EP1277888A1

EP1277888A1 - Roadway manhole cover

Info

Publication number: EP1277888A1
Application number: EP02015945A
Authority: EP
Inventors: Luca Belli
Original assignee: Fonderie Viterbesi Di Belli & C SNC
Current assignee: Fonderie Viterbesi Di Belli & C SNC
Priority date: 2001-07-20
Filing date: 2002-07-17
Publication date: 2003-01-22
Also published as: ITTO20010715A1; ITTO20010715A0

Abstract

A roadway manhole cover (1) defined by a substantially four-sided frame (2), and by one or more four-sided cover members (3) having a solid or grid structure and connected by hinge assemblies (4) to only one side (2a) of the frame (2), so as to leave three sides of the frame (2) clear, and so facilitate access to the roadway.

Description

The present invention relates to a roadway manhole cover.
Roadway manhole covers are normally defined by a cover or grid comprising a four-sided frame and two or more right-triangular plates hinged along a cathetus to the frame. More specifically, the triangular plates are hinged to two opposite sides of the four-sided frame to permit access to the manhole from the other two sides.
In another embodiment, the triangular plates are hinged to two adjacent sides of the four-sided frame, the other two sides being left clear for easier access to the manhole from two adjacent sides forming a right-angle, as opposed to two opposite sides.
Nevertheless, access for underground roadwork is still awkward, especially when it also involves handling bulky equipment.
It is an object of the present invention to provide a roadway manhole cover designed to solve the problems of the known state of the art.
According to the present invention, there is provided a roadway manhole cover comprising a substantially four-sided frame, and one or more cover members having a solid or grid structure and connected to said frame by at least one hinge assembly; said cover being characterized in that said cover members are substantially four-sided in shape, and said frame has only one side on which to hinge said cover members.
In a preferred embodiment, each of said cover members of the cover according to the present invention comprises at least one groove located along one edge and such as to cooperate hermetically by means of a joint with an adjacent cover member.
Three of the four sides of the frame are thus left clear to permit easy access to the manhole regardless of the number of cover members required.
In known roadway manhole covers, the cover members are connected to the frame by two hinge assemblies, each of which comprises a pin fixed at both axial ends to a portion of the frame, and a ring fitted about the pin and to the cover member. In hinge assemblies of the above type, the ring fitted to the respective pin has both an axial clearance along the pin, and a radial clearance by being larger than the pin. The presence of such clearances in roadway manhole cover hinge assemblies results in a number of drawbacks, mainly due to the considerable weight of each cover member.
In particular, the axial clearance between the ring and the pin may result in misalignment of the cover members, thus preventing the cover as a whole from being closed, and so calling for realignment of the cover members. Whereas the radial clearance between the ring and the pin may result, due to friction, in unstable, and therefore potentially dangerous, locking of the cover member, due to the cover member rotating laterally.
It is a further object of the present invention to provide a roadway manhole cover hinge assembly designed to solve the problems of the known state of the art.
According to the present invention, there is provided a hinge assembly for roadway manhole covers as described above, said hinge assembly comprising a moving part integral with said cover member, and a rotation seat for housing said moving part and formed in one side of said frame; said hinge assembly being characterized in that said moving part comprises a substantially rectangular-section pin; and said rotation seat comprises a rotation slot for housing said pin and defined crosswise to said side by at least one wall facing outwards of said frame and having a convex portion for forcing said pin to travel along a substantially C-shaped path.
This therefore minimizes the clearances on the hinge assemblies, thus solving the problems of known hinges, while at the same time the particular design of the rotation slot keeps the cover member in a stable open position.
A non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:
Figure 1 shows a top plan view of a preferred embodiment of the roadway manhole cover;
Figure 2 shows a section along line II-II in Figure 1;
Figure 3 shows a larger-scale detail of Figure 2 in a different operating position;
Figure 4 shows a section of a preferred embodiment of the hinge assembly according to the present invention.
Number 1 in Figure 1 indicates as a whole a roadway manhole cover comprising a rectangular frame 2; and two rectangular cover members 3a, 3b, each connected by two hinge assemblies 4 to one side 2a of frame 2.
As shown in Figures 2 and 3, each cover member 3 has an edge with a groove 5. More specifically, cover members 3a and 3b have respective grooves 5 facing opposite ways, so as to form, in the closed position, a joint 6 between the two grooves 5 to close cover 1 hermetically. This is important to prevent water from entering underneath the roadway and possibly damaging electric or other types of cables. Joint 6 also provides for keeping the whole cover closed by locking only one of the cover members - in the case of the cover shown in the drawings, cover member 3a - by means of a bolt (shown schematically and indicated 7).
Number 4 in Figure 4 indicates as a whole a hinge assembly defined by a rotation seat 8 formed in side 2a of frame 2, and by a moving part 9 integral with the corresponding cover member 3.
Moving part 9 comprises a central body 10; a rectangular-section pin 11 defined by two portions (only one shown in Figure 4) extending linearly on opposite sides of central body 10; and a stop member 12, which extends from central body 10, is perpendicular to pin 11, and cooperates with a portion 13 of rotation seat 8 to arrest rotation of cover member 3 in the closing direction.
Rotation seat 8 comprises two rotation slots 14, each of which, in use, houses one of the two portions of pin 11. Each rotation slot 14 comprises an inlet opening 15 for the portion of pin 11, and is defined, crosswise to side 2a, by a first flat wall 16 facing inwards of frame 2, and by a second inner wall 17 facing first wall 16 and having a convex portion 18 on which pin 11 slides. More specifically, convex portion 18 comprises a flat top portion 18a facing inlet opening 15, and a bottom portion 18b having a recess 19. When cover member 3 is in the fully-open position, an edge of pin 11 cooperates with recess 19 to prevent the corresponding cover member 3 from closing accidentally.
Rotation seat 8 also comprises two catch channels 20, each of which faces a corresponding rotation slot 14, on the opposite side to inlet opening 15. The presence and location of the two catch channels 20 provide for keeping rotation slots 14 clean by preventing dirt from accumulating in slots 14.
The roadway manhole cover according to the present invention therefore provides for much easier access, by the cover members, unlike the known state of the art, all being connected to one side of the frame, but without impairing the safety and efficiency of the cover.
Moreover, the technical characteristics of the innovative hinge described minimize clearance between the relatively moving parts, thus eliminating the aforementioned drawbacks of the known state of the art.

