Patent Publication Number: US-2023146258-A1

Title: Sealing and Locking Valve Box Lid

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a lid apparatus for covering and sealing a valve box, and, more particularly, to a flush-mounting lid utilizing a seal element that fits around the outer circumference of a depending side wall of the lid apparatus. 
     Water lines, sewer lines, and other utilities such as electrical wiring and the like are typically buried under public rights of way, such as streets, alleys, and easements. Access openings are spaced at intervals throughout the system of utility lines. In the case of water utilities, the access openings provide access to shut off valves that allow selectively isolating sections of the pipe in the event of a break or leak in the system. The shut off valves are frequently buried below the street. Access pipes or openings extend upwardly from the buried valves to the surface to provide a passage for a tool or hand to selectively actuate the valve between its on and off positions. A cover assembly having a removable lid has traditionally been used to prevent debris from entering the access pipe. 
     Referring to  FIG.  1   , municipalities often bury water a supply main  1  under a public right of way, in this case, a roadway  3 . Valve boxes  5  are spaced at intervals throughout the pipe system  100  and can be used to isolate sections of the pipe, for example, a branch line  7  to a fire hydrant  9 , in the event of a break or leak in the pipe system  100 . Frequently, the supply main  1  will be located under the center of the roadway  3  and the valve box  5  will be located between the supply main  1  and a curb  11 . A shutoff valve  13  is positioned within (typically beneath) the valve box  5 . An opening at the top of the valve box  5  enables a worker to access the shutoff valve  13  by hand or with a tool from the surface. 
     When access openings such as the valve box  5  are left uncovered, they tend to accumulate debris and water, and pose a threat to people and vehicles in proximity to the access openings. Traditionally, a simple lid  15  comprising a metal plate sits inside the opening of the valve box  5 . This type of lid  15  does not prevent water and fine particles from seeping into the valve box  5  and interfering with the operation and maintenance of the shutoff valve  13 . This type of lid  15  is also susceptible to being displaced by vehicular traffic or being stolen by vandals. 
     Large flat steel plates (not shown) are sometimes used to cover access openings, for example, during construction. These plates are difficult to handle and position, and do not stop dirt, dust and other objects from entering the access opening beneath the steel plates, when the steel plates are not precisely aligned with the top of the access opening. Misaligned steel plates may form a safety hazard for vehicles passing over them, and do not stop vandals from removing the steel plates. The plates also do not provide a flush surface, impeding vehicular traffic and creating a tripping hazard for pedestrians. 
     Efforts have been made to provide sealed valve box lids. U.S. Pat. No. 4,461,597, teaches a sealable lid using movable “fingers” that extend outward from the underside of the lid to grip the walls of the valve box. This design is not desirable because the structure necessary to support the fingers is relatively complex and extends a significant distance below the lid, which is not suitable for shallow installations, where limited clearance between the top of the valve actuator and the top of the valve box. U.S. Pat. No. 6,887,012 teaches a sealable lid having a lip that rests atop the valve box—providing the convex/domed surface that protrudes above the upper edge of the valve box. This is similarly undesirable because the lid protrudes upwardly from the valve box, creating a bump for anything driving over the valve box. 
     Accordingly, there is an unmet need for a sealable valve box lid assembly that can provide a water-tight seal between the valve box and ground surface, that is capable of supporting heavy downward loads created by vehicle traffic, and that has a low profile that is suitable for shallow valve box installations. 
     SUMMARY OF THE INVENTION 
     The sealable and lockable valve box lid assembly disclosed herein 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 profile that is suitable for shallow valve box installations. 
     When in a locked position, the valve box lid assembly is adapted to transmit downward loads (such as the load applied when a truck drives over the lid) through the lid assembly and to the valve box ledge. The valve lid is adapted to provide a low-profile design, meaning that the distance between the upper surface of the assembly and the bottom surface of the assembly is minimized. This provides the clearance to enable valve actuators to be located closer to the upper edge of the valve box. The valve box lid assembly is designed to enable the top surface of the assembly to be flush with the upper edge of the valve box when the assembly is installed in the valve box and in a locked position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will hereinafter be described in conjunction with the appended drawing figures wherein like numerals denote like elements. 
         FIG.  1    is a view of a prior art valve box and lid in its use environment. 
