EP2084333B1

EP2084333B1 - Kit for the adjustment of manholes for pits

Info

Publication number: EP2084333B1
Application number: EP07765473A
Authority: EP
Inventors: Bruno Zanatta
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-17
Filing date: 2007-06-18
Publication date: 2013-03-06
Anticipated expiration: 2027-06-18
Also published as: WO2008046668A1; ITRM20060564A1; PL2084333T3; EP2084333A1

Description

The present invention relates to a kit for the adjustment of manholes for road pits, such as sewage pits and the like, and to a respective method for the adjustment of manholes.
As everyone knows, pits use manholes for allowing the closing thereof and the access thereto in case of maintenance needs.
Normally, manholes are formed by a frame, generally made of cast iron, disposed resting on the mouth of the pit, onto which a cover is laid so as to deny the access to the sewage system and allow the passage of vehicles onto the manhole itself.
A very important feature during the setting of manholes consists in the laying of the cover at the same level of the road surface.
Such operation is in fact necessary in order to avoid noticing the presence of the manhole as the vehicle passes over it, with a bothersome sensation for the passengers, possibly provoking damages to the vehicle, if the difference in the level is excessive. Moreover, a difference of level between the manhole and the road surface can be particularly dangerous for bicycles and motorbikes, as it can easily cause the falling of the driver.
In order to avoid such problems, it is generally paid the greatest attention during the manufacturing of the road surface but, in the next re-asphalting, or in case of ground yielding, it is not possible to leave the surface at the same initial level and, therefore, a difference of level between the manhole and the road surface is set up.
If it is desired to set the existing manholes back in level after the next re-asphalting, it is necessary to remove them and to perform a new setting thereof. This operation, although, requires relevant costs, time and labour. In order to solve these drawbacks, manholes provided with height adjusting means have been devised.
Anyhow, these solutions are generally barely practical in their use, expensive and hardly adaptable to the different dimensions and embodiments of the sewage pits.
For example, the European patent application EP 317 189 discloses a manhole comprising a base to be mounted at the mouth of the sewage pit on which a recess is made. The cover of the manhole rests on a frame slidable inside said recess. One or more shims can be interposed between the base and the frame, allowing to adjust the height of the frame and, consequently, the position of the cover with respect to the height of the road surface. However, the manufacturing of this device is complicated and expensive, particularly in the manufacturing of the base on which the frame slides. Moreover, it does not provide any system for the lifting of the frame that, therefore, should be manually lifted by levers or cranes.
Japanese patent application n. JP-A-H10-18328 offers a solution to such problem and discloses a manhole formed by two sliding concentric portions adjustable by means of screws. In this case, the manhole is barely practical in its use since the screws are definitely exposed to the action of the gases coming from the pit and to the draining rain water, that can contain a relevant amount of corrosive agents, mainly salt used in streets during the winter and in marine zones. Similar solutions are offered by EP 1031663 , JP 2001 032306 , JP 2000 027217 , or JP 2002 242213 . More precisely, EP 103166 dicloses an adjustable manhole cover with a lifting part, for providing height/inclination adjusment. The lifting part is formed by a height-adjustable regulating screw which is placed inside the manhole for achieving the adjustment. The device disclosed in JP 2001 032306 , which discloses a kit according to the preamble of claim 1, has an inner frame bearing a cover body and an outer frame capable of being mounted inside the inner frame, Bolts are used for lifting and lowering the inner frame to the outer frame, and a plurality of spacers are provided for adjusting the height of the inner in a specific position. The bolts are interposed between the underside of the inner frame and an inner circumferential shelf section of the outer frame and into which the bolts are inserted.
US patents 4,337,005 and 4,673,310 propose another solution, disclosing a cylindrical pit composed of a resting base and a frame externally concentric thereto. The frame can therefore slide axially with respect to the base, so as to adjust the distance between the two elements. The pit further comprises a set of elastic rings placed externally to the frame. The rings can interpose between the base and the frame by raising the latter, so as to act as shims. Also in this case, the use of complex elements, such as the base and the elastic rings, remarkably affects the costs of the manhole and, consequently, the device is barely advantageous. Moreover, the system for the lifting of the manhole is barely practical and the adjustments thereof become thus long and complex, as the manhole is lifted by a bar extending diametrically at the mouth thereof, the bar being connected to a crane. But, in particular, the manhole cannot be use in squared manholes, since it requires elastic rings that enlarges for behaving as shims as the frame is lifted. Consequently, such feature cannot be performed in squared manholes.
Hence, the technical problem underlying the present invention is to provide a device allowing the adjustment of manholes allowing to overcome the drawbacks mentioned above with reference to the known art.
Such a problem is solved by a kit for the adjustment of manholes for pits according to claim 1 and by the method according to claim 14.
The present invention provides several relevant advantages. The main advantage lies in that it allows practical and easy adjustment of the cover with respect to the level of the road surface, wherein the maintenance costs are remarkably lower than the present ones, although maintaining laying and purchasing costs comparable to the one for traditional manholes.
Moreover, it does not require the setting-up of any element that is easily wearable if placed inside the manhole.
Other advantages, features and the operation modes of the present invention will be made apparent from the following detailed description of a preferred embodiment thereof, given by way of example and without limitative purposes. Reference will be made to the figures of the annexed drawings, wherein:

