DE20204108U1 - Cover of a manhole cover and manhole cover - Google Patents

Abstract

The invention relates to a cover for a manhole covering, comprising at least one locking element (16, 18) that is provided on the cover (10). Said locking element has at least one spring-loaded arm (18) with an engagement section (18a) that can engage with part (6) of a frame (1). The invention is characterised in that the spring-loaded arm (18) is positioned in such a way that its engagement section (18a) can be displaced relative to the neighbouring section of the periphery (10a) of the cover (10) at an angle that is smaller than a right angle.

Description

Bremen,

14 March 2002

Our reference: B 2615 JK/S0l/J0

Direct dial: 0421/36 35

• · Patent attorneys.. * . · _{&psgr; t}
European Patent Attorneys
Dipl.-Ing. Günther Eisenführ
Dipl.-Ing. Dieter K. Speiser
Dr.-Ing. Werner W. Rabus
Dipl.-Ing. Jürgen Brügge
Dipl.-Ing. Jürgen Klinghardt
Dipl.-Ing. Klaus G. Göken
Jochen Ehlers
Dipl.-Ing. Mark Andres
Dipl.-Chem. Dr. Uwe Stilkenböhmer Dipl.-Ing. Stephan Keck
Dipl.-Ing. Johannes MB Wasiljeff patent attorney
Dr.-Ing. Stefan Sasse

Lawyers
Ulrich H. Sander
Christian Spintig
Harald A. Foerster
Sabine Richter

Martinistrasse 24

D-28195 Bremen

Tel.+49-10)421-36 35 0

Fax +49-10)421-337 8788 (G3)

Fax +49(0)421-328 8631 IG4)

mail@eisenfuhr.com

http://www.eisenfuhr.com

Applicant/Owner: Official reference number:

HYDROTEC Technologies GmbH & Co. KG
New registration

European Patent Attorney

Dipl.-Phys. Frank Meier

Lawyers

Rainer Boehm

Nicol A. Schrömgens, LL. M.

Munich

Patent attorneys

European Patent Attorneys

Dipl.-Phys. Heinz Nöth

Dipl.-Wirt.-Ing. Rainer Fritsche

Lbm.-Chem. Gabriele Leißler-Gerst

Dipl.-Ing. Olaf Ungerer

Patent Attorney

Dipl.-Chem. Dr. Peter Schuler

Berlin

Patent attorneys

European Patent Attorneys

Dipl.-Ing. Henning Christiansen

Dipl.-Ing. Joachim von Oppen

Dipl.-Ing. Jutta Kaden

Patent Attorney

Dipl.-Phys. Dr. Andreas Theobald

Alicante

European Trademark Attorney Dipl.-Ing. Jürgen Klinghardt

HYDROTEC Technologies GmbH & Co. KG
Düngstruper Strasse 46, 27793 Wildeshausen

Lid of a manhole cover and manhole cover

The invention relates to a cover of a manhole cover with at least one locking means provided on the cover, which has at least one spring arm with an engagement section that can be brought into engagement with a part of a frame. The invention further relates to a manhole cover with such a cover and a frame receiving it.

Manhole covers with such a locking mechanism, which usually engages in the manner of a catch or latch, are known and are widely used. For example, reference is made to WO 86/04624, which discloses a self-locking manhole cover in which the spring arm is formed on the underside of the cover on a stiffening rib and extends essentially parallel to part of the circumference of the cover.

The present invention now proposes to arrange the spring arm in such a way that its engagement portion is movable relative to the adjacent portion of the circumference of the lid at an angle smaller than a right angle.

It has been found that the construction according to the invention makes it possible to realize a locking mechanism that functions particularly effectively and is at the same time particularly easy to handle.

In particular, the engagement portion of the spring arm is movable approximately parallel to the adjacent portion of the circumference of the cover.

Preferably, the engagement portion of the spring arm extends at an angle to the adjacent portion of the cover.

In a joint development of the previously mentioned embodiments, the engagement section of the spring arm extends approximately at a right angle to the adjacent section of the cover. In the case of a substantially circular cover, the engagement section of the spring arm can extend approximately radially and in particular the spring arm can be arranged substantially radially.

