This disclosure relates to a part of an inspection chamber, to an inspection chamber, and to methods of producing these.

Inspection chambers are frequently placed in ground holding groundwater. Consequently, they are exposed to groundwater pressure over extensive periods of time. This exposure may eventually lead to situations wherein the functional properties of an inspection chamber are negatively affected. In general, there is a desire to increase the longevity of an inspection chamber.

There is a need for an inspection chamber and/or an inspection chamber part that addresses at least one of the abovementioned shortcomings. There is also a need for a method for producing such an inspection chamber and an inspection chamber part. Embodiments are defined by the claims below.

GENERAL DESCRIPTION

One aspect of this disclosure relates to an inspection chamber part for placing in ground holding groundwater. The part comprises a cavity for receiving ground water and having a cavity shape. The shape is not particularly limited. The point is that groundwater may flow in and out of the cavity. The cavity is partially confined by a cavity wall for retaining ground water in the cavity. The cavity wall is configured to resist the groundwater pressure. The inspection chamber part further comprises a reinforcement member for providing additional stiffness for maintaining a shape of a circumference of at least a part of the cavity wall.

As the reinforcement member provides additional stiffness to the inspection chamber part, the shape of said circumference of at least a part of the cavity wall, in particular, is maintained for a longer period of time. This increases the inspection chamber part's longevity. The circumference may be the circumference of the entire cavity wall or it may be the circumference of a part thereof, for example, of a dome- shaped part of the cavity wall.

When the mentioned part of the cavity wall pertains to the entire cavity wall, the reinforcement member is not a part of the cavity wall. For other embodiments, i.e., when the mentioned part of the cavity wall pertains to less, i.e., to a "true" part of the cavity wall (e.g., to a dome-shaped section of the cavity wall) , the reinforcement member may, however, also fully or partially be a part of the cavity wall itself.

The cavity's configuration to receive groundwater is to be understood as a configuration which is provided despite the presence of the reinforcement member. In other words, groundwater may, hence, circulate between the cavity and outside of the inspection chamber part. The reinforcement member does not block the groundwater passage in and out of the cavity. A groundwater pressure inside of the cavity (when the inspection chamber part is placed in ground holding groundwater) filled with groundwater and outside of the part is therefore substantially the same. The reinforcement member is therefore preferably not asymmetrically exposed to

groundwater pressure. This increases the longevity thereof. Further, the cavity wall maintains its role of serving as an important pressure barrier for resisting the groundwater. This increases the longevity of the inspection chamber part. The inspection chamber part is preferably a footing and/or a base part of an inspection chamber. When an inspection chamber is put in place for use, it is oriented such that it rests on the footing and/or base part (i.e., the inspection chamber part) . Preferably, the cavity is oriented during use of the inspection chamber part such that ground water that enters the cavity is in contact with the cavity wall such that the cavity wall prevents the ground water from rising any further. The reinforcement member is preferably configured to increase stiffness of the cavity wall. However, the reinforcement may, alternatively or in addition thereto, be configured to increase the stiffness of any other section of the inspection chamber part such as a sidewall or a base part directly or indirectly connected to the cavity wall.

Preferably, the cavity wall comprises at least one dome- shaped section. The dome-shaped section is especially suited to resist groundwater pressure. Tension in the wall resulting from applied pressure is distributed particularly

homogeneously. The entire cavity wall may consist of one dome-shaped section.

According to some embodiments, the cavity wall and the reinforcement member are integrally formed. Put differently, the cavity wall and the reinforcement are continuously connected, i.e., they are made as one piece. The efficiency in producing the inspection chamber part may thus be increased. In fact, the inspection chamber part may also be integrally formed with any other part of an inspection chamber. The entire inspection chamber comprising the part may, but need not, be formed as one piece.

According to some embodiments, the cavity wall comprises multiple dome-shaped sections. The term "multiple" refers to two or more. Preferably, the cavity wall comprises a central dome-shaped section surrounded by a plurality of concave and/or dome- shaped sections. This wall form is particularly advantageous as the surrounding concave and/or dome-shaped sections may increase the stiffness of the circumference of the central dome-shaped section. In particular, this configuration improves upon a fragile connection area between a single dome-shaped section and a base part side wall which might exist if the cavity wall were constituted of a single dome- shaped section. Therefore, the durability, especially

regarding the resistance against shape deformations of the central dome-shaped section, may be higher than the analogous durability of a cavity wall which consists of one dome-shaped section . According to some embodiments, the part further comprises a side wall, and at least one of the surrounding concave and/or dome-shaped sections is located between the side wall and the central dome-shaped section and connects these. This is advantageous as the durability is improved, especially at the region between the sidewall and the central dome-shaped section. Preferably, all of the surrounding concave and/or dome-shaped sections are located between the side wall and the central dome-shaped section and connect these. Preferably, the central dome-shaped section is larger than each of the surrounding concave and/or dome-shaped sections. According to some embodiments, the central dome-shaped section is larger than the sum of all of the surrounding concave and/or dome-shaped sections.

The reinforcement member may comprise at least one or may comprise all of the surrounding concave and/or dome-shaped sections. In other words, the reinforcement member may be a part of the cavity wall. In this case, the part of the cavity wall referred to with respect to the additional stiffness for maintaining the shape of a circumference thereof, is not the entire cavity wall itself but a "true" part thereof. The circumference of the part of the cavity wall, the shape of which is maintained, may then, e.g., be the circumference of a central dome-shaped section.

According to a preferred embodiment, the maximal width (a) of each of the surrounding concave and/or dome-shaped sections is larger than a maximal thickness (t) of the cavity wall.

The "maximal width" refers to the width of the section's cavity configured to receive a fluid such as groundwater.

This further increases resistance against pressure-induced shape deformations and, hence, the longevity of the

inspection chamber part.

Preferably, at least one of the dome-shaped sections has the shape of a part of a sphere. It is especially preferable for the central dome-shaped section (if present) to have the shape of a part of a sphere. Alternatively, the shape may resemble the shape of a part of a sphere. For example, the shape may comprise polygonal parts which together approximate the shape of a part of a sphere. According to some

embodiments, all of the dome-shaped sections have the shape of a part of a sphere (or a "similar" shape) . The shape of a part of a sphere (or a shape approximating this shape) especially promotes the longevity the inspection chamber part, e.g., as tension resulting from applied pressure is distributed particularly homogeneously.

The cavity wall is preferably at least partially concave- shaped or hollowed-inward shaped.

The reinforcement member may comprise (or consist of) a reinforcement plate which is connected to another section of the inspection chamber part. For example, the reinforcement member may comprise the reinforcement plate and additionally comprise a part or parts of the cavity wall.

The reinforcement plate may have a substantially flat shape but may also have a different shape, e.g., the shape of a part of a sphere. The reinforcement member may also have stiffening members such as stiffening ribs on it.

The use of a reinforcement plate as an additional

reinforcement member is particularly useful when the

inspection chamber part is to be used at deeper groundwater levels, e.g., between 3 and 5 meters. When the inspection chamber part is used at a level of 3 meters or less, the cavity wall may also provide enough stiffness without an additional reinforcement plate.

According to some embodiments, the reinforcement plate is connected to the another section of the inspection chamber part by a weld. The inspection chamber part may comprise a side wall, and the reinforcement plate may be connected to the side wall by means of a weld.

According to some embodiments, the reinforcement plate comprises an opening configured to let fluid pass through the reinforcement plate. The reinforcement plate preferably comprises a plurality (i.e., two or more) such openings. This is a possibility of realizing the cavity's configuration to receive a fluid such as groundwater (despite the

reinforcement member's presence).

The inspection chamber part is preferably configured to allow fluid flow in and out of the cavity along one or several of the surrounding concave and/or dome-shaped section (s). This may be realized, e.g., by matching the positions of the surrounding concave and/or dome-shaped sections with openings in the reinforcement plate. In particular, only one, two, several or all of the surrounding concave and/or dome-shaped sections may allow for a fluid communication. In other words, each of the surrounding concave and/or dome-shaped sections may be understood to constitute an "open" or a "closed pocket". In addition thereto, or alternatively, the

reinforcement plate may, e.g., not extend as far so as to cover the surrounding concave and/or dome-shaped sections. In other words, the reinforcement plate may be connected to the cavity wall at positions between the central dome-shaped part and the surrounding concave and/or dome-shaped parts. This connection may e.g. be one or several welds, and the

connection may not prevent fluid communication between the "central cavity" defined between the central dome-shaped part and the reinforcement plate and the one or several

"peripheral cavities" at least partially confined by the surrounding concave and/or dome-shaped part(s). The reinforcement plate and/or the cavity wall may be

provided with at least one stiffening rib. This further increases the stiffness, thus additionally promoting the longevity of the inspection chamber part.

The inspection chamber part may further comprise a plate, wherein the cavity wall is the cavity-facing wall of said plate. Said plate may, e.g., be curved so as to conform take on the shape of a part of a sphere or a similar shape, i.e., an "approximating" shape, for example, including polygonal sections jointly approximating a partial sphere-like shape.

According to some embodiments, a maximum height of the central dome-shaped section (h) is equal to or larger than 2% of a maximal width (d) of a contour of the central dome- shaped section (h/d ≥ 0.02), wherein the maximum height is defined as a maximum shortest distance between a point on the cavity wall and a surface comprising the contour of the central dome-shaped section.

The maximal width of the contour of the central dome-shaped section is typically the diameter of a circle-shaped

surrounding contour. The "maximum height of the cavity" may be the maximum distance from the surface containing the contouring circumference circle to a point on the sphere, a part of which constitutes the shape of the cavity wall.

A maximal angle a between points on the contour may be equal to or smaller than 90°, the angle a being defined with respect to the center of the sphere, a part of which

constitutes the shape of the cavity wall. The cavity wall may comprise a largest dome-shaped section, and the largest closed contour may be a contour edge of the largest dome-shaped section. The height (h) may lie in a range of 0.02 to 0.35 times the maximal width (d) of the contour (0.02 ≤ h/d ≤ 0.35) .

The height (h) may lie in a range of 0.02 to 0.35 times the maximal width (d) of the contour (0.02 ≤ h/d ≤ 0.35) . The value d/h preferably lies in a range between 3 and 12 (3 ≤ d/h ≤ 12)) when the inspection chamber part (or of the inspection chamber with said part) lies in a range of 1100 to 1300 cm (preferably, around 1250 cm) . The value d/h

preferably lies in a range between 4 and 15 (4 ≤ d/h ≤ 15) ) when the inspection chamber part (or of the inspection chamber with said part) lies in a range of 900 to 1100 cm (preferably, around 1000 cm) . The value d/h preferably lies in a range between 12 and 41 (12 ≤ d/h ≤ 41)) when the inspection chamber part (or of the inspection chamber with said part) lies in a range of 800 to 900 cm (preferably, around 850 cm) .

The disclosure relates to inspection chamber parts including any one or any combination of the formerly discussed features (in so far compatible) which is mountable to another

component of an inspection chamber. It also relates to inspection chamber parts including any one or any combination of the formerly discussed features (in so far compatible) which are mounted to another component of an inspection chamber. "Mounted" can in this context, e.g., be understood as reversibly or fixedly mounted to or as integrally

connected with another part. The inspection chamber part may at least partially be made by roto-molding . In fact, the entire inspection chamber part may be produced by roto-molding. However, the disclosure also relates to inspection chamber parts made by other methods, for example, involving injection molding.

The reinforcement member may comprise polypropylene and/or polyethylene . The disclosure further also relates to an inspection chamber comprising an inspection chamber part according to any one of the formerly discussed embodiments. The inspection chamber may be integrally formed (as one piece) with the inspection chamber part or it may comprise additional separate pieces. The inspection chamber may at least partially be made by roto-molding. In fact, the entire inspection chamber may be produced by roto-molding. However, the disclosure also relates to inspection chambers made by other methods, for example, involving injection molding.

Further, the disclosure relates to a method for manufacturing an inspection chamber part or an inspection chamber according to according to any one of the formerly discussed

embodiments .

Additional advantages and features of the present disclosure, that can be realized on their own or in combination with one or several features discussed above, insofar as the features do not contradict each other, will become apparent from the following description of preferred embodiments.

The description is given with reference to the accompanying drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS

In the following description accompanying the various figures, like parts are denoted with like reference signs.

Fig. 1A is a side view (partial cross-section) of an embodiment of an inspection chamber part;

Fig. IB is a side view (partial cross-section) of an embodiment of an inspection chamber part;

Fig. 2A is a perspective view of an embodiment of an inspection chamber part;

Fig. 2B is a perspective view of an embodiment of an inspection chamber part;

Fig. 3A is a perspective view of an embodiment of an inspection chamber;

Fig. 3B is a top view of an embodiment of an inspection chamber;

Fig. 3C is a cross-sectional view of an embodiment of an inspection chamber;

Fig. 4A is a perspective view of an embodiment of an inspection chamber part;

Fig. 4B is a perspective view of an embodiment of an inspection chamber part; and Fig. 5 depicts an embodiment of an inspection chamber part .

Fig. 1 is a side view (partial cross-section) view of an embodiment of an inspection chamber part 1 for placing in ground holding ground water.

The part 1 comprises a cavity 2 for receiving ground water. Further, the part 1 comprises a plate, one side of which constitutes a cavity wall 10 which partially confines the cavity 1. The cavity wall 10 is configured to retain the ground water in the cavity 2.

Further, the part 1 of Fig. 1A comprises reinforcing members 3 for providing additional stiffness for maintaining the shape of the cavity 2. In particular, the cavity wall 10 comprises a central dome-shaped section 11, and the additional stiffness in particular promotes maintaining the shape of the circular-shaped contour of a "true" part of the cavity, the central domes-shaped section 11. In the case of this embodiment, the reinforcing members 3 are a part of the cavity wall 10. In other words, the cavity wall 10 comprises the central dome-shaped section 11 as well as surrounding concave shaped sections forming reinforcement members 3. However, the disclosure also relates to embodiments wherein the reinforcement member comprises or consists of a component not part of the cavity wall.

Fig. IB is a side view (partial cross-section) of another embodiment of an inspection chamber part 1. To a large degree, the components of the part 1 are identical to those of the embodiment of Fig. 1A and are, hence, denoted by the same reference signs. This embodiment, however, comprises an additional reinforcement member 4 in the form of a plate welded onto the remaining part of the inspection chamber part 1. In this case, both the reinforcement members 3, forming a part of the cavity wall 10 (surrounding concave shaped sections 3), as well as a reinforcement plate 4, are provided as a "reinforcement member".

Both in the cases of Fig. 1A and IB, the respective inspection chamber parts 1 also comprise a side wall 5. All of the surrounding concave shaped sections 3 are located between the side wall 5 and the central dome-shaped section. Further, the surrounding concave shaped section 3 (i.e., the reinforcement members 3) connect the side wall 5 and the central dome-shaped section 11.

The embodiments of Fig. 1A and IB comprise the surrounding concave shaped sections 3 with maximal widths (a) larger than the thickness (t) of the cavity wall 10. The cavity wall 10 of the embodiments of Figs. 1A and IB is concave/hollowed-inward shaped when seen from below ( 1 · Θ · cL S seen from the cavity 2) .

Figs. 2A and 2B are partial perspective views of the embodiments of Figs. 1A and IB. As becomes apparent from Fig. IB, a fluid such as ground water can flow in and out of the cavity 2 through fluid ports/openings 40. In other words, the ports 40 constitute openings configured to let fluid pass the reinforcement plate 4. A fluid may thus flow in and out of the cavity through the "surrounding cavities" associated with the surrounding concave shaped sections 3 of the cavity wall 10. Fig. 5 shows a number of geometric values describing an embodiment of an inspection chamber part. In particular, the thickness t of the cavity wall 10 (a thickness of a plate in the case of this embodiment) is smaller or equal to a maximal width a of the surrounding concave shaped sections/reinforcing members 3. Further, the cavity wall 10 comprises a central dome-shaped section 11. The central dome- shaped section 11 has the shape of a part of a sphere. The radius R of the dome-shaped section is the radius of the circle encircled by the contour of the central dome-shaped section 10 of said sphere, R=2 p sin a, wherein p is the radius of the sphere, and a is the maximal angle of half of the region swiped by the section of the sphere covered by the central dome-shaped section 11. R is larger to or equal to the maximal width a of the surrounding concave shaped sections .

Further, the section of the central dome-shaped section 11 swipes a region of the sphere with a maximal angle 2a ≤ 180°. In addition, a height h of the central dome-shaped section 11 is ≥ than the thickness t of the cavity wall 10 and ≤ than the radius p of the sphere, part of which describes the shape of the cavity wall central dome-shaped section 10. The embodiment of Figs. 1A and 2A is integrally formed as one piece and is manufactured by roto molding. However, the disclosure also relates to embodiments which are manufactured differently, e.g., involving the use of injection molding.

Except for the reinforcement member 4, also the embodiments of Figs. IB and 2B are manufactured integrally, i.e., as one piece, by roto-molding . Fig. 3A depicts a cross-sectional view of an inspection chamber 6. This inspection chamber 6 comprises an inspection chamber part 1. Fig. 3B is a top view of the inspection chamber 6, and Fig. 3C is a sectional view along the line B-B in Fig. 3B. The inspection chamber part 1 at the lower end of the inspection chamber 6 can be seen in Fig. 3C. The inspection chamber part 1 may, for example, be formed as the one of Figs. 1A and 2A or as the one of Figs. IB and 2B. In the case of the embodiment of Figs. 3A to 3C, the inspection chamber part 1 is an integral part of the inspection chamber 6, at least in so far as the side walls 5 of the part 1 and the remainder of the inspection chamber 6 are made as one piece (formed by roto-molding) . However, this disclosure also relates to inspection chamber parts 1 which are made separately and are removable or fixedly mountable or mounted to another component of an inspection chamber.

Figs. 4A and 4B show a cross-sectional view from below and (at least partially) from above, respectively, of an embodiment of an inspection chamber part 1. This embodiment comprises a reinforcement member in the form of a reinforcement plate 4 which is welded onto the base part of the inspection chamber part 1. The reinforcement member 4 is provided with openings 40 for allowing fluid to pass in an outside of the cavity 2. In the case of this embodiment, the cavity wall is made of a single dome-section which is hollowed inward/concave-shaped (when seen from below, i.e., from the side of the cavity 2) and has the shape of a part of a sphere (see Fig. 4B) . Many additional variations and modifications are possible and are understood to fall within the framework of the disclosure .