Leak free semi-stackable drain pan

Abstract

The present invention relates to drain pans and the process of making the same, and more particularly to a leak proof drain pan that is semi-stackable during storage and can be manufactured from a single piece of steel without the use of a press, die or tooling. The drain pan includes corner sections created from a unique folding system which eliminates seams and thus the need for any sealing of the seams.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to drain pans, and more particularly to a leak proof drain pan that is semi-stackable during storage and can be manufactured from a single piece of steel without the use of a press, die, welding or tooling.

2. Description of the Prior Art

Various types of drain pans are known in the art and can be used in any number of situations for collecting various types of fluids such as oil or water. Such drain pans should be leak free, but require sealants to effectively seal the seams of the drain pan. Drain pans exist in the automotive and trucking industries, and can be used for heavy duty truck and trailer tubeless dual wheels, allowing the user to cleanly and safely drain oil or grease from the axles. Drain pans can also be used in the food industry, where drain pans are placed underneath frying machines to catch cooking oil and grease dripping or to completely drain the cooking oil. Drain pans can be used for water heaters to catch excess water. A household dishwasher can include a drain pan designed to relocate leaking fluids to an observable location. Other types of appliances that can use drain pans include refrigerators and washing machines for catching excess water leaking from the appliance. Drain pans can be used to catch excess grease from underneath barbecue grills and inside home grills.

A cooling coil used in air conditioning apparatus such as furnaces, air handling units, and heat pumps extracts moisture from the air which is being flowed externally across the coil (by a blower portion of the apparatus) and cooled by the coil for delivery to a conditioned space served by the apparatus. Air flowing across the coil is dehumidified as it is cooled, causing condensation to form on the coil. This condensation must be disposed of to prevent freezing of the coil and damage to the surrounding building structure. Typically, a drain pan is located beneath the coil to receive condensate runoff. The pan includes an opening in a bottom part of the pan to conduct the condensate accumulated in the pan to an external drainage conduit.

It is advantageous to reduce water retention in the pan to the extent feasible, not only to reduce the likelihood of condensate spillage from the pan onto the adjacent building structure, but also to inhibit the formation of mold, rust and other undesirable byproducts of stagnant water in the pan which may lead to reduction in the quality of air delivered to the conditioned space. Further, air flowing across the heat exchanger cooling coil may pick up moisture from excessive water accumulation in the pan, which may result in unwanted humidity in the air supplied to an indoor space.

Drain pans of various types are known in the art. These prior art drain pans are typically rectangular in shape and cannot fit inside one another when stacked for storage. Because of limited availability of shelf space in retail establishments, it is desired to stack the drain pans as closely together as possible. FIG. 10 of the present application shows a typical set of stacked drain pans according to the prior art. As can be seen, the drain pans of the prior art are stacked one on top of another and are not nested together. Thus, stacking multiple drain pans for storage, shipping, etc. will take up more space.

U.S. Pat. Nos. 4,632,268 and 4,513,865 disclose stackable oil drain pans. As can be seen from FIGS. 4 and 5 of both references, the drain pan has a male protrusion on top of the pan and a corresponding female indentation on the bottom. When stacked on top of each other, the drain pans do stack more easily. However, the amount of excess space saved from stacking is relatively small. As can be seen from the FIGS. 4 and 5, the main body of the drain pans do not fit inside one another.

Some of the prior art drain pans are nestable when stacked. A typical drain pan of this nature is shown in U.S. Pat. No. 6,718,788. However, this drain pan has a big disadvantage based on the manufacture of the drain pan itself. The drain pan is fabricated by use of a press, die and tooling. The drain pan is pressed into a die and the corners are crimped to form the usual rectangular shape with crimped corners. The type of press used is a large hydro-formed press which includes tooling to manufacture only one size at a time. Each different size drain pan requires a different die with separate tooling. Since the die and tooling must be custom made to accommodate each drain pan size, the manufacturing costs are high. Thus, manufacture of this type of drain pan is very expensive and is not easily adaptable for fabricating different size drain pans unless large numbers of each size of pan are made.

Furthermore, during the foregoing manufacturing process using the press, the large force exerted by the press to form the drain pan can cause the steel to crack at the corners. If these cracks are not found at the time of manufacture, this can create possible leakage of the condensate when the drain pan is in use. Hair-line cracks in steel are often not visible to the naked eye. Therefore, the prior art drain pans have some major disadvantages.

Some of the prior art nestable pans, such as the drain pan disclosed in U.S. Pat. No. 6,718,788, can become jammed when stacked, making removal of the pans tedious and slow. If there is tight stacking, it might not be possible to separate the drain pans.

It would be advantageous to reduce the amount of space the drain pans occupy when stacked upon one another for storage or shipping purposes. In this regard, it would be useful for a drain pan to fit inside another drain pan.

Furthermore, it would be an advantage to significantly reduce the costs and time associated with the manufacture of drain pans by eliminating the need for a die and tooling to be used with a press. The elimination of the press during the manufacturing process would also reduce the likelihood of cracks or flaws in the drain pan.

As can readily be seen from the foregoing, a need exists for a drain pan structure which eliminates or at least substantially reduces the above-mentioned problems, limitations and disadvantages of conventionally constructed drain pans. It is to this need that the present invention is directed.

SUMMARY OF THE INVENTION

As described in the Description of the Prior Art, drain pans are known in the art and can be used in any number of situations for collecting various types of fluids such as oil or water in the form of condensation. Such drain pans should be leak free, but require sealants to effectively seal the seams of the drain pan.

An object of the present invention is to provide a drain pan which is leak proof and can be manufactured without the need of a press, die and tooling.

Another object of the present invention is to provide a drain pan which can be manufactured easily at relatively low cost and is easily adaptable for being manufactured in various sizes.

Yet another object of the present invention is to provide a drain pan that can be manufactured from one piece of steel or other appropriate metal, wherein the single piece of steel or other metal is folded upon itself to form the drain pan, without the formation of hairline or other types of cracks.

A further object of the present invention is to provide a drain pan which is semi-stackable for reducing the space on the shelves of wholesalers and other storers of such pans.

Another object of the present invention is to provide a drain pan which does not require the use of sealants to prevent leaks.

Still yet another object of the present invention is to provide a drain pan with a drain plug that can be located on any side of the drain pan for preventing overflow of the pan.

The foregoing objects are achieved according to the preferred embodiment of the invention by the provision of a drain pan from a single piece of sheet metal which is uniquely folded to create a seamless drain pan. The drain pan includes folded corner sections which are folded toward the inner portion of the drain pan as described below, which enables the stacking of the drain pans in a stable manner, with easy placement of drain pans in the stack and fast removal therefrom, without any possibility of jamming.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the present invention will emerge from reading the detailed description hereinbelow of nonlimiting embodiments of the invention, and examining the attached drawings wherein:

FIG. 1 is a perspective view of the leak free semi-stackable drain pan.

FIG. 2 is a section view of the drain pan of FIG. 1 taken along the line 2-2.

FIG. 3 is a section view of the drain pan of FIG. 1 taken along the line 3-3.

FIG. 4 is an enlarged perspective view of an unfolded corner of the drain pan of FIG. 1 showing dotted lines where the drain pan will be folded.

FIG. 5 is an enlarged perspective view of a partially folded corner of the drain pan of FIG. 1 showing the direction of the folds indicated by arrows.

FIG. 6 is an enlarged perspective view of a corner of the drain pan of FIG. 1 showing the direction of the final fold of indicated by arrows.

FIG. 7 is an enlarged perspective view of a corner of the drain pan of FIG. 1 showing a completely folded corner with completely folded top edges.

FIG. 8 is a top view of the drain pan of FIG. 1 as a single sheet of metal completely unfolded, prior to its fabrication into a drain pan.

FIG. 9 is a front view of multiple drain pans of FIG. 1 placed upon one another in a semi-stackable fashion.

FIG. 10 is a front view of multiple drain pans according to the prior art in a stacked configuration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As discussed throughout the specification, the term “crimp” or “crimped” means corrugated or to produce a corrugated surface. The term “semi-stackable” means that one drain pan is inserted with its open top facing upwards, into a lower drain pan with its open top facing upwards, with the upper edge of the inserted end wall contacting the inside of the corresponding end wall of the drain pan into which the inserted drain pan is being placed, and the lower edge portion of the opposite end wall of the inserted drain pan resting on the upper edge of the end wall of the lower drain pan so that the drain pan at the top of the stack can be easily grasped to enable lifting of the pan from the stack. The inclination of the next drain pan in the stack is reversed to limit the tilting of the stack. An example of stacking of the semi-stackable drain pan is shown in FIG. 9.

Disclosed according to the present invention is a drain pan and a method of producing the drain pan. As will be more fully explained hereinafter, the drain pan of the present invention is preferably folded from a single sheet of steel or similar material without the use of a press and the necessary die and tooling associated with the press. The drain pan is semi-stackable for reducing the space on the shelves of wholesalers, and making removal of one or more drain pans easy whether done manually or with an appropriate tool or appropriate equipment.