figure 1 is an exploded perspective view of a kit for the adjustment of manholes according to the present invention;
figure 2 is a rear plan view of a frame of manhole, detail of figure 1;
figure 3A-3C are sectional views along line A-A of the frame of figure 2, according to different perspectives;
figures 4 and 4A are a lateral section along the line B-B of the kit of figure 1 and a respective detail;
figure 5 is a detail according to a perspective view of the kit according the present invention, shown in a section along the line A-A;
figures 6A-6C are sectional views showing the operation of a lifting means of the kit according to the present invention;
figure 7 is an exploded perspective view of a second embodiment of the kit according to the present invention, wherein the lifting means has been removed;
figure 8 is a plan view of the kit of figure 7;
figure 9 is a lateral sectional view along line A-A of the kit according to the second embodiment, provided with closing cover, wherein the lifting means has been removed;
figure 10 is a lateral sectional view along the line B-B of the kit according to the second embodiment; and
figures 11A-11C are sectional views showing the operation of a lifting means of the kit according to the present invention, in the second embodiment thereof.

Referring initially to figure 1, a pit 100 is shown according to an exploded perspective view, on which a manhole frame 4 is laid, analogously to the traditional systems. A cover, not shown in the present figure, is then laid thereon. As it could be appreciated in the following, one advantage of the present invention consists in that it allows the adjustment of manholes without requiring relevant modifications compared to traditional manholes and anyhow allowing the use of conventional covers. This is remarkably important in order to maintain limited manufacturing costs and anyhow comparable to traditional frames.
The frame 4 is arranged resting on an border 101 of the mouth of the pit, interposing one or more shims 3. As it will be seen in the following, the shims 3 allow the adjustment of the manhole or, more precisely, to adjust the height thereof with reference to the road surface 6 or to any other analogous reference. Particularly, the shims 3 are plate-shaped and have such dimensions that openings 46 are defined at the frame corners, when a shim is placed at the a respective frame side, as shown in figure 5.
As it is evident, the more shims are used, the highest the manhole is and, eventually, it will be possible to align the manhole with tilted surfaces by using a different number of shims on each side.
By way of example, it could be used a shim 3 for each side of the manhole during the laying thereof. Then, if the road surface 6 is positioned in an higher position after a re-asphalting of the road, the kit according to the present invention allows to lift the frame 4, according to the method described in the following, and to place further shims 3, until the frame is located at the same level of the road surface 6 or, anyhow, at the desired height.
In particular, with references to figures 2, 5 and 6A-6C, the lifting of the manhole is achieved by suitable spacing means which, in the present embodiment, comprises lifting plates 71, in particular in a number equal to four, said plates having threaded seats 73, wherein a screw 8 can engage, and respective resting plates 72.
Moreover, the frame 4 comprises a rim 42 having holes 44 so as to allow the engagement with play of the screws 8.
The operation of such lifting means is described in figures 6A-6C.
In fact, in order to achieve the lifting of the frame 4, the lifting plate 71 and the resting plate 72 are initially located inside the openings 46, in an intermediate position between the manhole and the pit 100, more precisely below the rim 42.
This arrangement is such that a resting surface 720 of the plate 72 is arranged resting on the border 101 of the pit, whilst a lifting surface 710 is below the rim 42, facing thereto.
Moreover, the plate 71 is located so that the threaded seat 73 is substantially concentric to the hole 44 realized on the rim.
Then, with reference to figure 6B, the screw 8 is engaged in the hole 44 and screwed in the respective threaded seat 73.
Thus, as shown in figure 6C, the plate 71 is vertically lifted by keeping the lifting plate 71 steady and screwing the screw 8 on the seat 73, as the bottom of the screw remain resting on the resting plate 72.
Further screwing the screw, the plate 71 comes into contact with the rim 42 by the lifting surface 710 and thus driving high in vertically direction also the rim 42. This process, i.e., allows to vary the space between the surface 710 and 720, thus achieving the lifting of the frame 4 with respect to the pit 100, onto which said surfaces are respectively resting.
Thus, it is possible to increase the distance between the rim and the frame, so as to place further shims 3 or removing them, in the case they are not necessary anymore.
