Abstract:
An air conditioner filter removing system for air filters located in elevated return-air vents, such as return-air vent mounted in a ceiling or upper wall. The device consists of a filter-grabbing mechanism that can be mounted to an extension pole. The filter-grabbing mechanism has teeth protruding from it to grab an air filter and a holding plate where the filter is balanced once engaged by the teeth. In its preferred embodiment, the system has a holding means present on the return-air vent so the filter-grabbing mechanism can easily pull the vent open. Further, the preferred embodiment also has kicker plates kick the teeth out of the grill louvers they are inserted into, on the vent door.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    Not applicable. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention relates generally to a filter changing system for HVAC systems that have return-air vents mounted in elevated places such as ceilings or upper walls. More specifically, the invention relates to a filter-grabbing device that can be mounted to an extension pole. The filter-grabbing device is configured to open the vent door on an elevated return-air vent, take the dirty air filter from the vent, replace the dirty air filter with a clean air filter, and close the vent door. 
         [0005]    2. Description of the Related Art 
         [0006]    Within the field of HVAC repair and maintenance, there are numerous tools for repairing, calibrating, and generally maintaining HVAC systems. These tools are geared toward ensuring that the HVAC system is performing at its optimal level. Despite the crowded field, no known tool exists for changing air filters when the air filter is located in an elevated return-air vent. 
         [0007]    During normal operation of an HVAC system, air is continually re-circulated through the system. As part of the re-circulation process, a blower inside the HVAC system pulls external air through a return-air vent. External air is the air located within the structure being heated, cooled, and/or ventilated by the HVAC system but not within the HVAC system itself. As the blower pulls external air through the return-air vent, the external air passes through an air filter and enters into the HVAC system. The number of return-air vents and corresponding air filters in an HVAC system varies, depending on the design of the particular system. 
         [0008]    Air filters help prevent harmful dust and other particles from entering into the HVAC system. The filter media accumulates the dust and other particles as the external air passes through it. Once the filter media becomes saturated, the blower must work harder to pull the external air into the system, thereby increasing the strain on the blower. Increased strain on the blower may cause the blower to overheat and may cripple the HVAC system altogether. Thus, proper maintenance of an HVAC system requires air filters to be changed regularly. 
         [0009]    To change the air filter, the return-air vent typically contains a vent door that is affixed to the vent perimeter of the return-air vent with hinges. When closed, one or more levers lock the vent door in place within the vent perimeter of the return-air vent. To open the vent door, an HVAC technician slides levers on the return-air vent into the unlocked position and pulls the vent door open. With the vent door now open, the technician removes the dirty air filter and replaces it with a clean one. 
         [0010]    When return-air vents are located in elevated positions such as ceilings or upper walls, the technician cannot reach them without using a ladder. From a safety standpoint, each time a technician climbs a ladder to change an air filter there is a risk that the technician will fall from the ladder and sustain an injury. Further, if an elevated return-air vent is located over a piece of furniture or another item that is difficult to move, placing a ladder directly under the return-air vent may not be possible. Instead, the technician must position the ladder as close to the return-air vent as possible and reach for the vent. Of course, reaching for the vent while standing on a ladder only further increases the risk posed by elevated return-air vents. It is these elevated return-air vents to which the present invention is directed. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The present invention is a filter-changing system that allows HVAC technicians or others to change air filters in elevated return-air vents without using a ladder. The filter changing-system consists of a filter-grabbing device with a mounting means that allows the filter-grabbing device to be mounted to an extension pole. Although a variety of mounting means are possible, in its preferred embodiment the mounting means allows for pivotal movement of the filter-grabbing device, with pivotal movement possible at a single axis of rotation or at two axes of rotation. 
         [0012]    Preferably, the filter-changing system includes an improved holding means for holding the vent door in its closed position. The improved holding means is a separate piece from the filter-grabbing device and allows the vent door to be pulled open with the filter-grabbing device. In its preferred embodiment, the holding means is a plurality of magnets mounted to the vent perimeter of the return-air vent or a plurality of magnets mounted to the vent door. 
         [0013]    In practice, the vent door should be opened with the filter-grabbing device while the blower is operating so the air filter remains in place from the suction of the blower. Using the filter-grabbing device, the air filter is grabbed, pulled from the vent perimeter of the return-air vent, and brought down from its elevated position. A new filter is then inserted on the filter-grabbing device, lifted into the elevated position, and placed within the vent perimeter of the return-air vent. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  illustrates a perspective view of incorporating the preferred embodiment of the filter-changing system of the present invention. 
