System for fastening the cover of a manhole to the relative frame

Abstract

 System for fastening the cover of a manhole to a relative frame, which is buried in the material forming a road surface and with the cover articulated to the frame, includes: first means (10), which are carried by the cover (C) and which couple removably with corresponding second means (3) made in the frame (11).

Description

[0001] The present invention relates to devices for closing manholes.

[0002] In this particular case, the present invention concerns a system for fastening the cover of a manhole to a relative frame.

[0003] It is known that below the surface of the ground, on which roads, lay-byes, sidewalks, etc., are made, there are ducts for carrying and delivering water, gas, electricity, etc., having suitable manholes, which are accessible from the road surface by removing corresponding covers.

[0004] It is also known that below the ground surfaces, there are draining ducts communicating with the ground surface by manholes, whose covers have slots, through which passes the water possibly accumulated on the ground surface.

[0005] The cover can be snap fitted to the upper terminal portion of the manhole, or it can be hinged at one end of this portion to facilitate its raising by an operator.

[0006] In order to ensure best possible closing of the manhole, the latter can have a fastening device, usually including a rotating prismatic element, connected to the upper portion of the cover, which can be handled by a suitable box wrench and which has a tongue, situated in its lower part to engage with a corresponding seat made in the upper portion of the manhole.

[0007] The above closing system makes it necessary for the operator to have the box wrench always at hand.

[0008] It is also to be pointed out that the housing of the prismatic element is exposed to dirt, since it is made in the upper portion of the cover, thus on the walking surface of the sidewalks, or of the ground surface.

[0009] The accumulation of the dirt in the housing can make it impossible for the operator to introduce the box wrench and consequently to open the manhole cover.

[0010] The object of the present invention is to propose a system for fastening the cover of a manhole to the relative frame, which is protected from the atmospheric agents and dirt.

[0011] Another object of the present invention is to propose a system for fastening the cover of a manhole to the relative frame, which ensures fastening and unfastening of the cover without the use of special tools.

[0012] A further object of the present invention is to propose a system for fastening the cover of a manhole to the relative frame, which is extremely functional, reliable and cheap.

[0013] The above mentioned objects are obtained in accordance with the contents of the claims.

[0014] The characteristic features of the invention will be pointed out in the following description of some preferred but not exclusive embodiments, with reference to the enclosed figures, in which:

• Figure 1 is a schematic lateral and partially section view of a manhole and the corresponding cover;
• Figure 2 is a schematic view, enlarged with respect to the previous Figure, of a particularly significant element of the fastening system, in two subsequent working steps;
• Figure 3 is a schematic view of the same element shown in the previous Figure, in a subsequent characteristic positions;
• Figures 4, 5 and 6 are schematic views of corresponding embodiments of the element shown in Figures 2 and 3.

[0015] According to a preferred embodiment and with reference to Figures from 1 to 3, the reference T indicates a manhole including a frame 11, buried in the material forming a road surface (for example a road or a sidewalk) and closing cover C, articulated to the upper end of the frame 11.

[0016] First means 10, situated in the lower part C1 of the cover C, on the side opposite with respect to the hinge connection of the latter to the frame 11, cooperate with second means 3 made in the frame 11 to removably fasten the cover C to the frame 11.

[0017] The first means 10 include a first laminar element 1 and a second laminar element 2, opposite to each other, curved with the concavity turned outwards and having lower portions 1A, 2A adjacent, while the upper ends 1C, 2C are engaged, together with a cotter 4, with a trapezoidal seat 4A made in the lower part C1 of the cover C.

[0018] The group formed by the upper ends 1C, 2C and the cotter 4 defines fastening means of the first means 10 to the cover C.

[0019] The laminar elements 1, 2 removably couple with the second means, including a through hole 3, made in the upper portion of the frame 11 and having a truncated cone shape with the section decreasing upwards.

[0020] The operation of the present invention will be now explained, although easy to understand.

[0021] Beginning from a configuration, in which the manhole T is opened, an operator can close the cover C by simply following its rotation on the axis of the hinge connection, until the lower portions 1A, 2A are engaged with the hole 3.

[0022] At this point, the laminar elements 1, 2 assume a first engaging/disengaging configuration I (see Figure 2), in which they are elastically deformed and close to each other, in order to couple with the hole 3 in a substantially vertical direction, and later, a working configuration B (see Figure 3), in order to allow the removable fastening of the cover C to the frame 11.

