EP2543773A1 - Manhole cover - Google Patents

Abstract

The cover (1) has a cup-shaped bottom (3) made of plastic i.e. glass-fiber reinforced plastic, that is reinforced with non-directional fiber mats. A concrete filling (2) is filled in the bottom. Lifting handles (5) are provided in recesses (4) of the concrete filling. The lifting handles are arranged to face each other corresponding to a mid-point of the cover. The lifting handles are formed from a wire, where two ends of the wire are anchored in the concrete filling. A center part of the wire is extended through the recesses.

Description

The invention relates to a manhole cover according to the preamble of claim 1.

From the GB 2 145 444 A , which forms the closest prior art, a manhole cover is known, which consists only of the two components of a floor and a filling. As material for the bottom of the manhole cover, the same material is preferably used as for a manhole, which is to be closed with the manhole cover, is mentioned as an example of high density polyethylene. The manhole serves as access to the sewer system for inspection purposes. Where the manhole cover can be arranged and what loads it withstands is not mentioned.

From the DE 298 01 640 U1 is a generic foreign manhole cover known. This manhole cover has at the bottom of an outer shell made of sheet metal, in which then the actual bottom is poured, which has a certain layer thickness, and in which case the filling is poured into the ground. This overall three-layer structure of the manhole cover is complex in terms of production technology. The components or materials used are relatively expensive, so z. B. the outer shell provided as a lost molding made of sheet metal, and the bottom is either made of cast steel or - in contrast, larger dimensions - made of polymer concrete. The filling also consists of Polymer concrete. The manhole cover is to be arranged in roadways and is designed for correspondingly high load capacities due to a high volume of traffic, high mechanical loads and aggressive weather conditions.

From the US 5,123,776 is a manhole cover known, which is designed as a filled hollow body. A shell encloses the filling on all sides, so that the filling must be introduced through a filling opening in the shell. The shell is preferably made of polyethylene, and the filling is preferably made of concrete. Lever as are designed as a substantially U-shaped, downwardly open bracket. They can be pulled out of the manhole cover in a vertical direction so that they can be picked up to lift the manhole cover. In the lowered state of rest, the lever pockets each dive into a recess which is provided in the surface of the manhole cover. The manufacture of the manhole cover is complicated because a hollow body must be filled, the openings of the hollow body, which are required for the vertical mobility of the lever ashes, either complicate this filling, or later, after hardening of the filling, the manhole cover must be repeatedly pierced, to create channels through which the lever pockets can extend.

From the US 4,974,992 a lid is known which does not serve as a manhole cover, but serves to cover trenches in road surfaces, and which is designed as a metal plate. The lid is used when the excavation work is stopped and the road surface is opened for traffic. In order to withstand the traffic loads, the metal plates are dimensioned accordingly stable and therefore heavy. To simplify your handling, Omega-shaped lever pockets are provided, which are rotatably mounted at its two ends in the cover plate and from a down-hanging rest position in an upright Use position can be pivoted in which they protrude above the surface of the lid upwards.

From the US 4,801,483 For example, a lid having a core with a cell structure and an outer closed cladding layer of a fiber reinforced resin is known. The lid should expressly endure high dynamic loads, so that z. B. in traffic, the vehicles can drive over the lid. The core can, for. B. consist of several Balsaholzblöcken, and the cladding layer of a glass fiber reinforced epoxy or polyester resin. The manufacture of the lid is complicated because two separate parts of the coating layer are produced. A first part of the cladding layer forms a trough, in which then the individual components of the core are inserted. Subsequently, the core is covered with the second part of the cladding layer. It should be noted that both parts of the cladding layer must be bonded together at all points of contact that they have with each other and with the core structure, and that any air pockets must be avoided to provide a substantially monolithic mass. Tools for lifting the lid are not provided, but rather the lid has anchor holes which allow the insertion of ground anchors, so that the lid can be fixed by means of these ground anchors to the ground.

In many cases manhole covers outside of roads are required. For example, inspection and maintenance shafts may be provided on private residential land, e.g. As in garage entrances to allow access to the house connections of the sewer for cleaning or inspection purposes. A mechanical load by heavy trucks is just as little given here as a high volume of traffic or a high road salt load in winter. Conventional manhole covers are therefore often overqualified for these applications and because of their complex production or unnecessarily expensive because of the expensive materials used.

