ACTIVE SEALING MANHOLE COVER FOR VAPOR AND LIQUID ISOLATION

Abstract

The embodiments disclosed herein relate to a method for sealing a manhole against emissions, wherein the manhole defines an interior surface, and having the steps of: inserting a manhole cover into the manhole, wherein the manhole cover comprises a top plate and a bottom plate and wherein the manhole cover further comprises a first seal ring in a first annular cavity defined in an exterior surface of the manhole cover and a second seal ring in a second annular cavity defined in the exterior surface of the manhole cover; compressing the top plate and the bottom plate together; decreasing the first annular cavity; and engaging the first seal ring and the second seal ring against the interior surface of the manhole.

Description

BACKGROUND

Technical Field

The subject matter generally relates to the sealing of manholes against vapors and emissions, in particular benzene.

Manholes are connected to systems which can often contain concentrations of toxic and/or harmful gas and vapor emissions. Accordingly, adequate sealing at the manhole is needed to prevent the escape or leakage of said emissions into the atmosphere. Manhole sealing has a variety of unique challenges, including construction and design within a limited space. Conventional or existing manhole sealing has often been insufficient, resulting in rogue emissions and the potential for environmental damage. This conventional technology usually includes a manhole cover having only a single seal around the cover and a multitude of bolts having washers on top of the bolts. The single seal is usually constructed of neoprene or urethane material and has a profile with teeth. The conventional technology frequently results nonuniform compression of the urethane or neoprene seal, thus resulting in gas and vapor leaks. Moreover, aromatic compounds, like benzene will degrade urethane and neoprene material over time, which further contributes to the amount of rogue emissions into the atmosphere. Failure to mitigate benzene emissions appropriately can result in hefty fines for manhole operators.

Accordingly, a need exists for an improved manhole sealing method and apparatus which includes a uniform, consistent, and long lasting seal around the manhole cover, and does not degrade when in contact with benzene emissions.

BRIEF SUMMARY

The embodiments disclosed herein relate to a method for sealing a manhole against emissions, wherein the manhole defines an interior surface, and having the steps of: inserting a manhole cover into the manhole, wherein the manhole cover comprises a top plate and a bottom plate and wherein the manhole cover further comprises a first seal ring in a first annular cavity defined in an exterior surface of the manhole cover and a second seal ring in a second annular cavity defined in the exterior surface of the manhole cover; compressing the top plate and the bottom plate together; decreasing the first annular cavity; and engaging the first seal ring and the second seal ring against the interior surface of the manhole.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. These drawings are used to illustrate only typical embodiments of this disclosure, and are not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic in the interest of clarity and conciseness.

FIG. 1 depicts a front isometric cross section view of an exemplary embodiment of an active sealing manhole cover assembly in an active state.

FIG. 2 depicts a top isometric view of an exemplary embodiment of an active sealing manhole cover assembly.

FIG. 3 depicts a bottom isometric view of an exemplary embodiment of an active sealing manhole cover assembly.

FIG. 4 depicts a cross section side view of an exemplary embodiment of an active sealing manhole cover assembly in a free state.

FIG. 5 depicts an enlarged partial cross section side view of an active sealing manhole cover assembly in a free state.

FIG. 6 depicts an enlarged partial side cross section view of an active sealing manhole cover assembly in an active state.

FIG. 7 depicts an alternative exemplary embodiment of the active sealing manhole cover assembly with sealant port bolt.

FIG. 8 depicts a front cross section view of an alternative exemplary embodiment of the active sealing manhole cover assembly in a free or inactive position.

FIG. 9 depicts an enlarged front cross section view of an alternative exemplary embodiment of the active sealing manhole cover assembly.

FIG. 10 depicts a top perspective view of an alternative exemplary embodiment of the active sealing manhole cover assembly.

FIG. 11 depicts a top perspective view of an alternative exemplary embodiment of the active sealing manhole cover assembly.

FIG. 12 depicts a front cross section view of an alternative exemplary embodiment of the active sealing manhole cover assembly in an active or partially active position.

FIG. 13 depicts an enlarged front cross section view of an alternative exemplary embodiment of the active sealing manhole cover assembly.

FIG. 14 depicts a front cross section view of an alternative exemplary embodiment of the active sealing manhole cover assembly.

FIG. 15 depicts a front cross section view of an alternative exemplary embodiment of an active sealing manhole cover assembly with three plates for a manhole having a straight bore.

FIG. 16 depicts a front cross section view of an alternative exemplary embodiment of an active sealing manhole cover assembly with one plate for a manhole.

DETAILED DESCRIPTION OF THE EMBODIMENT(S) SHOWN

The description that follows includes exemplary apparatus, methods, techniques, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details.

FIG. 1 depicts a front isometric cross section view of an exemplary embodiment of an active sealing manhole cover or manhole cover assembly 10 in an active state 92. FIG. 4 depicts a cross section side view of an exemplary embodiment of an active sealing manhole cover assembly 10 in a free or inactive state 90. The manhole cover assembly 10, when activated or in an active state 92, seals the top or collar 12 of a manhole 11, wherein the manhole 11 has a substantially cylindrical or ring shape. The inner diameter or interior surface 13 of the top or collar 12 may be wider than the inner diameter or interior surface 13 of a body or frame 11a of the manhole 11. A shoulder or shoulder surface 14 joins or connects the interior surface 13 of the collar to the interior surface 13 of the manhole body or frame 11a. Conventional locations for bolt or fastener openings 17 may be defined through the shoulder 14, or through the manhole 11.

