Abstract:
An adapter for a tank, having a bottom with one or more adhesive-receiving channels formed therein, an inner wall, structure for supporting a riser component on the adapter, and wall reinforcement structure. The adapter is particularly suited to providing pre-cast concrete tank lids with structural, interengaging support for a column of stackable riser components to form a passageway to facilitate access to the tank from a higher elevation.

Description:
BACKGROUND  
       [0001]     1. Field of the Disclosure  
         [0002]     This disclosure relates generally to stackable riser components for use in providing access to septic tanks and other on-site waste treatment or drainage systems and, more particularly, to adapters for use in providing an interface between, for example, a lowermost stackable riser component and a lid of a septic tank, other on-site waste treatment system, or drainage system, such as a lid made of concrete or similar material.  
         [0003]     2. Description of the Prior Art  
         [0004]     Stackable riser components have been used to facilitate access to septic tanks and other on-site waste systems, as well as to drainage systems. These tanks and other waste or drainage systems are usually buried underground, and the stackable riser components are used to form a passageway, typically extending from above an opening in a lid of the tank, up to a higher elevation, at or near grade level. In an effort to ensure a secure interface between a stack, or column, of riser components and a lid of a septic tank, waste system, or drainage system, a recommended practice is to cast a lowermost riser component directly in place into the lid, which lid is typically made of concrete.  
         [0005]     Those of ordinary skill in the art will understand that the term “concrete lid” or “lid” of the septic tank refers to the large, horizontally-oriented concrete slab, typically on the order of 4 feet by 8 feet, for example, provided at the top of the septic tank having a capacity from about 750 to about 1,250 gallons, and supported by the walls of the septic tank, as opposed to the term “concrete cover” or “cover,” which as used herein refers to the movable, generally smaller (and typically round) cover member conventionally associated with an opening in the concrete lid and used to gain access to the interior of the septic tank.  
         [0006]     By only following the recommended practice of casting a lowermost stackable riser component directly in place into a concrete lid, there is a predicament when one desires to securely interface a stack of riser components over a tank, sewage waste system, or drainage system having an already-cast concrete lid. As an alternative, there have been attempts at adapters that are intended to adhere to the top of the already-cast concrete lid. For example, Zabel Environmental Technology of Crestwood, Ky. offers adapters (as part of its Zeus™ Access System), such as the 20″ tank adapter top, Model #RB-TA-T-20x2, for use in retrofitting existing concrete tank lids. The square-based adapter, shown in cross-section in FIG. 1 of U.S. Pat. No. 6,047,724, has a bottom edge, and is intended to be secured to the concrete lid by applying mastic adhesive to the bottom edge of the adapter top, and pressed onto the top of the concrete lid. That particular prior art adapter is also provided with circumferentially-mounted lugs, intended to pass through slots provided in an inwardly extending flange of a downwardly extending skirt portion of a bottom portion of a lowermost riser of a column, or stack, of risers. Upon rotation of the lowermost riser, the lugs engage inclined stop portions provided in the flange of the lowermost riser, to thereby prevent rotation of that lowermost riser, and thus rotation of a stack of risers, relative to the adapter.  
         [0007]     Another adapter intended for installation on previously cast concrete tank lids is the riser adapter ring of Polylok Inc. of Yalesville, Conn. That riser adapter ring is currently available in a single size, having the capacity to fit both 20″ and 24″ diameter risers. A raised inner wall supports a 20″ diameter riser, with vertical ribs positioned on an inside surface of the inner wall. Some of the vertical ribs are provided with screw bosses, which are positioned to align with screw-receiving holes in the interior of a complementary 20″ or 24″ diameter riser. Screws are used to secure the lowermost riser of a column of risers to the riser adapter ring.  
         [0008]     The interior location of the screw bosses in the Polylok adapter ring exposes unprotected portions of the securement screws at the intersection of the adapter ring and lowermost riser to corrosive gases within the column of risers. It would therefore be desirable to position screw bosses on the exterior of an adapter ring, rather than on the interior, so as to better isolate securement screws from corrosive gases within a column of risers leading up from the adapter ring located on the lid of a septic tank. 
