EP3929360A1 - Shaft cover system, magnetic cover for such a shaft cover system and method for separating a cover layer from a shaft cover of a shaft cover system - Google Patents

Abstract

The invention relates to a manhole cover system (1), comprising: a manhole cover (10) and a magnet cover (20) for covering a side of the manhole cover (10) facing away from a manhole (30), the magnet cover (20) being designed in such a way that its The size essentially corresponds to the size of the side of the manhole cover (10) facing away from the manhole (30), and the magnetic cover (20) and the manhole cover (10) can be held in a fixed position in relation to one another by means of a magnetic force.

Description

The invention relates to a manhole cover system, a magnetic cover for such a manhole cover system and a method for separating a cover covering from a manhole cover of a manhole cover system.

When building roads, a manhole system is often installed in order to ensure the water drainage from the road as well as for control and maintenance work on pipes for dirty water and electricity lines such as telephone, internet, etc. The road construction usually takes place in two stages, namely a first stage in which the provisionally finished road is opened to traffic for a certain period of time. The surface of this first stage of the road is a few centimeters lower and coarser-grained (called HMT) than the road when the finished pavement is in place. In this provisional stage, however, the concrete manhole pipes are already fully assembled and with a concrete base in which the adjustable manhole, the so-called NIVO manhole cover ring plus cover was concreted in order to make height adjustments later. The manhole covers are also built at the first provisional height in this stage.

After a certain time, for example when the surface has settled due to the impact of vehicles, the definitive covering is then applied up to the intended height, this end covering (top covering) also completely covering all the manhole covers. Before being built over the shafts are partly sprayed with a separating solution or through so-called auxiliary covers, which have to be purchased, stored, cleaned every time and repeatedly (upon delivery and return) manually palletized to prevent the cover from sticking. In practice, however, this system only works to a limited extent, as the release agent is applied too early and thus evaporates again prematurely or is even forgotten, and cost-intensive cleaning has to be carried out. Another solution are adhesive foils, which are glued to the metal of the manhole cover. Depending on the surface of the metal shaft, different surface treatments are selected so that the sticky top layer can be removed again later. At a temperature of 170 ° C during the application of the top layer, however, the adhesive film and / or the adhesive can be melted or evaporated so that the top layer can still be in direct contact with the manhole cover at least in sections and can adhere to it. In the most frequent cases, the adhesive bonds with the manhole cover, and the final results are sometimes even more negative, as it is almost impossible to completely remove the adhesive film later when it cools down.

After the end layer or cover layer has been applied, the manhole cover must be pulled through the cover layer using a specially made hydraulic pulling system, after which the manhole ring in which the cover has rested is built up to the correct level and mortared. After that, the top covering must be removed from the manhole cover or sharpened by hand. However, some manhole covers not only have a simple smooth surface, but are also provided with names, coats of arms or other graphics in relief. As a result, the removal of the top covering is often extremely time-consuming. Through the manual sharpening, the the above graphics are damaged or even destroyed. This time-consuming work leads to enormous additional costs, which must be avoided. In the case of a longer, new stretch of road, the team's staff often spend most of their time cleaning the cover of the manhole cover, as the building owner's specifications have to be complied with.

In view of the above, the object of the present invention is to provide a manhole cover system, a magnetic cover for such a manhole cover system and a method for separating a cover from a manhole cover of a manhole cover system, whereby reworking for cleaning the manhole cover can be avoided or at least reduced.

The object is achieved by a manhole cover system, a magnetic cover for such a manhole cover system and a method for separating a cover covering from a manhole cover of a manhole cover system according to the independent claims. Advantageous developments of the invention are contained in the dependent claims.

According to the invention, a manhole cover system has a manhole cover and a magnet cover for covering a side of the manhole cover facing away from a manhole, the magnet cover being designed such that its size essentially corresponds to the size of the side of the manhole cover facing away from the manhole and wherein the magnet cover and the manhole cover over a magnetic force can be retained in a fixed position with respect to one another.

The magnetic cover, that is to say a cover that applies magnetic force, thus covers the manhole cover on the side of the cover layer application, so that the cover layer does not directly adjoin the side of the manhole cover facing away from the manhole can adhere. The fact that the size of the magnetic cover "essentially" corresponds to the size of the manhole cover is aimed at the fact that, particularly in road construction, comparatively large tolerances and manufacturer-specific sizes can occur. Even if a match of the sizes as precisely as possible is desirable in order to be able to bring the cover layer as close as possible to the manhole cover, but conversely to cover it as little as possible, certain deviations are tolerable in terms of manufacturing efficiency.