           [0015]      FIG. 2  shows a top view of the preferred embodiment for the filter-grabbing device. 
           [0016]      FIG. 3  shows a side view of the preferred embodiment for the filter-grabbing device and the preferred embodiment of the mounting means. 
           [0017]      FIG. 4  shows a bottom perspective view of the preferred embodiment for the filter-grabbing device the preferred embodiment of the mounting means. 
           [0018]      FIG. 5  shows an exploded, bottom perspective view of the preferred embodiment for the filter-grabbing device and the preferred embodiment of the mounting means. 
           [0019]      FIG. 6  shows an exploded, bottom perspective view of an alternative embodiment of the mounting means for the present invention. 
           [0020]      FIG. 7  shows a side view of the preferred location of the preferred holding means when said holding means is mounted to the vent perimeter of the return-air vent. 
           [0021]      FIG. 8  shows a side view of the preferred location of the preferred holding means when said holding means is mounted to the vent door. 
           [0022]      FIG. 9  shows a side view of an alternate location for the preferred holding means when said holding means is mounted to the vent perimeter of the return-air vent. 
           [0023]      FIG. 10  shows a side view of an alternate location for the preferred holding means when said holding means is mounted to the vent door. 
           [0024]      FIG. 11  is a bottom perspective view showing the filter-grabbing device engaged with the vent door prior to opening. 
           [0025]      FIG. 12  is a bottom perspective view showing the filter-grabbing device engaged with an air filter after the vent door has been opened. 
           [0026]      FIG. 13  is a perspective view showing the filter-grabbing device engaged with support structures on an air filter. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]      FIG. 1  is a bottom perspective view for the preferred embodiment of the present invention.  FIG. 1  shows a filter-changing system  20  and a return-air vent  22  that is positioned in a ceiling. The return-air vent  22  has a vent perimeter  24  and a vent door  26  that contains grill louvers  28 . The vent door  26  is attached to the vent perimeter  24  of the return-air vent  22  with hinges  30 . 
         [0028]    The filter-changing system  20  has a filter-grabbing device  32  and a mounting means  34  attached to the filter-grabbing device  32 , which allows the filter-grabbing device  32  to be permanently or temporarily mounted to an extension pole  36 . Preferably, the filter-changing system  20  includes a holding means  38  that creates a force to hold the vent door  26  closed at the vent perimeter  24  yet allows the vent door  26  to be pulled open with the filter-grabbing device  32 . 
         [0029]      FIG. 2  shows a top view of the filter-grabbing device  32  in its preferred embodiment. The filter-grabbing device  32  has a holding plate  40  with a substantially flat top surface  42  and a bottom surface  44  (see  FIG. 3 ). The holding plate  40  has a plurality of sides  46  and and preferably shaped as a rectangle; however, the holding plate  40  can be variety of shapes. 
         [0030]    Protruding from at least one of the plurality of sides  46  is a plurality of teeth  48  that are sized to fit between the grill louvers  28  on the vent door  26 . Although a plurality of teeth  48  preferably protrude from holding plate  40 , a single tooth sized to fit between the grill louvers  28  on the vent door  26  could protrude from the holding plate  40  and accomplish the object of the present invention. As shown in  FIG. 3 , the plurality of teeth  48  are aligned substantially planar to the top surface  42  of the holding plate  40 . Although slight angling of the plurality of teeth  48  may be acceptable, the manner in which the the filter-grabbing device  32  engages an air filter and the manner in which the air filter rests on the holding plate  40  dictates that the plurality of teeth  48  are substantially planar to the top surface  42 . 
         [0031]    In the preferred embodiment, the holding plate  40  has two teeth (i.e., a set) from the plurality of teeth  48  protruding from each of three sides from the plurality of sides  46 . Instead of having teeth, the fourth side from the plurality of sides  46  has a curved end  50 , which is large enough to prevent the fourth side from entering into the grill louvers  28  on the vent door  26 . On each of the three sides that have a set of teeth, the two teeth are spaced a predetermined distance apart from one another, and, the predetermined distance between each set of teeth is different for each side. 
         [0032]    In the preferred embodiment, the holding plate  40  also has a plurality of kicker plates  52  protruding from it, though a single kicker plate or even no kicker plate may be present in alternate embodiments. As shown in  FIG. 3 , the kicker plates  52  protrude from the holding plate  40  at a downward angle relative to the bottom surface  44  of the holding plate  40 . Preferably, a single kicker plate protrudes from the holding plate  40  at each of the three sides where a set of teeth is present and protrudes from the predetermined distance between the teeth in each set of teeth. 
         [0033]    Also present in the preferred embodiment is a plurality of notches  54  cut into the sides  46  of the holding plate  40 , though a single notch or no notches may be present. The plurality of notches  54  are sized to accept at least a portion of an air register damper (not shown), so the filter-grabbing device  32  can readily move the air register damper. As such, the filter-grabbing device  32  can readily open and close air registers, thereby controlling the flow of air from the HVAC system into the structure that is being heated, cooled, and/or ventilated by the HVAC system from the floor. 
         [0034]      FIGS. 2 and 3  also show a frictionous material  56  that is preferably on the top surface  42  of the holding plate  40 . The frictionous material  54  is any material that increases the coefficient of friction for the top surface  42  yet substantially preserves the overall flatness of the top surface  42 . In this regard, the air filter must still be able to balance on the top surface  42  of the holding plate  40  when the frictionous material  56  is present. 
         [0035]      FIG. 4  shows a bottom perspective view of the preferred embodiments of the filter-grabbing device  32  and the mounting means  38 . The preferred mounting means  38  has a first clevis mount  58  attached to the bottom surface  44  of the holding plate  40 . Preferably, the first clevis mount  58  has a wide base  60 ; however, the base  60  may be much narrower and may not be present at all. In addition, the first clevis mount  58  and the holding plate  40  are preferably manufactured as a single piece, but, the first clevis mount  58  may be a separately manufactured piece that is permanently or removeably attached to the bottom surface  44  of the holding plate  40 . 
         [0036]    The first clevis mount  58  is connected to a first clevis  62 , which is located on a dual-pivot linkage  64 , with a first clevis pin  66  and a first clevis wing nut  68 . When connected, the first clevis mount  58  and the first clevis  62  form a first clevis joint with an axis of rotation. The dual-pivot linkage  64  also has a second clevis mount  70  that faces the opposite direction of the first clevis  62  and is transverse to the first clevis  62 . 
         [0037]    The second clevis mount  70  of the dual-pivot linkage  64  is connected to a second clevis  72  with a second clevis pin  74  and a second clevis wing nut  76 . When connected the second clevis mount  70  and the second clevis  72  form a second clevis joint with an axis of rotation transverse to the axis of rotation formed by the first clevis joint. Preferably, the second clevis mount  70  and the first clevis mount  58  are sized and shaped identically so that the second clevis  72  can be connected to the second clevis mount  70  or the first clevis mount  58 . When the second clevis  72  is connected to the first clevis mount  58 , the dual-pivot linkage  64  is not present and only a single axis of rotation is possible. 
         [0038]    The second clevis  72  is attachable to the extension pole  36  (see  FIG. 1 ) in that the second clevis  72  can be permanently or removeably joined to the extension pole  36 . In one embodiment, the second clevis  72  may even be integrated into the extension pole  36  so that it is a permanent part of the extension pole. However, in the preferred embodiment the second clevis  72  can be removeably joined to the extension pole  36  with the type of connection commonly found on telescoping poles for pool cleaning equipment, similar to the connection shown in U.S. Pat. No. 4,247,216. Nonetheless, the second clevis  72  may bejoined to the extension pole  36  in any manner, as long as the junction will withstand the forces exerted on the junction while the filter-changing system  20  is used. 
         [0039]    As noted, the mounting means  38  allows the filter-grabbing device  32  to be permanently or temporarily mounted to the extension pole  36 . With regard to permanent mounting, the filter-grabbing device  32  may be mounted to the extension pole  36  with a mounting means  38  such as a weld, a solder, a cement, or a glue. In contrast, the mounting means  38  may be a fastener or a plurality of fasteners such as rivets, screws, or bolts, thereby creating a semi-permanent mount between the extension pole  36  and the filter-grabbing device  32 . The mounting means  38  may be a temporary mounting system, such as a magnet, Velcro, snaps, or a male/female receptacle on the bottom surface  44  of the holding plate  40  that receives or enters into a corresponding receptacle on the extension pole  36  and is secured thereto. 
         [0040]    Further, the mounting means  38  could be other types of pivotable joints similar to the preferred mounting means  38  or a rotational type of joint. For example, in an alternative embodiment the preferred mounting means  38  is inverted such that the structures present in the preferred embodiment are inverted. In this regard, a first clevis and not a first clevis mount  58  would be on the bottom surface  44  of the holding plate  40  and would be connected to a first clevis mount on the dual-pivot linkage  64 . An example of a rotational joint that could be employed as the mounting means  38  is a ball-and-socket joint, sometimes known as a ball-and-socket swivel. 