         FIG.  2    is an exploded view of an embodiment of the sealing and locking valve box lid of the claimed invention. 
         FIG.  3    is a top view thereof. 
         FIG.  4 A  is a sectional view thereof, taken along line  4 A- 4 A of  FIG.  3   , showing the valve box lid of in an unlocked position. 
         FIG.  4 B  is a sectional view thereof, taken along line  4 A- 4 A of  FIG.  3   , showing the valve box lid of in a locked position. 
         FIG.  5 A  is a sectional view thereof, taken along line  4 A- 4 A of  FIG.  3   , showing the valve box lid of in an unlocked position and positioned in a valve box. 
         FIG.  5 B  is a sectional view thereof, taken along line  4 A- 4 A of  FIG.  3   , showing the valve box lid of in a locked position and positioned in a valve box. 
         FIG.  6    is a sectional view (taken at the same location of  FIG.  5 B ) showing another exemplary embodiment of the sealing and locking valve box lid in an unlocked configuration and installed on a valve box. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The ensuing detailed description provides preferred exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the invention. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention, as set forth in the appended claims. 
     To aid in describing the invention, directional terms are used in the specification and claims to describe portions of the present invention (e.g., upper, lower, left, right, etc.). These directional definitions are merely intended to assist in describing and claiming the invention and are not intended to limit the invention in any way. In addition, reference numerals that are introduced in the specification in association with a drawing figure may be repeated in one or more subsequent figures without additional description in the specification in order to provide context for other features. 
       FIG.  2    displays an exploded view of an embodiment of the sealing valve box lid assembly. Referring to  FIG.  2   , the lid assembly  200  comprises an upper plate  202  having a centrally located first aperture  204  extending therethrough. The upper plate  202  further comprises a top surface  208  and upper mating surface  212  that opposes the top surface  208 . A centrally located second aperture  206  is between the first aperture  204  and the top surface  208 . Recesses  205   a ,  205   b  provide a means for the assembly to be removed from its installed location. The second aperture  206  is larger in diameter than the first aperture  204  and the apertures  204 ,  206  are preferably concentric. The upper plate  202  has an outer edge  214  located along a perimeter of the upper plate  202  and between the top surface  208  and the upper mating surface  212 . The upper plate  202  may be formed of any strong, rigid material. A preferred material is ductile iron. 
     A sealing element  220  is disposed below the upper plate  202  and above a lower plate  222 . The sealing element  220  is comprised of an elastomeric material having an annular shape having an inner surface  221  and an outer surface  223 . The lower plate  222  is disposed below the first plate  202  and the sealing element  220 . The lower plate  222  comprises a lower mating surface  228  and an outer edge  226  disposed along a perimeter of the lower plate  222 . The lower plate  222  comprises an aperture  224  that is configured to engage with a threaded fastener  240 . The lower plate aperture  224  may itself be threaded (not shown) to engage the threaded fastener. In the embodiment illustrated in  FIG.  2   , the threaded fastener  240  engages a separate nut  247  having a threaded aperture  246  that sits inside the aperture  224  of the lower plate. 
     The threaded fastener  240  is adapted to pass through the first aperture  204  and second aperture  206  of the upper plate  202  and engage with a threaded aperture  246  of the lower plate  222 . The threaded aperture  246  in the lower plate  222  is preferably formed in a nut  247  that is separable from the lower plate  222 . This prevents the fastener  240  from protruding upwardly from the upper plate  202  when the fastener  240  is installed but not fully tightened, which avoids creating a trip hazard or damage caused by a vehicle striking the fastener  240 . This design also prevents vertical loads from being transferred through the threads of the fastener  240 , particularly when the fastener  240  is in an unlocked/untightened position. The head  242  of threaded fastener  240  has a diameter that is greater than the diameter of the first aperture  204  and less than the diameter of the second aperture  206  so that the head sits inside the recess created by the second aperture. The head  242  may have a tamper-resistant shape (i.e., a shape that is not engageable using standard wrenches or sockets). An upper washer  244  having a rubber layer on one side provides a seal around the fastener  240 . A snap ring  248  is preferably included on the lower end of the fastener  240  to prevent the nut from becoming disconnected from the fastener  240 . 