As a result of the magnetic force applied by the magnet cover, the magnet cover can be held on the shaft cover in a fixed position. For this purpose, the shaft cover itself is at least partially magnetic or can accommodate a magnetic adapter component by means of which the magnetic cover can be held in a fixed position relative to the shaft cover. Such an adapter component can be screwed into the manhole cover or inserted in some other form-fitting manner. In many cases, however, the manhole cover, as a cast cover, is already magnetic.

The magnet cover is configured in such a way that the magnetic force attracts the slot cover at least to achieve the positionally fixed relationship between the magnet cover and the slot cover. The magnetic force should be at least so great that lateral forces during the application of the cover layer do not lead to a relative displacement between the magnet cover and the shaft cover in the direction of the lateral forces.

According to the above, the magnet cover can be arranged in a simple manner on a manhole cover in order to prevent a cover layer from sticking to the manhole cover. In particular, the fixed-position relationship between the magnet cover and the shaft cover can be maintained even if the shaft cover is wet, oily or damaged.

In principle, the magnet cover can also be used several times. However, since the cover layer adhering to it can be disruptive or the magnet cover is no longer in its original state due to damage caused by a cover layer application or its removal, the magnet cover can also be used as a disposable item at comparatively low costs.

In one embodiment, the magnet cover has an engagement for lifting the magnet cover, at least on its side facing away from the shaft cover.

The engagement can be an undercut or also be formed via a through opening. The magnet cover can be lifted by the engagement itself. If the shaft cover is only to be lifted together with the magnet cover by engaging the magnet cover, the magnetic force acting between the magnet cover and the shaft cover is at least as great as the weight of the shaft cover. As an alternative or in addition, the engagement can also be designed in such a way that it can be used to engage in a shaft cover engagement, such as a central hole or a so-called Bickelloch, and thus the magnet cover is also raised by lifting the shaft cover. In this case the magnetic force does not have to hold the weight of the manhole cover, but can only be designed to maintain the fixed positional relationship during the application of the top covering. The magnetic force can also be less than the weight of the shaft cover in order to separate it from the shaft cover by lifting the magnet cover through the set ratio of forces.

According to a further development, the magnet cover and / or the shaft cover are / is designed, at least in sections, as an electromagnet.

The magnetic force can be switched on and off or its strength and / or direction can be varied by means of electromagnets. For example, the magnetic cover can be positioned on the shaft cover with little or no magnetic force and the magnetic force required to maintain the position can only be applied after the positioning has been completed. The separation of the magnetic cover from the shaft cover can also be supported by eliminating or reducing the magnetic force or by reversing the direction of force.

In a further aspect, the invention also relates to a magnet cover for a protruding manhole cover system, the magnet cover being designed at least in sections as a permanent magnet and / or electromagnet.

The term “in sections” can refer to an arrangement in a plane parallel to a side of the magnet cover facing the shaft cover as well as in a direction perpendicular to this plane. With a permanent magnet, the magnetic force can be provided in a simple and inexpensive form through the magnet cover. the In comparison to this, however, the electromagnet can provide a higher functionality according to the above explanations. A combination of permanent magnet and electromagnet also enables greater flexibility of use, although the magnet cover can be used by the permanent magnet regardless of the possibility of using the electromagnet.

In particular, the magnetic holding force that can be applied by the magnet cover is between 20 to 80 cN / cm ² , preferably between 40 and 70 cN / cm ² , particularly preferably between 50 and 57 cN / cm ² .

The details of the holding force relate to an air gap d = 0 mm and are defined as pull-off forces in cN / cm ² perpendicular to the contact surface.

If the magnetic force is too low, the maintenance of a fixed relationship between the magnet cover and the manhole cover during the application of the top layer and the associated external forces cannot be guaranteed. On the other hand, excessive magnetic forces can unnecessarily increase the effort required to separate the magnetic cover from the shaft cover.

In one embodiment, the magnetic cover comprises at least one magnetic film.

Magnetic foils can be cut to size in a simple manner and can also be easily combined with another carrier material. Both semi-anisotropic and anisotropic magnetic foils can be used.

Semi-anisotropic magnetic foils have the advantage that they Are PVC-coated (vulcanized) and are not glued to the magnetic foil, but welded.
But they have the disadvantage that they have a weaker adhesive force than anisotropic magnetic foils.

Anisotropic magnetic foils have the advantage that they are not coated and can be glued to various foreign carriers.
However, they have the disadvantage that they are more sensitive to kinking in the raw state.

