Abstract:
An insect trap apparatus includes a trap housing having at least one inlet and at least one outlet. A source of suction is located within the housing and is in fluid communication with the inlet for drawing insects through the inlet. Insects are caught in a trap cup that is in fluid communication with the inlet. The trap cup has a screen having at least one crest and at least one trough.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to an insect trap apparatus that uses suction to draw insects into the trap. More specifically, this invention relates to an improved trap cup to be used in such an insect trap apparatus.  
         [0002]     Suction-type insect traps are well known in the art. Effective prior art suction traps use heat, water vapor, chemical attractants and combinations thereof to lure insects to the trap apparatus. In operation, an outlet stream containing the various attractants is released from the apparatus, attracting insects to the vicinity of the apparatus. When the insects get within a capture zone, a fan or other suction source draws large amounts of air and the insects entrained therein into a trap inlet. The insects are filtered from the air before it exits through an outlet. After the insects are collected within the insect trap, they are dehydrated, killed or stored until removal.  
         [0003]     Some insect traps utilizing a sieve or filter, such as a trap cup or a net, face several design problems. First, there is limited space in which to deposit and hold the insects. Consumers are not only bothered with frequently emptying the trap, but they may doubt the efficacy of the trap if only a few insects fall from the trap cup when it is emptied. As the insects accumulate in the trap cup, the surface area for allowing the air through the cup decreases. The entire floor of the cup is blocked when a monolayer of insects is collected. To gather a large number of insects before the trap cup is emptied, the trap cup needs to have porous sidewalls and should be fairly deep to allow air passage through the sidewalls of the trap cup.  
         [0004]     Second, as the surface area becomes blocked with insects, less surface area is available for air flow through the trap cup. When the trap cup becomes filled with of insects, airflow through the insect trap apparatus is stifled. Although the fan continues to circulate air, power is wasted recirculating the air within the trap, rather than pushing it through the trap cup. If the fan motor has no thermal protection, it will eventually overheat from heat build-up in the recirculating air and could burn out. More likely, a heat sensor will shut the fan off before it overheats. In either case, the immediate result is that the fan stops working and the trap cup must be emptied before the trap again becomes operational.  
         [0005]     The resultant block in airflow not only increases motor temperature, but reduces airflow as the available work from the fan converts from flow to pressure to overcome the added resistance. This reduction in airflow reduces the suction, lessening the effectiveness of the trap.  
         [0006]     Third, the insect trap is often positioned inside, at or near the bottom of the housing, making viewing or emptying the trap inconvenient for the user. Some traps require the user to perform multiple steps, including shutting down the unit, before they can even check the level of insects in the trap. The trap must be shut down, the housing must be opened, a mesh bag removed, emptied and replaced, the housing closed and the trap restarted to empty the trap of mosquitoes.  
         [0007]     Thus, there is a need in the art for a trap cup in an insect trap apparatus that is convenient for the user to empty and can hold a large capacity of insects without blocking the airflow through the trap.  
       SUMMARY OF THE INVENTION  
       [0008]     The present insect trap apparatus features an improved trap cup. Emptying insects from the unit is easy and convenient for the user since the trap is located exterior to the housing and is easily positioned. Additionally, the trap cup has a large capacity for insects while maintaining good airflow.  
         [0009]     More specifically, the present trap cup includes a wave-shaped screen having at least one trough and at least one crest. Preferably the wave is in the screen at the bottom of the trap cup, where insects collect in the one or more troughs and air flows freely through the one or more crests of the wave.  
         [0010]     Additionally, the present trap apparatus includes a trap housing having at least one inlet and at least one outlet. A source of suction is associated with the housing and is in fluid communication with the inlet for drawing air and insects through the inlet. Insects are caught in the wave screen that is associated with the housing and in fluid communication with the inlet.  