The manhole cover assembly 10 defines a top end 15 and a bottom end 16 (as shown in FIGS. 2 and 3 respectively, and includes three plates 20—a top plate 30, one or more central, center, or middle plate 40, and a bottom plate 50. While the exemplary embodiments as depicted in FIGS. 1-6 show at least three plates 20, one plate 20, two plates 20 or additional plates 20 beyond three plates 20 are considered within the scope of the disclosure. Further, the manhole cover assembly 10 may further include the manhole 11 itself in certain alternative exemplary embodiments. Each plate 20 may be interconnected or complementary to one another when assembled or stacked together, whereby each plate 20 defines the elevated surfaces and/or recessed surfaces into which the corresponding elevated surfaces may connect or join to as appropriate into the corresponding recessed surfaces and as further described below, when assembled as the manhole cover 10.

Each plate 20 also defines a number of plate holes or openings 21 for bolts or fasteners 80 to be inserted therethrough. By way of example only, and not to be limited to same, each plate 20 may have six (6) plate holes or openings 21 defined through each plate 20, adjacent to the edge or perimeter 26 of each plate 20 and evenly distributed about the edge or perimeter 26 of each plate 20, and are aligned with each of the openings 17 as defined in shoulder 13 of the manhole 11.

Additionally, each of the plates 20 defines a profile at the edge, circumference, rim or perimeter 26 of the plate 20. The top plate 30 defines a profile 35 at the circumference, edge or rim 26 of top plate 30; the middle or central plate 40 defines a profile 45 at the circumference, edge or rim 26 of the middle or central plate 40; and the bottom plate 50 defines a profile 55 at the circumference, edge or rim 26 of the bottom plate 50 (see e.g. the detailed or enlarged views as shown in FIGS. 5 & 6). Together, the profiles 35, 45 and 55 of the assembled plates 30, 40 and 50 define an outer surface profile or exterior surface 23 which encompasses the circumferences of the manhole cover 10. The outer surface profile or exterior surface 23 of the assembled plates 20 (including top plate 30, central plate 40, and bottom plate 50) as combined or installed against the interior surface 13 of top 12 of the manhole 11 define at least two annular cavities 22 having a triangular profile 25 which encircle the assembled plates 30, 40 and 50. The triangular profile 25 of each annular cavity 22 can be formed between each pair of adjacent or consecutive plates 20 (i.e. there is a first triangular profile 25 and annular cavity 22 defined on the exterior surface 23 between the top plate 30 and the middle plate 40, and a second triangular profile 25 and annular cavity 22 defined on the exterior surface 23 between the middle plate 40 and the bottom plate 50). There may be additional annular cavities 22 defined on the exterior surface 23 if additional plates 20 are installed. The annular cavities 22 are a larger size when in the free or inactive state 90 of the manhole cover assembly 10, and a smaller size when in the active state 92 of the manhole cover assembly 10. In alternative exemplary embodiments, other profile shapes for the annular cavity 22 may be used, such as and not to be limited to: a square profile which can be used to flatten the O-rings 60, making the O-rings 60 to bulge into an oval shape. In addition to a round or circular cross section as depicted in the figures, the O-rings or seals 60 themselves may have, in alternative exemplary embodiments in cross section: a rectangular shape, a triangular shape, a cross or ‘x’ shape, a cup seal shape, or other custom shape, including O-rings or seals 60 with multiple sealing edges.

The top plate 30 may be constructed of a variety of materials, and may optionally be coated. The middle or central plate(s) 40 and the bottom plate 50 may be, in an exemplary embodiment, constructed from aluminum material; however other materials which are naturally corrosion resistant, or that can be plated, anodized, coated, or painted, and as known to one of ordinary skill in the art is encompassed within this disclosure.

A ring, seal, or O-ring 60 constructed of flexible, compressible, or elastomeric material is inserted into each of the annular cavities 22. By way of example only, one such material for the O-ring 60 is the VITON™ branded fluoropolymer elastomer material or fluorinated hydrocarbon rubber product as commercially available from THE CHEMOURS COMPANY. Other flexible, compressible or elastomeric materials which can withstand degradation by benzene or other manhole vapors may be used for the O-ring 60 as understood by one of ordinary skill in the art.

FIGS. 5 and 6 depict an exemplary embodiment of the manhole cover assembly 10 in a free state 90 and an active state 92, respectively, and provide enlarged side cross section views of one side of the manhole cover assembly 10. Each of the top plate 30, the middle plate 40 and the bottom plate 50 of the manhole cover assembly 10 has a substantially disk-like shape or form and includes an extension or augment 31, 41, and 51, respectively, which is at the edge of or surrounds or encompasses the circumference or perimeter 26 about each plate 30, 40, and 50. The extension 31 of the top plate 30 defines an angled, chamfered or beveled surface or chamfer 32 which faces the bottom 16 of the manhole cover 10. The extension 41 of the middle or central plate 40 defines a first angled, chamfered or beveled surface or chamfer 42a facing the top 15 of the manhole cover 10, and a second angled, chamfered or beveled surface or chamfer 42b facing the bottom 16 of the manhole cover 10. Finally, the extension 51 of the bottom plate 50 defines an angled, chamfered or beveled surface or chamfer 52 which faces the top 15 of the manhole cover 10. These angled, chamfered or beveled surfaces or chamfers 32, 42a, 42b, and 52 together with the interior surface 13 of the top 12 of the manhole 11, form or define the triangle profiles 25 of the annular cavities 22.

