Meter box lid with snap fit passage

The lid is used to cover a utility box which houses a meter such as a water meter. The lid is compression molded from a plastic material such as medium density polyethylene, and has a planar upper surface and a planar lower surface. In one embodiment, a plurality of generally parallel spaced apart recesses are formed in the lower surface. The recesses are spaced inward of the outer edges of the lid. The area of the lower surface of the lid is greater than the total area of the recesses in the plane of the lower surface. In another embodiment, an opening leading to a cavity is formed in the edge of the lid with a press fit passage for receiving a transponder device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a removable lid for covering a utility box such as a water meter box.

2. Description of the Prior Art

In the past, utility boxes such as water meter boxes have been made of concrete or plastic with lids formed of the same material. U.S. Pat. Nos. 2,883,853, 4,163,503, 4,726,490, 5,423,448, 5,394,601, and 5,791,098 disclose different types of lids.

Meter box lids also have been employed for holding transponder devices for enabling personnel to read water meters from a distance without leaving the utility truck. One transponder device used comprises a disc for supporting an electromagnetic receiver and transmitter apparatus and a stem attached thereto for enclosing components to be attached to the meter. Some of the lids are formed of concrete or plastic and have a slot molded in its outer edge for holding the transponder device.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a new and useful, strong, heavy duty lid for a utility box and which may be used on concrete or plastic boxes. The lid in one embodiment comprises a member formed of a plastic material with elongated recesses formed in the lower surface which minimizes breakage of the lid. The recesses are spaced inward of the outer edges of the lid member. The recesses are generally parallel to each other and have lengths equal to a substantial portion of the length of the lid along which the recesses extend.

It is a further object of the invention to provide a lid for a utility box which has a cavity formed in its edge which defines a lower wall for supporting the disc shaped housing of a transponder device of the type having a stem connected to the housing. The lower wall has an opening in communication with the cavity and a smaller passage for receiving the stem of the transponder device. At least one edge of the passage is resilient which allows the stem to be pushed through the passage into the opening. The edge of the passage then returns to its normal state to hold the stem in the opening and hence the housing in the cavity during the intended use.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now toFIGS. 1–10of the drawings there is shown four lids21,21M,61, and61M which are compression molded from a suitable plastic material such as medium density polyethylene. Referring toFIGS. 1,2,9and10, the lid21comprises an upper side having a flat or planar upper surface21U and a lower side having a flat or planar lower surface21L. The upper and lower sides are rectangular with four edges21A,21B,21C, and21D. Formed in the lower surface21L during the molding operation are two identical elongated, parallel recesses23and two identical, square recesses27and29. The recesses23have outer edges23A,23B,23C,23D. The recess27has outer edges27A,27B,27C,27D. The recess29has outer edges29A,29B,29C,29D. Formed in the upper surface21U during the molding process are two identical, circular recesses31and33which are generally aligned with the two square recesses27and29respectively. Also formed on each edge21A,21B,21C and21D are two spaced apart wedges37or lugs which extend outward from the upper surface21U and taper downward to the lower surface21L. The wedges37may be shaved or cut to the desired shape in order to allow the lid to fit into the top opening of the utility box. Also molded or drilled through the lid21is a finger hole39for gripping purposes to more easily allow the lid to be fitted to or removed from the utility box.

The purpose of the recesses23is to minimize breakage of the lid and the purpose of the recesses27,29and31,33is to receive remote reading equipment in the interior of the utility box and on the top of the lid21. Apertures will be formed through the lid to provide an opening between the recesses27and31and to provide an opening between recesses29and33to allow connection between the interior and exterior equipment.

Lids similar to lid21were produced but they did not have the recesses23. If these lids were dropped on a hard surface, the lids would crack in some instances. Also when a high vertical pressure was applied to the lids when they were supported at the outer edges, they would break. The problem was solved however, by forming the recesses23during the molding process. The lid ofFIGS. 1,2,9,10was tested by dropping it on a hard surface and by applying a high pressure to its upper surface21U with the outer edges of its lower surface21L supported by means and the lid did not crack or break. It is believed that the improved results were obtained since the recesses23allowed a better heat transfer of the hot flowable plastic during the molding process and they enhanced curing of the plastic. The recesses27and29have solved the prior problem at least on the side of the lid on which they are located. The area of the lower surface21L is greater than the total area of the recesses23,27, and29in the plane of the surface21L.

