Height adjustable bearing frame for manhole covers

Abstract

 A height adjustable bearing frame for manhole covers, comprises a frame (14) for holding and translating a manhole cover (12) vertically. The frame is provided with a plurality of threaded pins (18) on which nuts (16) are screwed. The nuts (16) are rotatingly carried by the walls (11) of the conduit (10) closed by the manhole cover (12) so as to allow the vertical translation of the manhole cover's bearing frame (14).

Description

[0001] This invention refers to a height adjustable bearing frame for manhole covers.

[0002] Manhole covers are usually inserted in roadway openings and rest upon annular bases made of concrete or other materials that are extremely resistant against heavy loads and that, as well as realizing the supporting bases for the manhole covers, also realize the walls of the drain well.

[0003] It happens frequently that when it is necessary to remake the roadway or to cover it with a new layer of bitumen, the manhole cover has to be raised to a position which is different in height from the original one. In this case it is necessary to make a new supporting base for the manhole cover, adding or removing material that forms the base. These operations for the removal or the integration of material request lots of working hours, and this makes every modification of the manhole cover's base become very expensive for the Public Administration.

[0004] It is a purpose of this invention to propose a vertically movable frame for substaining the manhole cover which can be translated vertically very easily and quickly in relation to the variations of the roadway so that these operations may have extremely limited costs for the Public Administration.

[0005] For these and other purposes that will be better understood later on, this invention proposes to realize a height adjustable bearing frame for manhole covers, characterized in that it comprises a frame for holding and translating the manhole cover vertically, said frame being provided with a plurality of threaded pins on which nuts are screwed; the nuts being rotatingly carried by the walls of the conduit closed by the manhole cover so as to allow the vertical translation of the manhole cover's bearing frame.

[0006] The device according to this invention is now going to be described referring to the enclosed drawings, in which:

fig. 1

is a vertical cross section of the device according to a first embodiment;

fig. 2

is a partial vertical cross section of the device according to a second embodiment.

[0007] In a roadway, drains are realized for discharging water or for other purposes. These drains are usually communicating with the outside through conduits 10 or drain wells having walls 11 normally made of concrete. A manhole cover 12 is usually resting on the extremities of the walls 11 so as to be level to the road's surface.

[0008] According to this invention, between the walls 11 and the manhole cover 12 a frame is inserted, consisting of two separate sections 13 and 14.

[0009] Section 13, which has an L shaped cross section, rests directly on the extremities of walls 11. It is also provided with a plurality of holes 15 in correspondence of which there are respective screw nuts 16 which are carried by section 13 itself.

[0010] Section 14, instead, has a substantially T shaped cross section. The central flange 17 is provided with a plurality of threaded pins 18 that are welded on it and that are meant to be screwed into nuts 16, pass through holes 15 of section 13 and slip into cavities 19 obtained in the walls 11.

[0011] By means of this device the manhole cover 12 will stand on the flanges 17 of T shaped section 14 while the other two flanges of such section, that is the superior flange 20 and the inferior flange 21 will form respectively an element for containing the manhole cover sideways and a guiding element for the vertical translation for the section 14 laterally to the walls 11.

[0012] When the position of the manhole cover 12 has to be raised or lowered, it is enough to screw or unscrew the nuts 16 so that the respective threaded pins 18 move vertically and carry the section 14 that is integral with them.

[0013] The adjustment of the height of the section 14 may have an infinite number of positions, so that the alignment of the manhole cover 12 with respect to the road surface is always guaranteed. It can be understood that this kind of adjustment is extremely easy and quick, and that it will only be necessary to choose adequate dimensions for sections 13 and 14, for pins 18 and for nuts 16 to make the whole structure extremely rigid and reliable, as if the manhole cover was resting directly upon the concrete base that actually consists of the walls 11.

[0014] To avoid any infiltration of dirt that could damage the pins 18, these can be covered by elastic sleeves 22 that prevent them from infiltrations from the outside and avoid the leakage of lubricant grease that is spreaded on the pins 18 and is applied inside the cavities 19 of the walls 11 so to guarantee the correct operation of the device.

[0015] Referring now to fig. 2, a partial cross section shows a variant of the frame that is the object of this invention.