FIG. 1 shows a perspective view of the leak free semi-stackable drain pan generally designated at 10. Drain pan 10 is seamless and does not leak. As shown, drain pan 10 is substantially square shaped and includes a bottom wall 12 which can have a width of about 24 inches width and a length of 24 inches. However, drain pan 10 is not limited by these dimensions or being substantially square shaped and could retain other shapes such as a rectangle, for example, depending upon the application of the drain pan and the different sizes of the air conditioner. Drain pan 10 could also be curved or have irregular shapes as well. Drain pan 10 also includes a front wall 14, a rear wall 16 and two side walls 18. Front wall 14 and rear wall 16 are substantially parallel to each other and substantially perpendicular to bottom wall 12. Side walls 18 are also substantially parallel to each other and substantially perpendicular to bottom wall 12. Front wall 14 and rear wall 16 are substantially perpendicular to sidewalls 18. As seen in FIG. 1, side walls 18 also include corner sections 20 on the inside of drain pan 10 resulting from the folding of the corners of drain pan 10 as discussed later. Top edge portions 22A, 22B and 22C are located on the inside of front wall 14, rear wall 16 and side walls 18 respectively, and are modified as described below, to serve to protect a user handling drain pan 10 from any sharp edges of the sheet metal. Top edge portion 22C overlaps corner sections 20 of each sidewall 18 as shown in FIG. 1. A drain fitting 24 is located on the outside of front wall 14 to drain the water or condensation retained by drain pan 10. In use, drain fitting 24 is hermetically sealed in drain pan 10 and thus does not have any leaks. When installed in an air conditioner, freezer or refrigeration unit, for example, a hose is attached to drain fitting 24 in the manner shown in U.S. Pat. No. 6,718,788 for draining condensates from drain pan 10. Drain fitting 24 can advantageously include as an integral unit, a cylindrical tube or male adaptor 25A extending from a nut portion 25B from which extends an externally threaded tubular portion extending through wall 14 (or some other wall). Male adaptor 25A is held in place by internal nut or fastener 26 screwed to abut the inside surface of wall 14, and a gasket 27 is located between nut portion 25B and the external surface of wall 14.

Drain pan 10 is formed by folding of a blank 40 as shown by the fictitious fold lines shown in FIG. 8. Drain pan 10 is not crimped, meaning it does not have corrugated surfaces. Preferably the blank is made from steel and usually is made of sheet metal. An appropriate thickness is 0.0193 inches. However, other materials that create a rigid, leak proof drain pan when folded can also be used. The sheet metal is cut to the desired blank size. The dotted lines shown in FIG. 8 display where blank 40 is folded to create drain pan 10 in FIG. 1. Each section separated by the dotted lines substantially corresponds to the parts of drain pan 10 as described above. Bottom wall 12 is substantially square-shaped although it is not limited to this embodiment as mentioned above. Blank 40 also includes front wall 14, rear wall 16 and side walls 18. A drain plug hole 30 is punched out of front wall 14 to accommodate drain plug 24. Drain plug hole 30 can be also located in rear wall 16 or side walls 18. Of course, more than one drain plug hole 30 can be punched to accommodate multiple drain plugs 24. Top edges 22 are also part of blank 40 and are located on each front wall 14, rear wall 16 and side walls 18 respectively. Top edge portions 22A, 22B and 22C are slightly chamfered at each end to allow for clearance when folded over at each corner section 20. Of course it is possible that top edge portions 22A, 22B and 22C are not chamfered at all or may be rounded. Top edge portions 22A, 22B and 22C do not have to be included in drain pan 10, but they are rendered smooth as discussed below to prevent them from cutting a person or items during handling and use, and to prevent them from scratching other drain pans during stacking.

Corner sections 20 are further defined as seen in FIGS. 4 and 5. Corner section 20 includes an outside corner 28 and an inside corner 29. FIG. 4 shows a magnified corner section 20 in more detail. Corner section 20 has four sides as defined by lines A and B, and phantom lines C and D. As seen in FIG. 4, a phantom line H diagonally bisects corner section 20 from outside corner 28 to inside corner 29 creating a top corner section 28A and bottom internal corner section 29A which are substantially the same size. An angle a is the angle between line B and phantom line D. α is also the angle between line A and phantom line C. As shown in FIG. 4, a is about 95 degrees. However, α is not limited to being 95 degrees and can either be an acute, obtuse or a right angle. As shown in FIG. 8, the edges between front wall 14 and rear wall 16, and bottom wall 12 are shown by phantom lines E and F, respectively. The edges between side walls 18 and bottom wall 12 are shown by phantom lines G.

