Abstract:
An access device for installation to a condensation drainage system, such as a drain line of an HVAC unit, includes a main body with at least one connecting port for sealed, fluid receiving connection to the drainage system and an open top communicating with an interior cavity. A top cover releasably secures to the main body to completely cover the open top. An overflow safety switch is removably held in operable position within the interior cavity and below the top cover. The switch senses the level of condensate liquid accumulating with the interior cavity and sends an electronic signal to disable the condensation producing equipment if the liquid reaches a predetermined level.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This patent application is a Continuation-In-Part of patent application Ser. No. 14/451,589 filed on Aug. 5, 2014, which is a Continuation-In-Part of patent application Ser. No. 13/953,948 filed on Jul. 30, 2013, which is based on provisional patent application Ser. No. 61/716,238 filed on Oct. 19, 2012. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to an access device for inline installation to drain lines and other fluid transfer conduits and, more particularly, to an inline access device that allows for cleaning and removing clogs in air conditioning and refrigeration condensate drain lines and other fluid transfer lines, and wherein the access device is equipped with an internal overflow safety switch. 
       DISCUSSION OF THE RELATED ART 
       [0003]    In various systems and equipment, there is a need to transfer and/or drain liquid from the equipment to a separate location. For example, in air conditioning and refrigeration systems, condensation naturally occurs as warm, humid air passes over the exterior of the evaporator coil in the HVACR unit. Typically, the condensation drips from the evaporator coil into a condensate collection pan positioned below the evaporator coil. From the collection pan, the liquid condensate is directed through a drain line that leads to an appropriate discharge location, such as the exterior of a building. It is not uncommon for these and other types of drain lines to occasionally become partially or completely clogged, resulting in a backup of condensate liquid in the drain line and the collection pan of the HVACR unit. In particular, the slow and continuous movement of condensate liquid through the drain line (i.e., by gravity transfer) encourages the growth and accumulation of algae, bacteria, dust, corrosive residue and other debris that builds up in the drain line and eventually causes a partial or complete blockage. The backup of condensate in the drain line and collection pan can result in an accidental overflow of condensate during the continuous operation of the HVACR equipment, possibly resulting in extensive and costly damage to the building structure and contents. This is a common problem that is well known in the industry. 
         [0004]    In order to avoid clogs and accidental condensate overflows in HVACR condensate drain lines, it is recommended that the drain lines be cleaned (i.e., cleared of debris and residue) at least twice a year during normal maintenance procedures. Typically, cleaning of drain lines is achieved by introducing a pressurized flow of liquid or gas through one end of the drain line which serves to push debris, residue and blockages through the drain line and out through the opposite end. In most instances, when using a pressurized flow through the drain line for cleaning, it is desirous to gain access to the upper end of the condensate drain line near the air conditioner or refrigeration unit so that the pressure may be applied at the upper end, while pushing the clogging materials out through the opposite end, usually at an exterior of the building. Access to the upper end of the drain line requires detaching the drain line from the air conditioning or refrigeration unit and then replacing the drain line wherein the maintenance is completed. In many instances, access to the drain line can only be achieved by cutting the drain line near the HVACR unit to create an open end for injection of a pressurized gas or fluid. After cleaning, the cut drain line must then be repaired by inserting a connecting joint. This repair process compromises the water tight integrity of the drain line, and can often result in leaks at the repair joint. 
         [0005]    In order to overcome the above-described problems associated with drain line clogs and maintenance for cleaning drain lines in HVACR systems, others have proposed for the installation of permanent inline assemblies that allow for access to the drain line to inject pressurized gas or liquid without the need of separating the drain line from the equipment or cutting the drain line. These various inline assemblies typically employ the use of a manually operated ball valve or gate valve that is closed during the clean out procedure so that the forced flow of gas or liquid is directed in one direction, usually away from the HVACR equipment. Use of a valve is advantageous in order to close off the drain line between the valve and a clog in the line. The pressurized flow of gas or liquid can then be introduced into the drain line between the closed valve and the clog, creating sufficient pressure to push the clog out through the line until the drain line is completely cleared of debris and clogging residue. However, after the cleanout procedure, the manually operated valve must be opened by the service person, otherwise the closed valve will act as a clog by preventing flow and draining of condensate liquid through the drain line to the desired discharge location. 