To increase the spring properties, the spring arm can preferably have an arcuate section. The arcuate section can be arranged between the engagement section and another section of the spring arm and the two sections can be approximately aligned with each other.

A currently particularly preferred embodiment is characterized in that the locking means has two spring arms that are spaced apart from one another and preferably run parallel to one another at least in sections, whereby the locking effect of the locking means can be increased. In the case of an arrangement of an arcuate section on both spring arms, this should be curved outwards, whereby the distance between the two

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Spring arms and thus the design of the locking device can be kept small in this version.

The engagement section expediently has a wedge-shaped locking section, whereby the engagement takes place as a locking position. Accordingly, the locking section is provided with at least one surface inclined in the direction of engagement. In addition, it is also conceivable to form a surface on the locking section that is also inclined in the opposite direction to make it easier to release. Alternatively or additionally, it is also conceivable to form the corresponding engagement surfaces on the frame part in a wedge shape or inclined as slanted surfaces.

Preferably, the spring arm is attached to the cover with an end remote from the engagement portion.

Usually the locking mechanism is located on the underside of the lid.

If the lid is provided with stiffening ribs, the locking means should be arranged at a distance from the stiffening ribs on the lid, which results in a particularly space-saving arrangement of the locking means.

In a further embodiment, in which the cover has an engagement means for a tool, this engagement means is arranged at a distance from the locking means and is designed such that the tool can be brought into engagement with a part of the frame when engaging with this engagement means in order to apply a lever moment to the cover and thereby release the cover from the frame against the effect of the spring force of the spring arm. This embodiment thus allows the cover to be levered out of the frame with the aid of the tool without the tool acting on the locking means. The engagement means preferably has a recess through which the tool can be inserted.

Finally, it should be mentioned at this point that two locking means are usually provided on the lid, which are opposite each other and, in the case of a circular lid, radially opposite each other.

Preferred embodiments of the invention are explained in more detail below with reference to the accompanying figures. They show:

Figure 1 is a broken plan view of a frame of a

manhole cover;

Figure 2 shows a cross section through the frame of Figure 1 according to

the dot-dash line H-II shown in Figure 1;

Figure 3 is an enlarged detail view of a

Section of the frame of Figure 1 having a locking recess in the direction of the arrow shown in Figure 1

Figure 4 is a view of the underside of a cover of the

Manhole cover with a locking mechanism in a first embodiment;

Figure 5 shows a cross section through the cover of Figure 4 along

the dot-dash line V-V shown in Figure 4;

Figure 6 is a partial sectional view of the cover of Figure 4

along the dot-dash line Vl-Vl shown in Figure 4;

Figure 7 is a view of the underside of a cover of the

Manhole cover with a locking mechanism in a second design;

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Figure 8 is a partial sectional view of the cover of Figure 7

along the dotted line VIII-VIII shown in Figure 7; and

Figure 9 shows a cross section through the peripheral section of the

Cover and frame assembly with a tool for prying the cover out of the frame.

The manhole cover described below has an annular frame 1 and a matching disc-shaped cover 10. The frame 1 is shown in Figures 1 to 3 and the cover 10 with a locking mechanism in a first embodiment in Figures 4 to 6 and in a second embodiment in Figures 7 and 8.

The frame 1 shown in Figures 1 and 2 has on its inside an inwardly projecting, circumferential web 2, the upper side 2a of which forms a support surface for the cover 10 and lies in a plane which extends essentially horizontally when the frame 1 is installed. An inwardly projecting, circumferential flange-like projection 4 is attached to the web 2, which in the embodiment shown is interrupted at two opposite points by a recess 6. As can be seen in Figure 3, each of these recesses 6 is delimited on both sides of the flange-like projection 4 by upper and lower inclined surfaces 6a and 6b which taper towards one another.

The cover 10 has on its underside a web 12 running around the circumference (see in particular Figures 4, 5 and 7), with which the cover 10 rests on the upper side 2a of the surrounding web 2 of the frame 1, which serves as a support surface, when used in the frame 1. Furthermore, the cover 10 is provided on its underside with radially extending stiffening ribs 14.

