BACKGROUND OF THE INVENTION Movable shelves in appliances and cabinets, such as in refrigerators are well known. Typically the shelves are formed from multiple components, including multiple materials in some instances. For example, U.S. Pat. No. 3,814,492 discloses a movable refrigerator shelf having side brackets66 which are secured by welding to asupport plate68. The use of a welding bead as a fastener to hold together two separate parts requires extra assembly labor and materials, and hence increases the cost of the shelf. U.S. Pat. No. 6,488,347 discloses a one piece molded plastic frame for a refrigerator shelf that is molded around a separate glass shelf panel. U.S. Pat. No. 6,105,233 discloses a refrigerator shelf formed from a plurality of separate sheet metal stampings that are connected and held together by welds and receive a tempered glass shelf that has an elastic seal secured to its peripheral edge. Many other examples show similar shelf constructions.
A drawback of these existing shelf constructions is that extra labor and materials are required when the shelf is constructed of multiple components, whether those components are made from identical or different materials. Extra assembly and handling steps, and use of separate fasteners, including welding of separate parts, increase the cost of the shelves.
It would be an advance in the art if there were provided a single piece, metal shelf that could be formed without the need for assembly or use of fasteners for separate parts.
SUMMARY OF THE INVENTION The present invention provides a single piece, metal shelf that may be formed without the need for assembly or use of fasteners to join or hold separate parts or components together.
In an embodiment, the invention comprises a shelf, usable in a refrigerator, which has a generally flat, horizontal support surface comprising a left edge, a right edge, a front edge and a rear edge. A first support arm extends along the left edge of the support surface and a second support arm extends along the right edge of the support surface. The first and second support arms are each connected by a substantially right angle bend to the support surface. The first and second support arms each extend rearwardly beyond the rear edge of the support surface. The support surface and the support arms are formed from a single piece of metal and are bent into a final configuration without the use of fasteners to join or hold separate parts or components together.
In an embodiment, the support surface includes a plurality of openings formed therein. For example, the plurality of openings may be a series of parallel slots extending generally front to rear. In one embodiment, the series of parallel slots may be two rows of parallel slots. In any configuration of openings, the openings may include downwardly depending walls which define the openings.
In an embodiment, the support arms each are provided with hooked tabs arranged to engage with a support ladder in the refrigerator.
In an embodiment, the support surface includes a raised rim extending around a perimeter of the surface.
In an embodiment, a downwardly extending lip may be formed at the front edge of the support surface.
In an embodiment, an upwardly extending ledge may be formed at the rear edge of the support surface.
BRIEF DESCRIPTION OF THE DRAWINGFIG. 1 is a perspective view of a refrigerator cabinet using a refrigerator shelf embodying the principles of the present invention.
FIG. 2 is a top perspective view of a stamped refrigerator shelf embodying the principles of the present invention.
FIG. 3 is a bottom perspective view of the stamped refrigerator shelf ofFIG. 2.
FIG. 4 is an enlarged bottom partial perspective view of the stamped refrigerator shelf ofFIG. 2.
FIG. 5 is a side sectional view taken generally along the line V-V ofFIG. 2
FIG. 6 is a side sectional view taken generally along the line VI-VI ofFIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention is directed to a shelf which finds utility as a refrigerator shelf, although it could be used in other environments, including use in other appliances, such as freezers and also in various cabinets and shelving applications. In order to illustrate an embodiment of the invention, the shelf is illustrated as a shelf that can be used in a refrigerator, however, its use should not be limited to such an environment.
FIG. 1 illustrates arefrigeration appliance20 having acabinet22 with adoor24 openable to expose arefrigeration compartment26. Other refrigeration appliances, such as some located in stores, do not have doors that need to be opened to expose the refrigeration compartment. Positioned within therefrigeration compartment26 are a number ofshelves28, one or more of which may embody the principles of the present invention. In the illustrated embodiment, theshelves28 are supported byslotted ladders30 at therear wall32 of therefrigeration compartment26 in a known cantilevered fashion.
Theshelves28 are shown in greater detail inFIGS. 2-6, where it is seen that each shelf has a generally flat,horizontal support surface34 comprising aleft edge36, aright edge38, afront edge40 and arear edge42. Afirst support arm44 extends along and depends from theleft edge36 of thesupport surface34 and asecond support arm46 extends along and depends from theright edge38 of the support surface. The first44 and second46 support arms are each connected by a substantiallyright angle bend48,50 to thesupport surface34 so that they each reside generally in a vertical plane. The first44 and second46 support arms each extend rearwardly and may extend beyond therear edge42 of thesupport surface34. Thesupport surface34 and thesupport arms44,46 are formed from a single piece of metal and are bent into a final configuration without the use of fasteners to hold separate pieces together. Thesingle piece shelf28 may be securely held in its folded final configuration or strengthened by a securing or strengthening element, such as by a metal clinch between two overlapping sections of the single piece shelf, or by a tack weld between two overlapping sections. Separate pieces are not required to be gripped and held in a predefined orientation relative to one another, rather the folded single piece must merely be retained in its folded condition temporarily while the securing or strengthening element is applied. In a progressive die press, the securing or strengthening element may be applied as an automated additional step without adding further complexity to the manufacturing process.