         [0011]     Improved airflow through the present insect trap overcomes many of the disadvantages of the prior art. The airflow can be directed through the trap so that insects can be separated in a location where they are conveniently accessed by the user for disposal. Versatility in air flow also allows receptacles for supplemental chemical attractants to be conveniently placed in areas where there is space for multiple receptacles to accommodate a variety of attractant sizes or types.  
         [0012]     Use of the present wave screen makes efficient use of vertical space for both insect storage and airflow. Without making the trap cup larger, the effective surface area is increased considerably. As they are trapped, insects are mounded in the troughs of the wave and take up less surface area than if they were allowed to scatter over a flat surface. Protrusion of the crests above the mounds of insects provides surface for airflow in addition to that available through the sidewall.  
         [0013]     The present wave screen is also partially self-cleaning and requires emptying less frequently than a conventional flat screen. Constant flow of air through the trap cup dehydrates and decomposes the insects caught in the trap cup. As the collected insect remains form mounds in the wave troughs, the weight of the collection of insects crushes those at the bottom of the mound, allowing the small pieces to fall through the screen and blow away in the breeze or drop unnoticeably into the grass.  
         [0014]     Collection of insects in the trough of the wave provides reassurance to the user that the trap is operating properly. Where many insects are scattered over a large surface area, it may appear to the consumer that few insects are being caught by the trap. This perception may cause the user to be concerned that the trap is not operating correctly or that the trap is ineffective in catching insects. Concentration of the same number of insects in a smaller space makes it appear that significant numbers of insects have been captured, assuring the consumer that the trap is operating effectively.  
         [0015]     The structure of the present insect trap also makes it more economical to manufacture. Conduits for fluid transfer are molded into other structural elements, providing fewer parts that need to be molded, stored and assembled. Less manufacturing and assembly labor can be used, since fewer parts are made and assembled. The cost of making the molds is reduced. Thus, the present insect trap can be more efficiently made than other popular suction traps, resulting in savings to both the manufacturer and the consumer. 
     
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of one embodiment of the present insect trap mounted to a cart;  
         [0017]      FIG. 2  is a fragmentary side plan view of the trap head and trap cup;  
         [0018]      FIG. 3  is a bottom plan view thereof;  
         [0019]      FIG. 4  is a fragmentary bottom perspective view thereof;  
         [0020]      FIG. 5  is a bottom perspective view of the trap cup and wave screen;  
         [0021]      FIG. 6  is a top perspective view thereof;  
         [0022]      FIG. 7  is a top plan view of the present trap cup and wave screen;  
         [0023]      FIG. 8  is a front view of the trap cup and wave screen of  FIG. 7 ;  
         [0024]      FIG. 9  is a side view of the trap cup and wave screen of  FIG. 7  and  
         [0025]      FIG. 10  is a bottom perspective view of an alternate embodiment of the present trap cup having a mesh screen. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0026]     Referring to  FIGS. 1, 2  and  3 , a wave screen, generally designated  10 , is fitted to a trap cup, generally designated  12 , that is releasably attached to an insect trap, generally designated  14 , that utilizes suction to immobilize insects. A source of suction, such as fan  16  (shown hidden in  FIG. 3 ), draws an inflow of air  20  and insects into the insect trap  14  at a suction inlet  22  between a cover  24  and a trap head  26 . The air inflow  20  travels through the interior of the trap head  26 , past the fan  16 . Exhaust air  28  from the fan  16  is blown through an exhaust opening  30  in a bottom or lower end  31  of the trap head  26  and through the trap cup  12  which substantially closes the opening  30 . All of the exhaust air exits through the wave screen  10 , which acts as a sieve to catch the insects, but allows the air to freely flow through it. The suction-type insect trap  14  is but one embodiment of a trap that effectively utilizes the wave screen  10 , and it is exemplified in the following discussion. However, it is contemplated that the wave screen  10  is useful with other types of insect traps. Unless otherwise noted, directional references contained herein are intended to refer to the insect trap  14  or the trap cup  12  when oriented as shown in  FIGS. 1 and 2 .  