At two radially opposite locations, at a distance from the ribs 14 on the underside of the cover 10, two blocks 16 are arranged,

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each of which has two spring arms 18 formed thereon. The spring arms 18 are arranged freely floating on the respective block 16 and are directed radially outwards in the direction of the circumference 10a of the cover 10. The spring arms 18 of each pair of spring arms 18 extend parallel to one another and to the cover 10 and at a distance from its underside. Accordingly, when the manhole cover is installed and the cover 10 is inserted in the frame 1, the spring arms 18 lie approximately in a horizontal plane that runs parallel to and at a distance from the plane spanned by the cover 10.

Each arrangement of the block 16 and the pair of spring arms 18 attached to it forms a locking means for locking the cover 10 to the frame 1. For this purpose, the spring arms 18 can be moved with their free ends 18a towards one another and thus in the direction of the circumference 10a of the cover 10 against the effect of an inherent restoring spring force and serve as locking elements for locking in the recess 6 of the frame 1.

In the embodiment shown in Figures 4 and 6, the spring arms 18 are designed to be straight and are provided with a wedge-shaped outer side which is formed by an inclined upper inclined surface 18b and an inclined lower inclined surface 18c, the two inclined inclined surfaces 18b and 18c tapering towards each other in an outward direction, as can be seen in Figure 6.

The cover 10 is placed on the frame 1 in such a way that the free ends 18a of the spring arms 18 are aligned with the recesses 6. The free ends 18a of the spring arms 18 initially come into contact with the upper inclined surfaces 6a of the recess 6 of the frame 1 with their lower inclined surfaces 18c. As the cover 10 continues to move on the frame 1, the upper inclined surfaces 6a of the recess 6 cause the spring arms 18 to be pressed together at their free ends 18a until they pass the narrow part of the recess 6 formed by the two inclined surfaces 6a, 6b. Accordingly, the clear width of the narrow part of the recess 6 formed by the inclined surfaces 6a, 6b is a

slightly larger than the sum of the widths of the free ends 18a of the spring arms 18, viewed in the direction of the circumference 10a of the cover 10. Until the narrow point in the recess 6 is passed, the spring arms 18 are therefore pressed together against the effect of the restoring spring force inherent in them. After passing the narrow point in the recess 6, with continued movement of the cover 10 on the frame 1, the spring force inherent in the spring arms 18 causes the spring arms to return to the position shown in Figures 4 and 6, as a result of which the free ends 18a of the spring arms 18 now come into contact with the lower inclined surfaces 6b of the recess 6 with their upper inclined surfaces 18b and in this way engage behind the sections of the flange-like projection 4 of the frame 1 that delimit the recess 6.

Thus, the spring arms 18 with their free ends 18a on the cover 10 and the recesses 6 on the frame 1 form a locking or latching lock.

Figures 7 and 8 show a second embodiment of the locking device provided on the underside of the cover 10. The spring arms 18' of this second embodiment are molded onto the underside of the cover 10 via a block 16' as in the first embodiment shown in Figures 4 and 6 and are provided in the same way on their outside with upper and lower inclined surfaces 18b ¹ and 18c'. However, the second embodiment differs from the first embodiment in that the spring arms 18" have an outwardly bent section 18d' between the free end 18a' and a section 18e' adjacent to the block 16', the bent sections 18d' of the two spring arms 18' of each pair of spring arms 18' in the second embodiment shown being symmetrical to one another and the sections 18a' and 18e' being aligned with one another. The bent sections 18d' of the spring arms 18' serve to increase the restoring spring force. With regard to the other features and in particular the arresting or latching locking effect,

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reference is made to the description of the first embodiment given above with reference to Figures 4 and 6.

To release the cover 10 placed and locked on the frame 1, a pin-shaped tool 32 is inserted through a recess 30 provided on the circumference 10a of the cover 10 and is brought into engagement with the underlying section of the frame 1 in such a way that the tool creates a lever effect that allows the cover 10 to be lifted off the frame 1, as shown in Figure 9. This lever effect must be such that the restoring spring force of the spring arms 18 is overcome and as a result, when the cover 10 is lifted off the frame 1, the free ends 18a of the spring arms 18 can move along the lower inclined surfaces 6b of the recess 6 in the direction of its narrow point. The spring arms 18 are thereby pressed together again until they pass the narrow point of the recess 6 as the cover continues to move away from the frame 1.

