Research and development of this invention and Application have not been federally sponsored, and no rights are given under any Federal program.
Not Applicable
Field of the Invention
This invention relates to bi-fold tables, in general, and to improvements in their manufacture, in particular.
Description of the Related Art
As will be appreciated, bi-fold tables often find use as indoor-outdoor picnic party tables, especially for tailgating at outdoor sporting events. Also referred to as center folding tables, those typically available are composed of a medium density fiberboard with aluminum trim riveted at the edges rolling under and over the top surface of the board (with a further aluminum strip spanning across the top of each half section of the board where they meet, likewise riveted in place). One limitation of this table is that the fiberboard is not really rain or moisture proof, so that the table does not really become an all-weather product. Another limitation is that the fiberboard composition does not take a very good printed surface or other type graphics. When unfurled and opened, furthermore, a person sitting at the long side of the table finds that the aluminum strips on its top surface makes resting one's arms thereupon somewhat uncomfortable. Attempting to write on the table then becomes less than optimum, because of the raised bump of the aluminum strip. This further limits the use of the bi-fold table as a breakfast-in-bed table, and as a work table using a tablet or laptop.
Utilizing a blow molding process to fabricate a table of this sort, however, necessitates a molding of two separate half tables of double wall thickness each, between which an air pocket is formed—with this followed by a subsequent drilling of holes, the adding of a steel plate at their juncture, and a joining of the two halves together with rivets or nuts and bolts. And, because of the very nature of the air pocket fabrication, the printing or graphic impressioning on the top wall surface gives rise to restriction in the degree of force that can be applied in providing the impressioning on the top.
Moreover, such prior art constructions, by their very nature would cause added difficulties in trying to provide a storage box for toys or stationary on the underside of the tabletop, or a compartment for various uses (such as a built-in bluetooth speaker or WIFI router, etc.) as to do so, would require a drilling of at least one hole on the tabletop to be used as an affixing point in grasping the box underneath—thereby requiring a further “bump” on the tabletop surface as a stud would be needed with a cap to hold it in place. In particular for the case of a blow molded bi-fold top, a hole would need to be drilled to the lower wall and then once the box is joined, the box in and of itself would be in the way of closing—or, at the very best, sticking out. The usefulness of such storage box attached to the underside of the table, on the other hand, is obviously a desirable point in the making of a “play table” or a “learning table” where the educational items needed could be temporarily housed.
It is an object of the present invention, therefore, to provide a new and improved bi-fold table which overcomes the disadvantages of such prior art constructions.
It is another object of the invention to provide such a table which allows for an underneath attachment of storage compartments and/or releasable table legs.
It is an object of the invention, also, to provide a bi-fold table by a single molding process by which the manners of attaching the storage compartments and releasable table legs can be addressed at the same time.
It is yet a further object of the invention to provide such a bi-fold table at a lower manufacturing cost than with alternative fabrications.
The bi-fold table of the invention is manufactured of a hard thermosetting resin, preferably melamine formaldehyde (melamine). By employing heat curing in this manner, the prepolymer in the soft solid or viscous state is irreversibly changed into an infusible, insoluble polymer network, obviating any need for the addition of aluminum trim at the table's edges. In the same manner, integral connecting mechanisms of melamine are formed which are strong and without introducing problems of shrinkage—thereby eliminating the need for rivets or nuts and bolts to secure other trim of like appendages in place. In this respect, this does away with any aluminum trim or other bumps being provided at the edges of the table as the folding over of any aluminum trim is avoided. The need for the aluminum strips at the middle seam of the table halves is avoided as well—and because of the material employed, the tabletop becomes waterproof, harder, and able to be printed upon more easily.
As will further be seen, because of the injection molding production method of the invention, the underneath of the tabletop can be arranged to be “hollowed out”, with the side rim continued to be made of the same material in the same molding process so that the storage compartment and releasable legs can be emplaced without any occasion to stick out and be seen. As will be appreciated, this enables the bi-fold table to be used as a breakfast-in-bed table or as a lap table with the smooth top surface that can easily be printed upon. And as will become clear hereinafter, in a preferred embodiment of the invention, the connecting mechanism employed to join the halves together in opening or closing is able to be formed as part of the same injection molding as provides the tabletop as a solid core.
These and other features of the invention will be more clearly understood from a consideration of the following, taken in connection with the accompanying Drawings, in which:
Specifically:
In
With respect to the center-folding bi-fold table of the present invention, the tabletop 50 of the invention is composed of two halves 51, 52 formed by injection molding of a thermosetting resin cured by heat, preferably melamine formaldehyde (melamine) in which the thermosetting resin is usually liquid in malleable form prior to curing, and designed to be molded into the final form. The two halves 51, 52 are shown in
Hard left and right halves of the center folding bi-fold tabletop are thus fabricated by a melamine formaldehyde thermosetting resin injection molding as single solid cores which are waterproof and printable, with underside section ribs in a single process, requiring no side aluminum trim—and thus avoiding any drilling of holes in the sides and any scratching of the table edges in installing aluminum trim, and in a simpler installation process. As will become clear from the following, such injection molding process allows for the storage underneath the tabletop surface of the function box housings 60, the leg assemblies 55, the hinge struts 56, and any extension legs—with the result being that when closed, the bi-fold center folding table of the invention takes on the appearance as shown in
In accordance with the invention, the center folding bi-fold tabletop is thus formed of a pair of solid core halves formed through an injection molding process of a thermosetting resin, preferably of melamine formaldehyde. The tabletop halves so formed can be hinged together in several appropriate manners in controlling the opening and closing of the table. In accordance with the invention, furthermore, a preferred method of hinging is one formed through the injection molding process itself. As illustrated in
And, as
Pivots for rotating the leg assemblies 55 opened or closed are shown at 90 in
As thus described, the center folding bi-fold table of the invention becomes manufacturable as a single integral unit in an injection molded melamine process. A single-faced tabletop thereby becomes producible rather than one being “double walled” as with a blow mold process, and without the need for any aluminum wrapping as with medium density fiberboard constructions. A definite advantage that results in this manner is that “printing” can be done much easier to the tabletop as there is no protrusion of aluminum or similar metal on the top surface of the tabletop, and because the tabletop is composed of two hard core halves. With the top surface flat, silk screening also becomes available, and with the injection molding melamine process, the underside of the resulting tabletop becomes hollowed out with a side rim made of the same material in the same molding process. Likewise, the twist type clips and the locking channels can be formed as part of the molding process itself, finalized by a stamping of a metal plate or screw affixation to hold the leg assemblies, support struts, and storage boxes in position.
Whereas there have been described what are considered to be preferred embodiments of the present invention, it will be appreciated by those skilled in the art that modifications can be made without departing from the teachings herein. Thus, while the present invention is described in the context of a bi-fold, center folding table, its teachings of forming its sections through an injection molding process of a thermosetting resin—melamine formaldehyde—would apply equally as well to a fabrication where more than two sections are folded in forming the table, and/or where the sections formed are not of the same size, as with the preferably two sections being of a nature of equal “halves”. Similarly, while the description of the unit 60 is set forth as a “function box/storage compartment”, it will be apparent that that addition to the underside of the tabletop could serve as a built-in speaker music box, a bluetooth speaker, a WIFI router, or otherwise in fulfilling the applicability of the present invention to other uses. And, additionally, the described constructions even go further in providing the advantages of the invention to instances where stronger table designs might be required, in which event a further steel stamping, or like accessory can be employed, as by the plates 37, 39 of
A Provisional Patent Application covering the invention described herein was filed on Dec. 7, 2015, and assigned Ser. No. 62/263,977.
Number | Date | Country | |
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62263977 | Dec 2015 | US |