Additionally the top plate 30 defines a recessed surface 33 at the bottom of the top plate 30. The middle or central plate 40 defines an elevated surface 43a at the top of the middle or central plate 40, and a recessed surface 43b at the bottom of the middle or central plate 40. The bottom plate 50 defines an elevated surface 53 at the top of the bottom plate 50. When assembled, the elevated surface 43a of the middle or central plate 40 connects, fits, engages, or inserts complementarily into the recess or recessed surface 33 of the top plate 30, and elevated surface 53 of the bottom plate 50 connects, fits, engages, or inserts complementarily into the recess or recessed surface 43b of the middle or central plate 40.

When assembled, the plates 30, 40, and 50 have a space or distance 24 between each plate 30, 40, and 50 that decreases as the manhole cover assembly 10 is activated into the active state 92. When the manhole cover assembly 10 is deactivated, inactive, or in a free state 90, the distance 24 between each plate 30, 40, and 50 increases.

A number of bolts or fasteners 80 are inserted at equal distance from each other into the aligned plate holes or openings 21 of each of the plates 30, 40, and 50, and into the bolt hole openings 17. Each bolt 80 defines at least three channels or slots 81 on the body of the bolt 80, into which three bolt O-rings 82 are inserted. Each of the bolt O-rings 82 will contact or engage one of the plates 30, 40, and 50 when in the activated state 92 of the manhole cover assembly 10, as seen in FIG. 6. These bolt O-rings 82 may also be constructed of fluorocarbon-based fluoroelastomer (FKM), such as the VITON™ branded material to be resistant or survive against benzene. Additional channels or slots 81 and bolt O-rings 82 can be present if additional central plates 40 are included in the manhole cover assembly 10. Further, each bolt 80 may have a Belleville washer or conical spring washer 70 around the bolt 80, at each space 24 between the plates 20. By way of example only, each bolt 80 may have a Belleville washer 70 between the top plate 30 and the middle or central plate 40, and a Belleville washer 70 between the middle or central plate 40 and the bottom plate 50. The Belleville washers 70 are flattened in the active state 92 (or relatively more flattened when compared to the free state 90) of the manhole cover assembly 10, and the Belleville washers 70 provide lift, separation, or spring between each of the plates 30, 40, and 50 in the inactive or free state 90 of the manhole cover assembly 10. In alternative exemplary embodiments, the Belleville washers 70 may be omitted from the manhole cover assembly 10.

The manhole cover assembly 10 is inserted into the top or collar 12 of the manhole 11 while in the free or inactive state 90. The free or inactive state 90 is depicted in FIGS. 4 and 5. The bottom plate 50 is in contact with or rests against the shoulder 14 of the manhole 11. One end of the bolts or fasteners 80 may be slightly inserted into the bolt openings 17 of the manhole 11 while in the free state 90, and/or the bolt openings 17 may be aligned with the plate bolt holes 21 of each of the plates 20. Each Belleville washer 70 may be slightly compressed or not at all compressed in the free state 90. The O-rings 60 are not in contact with the interior surface 13 of the manhole top or collar 12.

When the operator desires to seal the manhole 11, the manhole cover assembly 10 is then activated by torquing the bolts 80 into the plates 30, 40, and 50, and the manhole 11 through each of the plate bolt holes 21 and the bolt openings 17 in shoulder 14 of the manhole 11. As the end of the bolts or fasteners 80 are inserted deeper into the bolt openings 17, the plates 30, 40, and 50 compress and draw towards each other and the space 24 between each of the plates 30, 40, and 50 decrease accordingly. The Belleville washers 70 become increasingly flattened as the activated state 92 is achieved. Importantly the angled surface or chamfer 32 approaches or closes toward the angled surface or chamfer 42a, and the angled surface or chamfer 42b approaches or closes toward the angled surface or chamfer 52, thus decreasing the size annular cavity 22. The O-rings 60 are compressed and pushed by the angled and chamfered surfaces 32, 42a, 42b, and 52 closing towards each other and the O-rings 60 are actively pressed towards the interior surface 13 of the top 12 of the manhole 11. When in the fully activated or active state 92, the O-rings 60 fully and sufficiently engage against the interior surface 13 and provides multiple seals around the manhole cover assembly 10, between the interior surface 13 of the manhole 11 and each O-ring 60, and prevent any rogue emissions or leaks of vapor, including benzene and the like, out of the manhole 11. In the depicted exemplary embodiments, the O-rings 60 provide two circular seals around the manhole cover assembly 10; if using additional plates 20, such as additional central or middle plates 40, the improved manhole cover assembly 10 can, via additional O-rings 60, provide additional seals to further increase the redundancy and sealing capability against emissions or vapors such as benzene. The manhole cover 10 would have one less O-ring 60 per number of plates 20 used (such as, in an alternate exemplary embodiment of the manhole cover 10 having four plates 20, such alternate exemplary embodiment would include three O-rings 60; or for an alternative exemplary embodiment of the active sealing manhole cover 10 having five plates 20, such would have four O-rings 60, and so on).

