Abstract: A template for temporary placement on the open upper end of a below-ground structure, including a rectangular body matching key dimensions of a permanent ground-level member to be installed, the body having an open bottom to engage the open upper end of the below-ground structure, a raised top surface, a back road-edge portion on one side of the body, and upright sidewalls. A method for using the template to facilitate adjustment of positioning of below-ground structures on which permanent ground-level members will be installed, the method involving placing, removing and re-placing the template while determining and adjusting positioning of the below-ground structure.

Abstract: A template for temporary placement on the open upper end of a below-ground structure, including a body matching key dimensions of a permanent ground-level member to be installed, the body having an open bottom to engage the open upper end of the below-ground structure, a raised top surface, and an upright sidewall. A method for using the template to facilitate adjustment of positioning of below-ground structures on which permanent ground-level members will be installed, the method involving placing, removing and re-placing the template while determining and adjusting positioning of the below-ground structure.

Abstract: A method and a device for safely and efficiently adjusting the height of a manhole freely allowing the addition and removal of a height adjusting member at any position. The method and device may be used for the manhole formed by installing a tubular shaped frame in the ground, installing the removable height adjustment members on the tubular shaped frame, and installing a cover receiving frame on the height adjusting members. In this method and device, a frame is disposed in the upper space of the manhole; the cover receiving frame is raised by the height adjusting member installed on the frame; and the height adjusting members positioned under the cover receiving frame in that state are added or removed.

Abstract: A manhole access way security apparatus and method for using the security apparatus are disclosed. The security apparatus includes an insert, at least one locking pin and a locking mechanism each interconnected to allow users to easily and quickly install a security barrier under a manhole, handhole or vault, and thereby prevent authorized access through the manhole, handhole or vault. The apparatus uses an insert that may either sit on the existing manhole frame rim under the manhole cover, or if there is insufficient clearance on the manhole frame rim, brackets may be installed under the manhole frame upon which the insert rests. In either configuration, the insert is secured in place under the manhole cover by one or more locking pins that extend radially through the insert and are then locked to the insert.

Abstract: A riser assembly for supporting a manhole cover is placed within a manhole frame for raising the height of the manhole cover to pavement level. The riser assembly includes a circular frame formed of a metal bar and has a locking ring attached thereto which extends vertically downwardly from the frame. A plurality of outwardly projecting tabs are formed in the locking ring and are adapted to engage the manhole frame to prevent upward movement of the riser. An expansion device expands the frame and locking ring outwardly whereby the locking ring abuttingly engages a vertical surface of the manhole frame to assist in locking the riser assembly to the manhole frame.

Abstract: The invention relates to a device and method for sealing a manhole structure. An elastomeric band with at least two different peripheries is sealingly engaged to at least two corresponding peripheries of the manhole structure. Adhesives and supplemental retaining bands may also be used to secure the elastomeric band to the manhole structure.

Abstract: Existing street sewers consist of an immobile concrete structure supporting a frame. The present invention, the self-leveling street sewer, comprises a frame that floats on the foundation of the street and a tubular section that is connected to the connecting conduit. Since the frame is supported only by the street foundation, the immobile concrete structure is no longer required.

Abstract: An apparatus for adjusting the height and inclination of roadway and greenway appurtenances includes a rigid annular support ring mountable onto a rigid annular spacer ring sized so as to be mountable onto a manhole and a manhole frame mountable onto the support ring. The manhole frame is substantially frusto-conically shaped. A rigid annular base flange may be mounted around a base end of the manhole frame. A plurality of threaded bores are formed in spaced array around the base flange. Rigid elongate threaded members are threadably mountable into the threaded bores so as to be selectively threadably adjustable in the threaded bores and so as to protrude downwardly from the base flange into engagement, beneath the manhole frame, with a top surface of the support ring when the manhole frame is mounted on the support ring. The threaded members are threadably adjustable in the threaded bores to elevate or to tilt the manhole frame relative to the support ring.

Abstract: A utility access device and method includes telescoping, elongated upper and lower sleeves with an inclined upper edge. An angled ring is rotatably disposed on the inclined upper edge and has upper and lower opposite edges forming an inclined angle. The angled ring can be rotated to achieve a desired angle. A cover is removably disposed on the angled ring. An enlarged portion can be formed on the lower sleeve to straddle a utility, such as a valve.