     Referring again to  FIG.  2   , the lid  200  is assembled by passing the threaded fastener  240  through the apertures  204 ,  206  of the upper plate  202  to engage the threaded aperture  246  of the lower plate  222 . The sealing element  220  is secured between the upper and lower plates  202 ,  222 . The diameter of the annular sealing element  220  is selected so that the inner surface  221  of the sealing element contacts the outer edge  214  of the upper plate and the outer edge  226  of the lower plate. The threaded fastener  240  is thereby operationally configured to draw the upper and lower plates  202 ,  222  together or apart by rotating the threaded fastener  240  clockwise or counterclockwise, respectively. 
       FIG.  3    is a top view of the sealing valve box lid assembly  200 . From this perspective, it is seen that the outer surface  223  of the sealing element extends beyond the outer edge  214  of the upper plate&#39;s top surface  208 . The head of fastener  240  resides in the recess created by the second aperture  206 . The functioning of the sealing valve box lid is described below in reference to a cross-sectional view of the assembly along line  4 A- 4 A. 
       FIGS.  4 A and  4 B  are sectional views, taken along lines  4 A- 4 A of  FIG.  3   , of the lid assembly  200 .  FIG.  4 A  shows the lid assembly  200  in an unsealed position and  FIG.  4 B  shows the lid assembly in a sealed position. The lid assembly  200  is transitioned between the sealed position and unsealed positions by rotating the threaded fastener  240  clockwise or counterclockwise. 
     Referring to  FIG.  4 A , in the unsealed position, the upper mating surface  212  of the upper plate  202  is spaced apart from the lower mating surface  228  of the lower plate  222 . The outer edge of the upper plate  202  comprises an upper retaining recess  216  which grips the upper portion of the sealing element  220 . The outer edge of the lower plate  226  comprises a lower retaining recess  230  which grips the lower portion of the sealing element  220 . The outer surface  223  of the sealing element  220  protrudes a first distance beyond the outer edge of the top plate  214  and the outer edge of the lower plate  226 . 
     The lower plate  222  further comprises a lower surface  234  that opposes the lower mating surface  228 , and a lower edge  236  that opposes the lower retaining recess  230 . The lower edge  236  extends below the lower mating surface  228 , thereby defining a lower recess  238  between the lower edge  236  and the lower mating surface  228 . 
     As noted above, one feature of the lid assembly  200  is to provide clearance for shallow installations. To this end, the lower plate  222  has a lower plate thickness (a) extending from the lower mating surface  228  to the lower surface  234  and the lower recess  238  has a lower recess height (b) extending vertically from the lower surface  234  to the lower edge  236 , the lower recess height (b) being at least three times the lower plate thickness (a). In another respect, preferably no element in the lower recess  238  extends below the lower edge  236 . More preferably the lower-most extending element within the lower recess  238  (in this case, the lower end of the fastener  240 ) is spaced upwardly from the lower edge  236  a distance (d) that is at least 10% (most preferably at least 20%) of the overall height (c) of the lid assembly  200  when in a sealed/closed position. 
     In the unsealed position, the head  242  of the threaded fastener  240  is located at least partially within the second aperture  206 . 
     Referring to  FIG.  4 B , in the sealed position, the upper mating surface  212  of the upper plate  202  is in contact with the lower mating surface  228  of the lower plate  222 . Drawing the upper plate  202  and lower plate  222  together also moves the upper retaining recess  216  and lower retaining recess  230  closer together, thereby compressing the elastomeric sealing element  220 . As a result of the compression, the outer surface of the sealing element  220  is pushed outward, to protrude a second distance beyond the outer edge of the upper plate  202  and the outer edge of the lower plate  226 , where the second distance is greater than the first distance in the unsealed position. When the lid assembly is installed in a valve box, the outward protrusion of the sealing element  220  in the lock position presses the outer surface  223  of the sealing element against the wall of the valve box to create a water-tight seal. 
