Abstract:
An inlet filter includes a cap and a body that are securely connectable to one another. Once connected, these elements form the structural backbone of the filter. Disposed between the cap and body is a transparent cover that allows one to view a filtering screen located within. Thus, the inlet filter serves to remove particulate matter from a supply of water prior to supplying it to a high pressure sprayer or similar device. As the filtering screen becomes clogged, its status can be visually determined. Thus a clear and readily apparent indication is presented as to when the filter needs to be cleaned or replaced.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to filters. More specifically, the present invention is an inlet filter for a high pressure sprayer. 
     2. Description of the Related Art 
     There are a wide variety of mechanical devices that require a constant fluid input from a bulk supply. For example, high pressure sprayers are used for many applications. Such sprayers take water (usually) from a low pressure source and pass it through a pump, where a dramatic increase in fluid pressure is achieved. Subsequently, the pressurized water is controllably and selectively dispensed from an appropriate wand or nozzle. 
     The various components of these sprayers are generally manufactured to high tolerances from a durable material. In use, various valves and connectors are actuated to initiate and then cease the flow of high pressure fluid. This cycling in and of itself produces significant stress on the components of the sprayer and the pump. 
     Two competing interests exist when designing high pressure sprayers. The components must be strong enough to endure the stresses imposed during use. In addition, the components must be manufactured to interact with one another with a great degree of precision. Often these interacting components are fairly small and intricate. Even the larger components will only have a small margin of acceptable error. 
     Many manufactures have successfully designed sprayers that will work properly under such conditions. The complicating factor during the actual use of these sprayers is that the water supply is normally unfiltered. For example, in many home and light commercial applications, a garden hose is connected to the inlet of the sprayer. Thus, the water entering the sprayer can be contaminated with varying amounts of dirt or other particles. These contaminates can either be introduced through contamination of the garden hose during other applications, or they are introduced to the water at its source (or through the interconnecting piping) and carried throughout. In any event, a fair amount of contaminates are expected to be introduced to the sprayer and the pump from the water. 
     As discussed above, with the high levels of pressure involved, the movement of the components, and the required degree of precision in their interaction, it should be readily apparent why the introduction of particulate matter into this system could be destructive. At a minimum, debris may simply clog a nozzle, a port or other orifice. While not necessarily damaging, the system will have to be cleaned, requiring a certain amount of disassembly and down time. More seriously, debris may enter and damage various components in the pump or unloader. Once damaged, these parts will have to be replaced and could be very costly. More specifically, debris in the system can hold open regulation valves in the unloader or regulator or valves within the pump itself. This can cause the system to stop working altogether or it could simply cause it to perform poorly. In addition, such debris will cause these valves and other components to wear prematurely. 
     In order to avoid the damage caused by contaminates, it has become standard practice to place a filtering device on the inlet side of the pump. Water being introduced into the system is first filtered, removing any particulate material that could otherwise cause damage to the various components. This is, of course, an elegantly simple solution to the above problem. The one drawback is that any given filter will have a limited useful life span. As the filter becomes clogged with particulate matter, it will reduce the volume of water passing through it. If the volume per unit of time becomes too low, it will adversely affect the performance of the pressure sprayer. 
     To overcome this problem, the filtering element must be periodically inspected and replaced. Generally, the filtering element will be occluded from view; hence, the entire filter must be detached and taken apart to expose the filtering element. Since variations in the quality of the water will occur as well as variations in the frequency of use, it becomes difficult to predict or estimate when the filter element should be checked and/or replaced. Many times the filter is not inspected until a loss in performance is seen, as some operators do not realize the importance of proper filtration. By this time, damage may have occurred to the pump due to cavitation caused by the lack of adequate flow into the pump. Thus, fairly frequent and time consuming inspections must be performed. 
     Therefore, there exist a need to provide an inlet filter for a pressure sprayer that can provide a readily apparent indication that the filtering element is in need of replacing, without requiring detachment and disassembly of the filter for inspection. 
     SUMMARY OF THE INVENTION 
     The present invention provides a multi-piece inlet filter having a clear, non-load bearing cover. A screen is used as a filtering element and is visible through the clear cover. The durability of the cover is maintained because the cover is a non-load-bearing element. In order to provide an integrated cover that is non-load bearing, the various internal components must provide structural integrity for the whole filter. 
     In a preferred embodiment, the filter includes a body and a cap, securely inter-connectable to one another. The body includes a threaded portion that is coupleable to the inlet of a sprayer. At an opposite end, the body has a female coupling adapted to receive a male coupling provided on the cap. One or more inlet ports are located on the female coupling and provide access to a fluid passageway within the body. The fluid passageway terminates in an outlet passageway that is ultimately coupled to the inlet of the sprayer. Similarly, the male coupling of the cap is provided with one or more outlet ports that provide access to a fluid passageway within the cap. This fluid passageway runs through a fitting on the cap. The fitting is adapted to receive various common types of water supply fixtures, such as a garden hose. 
     The screen or filter is slid over the female coupling of the body and entirely covers the various inlet ports. Subsequently, the male coupling of the cap is engaged with the female coupling of the body. The clear cover is disposed between the body and the cap, and is effectively “sandwiched” between them. Appropriate seals are provided so that a fluid tight seal is formed between the cover and the cap and body, respectively. While a fluid tight seal is provided, the cover is a non-load bearing element. As defined herein, non-load bearing means that the cover is not relied on to couple the cap to the body and that the actual coupling of the cap to the body is completely independent of the cover. The cover will be required to withstand any pressure generated from the flow of fluid though it and must do so in a fluid tight manner. 
     Once properly assembled, a complete fluid passageway is formed. Water is directed into an inlet passageway through the fitting of the cap from a common water supply, such as a garden hose. Water passes through the cap and out of the outlet ports disposed on the male coupling of the cap. At this point, the water is contained within the cover due to the fluid tight seal generated between it and the cap and body. The water is then forced to travel through the screen and then through the inlet ports located on the female coupling of the body. Subsequently, the water passes unencumbered through the body and out of the outlet passageway where it is introduced into the pressure sprayer. 
     The screen is configured so that the openings in the mesh are smaller than particles that may adversely affect the performance of the sprayer. Thus, as fluid flows from the cap to the body, particulate matter larger than a predetermined size will be precluded from passing through the screen and into the pressure sprayer. Through continued use, the screen will eventually begin to clog. This will be readily apparent by directly viewing the screen through the transparent cover. Once it is determined that the screen needs to be cleaned or replaced, the cap is unscrewed from the body. The screen is then slid off and either cleaned or replaced. The new or cleaned screen is then slid back over the coupling of the body and the inlet filter is reassembled. The filter body does not have to be removed from the pump inlet to clean or replace the screen. In this manner, the inlet filter is cleaned when the filtering element visually shows the need. 
     In an alternative embodiment, a bypass inlet port has been added to the body, between the body inlet ports and the outlet passageway. In certain pressure sprayers, there will be various bypass functions that direct filtered water somewhere other than the nozzle or wand. For example, the unloader may include a bypass valve. This water must be routed back to the pump inlet. In order to be more efficient, this water can be reintroduced into the sprayer through the inlet filter. Opposite the bypass port a monitoring device such as a pump thermal protector (PTP) can be installed or other inlet component. This simplifies replacement and cleaning of the filter screen as the filter body containing the bypass port and PTP does not have to be disturbed, as it can remain attached to the pump inlet during cleaning. 
     It is an object of the present invention to provide an inlet filter having a transparent cover. 
     It is another object of the present invention to provide an inlet filter having a non-load bearing transparent cover. 
     It is yet another object of the present invention to provide an inlet filter having a filtering element viewable from the exterior of the filter. 
     It is still yet a further object of the present invention to provide an inlet filter having a cap and a body that are inter-connectable and are the load bearing elements of the filter, while a transparent cap is fluidly sealed between the cap and the body. 
     It is still yet another object of the present invention to provide a filter with a sealed cover wherein the sealing occurs through the use of diametrical seals (i.e. O-Rings) located on an inside diameter. 
     It is yet still another object of the present invention to provide a filter with a sealed cover wherein the sealing occurs through the use of compressible gasket material located at the ends of the cover. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side planar view of an assembled inlet filter according to the teachings of the present invention. 
     FIG. 2 is a side sectional view of an assembled inlet filter according to the teachings of the present invention. 
     FIG. 3 is a sectional view of the assembled inlet filter illustrated in FIG. 1, and taken through sectional line  3 — 3 . 
     FIG. 4 is an exploded perspective view of the components of the inlet filter of the present invention, wherein alternative bodies, A and B are each illustrated. 
     FIG. 5 is a side sectional view of body B, illustrated in FIG.  4 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to FIG. 4, a preferred embodiment of an inlet filter according to the teachings of the present invention is shown and generally referred to as  10 . Inlet filter  10  includes a body  12  having a female coupling  14  at one end. Female coupling  14  is an elongated cylindrical member having a fluid passageway  15  extending at least partially therethrough and includes at least a partially threaded interior  17 . Fluid passageway  15  is shown extending through the whole of body  12 . 
     Disposed about the circumference of female coupling  14  is a plurality of circular body inlet ports  18 . Inlet ports  18  fluidly couple the exterior of female coupling  14  to fluid passageway  15 . While this embodiment presents four circular inlet ports  18 , it is to be understood that any number of ports may be utilized and the ports may be of various sizes and/or shapes. It is desirable to maximize the volume of fluid flow per unit of time through the inlet ports  18  while minimizing any structural degradation that might occur by proving too large or too many inlet ports. At the opposite end of body  12  from female coupling  14 , an appropriate attachment mechanism is provided to couple inlet filter  10  to the desired pressure sprayer or a similar fluid using device. In this embodiment, a threaded attachment member  16  is provided to accomplish this. Threaded attachment member  16  can be screwed into an inlet of the desired device. Fluid passageway  15  extends through threaded attachment member  16  and will be connected with an appropriate passageway within the device via outlet passageway  20 . 
     A cap  22  is provided and has a fluid passageway  23  extending partially therethrough. Fluid passageway  23  begins with inlet passageway  30  located on the interior of fitting  26 . Fitting  26  is configured to receive various common fluid supply connectors, such as the threaded connector of a garden hose. As shown, fitting  26  is threaded to securely receive the connector of a garden hose and includes seal  32  to form fluid tight connection. It is to be understood that fitting  26  can be modified to receive various fluid supply couplings. Opposite from fitting  26 , a male coupling  24  is provided. Male coupling  24  is a generally cylindrical member having a plurality of cap outlet ports  28  fluidly connected with fluid passageway  23 . As illustrated, male coupling terminates in an externally threaded cylindrical section  42 . Male coupling  24  also includes terminus  29 , which effectively seals or terminates fluid passageway  23 . 
     Cap  22  is coupleable to body  12 . More precisely, male coupling  24  is intended to be securely connected to female coupling  14 . As illustrated, these components are provided with complimentary threaded sections so that cap  22  can be screwed into body  12 . Various other types of interconnections between cap  22  and body  12  are possible. For example, various quick connects or snap-locks could be utilized. As explained in more detail below, a screen  36  is provided to filter water passing through inlet filter  10 . In this embodiment, screen  36  can be replaced or cleaned simply by unscrewing cap  22  from body  12 . It is also possible to manufacture inlet filter  10  from less expensive components so that the entire inlet filter  10  can be replaced, rather than just replacing screen  36 . Should this be the case, male coupling  24  and female coupling  14  could be connected through various frictional clamping mechanisms, that are not intended to be separated. 
     Body  12  and cap  22  can be made of various materials including plastics or metal. Most preferably, these components are formed from a durable metal such as brass. 
     As shown in FIG. 3, screen  36  is configured to snugly engage female coupling  14  and cover all of the body inlet ports  18 . Screen  36  can be fabricated from a wide variety of materials, including plastics or metals. Screen  36  acts as a filtering element and as such, includes a meshed element. The openings in the mesh are selected to be smaller that than smallest particulate element that is acceptably passed into the pressure sprayer or similar device. As such, the specifics of screen  36  will depend largely upon the machine inlet filter  10  will be used on. 
     A cylindrical cover  34  is also provided. Cover  34  has a hollow interior  35  that is spaced to accommodate portions of female coupling  14 , male coupling  24  and screen  36  while still leaving an area of unobstructed space around these elements. Most preferably, cover  34  is transparent allowing screen  36  to be viewed from the exterior of cover  34 . In some applications, it may be desirable to partially or wholly occlude cover  36 . Cover  36  can be fabricated from any appropriate material, so long as it is suitable to be in contact with the fluid passing though inlet filter  10 . Most preferably, cover  36  is fabricated from translucent plastic. Cover  34  is a non-load bearing member. As defined herein, cover  34  is non-load bearing when it is not used to couple cap  22  to body  12 . That is, cover  34  is disposed between cap  22  and body  12  in a fluid tight manner and must withstand force applied from the fluid passing through and any normal externally applied forces. However, cover  34  is not relied on to hold the various components of the filter together and can, therefore, be fabricated from lighter gauge materials. 
     FIG. 4 shows an exploded view of inlet filter  10 . To assemble inlet filter  10 , a first O-ring  38  is slid over female coupling  14  until it abuts a portion of body  12 . Subsequently, screen  36  is slid into position over inlet ports  18  on female coupling  14 . A second O-ring  38  is place over male coupling  24  on cap  22 . Then, cap  22  is screwed into body  12 , with cover  34  disposed between them. As male coupling  24  is tightly screwed into female coupling  14 , O-rings  38  form a fluid tight seal between cover  34  and each of body  12  and cap  22 . Once assembled, inlet filter  10  appears through cover  34  as shown in FIG.  1 . 
     Referring to FIGS. 1 and 2, the path taken by fluid passing through inlet filter  10  is most clearly shown. In use, fitting  26  is appropriately connected to a supply of water W 1 , such as a garden hose. Whatever the actual condition of the water being supplied, it is considered unfiltered as it has yet to pass through inlet filter  10 . As the fluid passes through inlet passageway  30  it is forced to enter fluid passageway  23  and then exit through one of the cap outlet ports  28 . At this point, the fluid is contained by cover  34  and flows through screen  36 , where it is filtered. The fluid then enters fluid passageway  15  (within body  12 ) through one of the body inlet ports  18 . The filtered fluid W 2  then exits inlet filter  10  through body outlet passageway  20 , and subsequently enters a high pressure sprayer or other similar device requiring a filtered fluid input. 
     As is most clearly illustrated by FIG. 2, the structural integrity of inlet filter  10  is derived exclusively from the interconnection of body  12  with cap  22 . Thus, cover  34  is simply held in place by cap  22  and body  12  in a fluid tight manner and is therefore not a load-bearing member. In other words, cover  34  is not used in any way to connect cap  22  to body  12 . Cover  34  does function to contain water, however, and must be able to withstand expected water pressures. Without cover  34 , inlet filter  10  would not function because fluid would simply be expelled from outlet ports  28 , however inlet filter  10  would remain structurally intact. In addition, any tension or forces generated and applied to either body  12  or cap  22  will simply be transmitted to the other load-bearing member and will not adversely affect cover  34 . In this manner, cover  34  can be fabricated from a lighter grade material such as plastic, without reducing the overall structural integrity of inlet filter  10 . 
     After a certain number of uses, screen  36  may become clogged with the particulate matter it is filtering from the fluid supply. The operator can visually determine the status of screen  36  by looking through the transparent cover  34 . When it is determined that screen  36  has become too encumbered, cap  22  is unthreaded from body  12 . Screen  36  can then be cleaned or a new screen can be obtained. In either case, a clean screen  36  is used and inlet filter  10  is reassembled. Alternatively, if cost effective and desired, inlet filter  10  can be replaced in its entirety. 
     Referring to FIGS. 4 and 5, an alternative embodiment is illustrated. Two substantially similar bodies  12  are shown and designated A and B. Body A is exactly as described above, while body B is the alternative embodiment. While both are illustrated, only one is used at any given time. Referring to body B, a bypass inlet port  40  is in fluid communication with fluid passageway  15 . Bypass inlet port  40  can be used to introduce fluid into the sprayer (or similar device) without filtering it. Though only one inlet port  40  is illustrated, it is to be understood that more could be included. One optimal configuration would be to have a second inlet port spread 180° from the illustrated inlet port  40 . For example, an unloader valve in some high pressure sprayers will have a bypass valve, that redirects water under various conditions. This bypassed water has already been filtered and reintroducing it into the system through bypass inlet port  40  provides a convenient way to recycle it. The additional ports can also be used for system monitoring devices such as a pump thermal protector. Alternatively, additional inlet ports could be included on cap  22 , if it is desired to filter the fluid. This would allow for multiple inputs. In addition, this would allow for the introduction of different fluids into the system. That is, more than one type of fluid could be introduced through inlet filter  10 , at the same time. The additional fluids could either be filtered or unfiltered, depending upon the location of that additional inlet port. 
     Though inlet filter  10  has been described with reference to two specific embodiments, it is to be understood the present invention includes various modifications, which are still considered to be within the scope and spirit of the present invention. For example, cap  22  may be coupled to body  12  through various other mechanisms (some of which are described above), rather than using mating threads. The type of connection is not as important as assuring that cap  22  and body  12  act as the load bearing elements of filter  10 , when assembled. Additionally, various other types of filtering elements could be used instead of screen  36  (or positioned differently), so long as the fluid is filtered prior to exiting inlet filter  10 . 
     Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be understood that other variations are contemplated as being within the scope of the present invention. Accordingly, the present invention is not limited in the particular embodiments which have been described in detail therein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention.