Abstract:
A process for using a magnetic aquarium tank wall cleaning tool for cleaning the inner surface of an aquarium having one or more curved interior vertical corners. Magnetic cleaners for aquariums eliminate the need for reaching into the tank or manipulating a cleaner with a long handle. The magnetic tank wall cleaning tool has at least one edge which is curved. The radius of curvature is no more than the radius of curvature of the inner surface of the tank to be cleaned. The cleaner can be manipulated from one flat surface around a curved interior corner by moving the handle horizontally around the corner.

Description:
BACKGROUND OF THE INVENTION 
     The field of the invention is aquarium care products and the invention relates more particularly to magnetic aquarium cleaners utilizing a handle portion which has a magnet on the outer surface of the aquarium and a cleaner portion which also has a magnet which is attracted to the handle portion. 
     A magnetic aquarium cleaner is shown in U.S. Pat. No. 3,208,090. This cleaner has a motive or controller member  6  which moves a moving or follower member  5 . The motive member is manipulated on the outside of the aquarium and the follower member rides along the inner surface of the aquarium wall. The follower is generally rectangular in shape and has two sponges along each edge. While such device is adequate for old style aquariums of the type having flat glass walls, such flat pads are not capable of cleaning the curved inner surface of modern aquariums made of plexiglass. 
     Window cleaners have been used which also utilize magnets and one such window cleaner is shown in U.S. Pat. No. 2,507,559. The magnets used are cylindrical and wrapped in a rectangular pouch  15 . 
     Another magnetic window cleaning device is shown in U.S. Pat. No. 2,634,444. In this case, a rectangular magnet is used and the magnet is wrapped with a cleaning material. 
     A magnetic stirring apparatus is shown in U.S. Pat. No. 2,518,758. The stirrer is rotated by a rotating magnet held below the base of the flask. 
     The problem that exists is two fold. The inner curved corners are very difficult to clean without putting one&#39;s hand and arm inside the fish tank. Because of the potential for transferring germs to or from the aquarium water, this is not desirable. If all the algae is not removed, it quickly forms a nucleus for new hard algae growth. Also, many fish tanks have a canopy which extends over the outer top edge of the tank. The classic magnetic cleaners follow the exterior handle and thus, are not able to reach beyond the overhang of the canopy. Since this leaves a layer of algae, it again forms a nucleus for further algae growth. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a magnetic cleaner for a fish tank which is capable of cleaning both the inner curved surface of a curved corner and the inner surface of an aquarium covered by the exterior flange of a canopy. 
     The present invention is for an aquarium tank inner wall cleaning tool having an outer wall magnet-containing handle and an inner wall magnet-containing cleaner. The improvement of the present invention comprises a curved edge on the wall-contacting face of the cleaner. Preferably, the wall-contacting face has a rigid, generally rectangular face with a top edge, a bottom edge, a first edge wherein the first edge has an extension, and a second edge wherein the second edge has an arcuate curve and the wall-contacting face is covered with a deformable cleaning pad. The deformable cleaning pad is preferably made from the hook portion of a hook and loop fastening assembly. The wall-contacting face of the cleaner is preferably larger than the tank-contacting face of the handle. Also, preferably the first edge of the cleaner extends past the rectangular body of the cleaner. 
     The present invention also comprises a process for cleaning an interior surface of an aquarium tank which has at least one curved vertical corner. The steps include placing an outer wall magnet-containing handle against an area of the outer surface of the vertical wall of the aquarium. Next, an inner wall magnet-containing cleaner is moved against an area of the inner surface of a vertical wall of the aquarium adjacent the handle so that the magnet in the handle attracts the magnet in the cleaner. The cleaner has a curved edge having a radius of curvature no more than the radius of curvature of the curved inner surface of the aquarium to be cleaned. Next, the curved edge of the cleaner is aligned with the curved inner surface of the aquarium and the handle is moved vertically up and down so that the curved edge rides along the curved inner surface of the aquarium and cleans the curved inner surface. The process also includes steps which permit the cleaner to be moved from one flat inner surface to an adjacent flat inner surface. This comprises the steps of moving the handle along the inner edge of one of the flat surfaces in a generally horizontal direction and orienting the handle so that a curved edge of the cleaner is vertically aligned with the inner curved edge of the aquarium. Next, the handle is moved around the outer surface of the corner and because of the curved edge of the cleaner, the cleaner is never separated from the handle enough so that the force of attraction between the magnet of the cleaner and the magnet of the handle holds the cleaner as it goes around the curved corner. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an aquarium, including an aquarium tank having two vertical curved corners. 
     FIG. 2 is a side cross-sectional view of a prior art magnet aquarium cleaning tool. 
     FIG. 3 is a top cross-sectional view analogous to FIG. 2 showing the prior art cleaning tool at the curved vertical corner of the aquarium tank of FIG.  1 . 
     FIG. 4 is an exploded perspective view of the magnet cleaning tool of the present invention. 
     FIG. 5 is a top cross-sectional view of the magnetic cleaning tool of the present invention. 
     FIG. 6 is a top cross-sectional view of the magnetic cleaning tool of the present invention being manipulated around the curved vertical corner of the aquarium tank of FIG.  1 . 
     FIG. 7 is a side cross-sectional view of the magnetic cleaning tool of the present invention adjacent a canopy having a flange which overhangs an upper edge of an aquarium wall. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An aquarium tank is shown in perspective view in FIG.  1  and indicated generally by reference character  10 . Aquarium tank  10  holds a body of water  11  which typically not only contains fish, but various decorations and plants not shown. Tank  10  has a flat front wall  12  with an outer surface  13  and an inner surface  14 . Tank  10  has a right side wall  15  with an outer surface  16  and an inner surface  17 . 
     A curved vertical corner  18  is formed between front wall  12  and right side wall  15 . Such curved corners provide a far more attractive view from the exterior of the aquarium as compared to the metal bracket commonly used in glass aquariums made from flat glass plates. Such brackets obscure the view of the interior of the aquarium, whereas the curved vertical corner  18  permits viewing through the corner, thereby providing a far more attractive appearance. 
     Left side wall  19  has an outer surface  20  and an inner surface  21 . Left side wall  19  and front wall  12  are connected by curved vertical corner  22  which also permits the viewing of the interior through the curved corner. 
     Curved vertical corner  18  has a curved inner surface  23 . Curved vertical corner  22  has a curved inner surface  24 . The tank also has a back  25  and a bottom generally indicated as  26 . 
     The inner wall surfaces become fouled with hard and hair algae and other deposits such as calcium deposits and need to be cleaned in order to provide an attractive aquarium. Because of the importance of maintaining the fish in a disease-free environment, all practical steps are taken to keep the water free from germs. For this reason, it is appropriate to not place one&#39;s hand and arm into an aquarium to clean the inner surfaces. Thus, various cleaning mechanisms have been devised which permit the owner to clean the inner surfaces without contaminating the water. One such system is indicated in FIGS. 2 and 3 of the drawings where a magnet wall-cleaning assembly is shown. As shown in FIG. 2, a handle portion  30  holds a pair of magnets  31  and  32  in a rectangular plastic case  33 . Handle portion  30  is placed against the outer surface  13  of front wall  12 . A cleaner portion  34  also has a pair of magnets  35  and  36  held in a rectangular plastic case  37 . The handle portion  30  and the cleaner portion  34  are typically the same size which makes it difficult to clean an upper portion  38  of inner surface  14  because the flange  39  of canopy  40  overhangs the top  41  of front wall  12 . Thus, handle portion  30  is prevented from being raised above the base  42  of flange  39 . Because of this, the cleaner portion  34  is unable to remove algae from upper portion  38 . Because this portion of the algae remains after cleaning, it readily provides a nucleus for the return growth of algae, making the need for cleaning more frequent. 
     Another disadvantage of the same shaped rectangular magnet assembly of FIG. 2 is indicated in FIG. 3 of the drawings. There, the curved vertical corner  18  has a curved inner surface  23  which the rectangular cleaner portion  34  is unable to properly clean. Also, in attempting to go from the cleaning of the inner surface  14  of front wall  12  to the cleaning of the inner surface  17  of right side wall  15 , one moves the magnet assembly to a position such as that shown in FIG.  3 . The further movement of handle portion  30  around curved vertical corner  18  causes the two magnet assemblies to move so far apart that the handle portion is no longer able to magnetically attract the cleaner portion, which then falls to the bottom of the tank. Thus, in practice, one needs to go through the trouble of removing cover  40 , disassembling the magnet assembly from its position around front wall  12  and reassembling it around right side wall  15 . This simply adds to the time and inconvenience of cleaning the inner surfaces. 
     The aquarium inner wall-cleaning tool assembly of the present invention is shown in FIGS. 4 through 7. In FIG. 4 the handle portion  50  has a top  51  with an overhanging edge  52  which facilitates the grasping of handle portion  50 . A pair of magnets  53  and  54  are held within a rectangular wall portion  55 . A metal plate  56  is positioned behind magnets  53  and  54  and held in position by a spacer  57  within the rectangular wall portion  55 . 
     The cleaner  58  also has a pair of magnets  59  and  60  held in a rectangular wall portion  61 . A metal plate  62  is positioned behind the magnets to increase their magnetic force and the magnet assembly is held within the rectangular wall portion by spacer  63 . Cleaner  58  has a wall-contacting face  64  which is generally rectangular when viewed normal to wall-contacting face  64 . 
     Wall-contacting face  64  is made up of a rigid sheet of plastic  65  which has a top edge  66 , a bottom edge  67 , a first edge  68  and a second edge  69 . Second edge  69  includes a curved face  70  which provides numerous advantages. 
     As shown best in FIG. 5, curved face  70  can be placed adjacent curved inner surface  23  and moved vertically to easily clean this curved inner surface. Preferably, the rigid sheet  65  has a cleaning surface on wall-contacting face  64 . One such effective surface is the hooked portion of a hook and loop fastener of the type sold under the trademark “Velcro.” This cleaning surface is indicated by reference character  71 . 
     The movement of the cleaner  58  from contact with inner wall  14  to contact with inner wall  17  is facilitated by the existence of curved face  70 . It can be seen by viewing FIG. 6 that if curved face  70  formed a right angle, the cleaner  58  would be further from handle  50  than it is by the use of a curved face. The cleaner may be moved from surface  14  to surface  17  by moving handle  50  around the outer edge of curved vertical corner  23  with the curved face leading the turn of the cleaner. This makes the cleaning of the inner surface of the tank easier since it eliminates the necessity of disassembling the two portions of the magnetic cleaner to go from one inner face to an adjacent inner face. Preferably, the radius of curvature of curved face  70  is the same as the radius of the curvature of the tank. In some cases, it is possible that the radius of curvature of curved face  70  is smaller than the radius of curvature of the inner corner  23 . This still permits the cleaning of the inner corner with far greater ease than that possible with the rectangular prior art magnetic cleaner shown in FIGS. 2 and 3. 
     Preferably, the handle portion includes a cloth tank-contacting surface. A preferred type of magnet is a grade 8 ceramic magnet or a rare earth magnet ¾″ to 1″ thick. The magnet assembly of the present invention is also useful for hexagonal corners and corners other than curved corners which are not readily cleaned by the prior art rectangular assembly. 
     As shown in FIG. 7, more of the upper portion  38  of inner surface  14  may be cleaned with the magnetic cleaning assembly of the present invention for two reasons. First, the cleaner is larger than the handle and thus, extends beyond the handle into upper portion  38 . Secondly, first edge  68  includes an extension  72  which extends past rectangular wall portion  61  which further extends the cleaning area of the cleaner  58 . The result is a magnetic cleaning assembly which greatly facilitates the cleaning of the interior of a fish tank, and especially of a fish tank having one or more curved inner corners. 
     As shown in FIG. 1, the cleaning assembly further includes a float  73  affixed to a flexible line  74  tied to cleaner  58 . In the event the cleaner falls to the bottom of the tank, the float facilitates the recovery of the cleaner without having to reach into the tank. 
     The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being 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 intended to be embraced therein.