EP2857589A1 - Bursting protection systems for shaft covers - Google Patents

Abstract

The invention relates to a manhole cover with a lid (11) and a frame, wherein the lid (11) can be applied watertight to the frame. In order to eliminate the risk of explosions due to high pressure rise of the trapped air in the duct system even in heavy rainfall and large water increase in the duct system, the manhole cover (9) on a pressure relief device (16).

Description

The invention relates to a manhole cover or a corresponding attachment, which has a lid and a frame, wherein the lid can be applied watertight to the frame.

Manhole covers usually comprise a lid and a frame, on which the lid rests in the closed state with at least one, formed on its underside contact surface. The lid is usually closed-shaped and cooperates with the frames to provide a watertight and odor-tight seal.

The lids are usually made of cast iron, which allows a relatively inexpensive production and at the same time is sufficiently robust. The lids thus also withstand greater pressure loads, such as those caused by moving vehicles, stood without any problems. In addition, the use of cast iron leads to a relative high dead weight, which leads to a dense system on the frame and thus facilitates a gas-tight design.

Gas-tight manhole covers are used, for example, in surface water-carrying duct systems. In heavy rains such channel systems are filled relatively quickly with water, wherein the air contained in the channel system is compressed and collects in raised areas of the channel system. Such sites are, for example, manhole shafts, which are usually closed day-waterproof and odor-tight.

This can lead to a relatively high pressure load of the manhole covers used. Due to the physical laws, the pressure of the air doubles when the available volume is halved. An increase in water in the duct system, which, for example, halves the space available in the duct, thus doubles the pressure of the air in the duct system to approximately 2 bar. If the available volume is reduced by a quarter, the pressure is doubled again to approx 4 bar. After a further reduction in volume by one-eighth, the pressure is already at 16 bar. The pressure of the trapped air in the duct system increases exponentially and is well above the possible hydrostatic pressure of the water.

The high pressure leads to a high risk of explosion. As soon as the load capacity limit of the shaft head and / or the shaft cover or the cover is exceeded, sudden, strong outbreaks can occur. In this case, not only the shaft head, but also its surroundings such as a road surface is destroyed over a large area as a rule.

Existing systems for pressure relief often react too slowly or too slowly and can be retrofitted into existing systems only with great effort. This is particularly important because heavy rainfall events occur more frequently and thus also existing plants are affected even in shallow areas with a slight slope in the sewer system.

The invention is therefore based on the object to provide a manhole cover, which eliminates the disadvantages of the prior art and in particular allows a sufficiently fast-acting pressure relief of the channel system. In addition, this manhole cover can be retrofitted in existing systems without much effort.

Main features of the invention are specified in claim 1. Embodiments are the subject of the dependent claims.

In a manhole cover with a lid and a frame, wherein the lid can be applied watertight to the frame, it is provided according to the invention that the manhole cover has a pressure relief device.

It is therefore not in addition to the manhole cover provided a pressure relief, but integrated the pressure relief device in the manhole cover. Retrofitting existing systems can then be done by simply replacing the old manhole cover by a manhole cover according to the invention. The pressure relief then takes place, for example, at the highest point and is correspondingly effective. In this case, the pressure relief device opens only after exceeding a certain differential pressure, so that it is normally watertight and odor-tight in the normal case and at pressure from above.

In a preferred embodiment, the lid has at least one opening in which the pressure relief device is arranged. The frame can be designed as usual. Retrofitting can then optionally be done by simply replacing the lid. Since the pressure relief device is arranged in an opening of the lid, the surface can be kept relatively low, so that even loads on the pressure relief device are kept low, for example by moving over the lid vehicles. In addition, the overall stability of the lid is only slightly affected.

In this case, the opening can be arranged centrally in the lid. Alternatively or additionally, the cover may have a plurality of apertures, which are in particular arranged symmetrically and optionally on a circular line. The number and size of the openings depends, for example, with the theoretically expected pressure surges, which in turn depend on the design and size of the shafts or the channel system.

In order to achieve sufficient stability, in particular radially extending ribs may be formed on an underside of the lid. These ribs can emanate in particular from a centrally formed on the bottom wall. The apertures may then be formed between the ribs so that the areas adjacent to the apertures are reinforced by the ribs.