         [0027]     The present insect trap  14  burns propane fuel  32  supplied by a fuel line  34  from a fuel tank  36  (both shown in phantom) to generate combustion products and to provide heat to a thermoelectric generator (not shown) that powers electrical devices, such as the fan  16  and or a light  40  ( FIG. 1 ) that indicates when the unit is operating. The inlet air  20  and the fuel  32  are mixed in a combustion chamber (not shown) where they are burned to produce combustion products  42 , including carbon dioxide, water vapor and heat. These combustion gases  42  exit the insect trap  14  in a location to which the insects are intended to be attracted. The combustion gases  42  are either combined with the exhaust air  28  and sent through the wave screen  10 , or they exit through one or more separate outlets  44 . The thermoelectric generator, which generates electricity from the temperature differential across junctions utilizing the Seebeck effect, is well known in the art. In the alternative, electrical power can be obtained directly from household current.  
         [0028]     The insect trap  14  is preferably mounted to a cart, generally designated  46  ( FIG. 1 ), so that it may be conveniently moved from place to place. Typically, the cart  46  includes a frame  50 , a generally vertically projecting post  52  upon which the insect trap  14  is mounted, a handle  54 , a ring or support  56  for the fuel tank, an axle  58  with one or more wheels  60  and one or more feet  62 . The cart  46  is shown as one type of supporting for the insect trap  14 , but is not important to the function of the wave screen  10 . It is contemplated that other insect traps are adaptable for use with the present wave screen  10 .  
         [0029]     As seen in  FIGS. 3 and 4 , the trap cup  12  including the wave screen  10  is releasably mounted to the bottom  31  of a trap head housing  66  forming an exterior of the trap head  26 . However, the trap cup  10  is mountable to any portion of the insect trap  14  where it is in a position to receive the suction air  20  and entrained insects before they exit the insect trap  14 . Preferably, the trap cup  12  is located for the convenience of the user when emptying, or when checking the trap cup to determine if it needs to be emptied.  
         [0030]     Any fastening technology for releasably mounting the wave screen  10  or trap cup  12  to the trap head  26  is suitable. Seen best in  FIGS. 3 and 4 , one preferred mounting system includes a lip  68  on the trap cup  12  that is supported by one or more channels or brackets  70  on the trap head  26 . Each of the channels  70  is optionally “L” or “C” shaped and is preferably formed as an integral part of the trap housing  66 . As an alternative, the channes  70  are made separately and attached to the trap housing  66  by any suitable fastener. The lips  68  are preferably located on opposing sides of the trap cup  12 , and are preferably a simple protrusion from each side of the trap cup. On the trap housing  66 , the preferably two channels  70  are positioned in spaced, generally parallel arrangement to receive the lips  68 , supporting the trap cup  12  between them. To remove the trap cup  12 , the user need only grasp the trap cup  12  and slide it in a direction parallel to the channels  70 . The exact shape of the lips  68  and the channels  70  are not important, only that they matingly engage to allow the trap cup  12  to be releasably attached to the trap housing  66 .  
         [0031]     Other means for attaching the trap cup  12  to the trap housing  66  are equally useful. The trap cup  12  could be attached using a press fit or friction fit closure, magnetic attraction, a lock or latch, a hinge, any type of fastener including pins, hooks or hook and loop fasteners. Attachment of the trap cup  12  is optionally facilitated by sliding the trap cup, twisting it, turning it, rotating it or squeezing it. Any structure for attaching the trap cup  12  to the trap housing  66  is suitable that permits the trap cup  12  to easily be emptied of insects.  
