opening. Furthermore the frame can be divided in two or more sections (11, 12). The function of the cover plates (43) will be described in the following. In a second embodiment the frame can be formed in one piece.
The frame (40) can be a floating type frame and can thus be adjusted continuously within the range of the skirt height. The flange of the frame is supported by asphalt or other suitable material. The flange (11, 12) can take up traffic loads and distributes the load into the material surrounding the bowl and partly to the bowl. The use of floating frames in asphalt is prior art as such and will thus not be described further.
Fig. 2 shows a central section (3) formed with two identical opposite side faces (30) each of said opposite sides (30) comprising a circular section, complementary to and abutting the circumference of the individual closure (2). The central section (3) comprises two planar end faces (32) such that the central section can be mounted in the frame (40).
When the central section (3) is placed or fixed in the frame (40), the geometrical form of the opposite half circular ends of the frame (40) and the opposite sides (30) of the central section (3) respectively form two circular manholes, which can be covered by the closures (2).
Furthermore fig. 2 shows that the central section can comprise a recessed abutment surface (31), extending along the length of both opposite sides (30). When the central section (3) is mounted in the frame (40), the two recessed abutment surfaces (31) on the central section (3) will function as support for each of the closures. Dependent on the length of the recessed abutment surface (31) and thus the length of the circular section, the individual closure will be supported along approximately one half of the circumference of the closure.
Fig. 2 shows that the central section (3) comprises one or more lifting rod openings which are designed such that a lifting rod or the like can be introduced and engaged therewith. Lifting rod openings (33) provides the possibility of lifting and handling the central section. Lifting rod openings (33) are used in connection with installation and inspection of the manhole. The lifting rod openings (33) have a mainly rectangular opening, extending in an inclined angle from the upper side of the central section and down towards the underside of the central section (3).
Fig. 3 shows the underside of the central section (3), showing that the central section (3) comprises one or more reinforcements (35). In fig. 3 three reinforcements are provided on the underside of the central section (3), and the reinforcements extends between the two planar end surfaces (32).
Furthermore fig. 3 shows a special embodiment, in which the two planar end surfaces (32) comprises two projections (32), each projection (32) being releasably fixed to the central section (3) e.g. using a bolted connection (321).
Fig. 4 shows an embodiment of the invention, in which the frame (40) comprises two or more sections (11,12), which sections (11,12) can be mutually connected and thus provide a frame having an internal oval geometry. In the embodiment shown, the two sections (11,12) are mutually connected using a row of bolted connections (401,402,403,404). In an embodiment, not shown, the frame is provided in one piece.
The frame can comprise a flange (15), extending perpendicularly along the whole circumference of the frame (40). The frame (40) can comprise two recesses (16,17) formed for supporting the central section (3). The recesses (16,17) extend along a part of the inner side of the frame (40).
Fig. 4 shows that the frame is formed with a recessed abutment surface (13,14) along a part of the periphery of the circular part of the frame. Each of the recessed abutment surfaces (13,14) are formed for supporting one closure along more than half of the circumference of the closure.
Fig. 5 shows a first embodiment in accordance with the invention, in which the cover (1) comprises a frame and one central section (3), which can be placed between the two closures (2). The central section (3) is corresponding to the construction, which is shown in fig. 2.
The frame comprises an upper frame (41) and a lower frame (42). The upper frame (41) is equivalent to the construction, which is shown in fig. 4. The lower frame (42) comprises a plate (422) having an opening, which is mainly rectangular and formed having half circle formed ends. A cylindrical piece (421), extending perpendicular to the plane of the plate, is fixed along the opening. The lower frame (42) is formed to secure that the upper frame (41) is freely movable up and down in relation to the underlying well (5), i.e. functioning as a floating frame. Thus loads are transmitted from the upper frame (41) via the flange down to the supporting part of the material around the bowl.
The upper frame (41) can comprise at least two sections (11,12) each having a recessed abutment surface (13,14) along a part of the periphery, more specifically along the circular part of the frame. The recessed abutment surface (13,14) is formed to support a closure along more than half of its circumference.
Furthermore the lower frame (42) can comprise several lifting lugs (423) attached to the plate (422), where each lifting lug (423) may be attached close to each corner of the plate (422). The lower frame (42) may be divided into two or more sections (425,426), which may be mutually connected.
Fig. 6 shows a second embodiment, in which the cover (1) comprises a frame and a central section (3), which can be placed between the two closures (2). The central section (3) corresponds to the construction shown in fig. 2.
In the embodiment shown each of the cover plates (43) may comprise a plate having a circular section adapted to the geometry of the frame and the geometry of the well.
The frame (41) can comprise at least two sections (11,12), which are formed with a recessed abutment surface (13,14) along a part of the periphery of the circular part of each section. The recessed abutment surface (13,14) is formed for supporting a closure along more than half of the circumference of the closure.
The primary function of the cover plates (43) is to seal the corners of the underlying well such that gravel and sand does not fall into the well. Furthermore the cover plates (43) will secure that the load is transmitted from the frame (40) to the underlying well (5) and the surrounding material. The cover plates (43) can have the further characteristic that they dampen the vibrations provided when a vehicle passes over the cover.
The cover (1) shown in fig. 5 comprises a circumferential gasket (61), which in use is placed and mounted in the upper edge of the lower frame (42).
The figures 5-6 show that one or more gaskets (7) can be placed between the central section (3) and the frame (41) and around the closures. Hereby is achieved, in accordance with the invention, a cover which is specially suited for areas, where there exist a risk of overflow, as the closures also are tight against outflowing water.
By placing the gaskets (7) around the closures (2) and along the two planar sides (32) of the central section (3), noise from vibrating closures and/or central section(s) can be prevented. The gasket on the central section (3) can be fixed by own force, due to the gasket being formed from a flexible material. In an embodiment, not shown, the gasket can be fixed by using screws or equivalent fasting elements.