Moreover, the lifting means also allows to easily remove the frame 4 for maintenance.
After placing the further shims 3, the lifting means could be easily removed, by taking out the screw 8 and removing the plates 71 and 72 from the opening 46. Such system advantageously allows to use said lifting means as the only equipment for the lifting of several manhole, thus obtaining a remarkable saving on the costs than the known manholes provided with adjusting means. Moreover, the only component having threaded parts of the kit according the present invention is the lifting means and their capability of being removed allows to avoid that any threaded part comes into contact with liquids or vapours flowing in the manhole, in such case said part will surely be remarkably subject to wear.
Moreover, the lifting means can be easily operated by a single worker, without the aid of any particular external equipment rather than a key for rotating the screw 8.
It should be also comprised that the plates can be also spaced with different methods, e.g. by a jack-based system or the like.
Moreover, the resting plate 72 could also not be present and, in such case, the resting surface 720 would be defined by the bottom of the screw 8, as, e.g., it happens in the next embodiment.
With reference to figures 2 and 3A-3C, the frame and the other components in general of the kit according to the present invention also have some particular arrangements allowing to perform more effectively the lifting action and, in general, they offer several advantages during the installation and the maintenance.
In fact, the frame 4 has engaging means 47 and 48 for the purpose of making easier the lifting of the resting plate and the lifting plate respectively. Such engaging means 47 and 48 are made by guides wherein the plates can slide, so as to be easily engaged in a suitable position for achieving the lifting. Moreover, the engaging means allows to keep the plates still during the lifting of the frame, which requires the screwing of the screw in the threaded seat 73, thus making the operation even easier.
It should be noted that the plates 71 and 72 have different dimensions, so that it possible to insert by the respective guide 47 the resting plate first, which is wider, and then the lifting plate over the former.
Moreover, the plates 71 and 72 has wedge shaped ends so that they can completely engage at the corners of the frame 4.
With reference than to figure 4A, the frame furthermore has a sloping edge 49 allowing an improved stability to the manhole, without compromising the lifting operations. Once the manhole is installed, the edge 49 will be covered with asphalt, or with any other material used in the ground wherein the manhole is placed, so as to allow enough stability to the frame. Nevertheless, since such edge is sloped, it will be possible to lift the frame without necessarily removing completely the asphalt covering the edge, since it will be broken by the lifting itself. In particular, the manhole can be laid in a single layer of asphalt, whilst being laid below in a second stronger material 60, as shown in figure 4A.
Always with reference to figure 4A, the spacing means 3 has coupling means and, in the present embodiment, it is realized by a projection 31 and a respective coupling seat 35. Accordingly, it will be possible to stack the shims one above the other in a stable arrangement. Moreover, the frame 4 also has an analogous coupling seat 45, wherein a projection 31 can engage.
Furthermore, the use of damping elements 40, whereon the cover is posed, at the sides of the frame 42 is particularly advantageous, as again shown in figure 4A. These damping elements allow to avoid, or at least reduce, the noise during the passing of vehicles over the manhole, a remarkably desired feature in urban centers.
It will be also understood that the present invention is open to several different embodiments alternative to hereto-described ones, some of which will be briefly illustrated hereinafter, with reference only to the aspects differentiating them from the first embodiment considered hereto.
With reference then to figure 7, according to an alternative embodiment, a kit for the adjustment of manhole for pits 100 comprises a substantially flat secondary frame 1, apt to be placed resting at the border of the mouth of the pit 100.
In the present embodiment, the frame 4 has a substantially squared section and it is formed by four side walls 41, developing substantially parallel to an end portion 102 of the frame 100.
Thus, the side walls 41 can define a space apt, in use, to receive at his end portion both the secondary resting frame 1 and the pit 100. Accordingly, the frame 4 can slide with respect to the end portion 102 of the pit and to the secondary frame resting on border 101 thereof.