         [0032]     As shown in  FIGS. 5 and 6 , the wave screen  10  includes at least one trough  74  and at least one crest  76  forming at least one wave  80 . It is important to have a continuously sloping shape to the wave  80  so that the insects slide down into the trough  74  and air continues to flow through the wave crest  76 . Regardless of where the insect intersects the wave screen  10 , in the orientation shown in  FIG. 1 , gravity will put it downward so that over time, a mound of insects collects in the bottom of the trough  74 . Compared to a flat bottom trap cup, a relatively large number of insects can be collected without noticeably inhibiting airflow through the wave screen  10 . Formation of a mound of insects also reassures the user that the trap  14  is working properly and is catching a significant number of insects.  
         [0033]     Although the wave screen  10  is optimally shown as being positioned on the bottom of a preferably rectangular, square or otherwise polygonal trap cup  12 , the precise shape of the trap cup is not critical and could also be cylindrical. It is also contemplated that the amplitude of the wave  80  could project in any direction, besides the generally vertical one shown. If the portion of the wave  80  extends laterally outward from the center of the trap cup  12 , the trough  74 , the crest  76  of the wave  80  would extends inwardly toward the trap cup  12  center. In that orientation, after the insects fill the bottom of the trap cup  12 , the airflow will exit through sidewalls  82  of the trap cup  12 . Insects will tend to accumulate at the sidewall  82  and be pushed toward the troughs  74 , leaving the crests  76  open to airflow. Although not as effective as when the wave screen  10  is on the bottom of the trap cup  12 , the use of waves  80  around the sidewall  82  of the trap cup  12  will improve airflow through it. As shown, the sidewalls  82  are solid, however, the use of sidewalls through which air flows is contemplated, provided that the trapped insects are still retained.  
         [0034]     A further advantage of piling up the insects at the bottom of the trough  74  is that it encourages natural decomposition of the insect remains. Continuous flow of air over the insects dehydrates them, leaving the remains dry and brittle. When the insects form a mound, the weight of the mound on the remains at the bottom of the trap causes the remains to disintegrate quickly and fall through the tiny openings in the wave screen  10 .  
         [0035]     The wave screen  10  can be made from any material that will maintain openings of an appropriate size to both trap insects and encourage airflow. Preferred materials are those that hold up in the outdoors, such as polymers or plastics, including, but not limited to polyethylene, polypropylene, polyimides, nylon, poly(methyl methacrylates), acrylics, acetates and polycarbonates. Metal mesh screens are suitable in the wave screen  10 , particularly those that are not susceptible to rust, such as aluminum or stainless steel. Fabric mesh sieves are also useful in the wave screen  10 , particularly those made of synthetics, such as nylon mesh screens. If the fabric is soft and pliable, supports (not shown) may be needed to hold the fabric in the wave  80  shape.  
         [0036]     As shown in  FIGS. 7, 8  and  9 , the wave screen  10  preferably is formed from a number of rigid, parallel elements  86  in the shape of “W” shaped plastic slats. The screen  10  wave sieve can be made of a mesh where the parallel sieve elements  86  are cross-linked; however, the parallel elements are useful alone if they are rigid enough to screen the insects. Cross-linked sieve elements  86 ′ in the form of a mesh screen are shown in the alternate embodiment  10 ′ shown in  FIG. 10 . Other embodiments of the wave screen  10  that are contemplated include a perforated plate, plastic or aluminum mesh screens, or any screen or sieve that separates insects from the intake air.  
         [0037]     The sidewalls  82  and lip  68  are part of a trap cup frame  90  that also includes an endwall  92 . It is contemplated that the cup frame  90  and the wave screen  10  can be a single, unitary trap cup  12 , or that the wave screen  10  and trap frame  90  can be at least two separate pieces. Wave screen  10  is attachable as a unit to the trap cup frame  90  by suitable mans, including adhesives, fasteners, sand______ the screen between frame pieces and the like. Utilizing a separate wave screen  10  facilitates its removal and replacement if desired, such as if the wave screen  10  should become damaged. However, in the preferred embodiment shown, the trap cup  12  is made of a plurality of sections  94  that include elements of both the trap cup frame  90  and the wave screen  10 . The sections  94  are optionally releasably attached or permanently attached to each other. Preferably, each of the sections  94  is identical to each of the other sections for ease in manufacturing and assembly. In the embodiment shown, the trap cup  12  is formed of two sections  94 , preferably identical, that releasably attach to each other by means of a spring latch  96  and a catch  98 . Each endwall  92  is constructed from a latch end  100  of one section  94  releasably connected to the catch end  102  of another section  94 .  
