Abstract:
A fluid reservoir assembly, for containing a fluid such as a lubricant is disclosed with a first end plate, a body and a second end plate. The body is preferably formed from plastic or glass. The end plates are composed of a molded plastic resin and are sealingly fastened to the body with an adhesive. The reservoir assembly has an inlet and outlet. Depending upon the configuration of the end plates and body, reservoirs of various sizes, capacities and cross-sectional shapes (e.g. circular, rectangular, etc.) can be fabricated without the need for dedicated molds and specialized tooling.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to reservoirs used for holding and dispensing fluids, such as lubricants. Reservoirs of various capacities are used to contain and dispense lubricants for lubricating machine tools, machinery, pneumatic tools, conveyors and the like. The size of the reservoir is typically determined by its application or the amount of fluid that is required to be dispensed over a predetermined time period. Reservoirs typically have an inlet for filling the reservoir with fluid and an outlet through which the fluid is dispensed. 
         [0002]    At present there are a variety of reservoirs for containing and dispensing fluids, such as lubricants. One common prior art reservoir uses a cylindrical or rectangular container with a screw on top cover. Another uses a cylindrical or rectangular container with a screw on bottom cover. In both instances, the containers may be made from glass or plastic. In the case of plastic containers, they are typically formed by either rotational or blow molding techniques. The contents of these reservoirs may become contaminated if an operator fails to reinstall the cover after filling the reservoir. They also do not allow a manufacturer to inexpensively produce many varying capacities because each size of reservoir container must be formed or molded from a specifically sized and dedicated mold. Furthermore the manufacturing process, whether made from glass or plastic, requires that threads be integrally molded into the container body as well as the removable cover so that the two will threadingly mate and seal. 
         [0003]    Another typical prior art reservoir utilizes a top end plate, a bottom end plate, a cylindrical body and a centrally located tie rod to secure the end plates to each end of the cylindrical body. A gasket is typically placed at the junction of the body and each end plate to provide a fluid-tight seal. In the prior art, the end plates are commonly made from stamped sheet steel or cast and machined aluminum. The tie rod passes through an opening in the top end plate, through the body and through a similar opening in the bottom end plate. Fittings or fasteners are threaded onto the ends of the tie rod on the outer surfaces of the end plates so that a fluid tight seal is formed between each end plate, gasket and body. The tie rod that passes through the assembled reservoir alters the capacity of the reservoir and obstructs full visibility there through. This reservoir configuration also does not provide a contamination-proof assembly because the tie rod fittings and/or fasteners can loosen during shipping or over a period of time which is likely to result in reservoir leakage. This common prior art design also has multiple points where elastomeric seals are required to prevent leaks. Over time, seals can also fail thus leading to leaks. As described, this design requires numerous parts and components. Additionally, the variation of reservoir heights is limited to the length of tie rods available. 
         [0004]    Prior art reservoirs that require a multitude of parts for assembly have other shortcomings. Some of these parts limit the variety of reservoir capacities, and also add weight, cost, and time to their manufacturing processes. Reducing any extraneous parts and/or capacity limiting parameters would be beneficial and considered an improvement in the art. It is desirable to have a reservoir whose capacity is known and whose interior visibility is not obstructed. It is desirable to have a fluid reservoir that is not subject to fluid contamination and leaks. It is also desirable to have a fluid reservoir that is lightweight yet durable during shipping as well as in use. It is furthermore desirable to have a fluid reservoir that is easy to install, is rotationally adjustable after installation, has a universal outlet fitting and is easy to fill with fluid. 
       SUMMARY OF THE INVENTION 
       [0005]    In one respect, a reservoir for housing fluid is provided. The reservoir includes a body which forms a cavity when enclosed by two end plates. The body has opposed open ends and a wall that defines an interior. For example, the body may be cylindrical in shape or cubical in shape. The body is formed from either plastic or glass. For example, the body may be fabricated from an acrylic plastic, glass, PYREX® brand glass or another suitable material. The end plates that enclose the open ends are molded from plastic, such as polycarbonate, polypropylene or similar resins. In a preferred embodiment, the end plates are substantially identical to one another. The molded end plates are secured to the open ends of the body with an adhesive. The adhesive forms a fluid-tight seal between the mating body and end plate. Thus each end plate is sealingly attached to the body. Preferably, a two-part adhesive is utilized. The adhesive may alternatively be a one-part adhesive or cured with UV light during the assembly process. 