     
    
     DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING  
       [0009]      FIG. 1  is a perspective view of a portion of a concrete lid having an opening therein, an adapter ring of the present disclosure secured to the top of the lid, and a lowermost stackable riser component received on the adapter ring;  
         [0010]      FIG. 2  is a cross-sectional view, taken along lines  2 - 2  of  FIG. 1 , and with a cross-section of two additional stackable riser components stacked on the lowermost stackable riser component;  
         [0011]      FIG. 3  is a top view, partially cut away, of the adapter ring and concrete lid shown in  FIG. 1 , with a partial horizontal cross-section, taken along lines  3 - 3  of  FIG. 1 , of the stackable riser component stacked on the adapter ring;  
         [0012]      FIG. 4  is a top plan view of an adapter ring of the present disclosure;  
         [0013]      FIG. 5  is an upper elevational view of the adapter ring shown in  FIG. 4 ;  
         [0014]      FIG. 6  is a lower elevational view of the adapter ring shown in  FIG. 4 ;  
         [0015]      FIG. 7  is a bottom plan view of the adapter ring shown in  FIG. 4 ;  
         [0016]      FIG. 8  is an enlarged cross-sectional view of a lower left portion of  FIG. 2 , corresponding to the area identified by the broken line referenced as “ FIG. 8 ” in  FIG. 2 ;  
         [0017]      FIG. 9  is an upper elevational view of an alternate embodiment of the adapter ring;  
         [0018]      FIG. 10  is a cross-sectional view of a stack of three adapter rings of the type shown in  FIG. 9 ;  
         [0019]      FIG. 10A  is a cross-sectional view, broken away, of two adapter rings similar to the type shown in  FIG. 9 , and further provided with pins and pin-receiving recesses;  
         [0020]      FIG. 10B  is a cross-sectional view, broken away, of the two adapter rings shown in  FIG. 10A , and wherein the two adapter rings are stacked, with the pin of the lower adapter ring received in the pin-receiving recess of the higher adapter ring;  
         [0021]      FIG. 10C  is a lower elevational view, broken away, of an adapter ring of the type shown in  FIGS. 10A and 10B ;  
         [0022]      FIG. 11  is an exploded view of an adapter ring of the type shown in  FIGS. 1-8 , mounted on a concrete lid, in combination with a riser pan, a concrete cover received in a frustro-conical portion of the riser pan, a pair of stackable riser components, and a riser cover;  
         [0023]      FIG. 12  is an exploded view of an adapter ring of the type shown in  FIGS. 1-8 , mounted on a concrete lid, in direct combination with a riser cover, without any stackable riser components between the adapter ring and the riser cover; and  
         [0024]      FIG. 13  is a partially exploded view of an adapter ring of the type shown in  FIGS. 1-8 , mounted on an upper concrete riser situated on a lower concrete riser, in direct combination with a riser cover, without any stackable riser components between the adapter ring and the riser cover. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     With reference to the drawing figures, an adapter ring  10 , also generally referred to herein as an adapter, is shown ( FIGS. 1-3 ) in use as an interface between a concrete lid  12  of a septic tank or similar on-site waste disposal system or drainage system, and a lowennost stackable riser component  14 . The concrete lid  12  has an access opening or hole  16  therethrough, which could be round, square, or some other shape. This opening or hole  16  permits entry into the interior  17  of a septic tank or other on-site waste disposal system or drainage system for pumping, service, filter changing, inspection, and other maintenance.  
         [0026]     The adapter ring  10  has a bottom  18  with one or more channels  20  therein. These channels  20  advantageously increase the surface area of the adapter ring  10  that is exposed to adhesive material  22 , such as butyl mastic, by allowing the adhesive material  22  to creep up into the channels  20 , thereby improving the strength of the bond between the adapter ring  10  and the concrete lid  12 . The channels  20  also form water stops, i.e. upstanding obstacles water must negotiate over, making it more difficult for liquid to find a leakage path between the bottom  18  of the adapter ring  10  with adhesive  22  thereon, and the concrete lid  12 , and thus advantageously addressing a leakage problem known in the art as a “short circuit.” Notably, in order to avoid requiring excessive quantities of adhesive material  22  to fill the channels  20 , the width and depth dimensions of the channels  20  should be small relative to the bottom  18 . Generally, no more than half, and preferably a much smaller percentage, of the surface of the bottom  18  is occupied by channels  20 .  
