Abstract:
The present invention is directed towards a sensor including, inter alia, a body having first and second spaced-apart apertures, the first aperture having a shape producing an audible noise upon a fluid passing therethrough; a piston positioned within the body; and a chamber having an additional fluid disposed therein, with a volume of the additional fluid placing the piston between first and second positions, the first position impeding the first volume of fluid and the second position allowing the first volume of fluid to pass through the first aperture.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     The present invention is directed towards an audible sensor. More specifically, the present invention is directed towards a sensor for an air filter to indicate a replacement thereof.  
         [0002]     Heating and cooling systems for houses and other dwellings and for at least some commercial establishments include a system for transmitting heated or cooled air throughout the dwelling or commercial establishment. These systems for transmitting heated or cooled air also include filtration equipment for removing particulate matter from the heated or cooled air and this filtration equipment, particularly for dwellings, normally includes one or more mechanical filters formed from fibrous materials.  
         [0003]     These filter materials serve the function of mechanically blocking particulate matter that is in the air flowing in circuitous paths through the filter material. The particulate matter becomes attached to individual fibers and, over a period of time, progressively restricts the air flow paths. This trapped particulate matter simultaneously causes a reduction of the air flow rate through the filter.  
         [0004]     This reduced air flow rate reduces the efficiency of the heating or cooling system and the effective heating or cooling of the dwelling or commercial establishment. The partially clogged filter also causes increased back pressure to be applied to the blower or fan which generates the air flow and this back pressure increases the work that must be performed and the energy consumed by the blower or fan unit. The resulting increased load increases the wear rate of the moving parts in the heating or cooling system and also results in increased operating costs.  
         [0005]     In order to determine when an air filter needs to be changed, a person normally must gain access to the filter. The filter must then be removed and visually inspected. If it is evident through this visual inspection that there is a significant build up of particulate matter on the outside surface of the air filter it is usually replaced with a new filter. This procedure has various deficiencies. This procedure means that the air filter must be periodically checked in order to determine when the filter needs to be changed. This is time consuming and can often result in dirty filters not being changed on time due to the failure to remember to check the filter.  
         [0006]     U.S. Pat. No. 4,215,646 to Williams describes a whistle audibly responsive to extremely small pressure differentials. The whistle comprises an inlet portion of a first diameter and an outlet portion of a second diameter. The whistle produces an audible sound when a pressure differential exists across the inlet and outlet portions.  
         [0007]     U.S. Pat. No. 5,352,255 to Taft describes a noise maker apparatus for an air filter. The noise maker has a housing having a hole and a weighted member in resilient relationship over the hole. The weighted member is responsive to a pressure change across the hole.  
         [0008]     However, the replacement of air filters may be a function of time. More specifically, air filters may be replaced based upon a manufacturer&#39;s suggested time. To that, there is a need for an improved sensor for air filters.  
       SUMMARY OF THE INVENTION  
       [0009]     The present invention is directed towards a sensor including, inter alia, a body having first and second spaced-apart apertures, the first aperture having a shape producing an audible noise upon a fluid passing therethrough; a piston positioned within the body; and a chamber having an additional fluid disposed therein, with a volume of the additional fluid placing the piston between first and second positions, the first position impeding the first volume of fluid and the second position allowing the first volume of fluid to pass through the first aperture. These and other embodiments are described more fully below. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view showing a sensor positioned on an air filter in accordance with the present invention;  
         [0011]      FIG. 2  is a side view of the sensor shown in  FIG. 1 , in accordance with a first embodiment of the invention, the sensor having a piston placed in a first position;  
         [0012]      FIG. 3  is a side view of a portion of the sensor shown in  FIG. 2 , the sensor having a removable portion positioned thereon;  
         [0013]      FIG. 4   a  is a front view of the sensor shown in  FIG. 2 , with a chamber of the sensor positioned on a first side of the sensor;  
         [0014]      FIG. 4   b  is a front view of the sensor shown in  FIG. 2 , with a chamber of the sensor positioned on a second side of the sensor;  
         [0015]      FIG. 5  is a side view of a portion of the sensor shown in  FIG. 2 , the sensor having a spring;  
         [0016]      FIG. 6  is an exploded view of a portion of the sensor shown in  FIG. 2 ;  
         [0017]      FIG. 7  is a side view of the sensor shown in  FIG. 2 , with the piston of the sensor placed in a second position;  
         [0018]      FIG. 8  is a side view of the sensor shown in  FIG. 1 , in accordance with a second embodiment of the invention, the sensor having a piston placed in a first position;  
         [0019]      FIG. 9  is a side view of the sensor shown in  FIG. 2 , with the piston of the sensor placed in a second position; and  
         [0020]      FIG. 10  is a side view of the sensor shown in  FIG. 1  in accordance with a third embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     Referring to  FIG. 1 , there is shown an air filter  10  having a sensor  12 , described in further detail below, positioned thereon. Air filter  10  may be any air filter commonly used in a HVAC system (heating, ventilation, and air conditioning system) (not shown) to filter particular matter therefrom. Air filter  10  comprises a frame  14  having a filter material  16  disposed therein. Filter material  16  may include materials including but is not limited to, polyurethane foam and polypropylene. In a further embodiment, sensor  12  may be positioned within frame  14  or within filter material  16 .  