In a centrally formed in the lid opening, it is advantageous if the wall surrounds them coaxially. The wall then ensures in the area of the opening for a high stability of the lid.

If at least one recessed grip is formed on the upper side or, in particular, two diametrally opposite gripping recesses are provided, the cover can be grasped relatively easily with a tool and the shaft cover can be opened. Also, the top of the lid may be textured to achieve high slip resistance

In a particularly preferred embodiment, the pressure relief device is designed as a cap whose outline is adapted to the shape of the opening and which is tightly inserted into the opening. The cap is held in the opening in such a way that an upper side of the cap is substantially flush with the upper side of the lid. The opening may in particular have a circular shape, wherein the cap also has a round shape. This makes a tight connection relatively easy to implement. The cap can be frictionally or non-positively held in the opening, in addition, a surmountable positive connection can be provided.

In a preferred embodiment, the opening has inclined side edges, the cap being correspondingly conical at its edges. As a result, on the one hand, manufacturing tolerances can be compensated for and on the other hand it is prevented that the cap is pressed through the opening when pressure is applied from above. Also prevent the inclined side edges jamming and allow for a compression of the cap in the opening a relatively simple ejection, as soon as a corresponding shaft-side pressure occurs. The cap can be kept in the desired position in the opening due to the inclined side edges, without a mechanical stop is required. Due to the simultaneous conical configuration of the edges of the cap, a relatively large surface contact is obtained, with the requirements of Tragwasserdichtigkeit and odor-tightness can be safely met.

Preferably, the cap has a base, from the inside of a circumferential, in particular cylindrical wall emanates. On the one hand, this wall increases the stability of the cap and, on the other hand, facilitates insertion of the cap into the opening.

It can be provided that between the wall and side edges of the opening at least one contact point is formed. The cap is thus not only with its conical edges, but also with the wall at the side edges of the opening. This results in a good frictional and possibly non-positive retention of the cap in the opening.

Preferably, at least one outwardly projecting escapement is arranged on the wall, which is designed in particular as a circumferential bead. This inhibition is located in particular at a distance from the underside of the cap or the base surface, which corresponds to a thickness of the lid, so that the escapement is arranged on the underside of the lid. The cap is then additionally held in a form-fitting manner in the opening, wherein the escapement, however, is sufficiently easily deformable in order to be able to press the cap out of the opening when a correspondingly large shaft-side pressure occurs. Removal of the cap, for example, by a third party from the top of the lid is prevented by the inhibition but at least difficult.

Preferably, the cap has a plastic material. The cap is thus inexpensive to produce as an injection molded part. In addition, a plastic material corrosion resistant and has a relatively low density. Accordingly, a weight of the cap can be kept low, allowing a quick response to pressure surges due to low inertia. In addition, a risk of injury due to a flying cap is kept low.

In a further preferred embodiment, the cap is designed as a spring-loaded closure for the opening. The cap can then not completely remove from the lid when an increased pressure in the channel system occurs and therefore does not need to be replaced after the response. By the spring load a secure positioning of the cap is obtained in the opening, wherein the cap is loaded in the closing direction. This ensures good tightness. In addition, can be adjusted by the spring load relatively easy, from which pressure difference to open the pressure relief device. In this embodiment, the cap is formed in particular of metal or cast iron

It is particularly preferred that the cap has on an inner side at least one pin, which is guided by a arranged on the underside of the lid cage, wherein the pin is arranged in particular centrally on the cap. The cap is then guided by means of the pin linearly relative to the lid, wherein the shaft-side pressure can act through the cage on the underside of the cap and thus loaded in the opening direction. The pin extends in particular perpendicular to the cover and axially to the opening, so that the cap can be pressed out without tilting out of the opening.

Preferably, the pin has a particular adjustable via a threaded mating stop, wherein a spring element between the stop and cage is clamped. With an adjustable stop, which is formed in the simplest case as a threaded nut, the bias of the spring element and thus the pressure required to open the cap can be adjusted relatively easily. In this case, the spring element is in particular designed as a helical compression spring, through which the pin is guided. This results in a symmetrical introduction of force and a particularly space-saving arrangement.