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Claims (17)

1. Cover of a manhole cover with at least one locking means ( 16 , 18 ; 16 ', 18 ') provided on the cover ( 10 ), which has at least one spring arm ( 18 ; 18 ') with an engagement portion ( 18a ; 18a ') which can be brought into engagement with a part ( 6 ) of a frame ( 1 ), characterized in that the spring arm ( 18 ; 18 ') is arranged such that its engagement portion ( 18a ; 18a ') can be moved relative to the adjacent portion of the circumference ( 10a ) of the cover ( 10 ) at an angle smaller than a right angle. 2. Lid according to claim 1, characterized in that the engagement portion ( 18 a; 18 a') of the spring arm ( 18 ; 18 ') is movable approximately parallel to the adjacent portion of the circumference ( 10 a) of the lid ( 10 ). 3. Lid according to claim 1 or 2, characterized in that the engagement portion ( 18 a; 18 a') of the spring arm ( 18 ; 18 ') extends at an angle to the adjacent portion of the circumference ( 10 a) of the lid ( 10 ). 4. Lid according to claim 2 and 3, characterized in that the engagement portion ( 18 a; 18 a') of the spring arm ( 18 ; 18 ') extends approximately at a right angle to the adjacent portion of the circumference ( 10 a) of the lid ( 10 ). 5. Lid according to claim 4, wherein the lid ( 10 ) is substantially circular, characterized in that the engagement portion ( 18 a; 18 a') of the spring arm ( 18 ; 18 ') extends approximately radially. 6. Lid according to claim 5, characterized in that the spring arm ( 18 ; 18 ') is arranged substantially radially. 7. Lid according to at least one of the preceding claims, characterized in that the spring arm ( 18 ') has an arcuate section ( 18 d'). 8. Lid according to claim 7, characterized in that the arcuate section ( 18 d') is arranged between the engagement section ( 18 a') and a further section ( 18 e') of the spring arm ( 18 ') and the two sections ( 18 a', 18 e') are approximately aligned with one another. 9. Lid according to at least one of the preceding claims, characterized in that the locking means has two spring arms ( 18 ; 18 ') which are spaced apart from one another and preferably run parallel to one another at least in sections. 10. Lid according to claim 8 and 9, characterized in that the arcuate section ( 18 d') is curved outwards on both spring arms ( 18 '). 11. Lid according to at least one of the preceding claims, characterized in that the engagement portion ( 18 a; 18 a') has a wedge-shaped locking portion. 12. Lid according to at least one of the preceding claims, characterized in that the spring arm ( 18 ; 18 ') is fastened to the lid ( 10 ) with an end remote from the engagement portion ( 18 a; 18 a'). 13. Lid according to at least one of the preceding claims, characterized in that the locking means ( 16 , 18 ; 16 ', 18 ') is arranged on the underside of the lid ( 10 ). 14. Lid according to at least one of the preceding claims, in which the lid ( 10 ) is provided with stiffening ribs ( 14 ), characterized in that the locking means ( 16 , 18 ; 16 ', 18 ') is arranged at a distance from the stiffening ribs ( 14 ) on the lid ( 10 ). 15. Lid according to at least one of the preceding claims, in which the lid ( 10 ) has an engagement means ( 30 ) for a tool ( 32 ), characterized in that this engagement means ( 30 ) is arranged at a distance from the locking means ( 16 , 18 ; 16 ', 18 ') and is designed such that the tool ( 32 ) can be brought into engagement with a part of the frame ( 1 ) at the same time when engaging with this engagement means ( 30 ) in order to apply a lever moment to the lid ( 10 ) and thereby release the lid ( 10 ) from the frame ( 1 ) against the action of the spring force of the spring arm ( 18 ; 18 '). 16. Lid according to claim 15, characterized in that this engagement means ( 30 ) has a recess. 17. Manhole cover with a cover ( 10 ) according to at least one of the preceding claims and with a frame ( 1 ) for receiving the cover ( 10 ).