         [0022]     To that end, air filter  10  may be exposed to a flow of fluid from the HVAC system (not shown). The flow of fluid may have contained therein, inter alia, particulate matter. To that end, air filter  10  filters the flow of fluid such that the particulate matter becomes entangled with and lodged upon filter material  16 . However, over a period of time, an increasing quantity of particulate matter becomes entangled with and lodged upon filter material  16  causing detrimental effects upon air filter  10 . Such effects include, inter alia, reducing an air flow rate through air filter  10 . As a result, an efficiency of the HVAC system is reduced, which is undesirable. To prevent the aforementioned detrimental effects, air filter  10  may be replaced periodically. To that end, described below is a sensor to provide a signal indicating a replacement of air filter  10 .  
         [0023]     Referring to  FIG. 2 , in a first embodiment, sensor  12  comprises a body  18  having a section  20  and spaced-apart first and second ends  22  and  24 . In a further embodiment, section  20  may comprise a cavity (not shown) positioned therein. Second end  24  may comprise a protrusion  26 . Protrusion  26  facilitates coupling sensor  12  to air filter  10  and more specifically, coupling sensor  12  to filter material  16 , shown in  FIG. 1 . In a further embodiment, second end  24  may comprise a plurality of protrusions  26 . In a further embodiment, second end  24  may comprise any coupling element to couple sensor  12  to air filter  10 , with such coupling elements including, but is not limited to, pins, barbs, clips, clamps, tape, and adhesives. First end  22  comprises a cavity  28 . As shown, cavity  28  comprises a rectangular geometrical shape, however cavity  28  may comprise any desired geometrical shape.  
         [0024]     Sensor  12  further comprises apertures  30  and  32  having a pathway  34  extending therebetween. Aperture  30  may be positioned proximate to first end  22  and aperture  32  may be positioned adjacent to second end  24 . Pathway  34  may have a fluid  36  flowing therein. Aperture  30  may be in superimposition with cavity  28  and may comprise an angled portion  37 . In a further embodiment, aperture  30  may comprise a removable portion  40 , shown in  FIG. 3 , in superimposition therewith. Removable portion  40  may be formed from an adhesive tape.  
         [0025]     Positioned upon a side  38  of body  18  is a chamber  42 . Chamber  42  may be formed from materials including but not limited to polypropylene, high density polyethylene, glass, ceramic, cardboard, and metal. In a further embodiment, chamber  42  may be positioned upon side  43  of body  18 , as shown in  FIG. 4   a,  or upon side  45  of body  18 , as shown in  FIG. 4   b.  Chamber  42  may be any desired geometrical shape including but is not limited to, cylindrical and rectangular. Chamber  42  may comprise a bladder  44  having a fluid  46  disposed therein. In a further embodiment, fluid  46  may be disposed within chamber  42  without bladder  44 . Positioned between bladder  44  and body  18  is a plate  48 . In a further embodiment, a spring  50 , shown in  FIG. 5 , may be positioned between plate  48  and body  18 . Spring  50  may exert a force F 1  upon plate  48 . Force F 1  depends upon, inter alia, a spring constant of spring  50 . As shown, positioned on a side  52  of chamber  42  is a hole  54  having a wick  56  positioned therein. In a further embodiment, hole  54  and wick  56  may be positioned upon any desired location of chamber  42 . Wick  56  may comprise a first segment  58  and a second segment  60 , shown more clearly in  FIG. 6 . First segment  58  may be in contact with fluid  46 , and thus place wick  56  in fluid communication with fluid  46 . Wick  56  may be formed materials including but is not limited to polyethylene, polypropylene, polyesters, polypropylene, glass-sintered fibers, porous ceramic, carbon fiber, sintered carbon, wood, compressed wood composites, cotton, linen, nylon, polyamides, rayon, and polyacetates.  
         [0026]     Positioned within section  20  of body  18  is a aperture  62 . Aperture  62  may be in superimposition with chamber  42 , and more specifically, in superimposition with an aperture  64  positioned on side  38  of body  18 . Attached to plate  48  is a piston  66 . As shown, piston  66  comprises a cylindrical shape, however, piston  66  may comprise any geometrical shape desired. In a further embodiment, piston  66  may be contiguous with plate  48 . In still a further embodiment, plate  48  may comprise a plurality of pistons  66  attached thereto.  
         [0027]     As shown, piston  66  may be placed in a first position. More specifically, piston  66  may be placed to extend thru aperture  64  and pathway  34  to be positioned within aperture  62 . Piston  66  may be placed in the first position as a result of a force F 2  exerted by fluid  46  upon plate  48 . A magnitude of force F 2  depends upon, inter alia, a volume of fluid  46 . Plate  48  may function to spread force F 2  equally about piston  66 . To that end, the aforementioned flow of fluid  36  may be impeded as a result of piston  66  being positioned in the first position. More specifically, piston  66  may be placed transverse to the flow of fluid  36 .  