On the inside of the cap, a thickening formed in particular of plastic can be formed. This thickening can strengthen the connection between the pin and cap and possibly cause a larger contact area with the side edges of the opening and thus increase the tightness.

A simple positioning of the cap in the opening is achieved in that the cap rests on at least one protruding into the opening projection, wherein the projection is in particular formed circumferentially. The cap is then pulled by the spring element against the projection and held in a defined axial position.

Preferably, locking latches for fastening the lid to the frame are arranged on the underside of the lid. The frame then advantageously has recesses for the locking latch, wherein the locking latch and the recesses in particular form a bayonet closure. With the help of the locking latch, the lid can then be connected watertight and odor-tight with the frame. Optionally, the lid can be pulled through the locking bolt in the direction of the frame to rest without play on the frame and to increase the tightness.

In a preferred embodiment, the cover is movably connected to the locking latch, wherein the locking latch are loaded by spring elements in the direction of the lid. The entire lid can then be lifted from the frame at a sufficiently high shaft-side overpressure, so that the pressure can escape. About the spring elements can then adjust the amount of pressure relatively easy. In addition, the lid is pulled by the spring elements in the direction of the frame and thus ensures a tight seal between the frame and lid normally. The spring elements act in particular perpendicular to the extension of the lid.

In a preferred embodiment, pins fixedly connected to the cover are guided through the locking bolt, wherein the pins have a particularly adjustable stop and a spring element is clamped between locking bolt and stop. The pins, which extend in particular perpendicular to the lid, then cause a linear guide of the lid and prevent tilting of the lid when it is opened by shaft-side overpressure. The or the spring elements may be formed as helical compression springs surrounding the pins. This achieves a symmetrical introduction of force and a space-saving arrangement.

Fig. 1

eine schematische Darstellung eines Kanalsystems,

Fig. 2

eine Draufsicht auf einen Deckel einer Schachtabdeckung,

Fig. 3

eine Schnittansicht einer ersten Ausführungsform,

Fig. 4

eine Detailansicht zu Fig. 3,

Fig. 5

eine Schnittansicht einer weiteren Ausführungsform,

Fig. 6

eine räumliche Ansicht einer weiteren Ausführungsform,

Fig. 7

eine Detailansicht zu Fig. 6 und

Fig. 8

eine Schnittansicht einer weiteren Ausführungsform.

Further features, details and advantages of the invention will become apparent from the wording of the claims and from the following description of exemplary embodiments with reference to the drawings. Show it:

Fig. 1

a schematic representation of a channel system,

Fig. 2

a top view of a cover of a manhole cover,

Fig. 3

a sectional view of a first embodiment,

Fig. 4

a detailed view too Fig. 3 .

Fig. 5

a sectional view of another embodiment,

Fig. 6

a spatial view of another embodiment,

Fig. 7

a detailed view too Fig. 6 and

Fig. 8

a sectional view of another embodiment.

In Fig. 1 schematically a channel system 1 is shown in a heavy rainfall. Surface water from a road 2 passes through corresponding shafts 3, 4 in the channel system and is fed via channels 5, 6 a main channel 7. At a confluence point, a dome shaft 8 is formed, which is closed with a watertight manhole cover 9, so that no surface water enters the channel system 1 from there.

Trapped in the duct system air 10 collects in the upper part of the dome shaft 8 and is there pressurized by the water without being able to escape through the manhole cover 9 can. As stated above very high pressures can occur, which leads to a violent escape in the worst case destruction of the manhole cover 9 and its surroundings.

According to the invention, it is therefore provided to provide the manhole cover 9 with a pressure relief device.

In Fig. 2 a lid 11 of a manhole cover according to the invention is shown. The circular lid has a structured top 12, in the recessed grips 13, 14 are diametrically opposed to each other. The lid 11 is further provided with round openings 15 which are arranged on a circular line.