The thickness of the magnetic film is preferably greater than or equal to 0.5 mm. More preferably, the thickness of the magnetic film is less than or equal to 1 mm. In particular, the thickness of the magnetic film is approximately 0.75 mm.

Magnetic foils with a thickness of 0.5 mm to 1.5 mm can already provide sufficient magnetic force and can nevertheless also be used for disposable items in terms of the costs involved and their processability. In addition, the overall height of the magnet cover can be kept comparatively low. Accordingly, it is possible to make the magnet cover elastic to such an extent that the magnet cover does not have to be separated from the shaft cover over its entire surface, but can be peeled off, that is to say can be separated step by step.

According to one embodiment, the magnetic film has a remanent flux density B _R of 150 to 200 mT, in particular 170 to 180 mT.

For example, a magnetic film with a thickness of 0.75 mm with a remanent flux density B _R of 179 mT can be used.

In particular, the coercive field strength of the magnetic film is in the range from 100 to 110 kA / m, in particular around 103 kA / m.

According to a development, the magnet cover comprises at least one protective film.

The protective film can have one or more layers. The film is preferably resistant to chemicals. The thickness can, for example, be in the range 0.3 to 0.4 mm to achieve a comparatively thin magnet cover.

In particular, the protective film is a self-adhesive plastic film, the protective film being connected to the magnetic film via an adhesive film formed by the plastic film.

The magnetic film and protective film can thus be connected in a simple manner. Alternatively, the magnetic film can also be connected to protective film using other application methods.

In one embodiment, the protective film is printable, in particular UV printable.

The magnetic cover can thus be provided directly with handling instructions or advertising content. For this purpose, the protective film is arranged, for example, on the side of the magnet cover facing away from the shaft cover, so that the imprint on the protective film is still recognizable when the magnet cover has been positioned on the shaft cover. Irrespective of an imprint, such an arrangement of the protective film can be advantageous in order to protect the magnetic film after it has been positioned on the shaft cover up to To protect the top coat application.

In particular, at least the magnetic film and / or the protective film are / is particularly preferred in a temperature range from -20 ° C to + 100 ° C, in particular from -15 ° C to + 80 ° C, in particular also briefly up to 180 ° C Can be used up to 200 ° C.

The magnetic film and / or the protective film can thus be used under normal ambient conditions. Even when the top layer is applied at around 170 ° C., at least short-term heat resistance can be sufficient to avoid the magnetic foil and / or the protective foil from being significantly damaged. If the protective film can adequately protect the magnetic film, it may be sufficient to make only the former appropriately heat-resistant. Due to the heat resistance of the magnetic foil and / or protective foil, the hot cover layer cannot penetrate to the shaft cover.

In one embodiment, at least one side of the magnet cover facing outward in the manhole cover system is designed to be slip-resistant, at least in sections.

The outwardly facing side of the magnet cover is in particular the side of the magnet cover which, when the magnet cover is positioned on the shaft cover, is on the side of the magnet cover facing away from the shaft cover. This can prevent pedestrians or vehicles from slipping on the magnetic cover before the final top covering is applied. As an alternative or in addition, such a coating can also be on the side of the magnet cover facing the shaft cover be provided in order to additionally secure the holding of the magnet cover in a fixed position relation to the shaft cover against lateral forces. The slip resistance can be achieved by selecting the appropriate material and / or surface structuring. The outwardly facing side of the magnetic cover can be formed, for example, over the magnetic film or protective film.

• Anordnung des Schachtabdeckungssystems auf einem Schacht, wobei die Schachtabdeckung dem Schacht zugewandt und die Magnetabdeckung dem Schacht abgewandt ist,
• Auftrag des Deckbelags, wobei zumindest ein Teil der Magnetabdeckung des Schachtabdeckungssystems vom Deckbelag überdeckt wird,
• Anheben der Magnetabdeckung, und
• Aufhebung und/oder Überwindung der Haltekraft der Magnetabdeckung zum Lösen der Schachtabdeckung von der Magnetabdeckung.

In a further aspect, the invention also relates to a method for separating a cover covering from a manhole cover of a preceding manhole cover system, comprising the steps:

• Arrangement of the shaft cover system on a shaft, with the shaft cover facing the shaft and the magnetic cover facing away from the shaft,
• Application of the cover layer, whereby at least part of the magnetic cover of the manhole cover system is covered by the cover layer,
• Lifting the magnet cover, and
• Removal and / or overcoming of the holding force of the magnet cover to detach the shaft cover from the magnet cover.

The manhole cover and the magnetic cover as components of the manhole cover system do not have to be placed on the manhole and therefore preassembled at the same time. First of all, only the manhole cover can be placed on the manhole, while the magnetic cover must be provided at the latest when the top covering is applied. The magnetic force then holds the magnetic cover in a fixed position with respect to the shaft cover during the application. If the magnet cover includes electromagnets for such a magnetic force, these must then be activated accordingly.

A hydraulic pulling system or other tool can be used to lift the magnet cover. The magnetic cover is pulled through the cover, which sticks to it. The lifting can go hand in hand with the detachment of the magnet cover from the manhole cover. In this case, the magnetic force is less than the weight of the shaft cover, or the shaft cover is otherwise held on the shaft, and the tensile force on the magnet cover is greater than the holding force caused by the magnet between the magnet cover and the shaft cover. Corresponding force ratios can be controlled or varied accordingly by using electromagnets in the magnet cover. By switching off an electromagnet, its magnetic force can also be completely canceled. However, the magnet cover can also only be separated from the shaft cover after it has been lifted or removed from the shaft. Here, the magnetic cover can, for example, apply a magnetic force at least during lifting or removal, which is at least greater than the weight of the shaft cover. A later separation or loosening can then take place by reducing the magnetic force in the case of electromagnets or by overcoming tensile forces.

• Figur 1 zeigt eine schematische Querschnittsansicht eines Schachtabdeckungssystems gemäss einer exemplarischen Ausführungsform der Erfindung.
• Figur 1 zeigt eine schematische Querschnittsansicht eines

In the following, the invention is explained in more detail on the basis of an embodiment with reference to the attached figure. The figure shows in detail:

• Figure 1 shows a schematic cross-sectional view of a manhole cover system according to an exemplary embodiment of the invention.
• Figure 1 shows a schematic cross-sectional view of a

Manhole cover system 1 according to an exemplary embodiment of the invention. The shaft cover system 1 covers a shaft 30 and comprises a shaft cover 10 and a magnetic cover 20. The shaft cover 10 is placed on the shaft 30 and the magnetic cover 20 is in turn placed on the shaft cover 10. To protect the manhole cover 10 when a cover layer is applied, the magnet cover 20 is positioned on the manhole cover 10 in such a way that it covers it with an accurate fit. The shaft cover 10 and the magnet cover 20 thus have essentially the same shape in a plane parallel to the side of the shaft cover 10 facing the shaft. In order to be able to lift the magnet cover 20, the magnet cover 20 has an engagement 21. This is designed here, for example, as a through opening, with a corresponding lifting device being able to pass through the through opening as engagement 21 of the magnet cover 20 and through a shaft cover engagement 11 of the shaft cover 10, which is also designed as a through opening. The engagement 21 of the magnet cover 20 can, however, also be configured in such a way that a lifting tool only engages the magnet cover 20.

In the embodiment shown, the magnetic cover is formed from a magnetic film 22 and a protective film 23. The magnetic film 22 and the protective film 23 can be made of one or more layers. A plurality of magnetic foils 22 and protective foils 23 can also be arranged one behind the other or alternately. In Figure 1 the magnetic film 22 is arranged on the side of the magnetic cover 20 facing the shaft cover 10. As a result, the magnetic force applied by the magnetic film 22 can act directly on the shaft cover 10 without the holding force resulting from a further spacing or material shielding is reduced. The protective film 23 is arranged on the side of the magnet cover 20 facing away from the shaft cover 10. This is chemical and heat resistant, so that the underlying magnetic film 22 is not damaged when a top layer is applied. In the same way, the magnetic film 22 itself can also be resistant to chemicals and heat, in order for its part to protect the shaft cover 10 and to avoid material adhesion. The protective film 23 is also designed to be slip-resistant and can therefore not only serve to protect the magnetic film 22, but also reduce the risk of accidents for passers-by and / or vehicles crossing the shaft cover system 1.

A magnetic film 23 with a thickness of 0.75 mm can be used as a magnetic cover 20, for example, as a disposable product, the magnetic cover made of magnetic film 22 and protective film 23 having a thickness of up to 1.1 mm. The protective film 23 consists of a PVC-welded self-adhesive film with UV printing for manufacturer information or with handling instructions.

The magnetic foils have dimensions of 0.5 - 1.5mm, and the diameter of the buggy holes can vary.