Abstract: An adjustment riser is disposed between a manhole and a frame embedded in the paved surface of a roadway. The adjustment riser includes an annular concrete base which includes substantially flat top and bottom surfaces. A ridge and a groove are formed on the top and bottom surfaces, respectively, of the base to facilitate in the stacking of multiple risers and to prevent water infiltration. The adjustment riser additionally includes a plurality of adjustable support assemblies for supporting the frame. Each support assembly includes a support which extends axially within a corresponding bore formed in the base. Each support includes an enlarged head shaped to support the frame, the vertical position of the head of the support relative to the top surface of the base being continuously adjustable. In this manner, the adjustable nature of each support enables riser to hold the frame in its proper orientation relative to the paved surface.

Abstract: An adjusting device for installing a manhole ring onto a manhole is provided. The manhole has an annular inner shoulder. The adjusting device comprises a center plate and at least one supporting arm. Each supporting arm has a first end and a second end with the first end of the supporting arm being securable to the center plate. A securement assembly associated with the center plate releasably holds the manhole ring.

Abstract: A device for equalizing changes in level between a ground area surface extending over a ground structure and a frame for closure of an installation projecting into a ground structure therebelow, comprises a plate-shaped dragging body connected to the closure frame and projecting horizontally into the ground structure below a carrying layer thereof so as to transfer the change in level to the closure frame, the plate-shaped dragging body being a separate structural element which supports the closure frame on an upper side thereof.

Abstract: An apparatus for adjusting the height and inclination of roadway and greenway appurtenances includes a rigid annular spacer ring sized so as to be mountable onto a manhole, and a manhole riser mountable onto the spacer ring. The riser substantially frusto-conically shaped. A rigid annular base flange may be mounted around a base end of the riser. A plurality of threaded bores are formed in spaced array around the base flange. Rigid elongate threaded members are threadably mountable into the threaded bores so as to be selectively threadably adjustable in the threaded bores and so as to protrude downwardly from the base flange into engagement, beneath the riser, with a top surface of the spacer ring when the riser is mounted on the spacer ring. The threaded members are threadably adjustable in the threaded bores to elevate or to tilt the riser relative to the spacer ring.

Abstract: An adjustable utility access device and method includes a pair of angled rings disposed between a utility and a cover. The angled rings can include a frame and a rotatable ring. A angular scale can be disposed on one of the rings to indicate the angle formed by the rings. An orientation scale can be disposed on one of the rings to align the orientation of the angle. Two rotational settings can be determined based on measurements of the utility to allow the rings to be properly rotated and aligned.

Abstract: A mat is disposed on top of an access cover to compensate for a vertical offset between the top of the cover and the top of the roadway surrounding the cover. Fasteners are inserted through aligned holes in the mat and the cover and anchored in place in such a manner that the heads of the fasteners do not protrude above the top of the cover.

Abstract: A utility access device and method includes telescoping, elongated upper and lower sleeves with an inclined upper edge. An angled ring is rotatably disposed on the inclined upper edge and has upper and lower opposite edges forming an inclined angle. The angled ring can be rotated to achieve a desired angle. A cover is removably disposed on the angled ring. An enlarged portion can be formed on the lower sleeve to straddle a utility, such as a valve.

Abstract: A method and a device for safely and efficiently adjusting the height of a manhole freely allowing the addition and removal of a height adjusting member at any position. The method and device may be used for the manhole formed by installing a tubular shaped frame in the ground, installing the removable height adjustment members on the tubular shaped frame, and installing a cover receiving frame on the height adjusting members. In this method and device, a frame is disposed in the upper space of the manhole; the cover receiving frame is raised by the member installed on the frame; and the height adjusting members positioned under the cover receiving frame in that state are added or removed.

Abstract: An apparatus for adjusting the height and inclination of roadway and greenway appurtenances includes a rigid annular spacer ring sized so as to be mountable onto a manhole, and a manhole riser mountable onto the spacer ring. The riser substantially frusto-conically shaped. A rigid annular base flange may be mounted around a base end of the riser. A plurality of threaded bores are formed in spaced array around the base flange. Rigid elongate threaded members are threadably mountable into the threaded bores so as to be selectively threadably adjustable in the threaded bores and so as to protrude downwardly from the base flange into engagement, beneath the riser, with a top surface of the spacer ring when the riser is mounted on the spacer ring. The threaded members are threadably adjustable in the threaded bores to elevate or to tilt the riser relative to the spacer ring.