In Fig. 3 the lid 11 is shown in side sectional view, each with a pressure relief device 16 is disposed in the openings 15. Furthermore, ribs 18 formed on an underside 17 of the lid 11 can be seen, which open into a centric, cylindrical wall 19. Locking latches 20 are arranged on the underside of the cover 11, wherein a total of four evenly distributed over the circumference of the lid 11 locking bolt 20 are provided, but in the illustration after Fig. 3 only two locking latch 20a, 20b can be seen. At the outer edge of the lid 11, this has on its underside 17 a circumferential contact surface 21 for abutment against a frame, not shown, of the manhole cover 9.

In Fig. 4 is a detail view too Fig. 3 shown. In the opening 15, the pressure relief device 16 is arranged, which is designed in the form of a cap 22 which is pressed into the opening 15. By a corresponding shaft-side overpressure, the cap 22 can be destroyed in the manner of a bursting cap or ejected from the opening 15. This ensures a quick pressure reduction in the shaft.

The cap 22 has a relatively thick base 23 with conical edges 24, wherein the edges 24 are inclined at the same angle as side edges 25 of the opening 15. Accordingly, between the edges 24 of the cap 22 and the side edges 25 of Opening 15 get a surface contact, which is sufficiently tragwasser- and odor-proof.

The cap 22 terminates flush with the top 12 of the lid 11. On the underside, the cap 11 has a cylindrical wall 26, which has an outwardly projecting escapement 27 in the form of a circumferential bead on its end facing away from the base end. The wall 26 serves to facilitate insertion of the cap 22 in the opening 15 and comes with a lower end of the side edges 25 of the aperture 15 in contact. As a result, it ensures a play-free hold of the cap 22 in the opening 15. In this case, an unauthorized removal of the cap 22 is prevented by the escapement 27.

The cap 22 is pressed into the opening 15 and thus frictionally and frictionally held tightly in the opening 15, wherein a piercing of the cap 22 from the top 12 to the bottom 17 is prevented by the inclined side edges.

In Fig. 5 an alternative or additional embodiment of the pressure relief device 16 is shown, wherein the cap 22 is formed substantially plate-shaped and rests on a circumferential projection 28 of the lid 11. The cap 22 is stepped according to its edge 24 formed.

Centrally attached to an inner side of the cap 22, a pin 29 which is guided by a arranged on the underside 17 of the lid 11 cage 30. The pin has at its free end an adjustable stop 31, wherein between the cage 30 and the stop 31, a spring element 32 is arranged in the form of a helical compression spring. The spring element 32 exerts a force in the closing direction on the cap 22 via the pin 29, so it pulls it into the opening 15, so to speak. This ensures a secure, watertight closure of the opening 15 through the cap 22. The spring force can be adjusted so that both a traffic-proof attachment and an optimal opening pressure for the valve function is achieved.

While in Fig. 5 an embodiment is shown in which only a central opening in the lid 11 and accordingly only a spring-loaded cap 22 is provided, shows Fig. 6 an embodiment with a plurality of openings 15 and pressure relief devices 16. The caps 22 have compared to the embodiment according to Fig. 4 a reduced Diameter, but are otherwise designed similar. In this case, each aperture 15 is associated with a cap 22 and a coaxially arranged cage 30.

In Fig. 7 is the pressure relief device 16, as in the embodiment according to Fig. 6 is used, shown in an enlarged sectional view. The plate-shaped cap 22 has on its underside at its base 23 a thickening 33. This is formed from a plastic and provides for an improved sealing and for a simplified attachment of the pin 29 to the cap 22. The pin 22 is guided by a arranged on the bottom 17 of the lid 11 cage 30 and has at his End of a designed as a nut stop 31. In this case, a spring element designed as a helical compression spring is clamped between the stop 31 and the cage 30 and pulls the cap 22 into the opening 15. In this embodiment as well as in the embodiment according to Fig. 5 the cap 22 acts as a valve plate of a spring-loaded overload valve.

Fig. 8 shows a further embodiment of the manhole cover 9 according to the invention, in which the locking bolt 20 are movably connected to the lid 1, that the lid 11 perpendicular to its extension relative to the locking bolt 20 against a force applied by spring elements 32 spring force of his investment in the frame, not shown can remove. The lid 11 thus acts as a valve plate of a spring-loaded Übelastrventils. The locking bolt 20 take over the function of the cages 30 in the previous embodiments. Accordingly, the pin 29 is guided in each case by a locking bolt 20, wherein in each case a spring element between the pin 29 located on the stop 31 and the locking bolt is clamped. The lid 11 is pulled into the frame, not shown, and held accordingly safe. The spring force can be adjusted so that both a traffic-proof attachment and an optimal opening pressure for the valve function is achieved.