         [0041]    An alternative embodiment of a pivotable mounting means  38 , known as a “Ratchet Mount,” is shown in  FIG. 6 . In the Ratchet Mount mounting means  38 , a first half of a ratchet mount  78  has a base  80  and can be attached to the bottom surface  44  of the holding plate  40 . Although the first half of a ratchet mount  78  is shown as a separately manufactured piece that attaches to the bottom surface  44  of the holding plate  40  with screws (not shown), the first half of a ratchet mount  78  may be attached in other ways. For example, it may be manufactured as a single piece with the holding plate  40 . 
         [0042]    The first half of a ratchet mount  78  is rounded on its distal end and has gripping grooves  82 . The first half of a ratchet mount  78  connects to a second half of a ratchet mount  84 , which is located on a dual-pivot ratchet linkage  86 , with a first ratchet fastener  88  and a first ratchet wing nut  90 . The second half of a ratchet mount  84  has gripping grooves  92  that engage the gripping grooves  82  on the first half of a ratchet mount  78  when the first ratchet wing nut  90  is tightened. When connected, the first half of a ratchet mount  78  and the second half of a ratchet mount  84  form a first ratchet joint with an axis of rotation. 
         [0043]    The dual-pivot ratchet linkage  86  also has a third half of a ratchet mount  94  that faces the opposite direction of the second half of a ratchet mount  84  and is transverse to the second half of a ratchet mount  84 . The third half of a ratchet mount  94  connects to a fourth half of a ratchet mount  96  with a second ratchet fastener  98  and a second ratchet wing nut  100 . When connected, the third half of a ratchet mount  94  and the fourth half of a ratchet mount  96  form a second ratchet joint with an axis of rotation that is transverse to the axis of rotation formed by the first ratchet joint. Preferably, the first half of a ratchet mount  78  and the third half of a ratchet mount  94  are sized and shaped identically so the fourth half of a ratchet mount  96  is can be connected to the both of them. 
         [0044]    The fourth half of a ratchet mount  96  is attachable to the extension pole  36  in that the fourth half of a ratchet mount  96  can be permanently or removeably joined to the extension pole  36 . As shown in  FIG. 6 , the fourth half of a ratchet mount  96  has internal threads to join with an extension pole  36  that has external threads. Nonetheless, any junction capable of withstanding the forces exerted between the extension pole  36  and the fourth half of a ratchet mount  90  during use of the filter-changing system  20  is acceptable. 
         [0045]    If the mounting means  38  is a pivotable joint or a rotational joint, the joint is preferably lockable so the filter-grabbing device  32  does not freely pivot or rotate when the filter-changing system  20  is used. In the preferred mounting means  38 , the clevises are made from a pliable material, such as plastic, that will deform when pressure is applied. As such, when the wing nuts are tightened the clevis arms compress against the clevis mounts, preventing the first and second clevis joints from pivoting. In the alternative mounting means  38  from  FIG. 6 , the gripping grooves engage each other when the ratchet wing nuts are tightened, thereby preventing the first and second ratchet joints from pivoting. 
         [0046]      FIGS. 7 through 10  show different locations of the preferred holding means  38  present in the preferred embodiment. The holding means  38  creates a force that holds the vent door  26  closed, yet, due to the nature of the holding means  32 , will allow the force to be overcome when the vent door  26  is pulled with the filter-grabbing device  32 . As noted, the preferred embodiment of the holding means  38  is a plurality of magnets mounted on the return-air vent  22 . The magnets may be mounted to the vent door  26 , as shown in  FIGS. 8 &amp; 10 , or they may be mounted to the vent perimeter  24  of the return-air vent  22 , as shown in  FIGS. 7 and 9 . Regardless of their location on the return-air vent  22 , the magnets must be positioned so their magnetic force holds the vent door  26  closed. 
         [0047]    It also should be noted that other holding means  32  could be used to hold the vent door  26  closed. For example, a ball detent, or some other kind of detent, may be mounted on the vent door  26  or the vent perimeter  24 . If mounted on the vent door  26 , the vent perimeter  24  has corresponding structure for the ball detent to enter into so the vent door  26  is held closed. On the other hand, if the ball detent is mounted on the vent door  26 , the vent perimeter  24  has corresponding structure for the ball detent to into so the vent door  26  is held closed. 