         [0027]     A ratio of width-to-depth of the channels of no more than about 2:1, and preferably about 1:1, is optimal to achieve an acceptable bond between the adapter ring  10  and a concrete surface without the need for excessive quantities of mastic. Width and depth dimensions of the channels  20  in the range of about 0.05″ to about 0.1″ are preferred so as to achieve the desired width-to-depth ratios for the channel dimensions while avoiding the need for inordinately large adapters.  
         [0028]     The adapter ring  10  ( FIG. 6 ) includes an inner wall  24  extending upwardly from the bottom  18 . While the adapter ring  10  is shown to have a round inner wall  24 , other shapes, such as ellipsoidal, square, rectangular, or triangular, are possible, and are to be considered within the scope of the present disclosure. The shape of the inner wall  24  of the adapter ring  10  is selected to mate with a female end of a stackable riser component  14 , such that if the riser component  14  is round, the inner wall  24  of the adapter ring  10  is also round, but if a square or other-shaped riser were employed, a complementary-shaped inner wall  24  of the adapter ring  10  could be provided for use therewith.  
         [0029]     Riser leg support surfaces  26  projecting inwardly from the inner wall  24  are preferably provided. These riser leg support surfaces  26  may, for example, be tops of vertically-oriented inner rib members  28 , as shown in  FIGS. 5 and 6 . The inner rib members  28  preferably extend upwardly from a level even with the bottom  18 . If the adapter ring  10  is adhered to the concrete lid  12  in such a manner that the bottoms  30  of the inner rib members  28  are bonded by adhesive to the top of concrete lid  12 , then the inner rib members  28  will advantageously be able to transmit any vertical loads borne along their length and down to the concrete lid  12 .  
         [0030]     The riser leg support surfaces  26  are advantageously spaced downwardly from the top  32  of the inner wall  24  (as shown in  FIG. 8 ) such that an inner leg  34  of a connecting member  36  of the riser  14  can rest on the riser leg support surfaces  26 . The connecting member  36  has an inverted generally U-shape in cross section, having the inner leg  34  and an outer leg  38 , separated by an intermediate portion  40 . Risers having such a connecting member are described in U.S. Pat. Nos. 5,617,679 and 5,852,901, owned by the assignee of the present disclosure.  
         [0031]     As an alternative to the inner rib members  28 , the riser leg support surfaces  26  may instead be part of a series of horizontal ledges (not shown) provided on the interior of the inner wall  24 , or may even be the exposed surface of a continuous horizontal edge (not shown), extending along the entire inner perimeter of the inner wall  24 . From a manufacturing standpoint, the inner rib members  28  are more advantageous than the continuous ledge alternative, inasmuch as there is no mold penalty (in the form of more complex, and costly, injection mold designs) due to incorporation of the inner rib members  28 .  
         [0032]     By spacing the riser leg support surfaces  26  some distance down from the top  32  of the inner wall  24 , the inner leg  34  of a complementary-sized stackable riser component  14  having a connection member  36  rests on the riser leg support surfaces  26 . The outer leg  38  rests on one of the horizontal ribs  33  extending outwardly from the inner wall  24 . The intermediate portion  40  of the connection member  36  may be spaced a short distance from the top  32  of the inner wall  24  of the adapter ring  10  when there is no load imparted to the top of the stackable riser component  14 , but when loads are imparted thereto, the intermediate portion  40  may come into contact with the top  32  of the inner wall  24 . A gasket, or alternatively, butyl mastic, may be interposed between the intermediate portion  40  and the top  32  of the inner wall  24 .  