         [0038]     Insects are removed from the suction air by the wave screen  10 . The overall properties of the wave screen  10  will depend on the insects targeted to be caught and the volume of insects to be accommodated. Openings  104  in the wave screen  10  must be sufficiently small that the insects of interest cannot pass through it, but large enough to facilitate air through the wave screen  10 . Thus, if the insect trap  14  is targeting gnats or no-see-ums, the wave screen  10  will be finer than if mosquitoes or flies are the intended target insects. The total surface area of the wave screen  10  is adjustable to provide sufficient air flow through the wave screen for a particular insect capacity. Preferably, the wave screen  10  is located at the exhaust opening  30 , substantially closing the opening to insects but allowing the air to exit from the insect trap  14 .  
         [0039]     Varying the shape of the waves  80  in the wave screen  10  also changes airflow dynamics. When deeper waves  80  are used, the sides of the waves are steeper and the insects tend to pile in a more compact mound. The increase in vertical space is usable for increased airflow, since more open surface area is available at the wave crest  76  for the air to exit the wave trap. Although the crests  76  and troughs  78  are shown as being of uniform shape, it is contemplated that they could vary in any useful manner. For example,  FIG. 8  shows two troughs  78  of uniform shape, but it is acceptable to have one trough  78  be deeper than another or have a different radius of curvature. The center crest  76  need not reach the level of the bottom of the trap cup  12 , or it can extend upwards past the top of the trap cup and into the trap head  26  itself. Any configuration of shapes of the crests  76  and troughs  78  can be used that supplies sufficient storage space for insects and airflow through the crests.  
         [0040]     Best shown in  FIG. 8 , although the wave screen  10  is shown and described as part of a trap cup  12  having a height H, it is contemplated that H could be negligible and that the wave screen  10  be releasably secured directly to the trap head  26 . Where the wave screen  10  provides sufficient storage space for insects in the troughs  78  and permits airflow through the crests  76  without excessive air pressure, there is no need for the sidewalls  82 . Preferably the wave screen  10  has enough of a frame  90  to assist the wave screen  10  to hold its shape, however, even the frame is optional where the wave screen  10  is designed to hold insects and be releasably attached to the insect trap  14  on its own. Other features of the trap cup  12 , such as the manner in which ways it is releasably attached to the trap head  26 , are then directly applicable to the wave screen  10 .  
         [0041]     In operation, the wave screen  10  and the associated trap cup  12  are attached to the insect trap  14  and the trap is started up. Suction from the fan draws inlet air  20  and entrained insects into the trap head  26  through an inlet  22 . Before exiting the trap head  26 , the air is screened or filtered to remove the insects, and the air  20  is exhausted to the environment. As the insects are caught by the wave screen  10 , they slide down the smooth surface of the wave  80  and form a mound in the trough  74 . Air exhausts through the crest  76  of the wave  80  even when the troughs  74  are blocked with insects. Periodically, the wave screen  10  is emptied to remove insect debris from the insect trap  14  by detaching the wave screen  10 , pouring the insect debris from the trap cup  12  and replacing the trap cup  12 .  
         [0042]     While specific embodiments of the wave-shaped insect trap of the present invention have been shown and described for an insect trap, these embodiments describe the best mode of practicing the invention as it is now known. It is not intended to limit the invention, and a number of other possible frame or holder designed are contemplated. It will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.