The invention has for its object to improve a generic manhole cover to the effect that this is possible to produce inexpensively.

This object is achieved by a manhole cover with the features of claim 1.

The invention proposes, in other words, to create a production-optimized manhole cover, which does not necessarily have to withstand particularly high loads, as is the case for example in traffic, but for example in driveways, on private land u. Like. Can be used and which consists of a minimum number of components and therefore is accordingly economical to produce.

• Erstens ist in Art einer verlorenen Schalung der Boden vorgesehen, der schalenförmig ausgestaltet ist und in den daher das Material der Füllung schneller und unkomplizierter eingefüllt werden kann als in eine Hohlform, die im Wesentlichen ringsum geschlossen ist.
• Als zweite Komponente ist die Füllung aus Beton vorgesehen, welche in diesen Boden gegossen wird. Der Gießvorgang selbst kann einfach und schnell durchgeführt werden, und Beton ist ein preisgünstiger Werkstoff, insbesondere da kein Spezialbeton verwendet wird, wie z. B. Polymerbeton, sondern ausschließlich mineralischer Beton.
• Um den Deckel möglichst einfach handhaben zu können, ist als dritte Komponente eine Hebelasche vorgesehen, die in an sich bekannter Weise versenkt innerhalb der Füllung angeordnet ist.

The proposed manhole cover consists essentially of only three different components:

• First, in the form of a lost formwork, the floor is provided, which is designed shell-shaped and in which therefore the material of the filling can be filled faster and less complicated than in a mold, which is substantially closed all around.
• As a second component, the filling is made of concrete, which is poured into this soil. The casting process itself can be done easily and quickly, and concrete is a low-cost material, especially since no special concrete is used, such. B. polymer concrete, but only mineral concrete.
• In order to handle the lid as easy as possible, a lever ashes is provided as the third component, which is arranged sunk in a conventional manner within the filling.

The formwork initially required when pouring the filling later also forms the bottom of the finished manhole cover and serves as a protective layer and, however, only to a small extent, as a mechanical reinforcement of the manhole cover. In view of the fact that the proposed manhole cover can be used in particular on low-traffic land, especially residential land, a most durable connection of the soil with the filling is also desirable for aesthetic reasons alone. A gap between the floor and the filling can be gradually increased by penetrating and possibly freezing water. Apart from the fact that thereby the manhole cover could be mechanically damaged, such a gap can absorb dirt and plants can root in this gap, so that the manhole cover can give an undesirable in the living area, neglected impression or requires increased care. Therefore, the prefabricated, cup-shaped bottom is designed rough on its inner side facing the filling. For this he can either be left rough in the production of the soil, or he may optionally be roughened after the preparation of the soil.

In addition to the roughness of the bottom inside, an adhesion promoter between the bottom and the filling is proposed, so that a secure, gap-free connection of the soil is ensured with the filling.

According to the proposal, the soil has a layer thickness of at most 5 mm. As a result, on the one hand sufficient inherent stability of the soil is guaranteed to make it suitable as a casting mold, so as a lost formwork for the concrete filling. On the other hand, the most economical production of the manhole cover is supported by this comparatively low material thickness of the soil.

According to the proposal, the floor consists of glass fiber reinforced plastic. In this way, not only a mold for the concrete of the filling is created, but due to its material properties, the soil can also contribute to the strength and compressive strength of the manhole cover contribute. In addition, the soil is economical to produce, so that it can easily remain as a lost formwork even after pouring the filling at this. A coating, impregnation or other treatment of the concrete filling on its underside is therefore not required to protect against influences that act on the manhole cover from the shaft. Rather, the manhole cover is usable without post-processing, after the concrete filling is cured in the bottom shell.

As plastic, a thermosetting plastic is used. This has sufficiently good mechanical properties and a very good economy.

Optionally, a further lever ashes may be provided, so that two diametrically opposite points are provided for handling the manhole cover and the manhole cover can be raised or lowered as simply as possible and without jamming. Both lever ashtrays can be made as equal parts, so that only two different types of parts must be prefabricated, namely the ground and the lever ashes, with a bottom and one or two lever ashes are used for each manhole cover. The filling itself need not be prefabricated as a component, but is poured in a flowable state into the soil, which thus forms the formwork for the concrete filling.