Referring toFIGS. 3 and 4, the lid21M is similar to lid21except that it does not have recesses27,29,31,33; or the opening39; it has an opening43formed through the lid at its central portion with a cover45hinged to the upper surface21U to allow manual reading of the meter in the utility box and it has three identical excesses23. InFIGS. 3 and 4, the same reference numerals as used inFIGS. 1,2,9, and10identify the same components and except for the differences mentioned above. The dimensions of lid21M are the same as lid21. Referring toFIG. 4, the outer recesses23are spaced about 2½ inches from the central recess23. The opening43may have side dimensions in inches of 3¾×6⅞. The lid21M is compression molded from a plastic material such as medium density polyethylene.

Referring toFIGS. 5 and 6, the lid61is compression molded from a suitable plastic such as medium density polyethylene. It is similar to lid21M except that it is longer; it does not have the central opening43; it has 4 spaced recesses23and five spaced rows of circular recesses63in its lower side. The lid61has a flat or planar upper surface61U, a flat or planar lower surface61L; edges61A,61B,61C,61D; and wedges67. The length, width, and height of the lid61in inches may be 26½, 15, and 1½ respectively. The recesses23have the same dimensions as recesses23ofFIGS. 1 and 2. In the embodiment ofFIGS. 5 and 6, adjacent recesses23may be spaced 3 inches apart. The round recesses63may have a diameter of 2¼ of an inch and a depth of ¾ of an inch. Recesses63help perform the function of recesses23.

Apertures65and67extend through the lid61and are used as a touch read hole for use for reading the meter in the box and as a finger hole respectively.

Referring toFIGS. 7 and 8, the lid61M is compression molded from a suitable plastic material such as medium density polyethylene. The lid61M is similar to the lid61except that it has a central opening71with a hinged cover73for use for manual reading of the meter in the box. Apertures65and67are not employed and have in their place two circular recesses63. InFIGS. 7 and 8, the same reference numerals identify the same components as shown inFIGS. 5 and 6. The dimension of the lid61M may be the same as those of lid61.

In the embodiment ofFIGS. 1–10the lengths of the recesses23are equal to a substantial portion of the length of the lid along which the recesses extend and are greater than one half of said lengths of the lid and are a little greater than ¾ of said lengths of the lid. For each lid, the area of the lower surface also is greater than the total area of the recesses23in the plane of the lower surfaces of the lid.

The median density range of the polyethylene used in forming the lids ofFIGS. 1–10is 0.938–0.942.

Compression load tests were carried out on the lid ofFIGS. 1–6,9,10and on the lid ofFIGS. 7 and 8. The tests were performed utilizing a 9″×9″ steel plate placed on the lid center. Prior to testing, each sample was placed on steel blocks around the perimeter of the lid to simulate the lip of the meter box.

Tests were performed on three lids of the embodiment ofFIGS. 1–6,9,10. The three lids tested withstood a total load in pounds of 9380; 12,230; 8,910, respectively.

The lid ofFIGS. 7 and 8had a length of 26 inches and a width similar to that of lid61. Tests were performed on two lids of the embodiment ofFIGS. 7 and 8. The two lids tested withstood a total load in pounds of 14,070; 12,070, respectively.

It appears that the lid ofFIGS. 7 and 8withstood a greater load since it did not have the recesses27,29,31,33of the lid ofFIGS. 1–4,9,10.

The lids described with respect toFIGS. 1–10are all rectangular in shape. The plastic lids however may be circular or oblong in shape with planar upper and lower surfaces. All of the lids ofFIGS. 1–10have at least two parallel recesses23formed in their lower surfaces. The lengths of at least one of the recesses23will be equal to a substantial portion of the length of the lid along which the recess extends and greater than one half of said length of the lids. In addition, the area of the lower surface greater than the total area of the recesses23in the plane of the lower surfaces of the lid.

Referring now toFIGS. 11–21, the lid is identified by reference numeral121. It is compression molded from a suitable plastic material such as median density polyethylene. The lid comprises an upper side having a flat or planar upper surface121U and a lower side having a flat or planar lower surface121L. The upper and lower sides are rectangular with four edges121A,121B,121C,121D. Formed in the lower surface during the molding process are three parallel recesses123,125,127. The recess123has four edges123A,123B,123C,125D at the surface121L. The recess125has four edges125A,125B,125C,125D at the surface121L. The recess127has four edges127A,127GB,127C,127D at the surface121L. Formed on each of edges121A and121C are wedges or lugs137which extend outward from the upper surface121U and taper downward to the lower surface121L as seen inFIG. 21. The wedges137may be shaved or cut to the desired shape in order to allow the lid to fit into the top opening of the utility box. Also drilled through the lid121is a finger hole139for gripping purposes to more easily allow the lid to be fitted to or removed from the utility box.

The purpose of the recesses123,125,127is to enhance curing of the plastic during the forming process and hence to minimize breakage of the lid as discussed previously with respect to the lids ofFIGS. 1–10. It is believed that improved results were obtained since the recesses allowed a better heat transfer of the hot flowable plastic during the molding process and enhanced curing of the plastic.

The inside surfaces of the recesses are formed in a manner to strengthen the lid. In this respect surfaces123S1,123S2;125S1,125S2;127S1,127S2form triangles. Surfaces123S3,123S4;125S3,125S4;127S3,127S4form trapezoids. The four surfaces of each recess123,125,127slant upward from the lower surface121L and meet at the three apexes123AP,125AP,127AP respectively and act to provide support and strengthen the lid even though the recesses result in less lid material. Recesses125and127are shaped in a manner similar to that of recess123except recess127is longer than recess123.

In one embodiment, the length of each of the edges123A,123C,125A,125C,127A,127C is about two inches. The length of each of edges123B,123D,125B,125D is about 6½ inches. The length of edges127B,127C is about 13.5 inches. The height of each of the recesses123,125,127from the surface121L to their apexes123AP,125AP,127AP is about 14/16 of an inch. The width W and length L of the lid121are about 10 and 14.75 inches respectively. The height H of the lid121is about 1.75 inches.

The total surface area of the lower side121L outside of the recesses123,125,127and outside of the opening141,151,157,159is greater than the area of the recesses123,125,127and the opening141,151,157,159in the plane surface121L. The lid121between the surfaces of recesses123,127, and most of125and the upper surface121U is solid plastic.

An opening141extends inward below the upper surface121U from the two edges121C and121D to a cavity141C which is the only cavity formed in the lid. The opening141comprises an upper wall143, having a rounded side wall145extending from edges121C and121D and a lower wall147which forms a shelf. The cavity141C is defined by the walls145and147and an interior partially circular wall141CC. The lower wall147has an opening151defined by wall portions153A and155A which extend inward from edges121C and121D and lead to side walls153B and155B defining a passageway157which leads to a stem opening159. The purpose of the cavity141C is to receive the housing of a transponder device to be supported by the shelf147with the stem of the transponder device extending downward through the stem opening159. A transponder device of this type is shown at161atFIGS. 15,16,17and18. The housing is a disc shaped housing member163having an upper central wall portion165formed of plastic, an outer upper wall portion167formed of metal, a bottom wall portion169formed of metal, and an elongated annular stem171formed of metal extending downward from the bottom wall169. The diameter of the stem171tapers slightly from the wall169to its end171E. A transponder device of this type is commercially available from Itron, Inc. as disclosed in U.S. Pat. No. 6,218,995B1 which patent is incorporated herein by reference.

The purpose of the transponder device is to read the output of i.e. a water meter located in the ground in the meter box which supports the lid. Electrical leads extend downward through the stem171. Equipment powered by a battery will read the output of the water meter and transmit its output to the equipment in the housing when activated. Reading can be accomplished by sending a radio signal for example from a vehicle on the road to activate the transponder device which in turn will send a signal to the equipment in the vehicle to obtain a record of the amount of water used by the homeowner or business during the month. Since the lid121is formed of plastic, the transponder device can receive and transmit electromagnet signals through the plastic.

It is desirable that some means be provided to hold the transponder device in the cavity. Moreover, the manufacturer of the transponder device has indicated that the upper side165of the transponder device should be located at least ⅛ of an inch below the surface of the wall143of the cavity141. A separate wedge could be used to wedge the transponder device in the cavity, however, this is undesirable since it is one more thing that field personnel would have to carry in locating and holding the transponder device in the cavity. In addition, the installer may push the wedge in with too much force and damage the transponder and the wedge in place may apply to much pressure to the transponder and damage or alter the performance of the transponder.

A snap or pressure fit is provided for holding the base171of the transponder device161in the opening159and hence the housing163of the transponder device161in the cavity141C. This is accomplished by forming thin lips153BL and155BL at the side edges153B and155B at the bottom shelf on each side of the passageway which are flexible and resilient. The normal width PW of the passageway157at the lips153BL and155BL is slightly less than the diameter of the stem171at the level of the lips such that the stem171can be manually pushed through the passageway157moving the lips153BL and155BL aside or out of the way to allow the stem to be located in the opening159. The lips153BL and155BL then will move inward toward each other to retain their original state or position normally preventing the stem171from moving out of the opening159. Thus the stem171is held in the opening159and the shelf147supports the housing163in the cavity141C below the upper wall143(during its intended use) in accordance with the manufacturer's recommendations. The transponder device161may be removed by pulling the stem171through the passageway157to force the flexible or resilient lips153BL and155BL out of the way allowing the stem171to be removed from the stem opening159and the housing163out of the cavity141C.

For the stem171having a diameter of about 1.75 of an inch at the level of the lips153BL and155BL, the passageway157may have a quiescent or at rest width PW (SeeFIG. 11) of about 1 11/16 of an inch. For the wall174(formed of medium density polyethylene) having a thickness Z1 about ⅜ of an inch, each lip153BL,155BL has an at rest dimension Z2 of about 2.5/16″ and an at rest dimension X of between about 1/32″ and ⅙″ (SeeFIG. 19). The lips extend to a thin line at153BL at the top level of the shelf174. Referring toFIG. 11, the dimension Y is about ½″. By pushing the stem through the passageway157against the lips153BL and155BL, the lips will be pushed out of the way, as shown in dotted lines inFIG. 19, allowing the housing to be inserted into or removed from the opening after which the lips153BL and155BL will return to their quiescent state. For a transponder161having a housing or head outside diameter of 6¾″ and a maximum housing height of about 11/16″, the diameter of the cavity41C will be a little greater than 6¾″, sufficient to easily receive the housing163, and its height may be about 15/16″. These dimensions may vary depending on the size of the transponder. The opening141, cavity141C, and the walls153A,155A,153B,155B, opening159, and the lips153BL and155BL are formed during the molding process, and touched up with a router bit if desired.

Referring toFIGS. 22 and 23, the lid is identified by reference numeral181. It is compression molded from a suitable plastic material such as medium density polyethylene. The lid comprises an upper side having a flat or planar upper surface181U and a lower side having a flat or planar lower surface181L. The edge of the lid comprises a surrounding flange187with a lower edge189spaced inward from the outer edge187E of the flange187. The lower edge189has two straight sides189A and189B and two rounded sides189B and189C. The flange187comprises two straight portions187EA and187EB and two rounded portions187EC and187ED.

The lid181is small in area within the edges187E and189and has a single recess201formed in its lower side181L during the molding process to enhance curing of the plastic material during the forming process and hence to minimize breakage of the lid. The recess201is similar to either of recesses123,125,127but it has different dimensions. In this respect the recess201has two trapezoid sides201S1and201S2and two triangular shaped sides201S3and201S4which flare outward to the surface187L from an elongated apex201A. The lid181between the surfaces of recess201and the top surface is solid plastic.

An opening241extends inward below the flange187from the side189D to a cavity241C which is the only cavity formed in the lid. The opening241comprises an upper wall243, extending from side189D and a lower wall247which forms a shelf. The cavity241C is defined by walls243and247and wall241CC. The lower wall247has an opening251defined by wall portions253A and255A which extend inward and lead to side walls253B and255B defining a passageway257which leads to a base opening259. The purpose of the cavity241C is to receive the housing of a transponder device of the type shown inFIG. 18. to be supported by the shelf247with the stem of the transponder device extending downward through the stem opening259with the top of the transponder device spaced from the wall243the desired amount.

A snap or pressure fit is provided for normally holding the stem171of the transponder device161in the opening259and hence the housing163of the transponder device161in the cavity241C in a manner similar with that of the embodiment ofFIGS. 11–21. This is accomplished by forming thin lips253BL and255BL in the side edges253B and255B at the bottom shelf on each side of the passageway which are flexible and resilient. The normal width of the passageway157at the lips253BL and255BL is slightly less than the diameter of the stem171at the level of the lips such that the stem171can be manually pushed through the passageway257moving the lips253BL and255BL aside which then will move inward toward each other to retain their original state or position normally preventing the stem171from moving out of the opening259during its intended use. Thus the stem171is held in the opening259which holds the head163in the cavity241C. The transponder device161may be removed or inserted by pulling or pushing the stem171through the passageway257to force the flexible lips253BL and255BL out of the way allowing the stem171to be inserted or removed into or from the opening259and the head165into or out of the cavity241C. The dimensions of the lips253BL and255BL may be similar to those of the embodiment ofFIGS. 11–21and may be spaced apart the same amount as those of the embodiment ofFIGS. 11–21.