         [0033]     The inner wall  24  is reinforced by an angled reinforcement strut  42  (best shown in  FIG. 8 ), which preferably extends substantially the entire outer perimeter of the inner wall  24 . In the case of the circular-shaped adapter ring  10  as shown in the drawing figures, the angled reinforcement strut  42  extends about substantially the entire circumference of the inner wall  24 , but terminates at 180° intervals. The angled reinforcement strut  42  extends between the inner wall  24  and a top surface  44  of the bottom  18 . Known gas assist molding techniques may be employed to form the angled reinforcement strut  42 , such that a channel  46  exists between the inner wall  24 , the top  44  of the bottom  18 , and the angled reinforcement strut  42 . The termination points of the angled reinforcement strut  42  at 180° intervals are a result of those gas assist molding techniques.  
         [0034]     The adapter ring  10  is also provided with an outer wall  48 . The outer wall  48  is at the outside perimeter of the bottom  18 . The outer wall  48  is not intended to support any riser components or other structure directly thereon. The outer wall  48  thus serves as a buffering perimeter standing between backfill and the inner wall  24 . As such, transverse loads imposed by surrounding backfill (not shown) are absorbed, or at least dampened, by the outer wall  48 , providing the inner wall  24  with some measure of protection from the transverse loads. Without protection from transverse loads imposed by surrounding backfill, or sufficient reinforcement, the inner wall  24  would tend to buckle to some extent as a result of the loads, compromising the integrity of the connection between the adapter ring  10  and the next-higher component in a column, such as a riser  14 .  
         [0035]     As further reinforcement to the inner wall  24  and the angled reinforcement strut  42 , additional strut members  45  are provided between the inner wall  24 , the angled reinforcement strut  42 , the top of the bottom  32 , and the outer wall  48 . The additional strut members  45  may be formed of a single wall, or more preferably, a tent-like, or inverted V-shaped base  50  formed of first and second wall portions  52 ,  54 , and an upper wall portion  56 . Two or more screw bosses  55  (see  FIGS. 4 and 5 ) are provided in certain of the additional strut members  45 . By providing the screw bosses  55  on the exterior of the inner wall  24 , securement screws  57  used to secure the lower-most riser component  14  to the adapter ring  10  are isolated from the corrosive gases which may be present within the inner wall  24  and column of riser components  12  stacked thereon.  
         [0036]     Advantageously, as shown in  FIGS. 9-10 , the upper wall portion  56  of at least some of the additional strut members  45  may be provided with an extension, or stacking fin  58 , to facilitate stacking multiple adapter rings  10  together for storage, crating, and shipping purposes.  
         [0037]     Even more preferably, as shown in  FIGS. 10A and 10B , stacking fins  58  are provided with pins  41  that project vertically upwardly from the top of the stacking fins  58 . When the adapter rings  10  are stacked as shown in  FIG. 10B , the pins  41  are received in complementary pin-receiving recesses  21  provided in the bottom  18  of the next-higher adapter ring  10  in the stack. These interlocking pins  41  and pin-receiving recesses  21  advantageously inhibit relative movement of adjacent stacked adapter rings  10 .  
         [0038]     An important function of the angled reinforcement strut  42  and the additional strut members  45  is to provide strength, rigidity, and support to the adapter ring  10  as a whole, and to the bottom  18  and inner wall  24  in particular, when the adapter ring  10  is placed over a large diameter or polygonal opening in such a way that some of the inside wall  24  and bottom  18  is positioned directly over the opening, without any concrete lid  12  underneath, i.e. in a cantilevered fashion.  
         [0039]     The top surface  44  of the bottom  18  is preferably provided with raised circular bosses  60 , each having an angled interior surface  62 . Each of the raised circular bosses  60  defines a location for a user to drill a hole through the adapter ring  10  and underlying adhesive  22 , and into the concrete lid  12 . Nails, screws, or other rod fastener members (not shown) may then be used to stabilize the adapter  10 , and any stackable risers  14  that may be provided thereon, against lateral movement.  