FIGS. 5, 6 and 7 show the folding of corner section 20 as well as front wall 14, side wall 18 and top edge portions 22A, 22B and 22C. First, considering drain pan 10 in an unfolded condition and initially in a ground engaging position as shown in FIG. 8, the portion of sheet metal including phantom line H is forced upward from bottom wall 12 by hand or suitable machine, rotating top corner section 28A about bottom internal corner section 29A. Outside corner 28 is thus moved upwardly and inward as shown by arrow X towards bottom wall 12. At the same time, side wall 18 and front wall 14 are forced to fold inwardly as shown by arrows Y and Z respectively, about edges. Since top edges 22C and 22A are attached to side walls 18 and front wall 14, respectively, they too are pulled inward. However, top edges 22 are not yet folded over. When side walls 18 and front wall 14 become substantially perpendicular to bottom wall 12, top corner section 28A and bottom internal corner section 29A should be substantially coplanar. That is, lines A and B should be collinear and lines C and D should be collinear. Next, corner section 20 is folded either towards side wall 18 or front wall 14. In FIG. 6, corner section 20 is folded towards side wall 18 until it is substantially coplanar with side wall 18.

Next, top edge 22A of front wall 14 is folded inward at 180 degrees along phantom line I as seen in FIG. 6. FIGS. 4 and 5 show phantom line I before folding. The folding over of top edge 22A is for safety and prevents any sharp surfaces of blank 40 from cutting or injuring a user when handling drain pan 10. This same folding procedure is repeated for the other three corner sections 20. Finally, each top edge 22C of each side wall 18, as shown in FIG. 6, is folded inward at 180 degrees along dotted line L. Arrow J shows part of top edge 22 folding over part of corner section 20 to the position shown in FIG. 7. Arrow K shows the remaining part of top edge 22C folding over part of side wall 18. It is important that these top edges 20C are folded last, since they help secure corner sections 20 and prevent them from unfolding at each corner of drain pan 10. After the folding is complete, drain fitting 24 is inserted into drain hole 30 and is hermetically sealed by means of nut 25B and gasket 27 as explained earlier. Drain pan 10, which was created from blank 40, is now seamless and leak proof. No sealing around the corners or any part of drain pan 10 is necessary. Furthermore, no press, die or tooling was needed to create drain pan 10. Thus, drain pan 10 is relatively inexpensive to manufacture and creates significant cost savings compared to the previous drain pans created from a press.

After multiple drain pans 10 of the same size have been manufactured, they can be stacked as seen in FIG. 9 for storage purposes in the semi-stackable arrangement to reduce the space on the shelves of wholesalers or for shipment. The stacking configuration shown in FIG. 9 allow for twice the number of drain pans 10 to be stacked compared to the prior art drain pans as seen stacked in FIG. 10.

Having described the invention, it will be apparent to those skilled in the art that alterations and modifications may be made without departing from the spirit and scope of the invention limited only by the appended claims.

Claims

1. A seamless drain pan for collecting and storing a liquid such as condensate and the like, said drain pan comprising:

a bottom wall;

a front wall having a top edge portion, said front wall being integral with and substantially perpendicular to said bottom wall;

a rear wall having a top edge portion, said rear wall being integral with and substantially perpendicular to said bottom wall;

a first side wall having a top edge portion, said first side wall being integral with and substantially perpendicular to said bottom wall, said first side wall being connected to said front wall at a first leak proof front intersection and said first side wall being connected to said rear wall at a first leak proof rear intersection;

a second side wall having a top edge portion, said second side wall being integral with and substantially perpendicular to said bottom wall, said second side wall being connected to said front wall at a second leak proof front intersection and said first side wall being connected to said rear wall at a second leak proof rear intersection;

said front wall, said rear wall, said first side wall and said second sidewall having a cross section in the shape of a rectangle; and

a corner section disposed at each of said leak proof front intersections and each of said leak proof rear intersections, each corner section having an outside corner and an inside corner, said outside corner and said inside corner being disposed wherein a fictitious bisecting line connecting said outside corner and said inside corner bisects each of said corner sections, wherein each corner section further comprises: a top corner section integral with one of said first side wall and said second side wall; a bottom corner section integral with one of said front wall and said rear wall; said top corner section and said bottom corner section intersecting at said fictitious bisecting line of each said corner section; wherein each corner section comprises said top corner section and said bottom corner section folded one over the other along said fictitious bisecting line, said top corner section and said bottom corner section being substantially coplanar and lying parallel to a selected one of said first side wall, said second side wall, said front wall and said rear wall.

2. A seamless drain pan for collecting and storing a liquid such as condensate and the like, said drain pan comprising:

a bottom wall;

a front wall having a top edge portion, said front wall being integral with and substantially perpendicular to said bottom wall;

a rear wall having a top edge portion, said rear wall being integral with and substantially perpendicular to said bottom wall;

at least one side wall having a top edge portion, said at least one side wall being integral with and substantially perpendicular to said bottom wall, said at least one side wall being connected to one of said front wall and said rear wall at a leak proof intersection; and

a corner section disposed at said leak proof intersection, said corner section having an outside corner and an inside corner, said outside corner and said inside corner being disposed wherein a fictitious bisecting line connecting said outside corner and said inside corner bisects said corner section, wherein said corner section further comprises: a top corner section integral with said at least one side wall; a bottom corner section integral with one of said front wall and said rear wall; said top corner section and said bottom corner section intersecting at said fictitious bisecting line of said corner section; wherein said corner section comprises said top corner section and said bottom corner section folded one over the other along said fictitious bisecting line, said top corner section and said bottom corner section being substantially coplanar and lying parallel to a selected one of said at least one side wall or one of said front wall and said rear wall.

3. A seamless drain pan according to claim 2, wherein said respective top edge portions of said walls are folded over the respective corner sections to prevent unfolding of the respective corner sections.

4. A seamless drain pan according to claim 2, wherein said drain pan has a cross section extending through said front wall, said rear wall and said at least one side wall, said cross section being in the shape of a rectangle.

5. A seamless drain pan according to claim 2, wherein said drain pan is manufactured from sheet metal.

6. A seamless drain pan according to claim 5, wherein said sheet metal has a thickness of approximately 0.0193 inches.

7. A seamless drain pan according to claim 2, further comprising a drain fitting located on the outside of at least one of said front wall, rear wall or at least one side wall to drain liquid from said drain pan.

8. A seamless drain pan according to claim 7, each of said walls having an inside surface and an outside surface, said drain fitting comprising:

a nut portion having an externally threaded tubular portion extending through one of said walls;

a male adaptor extending from said nut portion;

a gasket located between said nut portion and the external surface of said one of said walls; and

a fastener screwed on said nut portion for abutting the inside surface of said one of said walls.

9. A seamless drain pan for collecting and storing a liquid such as condensate and the like, said drain pan comprising:

a bottom wall;

a front wall having a top edge portion, said front wall being operatively connected to said bottom wall at a leak proof front intersection;

at least one side wall having a top edge portion, said at least one side wall being operatively connected to said bottom wall at at least one leak proof side intersection, said at least one side wall being connected to said front wall at a respective juncture of said leak proof front intersection and said at least one leak proof side intersection; and

at least one corner section disposed at said respective juncture, each corner section having an outside corner and an inside corner, said outside corner and said inside corner being disposed wherein a fictitious bisecting line connecting said outside corner and said inside corner, bisects said respective corner sections, said at least one corner section further including: a top corner section operatively connected to said at least one side wall; a bottom corner section operatively connected to said front wall; and said top corner section and said bottom corner section intersecting at said fictitious bisecting line of said at least one corner section; wherein said at least one corner section comprises said top corner section and said bottom corner section at least partially folded one over the other along said fictitious bisecting line.

10. A process of making a seamless drain pan for collecting liquid, the drain pan having a front wall, a rear wall, opposing side walls connecting the front wall and the rear wall, and a bottom wall connected to a corresponding edge of each of said walls, said process comprising the following steps:

cutting a metal sheet in a generally flat rectangular form, with each side having a top edge portion extending from the respective side and being shorter than the respective side, each top edge portion having opposing ends transverse to the respective side and intersecting the respective side at a juncture, and adjacent sides forming outside corners, fictitious first and second lines extending from the respective junctures of the adjacent edges to an inside corner point to form a first angle, with a fictitious third line extending from the respective outside corners of the rectangular sheet to the respective inside corner points to bisect the first angle;

folding the respective outside corners using the respective inside corner point as the respective pivots, and further commencing the folding of the respective opposing side walls, the front wall and the rear wall about lines extending between adjacent inside corner points, until the respective side walls, front wall and rear wall are generally perpendicular to the unfolded part of the metal sheet, the unfolded part being the bottom wall, the respective halves of the respective outside corners being doubled over to form a doubled over corner section with the first and second fictitious lines being adjacent each other with the confines of the adjacent side wall and the adjacent front or rear wall; and

folding the respective doubled over corner sections against the adjacent side wall or adjacent front or rear wall.

11. The process of making a seamless drain pan according to claim 10, and further including the step of folding the respective top edge portions so that they are adjacent to the respective side walls, front wall and rear wall.