Air and water flow system for aquarium
BACKGROUND OF THE INVENTION 
     Many homes and offices display an aquarium containing small colorful exotic fish. The aquarium is usually lighted so as to be a dramatic eye-catching exhibit. Much attention has been paid to making the aquarium as attractive as possible, with glass walls on all sides to provide maximum visibility. In order to keep the aquarium water clean and life supporting, it has been necessary to include means for bubbling air upwards through the water as well as employing charcoal filters and the like. Normally this is accomplished by tubing leading from an air pump outside the aquarium over the top of a wall and down the inside to the bottom of the tank where it is discharged to bubble upwards through the water. If more than one bubbling location is desired, more than one set of air tubing must be employed. Furthermore, if a toy article, such as a sea chest, a diver, a moving grandfather&#39;s clock, or the like, is to be used with air bubbles emanating from the article, there is still another set of air tubing required. It is obvious that the tubing used to deliver the air to various locations on the bottom of the aquarium are &#34;eyesores&#34; which detract from the beauty of the aquarium. There also may be inlet and drain lines for introducing or draining water from the tank, necessitating still another set of unsightly tubing to mar the appearance of the aquarium. 
     It is an object of this invention to provide an improved system of introducing air and water into and removing water and debris from an aquarium. It is still another object of this invention to provide an aquarium which has no visible air or water lines. Other objects will appear from the more detailed description which follows. 
     BRIEF DESCRIPTION OF THE INVENTION 
     This invention relates to an aquarium having at least one vertical wall and a bottom wall and having air and water lines passing through a fixture in said vertical wall adjacent the bottom wall, a perforated support sheet spaced upwardly from and covering substantially all of said bottom wall, said support sheet adapted to be covered with a bed of gravel and other items to resemble the floor of a body of water, air lines substantially unnoticeable from outside said aquarium and leading from said fixture under said support sheet and discharging upwardly at selected locations under said bed of gravel, flow control means in the form of adjustable valves are included in said fixture and accessible outwardly of the aquarium to adjust the air flow to any selected rate and to adjust the flow of water into or out of said aquarium or to completely block the flow in either direction. 
     In a specific embodiment of this invention the fixture is a threaded plug which passes through an opening in the aquarium wall and is fastened to the wall with washer-seals on either side of the aquarium wall and a nut threaded onto the plug to squeeze the washer-seals tightly against such wall thereby preventing any water leakage. The fixture body contains several conduits extending through from one end to the other end of the body and fitted with adapters for attachment of tubing thereto. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a perspective view of the air and water flow system installed in an aquarium according to this invention. 
     FIG. 2 is a partial cross-sectional view taken along line 2--2 of FIG. 1. 
     FIG. 3 is a partial cross-sectional view taken along line 3--3 of FIG. 1 showing the fixture according to this invention through a wall of the aquarium. 
     FIG. 4 is an elevational view of the fixture end outside the aquarium of FIG. 3. 
     FIG. 5 is a cross-sectional view taken along line 5--5 of FIG. 3. 
     FIG. 6 is an elevational view of the fixture end inside the aquarium of FIG. 3. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The general features of the aquarium of this invention may be appreciated from the drawings of FIGS. 1 and 2. The aquarium is a glass or plastic tank of any convenient number of walls although the most common is a rectangular structure of two side walls 10, two end walls 11, and a bottom wall 12 sealed together by known silicone sealant or the like and often contain opaque corner reinforcements 20 to make a transparent tank that will hold water. Other shapes including curved or planar walls of whatever number and configuration are equally useful in the operation of this invention. 
     On any selected wall 10, 11, or 12 there is a fixture 13 which extends through a passageway 45, as seen in FIG. 3, in the wall to which it is attached so as to have one end 22 inside the tank and the other end 21 outisde the tank. The location of fixture 13 is adjacent the bottom of any side wall 10 or end wall 11 and spaced slightly above the bottom wall 12. Fixture 13 may be placed through bottom wall 12 and spaced slightly from the bottom edges of walls 10, 11 or 12, so that it is convenient for the operator to reach dependent on where the aquarium is to be located. However, back wall or end wall mounting of fixture 13 is preferred. Through fixture 13, as will be explained below in detail, there passes the conduits for bringing air into the aquarium and for conducting water into or out of the aquarium. Air lines 14 and water line 15, with removeable screen filter 42, are shown attached to the inside end of fixture 13 and extend to whatever location is desired adjacent bottom wall 12. Fixture 13 includes means 23 for controlling the flow rates of air and water through the various conduits in fixture 13. Line 48 connects fixture 13 to a source of water or to a drain. 
     Overlying all of lines 14 and 15, as seen in FIG. 1, and all of bottom wall 12 is a support sheet 17 having a plurality of perforations in the form of slits 24 in spaced locations, slits 24 being sufficiently large to permit passage of air, water and fish food or fish excrement or the like in either direction. Support sheet 17 is maintained spacedly above the bottom wall by spaced pads 50 located at the corners of the aquarium and generally medially thereof to provide support for a bed of gravel or rocks 18 as is usually found in the bottom of an aquarium and whatever toys 19 as may be desired. Sheet 17 may be fitted with pipe nipples 16 to be connected to an air line 14 underneath sheet 17 and/or connected to line 46 conducting air to a toy 19. It is to be understood that in this fashion air may be caused to bubble from any desired location or locations in the gravel bed 18, including corner discharges 17, discharges 16 at any location under bed 18, and discharges through toys 19. Sheet 17 may be bendable to contour same into hills and valleys in gravel bed 18 and can be bent to overlie fixture 13 and keep it out of sight or the sheet 17 may be preformed to include a hill portion 51 generally medially of the back wall 52 and/or end walls 11. 
     In FIGS. 3-6 there are shown the details of fixture 13. Fixture 13 comprises a body 25 having a shoulder 29 and an external threaded portion 30, a nut 26 which is threaded onto portion 30 and two washer-seals 27 and 28. Body 25 passes through a passageway or opening 45 in the glass wall 10 of the aquarium, and is fastened thereto by tightening nut 26 so as to squeeze washer-seals 27 and 28 between nut 26, shoulder 29 and the surfaces of wall 10. A silicone type of sealant may also be used in the opening 45 and between washer seals 27 and 28 and the inner and outer surfaces of glass wall 52 surrounding opening 45. Internally of fixture 13 are passageways for air and for water. Inlet air enters through passageway 31 and exits through a plurality of passageways 32. Water is conducted through passageway 35 in both directions depending on whether it is used to add water to or drain water from the aquarium. In each air outlet line 32 there is a screw thread throttle valve means 43 having a pointed or needle valve end portion to regulate the flow of air therethrough. In water line 35 there is a screw thread valve means including screw 38 and seal 39 affixed thereto to open or close water line 35. A lateral passageway 37 intersects line 35 to permit screw 38 to function as a shut-off valve. Adapter 44 and adapters 40 are employed to permit connection of the air lines 31 and 32, respectively, to plastic hoses, if desired. Similarly an adapter or connector 41 is employed to permit connection of lateral passageway 37 to a flexible rubber hose 48. Hose 15 is shown connected on the inside end of fixture 13 to provide fresh water to or remove contaminated water from the aquarium. Passageways 33 are merely convenience holes produced in drilling the cross connections from air inlet line 31 to air outlet lines 32 and the passageways 33 are closed by plugs 34 so as to direct the air from inlet line 31 to outlet lines 32. This arrangement makes it possible to have all flow control means 43 and 38 to be available at one location on the outside end of fixture 13 and located in an unobtrusive position. 
     Fixture body 25 and nut 26 are preferably manufactured from a suitable plastic, but may be metal, with washer-seals 27 and 28 preferably an elastomeric material such as rubber, nylon, etc. An appropriate sealant to help fasten fixture 13 into the glass wall 10 is a silicone adhesive which is not affected by water and forms a tight seal with glass, metal, and plastics. 
     It is contemplated that the fixture may include only two side air passageways 32 with the uppermost passageway being made in conformance with water passageway 35 whereby an external charcoal filter or the like could be provided with water from line 15 exiting from the tank via connector 41 and line 48 to such filter and returned from such filter via appropriate lines to the conformed water passageway, identical to passageway 35, and having a control valve identical to flow control means 38. Of course, such conformed passageway would not communicate with air inlet line 31 and the lateral passageway 33 would be made in conformance with passageway 37 and another connector, identical to connector 41, would be employed to permit connection to another flexible rubber hose, identical to hose 48. 
     While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.