ES2297890T3 - FRAMEWORK FOR THE COVER OF AN INSPECTION MOUTH. - Google Patents

Abstract

A frame (20) for holding a lid of an inspection mouth (22); the frame (20) comprising a vertical peripheral wall (28); support means (40; 42) extending inwardly from at least part of the wall (23) to support an inspection manhole cover (22); and an external flange (30) extending outwardly from a lower part of the wall (23) to anchor the frame to the floor; characterized in that the external flange (30) has placed on a top surface in use, a plurality of rods (44; 55) to improve the anchoring of the flange (30) and reinforce the frame (20) against bending, having the frame (20) one or more corners (26), the rods (44, 50) being in or adjacent to the corner (s) (26) of the frame (20).

Description

Frame for the cover of a mouth of inspection.

This invention relates to a framework for hold the lid of an inspection mouth and the combination of frame and cover of the inspection mouth.

Inspection manhole covers are known from many years ago and initial examples of such tapas are presented in United Kingdom Patents Nos. 27088, of the year 1910, and 4221, of the same year, both under the name of Samuel Henry Adams, and in the Documents cited in them. Adams manhole covers they generally use circular frames that have flaps or flanges curved or inclined around the upper end of the frame, the inclined flanges having the objective of presenting a inclined surface instead of an abrupt edge, since the road material around the inspection mouth is erodes during use. The flanges are provided with a set of holes or rods, or other protrusions to contribute to the anchoring of the frame on the road surface and for increase the durability of the road surface in the The frame is anchored.

The "Chieftain" range of caps constitutes the most recent example of inspection manhole covers produced and sold by the present applicants.

Additional examples of manhole covers inspection and its frames are presented in GB A-162 434, GB A-080 373, GB A-2 291 452, GB A-2 299 603 and US 5 240 346, US 664 152 A and US 24 454-A.

Despite the fact that the mouth covers of inspection are known and have been used for a long time, the experience has shown that a large number of mouth units installed inspection fail in service due in large fault measurement of the foundation material (e.g. mortar) that anchor the frame of the inspection mouth unit in place. Remains understood that more than 200 million pounds are invested annually only in the UK to replace such units that have failed and it will be appreciated therefore that the contribution of a unit of manhole cover that can be firmly anchored in your site and remain anchored even under heavy traffic loads, It represents a substantial problem.

The research developed by applicants shows that the failure in the mouth units of Inspection can be attributed to a number of factors. It has been shown for example that the bending of the corners of the frames of inspection mouths under traffic loads, causes an increase in level of effort on the foundation mortar used to anchor the frames in place and is the main cause of failure of the mortar. Another significant cause of foundation failure based on mortar resides in the severity of the forces created by the vehicles that brake on the manhole inspection units, causing the movement of the entire unit (frame and cover) in the Direction of vehicle movement. In general, the applicants have found that inspection mouth units experience significant stress efforts under loads of normal traffic and that these efforts exceed the capabilities of normal cement mortars.

It is the object of the present invention to provide a manhole inspection unit and in particular a manhole frame of inspection that has a greater capacity to resist efforts voltage created by traffic loads and in particular capable of being anchored in place more firmly.

It has been discovered that placing a reinforcement, such as linkages in the corners of the inspection mouth frame, rigidity and resistance to flexion, and that this greatly increases the capacity of the unit to resist mortar failures once installed. Too it has been discovered that the increase in contact surface cement-metal provided by the linkage increases substantially the tensile load resistance and improves the foundation strength of the mouth frame of inspection.

Correspondingly, in a first aspect, the invention provides a frame for holding a manhole cover inspection; the frame comprises a peripheral vertical wall; support means extending inward from at least part from the wall to hold a lid of the inspection mouth; and one external flange extending outward from a bottom from the wall to anchor the frame on the floor; characterized because the external flange has placed on a surface superior in use, a plurality of rods to improve anchoring of the flange and reinforce the frame against bending, taking the frame one or more corners, the rods being at or adjacent to the corner (s) of the frame.

The frame can be of any configuration or size and can for example be circular or non-circular in shape. Preferably, the frame is rectangular.

The plurality of elongated rods serves to increase the rigidity of the frame and increase its resistance to flexion. The presence of such reinforcement projections in the corners of the framework is of particular importance in the case frames rectangular. The projections (e.g. rods) may be present in or adjacent to the corners of the frame. Preferably without However, they are present only in the regions of the corners of the frame. The rods are preferably substantially parallel. and at least the center of said set of rods can be oriented towards the center of the frame. For example, when the frame is rectangular, the rods can be aligned in one direction diagonal with respect to the corners of the frame.