In an embodiment, thesupport surface34 includes a plurality ofopenings52 formed therein. For example, as shown inFIGS. 2 and 3, the plurality ofopenings52 may be a series of parallel slots extending generally front to rear. In one embodiment, as shown, the series of parallel slots may be two rows of parallel slots in which the slots are formed as elongated ovals. In other embodiments, the slots may have other configurations, such as extending side-to-side rather than front-to-rear, and may be arranged in chevron configurations or other non-linear configurations. Theopenings52 themselves may also be formed with a configuration different than the illustrated oval slot, and could include round, square, rectangular, pentagonal or other polygonal shapes and combinations of curved and straight edges.
In any configuration of openings, as shown in greater detail inFIG. 4, theopenings52 may include downwardly dependingwalls54 which define the openings. The downwardly dependingwalls54 provide additional strength to thesupport surface34. Alower edge55 of thewalls54 may be curled over to avoid sharp edges of the wall.
In an embodiment, thesupport arms44,46 each are provided with hookedtabs56 extending rearwardly of therear edge42 of thesupport surface34 and are arranged to engage with thesupport ladders30 in therefrigeration appliance20. Thetabs56 engage in the slots of theladders30 and arear edge58 of thesupport arms44,46 abuts against the ladders to support theshelf28 in a cantilevered fashion.
To provide additional strengthening for theshelf28, in an embodiment, thesupport surface34 includes a raisedrim60 extending around aperimeter62 of the surface. The raisedrim60 is comprised of a shortvertical wall segment64 and a horizontal wall segment66.
In an embodiment, a downwardly extendinglip68 may be formed at thefront edge40 of thesupport surface34 orrim60. Thislip68 extends across the entirefront edge40 and abuts the twosupport arms44,46. In some embodiments, thefront lip68 andsupport arms44,46 may be formed integrally, through appropriate bending and drawing operations, and in other embodiments, the front lip may be separate, but abutting the support arms.
In an embodiment, an upwardly positionedledge70 may be formed by arear edge riser72 at therear edge42 of thesupport surface34 orrim60. Theledge70 may extend across the entirerear edge42 of thesupport surface34 and a portion of thesupport arms44,46 may depend directly from the ledge. Also, the upperhooked tab56 may extend rearwardly from thesupport arms44,46 at the level of theledge70.
To provide further strengthening for theshelf28, one or more ribs orchannels74 may be provided in eachsupport arm44,46 extending generally in a front-to-rear direction.
Theshelf28, as described can be formed through a series of bends, draws and punches, and with the various strengthening bends and walls described allows the shelf to be formed from a thinner metal material than is presently used for refrigerator shelf construction. For example, presently used shelves have a thickness of about 0.060-0.070 inches, and the shelves made in accordance with the principles of the present invention may be formed of steel having a thickness of about 0.030 inches. In order to assure support strength for the attachment of theshelf28 to thesupport ladder30, the metal material forming the shelf may be folded over to provide a double thickness in the area of the tabs56 (as best seen inFIG. 5), either by folding the material up from a lower edge of thetabs56 or folding the material back from a rear edge of the tabs. If theshelf28 is formed from a material having sufficient thickness or strength, the folding over would not be necessary.
To form theshelf28 of the present invention, a single flat sheet of metal, such as cold rolled commercial quality steel, drawn quality cold rolled steel or stainless steel (300 series), may be sequentially operated on in a progressive die press in which various of theopenings52 are formed, the outer perimeter shape is defined by cutting or punching, the various bends and draws are made and thus the shelf is completed from a single flat sheet to the finished configuration by mechanical shaping, all without further assembly or use of fasteners including welding of separate components or parts. Tack welding or clinching of the folded or bent portions of the single piece shelf can occur, for strengthening or securing purposes, during the operation of the progressive die press, without the gripping or positioning of additional components or parts.
The resultingunitary self28 has the required structural strength while being very economical to manufacture. Following the formation of theshelf28 in the press, the shelf may be coated with powder coating, high solids coating, or electro-coating paint systems and may be pointed a variety of colors and/or may carry a variety of decorative hot stamps or films.
As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that we wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of our contribution to the art.