List of parts with reference to the figures

Cover (1)
Frame sections (11,12)
Recess (16,17)
Closures/manhole closures (2)
Central section (3)
Opposite sides (30)
Recessed abutment surface (31)
Projection (32)
Lifting rod opening (33)
Bolted connection (321)
Frame (40)
Bolted connection (401,402,403,404)
Upper frame (41)
Lower frame (42)
Cover plates (43)
Cylindrical piece (421)
Plate (422)
Sections (425,426)
Manhole (5)
Gasket (61)
Gasket (7)

Claims

Cover for a manhole having an oblong, mainly rectangular form, characterized by comprising at least two circular manhole closures and at least one central section (3), a frame (40) being provided for supporting at least two manhole closures (2), said frame (40) being mainly rectangular and formed with half circular ends, and said central section (3) being provided for placement between the manhole closures, said central section (3) comprising two planar end surfaces and two identical opposite side faces (30) in the form of circular sections, which are complementary to and abutting the circumference of the manhole closures.
Cover (1) in accordance with claim 1, characterized by said central section (3) comprising a recessed abutment surface (31) extending along the length of both opposite sides (30).
Cover (1) in accordance with claim 1, characterized by the frame (40) comprising two or more sections (11,12).
Cover (1) in accordance with claim 3, characterized by said frame (40) comprising a flange (15) extending perpendicular along the circumference of the frame (40), said frame (40) comprising a recess (16,17) formed to supporting the central section (3), said recess (16,17) extending along a part of the inner side of the frame (40).
Cover (1) in accordance with claim 3 or 4, characterized by each section (11,12) of the frame (40) being formed with a recessed abutment surface (13,14) along part of the periphery of the circular part of each section, said recessed abutment surface (13,14) being formed to support one manhole closure along more than half of the circumference thereof.
Cover (1) in accordance with any of the preceding claims, characterized by the central section (3) may comprise two projections (32), each projection (32) being formed such that the projections (32) are releasably attached to the central section (3) e.g. using a bolted connection (321).
Cover (1) in accordance with any of the preceding claims, characterized by the central section (3) comprising one or more lifting rod openings or openings (33), which are formed such that a lifting rod or the like can be inserted and engage therewith.
Cover (1) in accordance with any of the preceding claims, characterized by the central section (3) comprising one or more reinforcements (35) said reinforcements being placed on the underside of the central section (3).
Cover (1) in accordance with claim 1 or 3, characterized by the frame (40) comprising an upper frame (41), continuously adjustable in relation to the lower frame (42), said lower frame (42) comprising a plate (421) having an opening, a cylindrical piece (421) being placed at the opening, said cylindrical piece (421) extending perpendicular in relation to the plane of the plate.
Cover (1) in accordance with any of the preceding claims, characterized by the lower frame (42) comprising several lifting lugs (423), attached to the plate (422), each lifting lug (423) possibly being attached close to each of the corners of the plate (422).
Cover (1) in accordance with any of the above claims, characterized by the lower frame (42) may be divided into two or more sections (425,426).
Cover (1) in accordance with claim 1 or 3, characterized by the frame (40) abutting two cover plates (43), each cover plate (43) comprising a plate having a circular section, which is adapted to the geometry of the frame (40).
Cover (1) in accordance with any of the claims 10-11, characterized by a gasket (6) positioned between the upper frame (41) and the lower frame (42) or between the upper frame (41) and the cover plates (43).
Cover (1) in accordance with any of the above claims, characterized by one or more gaskets (7) being placed between the central section (3) and the frame (40).
Cover (1) in accordance with any of the above claims, characterized by a resilient arm being attached to the underside of the manhole closure and the resilient arm being provided with a wedge formed cam which can engage the frame.
Cover (1) in accordance with claim 10, characterized by the lower frame (42) may be formed in one piece.