In the alternative exemplary embodiment as shown in FIG. 7, the manhole cover assembly 10 may include or define a port 83 for a sensor 84, such as either a micro pressure gauge, pressure transmitter and/or pressure transducer ported to between the two O-rings 60, to be able to charge and monitor the pressure between the seals 60 to insure the sealing is active. In these alternative exemplary embodiments, either a bolt or fastener 80 may be modified for a cross drilled hole 83, or optionally instead, the middle plates 40 may have a drilled port 83 to provide passage to the instrument or sensor 84. This would allow a pressure to be applied between the two seals 60 either as the decrease in volume as the plates 20 are placed together or by charging through something like a tire Schrader valve. The sensor 84 monitoring could be built in or monitored by sampling with a tire like pressure gauge or basketball like needle similar to those used in the natural gas industry manufactured by PETERSON or PETES commercially available plugs. The ports 83, as defined through bolts 80 or any of the plates 20, may also allow a liquid or paste sealant 85 to be injected if desired to enhance the sealing capabilities of the manhole cover 10, in addition to monitoring or sensing capabilities provided by the sensor 84. A quantity of sealant 85 may optionally be injected into the ports 83 to fill or partially fill into the annulus, annular space or area 86 during the process of activating the manhole cover 10. One annular space 86 may optionally bounded by the O-rings or seals 60 at the top and bottom, the exterior surface of the manhole cover 10, and the interior surface 13 of the manhole 11, although sealant 86 may be injected above or below seals 60 as well (see e.g. FIGS. 7 and 16). Some of these ports 83 also act as a vent to allow the sealant 85 to fill the full annular cavity 22 area. The sealant 85 may be polytetrafluoroethylene (PTFE) based, epoxy based or, alternatively, may be other sealants 85 compatible with their process fluids and gasses. In certain exemplary embodiments, the sealant 85 may be one that is mixed and cures or one that always stays as a thick liquid. In further alternative exemplary embodiments, the sealant 85 may optionally stay liquid until the sealant 85 is exposed to air.

When the operator desires to unseal the manhole 11 and to remove the cover assembly 10, the bolts 80 can rotated or torqued in the opposite direction. As the end of the bolts 80 reverse out of the bolt holes 17, the compression forces on the plates 30, 40, and 50 is relieved. The sealing rings 60 retract or disengage from the interior surface 13 of the top 12 of the manhole 11 as the annular cavities 22 and triangular profiles 25 of same increase in size. The space or distance 24 between each plate 30, 40, and 50 also increases as the compression is released. The Belleville or conical spring washers 70 aid in separating or lifting the top plate 30 from the middle plate 40, and the middle plate 40 from the bottom plate 50 as well. Once all of the sealing rings 60 are disengaged from the interior surface 13 of the top 12 of the manhole 11, the manhole cover assembly 10 can be safely removed.

FIGS. 8-14 depict alternative exemplary embodiments of the manhole cover or manhole cover assembly 10. In the alternative exemplary embodiments as depicted in FIGS. 8-14, the manhole cover 10 may further include a secondary or enhanced means of compressing the plates 20 via the arm or toggle assembly 110, in addition to or beyond the compression of the plates 20 provided by the bolts 80. The arm or toggle assembly 110 includes at least the arm or toggle 100, a hinge 104, an arm or toggle bolt or screw 105, and a coupler 108 which connects the arm 100 to the screw 105. In certain alternative exemplary embodiments, the arm or toggle assembly 110 may be used alone to sufficiently compress, seal, or activate the plates 20 without torquing or using the bolts 80 around the edge or perimeter 26.

The manhole cover assembly 110 may include one or more arm or toggle assemblies 110, wherein each arm assembly 110 may have one arm or toggle 100. As can be seen in the exemplary embodiment in FIGS. 10-11, the manhole cover 10 may have, in certain exemplary embodiments, and not to be limited to such, three arms or toggles 100 placed equidistant from each other about the circumference or edge 26 of the manhole cover 10. Each arm 100 defines a free end 101 and a hinged end 103. The hinged end 103 is connected to a hinge or pivot 104 at the bottom 16 surface of the plates 20 of the manhole cover 10. An arm or toggle threaded fastener, bolt, or screw 105 may be inserted through the plates 20 and is connected to the arm 100 via a coupler 108. The ends of the coupler 108 may be inserted into slots 109 as defined in the arms 100. As the arm bolt 105 is rotated, the coupler 108 linearly moves up or down along the bolt 105, and the ends of the coupler 108 also translate along the slot 109 causing the arm 100 to rotate about the hinge or pivot 104, and moving the free end 101 of the arm 100 away and towards the bottom of the plates 20, depending on the direction of rotation of the arm bolt or screw 105. A distance 102 is defined between the free end 101 and the bottom 16 surface of the plates 20 (see, e.g. FIGS. 8 and 12). As the distance 102 is decreased, the compression between the plates 20 is increased, thus applying greater pressure on and increasingly activating the activatable seal 61. Conversely, as the distance 102 is increased, the compression between the plates 20 is decreased, thus releasing pressure on and inactivating the activable seal 61. The additional compression onto the plates 20 as achieved by the arm or toggle assemblies 110 may be applied in a step prior to the torquing of the bolts 80 to set the manhole cover 10 into the active state 92. When changing the state of the manhole cover 10 from the active state 92 to the free state 90, the bolts 80 may first be rotated to relieve pressure off the plates 30a and 50a, and then bolt screws 105 of the arms assemblies 110 may be rotated to increase the distance 102 and relieve compression off the manhole cover 10 attributed to the arms 100.