         [0006]    The need to operate a manual shut-off valve in the various inline drain flushing systems of the related art presents several problems. In particular, the rotational force exerted on the manual valve control can cause bending or breaking of the drain line pipe and/or connecting joints, especially over time when the valve accumulates residue and tends to stick and resist movement. Eventually, the valve would need to be replaced which requires cutting the drain line at two locations. Another major concern with use of manually operated shut-off valves along an HVACR drain line is human error. If the service person forgets to re-open the valve after cleaning the drain line, the liquid condensate will not be permitted to drain out from the drain line and will, instead, back up into the HVACR unit drain pan, possibly resulting in an accidental overflow as the HVACR unit continues to operate. 
         [0007]    Considering the foregoing problems and limitations associated with existing drain line clearance methods and devices, there exists a need for a drain line access device that is structured for inline installation to an existing drain line without obstructing the flow of drain line contents, and which permits convenient flushing of the drain line in both upstream and downstream directions. There is a further need for a drain line access device that includes an overflow safety switch within the housing of the device for disabling operation of an HVAC unit or other equipment connected to the drain line in the event of a clog/obstruction in the drain line that results in a back-up of liquid flow into the access device. 
       OBJECTS AND ADVANTAGES OF THE INVENTION 
       [0008]    Considering the forgoing, it is a primary object of the present invention to provide inline access to fluid transfer lines, such as drain lines in HVACR systems, for purposes of cleaning (e.g., flushing) the lines without disrupting the integrity of the lines and without the need to manually operate shut-off valves to perform the cleaning 
         [0009]    It is a further object of the present invention to provide a drain line access device that allows for easy connection of a compressed gas or liquid delivery source to clean the line and clear any clogs. 
         [0010]    It is still a further object of the present invention to provide a drain line access device for cleaning fluid transfer lines and clearing clogs either upstream or downstream of the device. 
         [0011]    It is yet a further object of the present invention to provide a drain line access device that has an easily removable cover for providing convenient access and insertion of adapters for flushing the drain line in either direction without cutting, damaging or disrupting the fluid transfer line (e.g., drain line). 
         [0012]    It is still a further object of the present invention to provide a drain line access device that is equipped with an internal overflow safety switch to disable an HVAC unit or other equipment connected to the drain line in the event of a clog/obstruction in the drain line. 
         [0013]    It is still a further object of the present invention to provide a drain line access device that is equipped with an internal overflow safety switch that can be easily removed to allow unobstructed access to the drain line for flushing and clearing a clog in either the upstream or downstream direction, and wherein the overflow safety switch is easy replaced and sealed within the housing of the access device for normal operation. 
         [0014]    These and other advantages of some embodiments are more readily apparent with reference to the detailed description and accompanying drawings. 
       SUMMARY OF THE INVENTION 
       [0015]    The present invention is directed to an access device for inline installation to a drain line in a fluid transfer system. In one preferred embodiment, the access device is connected to a drain line extending from an air handler unit of an HVAC system to allow easy and convenient access to the drain line in order to clear a clog/obstruction in the drain line or to add clog preventing agents on a periodic basis. The access device includes a main body having connection ports on opposite ends for inline installation to the drain line (between the condensation producing source and drain discharge). The device includes a removable top cover and an adapter that is sized and configured for insertion into the interior cavity of the main body and fitted receipt within the inside of one of the input or outlet ports (upstream or downstream direction). The adapter allows for connection of virtually any pressurized gas or liquid flow source, or a vacuum source, as well as pouring of a liquid (e.g. anti-clogging agent) either upstream or downstream in the drain line for flushing out and/or preventing a clog in the drain line. A further embodiment of the device includes a main body having one connection port for connection with the auxiliary outlet of a drain pan. 
         [0016]    The access device of the present invention further includes an overflow safety switch and/or liquid level sensor and alarm (e.g. float switch) that is removably supported within an interior chamber of the main body of the access device for detecting a clog/obstruction in the drain line. In a preferred embodiment, the overflow safety switch is electrically wired to the HVAC unit for disabling operation of the HVAC unit in the event of a clog/obstruction in the drain line that results in liquid flow backing up into the access device. 