Due to the very small number of components having the manhole cover, therefore, only comparatively few components must be prefabricated, which simplifies the manufacture of the manhole cover. Also, the warehousing or transportation costs for prefabricated components are reduced. In addition, in the production of the manhole cover, a further simplification of the manufacturing process finally results in that, accordingly, only a small number of components have to be connected to one another in order to form the manhole cover, so that overall a very economical production of the manhole cover is made possible.

Due to the economic production of the manhole cover this is particularly suitable for applications where not the highest load capacity of the manhole cover, but in particular the cost of the manhole cover are in the foreground. For example, the proposed manhole cover can be designed for a load of 15t to 20t, in contrast to, for example, manhole covers that are used on public roads and can be loaded up to 40t. In particular, it may be advantageously provided that the manhole cover is technically designed for a load of only 5 t, so that correspondingly inexpensive materials can be used or the layer thicknesses of the floor or of the filling can be correspondingly low. For example, in the context of official German load classes, the technically possible load capacity of 5t means a license of up to 1.5t for use in public areas, eg. B. on sidewalks or the like, and for a passability with cars on private, non-public property or garage entrances is sufficient in most cases. In order to ensure the load capacity of 5t, the manhole cover can advantageously be structurally designed in terms of its materials and layer thicknesses that it is destroyed only at a load of 6t, said force at which the destruction occurs, is referred to as a bursting force.

The cost-effective production of the manhole cover can be advantageously supported by the fact that not only one, but two lever pockets are provided, which are arranged diametrically opposite one another. This way you can the lid can be raised or lowered without jamming, which reduces the burden of the manhole cover compared to the use of only a single lever as, for example, edge loads are reduced by an oblique orientation of the lid. The load on the individual lifting lugs and the places where the lifting lugs are anchored in the filling is also reduced by using two lifting lugs. Despite the higher use of material can be made ultimately more economical by the arrangement of two lever ashes of the manhole cover in the final analysis more economical than using a single lever ashes, the manhole cover must be designed for these only lower loads.

Advantageously, it can be provided that a lever ashes are formed from a wire, preferably a stainless steel wire whose two ends are anchored in the filling, wherein in the filling a trough is provided, through which extends this wire, so that the middle part of the wire runs within the trough and can be tracked with appropriate lifting tools. In this way, a recessed arrangement of the lever ashes is ensured so that they do not protrude beyond the surface of the manhole cover, which reduces the burden of the lever ashes when passing, driving over o. The like. Of the manhole cover.

Advantageously, the lever ashtray can be anchored immovably in the filling, instead of being movably mounted between a rest position and a use position. The production of the manhole cover is simplified in this way and can be carried out more economically. Since it can be assumed that the manhole cover in most applications not daily or weekly, but at most several months or even several years away from the shaft, is associated with additional costs, the handling of the lever as possibly facilitating embodiment of Manhole cover in this majority of cases not economically useful. In view of the long intervals between use of the lever ashes, it is also questionable whether, if necessary, it can actually be moved without any problems or, if necessary, is difficult to navigate due to protection, corrosion and similar influences, in which cases the desired easier handling of the lever ashes would not have been realized.

Advantageously, it can be provided that the wire is not rectilinear but arcuate, wherein it has a curved upwardly extending middle part. In this way, the smallest possible depression of the trough in the filling as large a free space below the middle part of the lever ashes ensures, so that it can be easily detected - even if it is immovably anchored in the filling. A weakening in the filling, which can be effected by the trough and the correspondingly reduced material thickness of the filling, can be kept as low as possible by a flat design of the trough. In this way, a sufficiently stable manhole cover can be created with the least possible use of materials.

For economic reasons, it can be advantageously provided that the GRP material has no complicated longitudinal rovings, which have particularly good mechanical properties, but the GRP material may advantageously comprise non-directional fiber mats as reinforcing fibers, which are more economical to obtain than the aforementioned rovings. The achievable by the concrete filling properties of the manhole cover are sufficient anyway, so that the achievable by the soil strength and resilience improvement of the manhole cover ensures sufficient load capacity for the manhole cover even when using such non-directional fiber mats in the ground.