     The top edge of the upper retaining recess  216  is located above the upper mating surface  212  and the bottom edge of the lower retaining recess  230  is located below the lower mating surface  232 . This enables the gasket to expand outwardly when “pinched” by the gasket-retaining recesses but remain in a seated position when the plate mating surfaces are in contact with one another. In the sealed position, the head  242  of the threaded fastener  240  is preferably flush with the top surface  208  of the top plate  202   
       FIGS.  5 A and  5 B  show the sealing valve box lid assembly installed in a valve box. In the interest of clarity, some features that are shared with a previous figure are numbered in  FIGS.  5 A and  5 B , but are not repeated in the specification.  FIG.  5 A  shows the lid in an unsealed position and  FIG.  5 B  shows the lid assembly  200  in a sealed position. The valve box  252  comprises a cylindrical housing having a side wall  254  and a top edge  256  located at the upper edge of the sidewall and defining a circular top aperture. The side wall  254  comprises a ledge  258  located below and distal to the top edge  256  and extending inwardly from the sidewall  254 . The valve box  252  surrounds and protects a valve position indicator  262  and a valve actuator  260 . 
     Referring to  FIG.  5 A , when the lid assembly is installed in the valve box  252 , the lower edge  236  of the lower plate  222  rests on the ledge  258  located in the sidewall  254  of the valve box  252 . The top surface  208  of upper plate  202  protrudes upwardly from the top edge  256  of the valve box  252  when the lower edge  236  is engaged with the ledge  258  and the lid assembly is in the unsealed position. The outer surface  223  of the sealing element  220  is located opposite the sidewall  254  of the valve box  252 . 
     Referring to  FIG.  5 B , when the lid assembly  200  is in the locked position, the upper plate  202  and lower plate  222  are drawn together such that the upper mating surface  212  contacts the lower mating surface  228 . The upper retaining recess  216  and lower retaining recess  230  compress the elastomeric sealing element  220 , causing the outer surface  223  of the sealing element  220  to engage with the side wall  254  of the valve box  252  along the entire outer surface of the sealing element, thereby creating a water-tight seal between the sealing element and the side wall. 
     When the lid assembly is installed in the valve box and in the sealed position, the top surface  208  and the head of the fastener  240  are both either (a) flush with the top edge  256  of the valve box  252  or (b) located below the top edge  256  of the valve box  252 . This creates a flush surface along the entire upper surface of the valve box and lid assembly, such that when the valve box is installed flush with the surrounding pavement or road surface provides a smooth surface for pedestrians and vehicular traffic. 
     When the lid assembly is installed in the valve box and in the sealed position, downward loads on the top surface  208  of the upper plate  202  are transmitted first to the lower plate  222  via the contacting upper mating surface  212  and lower mating surface  228 , and then to the valve box  252  via the lower edge  236  of the lower plate contacting the ledge  258  in the valve box side wall  254 . This arrangement allows the lid assembly to support relatively heavy downward loads, such as those created by vehicles and construction equipment driving over the lid assembly. 
     Unlike existing expandable pipe plugs that are not designed to support downward loads, the upper and lower plates of the disclosed lid assembly have mating surfaces that are configured to contact each other when the valve lid is in a locked position. This enables the sealed assembly to function as a unit to transfer the downward load to valve box ledge. 
     The shape of the lower plate  222  is designed so that the lid assembly can provided a sealed cover that supports downward loads even in valve boxes where there is low clearance between the valve actuator  260  and the top edge  256  of the valve box. Referring again to  FIGS.  4 A and  4 B , the distance (b) between the lower edge  236  of the lower plate is at least three times the thickness (a) of the lower plate. This creates a lower recess  438  that provides clearance between the lower plate and valve actuator, even in relatively shallow valve box installations. 
       FIG.  6    illustrates an alternate embodiment of the sealing and locking valve box lid. In  FIG.  6   , elements shared with  FIGS.  2  through  5 B  are represented by reference numerals increased by factors of  100 . For example, the sealing element  220  in  FIG.  2    corresponds to the sealing element  320  in  FIG.  6   . In the interest of clarity, some features that are described in connection with a previous figure are numbered in  FIG.  6    but are not repeated in the specification. 
     In  FIG.  6   , the upper mating surface  312  and the lower mating surface  328  are not planar surfaces, as in the embodiment of  FIGS.  4 A and  4 B , but have complimentary geometries that nevertheless perform the mating function. In addition, the lower edge  336  of lower plate  322  illustrates alternate design for engaging the ledge  358  of the valve box. One of skill in the art will recognize that minor design modifications such as these are possible to accommodate varied valve box geometries while still retaining the functions of the claimed valve box lid assembly. 
     While the principles of the invention have been described above in connection with preferred embodiments, it is to be clearly understood that this description is made only by way of example and not as a limitation of the scope of the invention.