As in the preceding embodiment, the frame 4 comprises the inside rim 42, developing substantially perpendicular to the above mentioned side walls 41 and, moreover, substantially parallel to the secondary resting frame 1.
As a result, by inserting the frame 4 on the secondary frame 1, the developed surface of the rim 42 is substantially facing to a first side of the latter.
The cover 5 is then placed on the on a second side of the rim 42 so as to achieve the blinding of the pit. It should be also noted that the position of the rim from the upper end of the frame is so that the cover 5, when posed, is substantially at level with the latter, wherein upper end should be intended as the one facing the road surface 6.
As previously disclosed, the rim 42 faces the secondary frame 1 and thus it is possible to interpose at least an angle shim 3 therebetween, allowing to vary the vertical position of the frame 4 with the cover 5, respecting to the pit 100. According to the described embodiments, the shims 3 are some millimeters thick and made of plastic or metallic materials, with enough mechanical strength to be able to bear the stress due to the passage of vehicles over the cover 5.
The use of angle-shaped shims not only allows to vertically adjust the position of the cover, but also to tilt the surface thereof, by using angle shims only at single corner of the secondary frame 1.
Moreover, the use of shims with different thickness can be provided, so that it is possible to easily adjust the vertical position of the frame with the cover, by using combination of different thickness.
More precisely, during the laying of frame and secondary frame of the kit according to the present invention, a first shim is posed at the corner of the secondary frame, thus defining, in use, a spacing between rim 42 and secondary frame 1.
During the laying of the present device it will be therefore possible to make a first lay of the road surface so as that it will be placed at level with the cover 5. During the successive re-asphalting works and if even in the first lay a perfect alignment between road surface 6 and cover surface 5 is not achieved, it is possible to raise the frame 4 and place additional shims, provided that the cover is removed and according to the method hereby described. As a result, the frame 4 and thus also the cover 5 are placed in upper vertical position than the first one.
This operation could be easily repeated during the next re-asphalting, eventually removing the previously placed angle shims, if a layer of asphalt is removed and the level thereof is lower than the preceding one after the road rebuilding.
Always with reference to figure 7, the secondary frame 1 and the frame 1 have at their corners respective holes, aligned therebetween, denoted with the reference numbers 13 and 43.
Also the shims 3 have a hole 32 which, in use, is aligned to the holes 13 and 43 in his turn.
Hence, with reference to figure 9, suitable means for maintaining the alignment between the secondary frame 1, frame 4 and angle shims 3 can be placed.
In the present embodiment, such means is achieved by a pin 9 to be plugged in the three holes 13, 32 and 43. Always according to the present embodiment, the coupling between pin and hole is with play, thus allowing an easy removal thereof.
Accordingly, the pin 9, or any other equal means, will be removed in order to add additional angle shims, thus allowing to place them as previously described.
Always with reference to figure 8, at least an angle shim 3 has coupling means with the rim 42, also in the present embodiment achieved by the seat 45 and the respective projection 31. As a result, the sliding of the angle shim is avoided or, anyhow, making the positioning thereof easier. Such projections are moreover shown in figure 7.
In the present embodiment, the projection 31 is shaped as a spherical cap and the seat is complementary shaped, so that the rim and the angle shim will keep in contact even when the frame is tilted by using a different number of shims at the four corners.
Always for making the laying of the manhole easier, the secondary frame 1 further comprises abutments 11, limiting the displacement thereof above the border 101, as shown in figures 9 and 10.
Finally, as shown in figures 11A-11C, even the present embodiment allows the use of lifting means, hereby realized by the lifting plate 71 and the screw 8, since the resting plate 72 is not required for the presence of the secondary frame.
However, it should be noted that the first embodiment provides the advantage of providing a greater resting surface between the manhole and the pit border, thus allowing to respect more easily the provisions defining the limits in the maximum load bearable by the pit surface.
The present invention has hereto been described with reference to preferred embodiments thereof. It is understood that there might be other embodiments referable to the same inventive kernel, all falling within the protective scope of the claims hereinafter.