Claims

A roadway manhole cover (1) comprising a substantially four-sided frame (2), and one or more cover members (3) having a solid or grid structure and connected to said frame (2) by at least one hinge assembly (4); said cover (1) being characterized in that said cover members (3) are substantially four-sided in shape, and said frame (2) has only one side (2a) on which to hinge said cover members (3).
A cover as claimed in Claim 1, characterized in that each of said cover members (3) comprises at least one groove (5) located along one edge and such as to cooperate hermetically by means of a joint (6) with an adjacent cover member (3).
A cover as claimed in Claim 1 or 2, characterized in that each of said cover members (3) is connected to said side (2a) of the frame (2) by two hinge assemblies (4).
A hinge assembly (4) for roadway manhole covers as claimed in any one of the foregoing Claims, said hinge assembly (4) comprising a moving part (9) integral with said cover member (3), and a rotation seat (8) for housing said moving part (9) and formed in one side (2a) of said frame (2); said hinge assembly (4) being characterized in that said moving part (9) comprises a substantially rectangular-section pin (11); and said rotation seat (8) comprises a rotation slot (14) for housing said pin (11) and defined crosswise to said side (2a) by at least one wall (17) facing outwards of said frame (2) and having a convex slide portion (18) for forcing said pin (11) to travel along a substantially C-shaped path.
A hinge assembly as claimed in Claim 4, characterized in that said moving part (9) comprises a central body (10), and said pin (11) is defined by two portions extending linearly on opposite sides of said central body (10); and in that said rotation seat (8) comprises a rotation slot (14) for each portion of the pin (11).
A hinge assembly as claimed in Claim 4 or 5, characterized in that each of said rotation slots (14) is defined by a flat wall (17) located opposite said convex slide portion (18).
A hinge assembly as claimed in any one of Claims 4 to 6, characterized in that said convex slide portion (18) comprises a flat portion (18a) facing an inlet opening (15) for insertion of said pin (11) inside said rotation seat (8).
A hinge assembly as claimed in Claim 7, characterized by comprising a catch channel (20) formed in said frame (2) and communicating with said rotation seat (8) on the opposite side to said inlet opening (15).
A hinge assembly as claimed in Claim 8, characterized in that said convex slide portion (18) comprises a bottom portion (18b) having a recess (19) and facing said catch channel (20).
A hinge assembly as claimed in any one of Claims 4 to 9, characterized in that said central body (10) comprises a stop member (12) which cooperates with said frame (2) when a corresponding cover member (3) is in a closed position.