         [0048]      FIGS. 11 through 13  illustrate the functionality of the preferred embodiment of the present invention. In  FIG. 11 , the vent door  26  is shown in a “closed” position, with the preferred holding means  38  holding the vent door  26  at the vent perimeter  24  of the return-air vent  22 . Two teeth from the plurality of teeth  48  are inserted into the grill louvers  28  on the vent door  26 . Using the extension pole  36 , the user pulls the vent door  26  away from the magnetic force of the preferred holding means  32  and the vent door  26 , which is attached to the vent perimeter  24  with hinges  30 , swings from the vent perimeter  24  of the return-air vent  22 . 
         [0049]    As the vent door  26  swings from the vent perimeter  24 , there is a tendency for the teeth that are inserted into the grill louvers  28  to get caught in the louvers. This tendency is attributed to the fact that the angle of insertion of the teeth into the grill louvers  28  changes as the vent door  26  swings open. To combat this tendency, the kicker plates  50  are present in the preferred embodiment. The downward angle of the kicker plates  50  from the holding plate  40  causes the inserted teeth to push out of the grill louvers  28  as the vent door  26  swings open and the angle of insertion changes. 
         [0050]    With the vent door  26  open, an air filter  102  is exposed but remains in place because the blower is running. In its most basic form, the air filter  102  is made from a filter media  104  and a support structure  106 . The filter media  104  filters dust and other particles from the external air as it passes through the filter media  104  and into the HVAC system. The filter support structure  106  is external to the filter media  104  and prevents the filter media  104  from being sucked into the HVAC system. In this regard, when dust and other particles accumulate on the filter media  104 , a vacuum forms between the filter media  104  and the blower in the HVAC system. Without the support structure  106 , the vacuum created by the blower on the filter media  104  would cause the filter media  104  to be sucked into the HVAC system. 
         [0051]    To remove the air filter  102 , teeth from the plurality of teeth  48  on the filter-grabbing device  32  are inserted between the filter media  104  and the support structure  106  on the air filter  102 . In  FIG. 12 , the support structure  106  is only at the perimeter of the filter media  104 . In  FIG. 13 , the support structure  106  is at the perimeter around the filter media  104  and includes cross members that span the filter media  104 . 
         [0052]    In  FIG. 13 , the teeth from the plurality of teeth  48  are shown inserted between two cross members of the support structure  106 , and shows the functionality of the predetermined distances between the sets of teeth. Though not required, the teeth on the filter-grabbing device  32  will preferably be inserted at the center of one side of the air filter  102 , which allows the air filter  102  to be better balanced on the holding plate  40  of the filter-grabbing device  32 . The configuration of the cross members in the air filter  102  can vary from filter to filter, and as shown in  FIG. 13 , the cross members of the support structure  106  may interfere with the teeth&#39;s insertion. As such, the teeth on each side  46  of the holding plate  40  are spaced apart from each other at different distances to address the different configurations and designs of air filters. 
         [0053]    Although not shown, once the teeth are inserted between the filter media  104  and the support structure  106 , the dirty air filter  102  is pulled from the vent perimeter  24  of the return-air vent  22 . With the teeth still inserted between the filter media  104  and the support structure  106 , the removed air filter  102  balances on the top surface  42  of the holding plate  40 . The user brings the dirty air filter  102  down from its elevated position, grabs the air filter  102  by hand, and removes the air filter  102  from the filter-grabbing device  32 . 
         [0054]    The user then places a clean air filter on the filter-grabbing device  32 , lifts the clean filter toward the elevated return-air vent  22 , and allows the blower to suction the clean air filter into place. After the clean air filter is in place and being held in the return-air vent  22  by the blower, the filter-grabbing device  32  is removed. Then, using the curved end  56  that is present in the preferred embodiment, the vent door  26  is pushed back into the “closed” position and the holding means  38  holds it there. 
         [0055]    Finally, it should be noted that the preferred mounting means  38 , allows the angles between the filter-grabbing device  32  and the extension pole  36  to be changed. The ability to changes the angle of the filter-grabbing device  32  with respect to the extension pole  36  facilitates use of the present invention when access to the return-air vent  22  is restricted by a piece of furniture or other heavy object located under the return-air vent  22 . In this regard, if the piece of furniture were directly under the return-air vent  22 , the user would have to maneuver the filter-grabbing device  32  so the holding plate  40  and the teeth extending therefrom were properly oriented for insertion into the grill louvers  28  and into the dirty air filter  96 . With the preferred mounting means  38 , as well as other pivotable or rotateable mounting means  38 , the filter-grabbing device  32  could be properly oriented for insertion of the teeth without extensive maneuvering. 
         [0056]    Although the present invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon the reference to the above-description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.