         [0028]     Referring to  FIGS. 2 and 6 , to that end, fluid  46  may have an evaporation rate associated therewith. The evaporation rate of fluid  46  may depend upon, inter alia, a composition of fluid  46 . Fluid  46  may comprise such composition including but not limited to, water, water-based liquids, and oil-based liquids. In a further embodiment, fluid  46  may comprise a fragrant-containing composition. The fragrant-containing composition may be any commercially available fragments such as those available from Save On Scents, Inc. located in Brooklyn, N.Y. In STILL a further embodiment, fluid  46  may comprise a disinfectant-containing composition.  
         [0029]     To that end, as mentioned above, fluid  46  may be in fluid communication with wick  56 . More specifically, first segment  58  of wick  56  absorbs a portion of fluid  46 , with the portion of fluid  46  diffusing into second segment  60  of wick  56 . The portion of fluid  46  disposed in second segment  60  may then evaporate into the surrounding environment. This process results in an evaporation/absorption process that continues until bladder  44  may be substantially absent of fluid  46 . In a further embodiment, wick  56  may be in electrical communication with a heating source (not shown). The heating source (not shown) may facilitate evaporation of the portion of fluid  46  disposed in second segment  60  of wick  56 .  
         [0030]     To that end, as a result of a portion of fluid  46  evaporating thru wick  56 , a volume of fluid  46  may decrease. As mentioned above, force F 2  may be dependent upon the volume of fluid  46 . As a result of the decrease in the volume of fluid  46 , a magnitude of force F 2  upon plate  48  and piston  66  may decrease, and thus, plate  48  and piston  66  may translate towards chamber  42 . In a further embodiment, the reduction of the volume of fluid  46  may create a vacuum within chamber  42 , and thus facilitate the translation of plate  48  and piston  66  towards chamber  42 .  
         [0031]     Referring to  FIG. 7 , over a predetermined amount of time, a volume of fluid  46  may evaporate such that piston  66  may be placed in a second position. More specifically, piston  66  may be positioned within chamber  42  such that piston  66  does not extend thru pathway  34  and is not positioned within aperture  62 . As a result of placing piston  66  in the second position, the flow of fluid  36  may substantially translate through pathway  34  and exit body  18  through aperture  30 . As mentioned above, aperture  30  comprises an angled portion  37 . To that end, fluid  36  may contact angled portion  37 , causing a portion of fluid  36  adjacent to angled portion  37  to vibrate and produce an audible noise, commonly referred to as a “whistle.” Furthermore, a geometrical shape of cavity  28  may be altered such that a desired frequency of the audible noise may be obtained and/or to increase a magnitude of the audible noise. In a further embodiment, sensor  12  may comprise a reed whistle (not shown) that may produce the audible noise in response to fluid  36  passing therethrough.  
         [0032]     To that end, the aforementioned predetermined amount of time may be dependent upon, inter alia, the evaporation rate of fluid  46 . As a result, the composition of fluid  46  may be chosen such that the sensor  12  may produce the aforementioned audible noise after a desired period of time.  
         [0033]     Referring to  FIG. 8 , in a second embodiment, piston  66  may be positioned adjacent to first end  22  of body  18 . As a result, when piston  66  is placed in the first position, piston  66  may substantially be in superimposition with aperture  30 , and thus, impede a flow of fluid  36  thru pathway  34 .  
         [0034]     Referring to  FIG. 9 , analogously to the above-mentioned, piston  66  may be placed in the second position as a result of a decreasing volume of fluid  46 , and thus, expose aperture  30 . Fluid  36  may then flow through pathway  34  to exit through aperture  30  and produce the audible noise, analogous to the above-mentioned.  
         [0035]     Referring to  FIG. 10 , in a further embodiment, cavity  28  may comprise a fluid  68 . Fluid  68  may have an evaporation rate associated therewith. The evaporation rate of fluid  68  may depend upon, inter alia, a composition of fluid  68 . Fluid  68  may comprise such compositions as those mentioned-above with respect to fluid  46 , shown in  FIG. 2 . Cavity  28  may further comprise a noise-making device  70  positioned therein. To that end, analogous to fluid  46  mentioned above with respect to  FIG. 2 , over a predetermined period of time, a volume of fluid  68  may evaporate, and thus, fluid  68  may be substantially absent from cavity  28 . To that end, fluid  36  may flow thru pathway  34  and contact noise-making device  70  such that noise-making device  70  may produce an audible noise. Noise-making device  70  may comprise a bell, a chime, or a rattle. Further, the composition of liquid  68  may be chosen such that the sensor  12  may produce the aforementioned audible noise after a desired time.  
         [0036]     The embodiments of the present invention described above are exemplary. Many changes and modifications may be made to the disclosure recited above, while remaining within the scope of the invention. Therefore, the scope of the invention should be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.