Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
  • E02D29/00—Independent underground or underwater structures; Retaining walls
  • E02D29/12—Manhole shafts; Other inspection or access chambers; Accessories therefor

Definitions

• the present invention relates to a top piece for a manhole structure, comprising an access part and a cone which connects to the access part and can be placed on a manhole structure shaft with a peripheral edge on the side of the cone opposite the access part, the cone having a substantially outward curved basic shape.
• top piece Owing to the outward curved shape, the top piece in general has good resistance to pressure forces which are exerted on the top piece by the ground surrounding the manhole structure.
• the disadvantage of the known top piece is, however, that the region of the transition from the cone to the access part is more readily deformed than the cone or the access part.
• An extreme pressure load as the result of the mutually amplifying radially inward directed components of forces exerted on the transition, can cause the top piece to bend inwards at that position.
• the object of the invention is to provide a top piece which does not have this disadvantage.
• the top piece according to the invention is characterized in that in the region of the transition from the access part to the cone, a rein ⁇ forcement rib, which is substantially parallel to the plane in which the peripheral edge is situated, is provided on the outer surface of the cone, extending over the entire periphery of the cone.
• this reinforcement rib gives the cone in the region of the transition to the access part greater resistance to radially inward directed forces than is the case without said rib.
• Fig. 1 is a view, partially in section, of a manhole structure which is provided with a top piece according to the invention
• Fig. 2 is a top view of a top piece according to the invention.
• the manhole structure 1 shown in Fig. 1 is substantially cylindrical and comprises a bottom 2 on which a manhole structure shaft 3 is placed.
• the manhole structure 1 further comprises a top piece 4 which is placed on the manhole structure shaft 3.
• the top piece 4 consists substantially of two parts, a cone 5 and an access part 6. There is a sharp transition 21 between the cone 5 and the access part 6.
• Fitted around the access part 6 is a concrete ring 7, which can slide up and down over the access part 6.
• the concrete ring 7 serves as a support for a manhole cover edge 8.
• a manhole cover (not shown) of standardized dimensions, which shuts off the manhole formed by the access part, can be placed in this manhole cover edge 8.
• the top piece 4 can be placed on manhole structures for pipe systems, for example a sewer system.
• a number of connecting sockets 9 are fitted in the bottom 2 of the manhole structure l, for making the connection of the man
• the manhole structure shaft 3 and the top piece 4 are provided with shaft sockets 10, 11.
• the parts of the bottom 2 and the manhole structure shaft 3 projecting into the shaft sockets 10, 11 respectively are reinforced by means of peripheral ribs 14, 15.
• the seal between the bottom 2 and the shaft socket 10 and between the manhole structure shaft 3 and the shaft socket 11 is provided by sealing rings 12, 13.
• the access part 6 is provided with reinforcement ribs 16 on the outside.
• the dimensions of the concrete ring 7 are standardized.
• the external diameter of the access part 6 is thus determined by the internal diameter of the concrete ring 7. Owing to the large number of reinforcement ribs 16, the reinforcement ribs 16 can be small, and the internal diameter/external diameter ratio is as large as possible.
• the cone 5 has a substantially outward curved basic shape and at its underside defines a peripheral edge 17.
• the cone 5 comprises a first part 18 whose cross- sections, which are parallel to the peripheral edge 17, are substantially circular, but have different diameters, and all intersect one straight line which is substantially parallel to the axis of the access part 6.
• the first part 18 consequently has one straight generating line 20.
• the cone 5 further comprises a second part 19 which is situated between the first part 18 and the access part 6, and whose cross-sections parallel to the peripheral edge 17 are likewise circular, but do not intersect a straight line.
• the cross-sections of the first part 18 and the second part 19 of the cone parallel to the peripheral edge 17 can also be of a different shape, for example an elliptical shape.
• the shaft socket 11 increases the resistance of the peripheral edge 17 to forces in the radial direction, and thus to deformation of the peripheral edge inwards and outwards in the radial direction.
• the curved generating lines of the cone 5 will tend to stretch. Since the movement of the peripheral edge 17 is limited in the horizontal direction by the shaft socket 11 and in the vertical direction by the manhole structure shaft 3, this stretching will be evident particularly by a movement of the transition 21 radially inwards.
• a reinforcement rib 22 is provided on the outer surface of the second part 19 in the region of the transition 21.
• Said reinforcement rib 22 forms a continuous closed ring.
• a number of ribs 23 are also provided parallel to the peripheral edge 17. It can be seen in Fig. 2 that each rib 23 extends over an equal distance from the straight generating line 20 to both sides of the cone 5.
• These ribs 23 also increase the resistance of the cone 5 to compression.
• a number of slanting ribs 24, placed at an angle relative to the plane in which the peripheral edge 17 is situated, are provided in the region of the outer surface of the cone 5 lying diametrically opposite the straight generating line 20. This means that the slanting ribs 24 are substantially at right angles to the outer surface of the cone 5, which has a beneficial effect on the resistance of the cone 5 to pressure forces.
• the ribs 23 parallel to the peripheral edge 17 merge into the slanting ribs 24, each rib 23, with the exception of the two ribs 23 lying closest to the periph ⁇ eral edge 17, continuing to the next slanting rib 24.
• the two ribs 23 situated closest to the peripheral edge 17 run on and form a continuous closed ring.
• a rib 25 is provided on the outer surface of the cone 5. Said rib 25 also increases the resistance of the cone 5 to compression. Moreover, said rib 25 prevents bending of the slanting ribs 24 as a result of the vertical component of forces exerted on the slanting ribs 24.
• the ribs 23 pass smoothly into the slanting ribs 24. In this case the ribs 23 do not extend to the next slanting ribs 24.
• all slanting ribs 24 extend from the peripheral edge 17, by way of the region which is situated diametrically opposite the straight generating line 20, to the peripheral edge 17 at the other side of the top piece 4.
• the ribs 23 extend from the straight generating line 20 to the first slanting rib 24. Therefore, for all ribs 23 this is the same slanting rib 24.
• only ribs 23 which are parallel to the peripheral edge 17 are provided on the outer surface of the cone 5.
• the access part 6 can be placed either concentrically or eccentrically on the cone 5.
• two ribs which are parallel to the axis of the access part 6 can be provided on the inside of the cone 5. These ribs give additional reinforcement of the outer surface of the top piece 4.
• Rungs can be fixed between the ribs, thereby forming a ladder part, in order to facilitate access to the manhole structure 1.
• the bottom 2, the manhole structure shaft 3 and the top piece 4 are in practice preferably made of synthetic material.

Landscapes

• Engineering & Computer Science (AREA)
• Environmental & Geological Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Paleontology (AREA)
• Civil Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Underground Structures, Protecting, Testing And Restoring Foundations (AREA)
• Sewage (AREA)
• Beans For Foods Or Fodder (AREA)
• Table Devices Or Equipment (AREA)
• Filters For Electric Vacuum Cleaners (AREA)
• Farming Of Fish And Shellfish (AREA)
• Dry Shavers And Clippers (AREA)
• Orthopedics, Nursing, And Contraception (AREA)
• Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)
• Laying Of Electric Cables Or Lines Outside (AREA)
• Earth Drilling (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19763041

Family Applications (1)

Country Status (10)

Cited By (6)

Families Citing this family (12)

Citations (5)

• 1996
  • 1996-06-19 NL NL1003376A patent/NL1003376C2/nl not_active IP Right Cessation
• 1997
  • 1997-06-17 AU AU31089/97A patent/AU3108997A/en not_active Abandoned
  • 1997-06-17 PL PL97330600A patent/PL183744B1/pl unknown
  • 1997-06-17 DE DE69711377T patent/DE69711377T2/de not_active Expired - Lifetime
  • 1997-06-17 WO PCT/NL1997/000338 patent/WO1997048859A1/en not_active Ceased
  • 1997-06-17 DK DK97926286T patent/DK0906477T3/da active
  • 1997-06-17 AT AT97926286T patent/ATE215154T1/de not_active IP Right Cessation
  • 1997-06-17 ES ES97926286T patent/ES2174261T3/es not_active Expired - Lifetime
  • 1997-06-17 CZ CZ19984073A patent/CZ295673B6/cs not_active IP Right Cessation
  • 1997-06-17 EP EP97926286A patent/EP0906477B1/en not_active Expired - Lifetime

Patent Citations (5)

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