Abstract:
An improved fluid level verification apparatus which may be manufactured or otherwise fabricated as a kit and assembled at a remote location for use on liquid filled containers and configured to reduce inherent mechanical stresses on the inspection tube and resists leakage due to environmental, chemical, thermal or mechanical expansion cycles by using internal grooves and entrapped o-rings. The improved fluid level verification apparatus having at least one adjustable end to provide adjustable spacing between the fluid level verification apparatus inlet and outlet.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates generally to a fluid level verification apparatus which is operable to measure the amount of fluid present in an object of interest, such as a tank, machine, or other article of manufacture, and more specifically, to an apparatus which may be manufactured or otherwise fabricated as a kit and assembled at a remote location for use on particular machines or in manufacturing processes; and which minimizes the number of components required; and further to a fluid level verification apparatus which reduces mechanical, thermal and chemical stresses on the apparatus. 
         [0003]    2. Description of the Prior Art 
         [0004]    The prior art is sated with examples of fluid level verification apparatuses which provide a means for visually verifying or otherwise discovering the fluid levels in an object of interest, such as manufacturing machinery, fluid holding tanks, or other similar assemblies. For example, in certain industrial processes or in certain machines or other articles of manufacture, it is important that particular fluids, such as lubricants, coolants, hydraulic fluids, or other fluid components, be stored in tanks and periodically dispensed from such tanks. Prior art fluid verification devices have typically included a transparent tube or inspection window, which is connected in particular relation to the holding tank, and which provides a quick and convenient means by which an observer may visually verify the level of the fluid present. 
         [0005]    While the prior art devices have operated with success, they have been unsatisfactory in several respects. 
         [0006]    Gruett U.S. Pat. No. 5,323,653 provides a detailed background of the prior art and describes a fluid level verification apparatus that can be fabricated as a kit and assembled at a remote location. Gruett contemplates an inspection tube having an interior conduit dimensioned to create an interference fit with an o-ring used to hermetically seal the inspection tube to an end member. The Gruett apparatus requires a separate seal on the outer diameter of its glass inspection tube to complete a hermetic seal. 
         [0007]    Jackson U.S. Pat. No. 4,345,468 describes a double tube liquid site monitor which incorporates grooving and o-rings to isolate the inspection tube from the environment. However, the Jackson invention is complex and cumbersome, as it requires numerous parts to protect the inspection tube from the stresses caused by the environment. Moreover, the sealing function of the grooves are limited to the insert ends thus requiring the o-rings to rest against the internal and external surfaces of inspection tubes that have no such grooves and the problem of mechanical stress induced by the assembly of the inspection tubes to mating components is not contemplated. 
         [0008]    Evans U.S. Pat. No. 4,050,305 describes an external shield bracket for a fluid flowmeter. The fluid of interest flows through a precision glass tube. An operator is protected from accidental explosion of the inspection tube due to fluid pressure by a protective transparent cover mounted on a u-shaped channel bracket. The Evans invention uses many parts, but fails to protect the inspection tube from the environment. Said transparent cover and mounting bracket do not form a hermetic closure for the inspection tube contained therein. 
         [0009]    Gruett U.S. Pat. No. 3,886,796 describes a liquid level gauge with a rigid transparent plastic inspection tube with o-rings seated in grooves located in the end members. The Gruett invention induces mechanical stress on the inspection tube because Gruett did not contemplate o-ring grooves on the exterior or interior portions of the inspection tube. Further, because the ends of the inspection tube are restricted and nested in end members, stresses related to thermal, environmental and chemical expansion cycles are exasperated. 
         [0010]    Lyden U.S. Pat. No. 3,540,276 describes a fluid level gauge. The Lyden invention uses an o-ring seal nested in an end member, communicating with the adjacent end of a site tube. Fluid leaks are minimized by placing the glass site tube in compression with the o-ring seal nested in the respective end member. The glass site tube is required because the Lyden invention requires compressive force on the tube. Thus, the design creates inherent mechanical stress and without utilizing the glass site tube adopts poorly to thermal, environmental and chemical expansion cycles and therefore would be susceptible to leakage. 
         [0011]    Wech U.S. Pat. No. 6,532,815 describes a fluid level gauge. The Wech invention discloses a groove in an inspection tube and a groove in the nipple of a block in which an o-ring is placed. The design provides for ease of assembly and reduces the effects of inherent environmental stress on the apparatus. However, when installing the device, the mounting positions must be exact otherwise the o-ring will not sit properly in the two grooves. This makes installation more complicated and reliant on perfect placement. Incorrect installation would not only negatively impact the functionality of the device, but could also severely damage the tank on which it is to be installed. 
         [0012]    In addition to the foregoing, many of the prior art devices are cumbersome and otherwise complex in their overall design, thereby increasing the cost to manufacture, decreasing the reliability and making them difficult to maintain. Further, the prior art is replete with designs that inadequately address the often conflicting requirements of resisting fluid leaks and protecting the inspection tube from mechanical, environmental, thermal and chemical stresses. 
       SUMMARY OF THE INVENTION 
       [0013]    Therefore, it is an object of the present invention to provide an improved fluid level verification apparatus. 
         [0014]    Another object of the present invention is to provide a fluid level verification apparatus which can be fabricated as a kit and remain assembled through subsequent handling, transport, and shipping operations. 
         [0015]    Another object of the present invention is to provide a fluid level verification apparatus which can be manufactured to provide convenient means to efficiently assemble the apparatus at a remote location for use with a wide range of devices and other objects of interest without waste of effort, time or motion expended on re-assembly of the apparatus. Specifically, an object of the present invention is to prevent inadvertent dislodging of particular components comprising the invention, such as the bolts in relation to the blocks. 
         [0016]    Another object of the present invention is to protect the transparent inspection tube from mechanical stress during manufacture, transport, handling, shipping, assembly, and use to a wide range of devices and other objects of interest. 
         [0017]    Another object of the present invention is to provide a means to reduce or eliminate stress on the apparatus, whether such stress is due to thermal, mechanical, environmental or chemical agents acting upon the apparatus. 
         [0018]    Another object of the present invention is to provide a means to reduce or eliminate leaking of the fluid flowing through the apparatus. 
         [0019]    Another object of the present invention is to provide for adjustment of the device to increase the ease of installation. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is an exploded isometric view of the present invention; 
           [0021]      FIG. 2  is a detailed, exploded isometric view of a supporting block with a long nipple of the present invention; 
           [0022]      FIG. 3  is a detailed, exploded isometric view of a supporting block with a short nipple of the present invention; 
           [0023]      FIG. 4  a detailed, exploded isometric view of a bolt used in the present invention; 
           [0024]      FIG. 5  is a vertical cross sectional view of the inspection tube of the present invention; 
           [0025]      FIG. 6  is a cross-sectional view of the present invention; and 
           [0026]      FIG. 7  is an enlarged fragmentary, cross-sectional view of a long nipple cooperating block, bolt and inspection tube of the present invention. 
           [0027]      FIG. 8A  is a side view of the present invention in an adjusted compact position. 
           [0028]      FIG. 8B  is a side view of the present invention in an adjusted extended position. 
       
    
    
       [0029]    The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. 
       DETAILED DESCRIPTION 
       [0030]    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 structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
         [0031]    Referring to  FIG. 1 , an improved fluid level verification apparatus  10  of the present invention is shown. The apparatus  10  has a clear inspection tube  11  having a first end  18  and a second end  20 . Also depicted is a pair of end members or supporting blocks  50 A and  50 B, each block  50 A and  50 B having six sides and a pair of mounting bolts  90 . Blocks  50 A and  50 B are depicted as having a long nipple  52 A and a short nipple  52 B, respectively. Each block  50 A and  50 B is removably secured to the inspection tube  11  at the first end  18  and second end  20 , respectively. In turn, each bolt  90  is seated in a respective block  50 A or  50 B. It should be understood that the current invention is not limited to having one of each block  50 A and  50 B or to specific ends of the clear inspection tube  18  and  20  as depicted herein. It is contemplated that there may be two blocks having long nipples. It is also contemplated that the long nipple block  50 A and the short nipple block  50 B may be located on either end  18  or  20  of the clear inspection tube  11  opposite one another. 
         [0032]    Referring specifically to  FIG. 2 , the block  50 A preferably comprises a plurality of faces  58   a    58   b    58   c    58   d    58   e    58   f  and has a cylindrical projection or nipple  52 A, protruding at a generally perpendicular offset from a face  58   a  of the block  50 A. The nipple  52 A has an aperture  82 , which extends through the nipple  52 A from the tip  86  to intersect a bore  56  of the block  50 A, and is oriented generally parallel with the axis of the nipple  52 A. The nipple  52 A is of a predetermined nipple length  84 A and has a concentric channel  70  with a predetermined channel depth  72  and channel height  78 . 
         [0033]    Referring specifically to  FIG. 3 , the block  50 B also preferably comprises a plurality of faces  58   a    58   b    58   c    58   d    58   e    58   f  and has a cylindrical projection or nipple  52 B, protruding at a generally perpendicular offset from a face  58   a  of the block  50 B. The nipple  52 B has an aperture  82 , which extends through the nipple  52 B from the tip  86  to intersect a bore  56  of the block  50 B, and is oriented generally parallel with the axis of the nipple  52 B. The nipple  52 B is of a predetermined nipple length  84 B and has a concentric channel  70  with a predetermined channel depth  72  and channel height  78 . 