A shallow half round recess261is formed in the lower surface181L to receive equipment. An aperture263is formed through the upper wall261of the recess261and hence through the lid.

The lid181between the surfaces of recess201and its upper surface is181U solid plastic. The total surface area of the surface181L outside of the recesses201and261and outside of the maximum lateral boundaries of the cavity241is greater than the areas of the recesses201and261in the plane of the surface181L. The opening241, cavity241C walls253A,255A,253B,255B, lips253BL,255BL and opening are formed during the molding process and touched up with a router bit if desired.

Referring toFIGS. 24–30, the lid401is formed of plastic material and is circular in shape, having a bottom side403and a top side405. The top side405and bottom side403are generally flat. The edge of the lid comprises a surrounding flange407with a lower edge409spaced inward from the outer edge407E of the flange407.

An elongated rectangular shaped recess421is formed in the lower surface403during the molding process. The recess421comprises two generally flat sides425and427which flare outward to the surface403from a center line429and two triangular shaped surfaces431and433which flare outward to the surface403from opposite ends of the line429. Each of the sides425and427is trapezoidal in shape and together they define an angle of about 90 degrees and form a triangle with the plane of the surface403as seen in the cross-section ofFIG. 30.

Also provided is an elongated rectangular shaped recess471which is formed in surface403. The recess471comprises two parallel elongated sides473and475A,475B and two parallel sides477and479. Sides473,475A,475B and477are perpendicular to the surface403. The recess471in cross-section as seen inFIG. 29, is saw-tooth in shape having two surfaces481and483which are oblique relative to the surface403and a surface485which is perpendicular relative to surface403. The lid401between the surfaces of recesses421and471and its upper surface405is solid plastic.

In addition, a recess491is formed in the surface403for holding a lock493.

In one embodiment, the diameter of the flange407is about 12⅜ inches and the diameter of the edge409and hence of the surface403is about 11 inches. The widths and depth of the recess421is about 1½ and ¾ inches respectively. The lengths of the recess421is about 8½. The length and width of the recess471are about 6¼ and 2½ inches respectively. The dimensions of the slanted surfaces481and483along the length of the recess471are about 1½ and 3½ inches and the vertical dimension of surface485is about 1/2  inches. The length and width of the recess491are about 3½ inches and 3 inches respectively. The thickness of the lid from surface403to surface405is about 1¼ inches. Two prongs495extend outward from surface403spaced from the flange407.

Formed in the edge409is an opening501which extends inward below the flange407and the top surface405to a rounded cavity501C which is the only cavity formed in the lid. The cavity501C is defined by a side wall503, the wall portion405A of the lid which is below the surface405which is level with the bottom of the flange407and a lower shelf505which follows the side wall503and extends a limited distance therefrom to define a shelf to removably hold a transponder device. The lower shelf505extends a limited distance to define an open portion507which leads to a central portion507C.

The opening507is defined by wall portions507A and507B which have thin flexible and resilient lips507AL and507BL which act in the same manner as lips153BL and155BL to allow passage of the stem171into the central portion507C of the opening507(by manually applying pressure to the stem) and hence the housing into the cavity501C to normally hold the housing163(during its intended use) of the transponder device in the cavity501C supported by the shelf505, spaced from the lid wall405A a sufficient amount and allows it to be removed by pressure applied thereto if desired.

On the top side405, shallow recess521is formed in the surface405and which coincides with the position of the opening501to allow an aperture to be formed through the lid at this position if desired to allow a signal receiver and transmitter to extend through the lid from the utility box if the utility company wants to use this type of meter reading facility.

The lid ofFIGS. 24–30is compression molded from a plastic material such as medium density polyethylene. The recesses421and471are formed during the molding process to enhance curing of the plastic during the forming process to minimize breakage of the lid. The lock493of the lid is attached after the molding process.

The opening501, cavity501C, opening507, walls507A,507B, and lips507AL and507BL are formed during the molding process, and touched up with a router bit if desired. The dimensions of the lips507AL and507BL may be similar to those of the embodiment ofFIGS. 11–21and spaced apart the same amount as those of the embodiment ofFIGS. 11–21.

Load tests were carried out on the lid ofFIGS. 11–21,22,23; and24–30in a manner similar to those described in connection with the lids ofFIGS. 1–10and the results were that the lid ofFIGS. 11–21withstood a load of 20,730 pounds; the lid ofFIGS. 22,23withstood a load of 20,675 pounds; and the lid ofFIGS. 24–30withstood a load of 8,565 pounds.