WO1998040571A1

WO1998040571A1 - Shaft cover

Info

Publication number: WO1998040571A1
Application number: PCT/AT1998/000051
Authority: WO
Inventors: Gerhard Fleischhacker
Original assignee: Gerhard Fleischhacker
Priority date: 1997-03-10
Filing date: 1998-03-04
Publication date: 1998-09-17
Also published as: JP2001514715A; EP0966576B1; DE59805800D1; CA2283796A1; EP0966576A1; AT404609B; AU6283898A; ATE225443T1; ATA40497A

Abstract

The invention relates to a shaft cover (1) having openings (2) through which a fluid medium is able to pass. Each of these openings (2) is fitted with at least one filter element (3) and the space left between the outer surface of the filter element (3) and the inner wall of the opening (2) is filled with an elastic material (4).

Description

Manhole cover

The present invention relates to a manhole cover which is provided with openings for the fluid medium passage, a filter element for the construction of this manhole cover, a method for improving the filtering effect of such manhole covers, and a shaping stamp for use in this method.

The problem with shaft covers is that - with the exception of larger stones or the like, which cannot pass through the openings in the shaft cover - any contaminants contained in the waste water, such as dirt, sand, oil contamination, etc., enter the shaft unhindered, e.g. a district heating shaft, and can lead to deposits on the shaft floor, in the district heating pipe system or to environmental pollution.

A solution to this problem is known from AT U 1293 by the same applicant. In the known construction, a large-area filter element is arranged on the underside of the manhole cover, which extends into the openings with projections. The filter element is made in one piece from asphalt mixtures, plastics, etc.

The present invention aims to further improve the resistance to vibration and the self-cleaning ability of the known construction. This aim is achieved according to the invention in that at least one individual filter element is inserted into each of the openings of the shaft cover, the space remaining between the outer surface of the filter element and the inner wall of the opening being filled with an elastic material.

By using discrete filter elements, which are elastically anchored in the openings, excellent resistance to deformation, shocks or the like is. achieved. In addition, the vibrations and shocks induced when driving, for example Manhole cover a mechanical detachment of any sand or dirt particles stuck in the filter elements and their discharge downwards, which significantly increases the self-cleaning ability of the filtering manhole cover. Finally, the filter elements used also create a defined surface of the manhole cover.

The elastic material is preferably an elastomer, preferably a wear-resistant rubber mixture, which increases the abrasion resistance of the manhole cover.

A preferred embodiment of the invention is characterized in that the free flow cross section of the filter element increases from top to bottom. This special design of the filter elements means that solids contained in the wastewater can only penetrate up to a certain grain size; However, once they have penetrated, they do not move the filter elements due to the increase in the free flow cross-section, but are discharged.

As described in AT U 1293, the filter element can, for example, be made from several layers of porous material or with channels with small diameters, the flow cross-section of the free layers increasing from layer to layer. However, the filter element preferably has a base body made of water-impermeable material, in which channels for the fluid medium passage are formed, the flow cross-section of which increases at least in steps, particularly preferably continuously, from top to bottom, which further improves the self-cleaning effect.

In any case, it is particularly advantageous if, according to a further feature of the invention, the filter element is provided on its outer circumference with ribs and / or grooves for anchoring in the potting material.

It is also particularly advantageous if the elastic material forms a layer covering the underside of the shaft cover between the filter elements. The layer is preferred additionally with the help of screws, rivets or the like. anchored to the underside of the manhole cover.

All of these measures are suitable

to avoid an increased yield of dirt in the shaft,

to ensure adequate ventilation of the shaft,

to allow any steam to escape from the shaft,

not to reduce the required strength of the manhole cover,

not to affect the service life of the cast construction,

improve the vibration resistance, and / or

not to impair the strength and intended load capacity of the cover.

Another aspect of the invention consists in the creation of a filter element specifically designed for the construction of such a manhole cover, which is characterized by a base body made of water-impermeable material, in which channels for the fluid medium passage are formed, the flow cross section of which is at least step-wise, preferably continuously, from top to bottom increases.

In a particularly advantageous embodiment, the filter element has a large-diameter throughflow section and an attachment plate placed thereon, which is pierced by openings opening into the throughflow section. This creates a step-like expansion of the flow cross-section from the front plate to the flow section. In addition, the openings can preferably widen at least in steps, preferably continuously, from top to bottom. It is particularly advantageous for the flow behavior if the inlet cross section of the openings in relation to the thickness of the facing plate is in the range from 1: 1 to 1: 4.