These alternative exemplary embodiments of the manhole cover 10 may also optionally further include a pipe 106 inserted through the plates 20, wherein the pipe 106 may have a flange 107 at the top end 15 of the manhole 10 (see, e.g. FIGS. 8-10 and 14). The flanged pipe 106 may allow user or operator access into the manhole 11 through the plates 20, even if the seals 60, 61 or 62 of the manhole assembly 10 are activated.

Moreover, the alternative exemplary embodiments of the manhole cover 10 in FIGS. 8-14 may optionally have two plates 20, that is a top plate 30a and a bottom plate 50a. The plates 30a and 50a may perform substantially similarly to the exemplary embodiments depicted in FIGS. 1-7 having three plates 30, 40, and 50; that is, when the plates 30a and 50a are compressed together, the activatable seals 61 in the annular cavities 22 expand or activate as the annular cavities 22 are decreased in size, and engage or seal against the manhole 11. Each of the plates 20 defines a profile at the edge, circumference, rim or perimeter 26 of the plate 20. The top plate 30a defines a profile 35 at the circumference, edge or rim 26 of top plate 30; and the bottom plate 50a defines a profile 55 at the circumference, edge or rim 26 of the bottom plate 50 (see e.g. the detailed or enlarged views as shown in FIGS. 9 and 13). Together, the profiles 35 and 55 of the assembled plates 30a and 50a define an outer surface profile or exterior surface 23 which encompasses the circumferences of the manhole cover 10. The outer surface profile or exterior surface 23 of the assembled plates 20 (including top plate 30a and bottom plate 50a in) as combined or installed against the interior surface 13 of top 12 of the manhole 11 define at least two annular cavities 22 which encircle the assembled plates 30a and 50a.

The annular cavity 22 between the top plate 30a and the bottom plate 50a may define a triangular profile 25. The triangular profile 25 is defined on the exterior surface 23 between the top plate 30a and the bottom plate 50a. Like the exemplary embodiments described for FIGS. 1-7, and as shown in the enlarged view of FIG. 13, the extension 31 of the top plate 30a defines an angled, chamfered or beveled surface or chamfer 32 which faces the bottom 16 of the manhole cover 10; and the extension 51 of the bottom plate 50a defines an angled, chamfered or beveled surface or chamfer 52 which faces the top 15 of the manhole cover 10. These angled, chamfered or beveled surfaces or chamfers 32 and 52 together with the interior surface 13 of the manhole 11, form or define the triangle profile 25 of the annular cavity 22 between the plates 30a and 50a, into which an activatable seal 61 is inserted for the alternative exemplary embodiments of FIGS. 8-14.

The annular cavity 22 of the bottom plate 50a may optionally have a rectangular or square profile 27 defined in the circumference 26 of the bottom plate 50a. This may also be a pocket or slot 28 defined within the bottom plate 50a. The rectangular or square profile 27 may be open to both the interior surface 13 and the shoulder 14 of the manhole 11 (see e.g., FIGS. 8-9, 12 and 14), or alternatively, the cavity 22 of the rectangular or square profile 27 may only be open to the interior surface 13 of the manhole 11 (see e.g. FIG. 13). As shown in the alternative exemplary embodiment of FIG. 13, the rectangular or square profile 27 or slot 28 as inscribed in the bottom plate 50a may define an optional second extension 51a of the bottom plate 50a. In the alternate exemplary embodiments depicted in FIGS. 8-9,12, and 14, the seal 62 within the rectangular or square profile 27 seals against the interior surface 13 and the shoulder 14 of the manhole 11; and as depicted in FIG. 13, the seal 62 within the rectangular or square profile 27 seals against the interior surface 13 of the manhole 11. In FIGS. 12 and 14, the lower pocket 28 may change or decrease cross sectional area as being compressed against the shoulder 14 and the tapered wall or bore 18a or wall 13 of decreasing diameter helps the seal 62 to expand outward to seal against the interior surface 13 of the manhole 11, being bounded only on two sides by the plate 50a. The decreasing diameter of the tapered bore or wall 18a may further increase sealing for all seals 60 as the manhole cover 10 is compressed into the manhole 11. The manhole cover 10 in FIG. 13 has a complete pocket or slot 28 (having three sides bounded by the plate 50a, and being open to the manhole 11 on one side); this seal 60 in FIG. 13 is compressed only by the tapered side wall 18a or wall 13 as the manhole cover 10 is installed. The seal 62 may always be actively sealing against the manhole 11 once manhole cover 10 is placed in same. The manhole cover 10 of the FIGS. 8-14 is installed by dropping or inserting into a tapered bore 18a such that the lower seal 60 or 62 will seat or activate; as the plates 30a, 50a are drawn down by the grippers 124 and wedge bar 123 (see e.g. FIG. 16) or arms 100 and bolts 105 or even gravity, the top seal 60, 61 is actuated out and the lower seal 60, 62 is further compressed.

Additionally the top plate 30a defines a projected surface 36 at the bottom of the top plate 30a. The bottom plate 50a defines a recessed surface 56 at the top of the bottom plate 50a, and a projected surface 57 at the bottom of the bottom plate 50a. When assembled, the projected surface 36 of the top plate 30a connects, fits, engages, or inserts complementarily into the recess or recessed surface 56 of the bottom plate 50a. There is a distance 24 between the plates 30a and 50a which is decreased as the manhole cover 10 goes from an inactive or free state 90 to an active or engaged state 92.