The outer flange of the frame preferably has a plurality of wider regions interspersed with a plurality of narrower regions. When the frame for example is rectangular, the widest regions of the external flange are placed in the corners of the frame, therefore serve to reinforce further the frame against flexion. This is important because the Load tends to concentrate on the corners of the frame. Typically, at least the surfaces of the widest regions of the flange external have a plurality of projections (e.g. rods elongated) placed there.

It has also been seen that the perforations of injection present in the frames of the mouth units of known inspection, which are intended to act as anchoring means of the frame to the foundation mortar, really increase the tension inside the mortar. Therefore, it is preferred that the frame does not contain such injection perforations or, if are present, which are located far from the corners.

In another aspect, the invention provides a set of manhole cover consisting of a frame such as define here and an inspection manhole cover configured so such that it can be held in a seat determined by the wall peripheral and support means.

The invention also provides an installation of an inspection mouth comprising an inspection mouth that it has a layer of foundation material surrounding the mouth of access to it, a framework as already defined based on the foundation material, with the outer flange covered completely by the foundation material; and a mouth cover of Removable inspection mounted on the frame.

The foundation material can be by example, a mortar or a combination of mortar and material filler such as asphalt or similar materials. External flange it can be completely surrounded by the mortar or it can be fixed inside a mortar layer and a layer of filler material Compact on top of the flange.

The invention will now be illustrated by reference. to the specific embodiments shown in the diagrams that are accompany, although not limited to them, in which:

Figure 1a is a plan view of one type known frame of inspection manhole cover;

Figure 1b is a sectional elevation along line 1-1 of Figure 1a;

Figure 2 is a plan view of a unit inspection mouth comprising a lid and a mouth frame of inspection in correspondence with an embodiment of the invention;

Figure 3 is a fragmented view showing one corner of the frame of the manhole inspection unit of the Figure 2

Figure 4 is a fragmented view showing a corner of the frame of an inspection mouth unit in correspondence with another embodiment of the invention; Y

Figure 5 is a sectioned elevation schematic illustrating a portion of the mouth unit of inspection of the invention, embedded in the mortar.

With reference now to the diagrams, the Figures 1a and 1b illustrate a known type of cover frame of a inspection mouth 2 rectangular. Frame 2 comprises a vertical peripheral wall 4 whose lower end extends an external flange 6 that is of substantially uniform width. The external flange 6 has a relatively low upward edge 8 in its outermost part and has a number of reinforced elements 10 that join the edge 8 with the vertical peripheral wall 4 to provide reinforcement To provide the support means of a cover an inspection mouth (not shown) in Figures 1a and 1b, is extend internal flanges 14 and 18 that partially surround the side internal wall 4.

The frames of the type shown in Figures 1a and 1b in practice can be placed in a mortar foundation that surrounds an inspection mouth such that the external flange 6 is completely contained within the mortar or that the flange rest in a mortar layer and a layer of filler material such as asphalt that compacts on top of the flange. A set of eight elongated holes 12, known as perforations of injection, they are spaced around the outer flange 6, being its function provide a means of anchoring the flange within the mortar foundation surrounding it to keep the frame in its site.

Research has shown that frames of the type shown in Figures 1a and 1b can be released from the layer anchor mortar as a result of tensions and efforts caused by vehicle loads on the manhole unit of inspection and particularly stress efforts caused by vehicles that brake on the manhole inspection unit. Although the stress efforts are not particularly high, the Mortar materials have low tensile strength and by both the efforts related to the strength of the material are significant. The flexion of the corners of the frame under the forces imposed by vehicles crossing over the unit of inspection mouth leads to increased levels of fatigue inside of the mortar and finally make the mortar detach from the external flange The problem is exacerbated instead of relieved due to to injection perforations 12.

Figures 2 through 5 illustrate improved frames of manhole covers in correspondence with the invention. As shown in Figure 2, the inspection mouth assembly It comprises a frame 20 and a pair of inspection mouth covers 22 They are generally triangular. The keyways 24 are placed on each cover 22 to hook them with an uncovering tool the covers.

The frame 20 is rectangular in shape and has four corners 26. The frame comprises a vertical peripheral wall  28, whose bottom edge extends a flange 30 outwards. The flange 30 has wider portions 32 at corners 26 and narrower portions 24 between the corners. At intervals spaced reinforcing elements 36, 38 extend around the perimeter of the flange between flange 30 and wall 28 for provide reinforcement

The legs 40, 42 extend into the peripheral wall 28 to hold the covers 22. The legs can be ribbed and can cover the inside corners of the wall 28, as shown in Figure 4, or they can be non-ribbed and of a generally uniform width, as shown in Figure 3. Without however it should be noted that the legs to hold the covers of inspection mouths do not necessarily have to have configurations shown, but may adopt a different variety of different configurations.

