Sealing and locking valve box lid
A sealable and lockable valve box lid assembly provides a water-tight seal between the valve box and ground surface, is capable of supporting heavy downward loads created by vehicle traffic, and has a low vertical profile that is suitable for shallow valve box installations. The lid assembly may be flush with the ground when in a closed position, allowing overhead vehicle traffic to pass over a flat surface.
1 . A lid assembly comprising:
a first plate having a first aperture extending therethrough and having a first diameter, a top surface, a first mating surface that opposes the top surface, a first outer edge located along a first perimeter of the first plate and between the top surface and the first mating surface, and a first retaining recess located between the first mating surface and the first outer edge;
a second plate disposed below the first plate, the second plate comprising a second outer edge, a threaded aperture, a second mating surface and a second retaining recess located at an upper end of the second outer edge and between the second mating surface and the second outer edge;
a sealing element formed of a ring of elastomeric material and disposed between the first retaining recess and the second retaining recess; and
a fastener disposed in the first aperture and the threaded aperture, the fastener having a threaded body and a head having a head diameter;
wherein the lid assembly has an unsealed position in which the fastener extends through the first aperture and is engaged with the threaded body and the first and second mating surfaces are spaced apart; and
wherein the lid assembly has a sealed position in which the first mating surface is in contact with the second mating surface and the sealing element is compressed by the first retaining recess and the second retaining recess, thereby causing the sealing element to protrude outwardly from the first and second outer edges a greater distance than when in the unsealed position.
2 . The lid assembly of claim 1 , wherein the second plate further comprises a lower edge that is distal to the second retaining recess and is located at a lower end of the second outer edge.
3 . The lid assembly of claim 2 , wherein the second plate further comprises a lower surface that opposes the second mating surface, the lower edge being located below the lower surface, thereby defining a lower recess between the lower edge and the lower surface.
4 . The lid assembly of claim 3 , wherein the second plate has a second plate thickness extending from the second mating surface to the lower surface and the lower recess has a lower recess height extending vertically from the lower surface to the lower edge, the lower recess height being at least three times the second plate thickness.
5 . The lid assembly of claim 1 , wherein the first plate further comprises a second aperture located between the first aperture and the top surface, the second aperture having a second diameter that is larger than the first diameter and the head diameter.
6 . The lid assembly of claim 5 , wherein the head of the fastener is located at least partially within the second aperture when the lid assembly is in the unsealed position and the sealed position.
7 . The lid assembly of claim 1 , wherein the threaded aperture comprises part of a nut that is removably inserted into the second plate.
8 . A valve box assembly comprising:
a valve box having a side wall, a top edge located at an upper end of the side wall, a ledge located below and distal to the top edge, the ledge extending inwardly from the side wall, the top edge defining a top aperture;
a lid assembly comprising:
a first plate having a first aperture extending therethrough and having a first diameter, a top surface, a first mating surface that opposes the top surface, a first outer edge located along a first perimeter of the first plate and between the top surface and the first mating surface, and a first retaining recess located between the first mating surface and the first outer edge;
a second plate disposed below the first plate, the second plate comprising a threaded aperture, a second mating surface and a second retaining recess disposed along a second perimeter of the second plate;
a sealing element formed of a ring of elastomeric material and disposed between the first retaining recess and the second retaining recess, the sealing element having an outer surface; and
a fastener disposed in the first aperture and the threaded aperture, the threaded fastener having a threaded body and a head having a head diameter;
wherein the lid assembly has an unsealed position in which the first and second mating surfaces are spaced apart;
wherein the lid assembly has a sealed position in which the first mating surface is in contact with the second mating surface and the sealing element is compressed by the first plate and the second plate, thereby causing the sealing element to protrude outwardly from the first and second edges a greater distance than when in the unsealed position; and
wherein the sealing element engages the side wall along the entire outer surface of the sealing element, thereby creating a water-tight seal between the sealing element and the side wall.
9 . The valve box assembly of claim 8 , wherein the second plate further comprises a lower edge that opposes the second retaining recess, the lower edge being adapted to engage the ledge when the lid assembly is fully inserted into the valve box.
10 . The valve box assembly of claim 9 , wherein the lid assembly in the sealed position is adapted to transmit a downward load on the top surface of the upper plate to the valve box ledge via the lower edge.
11 . The lid assembly of claim 8 , wherein when the second sealing plate has a lower edge that is engaged with the ledge and the lid assembly is in the sealed position, the top surface and the head of the fastener are both either (a) flush with the top edge of the valve box or (b) located below the top edge of the valve box.
12 . The lid assembly of claim 11 , wherein the second sealing plate includes a lower recess located below and opposing the second mating surface, the lower edge forming a perimeter around a lower end of the lower recess.
13 . The lid assembly of claim 11 , wherein when the lower edge is engaged with the ledge, the top surface protrudes upwardly from the top edge of the valve box when the lid assembly is in the unsealed position.
14 . A lid assembly comprising:
a first plate having a first aperture extending therethrough and having a first diameter, a top surface, a first mating surface that opposes the top surface, a first outer edge located along a first perimeter of the first plate and between the top surface and the first mating surface, and a first retaining recess located between the first mating surface and the first outer edge;
a second plate disposed below the first plate, the second plate comprising a second outer edge, a threaded aperture, a second mating surface and a second retaining recess located at an upper end of the second outer edge and between the second mating surface and the second outer edge;
a sealing element formed of a ring of elastomeric material and disposed between the first retaining recess and the second retaining recess; and
a fastener disposed in the first aperture and the threaded aperture, the fastener having a threaded body and a head having a head diameter;
wherein the lid assembly has an unsealed position in which the fastener extends through the first aperture and is engaged with the threaded body, the first and second mating surfaces are separated by a first distance, and the second retaining recess is located below the first mating surface;
wherein the lid assembly has a sealed position in which the first mating surface and the second mating surface are separated by a second distance and the sealing element is compressed by the first retaining recess and the second retaining recess, thereby causing the sealing element to protrude outwardly from the first and second outer edges a greater distance than when in the unsealed position, the second distance being less than the first distance;
wherein the second plate further comprises a lower edge that is distal to the second retaining recess and is located at a lower end of the second outer edge; and
wherein the second plate further comprises a lower surface that opposes the second mating surface, the lower edge being located below the lower surface, thereby defining a lower recess between the lower edge and the lower surface.
15 . The lid assembly of claim 14 , wherein the second plate has a second plate thickness extending from the second mating surface to the lower surface and the lower recess has a lower recess height extending vertically from the lower surface to the lower edge, the lower recess height being at least three times the second plate thickness.
16 . The lid assembly of claim 1 , wherein the second retaining recess is located below the first mating surface when the lid assembly is in the unsealed position.
17 . The lid assembly of claim 1 , wherein the second retaining recess is located below the second mating surface.