Bolts 80 may be substantially similar as described earlier for FIGS. 1-7, including slots, bolt O-rings, ports 83, and sensors 84. In the alternative exemplary embodiment as shown in the latter FIGS. 8-12, the port 83 may be drilled into the exterior surface 23 of the bottom plate 50a. As an alternative exemplary embodiment, the bolts 80 as can be seen in the enlarged view FIG. 13 may include a disc spring 71 between the plates 30a and 50a, wherein the disc spring 71 is flattened in the active state 92 (or relatively more flattened when compared to the free state 90) of the manhole cover assembly 10, and the disc springs 71 provide lift, separation, or spring between each of the plates 30a and 50a in the inactive or free state 90 of the manhole cover assembly 10.

FIG. 15 depicts a front cross section view of an alternative exemplary embodiment of an active sealing manhole cover assembly 10 with three plates 30a, 40a, 50a for a manhole 11 having a straight bore 18b. The alternative exemplary embodiment of the manhole cover 10 shown in FIG. 15 may include a brim or flange 37 about the top surface of the top plate 30a, which extends over the top of the straight bore 18b manhole 11 and retains the manhole cover 10 within the manhole 11. The exterior surface 23 of the assembled plates 30a, 40a, and 50a may, similar as described above for exemplary embodiments in FIGS. 1-7, define two annular cavities 22 which may be compressed or decreased in size or area as the manhole cover 10 is activated. The top plate 30a may have a projected surface 36 at the bottom of the top plate 30a. The middle or central plate 40a may define a recessed surface 43b at the top of the middle or central plate 40a, and a projected surface 43c at the bottom of the middle or central plate 40. The bottom plate 50a may define a recessed surface 56 at the top of the bottom plate 50a, and optionally a projected surface 57 on the bottom of the bottom plate 50a. When assembled, the recessed surface 43b of the middle or central plate 40a connects, fits, engages, or inserts complementarily into the projected surface 36 of the top plate 30a, and recessed surface 56 of the bottom plate 50a connects, fits, engages, or inserts complementarily into the projected surface 43c of the middle or central plate 40a. The alternative exemplary embodiment of the manhole cover in FIG. 15 may have an arm toggle assembly 110 and bolts 80 as described in the earlier embodiments shown in FIGS. 8-14 which can activate the seals 61 against the straight bore or wall 18b of the interior surface 13 of the manhole 11.

FIG. 16 depicts a front cross section view of an alternative exemplary embodiment of an active sealing manhole cover assembly 10 with one plate 20 for a manhole 11 and having a wedge actuation assembly, wedge bar assembly, or wedge gripping bar assembly 120. The plate 20 may define one or more annular cavities 22 into which seal(s) 60 may be inserted. These cavities 22 may have any profiles as described in earlier embodiments in this disclosure, including grooves or slots 28. The wedge gripping bar assembly 120 may include, optionally, a spring plate 121, one or more actuation bolts or screws 122, a wedge bar 123, one or more wedges or wedge grippers 124, wedge studs 125, a stopping pin or other stopping device or means 126, and a wedge plate 127. The wedge gripping bar assembly 120 may be adjacent or abutting the bottom of the plate 20 in FIG. 16 via the spring plate 121. A number of wedge studs 125 is inserted into the spring plate 121 at one end of the wedge studs 125; the opposite end of each wedge stud 125 is inserted into a wedge gripper 124, wherein the wedge gripper 124 may have a roughened or textured exterior surface for enhanced gripping of the interior surface 13 of the manhole 11. The wedge gripper 124 is slidably inserted onto a wedge bar 123 having a wider base at the bottom than the top of the wedge bar 123. A wedge plate 127 may optionally be in between the wedge gripper 124 and the wedge bar 123, wherein the wedge plate 127 decreases the friction experienced by the wedge gripper 124 as the wedge gripper 124 moves, slips, maneuvers, or slides against the wedge bar 123. The wedge bar 123 may, in certain exemplary embodiments, optionally be frustoconical in shape. The wedge bar actuation screw 122 is inserted through the plate 20, the spring plate 121 and the wedge bar 123 and may pull the plate 20 down and push the wedge bar 123 up as the screws 122 are tightened, or otherwise compress the plate 20 and wedge bar 123 together; as the screws 122 are loosened, the plate 20 and wedge bar 123 may move apart from each other. The bottom end of the actuation screw 122 may have a stop pin 126 or other stopping means 126 (such as a flange, or a washer) as known to one of ordinary skill in the art. The wedge gripping bar assembly 120 may also be used in connection with embodiments having multiple plates 20; further, the toggle arm assembly 110 may be used in place of the wedge gripping bar assembly 120 with the single plate 20.

In the single plate 20 exemplary embodiment with two seals 60, the sealant port 83 may be a cross drilled port 83 drilled and tapped in the plate 20 in one preferably more locations that have threaded plugs or bolts 80 in the top 15 outer face of the manhole cover 10.

In alternative exemplary embodiments with a single plate 20 having two complete seal grooves or slots 28, the manhole cover 10 may seal by pure compression of a seal 60 with a larger free outer diameter into a straight bore 18b or tapered bore 18a manhole 18 that has a slightly smaller interior diameter surface 13. In these alternative exemplary embodiments, the manhole cover 10 should be either bolted in via the toggle arm assembly 110, bolts 80, or gripping mechanism 120 that can keep, retain, or hold the manhole cover 10, plate 20 and seals 60 in the correct active position 92 in the manhole 11. Even minor pressure on the large cover area of the manhole cover 10 could lift the plate 20 causing the plate 20 to burp out gas or cause the seals 60 to be pushed up to an area where the seals 60 no longer have an effective seal. The disclosed wedge bar gripping mechanism 120, bolting 80, or toggle arm assembly 110, will prevent such displacement of the seals 60 and the cover 10.

To actuate the alternative exemplary embodiment of the manhole cover 10 shown in FIG. 16, once the cover 10 is first inserted into a manhole 11, the actuation screws 122 are tightened, rotated, or torqued to raise the wedge bar 123 up towards the top 15 of the manhole 11 or towards the plate 20. As the wedge bar 123 is raised towards the plate 20, the gripping wedges or wedge grippers 124 are pushed outwards and slide down the wider base of the wedge bar 123 towards the straight walls or straight bore portion of interior surface 13 of the manhole 11 (see, e.g. the active state 124a of the wedge gripper 124 in the left side of the FIG. 16). If present, the optional coating, roughening, or texturing on the exterior surface of the wedge gripper 124 will engage the interior surface 13 and increase or secure the hold of the manhole cover 10 in the manhole 11. The actuation screws 122 are further tightened, rotated, or torqued which pulls the plates 20 down into the manhole 11 to fully seat or engage the seals 60 against the interior 13 of the manhole 11. In exemplary embodiments within a tapered bore 18a, as the plates 20 are pulled or compressed downwards, the seals 60 will increasingly seat or engage with the manhole 11 as the interior diameter or surface 13 decreases in the tapered bore 18a. A quantity of sealant 85 may optionally be injected into the ports 83 (such as via the plugs or bolts 80) to fill or partially fill into the annular space 86 bounded by the seals 60 at the top and bottom, the exterior surface of the manhole cover 10, and the interior surface 13 of the manhole 11. Rotating the actuation screws 122 in the opposite direction will move the plate 20 and the wedge bar 123 farther away from each other, and allows the wedge grippers 124 to retract away from the interior 13 of the manhole 11 as the wedge grippers 124 slide towards a top or smaller diameter end of the wedge bar 123. See, e.g. the inactive state 124b of the wedge grippers 124 as disengaged from the interior 13 of the manhole 11, towards the right side of the FIG. 16. The stop pin or other stopping means 126 prevents accidental or inadvertent dropping of the wedge bar 123.

While the exemplary embodiments are described with reference to various implementations and exploitations, it will be understood that these exemplary embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions, and improvements are possible.

Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.

Claims

1. A method for sealing a manhole against emissions, wherein the manhole defines an interior surface, comprising the steps of:

inserting a manhole cover into the manhole, wherein the manhole cover comprises a top plate and a bottom plate and wherein the manhole cover further comprises a first seal ring in a first annular cavity defined in an exterior surface of the manhole cover and a second seal ring in a second annular cavity defined in the exterior surface of the manhole cover;

compressing the top plate, and the bottom plate together;

decreasing the first annular cavity; and

engaging the first seal ring and the second seal ring against the interior surface of the manhole.

2. The method according to claim 1, wherein the first annular cavity has a profile defined by a chamfer of the top plate and a chamfer of the bottom plate.

3. The method according to claim 2, wherein the step of decreasing the first annular cavity comprises the step of moving the chamfer of the top plate towards the chamfer of the bottom plate.

4. The method according to claim 3, wherein the manhole cover further comprises a plurality of bolts inserted through the top plate, and the bottom plate.

5. The method according to claim 1, wherein the step of compressing the top plate, and the bottom plate together comprises the step rotating the plurality of bolts in a first direction and moving an end of the plurality of bolts towards a bottom of the manhole.

6. The method according to claim 5, wherein the manhole cover further comprises at least one arm hinged to the bottom plate at a first end of the at least one arm, and wherein a second end of the at least one arm is pivotable away from and towards the bottom plate.

7. The method according to claim 6, wherein the step of compressing the top plate and the bottom plate together further comprises pivoting the second end of the at least one arm towards the bottom plate.

8. The method according to claim 7, wherein the top plate defines a first projected surface and the bottom plate defines a first recessed surface, and further comprising the steps of complementarily engaging the first projected surface with the first recessed surface, during the step of compressing the top plate and the bottom plate together.

9. The method according to claim 8, further comprising the step of lifting the top plate from the bottom plate via a set of disc springs around the plurality of bolts.

10. The method according to claim 9, further comprising the steps of releasing the first seal ring from the interior surface of the manhole by rotating the plurality of bolts in a second direction and moving the plurality of bolts away from the bottom of the manhole; and pivoting the second end of the at least one arm away from the bottom plate.

11. The method according to claim 10, further comprising the step of sensing a pressure of the manhole cover assembly via a port drilled within the bottom plate.

12. The method according to claim 11, wherein the first annular cavity defines a triangular shaped profile with the interior surface of the manhole.

13. The method according to claim 12, wherein the manhole cover further comprises a middle plate between the top plate and the bottom plate; and wherein the second annular cavity comprises a second profile having a second triangular shape defined between the middle plate and the bottom plate and the interior surface of the manhole.

14. A manhole cover assembly for sealing a manhole against emissions, wherein the manhole defines an interior surface, comprising:

a top plate;

a bottom plate beneath the top plate;

a first plurality of fasteners inserted into the top plate and the bottom plate;

a first annular cavity defined about an exterior surface of the manhole cover;

a second annular cavity defined about the exterior surface of the manhole cover;

a first flexible seal inserted in the first annular cavity configured to seal against the interior surface in an active state of the manhole cover assembly and configured to disengage from the interior surface in a free state of the manhole cover assembly; and

a second flexible seal inserted into the second annular cavity configured to seal against the interior surface.

15. The manhole cover assembly of claim 14, wherein the first annular cavity is decreased in size when the manhole cover assembly is in the active state as compared to when the manhole cover assembly is in the free state.

16. The manhole cover assembly of 15, further comprising a second plurality of fasteners inserted through the top plate and the bottom plate, and further comprising an arm connected to each of the second plurality of fasteners, wherein a first end of the arm is hinged to a bottom of the bottom plate.

17. The manhole cover assembly of claim 16, further comprising a first distance between the top plate and the bottom plate, and wherein the first distance is shorter in the active state of the manhole cover assembly and greater in the free state of the manhole cover assembly.

18. The manhole cover assembly of claim 17, further comprising a first set of disc springs around each of the plurality of fasteners and between the top plate and the bottom plate.

19. The manhole cover assembly according to claim 18, wherein the first set of disc springs is more flattened in the active state of the manhole cover assembly than in the free state of the manhole cover assembly.

20. The manhole cover assembly according to claim 19, wherein the first flexible seal and the second flexible seal are each constructed of VITON™ material.

21. A method for sealing a manhole against leaking vapor and emissions, comprising the steps of

torquing a number of bolts in a manhole cover in a first direction to install the manhole cover into the manhole, wherein the manhole cover comprises a plurality of plates stacked together and an annular cavity between each of the plurality of plates, wherein the annular cavity is defined at the exterior surface of the manhole cover, and further comprising an O-ring in the annular cavity;

compressing the plurality of plates together and decreasing a size of the annular cavity;

pushing the O-ring towards an interior surface of the manhole; and

sealing the manhole via the O-ring.

22. The method according to claim 21, further comprising the step of pivoting a first end of an arm towards a bottom of the plurality of plates, wherein the arm is hinged to the bottom of the plurality of plates at a second end of the arm, and increasing the compression between the plurality of plates.

23. The method according to claim 22, wherein the plurality of plates comprises at least two plates.

24. A manhole cover for sealing a manhole, comprising

a top plate defining a top plate angled surface around a perimeter of the top plate, wherein the top plate angled surface faces a bottom of the manhole cover;

a bottom plate beneath the top plate, and wherein the bottom plate defines a bottom plate angled surface around a perimeter of the bottom plate, and wherein the bottom plate angled surface faces a top of the manhole cover; and

a first O-ring situated between the top plate angled surface and the first middle plate angled surface.

25. The manhole cover according to claim 24, further comprising a plurality of bolts inserted through the top plate and the bottom plate, wherein the plurality of bolts are configured to compress the top plate and the bottom plate together when rotated in a first direction, and wherein the plurality of bolts are configured to release the compression between the top plate and the bottom plate when rotated in a second direction opposite the first direction.

26. The manhole cover according to claim 25, further comprising a plurality of arms hinged to a bottom of the bottom plate at a first end of each of the plurality of arms; and a second end of each of the plurality of arms configured to be pivotable away from and towards the bottom of the bottom plate.

27. The manhole cover according to claim 26, wherein the second end of each of the plurality of arms can be set at a first distance and at a second distance from the bottom of the bottom plate.

28. The manhole cover according to claim 27, wherein the first distance is shorter than the second distance, and further wherein when the second end of the plurality of arms is at the first distance from the bottom of the bottom plate, the top plate and the bottom plate are more compressed together than when the second end of the plurality of arms is at the second distance from the bottom of the bottom plate.

29. The manhole according to claim 25, further comprising a middle plate beneath the top plate and above the bottom plate, and wherein the middle plate defines a first middle plate angled surface around a perimeter of the middle plate and a second middle plate angled surface around the perimeter of the middle plate, and wherein the first middle plate angled surface faces the top plate angled surface.

30. The manhole according to claim 29 further comprising a second O-ring situated between the second middle plate angled surface and the bottom plate angled surface.

31. A manhole cover for sealing a manhole having an interior surface, comprising:

a plate defining an annular cavity about an exterior surface of the plate;

a seal inserted into the annular cavity;

a wedge bar below the plate, wherein the wedge bar has a base wider than a top;

a wedge gripper configured to be slidable on a surface of the wedge bar; and

a screw inserted through the plate and the wedge bar, wherein the screw is configured to compress the plate and the wedge bar together.

32. The manhole cover of claim 31, wherein an exterior surface of the wedge gripper engages the interior surface of the manhole in an active position of the wedge gripper, and wherein the exterior surface of the wedge gripper does not engage the interior surface of the manhole in an inactive position of the wedge gripper.

33. The manhole cover of claim 32, wherein the screw is configured to pull the plate down and the wedge bar up when the screw is rotated in a first direction; and wherein the screw is configured to separate the plate and the wedge bar when the screw is rotated in a second direction opposite to the first direction.