         [0034]    Still referring to  FIGS. 1-3 , a tube seal  30  is depicted. The tube seal  30  fits on the nipple  52 A,  52 B and is seated in the channel  70 . In a preferred embodiment, the tube seal  30 , as well as other seals hereinafter described, may comprise an o-ring made from deformable synthetic material, such as nitrile, fluorocarbon, EPDM, and other similar materials. 
         [0035]    Referring now to  FIGS. 1 ,  2 ,  3 ,  6  and  7 , the faces  58   b  and  58   f  of blocks  50 A and  50 B have a depressed annular groove  54 , which locates a concentrically located recessed inwardly tapered bevel  60  and communicates with the coaxial bore  56 . As previously stated, the annular groove  54 , the bevel  60 , and the bore  56  are located on and between the faces  58   b  and  58   f  that are adjacent and generally perpendicular to the nipple  52 A,  52 B. The bore  56  projects through the entire block  50 A,  50 B and intersects the aperture  82  of the nipple  52 A,  52 B. A pair of seals  62  are positioned in each block  50 A,  50 B at the depressed annular grooves  54 , creating a hermetic closure between each seal  62 , the recessed bevels  60 , the bore  56  and a bolt  90 . Again, in the preferred embodiment, the seal  62  may comprise an o-ring or similar structure formed from a deformable material. When assembled, as shown in  FIGS. 6 and 7 , the bolt  90  is placed through the inboard seal  62  and block  50 A,  50 B; the final outboard seal  62  creates an interference fit with a bolt thread  96  and a bolt shaft  102 . 
         [0036]    With reference to  FIG. 4  in particular, the bolt  90  comprises a head  94 , a bolt shaft  102 , a thread  96  and a cylinder  92  with an inner diameter  100 . Interposed on the bolt shaft  102  at a right angle are intersecting bolt holes  108 . The shaft  102  terminates at a bolt head  94 . The bolt head  94  has a bolt face  112  and an underside  114 . The diameter of each of the bores  56  of the respective blocks  50 A and  50 B is larger than the inner unthreaded portion of the bolts  90  to provide sufficient spacing for free flow of fluid through the hollow bore  92  of the bolt  90 , the bolt holes  108 , the bore  56 , the aperture  82  of the nipple  52 A,  52 B and the conduit  14 . 
         [0037]    Now referring to  FIG. 5 , a vertical cross section of the inspection tube  11  is shown in detail. The tube  11  comprises the first end  18 , the second end  20 , a tube length  12 , a conduit  14 , and an outer diameter  16 . A first groove  22  is positioned at a predetermined distance from the tube end  18  having a predetermined groove height  23  and groove depth  26 . The groove depth  26  is selected to accommodate sealing gasket  30 . Furthermore, a second groove  24  is positioned at a predetermined distance from tube end  20  having a respective groove height  25  and groove depth  28 . 
         [0038]    The tube  11  may be manufactured from various substrates such as nylon, polycarbonate, or other synthetic materials. While shown to be cylindrical in shape, it is conceivable that other conduit cross-sectional configurations could be utilized. 
         [0039]    Looking now to  FIGS. 6 and 7 , the inspection tube  11  is removably secured to nipples  52 A and  52 B by means of the tube seal  30  that fits on nipples  52 A and  52 B at the channel  70 . The tube seal  30  positioned in channel  70  of nipple  52 B simultaneously lodges in groove  24  of the inspection tube  11 . 
         [0040]    Continuing to look at  FIGS. 6 and 7 , the apparatus  10  is fully assembled and capable of being connected in fluid flowing relation to an object of interest, such as a tank (not shown). So connected, the compression exerted on the respective bolts  90  at the annular grooves  54  and recessed bevels  60  compress o-rings  62  against the faces  58   b  of the blocks  50 A and  50 B, thus facilitating a hermetic closure. Similarly, the seals  62  resting on the bolts  90  at the junction of the threads  96  and shafts  102 , are compressed at the annular grooves  54  creating a hermetic closure of the seals  62 , the recessed bevels  60 , annular grooves  54  and bores  56  of the bolts  90 . Seals  62  also seal against the tank surface (not shown) to prevent leakage around the threads  96  when the apparatus  10  is mounted to the tank. 
         [0041]    Fluid dispensed from and returning to the object of interest, such as a tank (not shown but including an entrance threaded opening matching the threads  96  of the bolts  90 ), thereby flowing through the bolt  90  by means of the cylinder bore  92 , and the blocks  50 A and  50 B by means of the bore  56  in the blocks  50 A and  50 B, and cooperating with the bolt holes  108 . As shown here, fluid enters the aperture  82  of the nipple  52 B, and fills the conduit  14  of the inspection tune  11  to the liquid level of the tank supporting the inspection tube  11 . 
         [0042]    Referring generally to  FIG. 5  and of particular importance, the inspection tube  11  has grooves  22 ,  24  positioned near the first end  18  and second end  20 , respectively. As previously mentioned, each undercut groove  22 ,  24  of the tube  11  is dimensioned so that the tube seal  30  is seated in the respective groove  22 ,  24 , creating a hermetic closure when the seal  30  is simultaneously fit on the respective nipple  52 A,  52 B and assembled to the tube  11  to provide the apparatus  10  of the present invention. As opposed to the press fit relationship taught in the prior art, a slip fit exists between the inspection tube  11 , seal  30  and nipples  52 A,  52 B. 
         [0043]    As shown here, with further reference to  FIGS. 2 and 3 , the height  25  of groove  24  is substantially similar to that of seal  30  and the channel height  78  of corresponding nipple  52 B. However, groove  22  has a height  23  relatively larger than the seal  30  and the channel height  78  of corresponding nipple  52 A. Additionally, the nipple  52 A has a length  84 A proportionally sized to the height  23  of groove  22 . The length  84 A of nipple  52 A and the height  23  of groove  22  permits movement of block  50 A relative to the inspection tube  11  while maintaining a proper seal with tube seal  30 , thereby providing axial adjustability within the apparatus  10 . The direction of adjustability is shown in  FIGS. 8A and 8B , wherein  FIG. 8A  illustrates the apparatus  10  in a compact position having a distance D1 between the center  91  of bolt  90  and tube end  18 .  FIG. 8B  shows the apparatus  10  in an extended position having a distance D2, larger than distance D1, between the center  91  of bolt  90  and tube end  18 . 
         [0044]    Providing adjustability not only eases installation of the apparatus but also promotes a better seal. For example, when installing the present invention the entrance threaded openings of the tank (not shown) do not have to be spaced apart to an exact distance. Instead, the distance between the openings may actually be within the adjustability range of the apparatus  10 . This not only greatly decreases installation time but also provides a better seal between the blocks  50 A,  50 B and the tank (not shown). Whereas before, a minor mismeasurement, placing the openings too close together or too far apart, meant that at least one block was not perfectly aligned with the center line of the tube  11 , or worse, both blocks were misaligned. Misalignment has been shown to disrupt the ability of seals  30  and  62  to each seal or provide a proper seal. Therefore, adjustability eases installation by permitting an installer to more or less “eye nail” the location of the openings, along with the additional benefit of promoting a better seal throughout as the parts maintain preferred alignment. As stated previously in terms of different embodiments within the purview of the present invention, either tune end  18  or  20 , or both, may have a groove of a predetermined height permitting adjustment of the associated block. 
         [0045]    Moreover, based upon the slip fit relationship between the first groove  22 , the o-ring  30  and the channel  70  of the nipple  52 A, and also the relationship between the second groove  24 , the o-ring  30  and the channel  70  of the nipple  52 B, a hermetic closure is formed with minimal or no mechanical stresses resulting on the inspection tube  11 . By greatly decreasing the radial stresses imparted upon the inspection tube  11 , the expected life of the tube  11  is thereby increased. 
         [0046]    A second important aspect of the invention relates to the formation of the inwardly tapered, recessed bevels  60  and their cooperating coaxial bores  56 . As shown in  FIG. 7 , each of the four recessed bevels has an inner diameter  44  within the concentric bore  56  that is located adjacent the block face  58   b  or  58   f . The inner diameter  44  is less than the recessed bevel outer diameter  46  located at the innermost portion of the concentric bore  56 . The recessed bevel  60  retains the outboard seals  62  and thus prevents displacement of the seals  62  during shipping. The same benefit is derived during installation of the fluid level verification apparatus  10 . By positively retaining the seal  62  within block  50 A, the seal will not become fully or partially dislodged during installation. 
         [0047]    Also, of particular importance is the above described interference fit between the seal  62  and an outwardly extending flange, which may be in the form of the innermost bolt thread  96 . As best seen in  FIG. 7 , the major diameter  48  of the bolt threads is greater than the inner diameter  51  of the seal  62 . Once assembled, the resulting interference fit prevents the bolt  90  from becoming dislodged from the block  50 A,  50 B as commonly occurs with prior art devices, particularly during shipping. This apparatus also provides a benefit during installation, as the installer is free to manipulate the apparatus  10  without the bolts  90  falling free from their associated blocks  50 A,  50 B. Also, the seals or o-rings  62  stay in the recess  60 . This feature aids to prevent pinching of the o-ring during installation. 
         [0048]    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 the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.