         [0006]    In one possible configuration, one of the end plates contains an inlet and the other end plate contains an outlet. Other possible configurations may include a fluid filter which filters out impurities in the liquid as it exits the reservoir and/or a low level switch which can be used to actuate warning devices or shut off a machine receiving the fluid or lubricant to prevent machine damage. 
         [0007]    Depending upon the configuration of the end plates and the body, reservoirs of various sizes and capacities can be fabricated without the need for an expensive mold and specialized tooling. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a perspective view of a first embodiment of the reservoir. 
           [0009]      FIG. 2  is an exploded view of a first embodiment of the reservoir. 
           [0010]      FIG. 3  is a front sectional view of a first embodiment of the reservoir along line  3 - 3  of  FIG. 1 . 
           [0011]      FIG. 4  is a front sectional view of a first embodiment of the reservoir with a filter. 
           [0012]      FIG. 5  is a front sectional view of a first embodiment of the reservoir with a low level switch. 
           [0013]      FIG. 6  is a front sectional view of a first embodiment of the reservoir with a filter and a low level switch. 
           [0014]      FIG. 7  is a perspective view of a second embodiment of the reservoir. 
           [0015]      FIG. 8  is a front sectional view of a second embodiment of the reservoir along line  8 - 8  of  FIG. 7 . 
           [0016]      FIG. 9  is a perspective view of a second embodiment of the reservoir. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0017]    Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
         [0018]    Referring now to  FIG. 1 , the general arrangement of one representative embodiment of a reservoir  10  is shown. The arrangement includes a cylindrical body  20  situated between a first molded end plate  12  and a second molded end plate  22 . With the exception of openings for an inlet, outlet and/or level switch and/or indicia formed in or on the end plates  12  and  22 , the first end plate  12  and second end plate  22  are substantially identical. The cylindrical body  20  may be fabricated from plastic, such as acrylic or from glass, such as PYREX® brand glass or from any other suitable material. Now referring to  FIG. 2 , the body  20  has at least one wall  27  that defines a cavity having open first and second ends  13  and  17 , respectively. The wall  27  further has opposite wall edges  19  and  21 . While shown to be cylindrical in the Figures, the body  20  can have any geometric cross section, shape or configuration. By way of example only, the body may be cubical as opposed to cylindrical as shown. The first end plate  12  has an inlet assembly  15  secured thereto in a fluid tight configuration at a central portion  42  of the end plate  12  as shown in  FIGS. 1 and 2 . The second end plate  22  has an outlet member  24  secured thereto, preferably in an opening  38  formed in a central portion of the end plate  22 . The openings  38  and  40  for the respective inlets and outlet may be formed when the end plates  12 ,  22  are molded (as shown in the Figures) or may be formed, for example by machining after the molding process is complete. End plates  12  and  22  are molded from plastic resin such as polycarbonate. Alternatively, the resin may be polyurethane, polypropylene, or any other material conducive to the application of the reservoir  10 . Preferably, the material selected for end plates  12  and  22  is chemically resistant. Also depending upon the application, the plastic resin may contain a predetermined amount of reground material. 
         [0019]    As best shown in the exploded view of  FIG. 2 , the inlet assembly  15  includes an inlet cap or lid  14  connected to an inlet cap body  18  by an inlet cap tether or pin  16 . The inlet assembly  15  allows for the inlet cap or lid  14  to be pivoted or picked up and rotated approximately 180 degrees out of the way about the inlet cap body  18  for filling of the reservoir  10  with a fluid (not shown). This configuration exposes the full opening for filling and does not require the operator to hold the cap  14  during filling. The inlet cap  14  furthermore remains attached to the inlet cap body  18  by the inlet cap tether or pin  16 . In addition, the fill cap or lid  14  provides venting of the reservoir  10 . It is to be understood that this is just an example of one type of suitable inlet assembly  15 . Other types of inlet assemblies that allow for ease of filling and venting may be used as well. Preferably, inlet assembly  15  is affixed to end plate  12  at its central portion  42  in a fluid tight configuration. 