Abstract: An adjustable manhole cover frame assembly suitable for mounting on a manhole basin upper section has an outer ring, capable of resting on the top surface of the upper section, and an inner ring engaging the outer ring by screw threads and having support for a manhole cover. The lower surface of the frame assembly has a part spherically curved surface resting on a similarly curved surface of the manhole basin upper section and which allows the orientation of the frame assembly to be adjusted. Also, the frame assembly itself may have parts with part spherical mating surfaces allowing an upper part to be adjusted for slope when the remainder of the frame assembly has been fixed.

Abstract: A manhole access for sewers. More particularly, the present invention relates to a manhole that is adjustable in height and/or pitch to allow the top of the manhole top section to conform to the pitch of a surrounding surface, such as a road. Specifically, there is a cover, configured to cover access to the manhole extension, and an adjuster, coupled between the cover and the manhole extension, designed to be positioned in multiple positioned that form an angle of the cover relative to a top edge of the manhole extension. The adjuster has a cover coupler, positioned on a top side of thereof, designed to releasably hold the cover; and manhole extension coupler, positioned on a bottom edge thereof, designed to hold the adjuster proximate to the top edge of the manhole extension.

Abstract: A hydraulically adjustable manhole ring including upper and lower rings formed to provide a channel there between. The channel is sealed by in inner flexible membrane coupled between the inner circumferences of the upper and lower rings and an outer flexible membrane coupled between the outer circumferences of the upper and lower rings. A flowable setting agent is injected into the channel causing the upper ring to move relative to the lower ring.

Abstract: Existing street sewers consist of an immobile concrete structure supporting a frame. The present invention, the self-leveling street sewer, comprises a frame that floats on the foundation of the street and a tubular section that is connected to the connecting conduit. Since the frame is supported only by the street foundation, the immobile concrete structure is no longer required.

Abstract: A manhole/handhole includes a cover and a frame base. A plurality of elastic fixtures are bonded below through holes of the frame base. The through holes are corresponding to fixing holes of the cover so that screw bolts pass through the fixing holes of cover and the through holes of frame base and are locked to the fixtures. The cover is combined with the frame base so as to prevent the cover from jumping. Besides, at least a heightening base is installed between the cover and the frame base. The heightening base is stacked on the frame base so that the manhole/handhole is leveled with road surface for economizing working and time of roadwork.

Abstract: The invention relates to a device for covering shafts of manholes in roads, comprising a tube (3) which is slideably guided in a covering ring (2) that is rigidly fixed on the shaft (1) proper, and a retaining ring (4) for receiving the shaft cover positioned in the plane of the road surface (6). Flexible fastening and simple construction is obtained by mounting the retaining ring (4) on the tube (3) so as to be detachable, with a limited degree of movement.

Abstract: This invention relates to height adjustable extensions of in-ground containers for embedded container light supports in airport runways. The apparatus has a first and second telescoping tube, each having a wall terminating in a flange. The flange on its upper end is for the reception of a light fixture, and the flange at the bottom end has bolt holes registering with the flange on the upper end of the in-ground container. There are a plurality of tapped bores in the wall of the outer tube. Set screws in the tapped bores are adapted to bear on the inner tube. The method of extending the height of the lighting fixture container comprises these steps: providing the apparatus as described above, positioning the telescoping tubes at a required height position; tightening the set screws to temporarily preserve the height position; pouring cementitious material around the positioned tubes; and allowing the cementitious material to set to hold said tubes in place.

Abstract: An assembly for adjusting the elevation of a structure such as a manhole or a catch basin to be surrounded by pavement. A one-piece is formed to be inserted between a base rim and a cover of the structure. A lower member of the adapter is received in the base rim to be supported on an internal shoulder. An upper member extends outwardly of the lower member to receive the cover and upwardly to engage the upper end of the base rim and form an upward extension of the rim. The elevation of the structure may be increased by inserting the adapter between the base rim shoulder and the cover and decreased by removing the adapter from between the base rim shoulder and the cover. Additional adapters of identical construction may be inserted to further increase the elevation of the structure, all the adapters being nestable within one another.

Abstract: An adjustable utility access device and method includes a pair of angled rings disposed between a utility and a cover. The angled rings can include a frame and a rotatable ring. A angular scale can be disposed on one of the rings to indicate the angle formed by the rings. An orientation scale can be disposed on one of the rings to align the orientation of the angle. Two rotational settings can be determined based on measurements of the utility to allow the rings to be properly rotated and aligned.

Abstract: A manhole installation is provided that permits the height of manhole openings to be easily adjusted when road or ground surface levels have changed. The manhole installation comprises concentric manhole tube members that can be raised or lowered relative to each other are provided. The concentric tube members are each furnished with cooperating elements which, when engaged with each other, permit a graduated raising or lowering of one tube member in relation to the other. Existing manhole installations can also be modified so that positioning the opening of such manholes with a repaired road surface is facilitated.

Abstract: A cover system in use with a pavement slab, a communicating and downwardly extending manhole tube extending from the slab. The system includes a substantially annular shaped and three dimensional frame, encased within the pavement slab and such that a top edge extending surface of the frame lies substantially flush with a corresponding top edge surface of the slab. The frame further includes an inwardly facing, annular extending and recessed ledge in communication with the manhole tube. A cover is seatingly engaged and supported upon the recessed ledge, such that an upper edge surface of the cover is substantially flush with the top edge extending surface of the frame. A plurality of locking fasteners are arrayed at an angle relative to a perpendicular axis extending through the cover and the frame.

Abstract: A road gully or inspection cover assembly comprises an outer frame having an upstanding outer wall and integrally formed support structure extending inwardly of the lower regions of the outer wall over part at least of the peripheral extent of the outer wall, a first temporary inner frame for location within the outer frame, the outer frame and the first temporary inner frame co-operating to support a cover for the assembly in a first, lowermost position associated with the base course level of the road, and a second inner frame which, on removal of the first inner frame from within the outer frame, can be located within the outer frame to support the cover at a higher position associated with the wearing course level of the road.

Abstract: A sealable manhole system having a weld ring, a cover with a gasket shaped to engage the weld ring, and a cam lever assembly. The cam lever assembly comprising includes a cam lever having a cam surface and a pivot aperture. A pivot pin is sized to engage the pivot aperture and has a screw aperture formed there through. A connector operatively attached to the weld ring and an adjustment screw passes through the screw aperture and engages the connector. The cover further includes a gasket channel with a neck and an internal shoulder formed above the neck. The internal shoulder further has a dimension wider than the neck and is oriented at an angle to the neck.

Abstract: This concerns a sealing device that ensures the hermetic securing of the lid (5) in the access mouth (2) in order to prevent any infiltration of fluids from the outside or escape of gases from the interior.

Abstract: A hydraulically adjustable manhole ring including upper and lower rings formed to provide a channel there between. The channel is sealed by in inner flexible membrane coupled between the inner circumferences of the upper and lower rings and an outer flexible membrane coupled between the outer circumferences of the upper and lower rings. A flowable setting agent is injected into the channel causing the upper ring to move relative to the lower ring.

Abstract: A manhole access for sewers. More particularly, the present invention relates to a manhole that is adjustable in height and/or pitch to allow the top of the manhole top section to conform to the pitch of a surrounding surface, such as a road. Specifically, there is a cover, configured to cover access to the manhole extension, and an adjuster, coupled between the cover and the manhole extension, designed to be positioned in multiple positioned that form an angle of the cover relative to a top edge of the manhole extension. The adjuster has a cover coupler, positioned on a top side of thereof, designed to releasably hold the cover; and manhole extension coupler, positioned on a bottom edge thereof, designed to hold the adjuster proximate to the top edge of the manhole extension.

Abstract: A manhole assembly for below ground liquid storage tanks, such as fuel storage tanks, that includes securing the upper region of the below-grade manhole to the at-grade manhole so that lowering of the below-grade manhole bottom due to tank settling or stepping on the hatch cover will not lower the below-grade rim relative to the at-grade ring. Riser pipe extenders can be added without interfering with hatch cover closure and sealing of the below-grade manhole. One embodiment includes adjustable length bolts tying the at-grade ring to the below-grade ring. The assembly can be factory assembled, delivered to the site, and installed on the riser pipe then height adjusted before pea gravel, backfill, and concrete are poured. Bellows and bucket manholes can be used.

Abstract: The present invention relates to a height adjustable utility access device, such as a manhole, which adjusts in height to allow a top of a cover to sit flush with the surrounding surface, such as a road. The device has a cover which covers access to the utility; a frame coupled over the utility; and an adjuster, coupled between the cover and the frame, for adjusting the height of the cover relative to the frame. The adjuster can include an adaptor ring on the frame, and an extension ring on the adaptor ring. The extension ring can have tabs which selectively engage a plurality of steps on the adaptor ring. Alternatively, the steps can be formed directly in the frame. Alternatively, first and second rings can be disposed between the frame and cover. The rings can have meshing steps.

Abstract: The present invention relates to a device and method for adjusting a height and an angle of a cover for a utility access, such as a manhole, to allow a top of the cover to sit flush with the surrounding surface, such as a road. The device has a cover which covers access to the utility; a frame coupled over the utility; an adjuster, coupled between the cover and the frame, for adjusting the height and angular orientation of the cover relative to the frame. The adjuster can include an adaptor ring on the frame, and an extension ring on the adaptor ring. The extension ring can have tabs which selectively engage a plurality of steps on the adaptor ring. The adaptor ring and frame can have mating, angled edges with rotatably engage to adjust the angular orientation as the adaptor ring is rotated with respect to the frame. The angular orientation of the cover can be adjusted by rotating the angled edges, or the adaptor ring and frame, with respect to one another.

Abstract: An assembly for adjusting the elevation of a structure such as a manhole or a catch basin to be surrounded by pavement. A one-piece is formed to be inserted between a base rim and a cover of the structure. A lower member of the adapter is received in the base rim to be supported on an internal shoulder. An upper member extends outwardly of the lower member to receive the cover and upwardly to engage the upper end of the base rim and form an upward extension of the rim. The elevation of the structure may be increased by inserting the adapter between the base rim shoulder and the cover and decreased by removing the adapter from between the base rim shoulder and the cover. Additional adapters of identical construction may be inserted to further increase the elevation of the structure, all the adapters being nestable within one another.

Abstract: A manhole cover cap, for an access cover of an opening into an underground utility structure, can be used to raise the level of an access, or manhole, cover, and to prevent water inflow. The cover cap includes upper and lower opposed surfaces and an outer edge having dimensions substantially conforming to dimensions of the opening, adapted for attachment to the access cover, and comprises a rubber material.

Abstract: A manhole head assembly for mounting a cover on a manhole column is disclosed. The manhole head assembly comprises a support member having a top portion made of a grindable material and a bottom portion shaped and sized to rest on the manhole column. The top and bottom portions form an inner shoulder sized and shaped to receive the cover. The manhole head assembly further comprises at least one removable spacer adapted to be disposed between the shoulder and the cover for adjusting the height thereof.

Abstract: Assemblies and methods are provided to divert liquids that would otherwise infiltrate utility manholes or other hatchways, while allowing gases to vent to the atmosphere. Preferred embodiments of the assemblies comprise a cover support frame, a sheet of water-repellent gas-permable material occluding the central opening of the support frame and a cover mated to the frame. Preferably, a stiffening ring or other means of providing structural rigidity to the venting structure is provided. The assemblies are lightweight and are simple to install, and can be fabricated from materials that are readily available. Moreover, the assemblies can be easily modified to accommodate field conditions.

Abstract: A manhole access for sewers. More particularly, the present invention relates to a manhole that is adjustable in height and/or pitch to allow the top of the manhole top section to conform to the pitch of a surrounding surface, such as a road. Specifically, there is a cover, configured to cover access to the manhole extension, and an adjuster, coupled between the cover and the manhole extension, designed to be positioned in multiple positioned that form an angle of the cover relative to a top edge of the manhole extension. The adjuster has a cover coupler, positioned on a top side of thereof, designed to releasably hold the cover; and manhole extension coupler, positioned on a bottom edge thereof, designed to hold the adjuster proximate to the top edge of the manhole extension.

Abstract: The present invention relates to a device and method for adjusting a height and an angle of a cover for a utility access, such as a manhole, to allow a top of the cover to sit flush with the surrounding surface, such as a road. The device has a cover which covers access to the utility; a frame coupled over the utility; and adjusting means, coupled between the cover and the frame, for adjusting the height and angular orientation of the cover relative to the frame. The adjustment means can include an adaptor ring on the frame, and an extension ring on the adaptor ring. The extension ring can have tabs which selectively engage a plurality of steps on the adaptor ring. The adaptor ring and frame can have mating, angled edges with rotatably engage to adjust the angular orientation as the adaptor ring is rotated with respect to the frame. The angular orientation of the cover can be adjusted by rotating the angled edges, or the adaptor ring and frame, with respect to one another.

Abstract: The present invention relates to a height adjustable utility access device, such as a manhole, which adjusts in height to allow a top of a cover to sit flush with the surrounding surface, such as a road. The device has a cover which covers access to the utility; a frame coupled over the utility; and an adjusting means, coupled between the cover and the frame, for adjusting the height of the cover relative to the frame. The adjustment means can include an adaptor ring on the frame, and an extension ring on the adaptor ring. The extension ring can have tabs which selectively engage a plurality of steps on the adaptor ring. Alternatively, the steps can be formed directly in the frame. Alternatively, first and second rings can be disposed between the frame and cover. The rings can have meshing steps.

Abstract: An assembly for adjusting the elevation of a structure such as a manhole or a catch basin to be surrounded by pavement. A one-piece is formed to be inserted between a base rim and a cover of the structure. A lower member of the adapter is received in the base rim to be supported on an internal shoulder. An upper member extends outwardly of the lower member to receive the cover and upwardly to engage the upper end of the base rim and form an upward extension of the rim. The elevation of the structure may be increased by inserting the adapter between the base rim shoulder and the cover and decreased by removing the adapter from between the base rim shoulder and the cover. Additional adapters of identical construction may be inserted to further increase the elevation of the structure, all the adapters being nestable within one another.

Abstract: A fiberglass manhole adjustment ring comprising a fiberglass pipe and a self-centering lip attached to the edge of the pipe, and a method for installing the fiberglass manhole adjustment ring in an existing fiberglass manhole. The self-centering lip can either be attached to the interior edge of the pipe to form a sleeve or to the exterior edge of the pipe to form a collar. An interior self-centering lip, or sleeve, slides into an adjoining fiberglass manhole section while an exterior self-centering lip, or collar, slides over an adjoining manhole section. The manhole adjustment ring is inserted between the cone section and barrel section of an existing fiberglass manhole to accommodate changes in elevation of the surrounding grade level. The self-centering lip may also be used on manhole sections to enable field assembly of a manhole.

Abstract: A resilient, replaceable insert made from an elastomeric material that protects vehicular traffic from damaged caused by a roadway structure, such as manholes, catch basins and utility access conduits, when the roadway structure is recessed below the roadway pavement. The insert has a shape sized to accommodate the roadway structure it protects and provides a smooth transition for vehicular traffic traveling along the roadway and over the roadway structure. The resilient, replaceable insert further provides a low cost means for protecting vehicular traffic from the recessed roadway structure that may be easily installed with limited manpower and without the need for additional equipment.

Abstract: Apparatus for provisionally covering an inspection shaft during surface pavement with asphalt or concrete, includes a cover plate formed with a central breakthrough and a centering device arranged on the bottom side of the cover plate for securing the cover plate in the inspection shaft. A pipe is received in the breakthrough for axial displacement and has an end face for attachment of a flange. The pipe can be closed by a detachable lid. After depositing a first layer of the pavement, the area of the pipe above the lid is cleared manually, and the lid is removed for subsequent elevation of the pipe to a level in which the flange is disposed above the first layer of the pavement. The elevated area of the pipe is backfilled so that the flange can rest upon the first layer before closing the lid and applying a next layer of the pavement.

Abstract: A steel manhole is provided which includes a steel box having a hole having a bolt hole and formed at an upper portion of the same, a height control pipe having a vertical longitudinal hole inserted into an inner diameter portion of the hole, a multi-hole lid for covering an upper portion of the height control pipe, a male screw formed at left and right portions of the steel box and having a male screw portion, and a female screw having a thread portion for being threaded with the male screw pipe.

Abstract: A manhole cover mounting structure includes an outer frame fastened to a manhole box by screw bolts, the outer frame having an upright guide rod in each of a plurality of hollow peripheral locating blocks thereof, an inner frame adjustably fastened to the inner frame to hold a cover plate in flush with the road surface. The inner frame has a plurality of female screws fastened to peripheral lugs thereof to hold a respective hollow screw rod for the mounting of through bolts; thereby securing to secure the inner frame to the upright guide rod in each locating block of the outer frame.