The invention is not limited to one of the above-described embodiments, but can be modified in many ways.

In addition to the positions shown, the pressure relief device may also be positioned at other locations of the lid. Any number of pressure relief devices may be provided, with a symmetrical arrangement appears advantageous. In addition to the illustrated embodiments of the pressure relief device as a kind of bursting cap or as a spring-loaded overload valve also additional designs are conceivable, for example the use of an elastomeric sealing element. It can be influenced by the choice of the material of the cap, preferably plastic or metal, the holding forces and the sealing effect.

All of the claims, the description and the drawings resulting features and advantages, including design details, spatial arrangements and method steps may be essential to the invention both in itself and in various combinations.

LIST OF REFERENCE NUMBERS

1.

channel system

Second

Street

Third

shaft

4th

shaft

5th

channel

6th

channel

7th

main channel

8th.

manhole

9th

manhole cover

10th

air

11th

cover

12th

top

13th

grip

14th

grip

15th

perforation

16th

Pressure relief device

17th

bottom

18th

ribs

19th

wall

20th

locking latch

21st

contact surface

22nd

cap

23rd

Floor space

24th

margins

25th

margins

26th

wall

27th

bead

28th

head Start

29th

pen

30th

Cage

31st

attack

32nd

spring element

33rd

thickening

Claims (16)

Manhole cover with a lid (11) and a frame, wherein the lid (11) can be applied watertight to the frame, characterized in that the manhole cover (9) has a pressure relief device (16). Manhole cover according to claim 1, characterized in that the cover (11) has at least one opening (15) in which the pressure relief device (16) is arranged. Shaft cover according to claim 1 or 2, characterized in that the opening (15) is arranged centrally in the cover (11) and / or that the cover (11) has a plurality of apertures (15). Manhole cover according to one of the preceding claims, characterized in that on a lower side (17) of the lid (11) in particular radially extending ribs (18) are formed. Manhole cover according to one of the preceding claims, characterized in that a wall (19) surrounds the centrally formed opening (15). Manhole cover according to one of the preceding claims, characterized in that the pressure relief device (16) is designed as a cap (22) whose outline is adapted to the shape of the opening (15) and which can be inserted tightly into the opening (15). Manhole cover according to claim 6, characterized in that the aperture (15) has inclined side edges (25), wherein the cap (22) is correspondingly conical at its edges (24). Manhole cover according to claim 6 or 7, characterized in that the cap (22) has a base (23), from the inside of a circumferential, in particular cylindrical wall (26) emanates. Manhole cover according to claim 8, characterized in that on the wall (26) at least one outwardly projecting escapement (27) is arranged, which is designed in particular as a circumferential bead. Manhole cover according to one of claims 6 to 9, characterized in that the cap (22) comprises a plastic material. Shaft cover according to one of claims 6 to 10, characterized in that the cap (22) is designed as a spring-loaded closure for the opening (15). Manhole cover according to claim 11, characterized in that the cap (22) on an inner side at least one pin (29) which is guided by a on the underside (17) of the lid (11) arranged cage (30), wherein the pin (29) is arranged in particular centrally on the cap (22). Manhole cover according to Claim 12, characterized in that the pin (29) has a stop (31), which is adjustable in particular via a thread pairing, a spring element (32) being clamped between the stop (31) and the cage (30). Shaft cover according to one of the preceding claims, characterized in that on the underside (17) of the lid (11) locking bolt (20) are arranged for attachment to the frame. Manhole cover according to one of the preceding claims, characterized in that the cover (11) is movably connected to the locking latches (20), the locking latches (20) being loaded by spring elements (32) in the direction of the cover (11). Manhole cover according to Claim 15, characterized in that pins (29) fixedly connected to the cover (11) are guided through the locking latches (20), the pins (29) having a particularly adjustable stop (31) and the spring element (32). between the locking bolt (20) and stop (31) is clamped.

Images