         [0020]    Referring again to  FIG. 2 , the first end plate  12  and second end plate  22  are affixed and sealed to the cylindrical body  20  in a fluid tight configuration with an adhesive  32 . After the adhesive is applied to either the first wall edge  19  or groove  36  or to both (see  FIG. 3 ), the first end  13  of the cylindrical body  20  is placed inside the first end plate circumferential groove  36  and the adhesive  32  secures and seals this juncture. Similarly, the second edge  21  of the cylindrical body  20  is placed in the second end plate circumferential groove  34  which is similarly secured and sealed by the adhesive  32  to the cylindrical body  20 . The fluid tight and sealed configuration of the first end plate groove  36 , in which the first end  19  of the cylindrical body  20  seals and the second end plate groove  32  are best shown in the sectional view of  FIG. 3 . A two-part adhesive, such as Resinlab AR4305HP acrylic adhesive is preferable. After the two-part adhesive is applied, the reservoir may be placed in a fixture or jig to hold the end plates  12  and  22  securely to the cylindrical body  20  until the adhesive  32  has appropriately cured. This takes approximately 10 to 15 minutes. A one-part adhesive may also be used. For use on polypropylene end plates  12  and/or  22 , Scotch Weld DP  8005  adhesive is preferred. 
         [0021]    Additionally, the adhesive  32  may be an adhesive that is curable by ultraviolet light. This aids in the manufacturing process. The benefits of using this adhesive are many. It allows for proper positioning of the parts before curing, and once the parts are known to be in place and the UV light is applied, the curing time is minimal. This promotes both consistency and efficiency, which will eliminate waste and reduce cost. Other one-part and two-part adhesives may also be used because they, too, provide a consistent adhesive application. Any adhesives, however, may be substituted with other types of sealing compounds depending on the requirements, contents and/or specifications of the reservoir application. 
         [0022]    Furthermore, the use of adhesive  32  to attach the end plates  12  and  22  allows for the production of reservoirs  10  of various sizes or capacities without having to construct a multitude of different parts or have a multitude of different molds. The variety of reservoir capacities is almost limitless because any length L (see  FIG. 2 ) of body height, within reason, may be chosen. In the preferred embodiment the cylindrical body  20  is acrylic; however, glass or another suitable material may be used. 
         [0023]    Moreover, the end plates  12  and  22  may be modified or customized for different applications. For instance, notification may be important for quickly identifying the type of fluid being housed within a reservoir  10  or the capacity of a reservoir  10 . If desired, the end plates  12  and  22  may be engraved, colored, or otherwise designated for whatever the application requires. This can be done at the time the end plates  12  and  22  are molded or afterward. For example, one or both end plates  12  and  22  may be molded in a predetermined color. Alternatively or additionally, indicia may be formed in or applied to at least one of the end plates  12  and  22  during the molding process or afterward by engraving on the end plate  12  and/or  22 . In our preferred embodiment, the end plates  12  and  22  are molded of a chemical resistant resin. 
         [0024]    Additionally, in the present embodiment 10, the cylindrical body  20  and the affixed end plates  12  and  22  may be capable of rotating relative to the orientation of the outlet member  24 . Outlet member  24  includes a threaded portion  27  and it will appreciated that once threaded portion  27  is tightened into a mating fitting (not shown), it may be desirable to rotationally adjust the reservoir  10 . This may be desired where indicia or other markings (not shown) on the cylindrical body  20  or the end plates  12  and  22  is difficult to see after the reservoir  10  is installed on a machine, tool or air line. This may also be desired to obtain the correct orientation of the fill cap assembly  15 , especially the “open” or filling position of fill cap or lid  14  relative to outlet member  24 . Referring again to  FIGS. 2 and 3 , this may be achieved by inserting the first end  25  of the outlet member  24  into the second end plate  22  opening  38  and placing an internal tooth lock washer  30 , or similar device, over the first end  25  providing for a secure connection but allowing for rotation. It is important to note that no threaded fastener is required. Fluid is prevented from leaking out of the second end plate opening  38  by a seal such as an o-ring  26  located on the seal groove  28  of the outlet member  24 . As will be apparent to those skilled in the art, there are other configurations that may be employed for attaching outlet member  24  to end plate  22 ; those configurations fall within the scope of the present invention as well. 
         [0025]    As best seen in  FIGS. 1 and 3 , the outlet fitting  24  is preferably attached to end plate  22  such that minimal residual fluid remains in reservoir  10  when the reservoir is emptied through the opening  38 . Furthermore, it will be appreciated that the outlet fitting  24  can accept various sized threaded fittings as required for any specific application. 
         [0026]      FIG. 4  shows an embodiment of the reservoir  10  with a filter  50  as part of, or affixed to, the outlet member  24 . This filter  50  prohibits unwanted particles or impurities (not shown) in the fluid within the reservoir  10  from exiting the reservoir. 
         [0027]      FIG. 5  shows an embodiment of the reservoir  10  with a low level switch  54 . The low level switch  54  may be used to indicate a low fluid level in the reservoir  10 . In the embodiment shown, an alternate lower end plate  52  with low level switch adaptability is used in order to accommodate the low level switch  54 . To accommodate a low level switch  54 , a suitable second opening  56  is formed in the molded end plate  52 . Opening  56  may be molded or formed (machined) after the molding process is complete. The switch  54  may be retained by any conventional means, including the use of an internal lock tooth washer as described above. In addition, the low level switch  54  may be rotated in the end plate  52  for proper orientation of a conduit fitting. 
         [0028]      FIG. 6  shows an embodiment of the reservoir  10  with both a filter  50  and a low level switch  54 . This embodiment is a combination of the embodiments shown in  FIGS. 4 and 5 . 
         [0029]      FIGS. 7 and 8  show an embodiment of the reservoir,  60 , including an alternate outlet assembly  62  including a universal outlet fitting  64 . Universal outlet fitting  64  has a standard sized threaded outlet diameter  70  that can be coupled to a multitude of additional fittings such as couplers, nipples, pipes, conduits, site gages, manifolds, etc. As in the previously described embodiment 10, the cylindrical body  20  and the affixed end plates  12  and  22  in conjunction with universal fitting  64  may be capable of rotating relative to the orientation of the outlet assembly  62 . This may be desired where indicia or other markings (not shown) on the cylindrical body  20  or the end plates  12  and  22  is difficult to see after the reservoir  60  is installed on a machine, tool or air line. This may also be desired to obtain the correct orientation of the fill cap assembly  15 , especially the “open” or filling position of fill cap or lid  14  relative to outlet member  24 . Referring to  FIGS. 7 and 8 , this may be achieved by inserting the first end  65  of the universal outlet fitting  64  into the second end plate  22  opening  38  and placing an internal tooth lock washer  30 , or similar device, over the first end  65  providing for a secure connection but allowing for rotation. Again, it is important to note that no threaded fastener is required. Fluid is prevented from leaking out of the second end plate opening  38  by a seal such as an o-ring  66  located on the seal groove  68  of the universal outlet fitting  64 . The end user of the reservoir  10  can interchange any required fitting to mate with the universal outlet fitting  64 . Universal outlet fitting  64  has a standard internally threaded opening  70 . A second fitting, such as fitting  72 , may be threaded into opening  70  as shown in  FIG. 8 . While the external threads and diameter  74  on fitting  72  match those of internal threads and diameter  70  of universal outlet fitting  64 , it will be appreciated that external threads and diameter  76  may be the same or be any different size as required by the reservoir  60  application. As such, all reservoirs  60  can be fabricated with universal outlet fitting  64  and a fitting  72  may be installed after fabrication by either the manufacturer or the customer (end user) as required for the specific application. A fourth feature or benefit of the universal outlet fitting  64  is applicable to reservoirs  10  with level switches, such as the level switches  54  shown in  FIGS. 5 and 6 . The universal outlet fitting  64  allows different orientations of reservoir  10  relative to the location and/or position of the level switch  54 . 
         [0030]    One of the universal outlet fitting features is illustrated in  FIG. 9  where a dual flow control valve with sights and vents  80  is shown connected to universal outlet fitting  64 . It is to be appreciated that any number of other fittings and conduit configurations can be attached or coupled to universal outlet fitting  64 . As will again be apparent to those skilled in the art, there are also other configurations that may be employed for attaching universal outlet fitting  64  to end plate  22 ; all of these configurations fall within the scope of the present invention as well. 
         [0031]    As shown in  FIGS. 7 ,  8  and  9 , the universal outlet fitting  64 , including first (unthreaded) end  65  is preferably attached to end plate  22  such that minimal residual fluid remains in reservoir  10  when the reservoir is emptied through the opening  38 . 
         [0032]    The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While certain embodiments have been described, the details may be changed without departing from the invention, which is defined by the claims. cm We claim: