Abstract:
An apparatus, system, and method are disclosed for retaining solvent. A tray surface extends outward from a solvent sink. The tray surface is inclined toward the solvent sink. One or more tray walls are disposed at a perimeter of the tray surface. The one or more tray walls extend upward from the tray surface. A tray attachment interface supports the tray surface and the one or more tray walls relative to the solvent sink.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Patent Application No. 61/329,010 entitled “APPARATUS, SYSTEM, AND METHOD FOR RETAINING SOLVENT” and filed on Apr. 28, 2010 for Martin D. Ehman and to U.S. Provisional Patent Application No. 61/378,040 entitled “APPARATUS, SYSTEM, AND METHOD FOR RETAINING SOLVENT” and filed on Aug. 30, 2010 for Martin D. Ehman, each of which are incorporated herein by reference. 
     
    
     FIELD 
       [0002]    This invention relates to solvents and more particularly relates to solvent cleaners. 
       BACKGROUND 
       [0003]    A solvent is a material, usually a liquid, that dissolves another material. Solvents have many uses across various industries, and are often used for cleaning. Industries involving machinery or other equipment that become dirty and soiled often use solvents to effectively clean the machinery or other equipment. Some types of solvents even lubricate the objects that they are cleaning. Cleaning with solvents is especially prevalent in the automotive and heavy equipment industries. This is often done in a tank-sink type solvent cleaner common in the field, in which the solvent is stored in a tank, pumped into a tube, and dispersed through a nozzle or brush to clean an object placed in a sink disposed atop the tank. Generally the objects are transported from a work bench for cleaning, then, after cleaning, are again transferred to the work bench. 
         [0004]    Once the objects are clean, however, they can drip solvent on the arms of those holding and moving the clean objects and on other surrounding objects. This wastes solvent that could otherwise be reused to clean other objects. Further, many solvents are flammable, emit dangerous vapors, can cause sores and wounds on the skin, or can be absorbed through the skin to cause other health problems, such as liver, kidney, or brain damage. Allowing solvent to drip on people and on other surrounding objects can be inefficient and dangerous. 
         [0005]    Additionally, even the larger sinks have limitations of space, requiring that objects to be cleaned be frequently transported, usually after cleaning, while still wet and dripping. 
       SUMMARY 
       [0006]    From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that retain solvent. Beneficially, such an apparatus, system, and method would preserve solvent for reuse and protect users and surrounding objects from dripping solvent. 
         [0007]    The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available solvent cleaning systems. Accordingly, the present invention has been developed to provide an apparatus, system, and method for retaining solvent that overcome many or all of the above-discussed shortcomings in the art. 
         [0008]    The apparatus to retain solvent, in one embodiment, includes a tray surface, one or more tray walls, and a tray attachment interface. In further embodiments, the apparatus to retain solvent includes a lip, one or more support arms, one or more shelf openings, lip interface material, support arm interface material, an elongate trough, and/or a drain. 
         [0009]    In one embodiment, the tray surface is formed to extend outward from a solvent sink. The tray surface, in a further embodiment, is inclined toward the solvent sink. The one or more tray walls, in one embodiment, are disposed at a perimeter of the tray surface. In another embodiment, the one or more tray walls extend upward from the tray surface. 
         [0010]    In one embodiment, the tray attachment interface is formed to support the tray surface and the one or more tray walls relative to a solvent sink. The tray attachment interface, in certain embodiments, includes a lip and one or more support arms. In one embodiment, the lip is formed to extend from the tray surface into the solvent sink along an inner surface of the solvent sink. The one or more support arms, in a further embodiment, extend downward from the tray surface and are formed to abut an outer surface of the solvent sink. In certain embodiments, the tray surface, the one or more tray walls, and the lip are integrally formed from a single continuous piece of material, such as a single sheet of metal or the like. 
         [0011]    In one embodiment, lip and the one or more support arms form the one or more shelf openings. The one or more shelf openings, in another embodiment, are disposed between the lip and the one or more support arms. The one or more shelf openings, in a further embodiment, provide space for an upper edge of the solvent sink. 
         [0012]    In certain embodiment, the tray attachment interface includes lip interface material and support arm interface material. The lip interface material, in one embodiment, is disposed between the lip and the inner surface of the solvent sink. The support arm interface material, in one embodiment, is disposed between the one or more support arms and the outer surface of the solvent sink. The lip interface material and the support arm interface material, in a further embodiment, are each formed of padding material that provides friction between the tray attachment interface and the solvent sink. 
         [0013]    In one embodiment, the elongate trough is disposed in the tray surface along an edge of the tray surface adjacent to the solvent sink. The elongate trough, in a further embodiment, is shaped to receive a flange extending from a lid of the solvent sink, so that the tray surface does not prevent the lid from fully closing over the solvent sink. The elongate trough, in one embodiment, includes a drain. The drain of the elongate trough, in certain embodiments, is in fluid communication with the solvent sink and/or a solvent tank. 
         [0014]    A system of the present invention is also presented to retain solvent. The system may be embodied by a solvent tank, a solvent sink in fluid communication with the solvent tank, and one or more solvent retention shelves. The system, in various embodiments, may include a drain, a solvent pump, one or more solvent hoses, a solvent filter, and a lid. 
         [0015]    Each solvent retention shelf, in certain embodiments, is substantially similar to the apparatus to retain solvent described above. In one embodiment, the one or more solvent retention shelves are removable from the solvent sink and are installable in a plurality of positions around the solvent sink. 
         [0016]    In one embodiment, the drain is disposed within the solvent sink. The drain, in a further embodiment, is in fluid communication with the solvent tank. Solvent from the one or more solvent retention shelves, in certain embodiments, runs from the one or more solvent retention shelves into the solvent sink, through the drain, and into the solvent tank. 
         [0017]    In one embodiment, the solvent pump delivers solvent from the solvent tank to the solvent sink through one or more solvent hoses. The solvent filter, in certain embodiments, is between the solvent tank and the solvent pump. The solvent filter, in one embodiment, removes contaminants from the solvent that the solvent pump delivers from the solvent tank to the solvent sink. 
         [0018]    In one embodiment, the lid of the solvent sink is supported in an open position by a fusible material. The fusible material, in a further embodiment, melts to close the lid in response to a fire in the solvent sink. In another embodiment, the lid of the solvent sink includes a flange extending from the lid. 
         [0019]    A method of the present invention is also presented for forming a solvent retention shelf. The method in the disclosed embodiments substantially includes the steps for forming the described apparatus. In one embodiment, the method includes forming one or more tray walls at a perimeter of a tray surface, the tray walls extending upward from the tray surface. The method, in another embodiment, includes forming a lip on the tray surface, the lip extending downward from the tray surface on one edge of the tray surface. In a further embodiment, the method includes attaching one or more support arms to the tray surface, the one or more support arms extending downward from the tray surface, the lip and the one or more support arms forming one or more shelf openings. 
         [0020]    In one embodiment, the method includes placing the one or more shelf openings over an upper edge of a solvent sink. The method, in a further embodiment, includes interfacing the lip with an inner surface of the solvent sink. In another embodiment, the method includes interfacing the one or more support arms with an outer surface of the solvent sink such that the tray surface extends outward from the solvent sink and the tray surface is inclined toward the solvent sink. In certain embodiments, the lip and the one or more support arms support the tray surface and the one or more tray walls relative to the solvent sink. 
         [0021]    These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
           [0023]      FIG. 1  is a perspective view illustrating one embodiment of a system for retaining solvent in accordance with the present invention; 
           [0024]      FIG. 2  is an exploded view illustrating one embodiment of a solvent retention shelf in accordance with the present invention; 
           [0025]      FIG. 3A  is a perspective view illustrating another embodiment of a solvent retention shelf in accordance with the present invention; 
           [0026]      FIG. 3B  is a perspective view illustrating a further embodiment of a solvent retention shelf in accordance with the present invention; 
           [0027]      FIG. 3C  is a perspective view illustrating an additional embodiment of a solvent retention shelf in accordance with the present invention; 
           [0028]      FIG. 4  is a schematic flow chart diagram illustrating one embodiment of a method for forming a solvent retention shelf in accordance with the present invention; 
           [0029]      FIG. 5  is a schematic flow chart diagram illustrating one embodiment of a method for installing a solvent retention shelf in accordance with the present invention; 
           [0030]      FIG. 6  is a partial side cross-sectional view of an embodiment of a solvent retention shelf in accordance with the present invention; 
           [0031]      FIG. 7  is a side elevational view of the embodiment of  FIG. 6  shown in use; 
           [0032]      FIG. 8  is a top plan view of the embodiment of  FIG. 6 ; 
           [0033]      FIG. 9  is a partial side cross-sectional view of the embodiment of  FIG. 6 , showing a drain fitting; 
           [0034]      FIG. 9A  is a partial side elevational view of the embodiment of  FIG. 9 ; 
           [0035]      FIG. 10  is an end elevational view of the embodiment of  FIG. 9 ; and 
           [0036]      FIG. 10A  is a partial end elevational view of the embodiment of  FIG. 9 , showing a removable waste catch screen. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
         [0038]    Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
         [0039]    The schematic flow chart diagrams included herein are generally set forth as logical flow chart diagrams. As such, the depicted order and labeled steps are indicative of one embodiment of the presented method. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the illustrated method. Additionally, the format and symbols employed are provided to explain the logical steps of the method and are understood not to limit the scope of the method. Although various arrow types and line types may be employed in the flow chart diagrams, they are understood not to limit the scope of the corresponding method. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. 
         [0040]      FIG. 1  is a perspective view depicting one embodiment of a solvent cleaning system  100 . The system  100 , in the depicted embodiment, includes a solvent sink  114  with two solvent retention shelves  102  and a solvent tank  116 . The solvent retention shelves  102  provide a surface upon which a user of the solvent sink  114  may place items that the user has cleaned in the solvent sink  114 , allowing the solvent retention shelves  102  to drain excess solvent back into the solvent sink  114  and/or the solvent tank  116 . The solvent retention shelves  102  may conserve solvent and/or prevent solvent from dripping outside of the solvent sink  114 . 
         [0041]    In general, the solvent sink  114  provides a stream of solvent from the solvent tank  116  to clean and rinse soiled objects and returns used solvent to the solvent tank  116 . The solvent sink  114 , in the depicted embodiment, includes an inner surface  118 , an outer surface  120 , an upper edge  122 , a solvent pump  124 , solvent hoses  132 , and a safety system  134 . 
         [0042]    The solvent sink  114 , in one embodiment, is formed of a durable material, such as a metal, a ceramic, or the like. For example, the solvent sink  114  may be formed of stainless steel, cast iron, aluminum, porcelain, fiberglass, a composite of multiple materials, or of another durable material that can withstand contact with various solvents and provide support for mechanical parts and other equipment that may be cleaned in the solvent sink  114 . Depending on the type of solvent used in the solvent sink  114 , in certain embodiments other materials, such as plastics, may be used. The solvent sink  114  and/or portions of the solvent sink  114 , in a further embodiment, may include various layers, treatments, or coatings to increase the durability of the solvent sink  114 . For example, the solvent sink  114  may be coated with enamel, epoxy, or another finish. 
         [0043]    The inner surface  118  of the solvent sink  114  forms a basin that receives the stream of solvent and returns the solvent to the solvent tank  116  through a drain or other opening (not shown) in a base of the inner surface  118 . The inner surface  118  may also provide support for items that a user places in the solvent sink  114  for cleaning. In the depicted embodiment, the inner surface  118  and the outer surface  120  provide support for the solvent retention shelves  102 . The inner surface  118  and the outer surface  120 , in the depicted embodiment, are opposite faces of an exterior wall of the solvent sink  114 . The inner surface  118  and the outer surface  120  have an upper edge  122  over which the solvent retention shelf  102  is placed. The upper edge  122  may include a lip, a rim, or the like that substantially circumscribes the solvent sink  114 . 
         [0044]    The solvent sink  114 , in one embodiment, has a specific size to fit objects for cleaning. In one embodiment, the solvent sink  114  and solvent tank  116  assembly have a height of about 63 inches with the lid  134  open, a width front to back of about 34 ½ inches, a length left to right of about 26½ inches, an inside height within the solvent sink  114  of about 7½ inches, an inside width front to back within the solvent sink  114  of about 32 inches, and an inside length left to right within the solvent sink  114  of about 24 inches. 
         [0045]    The solvent pump  124  is an electrical and/or mechanical pump that delivers solvent from the solvent tank  116  to the solvent sink  114 . In the depicted embodiment, the solvent pump  124  is disposed on an underside of the solvent sink  114 . In further embodiments, the solvent pump  124  may be disposed within the solvent tank  116  or elsewhere in the system  100 . The solvent pump  124 , as depicted, includes an electrical switch  130  to control operation of the solvent pump  124 . In a further embodiment, the solvent pump  124  may be manually actuated, and may include a handle to an actuator which a user can manually handle to pump the solvent into the solvent sink  114 . 
         [0046]    In the depicted embodiment, the solvent pump  124  includes a solvent intake  126  that is in fluid communication with the solvent tank  116  and a solvent output  128  that is in fluid communication with the solvent sink  114 . The solvent intake  126  and the solvent output  128  may include pipes, hoses, tubes, and the like. In one embodiment, the system  100  may include a filter (not shown) between the solvent tank  116  and the solvent pump  124  and/or between the solvent sink  114  and the solvent tank  116  to filter contaminants from the solvent. 
         [0047]    The solvent tank  116  is the source of solvent for the solvent sink  114 . The solvent tank  116 , in the depicted embodiment, includes a drum or barrel. For example, the solvent tank  116 , in one embodiment, is a galvanized drawn steel tank. In other embodiments, the solvent tank  116  may include another type of tank that stores a solvent. The solvent tank  116  may be sized to store a specific amount of solvent, such as sixteen gallons, twenty gallons, thirty gallons, and the like. 
         [0048]    The solvent that the solvent tank  116  stores, in one embodiment, is an industrial solvent used for cleaning. The solvent may include one or more solvents such as alcohol solvents, amide solvents, amine solvents, deuterated solvents, ester solvents, ether solvents, glycol ethers, halogenated solvents, hydrocarbon solvents, inorganic solvents, ionic liquids, ketone solvents, nitro solvents, and the like. One of skill in the art, in view of this disclosure, will recognize other types of solvents suitable for use with the solvent sink  114 . 
         [0049]    The solvent pump  124  pumps the solvent through the solvent output  128  to the solvent hoses  132 . In the depicted embodiment, the solvent hoses  132  include two flex hoses, one with a nozzle attachment and the other with a flow-through brush attachment. One of skill in the art, in view of this disclosure, will recognize that other embodiments of the solvent sink  114  may include a single solvent hose  132 , additional solvent hoses  132 , different types of hose attachments, and/or other arrangements of solvent hoses  132  for cleaning objects with solvent. 
         [0050]    The safety system  134  provides one or more safety features for the solvent sink  114 . Because many solvents are highly flammable, in the depicted embodiment, the safety system  134  includes a lid that is supported by a fusible material that melts in case of fire to close the lid and suppress the fire. In a further embodiment, the safety system  134  may include a fume hood to remove solvent vapors from the air to prevent inhalation of the vapors, ignition or explosion of the vapors, or other harmful effects caused by the vapors in the air. 
         [0051]    The solvent retention shelves  102 , in the depicted embodiment, each include a tray surface  104 , tray walls  106 , a lip  108 , support arms  110 , and shelf openings  112 . While the depicted embodiment includes two solvent retention shelves  102  disposed on opposite sides of the solvent sink  114 , other embodiments may include a single solvent retention shelf  102 , one or more solvent retention shelves  102  on a front or back side of the solvent sink  114 , or the like. 
         [0052]    In the depicted embodiment the solvent retention shelves  102  are removable, and may be rearranged and placed at different locations along the upper edge  122  of the solvent sink  114 . In a further embodiment, one or more solvent retention shelves  102  may be fixedly attached to the solvent sink  114 . For example, a solvent retention shelf  102  may be welded, bolted, integrated with, or otherwise fixedly attached to the solvent sink  114 . Accordingly, in the depicted embodiment, the solvent retention shelves  102  each include a removable tray attachment interface comprising a lip  108 , support arms  110 , and shelf openings  112 . In other embodiments, a solvent retention shelf  102  may include a fixed tray attachment interface with welds, bolts, or the like as described below with regard to the solvent retention shelf connectors  304  of  FIG. 3B . 
         [0053]    The solvent retention shelves  102  retain used solvent by directing the used solvent back into the solvent sink  114  and/or into the solvent tank  116 . Instead of storing recently cleaned items elsewhere, where solvent may drip and run onto other objects, wasting solvent and potentially causing damage, the solvent retention shelves  102  provide a surface directly adjacent to the solvent sink  114  for placing cleaned items. A user of the solvent sink  114  may clean an item in solvent in the solvent sink  114 , place the item on a solvent retention shelf  102 , and the solvent retention shelf  102  returns remaining used solvent from the item to the solvent sink  114  and/or to the solvent tank  116 . 
         [0054]    In the depicted embodiment, the solvent retention shelves  102  channel or drain used solvent back into the solvent sink  114 , where a drain or other opening (not shown) returns the used solvent to the solvent tank  116 . In a further embodiment, the solvent retention shelves  102  may drain used solvent directly into the solvent tank  116 , through an auxiliary opening, or the like, in the solvent tank  116 . 
         [0055]    In one embodiment, a user may use both solvent retention shelves  102  for holding clean items. In another embodiment, a user may use one solvent retention shelf  102  to hold dirty items, may clean the items, and may place the clean items on the other solvent retention shelf  102 , or the like. A user may also use the solvent retention shelves  102  to hold cleaning tools, supplies, or other items. 
         [0056]    The solvent retention shelves  102  may be formed of one or more durable materials, similar to those described above with regard to the solvent sink  114 . In one embodiment, the solvent retention shelves  102  may be formed of a metal such as aluminum, stainless steel, or the like. In another embodiment, depending on the type of solvents used, the solvent retention shelves  102  may be formed of a plastic material. In a further embodiment, different parts of the solvent retention shelves  102  may be formed of different materials. 
         [0057]    In the depicted embodiment, the solvent retention shelves  102  each include a tray surface  104  for supporting items and directing solvent toward the solvent sink  114  and/or the solvent tank  116 . The tray surface  104 , in the depicted embodiment, is substantially flat. In further embodiments, the tray surface  104  may be rounded, may include one or more solvent channels for directing used solvent toward the solvent sink  114 , may include a drain or other opening that is in fluid communication with the solvent tank  116 , or the like. 
         [0058]    The tray surface  104  of each solvent retention shelf  102 , in the depicted embodiment, is inclined toward the solvent sink  114  to return the solvent to the solvent sink  114  and/or the solvent tank  116 . In one embodiment, the incline angle of the tray surface  104  is about six degrees. The incline angle, in another embodiment, is between about five degrees and ten degrees. In a further embodiment, the incline angle may be between about one degree and thirty degrees. In a different embodiment where the solvent retention shelves  102  include a drain that returns solvent directly to the solvent tank  116 , the tray surfaces  104  may be inclined toward the drain instead of or in addition to being inclined toward the solvent sink  114 . 
         [0059]    In the depicted embodiment, the tray walls  106  are disposed at a perimeter of the tray surface  104 , extending upward from the tray surface  104 . The three sides of the tray surfaces  104  that do not face the solvent sink  114 , in the depicted embodiment, are surrounded by the tray walls  106 . In one embodiment, the tray walls  106  retain solvent within the solvent trays  102  and channel the solvent toward the solvent sink  114  and/or the solvent tank  116 . In a further embodiment, the tray walls  106  prevent items placed on the solvent retention shelves  102  from falling off of the solvent retention shelves  102 . 
         [0060]    The tray walls  106  of a solvent tray  102  may be formed with the tray surface  104  of the solvent tray, or may be attached to the tray surface  104  subsequent to formation. For example, in one embodiment, tray walls  106  and a tray surface  104  may be formed from a single, continuous sheet of metal, with the tray walls  106  bent along edges of the tray surface  104 . In another embodiment, tray walls  106  may be welded, bolted, or otherwise attached to the tray surface  104 . 
         [0061]    The tray walls  106  of a solvent retention shelf  102  may be attached to each other, to prevent solvent from leaking out at intersections between them, or the like. For example, the tray walls  106  of a solvent retention shelf  102  may be formed of a continuous piece of material, corners at intersections of the tray walls  106  may be fillet welded, or tray walls  106  may be otherwise attached at intersections between adjacent tray walls  106 . 
         [0062]    The solvent retention shelves  102 , in the depicted embodiment, each include a lip  108 . The lip  108  interfaces with the inner surface  118  of the solvent sink  114  to deliver solvent from the tray surface  104  into the solvent sink  114 . The lip  108  is formed on a side of the solvent retention shelves  102  that is toward the solvent sink  114  and adjacent to the solvent sink  114 . The lip  108  may be integrally formed with the tray surface  104 , for example by bending an edge of the tray surface  104 , or may be otherwise attached to the tray surface  104 , for example by welding or bolting the lip  108  to the tray surface  104 . 
         [0063]    In the depicted embodiment, the solvent retention shelves  102  do not include a tray wall  106  on the sides with the lips  108 . In a further embodiment, a solvent retention shelf  102  may include a tray wall  106  on the side with the lip  108 , and the tray wall  106  may include one or more drain openings through which solvent may drain through the tray wall  106 , over the lip  108 , and into the solvent sink  114 . A tray wall  106  with one or more drain openings, in one embodiment, retains items on the solvent retention shelf  102  while allowing solvent to pass off of the solvent retention shelf  102  and into the solvent sink  114 . 
         [0064]    The solvent retention shelves  102 , in the depicted embodiment, each include two support arms  110 . The support arms  110  interface with the outer surface  120  to support the tray surface  104 . The support arms  110  of a solvent retention shelf  102 , in one embodiment, are integrally formed with the tray surface  104  and/or with the tray walls  106 . In a further embodiment, the support arms  110  of a solvent retention shelf  102  are attached to the tray surface  104  by welds, bolts, screws, and/or other connectors. 
         [0065]    Each support arm  110 , in one embodiment, includes a support arm face (not shown) abutting the outer surface  120 . The lip  108  and the support arms  110 , in addition to providing structural support for the tray surface  104 , orient and position the tray surface  104  relative to the solvent sink  114 . The size, angles, and positions of the lip  108  and the support arms  110  determine the incline angle of the tray surface  104 , and may be selected to provide a desired incline angle. 
         [0066]    The lip  108  and the support arms  110  form one or more shelf openings  112 . The shelf openings  112  provide space for the upper edge  122  of the solvent sink  114 , with any corresponding lip or rim around the upper edge  122 . In the depicted embodiment, to install a solvent retention shelf  102  on the solvent sink  114 , a user places the shelf opening  112  over the upper edge  122  of the solvent sink  114 , positioning the upper edge  122  within the shelf opening  112 . The user lowers the solvent retention shelf  102  until the lower surface of the tray surface  104  contacts the upper edge  122  of the solvent sink  122  and the lip  108  interface with the inner surface  118  of the solvent sink  122 . The user rotates the solvent retention shelf  102  downward until the support arms  110  interface with the outer surface  120  of the solvent sink  114 . 
         [0067]    By interfacing with the inner surface  118  and the outer surface  120  of the solvent sink  114 , the lip  108  and the support arms  110  cooperate to support the solvent retention shelf  102 . In the depicted embodiment, downward pressure on the solvent retention shelf  102  increases pressure between the lip  108  and the inner surface  118  of the solvent sink  114  and between the support arms  110  and the outer surface  120  of the solvent sink  114 , supporting the solvent retention shelf  102 . 
         [0068]      FIG. 2  is an exploded view depicting one embodiment of the solvent retention shelf  102 . In the depicted embodiment, the solvent retention shelf  102  is substantially similar to the solvent retention shelves  102  depicted in  FIG. 1 . The solvent retention shelf  102  includes the tray surface  104 , the tray walls  106 , the lip  108 , the support arms  110 , and the shelf openings  112  and further includes solvent guides  202 , lip interface material  204 , support arm interface material  206 , support arm faces  208 , connectors  210 , tray connector interfaces  212 , and support arm connector interfaces  214 . 
         [0069]    In the depicted embodiment, the tray surface  104 , the tray walls  106 , and the lip  108  are each formed from a single, continuous sheet of metal, with the tray walls  106  bent up along three edges of the tray surface  104  and the lip  108  bent down along a fourth edge of the tray surface  104 . In the depicted embodiment the support arms  110  are formed separately from the tray surface  104 . In one embodiment, the tray surface  104 , the tray walls  106 , the lip  108 , and/or the support arms  110  are formed from a sheet of aluminum. In a further embodiment, the tray surface  104 , the tray walls  106 , the lip  108 , and/or the support arms  110  are formed from a 10 gauge sheet of metal that is about 0.09 inches thick. 
         [0070]    The solvent retention shelf  102  may be sized to fit a specific size or design of solvent sink  114 . In one embodiment, the solvent retention shelf  102  has dimensions of about 18½ inches front to back, about 19 inches left to right, and about 6 inches high. One of skill in the art, in light of this disclosure, will recognize other dimensions for a solvent retention shelf  102  to fit various sizes and designs of solvent sinks  114 . 
         [0071]    The connectors  210  connect the support arms  110  to the tray surface  104  by interfacing with the tray connector interfaces  212  and the support arm connector interfaces  214 . In the depicted embodiment, the connectors  210  are cap screws and the connector interfaces  212 ,  214  are threaded holes. The connectors  210 , cap screws in the depicted embodiment, may be counter sunk into the tray connector interfaces  212  such that the connectors  210  are flush with the tray surface  104 . In further embodiments, the connectors  210  may include bolts, welds, glue, and/or other types of connectors. 
         [0072]    The depicted embodiment includes solvent guides  202  that prevent solvent from dripping off of an edge of the tray surface  104  and/or the lip  108 . The solvent guides  202 , in the depicted embodiment, are disposed along an edge of the tray surface  104  and the lip  108  at an intersection of the tray surface  104  and the lip  108 . In a further embodiment, the solvent guides  202  may be disposed along an edge of the tray surface  104  or the lip  108  without extending along an edge of the other. The solvent guides  202 , in one embodiment, are formed of a durable material, such as metal, plastic, rubber, or the like. 
         [0073]    In the depicted embodiment, the solvent guides  202  are separate from and attached to the tray surface  104  and the lip  108  using an adhesive, welding, or the like. In a further embodiment, the solvent guides  202  may be integrally formed with the tray surface  104  and/or the lip  108 . For example, the solvent guides  202  may include a raised bump in the tray surface  104  and/or the lip  108 , a wall formed by bending an edge of the tray surface  104  and/or the lip  108 , or the like. In one embodiment, the solvent guides  202  are an extension of the tray walls  106 . 
         [0074]    The depicted embodiment further includes lip interface material  204  and support arm interface material  206 . The lip interface material  204  and the support arm interface material  206 , in one embodiment, are placed at locations where the solvent retention shelf  102  interfaces with the solvent sink  114  to prevent the solvent retention shelf  102  from damaging the solvent sink  114  and to prevent movement of the solvent retention shelf  102  while installed on the solvent sink  114 . The lip interface material  204  and the support arm interface material  206  may be formed of rubber, plastic, foam, fabric, leather, or another material that provides padding and/or friction between the solvent retention shelf  102  and the solvent sink  114 . 
         [0075]    In the depicted embodiment, the lip interface material  204  is disposed on an underside of the lip  108  and on at least a portion of the tray surface  104  adjacent to the lip  108 . When the solvent retention shelf  102  is installed on the solvent sink  114 , the lip interface material  204  is disposed between the lip  108  and the inner surface  118  of the solvent sink  114  and between the tray surface  104  and the upper edge  122  of the solvent sink  114 . In other embodiments, the lip interface material  204  may be disposed on the lip  108  but not on the tray surface  104 , or vice versa. 
         [0076]    The support arm interface material  206 , in the depicted embodiment, is disposed on the support arm faces  208 . The support arm faces  208  are disposed at an end of the support arms  110  toward the solvent sink  114  for abutting the outer surface  120  of the solvent sink  114 . The support arm interface material  206  is disposed between the support arm faces  208  and the outer surface  120  of the solvent sink  114  when the solvent retention shelf  102  is installed on the solvent sink  114 . 
         [0077]      FIG. 3A  is a perspective view depicting another embodiment of the solvent retention shelf  102 . In the depicted embodiment, the solvent retention shelf  102  is substantially similar to the solvent retention shelves  102  of  FIG. 1  and the solvent retention self  102  of  FIG. 2 . The solvent retention shelf  102  includes the tray surface  104 , the tray walls  106 , the lip  108 , the support arms  110 , the shelf openings  112 , and the support arm faces  208  and further includes solvent channels  302 . 
         [0078]    The solvent channels  302  channel solvent along the tray surface  104  toward the lip  108 . The solvent channels  302  may be integrally formed with the tray surface  104 , such as bumps formed in the surface of the tray surface  104  using a die or the like, or the solvent channels  302  may be affixed to the tray surface  104 . The solvent channels  302  may be formed of metal, rubber, plastic, or another durable material. In one embodiment, the solvent channels  302  further provide friction to prevent items from sliding down the tray surface  104  while allowing solvent to flow down the tray surface  104 . 
         [0079]      FIG. 3B  is a perspective view depicting a further embodiment of the solvent retention shelf  102 . The solvent retention shelf  102  includes the tray surface  104 , the tray walls  106 , the lip  108 , the support arms  110 , the shelf openings  112 , a support arm face  208  and further includes solvent retention shelf connectors  304 . 
         [0080]    In the depicted embodiment, the tray surface  104  and the tray walls  106  are formed of a single material and are rounded to facilitate draining of solvent toward the lip  108 . The lip  108 , in the depicted embodiment, is an edge of the tray surface  104 , and is not for interfacing with the inner surface  118  of the solvent sink  114 . Instead, the solvent retention shelf  102 , in the depicted embodiment, includes one or more solvent retention shelf connectors  304 . In the depicted embodiment, the solvent retention shelf connectors  304  are holes for bolts, screws, or the like for directly connecting the support arm face  208  to the outer surface  120  of the solvent sink  114 . While the depicted embodiment includes a single support arm  110 , other embodiments may include two or more support arms  210 . 
         [0081]      FIG. 3C  is a perspective view depicting an additional embodiment of the solvent retention shelf  102 . The solvent retention shelf  102  includes the tray surface  104 , the tray walls  106 , the lip  108 , the support arms  110 , and the shelf openings  112 . While the embodiments of the solvent retention shelf  102  depicted in  FIGS. 1 ,  2 ,  3 A, and  3 B are each formed of substantially solid, continuous material, the embodiment depicted in  FIG. 3C  is formed of wire or rods that are bent and/or connected to form the solvent retention shelf  102 . 
         [0082]    The solvent retention shelf  102 , in the depicted embodiment, allows solvent to drip or run through the tray surface  104 . The solvent retention shelf  102  may be used over an additional tray, container, or the like to collect the solvent or to deliver the solvent to the solvent tank  116 . 
         [0083]      FIG. 4  is a schematic flow chart diagram depicting one embodiment of a method  400  for forming the solvent retention shelf  102 . The method  400  begins, and a shelf assembler forms  402  the tray walls  106  on the tray surface  104 . The shelf assembler may include one or more automated assembly devices, assembly workers, assembly tools, or the like. The shelf assembler may form  402  the tray walls  106  on the tray surface  104  by bending material at one or more edges of the tray surface  104 , attaching the tray walls  106  to the tray surface  104 , or the like. 
         [0084]    The shelf assembler forms  404  the lip  108  on the tray surface  104 . The shelf assembler may form  404  the lip  108  by bending material at an edge of the tray surface  104 , attaching the lip  108  to the tray surface  104 , or the like. The shelf assembler attaches  406  the support arms  110  to the tray surface  104 . The shelf assembler may attach  406  the support arms  110  to the tray surface  104  by bending material at one or more edges of the tray surface  104 , attaching the support arms to the tray surface  104 , or the like. In one embodiment, the shelf assembler attaches  406  the support arms  110  to the tray surface  104  by interfacing the connectors  210  with the tray connector interfaces  212  and/or the support arm connector interfaces  214 . The shelf assembler attaches  408  the lip interface material  204  to the lip  108  and/or the tray surface  104  and attaches  408  the support arm interface material  206  to the support arm faces  208  and the method  400  ends. 
         [0085]      FIG. 5  is a schematic flow chart diagram illustrating one embodiment of a method  500  for installing the solvent retention shelf  102  on the solvent sink  114 . A shelf installer positions  502  the upper edge  122  of the solvent sink  114  within the shelf opening  112  of the solvent retention shelf  102 . The shelf installer may include one or more automated assembly devices, assembly workers, assembly tools, a user of the solvent sink  114 , or the like. For example, the shelf installer may position  502  the upper edge  122  of the solvent sink  114  within the shelf opening  112  of the solvent retention shelf  102  by placing the shelf opening over the upper edge  122  of the solvent sink  114 , or the like. 
         [0086]    The shelf installer interfaces the lip  108  with the inner surface  118  of the solvent sink  114 , for example by lowering the solvent retention shelf  102  until the lower surface of the tray surface  104  contacts the upper edge  122  of the solvent sink  122  and the lip  108  contacts the inner surface  118  of the solvent sink  122 . The shelf installer interfaces  506  the support arms  110  with the outer surface  120  of the solvent sink  114 , for example by rotating the solvent retention shelf  102  downward until the support arms  110  contact the outer surface  120  of the solvent sink  114 . By interfacing with the inner surface  118  and the outer surface  120  of the solvent sink  114 , the lip  108  and the support arms  110  cooperate to support the solvent retention shelf  102 . 
         [0087]    In some cases, the lid of the solvent sink has a flange facing downward and around the edges of the sink when in place on the solvent sink, in order to better suppress fire and further other safety objectives. In such cases, the solvent retention shelf  602  shown in  FIGS. 6-10A  can be used. ( FIGS. 6-10A  are engineering drawings showing dimensions and the like in addition to reference figures.) 
         [0088]    Referring particularly to  FIGS. 6 and 7 , the shelf  602  differs from the shelf  102  in that it includes an elongate trough  604 , which allows for any flange  606  from the lid  134  to enter the trough  604  rather than abut the shelf  102  and prevent the lid  134  from closing completely. The shelf openings  112  of the shelf  602  may be enlarged to accommodate the flange  606 , if necessary. In the depicted embodiment, the trough  604  is disposed along an edge of the tray surface  104  adjacent to the solvent sink  114 . The trough  604  may be substantially parallel to an upper edge  122  of the solvent sink  114 , or may otherwise be shaped to receive a flange of the lid  134  as it closes over the solvent sink  114 . 
         [0089]    Referring now additionally to  FIG. 8 , the shelf  602  may include diverting ribs  608  to enhance the flow of solvent from the shelf into the trough  604 . It can be seen that the trough  604  interrupts the flow of solvent from the shelf  602  into the sink  114 , making it desirable to collect the solvent for further use. Such collection could take place at the ends of the trough  604  or by other means, or through use of a drain hole  610  disposed in the trough  604 —in the embodiment shown, it is located approximately at the midpoint of the trough  604 . The trough  604  may slope slightly toward the drain hole  610  in order to urge the flow of solvent toward it rather than toward the open ends of the trough. The ends may also be closed, if desired. As shown in  FIGS. 9-10A , the drain  610  may include a drain fitting  612  made of brass or other material and placed in the drain  610 . The fitting  612  may be welded or otherwise affixed in the drain  610  to ensure that solvent drains through the fitting  612  and not around it. 
         [0090]    As shown in  FIGS. 10 and 10A , the fitting  612  includes an appendage  614  on which are formed ridges  616 , which tend to keep a drain tube (not shown) placed on the appendage  614  from sliding off. In this way, solvent draining into the trough  604  goes through the fitting  612 , appendage  614 , and into the drain tube, which can be directed toward the sink  114  or directly into the tank  116 , to be stored for further use. 
         [0091]    The fitting  612  may be disposed in a depression  618 . Additionally, a waste catch screen  620  may be disposed in the fitting  612  to filter out impurities from the solvent. The waste catch screen  620  may be removable for cleaning. 
         [0092]    The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.