Abstract:
A portable hydraulic fluid handler cart capable of transporting liquid storage containers and providing filtered fluid transfer. Quick-disconnect couplers at the cart and system adapters, along with replaceable filter cartridges, maintain fluid integrity at the system and serviced equipment. An electric motor, transfer pump, retractable extension cord and power control switch mount to the cart. Forks, rails and an adjustable clamp contain a liquid drum to the cart. A pair of handles and four wheels facilitate gripping, tipping and transport of drum containers. A kickstand stabilizes the cart when used alone. The filter media at the cart and adapters is selected to simultaneously filter liquid-borne and airborne particles and water from the fluid.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to hydraulic fluid handling systems and, in particular, to a portable fluid transfer cart capable of transporting a supply of hydraulic fluid and having vented, quick-disconnect transfer conduits for servicing bulk reservoirs and maintaining fluid integrity. 
     Numerous equipment problems can develop from contaminants present in hydraulic fluids. The problems can range from faulty equipment operation to potential destruction of costly valves, pumps and other components. Contaminants can consist of dirt particles, metal particles and shavings, sludge, and water, to name some of the typical types of contaminants that are encountered in industrial settings. 
     Contaminants can enter a hydraulic system and collect in the fluid over time with equipment wear or faulty seals. Contaminants can also be added into a system during periodic refilling and maintenance operations performed on the equipment. The contaminants can be added with the normal coupling and uncoupling of the transfer conduits, that is the placement of contaminated, dirt laden transfer tubes into the fluid or the attachment of dirty, threaded couplers to the bungholes of the reservoir. The contaminants can arise from improperly cleaned drum containers from which the liquids are transferred. Harmful dust particles can also be injected into the system at the vented breather mounted to the equipment reservoir. 
     Depending upon the type of equipment and cost, permanent filter systems can be included at the equipment to daily maintain and monitor the quality of fluids flowing through the hydraulic lines. Additionally or in the alternative, the fluids can be periodically cleaned and serviced by maintenance personnel with the aid of a portable cart that supports a transfer pump, filters and transfer conduits. A typical cart consists of a two-wheel dolly that is outfitted with a fluid catch pan, a motor driven transfer pump, one or more replaceable filters, filter manifolds and interconnecting piping. Flexible hoses, threaded couplers and tubular wands appropriately extend from the cart and mount to threaded bung holes commonly found at the equipment&#39;s fluid reservoir. A dolly, forklift or other handler is separately required to transport bulk containers (e.g. 30 to 55 gallon drums) that contain replacement fluid. 
     The carts can be operated in a closed-loop cycle with the equipment reservoir to filter the equipment fluid either when the equipment is shutdown or as it is being circulated through the equipment. The cart can separately circulate and clean fluids received in the bulk shipping containers, prior to adding the fluids to equipment undergoing maintenance. The cart can also be used to transfer dirty fluids from the equipment reservoir to a waste container. 
     As noted and instead of reducing contaminants, contaminants can be added each time the couplers, wands and hoses of the maintenance cart, which are exposed to the relatively dirty surrounding environment between use, are mounted to the equipment. The relatively large mesh size (i.e. 30 to 100 mesh) breathers used at typical equipment reservoirs can also inject dust into the fluids. 
     The fluid handler system of the present invention was developed to overcome the shortcomings of conventional fluid handlers. The handler provides a four-wheel cart that is capable of transporting drums of replacement fluid. The cart also supports a transfer pump and replaceable filter cartridges that simultaneously remove suspended particles and liquid contaminants. Quick-disconnect couplers and compatible vented and unvented container adapters prevent the introduction of contaminants during equipment servicing. The improved vented breather separately supports a replaceable filter cartridge that is capable of filtering micron size contaminants. 
     SUMMARY OF THE INVENTION 
     It is accordingly a primary object of the invention to provide hydraulic fluid handling equipment designed to prevent the addition of airborne and handler-borne contaminants into the treated fluid. 
     It is a further object of the invention to provide a multi-wheeled support cart capable of transporting a drum containing clean, replacement fluid and having a kick stand to stabilize the cart when used alone. 
     It is a further object of the invention to provide a support cart that is outfitted with a motor, transfer pump, filter manifold, replaceable cartridge filters containing the same or different types of filter or fluid treatment media, interconnecting conduits, extension cord and control circuitry. 
     It is a further object of the invention to provide reservoir couplers having quick-disconnect fittings. 
     It is a further object of the invention to provide vented breathers at the reservoir adapters that support replaceable filter cartridges. 
     Various of the foregoing objects, advantages and distinctions of the invention are obtained in one presently preferred multi-wheeled, cart handler. A tubular steel cart frame is outfitted with forks and an adjustable clamp that operate to grip a storage drum (e.g. 30 to 55 gallons). A pair of handles and four wheels are fitted to the frame to facilitate gripping and tipping a drum for stable transport on the four wheels. An electric motor and transfer pump are mounted to the cart along with a retractable extension cord and power control switch. A conduit couples the pump to a filter manifold and a pair of replaceable filter cartridges secured to the manifold. The filter media at the cartridges is selected to filter suspended particles of desired sizes and water or other liquid contaminants from the fluid during transfer. 
     Flexible hoses with quick-disconnect end couplers are fitted to the manifold and pump and interconnect with alternative quick-disconnect adapters that mount to the equipment reservoir being serviced. Threaded and flanged breather adapters are constructed to support replaceable cartridge filters that can filter airborne particles of a variety of sizes (e.g. &gt;3 microns). 
     Still other objects, advantages, distinctions and constructions of the invention will become more apparent from the following description with respect to the appended drawings. Similar components and assemblies are referred to in the various drawings with similar alphanumeric reference characters. The description should not be literally construed in limitation of the invention. Rather, the invention should be interpreted within the broad scope of the further appended claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective drawing of the cart handler as it appears when tipped for transport and supporting a drum containing a supply of clean or dirty, waste hydraulic fluid. 
     FIG. 2 is a perspective drawing showing a rear view of the cart with a kickstand lowered to stabilize the cart. 
     FIG. 3 is a hydraulic flow schematic of the handler system. 
     FIG. 4 is a perspective view of a threaded breather adapter with quick-disconnect coupler and down tube. 
     FIG. 5 is a perspective view of a breather adapter having a bolted flange and a quick-disconnect coupler and down tube. 
     FIG. 6 is a perspective view of an un-vented threaded adapter having a quick-disconnect coupler and down tube. 
     FIG. 7 is a cross section view through a vented breather adapter. 
    
    
     Similar structure at the drawings is referred to with the same reference numerals and/or characters. 
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1 and 2, perspective drawings are shown to the hydraulic fluid handler cart  2  of the invention. The cart  2  is outfitted with a hydraulic pump  4 , electric motor  6 , filter manifold  8  and replaceable filter cartridges  10  and  12 . The pump  4  is sized to accommodate a nominal flow rate in the range of 4 to 10 gallons per minute at a nominal operating pressure in the range of 100 to 200 pounds per square inch (psi). The motor  6  is selected to develop a nominal horsepower in the range of ¾ to 1½ hp, which is sufficient to drive the pump  4  at the rated flow. The size of the pump  4  and motor  6  can be varied as desired for particular applications. 
     A flexible conduit  14  couples the pump  4  to the filter manifold  8  with appropriate fittings  16 . Appropriate lengths of other flexible hoses  18  and  20  (e.g. 5 to 20 feet) are coupled to the filter manifold  8  and pump  6  and terminate in conventional quick-disconnect couplers  22 . The couplers  22  are machined to mate with quick-disconnect couplers  24  at the adapters  26  and  28 . The adapters  26  and  28  are normally mounted to a container of clean or dirty, waste fluid or a fluid reservoir at a piece of equipment that is being serviced. O&#39;ring seals and internal check valves (not shown) and spring biased, retractable collars  29  are provided to seal aligned flow bores  31  at the couplers  22  and  24 . The couplers  22  and  24  are available from a variety of manufacturers, such as Parker-Hannifin Corp., Dynaquip Corp. or others. 
     Although the adapters  26  and  28  are shown attached to a storage container  32  (e.g. 30 to 55 gallon barrel or drum) that contains fluid used during servicing of the equipment, the adapters  26  and  28  are typically secured to threaded bung holes  30  at the equipment&#39;s fluid reservoir. FIGS. 4,  5  and  6  depict alternative adapters  26 ,  27  and  28  that can be mounted to the equipment reservoir and/or barrel  32  and are discussed in greater detail below. The adapters  26  and  28  can be secured to the drum  32  as shown during a recirculation cycle or cleaning of the replacement fluid. The adapters can also be coupled to the equipment reservoir and the drum during a pump-down or transfer of dirty fluid to the drum  32 . 
     FIG. 3 depicts the liquid flow schematic for the handler cart  2 . Conventional visual monitors and bypass valves  34  arc provided at the filter manifold  8  to monitor fluid flow and confirm when the filter cartridges  10  and  12  should be replaced. The bypass valves prevent pressure buildup with a plugged filter and possible detachment of the hoses  18  and  20 . A separate pressure and thermal overload  36  is provided at the pump  4 . A thermal overload (not shown) is provided at the motor  6 . The liquid flow at the cart  2  can be varied as desired to accommodate other flow arrangements. For example, more or less filtering can be adapted to the cart  2  using conventional parts. 
     The replaceable filters  10  and  12  are selected to remove both suspended particles and liquids contained in the hydraulic fluid. Commercially available handlers are constructed to filter only one or the other contaminant and typically require disassembly of a canister that contains the filter media. The process is time consuming and messy and can result in contaminants from the workplace being added to the handler system. The filters  10  and  12 , in contrast, provide threaded, spin-off housings that contain a preferred media and are easily replaced without undue drainage or exposure of the handler flow path to contaminants. The type of filter media at the cart  2  can be changed by simply selecting a filter cartridge  10  or  12  containing an appropriate media. 
     Conveniently secured to the left side of the cart  2  is a retractable extension cord  38  and an on/off switch  40 . Maintenance personnel are thereby able to conveniently position the cart  2  relative to equipment being serviced. Power is also easily disconnected for personnel safety, if necessary. Other electrical and/or hydraulic controls can similarly be fitted to the cart  2  directly or with appropriate attachment plates. 
     The cart  2  is constructed of a tubular metal frame  42  that is adapted to permit maintenance personnel to conveniently transport a supply of hydraulic fluid to a maintenance site without the need for separate transport equipment. Previously, it has been necessary to have a separate drum cart or forklift available to transport replacement and/or waste fluids to and from the equipment. 
     A pair of primary wheels  44  (e.g.  8  to  12  inch diameter pneumatic or covered solid wheels) are secured to a primary axle  46  fitted to the bottom of the frame  42 . A pair of smaller, caster or dolly wheels  48  (e.g.  3  to  6  inch diameter) are secured to a cross piece  50  that projects from the back of the frame  42 . Ball bearing supports  52  allow the wheels  48  to rotate freely. The dolly wheels  48  are especially helpful to stabilize the cart  2  when a drum  32  is supported to the frame  42  and tipped back onto the wheels  44  and  48 . Handles  50  and  52  facilitate tipping, pulling and/or pushing the cart frame  42 . A kickstand  54  assists in supporting and preventing tipping of the cart  2  during storage or when used without a barrel  32 . 
     The barrel or drum  32  is supported to the frame  42  at a pair of forks or arms  56 , only one of which is shown. The forks  56  project from the front of the frame  42 . The forks  56  mate with a banded rim  58  at the bottom of the barrel  32 . A slide clamp  60  having a tang  62  and handle  64  grips an upper rim band  66  of the barrel  32 . The tang  62  is held to the band  66  upon being lowered along a longitudinal slide column  68 . Longitudinal rails  70  project from the sides of the cart  2  and support the sides of the barrel  32 . The forks  56 , clamp  60  and rails  70  safely contain the barrel  32  to the cart  2  and facilitate transport of the relatively heavy, liquid filled barrels  32 . 
     Returning attention to FIGS. 4,  5  and  6 , details are shown to the adapters  26 ,  27  and  28 . The vented, breather adapters  26  and  27  are essentially identical and are constructed to support a replaceable air filter cartridge  72 , reference FIG. 2. A typical cartridge  72  is selected to filter undesired airborne particles, for example as small as  3  microns. Airborne particles can enter the system with normal changing liquid levels and the necessity to vent the equipment storage reservoir. The filter cartridge  72  provides a threaded, spin-off housing similar to the filter cartridges  10  and/or  12 . 
     The adapter  26  includes a threaded end surface  74  that can mount to a  2 -inch bunghole of an equipment storage reservoir or barrel  32 . The adapter  27  differs in that it includes a flange  76  having a number of fastener holes  77  (e.g. 6 holes). The adapters  26 ,  27  and/or  28  can be permanently mounted to an equipment reservoir to facilitate periodic maintenance operations with the cart  2 . Vent ports  80  at the bottom of the end surface  74  and flange  76  are exposed to the interior of the fluid container or equipment reservoir. Channels within the adapters extend between the ports and a threaded bore  82  to which the filter  72  is mounted. 
     FIG. 7 shows a perspective view in partial cutaway to the adapter  27 . The adapter body  84  is machined from a metal blank to provide the threaded filter-receiving bore  82 . The vent ports  80  extend through the body  84  and intersect the bore  82 . Threaded ports  84  and  86  are separately machined to receive a quick-disconnect coupler  24  and a down tube  78 . An O&#39;ring  88  is supported between the fastener holes  77  and the port  86  to seal the bottom of the flange  76  when mounted to a drum  32  or equipment reservoir. 
     The quick-disconnect couplers  24  at the adapters  26 - 28  conveniently assure a drip-free coupling with the mating couplers  22  at the cart  2 , which was not previously possible with available adapters. The adapters  26  and  27  also support a replaceable breather media that filters smaller, micron size airborne contaminants than possible with conventional bayonet breathers. Conventional breathers typically contain a more porous media (e.g. 30 to 100 mesh). 
     A down tube or extension wand  78  is secured to each adapter  26 - 28 . The length and diameter of the down tubes  78  can be varied as desired. The down tubes  78  assure that the hydraulic fluids are pumped and released below the liquid surface to reduce the potential of adding airborne contaminants to the hydraulic fluid in the equipment. 
     While the invention has been described with respect to a presently preferred handler system and considered modifications or alternatives thereto, still other constrictions may be suggested to those skilled in the art. Selected ones of the foregoing features can also be included alone or arranged in different combinations in other handler systems. The foregoing description should therefore be construed to include all those embodiments within the spirit and scope of the following claims.