         [0017]    In a preferred embodiment, the overflow safety switch is a float switch and is supported within the interior chamber of the access device by a removable bracket that has a C-clip for attachment to the tubular body of the float switch. The tubular body has an arrangement of vertically spaced grooves (preferably three grooves) that allow for selective adjustment of the height of the float switch within the interior chamber of the access device. The electrical wires of the float switch extend out through a cut-out opening in the side wall of the main body of the access device for connection to the HVAC equipment. A closure piece is epoxied or glued to the wires so that the closure piece remains attached and sealed to the wires. The closure piece is congruently shaped and configured to fit within the cut-out opening in the side wall of the main body and includes a gasket or ring seal that fits within a groove surrounding the cut-out opening in order to create a water-tight seal with the side wall and the top cover. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    For a fuller understanding of the nature of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings in which: 
           [0019]      FIG. 1  is a top perspective view of the drain line access device of the present invention shown with the top cover closed and sealed to the main body and having a pair of electrical wires from an internal overflow safety switch extending out through a sealed side port; 
           [0020]      FIG. 2  is a top perspective view of the drain line access device of  FIG. 1  shown with the top cover removed to reveal the overflow safety switch supported within an interior chamber of the main body by a removable bracket; 
           [0021]      FIG. 3  is a isolated perspective view of the removable bracket; 
           [0022]      FIG. 4  is a top plan view showing the drain line access device with the top cover removed and with the removable bracket supported within a slot within the interior cavity of the main body to thereby position a C-clip on the bracket generally centered within the interior cavity for removable attachment of the overflow safety switch thereto; 
           [0023]      FIG. 5  is a side elevational view showing the overflow safety switch attached to the C-clip of the bracket; 
           [0024]      FIG. 6A  is side elevational view, shown in partial cross-section, showing the main body of the access device with the top cover removed and an adaptor installed in the downstream direction of the drain line; 
           [0025]      FIG. 6B  is a side elevational view, shown in partial cross-section, showing the main body of the device with the top cover removed and the adaptor installed in the upstream direction of the drain line; 
           [0026]      FIG. 7  is a top perspective view of the access device shown with the top cover removed and a closure piece sealed to the wires of the overflow safety switch and readily positioned for sealed receipt within a cut-out opening on the side wall of the main body; and 
           [0027]      FIG. 8  is a side elevational view of the access device, with the top cover attached and sealed to the main body and the closure piece, thereby allowing the wires for the overflow safety switch to extend out through the side of the main body while maintaining a water tight seal. 
           [0028]      FIG. 9  is a side elevational view, shown in partial cross-section, illustrating an alternative embodiment of the drain line access device having one connector port for inline installation on a drain line or directly to a drain pan auxiliary outlet of an HVAC unit; and 
           [0029]      FIG. 10  is a side elevational view of the drain line access device of  FIG. 1 , shown partially exploded, with a cap for sealing one connector port opening and a coupling for attaching the opposite connector port of the device to the auxiliary outlet of a drain pan. 
       
    
    
       [0030]    Like reference numerals refer to like parts throughout the several views of the drawings. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0031]    Referring to the several views of the drawings, the drain line access device of the present invention is shown and is generally indicated as  10 . 
         [0032]    As seen in  FIGS. 1 and 2 , the access device  10  includes a main body  12  surrounding an interior chamber  14 . The main body  12  has an input connector port  16 A and an outlet connector port  16 B. The input and outlet connector ports  16 A and  16 B are positioned on opposite ends of the main body and are each sized and configured for engaged receipt of opposing ends of a drain line extension, thereby allowing for inline installation of the access device  10  to the drain line. The top of the main body is open and is surrounded by a rim  15 . In a preferred embodiment, the top rim  15  is structured for sealed engagement with a gasket  17  that is fitted within a groove in the underside of a top cover  22  that normally covers and closes the open top of the main body. In a preferred embodiment, the top cover  22  is hingedly secured to one end of the main body  12  by a double pin separating hinge assembly  24 , including removable male hinge members  25 A and female hinge members  25 B. The top cover  22  is releasably secured to the main body  12  by a latch mechanism  26  on the end opposite to the hinge assembly  24 . When secured to the main body  12 , the top cover  22  covers and seals the open top of the main body  12  to define an inner channel  28  between input and outlet connector ports  16 A and  16 B. 
         [0033]    In one embodiment, input port  16 A attaches to a drain line extending from a condensation producing source (e.g., an air handler unit of an HVAC system) and outlet port  16 B is sized and configured for engaged receipt of a drain line extension leading to a drain discharge. 
         [0034]    The top cover  22  is easily opened and/or removable from the main body  12  at the double pin separating hinge assembly  24  by separating the male hinge members  25 A from the female hinge members  25 B. The latch  26  on the opposite end of the main body hinges upwardly into engagement with fastening member  40  on the top cover  22  for sealing the top cover  22  to the top rim of the main body and covering relation to the open top. To open or remove the top cover, the latch  26  is hingedly rotated away from the top cover  22  so that the latch separates from the fastening member  40 . The top cover  22  can then be opened (and completely removed if desired) to gain access to the interior chamber of the main body as seen in  FIGS. 2 ,  4  and  7 . 
         [0035]    Referring to  FIGS. 2-4 , an overflow safety switch  30  is removably supported within the interior chamber of the main body by a removable bracket  50 . The bracket  50  has a mounting member  52  that is removably received within a transverse slot  54  formed within the interior chamber of the main body. When the mounting member  52  is received within transverse slot  54 , the bracket  50  is secured for holding the overflow safety switch  30  in operable position within the interior chamber  14  of the access device  10 . More particularly, the bracket  50  includes an arm  56  extending outwardly from the mounting member. A C-clip  58  is provided on an end of the arm  56  and is normally positioned near the center of the interior chamber, as seen in  FIG. 4 . The C-clip  58  is sized, structured and configured for removable, engaged receipt with the overflow safety switch  30 . In a preferred embodiment, the overflow safety switch  30  is a float switch having a vertically extending hollow tubular body  32  and a buoyant annular float member  34  moveable along an outer surface of the tubular body  32  between a lower stop member  36  and an upper stop member  38 . The float switch  30  may have a magnetically driven read switch within the tubular body, and wherein the annular float member  34  is provided with a magnet, whereby the magnetically driven read switch is responsive to movement of the float member  34  to close the switch and complete and electrical circuit upon the float member  34  rising to a predetermined position on the hollow tubular body  32 . Other types of overflow safety switches are fully contemplated within the spirit and scope of the invention including, but not limited to, a contact switch with probes that are positioned to contact the liquid when reaching a predetermined level to thereby close the switch and send a shutoff signal to the HVAC unit or other condensation producing equipment or machinery. 
         [0036]    As seen in  FIG. 5 , the C-clip  58  of the bracket  50  is removably secured to the tubular body  32  of the overflow safety switch  30  to support the overflow safety switch in a generally vertical and upright position. In a preferred embodiment, the tubular body  32  of the float switch is provided with three annular grooves  33   a,    33   b  and  33   c  in vertically spaced relation from one another. Each of the three annular grooves is structured and configured for removable attachment of the C-clip  58 , thereby allowing for selective attachment of the C-clip  58  of the bracket to any one of the three annular grooves for the purpose of adjusting the height of the float switch relative to a bottom (i.e., floor) of the interior chamber. For example, the bottom annular groove  33   c  may allow adjusted position of the float switch  30  so that the bottom end of the float switch is positioned one quarter inch above the bottom of the interior chamber  14 . The second or middle annular groove  33   b  would allow adjustable positioning of the float switch  30  so that the bottom end of the float switch  30  is positioned one eighth of an inch above the bottom of the interior chamber  14 . Finally, the top annular groove  33   a  would allow adjusted positioning of the flow switch  30  so that the bottom end of the flow switch  30  sits on the bottom of the interior chamber  14  of the access device  10 . 
         [0037]    As seen in  FIGS. 2-4 , the bracket  50  is provided with a handle  59  that allows the bracket to be easily pulled up and removed from the transverse slot within the interior chamber of the main body, thereby allowing for removal of both the bracket  50  and the float switch  30 . Removal of the bracket  50  and float switch  30  allows for unobstructed access to the interior chamber  14  and the input and outlet connector ports  16 A and  16 B. 