         [0040]     The adapter ring  10  may also receive a riser pan  64  (as shown in  FIG. 11 ), such as the riser pan components disclosed in U.S. patent application Ser. No. 10/352,086, published as US 2003/0145527 A1, also owned by the assignee of the present disclosure. The use of a riser pan  64  in association with an adapter ring  10  advantageously allows a secondary cover, such as a concrete cover  66 , to be placed in a stack of stackable riser components  14  at an elevation higher than the concrete lid  12  of the tank on which the adapter ring  10  may be secured.  
         [0041]     As illustrated in  FIG. 11 , the adapter ring  10  could be used in combination with stackable riser components  14  and a riser pan  64  such that the adapter ring  10  is secured to the top of a concrete lid  12 , a riser pan  64  is then received on the adapter ring  10 , and as many stackable riser components  14  as are needed to reach a desired elevation, such as grade level, are then received in a column on the riser pan  64 . A riser cover  68  may be received on the uppermost stackable riser component  14 , and a secondary cover, such as a concrete cover  66 , may be received in the frustro-conical portion  70  of the riser pan  64 .  
         [0042]     Another advantageous arrangement of components facilitated by the adapter ring  10  is shown in  FIG. 12 , in which a riser cover  68  is shown oriented directly over an adapter ring  10  secured to a lid  12  in the above-described manner, without any intermediate stackable riser components. Preferably, the riser cover  68  is provided with its own molded-in gasket, such that the riser cover  68  may be secured directly to the adapter ring  10  without the need for additional sealant, such as butyl mastic, and still achieve a substantially liquid tight closure. Such an adapter ring  10  and riser cover  68 -only combination might be used in end-use applications where there is only shallow backfill, i.e. of less than one riser&#39;s height, over the septic tank (e.g., less than 6″), or where there is no need for full time access at grade level, via a column of stackable risers, over a particular tank opening, since there are one or more other tank openings with ground access riser columns over them for a given tank.  
         [0043]     Yet another advantageous arrangement of components facilitated by the adapter ring  10  is shown in  FIG. 13 . In that partially exploded view, an adapter ring  10  is shown secured directly to an upper concrete riser  72 . The upper concrete riser  72  can be stacked over another concrete riser  72 . The adapter ring  10  advantageously enables a riser cover  68  to be utilized to cap-off a column or stack of concrete risers  72 . It will be understood by those in the art that the various arrangements shown are exemplary, and that any of the various components shown stacked on adapter rings  10  of other drawing figures could likewise be stacked onto the adapter ring  10  as shown in  FIG. 13 . Thus, as an alternative to stacking a riser cover  68  on the adapter ring  10  in  FIG. 13 , one could stack a riser pan  64  of a stackable riser component  14 , thereby increasing the versatility of a stack of conventional concrete risers.  
         [0044]     It is typical for stackable riser systems to be vacuum-tested in order to predict their resistance to leakage. The following test procedures may be utilized to demonstrate the performance of an adapter ring  10  under vacuum testing: First, place an adapter ring  10  down on a concrete slab with an adhesive material  22  consisting of butyl mastic rope therebetween. Next, place a column of stackable riser components  14  on the adapter ring  10 , using additional adhesive material  22  in the form of butyl mastic rope between adjacent risers  14 , and between the lowermost riser  14  and the adapter ring  10 . Provide a plastic riser cover  68  on top of the column of risers  14 , with a foamed-in polyurethane gasket (not shown) provided within a channel of the plastic riser cover  68 . Next, secure the plastic riser cover  68  to the uppermost riser  14  using screws. Then, for test purposes, using a vacuum pump and vacuum gauge, draw a 10″ vacuum in that now erected system of adapter plate, riser stack, and cover. In testing according to these procedures, it has been found that the assembled system (including an adapter ring  10 , column of risers  14 , and riser cover  68 ) withstands 10″ vacuum for at least 30 minutes.  
         [0045]     While various embodiments of adapter rings and combinations of adapter rings with various components have been disclosed herein, it is understood that variations may be made thereto without departing from the scope of the appended claims.