[0023] The truncated cone shape of the hole 3 forms a stabilizing element, because it prevents an accidental disengagement of the laminar elements 1, 2 introduced into the hole.

[0024] If the manhole is closed, an operator can open the cover C by applying an upward force, preferably on the side opposite to the hinge connection side.

[0025] In this case, the laminar elements 1, 2, first in the working configuration B, assume the engaging/disengaging configuration I and, when they are completely disengaged from the hole 3, they reassume the original proportions.

[0026] According to a second embodiment, shown in Figure 4, the two laminar elements 1, 2 are made integral in one body, to define a locking body 12, whose upper portion engages with a through hole 50 made in the cover C and whose upper ends 12A, 12B, folded outwards, are placed within a recess made on the upper surface C2 of the cover and define fastening means of the first means 10 to the cover C.

[0027] A third embodiment, shown in Figure 5, differs from the first proposed embodiment by the presence of a spring 5 interposed between the laminar elements 1, 2, preferably in a region corresponding to the maximum concavity plane of the latter.

[0028] A fourth embodiment, shown in Figure 6, differs from the first proposed embodiment by the fact that the fastening means include a wedge portion 40, having in its lower part a portion 40b, basically longitudinal, and interposed between the lower portions 1A, 2A of the laminar elements 1, 2.

[0029] The upper ends of the latter, like in the first embodiment, engage, together with the wedge portion 40, with a corresponding truncated cone seat 40A made in the lower part C1 of the cover C.

[0030] It is easy to deduce from the above description that the system for fastening the cover of a manhole to the relative frame allows fastening and unfastening of the cover to and from the relative frame in easy way.

[0031] Moreover, the proposed system allows fastening and unfastening of the cover to and from the relative frame without need to use using special tools.

[0032] Further, it is understood from the above description that the fastening device is not exposed to the dirt present in the road seat or on the sidewalk, because it is made in the lower part of the cover and the frame.

Claims

1. System for fastening the cover of a manhole to the relative frame, with the cover being hinge connected to the frame, characterized in that it includes: first means (10), carried by said cover (C), to couple removably with corresponding second means (3) made in the frame (11).

2. System, as claimed in claim 1, characterized in that said first means (10) are situated on the part opposite with respect to the hinge connection of said cover (C) to said frame (11).

3. System, as claimed in claim 1 or 2, characterized in that said first means (10) include a first laminar element (1) and a second laminar element (2), opposite to each other, whose upper part is carried, through fastening means, by the lower part (C1) of said cover (C), and whose respective lower portions (1A, 2A) are adjacent; said laminar elements (1, 2) defining two configurations, respectively engaging/disengaging configuration (I), consequently to the engagement with said second means (3), in which they are elastically deformed and close to each other, and an active configuration (B), in which said cover (C) is removably fastened to said frame (11).

4. System, as claimed in claim 1 or 3, characterized in that said second means include a hole (3).

5. System, as claimed in claim 4, characterized in that said hole (3) is a through hole.

6. System, as claimed in claim 5, characterized in that said through hole (3) has a truncated cone shape, with the diameter increasing downwards.

7. System, as claimed in claim 3, characterized in that said fastening means include a wedge portion (4), which engages, together with the upper ends (1C, 2C) of said laminar elements, with a corresponding seat (4A) made in the lower part (C1).

8. System, as claimed in claim 3, characterized in that said first laminar element (1) and said second laminar element (2) are made integral in one body to define a locking body (12), fastened to the lower part (C1) of the cover (C) by fastening means.

9. System, as claimed in claim 8, characterized in that said fastening means include a second through hole (50), made in said cover (C) and engaging with the upper portion of said locking body (12), whose upper ends (12A, 12B), folded outwards, are placed within a recess made on the upper surface (C2) of the cover (C).

10. System, as claimed in claim 3, characterized in that elastic means (5) are interposed between said first laminar element (1) and second laminar element (2).

11. System, as claimed in claim 3, characterized in that said fastening means include a wedge portion (40), having in its lower part a substantially longitudinal portion (40B), interposed between said lower portions (1A, 2A) of said laminar elements (1, 2), which enter, together with said cotter (40) a corresponding seat (40A) of truncated cone shape made in the lower par (C1) of said cover (C).

Drawing