         [0038]    Referring to  FIGS. 6A and 6B , a generally L-shaped (i.e., 90 degree angle) adaptor  60  is shown installed in the downstream and upstream directions, respectively, wherein the adaptor  60  engages one of the input and outlet connector ports  16 A and  16 B. In a preferred embodiment, the adaptor  60  is formed as a rigid tubular one-piece structure. A flow of pressurized gas is directed from a compressed gas source through the adaptor  60  and then enters one of the connector ports  16 A and  16 B, which is in connection with the drain line for flushing out a clog. Alternatively, a pressurized liquid flow (e.g., water) may be directed through the adapter  60  for flushing out the clog. When a vacuum force is used for clearing a clog, a vacuum may be attached to the adaptor. For each of the above applications (i.e., compressed gas, pressurized liquid flow, and vacuum), a coupling may be used between the connector hose and the adaptor  60  in order to ensure a water tight and/or air tight seal. 
         [0039]    Referring to  FIGS. 7 and 8 , the electrical wires  70  of the float switch  30  are conveniently directed out through the side of the main body of the access device  10 . This allows the top cover  22  to be easily opened and/or removed and replaced without disturbing the position of the float switch  30 . Thus, the top cover  22  can be opened and/or removed and the correct positioning and operation of the float switch  30  within the interior chamber  14  can be easily observed and adjusted prior to replacing the top cover. This also allows for the opening and/or removal of the top cover  22  for purposes of adding anti-clogging agents to the drain line without disturbing the position of the float switch  30 . As seen in  FIGS. 7 and 8 , the wires  70  extend out through a cut-out opening  80  in the side wall  13  of the main body  12 . A closure piece  82  is epoxied, glued or otherwise sealed to the wires  70  so that the closure piece  82  remains attached to the wires  70  with a water tight seal created between the wires  70  and the closure piece  82 . The closure piece  82  is congruently shaped and configured to fit within the cut-out opening  80  in the side wall  13  of the main body  12  and includes a gasket or ring seal that fits within a groove surrounding the cut-out opening  80  where the two create a water tight seal between the closure piece  82 , the side wall  13  and the top cover  22 . Alternatively, a grommet or other sealing means can be used to allow for sealed passage of the wires  70  through the side wall  13  of the main body. 
         [0040]    Referring to  FIG. 9 , an alternative embodiment of the device  10  is shown, wherein the main body  12  includes only one connector port  16 A. Alternatively, a cap may be used to seal one of the two openings ( 16 A or  16 B) on the embodiment of the main body  12  having two connector ports  16 A and  16 B, as shown in  FIGS. 1 ,  6 A and  6 B. This alternative embodiment of the device  10  is structured for securing to the auxiliary outlet of a drain pan. The connector port  16 A may be molded with threads for screwing directly into the auxiliary outlet or, alternatively, a coupling  94  (see  FIG. 10 ) having a lengthwise channel extending therethrough may be used for achieving a water tight and air tight connected sealed between the connector port  16 A and the auxiliary outlet  100  of the drain pan. 
         [0041]    Referring to  FIG. 10 , a main body  12  having connector ports  16 A and  16 B can be converted into the embodiment of the device  10  shown in  FIG. 9 , as described above. Specifically, a cap  90  includes an annular wall  92  that is sized and configured for engaged, congruent receipt within the connector port  16 B for producing an air tight and liquid tight seal between the cap  90  and the interior cavity  14  of the main body  12 . The coupling  94  having a lengthwise channel extending therethrough includes an annular wall  96  at one end that is sized and configured for engaged, congruent receipt within the connector port  16 A for achieving an air tight and liquid tight sealed connection. The opposite end of the coupling  94  includes a threaded exterior surface  98  that is sized for threaded, engaged attachment with the auxiliary outlet of a drain pan. 
         [0042]    While the present invention has been shown and described in accordance with several preferred and practical embodiments, it is recognized that departures from the instant disclosure are contemplated within the spirit and scope of the present invention which are not to be limited except as defined in the following claims, as interpreted under the Doctrine of Equivalents.