The concrete used as filling must be for the desired strength of the manhole cover no high performance or polymer concrete o. The like., So concrete with special aggregates, but the concrete may be designed for economic reasons as pure mineral concrete. The sufficient strength or load capacity of the manhole cover can be easily achieved even with such a simple designed concrete material, for example, if the additives used are assembled in a suitable manner, as is known in practice, for example by sand of a certain grain size is used, ie a certain so-called grading curve, so that by matching the individual, different sized aggregates in the concrete already sufficient strength values for the filling, and thus for the entire manhole cover are possible.

Fig. 1

eine perspektivische Ansicht auf einen Schachtdeckel,

Fig. 2

eine Ansicht ähnlich Fig. 1, jedoch mit einer teilweise durchsichtig dargestellten Füllung, und

Fig. 3

einen Querschnitt durch den Schachtdeckel der Fig. 1 und 2.

An embodiment of the invention will be explained in more detail below with reference to the purely schematic representations. It shows

Fig. 1

a perspective view of a manhole cover,

Fig. 2

a view similar Fig. 1 , but with a partially transparent filling shown, and

Fig. 3

a cross section through the manhole cover of Fig. 1 and 2 ,

In the drawings, 1 designates as a whole a manhole cover which essentially consists of concrete, the concrete forming a filling 2 which is poured into a plastic shell which forms a bottom 3 of the manhole cover 1. The bottom 3 is designed shell-shaped and forms not only the bottom, but also a circumferential side edge.

In the filling 2 two troughs 4 are provided, which are diametrically opposed to each other and through which extends a wire forming a lever ashtray 5.

In particular Fig. 2 shows, each wire is approximately wave-shaped and is anchored with its two ends in the filling 2, while the middle part of this wire extends upwards and through the trough 4. In this way, a comparatively small layer thickness of the filling 2 is achieved, since the two ends of the wire are covered by a comparatively thick layer of the filling 2 and thus have an excellent hold in the filling 2 against breakage, on the other hand, the middle part of each wire extends as Lever ashes 5 at a great distance higher than it corresponds to the deepest bottom of the trough 4, so that the lever ashes 5 can be easily understood and accordingly the manhole cover 1 can be handled easily.

For the production of a manhole cover 1, only three different components are used, namely, first, the bottom 3, in which then the filling 2 is filled, wherein a wire is poured as a lever ashtray 5 and enclosed by the filling 2. Of these three different components of the wire or the lever ashtray 5 is used in duplicate, but manufacturing technology to produce only three different components to create the manhole cover 1. The concrete of the filling 2 is a comparatively simple and inexpensive concrete material, as a purely mineral concrete without polymer additives o. The like. Does not have fiber reinforcements o. The like., So that he for the required strength of the manhole cover 1 a particularly economical production of Manhole cover allows.

Claims (7)

Manhole covers,
with a bowl-shaped bottom,
and with a filling of concrete arranged inside this cup-shaped bottom,
characterized in that The base (3) consists of a glass-fiber reinforced thermosetting plastic,
a rough inner side facing the filling (2) and a layer thickness of at most 5 mm, ■ the concrete forming the filling (2) is designed as purely mineral concrete, ■ between the bottom (3) and the filling (2) a bonding agent is provided, In the filling (2) one or more recessed lever levers (5) are provided,
wherein a lever tab (5) is formed of a wire whose two ends are anchored in the filling (2) and whose middle part extends through a depression (4) provided in the surface of the filling (2), ■ and that the manhole cover (1) is formed exclusively of the aforementioned elements. Manhole cover according to claim 1,
characterized,
in that two lever tabs (5) are provided, which lie opposite one another with respect to the center of the manhole cover (1). Manhole cover according to claim 1 or 2,
characterized,
that the wire forming a lever ashes (5) is curved,
wherein it has an upwardly curved middle part. Manhole cover according to one of the preceding claims,
characterized,
that the lever ashes (5) is anchored immovably in the filling. Manhole cover according to one of the preceding claims,
characterized,
that the plastic is reinforced with non-directional fiber mats. Manhole cover according to one of the preceding claims,
characterized,
that the manhole cover can be loaded up to a permissible weight load of 5 tons. Manhole cover according to one of the preceding claims,
characterized,
that the manhole cover can be loaded up to a bursting force of 6 t.

Images