Claims

A kit for the adjustment of manholes for pits (100), said kit comprising a frame (4) apt to be placed resting on said pit (100), spacing means (3) of said frame (4) from the pit (100), apt to vary the position of said frame (4) with respect to a reference surface (6), and lifting means (8, 71) of said frame (4), said lifting means (8, 71):
- being re-movably insertable between said frame (4) and said pit (100);

- said lifting means (8, 71) comprises a lifting plate (71) and a screw (8); and

- comprising a lifting surface (710) and a resting surface (720), respectively facing to said frame (4) and resting on a border (101) of the pit (100), the distance between said surfaces (710, 720) being adjustable so as to achieve the lifting of said frame with (4) respect to the pit (100);
wherein said lifting plate (71) has a threaded seat (73), so that the variation of distance between said surfaces (710, 720) takes place by screwing/unscrewing said screw (8) in said threaded seat (73), so as to move said lifting surface (710),
characterized in that openings (46) are defined by said frame (4) when placed over the pit (100), said openings (46) being apt to receive said lifting plate (71), and in that lifting plate (71) can be alternatively located inside said openings (46) for adjusting the manhole, and removed from said openings (46) after the manhole is adjusted.
The kit for the adjustment of manholes for pits (100) according to claim 1, wherein said frame (4) has engaging means (47, 48) said lifting means (8, 71) engaging thereto, such that said plate (71) is vertically lifted by keeping said lifting plate (71) steady by said engaging means (47, 48) and screwing the screw (8) on said threaded seat (73) of said frame (4), so that when said plate (71) comes into contact with a rim (42) of said frame (4) by said lifting surface (710), it drives high in vertical direction said frame (4).
The kit according to the preceding claim, wherein said frame (4) comprises a hole (44) apt house said screw (8) with play.
Kit according to any of claims 1 to 3, wherein said lifting means (8, 71) further comprises a resting plate (72).
Kit according to any of claims 2 or 3 and 4, wherein said engaging means (47, 48) comprises guides (47, 48) apt to receive said plates (71, 72).
Kit according to any of the preceding claims, wherein said spacing means (3) has coupling means (31, 35).
Kit according to any of the preceding claims, wherein said frame (4) has coupling means (45) with said spacing means (3).
Kit according to any of the preceding claims, wherein said spacing means comprises shims (3).
Kit according to any of the preceding claims, wherein said frame (4) has a sloping edge (49).
Kit according to any of the preceding claims, further comprising a secondary resting frame (1), apt to be placed resting on a border (101) of the pit (100) wherein said frame (4) comprises side walls (41) developing substantially parallel to at least an end portion (102) of the pit (100), said side walls (41) being apt to define a space apt to house said secondary resting frame (1) and at least said end portion (102) of the pit (100) so as to allow the sliding of said frame (4) on said end portion (102), said frame (4) further comprising an internal rim (42), said rim (42) being apt to receive said cover (5) resting thereto, and having a substantially parallel development to said secondary frame (1), so that said spacing means can be disposed between said secondary frame (1) and said rim (42).
Kit according to the preceding claim, comprising means apt to maintain the alignment (13, 32, 43, 9) between said spacing means (3) and said frame (4) and/or said secondary frame (1).
Kit according to the preceding claim, wherein said means apt to maintain the alignment (13, 32, 43, 9) comprises seats (13, 32, 43) respectively made on said spacing means (3), said frame (4) and/or said secondary frame (1) and a pin (9) apt to be inserted in said seats (13, 32, 43).
Kit according to any of the preceding claims, wherein said secondary frame (1) comprises shoulders (11), apt to limit the displacements of said secondary frame (1) above said border (101).
Method for the adjustment of manholes for pits (100), comprising the steps of positioning a lifting plate (71) of lifting means (8, 71) between a frame (4) and said pit (100) in openings (46) defined by said frame (4) when placed over the pit (100), so as to place a lifting surface (710) and a resting surface (720) of said lifting means (8,71) respectively facing to said frame (4) and resting on a border (101) of the pit (100); varying the distance between said surfaces (710, 720) so as to achieve the lifting of said frame (4), positioning spacing means (3) between said frame (4) and said pit (100) and varying the distance between said surfaces (710, 720) so as to achieve the lowering of said frame (4) for removing said lifting means (8,71) and then removing said lifting means (8, 71).
Method according to the preceding claim, wherein said step of varying the distance between said surfaces (710, 720) takes place by screwing/unscrewing a screw (8) in a respective threaded seat (73), so as to move said lifting surface (710).