With a material thickness of 0.75 mm, the magnetic foil 23 as a semi-anisotropic magnetic foil, for example, has a holding force of 50 cN / cm ² and the magnetic foil 23, as an anisotropic magnetic foil, has, for example, a holding force of 57 cN / cm ² . The details of the holding force relate to an air gap d = 0 mm and are defined as pull-off forces in cN / cm ² perpendicular to the contact surface.

The magnetic film 23 has a remanent flux density B _R of 179 mT, a coercive field strength BHc of 103 kA / m, a maximum Energy product BH of 5.49 kJ / m ³ or 0.96 MGOe, a density of 3.6 g / m ³ and a Shore D hardness of 55. The maximum temperature range is -15 ° C to + 80 ° C, briefly up to 180 ° C / 220 ° C. The pole spacings are 2.1 mm and the magnetic film 23 is multi-pole both on one and two sides and coated with protective lacquer on the magnetic side.

The magnetic film 23 is composed of approx. 89% barium ferrite or strontium ferrite, approx. 9.5% plastic elastomers, here without PVC, and otherwise of 1.5% binders and plasticizers.

The invention is not restricted to the embodiment described. The invention, which can have square or rectangular shapes, can also be used to protect the inlet / drainage shafts.

List of reference symbols

1

Manhole cover system

10

Manhole cover

11th

Manhole cover engagement

20th

Magnetic cover

21

Engagement (magnetic cover)

22nd

Magnetic foil

23

Protective film

30th

Manhole

Claims (15)

Manhole cover system (1), comprising: a manhole cover (10) and a magnet cover (20) for covering a side of the shaft cover (10) facing away from a shaft (30), wherein the magnet cover (20) is designed in such a way that its size essentially corresponds to the size of the side of the shaft cover (10) facing away from the shaft (30) and wherein the magnetic cover (20) and the shaft cover (10) can be held in a fixed position with respect to one another by means of a magnetic force. Manhole cover system (1) according to Claim 1, the magnet cover (20) having an engagement (21) for lifting the magnet cover (20) at least on its side facing away from the manhole cover (10). Manhole cover system (1) according to Claim 1 or 2, the magnet cover (20) and / or the manhole cover (10) being designed at least in sections as an electromagnet. Magnetic cover (20) for a manhole cover system (1) according to one of Claims 1 to 3, the magnetic cover (20) being designed at least in sections as a permanent magnet and / or electromagnet. Magnet cover (20) according to claim 4, wherein the magnetic holding force that can be applied by the magnet cover (20) is between 20 to 80 cN / cm ² , preferably between 40 and 70 cN / cm ² , particularly preferably between 50 and 57 cN / cm ² located. Magnetic cover (20) according to Claim 4 or 5, the magnetic cover (20) comprising at least one magnetic film (22). Magnetic cover according to Claim 6, the magnetic film having a thickness of 0.5 mm to 1.5 mm, in particular approximately 0.75 mm. Magnetic cover (20) according to Claim 6 or 7, the magnetic film (22) having a remanent flux density B _R of 150 to 200 mT, in particular 170 to 180 mT. Magnetic cover (20) according to one of Claims 6 to 8, the coercive field strength of the magnetic film (22) being in the range from 100 to 110 kA / m, in particular approximately 103 kA / m. Magnetic cover (20) according to one of Claims 6 to 9, the magnetic cover (20) comprising at least one protective film (23). Magnetic cover (20) according to Claim 10, the protective film (23) being a self-adhesive plastic film, the protective film (23) being connected to the magnetic film (22) via an adhesive film formed by the plastic film. Magnetic cover (20) according to Claim 10 or 11, the protective film (23) being printable, in particular UV-printable. Magnetic cover (20) according to one of Claims 6 to 12, at least the magnetic film (22) and / or the protective film (23) in a temperature range from -20 ° C to + 100 ° C, in particular from -15 ° C to + 80 ° C, in particular also briefly up to 180 ° C , particularly preferably up to 200 ° C, can be used. Magnet cover (20) according to one of Claims 4 to 13, at least one side of the magnet cover (20) facing outward in the shaft cover system (1) being at least partially non-slip. Method for separating a cover covering from a manhole cover (10) of a manhole cover system (1) according to one of claims 1 to 3, comprising the steps: - Arrangement of the shaft cover system (1) on a shaft (30), the shaft cover (10) facing the shaft (30) and the magnetic cover (20) facing away from the shaft (30), - Application of the cover layer, with at least part of the magnetic cover (20) of the manhole cover system (1) being covered by the cover layer, - Lifting the magnet cover (20), and - Abolition and / or overcoming of the holding force of the magnet cover (20) for releasing the shaft cover (10) from the magnet cover (20).

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