[0016] For simplicity the elements that are common to both embodiments have been indicated with the same reference numbers.

[0017] A screw nut 30 is welded on the inferior surface of the central flange 17 of section 14. A threaded pin 18 is screwed at first into nut 30, then into a second nut 31 and finally into a lock nut 32; these last two nuts grip the superior flange 33 of a C shaped section 34; a through hole 35, in which the threaded pin 18 is inserted, is obtained in flange 33.

[0018] The inferior flange 36 of section 34 stands directly on the basement 37 of the conduit 10. A horizontal flange 38 is welded on the vertical flange 39 of section 34 near said basement sticking out towards the outside of the conduit 10. Such external flange 38 represents the lower limit stop for section 14. The height adjustment of said section is carried out as follows: first of all lock nut 32 has to be unscrewed; then nut 31 has to be tightened or untightened to raise or lower section 14 and consequently the manhole cover 12.

[0019] When the desired position of this is reached, it is necessary to tigthten up lock nut 32 to hold section 14 in position.

[0020] A sleeve 40 is welded to flange 33 to protect pin 18 from any dirt infiltration, as done in a similar way by the elastic sleeves 22 shown in fig. 1.

[0021] The embodiment that has just been described represents an alternative to the frame of fig. 1.

[0022] As a matter of fact, in some cases it is better not to introduce changes to an already finished element, or it may be necessary to build walls of the drain well able to substain exceptionally heavy loads. According to the embodiment in fig. 2, it is possible to realize the walls of the drain well quite cheaply in a second time, that is after positioning the frame.

[0023] This prevents from having to dig cavities for receiving the threaded pins in pre-existing walls.

[0024] When installed, the frame is fitted on top of the basement 37, and the concrete for realizing the walls 41 is casted externally with respect to the frame, with section 14 acting as a formwork. After the concrete setting, the height of section 14 can be adjusted.

[0025] Consequently, the frame is steadily fixed to the new walls of the drain well, as the flange 38 is buried in concrete.

[0026] To cut down the bond between concrete 41 and section 14, the external surfaces of the latter may be previously spreaded with grease before casting the concrete.

Claims

1. A height adjustable bearing frame for manhole covers, characterized in that it comprises a frame (14) for holding and translating the manhole cover (12) vertically, said frame being provided with a plurality of threaded pins (18) on which nuts (16) are screwed; the nuts (16) being rotatingly carried by the walls (11) of the conduit (10) closed by the manhole cover (12) so as to allow the vertical translation of the manhole cover's bearing frame (14).

2. A frame according to claim 1 wherein the threaded pins (18) are welded at the bottom of the frame (14) and the nuts (16) rest on the top of the walls (11) of the conduit (10); the pins (18) being slipped into cavities (19) obtained in the walls (11) of the conduit (10).

3. A frame according to claim 2 wherein the nuts (16) rest on top of a second L shaped frame (13) that is fixed onto the the superior edges and on the outside wall of the conduit (10).

4. A frame according to claim 1 wherein the frame (14) has a T shaped cross section, two flanges (17, 20) of which act as bearing elements and side containing elements for the manhole cover (12); a third flange (21), being an extension of the side containing flange (20) on the other side of the bearing flange (17) and acting as a guiding element for the frame (14) along the outside of the walls (11) of the conduit (10).

5. A frame according to claim 1 wherein the pins (18) are screwed on the bottom of a movable frame (14) and are fixed by means of nuts (31,32) to a second frame (34) resting on the basement (37) of the conduit (10).

6. A frame according to claim 5 wherein the second frame (34) has a C shaped cross section.

7. A frame according to claims 1 and 5 wherein the movable frame (14) has a T shaped cross section, two flanges (17, 20) of which act as bearing elements and side containing elements for the manhole cover (12); a third flange (21) being an extension of the bearing flange (17) and acting as a guiding element for the frame (14) along the inside of the walls (11) of the conduit (10).

8. A frame according to claims 1 and 5 wherein the walls (11) of the conduit are casted after the installlation of the frame (14, 34), the external surfaces of which act as formworks for the walls (11) of the conduit (10).

9. A frame according to claims 2 and 5 wherein sleeves (22, 40) are slipped onto the threaded pins (18), said sleeves containing lubricant grease.

Drawing