In each of the corners of the frame, the wider portions 32 of the flange are reinforced by a set of aligned and substantially parallel rods 44 oriented generally in diagonal direction. The rods 44 They perform several functions. First they serve to reinforce the corners providing a reinforcing effect to improve the frame resistance to bending and distortion under the weight of the Traffic on the road. Second, the rods increase the surface area over which the flange is in contact with the mortar 46 (or a combination of mortar and filler material) into which the frame in use is inserted. This last effect is shows more clearly in Figure 5. It may be noted that in the Figure 5 flange 30 is shown fully embedded in the mortar of the foundation. However alternatively, the flange could be placed inside a layer of mortar and a layer of material filler such as compacted asphalt above the surface of the flange as indicated above.

The rods 44 therefore allow retention of the bridle more securely in the mortar and this implies that the frame has greater capacity to resist forces (represented by the double arrows D in Figure 5) created by the vehicles which brake on the manhole covers 22.

It can also be noted that flange 30 lacks the injection perforations of the well-known mouth frame of inspection shown in Figures 1a and 1b and the absence of these injection perforations eliminates another source of tension on the mortar 46.

In the embodiment shown in Figures 2, 3 and 5, the rods 44 are shaped as protrusions that rise on the upper surface of the flange. In another presentation (which not part of the claimed invention), as shown in the Figure 4, the rods can be delimited by a series of elongated recesses 48, delimiting the rods surfaces 50 of the flange between recesses 48. This embodiment shares with the embodiment of Figures 2, 3 and 5 the advantage of better bonding from the frame to the foundation mortar but is as reinforced as the embodiment of Figures 2, 3 and 5 and for this reason it is less preferable.

It is easily evidenced that they can be done numerous alterations and modifications to the frames for covers of inspection mouth illustrated in the accompanying diagrams without depart from the scope of the appended claims.

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References cited in the description

This list of references cited by the applicant is only for the convenience of the reader. It is not part of the European Patent document. Although special care has been taken in the compilation of references, errors or omissions cannot be excluded and the EPO denies any responsibility in this regard .

GB 27 088 TO

GB 2 299 603 A

GB 1 162 434 TO

US 5 240 346 A

GB 2 080 373 TO

GB 6 641 52 A

GB 2 291 452 TO

GB 2 4454 A

Claims (11)

1. A frame (20) for holding a lid of an inspection mouth (22); the frame (20) comprising a vertical peripheral wall (28); support means (40; 42) extending inwardly from at least part of the wall (23) to support an inspection manhole cover (22); and an external flange (30) extending outwardly from a lower part of the wall (23) to anchor the frame to the floor; characterized in that the external flange (30) has placed on a top surface in use, a plurality of rods (44; 55) to improve the anchoring of the flange (30) and reinforce the frame (20) against bending, the frame having (20) one or more corners (26), the rods (44, 50) being in or adjacent to the corner (s) (26) of the frame (20). 2. A framework in correspondence with the Claim 1 wherein the external flange is provided with a plurality of wider areas (32, 34) spaced one of the others around the periphery of the flange by zones intermediate widths, having each of the wide areas a plurality of rods (44; 50). 3. A framework in correspondence with the Claim 2 wherein the rods (44; 50) determine a plurality of substantially parallel elongated rods (44; fifty). 4. A framework in correspondence with the Claim 3, wherein a central rod of a plurality of  rods (44; 50) is oriented towards the center of the frame (twenty). 5. A framework in correspondence with any of the preceding claims wherein the peripheral wall Vertical (28) has one or more corners (26). 6. A framework in correspondence with the Claim 5 wherein the vertical peripheral wall (28) has rectangle shape 7. A framework in correspondence with the Claim 6 wherein each corner (26) of the rectangle has of a set of said substantially parallel rods (44; 50) diagonally oriented. 8. A framework in correspondence with the Claim 2 or any of the preceding claims dependent on it in which the wide areas (32) of the external flange (30) are placed in the corners (26) of the framework. 9. A framework in correspondence with any of the preceding claims wherein the external flange (30) in The vicinity of the corners is substantially free of injection perforations 10. An inspection manhole cover assembly comprising a frame (20) as defined in any of the preceding claims and an inspection manhole cover (22) configured to be held in a seat determined by the peripheral wall (28) and the support means (40; 42). 11. An inspection manhole installation that comprises an inspection mouth with a layer of surrounding mortar the mouth thereof, a frame (20) as defined in any of Claims 1 to 9, placed inside the mortar, whose External flange (28) is substantially and completely covered by the mortar; and a cover of a removable inspection mouth (22), placed on the frame.