The throughflow section and / or the attachment plate are preferably made of metal or plastic, preferably steel. These materials result in a particularly robust filter element.

A third aspect of the present invention resides in the creation of a method for improving the filter effect of already existing manhole covers provided with openings for the fluid medium passage, and is characterized in that shaped punches are inserted into the openings, which have a base body, from the top of which form fingers protrude , the summed cross-sectional area of which is substantially smaller than the cross-sectional area of the base body, that the space remaining between the outer surface of the die and the inner wall of the opening is poured out with a sealing compound, which in the solidified state gives an elastic material, and that the die is then poured downwards the solidified potting compound can be removed.

With this method, elastically limited, downwardly widening openings are created in the manhole cover, and the stamps can be reused after the openings have been made. The elastic side walls of the openings increase their self-cleaning ability in the event of vibrations or the like. Since no special filter elements remain in the casting compound in this variant of the invention, there is a further cost saving.

A last aspect of the invention is concerned with the creation of a special form stamp for use in this method, which is characterized by a base body, from the top of which form fingers protrude, the summed cross-sectional area of which is significantly smaller than the cross-sectional area of the base body.

The shape fingers are preferred at least from bottom to top stepped, particularly preferably rounded or tapered, which leaves corresponding openings in the elastic material.

An advantageous embodiment of the die is characterized in that it is equipped on its underside with a coupling device for engaging a drawing tool, the coupling device preferably being a threaded bore. This also means that greater adhesive forces can be overcome when removing the stamp from the elastic material.

The invention is explained in more detail below on the basis of exemplary embodiments illustrated in the drawings.

The drawings show:

Fig.l a manhole cover in plan view,

2 and 3 a first embodiment of a filter element embedded in a manhole cover opening in plan view or in section,

4 and 5 a second embodiment in the same representation,

6 and 9 a first embodiment of a die inserted into a manhole cover opening during the implementation of the method according to the invention in plan view or in section,

7 and 8 a further possible embodiment of the die in section or in bottom view,

the Fig.10-12 side views of other embodiments of the form stamp, and

Fig.13 the form stamp of Fig.10-12 in plan view.

In Fig.l a manhole cover 1 made of cast iron is shown, which is provided with openings 2 for the passage of liquids or the escape of gases. One of the openings 2 is shown enlarged in FIGS. 2-7. In practice, the openings have a large diameter of, for example, 20-40 mm and can be round, square, oval or any shape. The cross section of the openings 2 can taper in the downward direction (FIG. 3), expand (FIG. 5) or run as desired.

A filter element 3 is inserted into each of the openings 2 of the manhole cover 1 with the interposition of an elastic material 4. The material 4 either ends flush with the top and bottom of the manhole cover 1 (FIG. 3) or covers the underside of the manhole cover as a layer 4 between the filter elements 3 (FIG. 5), with optional screws 5, rivets, Cast noses or the like. Can also be attached to the underside of the manhole cover 1.

The filter element 3 is positively embedded in the material 4 and can or the like on its outer circumference with grooves 6, ribs. be provided to improve the positive connection with the material 4.

The elastic material 4 is preferably a potting material that is elastic in its "solidified" state, for example wear-resistant rubber, elastic plastic or any elastomer.

The filter element 3 can have any structure as long as its flow cross-section increases in the flow direction, as described for example in AT U 1293. In the embodiments shown in FIGS. 2-5, the filter element 3 is composed of a tubular, large-diameter throughflow section 7 and an attachment plate 8 placed thereon, which is pierced by openings 9 opening into the inside of the throughflow section 7. The flow cross-section of the openings 9 in turn widens conically from top to bottom. The openings 9 can be arranged in any pattern, for example as shown in FIGS. 2 and 4. The diameter of the openings is preferably 1 to 7 mm (depending on the application, but also larger) on its entry side. The ratio of the diameter of the openings 9 to the thickness of the facing plate is preferably in the range from 1: 1 to 1: 4.

Both the throughflow section 7 and the attachment plate 8 are made of hard material, for example the throughflow section made of metal or plastic and the attachment plate made of steel. A one-piece production of throughflow section 7 and attachment plate 8 is also possible. In addition, cross-sectional cross-sectional expansions other than those mentioned are also possible, for example the openings 9 and the through-flow section 7 can be widened in a step-like manner and in the downward direction.

FIGS. 6-13 show an alternative method for improving the filtering effect of conventional manhole covers 1, wherein stamps 10 are inserted into each of the openings 2 before or during the casting of the elastic material. The form stamps 10 can, for example, be mounted on a common carrier plate (not shown), or can also be used individually.

Each form stamp 10 is composed of a base body 11 and projecting form fingers 12 thereof, the summed cross-sectional area of all form fingers 12 being smaller than the cross-sectional area of the base body 11, so that after removal of the form stamp 10 from the solidified casting compound, passage openings in the elastic material formed 4 result, the flow cross section increases from top to bottom. The cross section of the base body 11 and the shaped fingers 12 is arbitrary, for example round, oval, angular, etc. The passage openings remaining in the sealing compound can in particular have the cross-sectional configurations mentioned above in connection with the filter element 3.

If individual form stamps 10 are used, these can be used on their underside with a coupling device, such as a threaded bore 13, for the attack of a special tool Pulling out the die 10 can be provided from the solidified sealing compound 4.

The invention is of course not limited to the exemplary embodiments shown. For example, the number, size and grouping of the openings 9 in the filter element 3 or the shaping fingers 12 of the shaping punch 10 are completely arbitrary, as long as the flow cross-sectional relationships mentioned result.

Claims

claims

1. manhole cover, which is provided with openings for the fluid medium passage, characterized in that in each of the openings (2) at least a single filter element (3) is used, the between the outer surface of the filter element (3) and the inner wall of the Opening (2) remaining space is filled with an elastic material (4).

2. Manhole cover according to claim 1, characterized in that the elastic material (4) is an elastomer, preferably a wear-resistant rubber mixture.

3. manhole cover according to claim 1 or 2, characterized in that the free flow cross section of the filter element (3) increases from top to bottom.

4. Manhole cover according to one of claims 1 to 3, characterized in that the filter element (3) has a base body made of water-impermeable material, in which channels (9) are formed for the fluid medium passage, the flow cross-section at least step-wise, preferably continuously, from top to bottom increases below.

5. Manhole cover according to one of claims 1 to 4, characterized in that the filter element (3) is provided on its outer circumference with ribs and / or grooves (6) for anchoring in the elastic material (4).

6. Manhole cover according to one of claims 1 to 5, characterized in that the elastic material (4) forms a layer (4 ') covering the underside of the manhole cover (1) between the filter elements (3).

7. manhole cover according to claim 6, characterized in that the layer (4 ¹ ) additionally with the aid of screws (5), rivets or the like. anchored to the underside of the manhole cover is.

8. Filter element for a manhole cover according to one of claims 1 to 7, characterized by a base body made of water-impermeable material, in which channels (9) are formed for the fluid medium passage, the flow cross section of which increases at least in steps, preferably continuously, from top to bottom.

9. Filter element according to claim 8, characterized by a large-diameter throughflow section (7) and an attachment plate (8) placed thereon, which is pierced by openings (9) opening into the throughflow section (7).

10. Filter element according to claim 9, characterized in that the openings (9) expand at least step-wise, preferably continuously, from top to bottom.

11. Filter element according to claim 9 or 10, characterized in that the inlet cross section of the openings (9) in relation to the thickness of the facing plate (8) is in the range of 1: 1 to 1: 4.

12. Filter element according to one of claims 8 to 11, characterized in that it is provided on its outer circumference with ribs and / or grooves (6) for anchoring in the potting material (4).

13. Filter element according to one of claims 8 to 12, characterized in that the throughflow section (7) is made of metal or plastic.

14. Filter element according to one of claims 8 to 13, characterized in that the attachment plate (8) is made of metal or plastic, preferably made of steel.

15. A method for improving the filter effect of a manhole cover provided with openings for the passage of the fluid medium, characterized in that shaping stamps (10) are used in the openings (2), which have a base body (11), from the top of which form fingers (12) project, the summed cross-sectional area of which is considerably smaller than the cross-sectional area of the base body (11), that between the outer surface of the die (10) and the inner wall of the opening ( 2) remaining space is poured out with a casting compound which results in an elastic material (4) in the solidified state, and that the shaping stamps (10) are then removed in the downward direction from the solidified casting compound (4).

16. Form stamp for a method according to claim 15, characterized by a base body (11), from the top of which form fingers (12) protrude, the summed cross-sectional area of which is substantially smaller than the cross-sectional area of the base body (11).

17. Form stamp according to claim 16, characterized in that the shaping fingers (12) are tapered at least step-like from bottom to top.

18. Form stamp according to claim 16 or 17, characterized in that the shaping fingers (12) are rounded from bottom to top or are conically tapered.

19. Form stamp according to one of claims 16 to 18, characterized in that it is equipped on its underside with a coupling device (13) for attacking a drawing tool.

20. Form stamp according to claim 19, characterized in that the coupling device (13) is a threaded bore.