Fill Funnel Construction For Plastic Tubs

Abstract

The fill opening extending through a sidewall of a plastic dishwasher tub is sealed with respect to an interconnecting fill funnel while splash-out and spray-out through the fill funnel are substantially eliminated. The fill funnel comprises a unipartite, plastic construction which is secured to the exterior surface of a plastic tub sidewall by fasteners extending through the funnel and into mounting bosses on the tub wall but terminating short of the inner tub surface to eliminate any fastener sealing requirement. The fill funnel includes a short, cylindrical conduit extending through the fill opening which includes an integral, diametral rib whose lower horizontal surface lies within the normal splash-out and spray-out paths intersecting the fill opening.

Description

BACKGROUND OF THE INVENTION

The invention is directed to large capacity front loading dishwashers of the type normally comprising a permanent installation and employing upper and lower dish supporting racks as opposed to the smaller, low capacity, portable and/or top loading dishwashers. The reason for the distinction is that the ultimate objective of the invention is the employment of a unipartite plastic tub in large capacity, front loading dishwashers and while some of the problems presented by a proposed use of such a tub would be common to dishwashers of either type; the majority are distinct. Typical distinctions relate to increasing wall flexibility with increasing area, the absence of encompassing metal housings, greater tub shape complexity and additional interior tub mountings such as dual rack support structures. Accordingly, the ensuing background discussion relates primarily to front loading dishwashers of the type normally adapted for a permanent, under cabinet, installation.

The high temperature, corrosive environment to which automatic dishwasher chambers are subjected dictates that the surfaces of those internal components in contact with such environment be either highly resistant, or immune, to corrosion. Corrosion resistant metals such as stainless steel represent a substantial cost factor in this highly competitive appliance field and the long term industry trend has been toward the use of inert materials to resist the corrosive effects of the chamber environment which are magnified adjacent the usual metal tub seam welds. Insofar as the tub itself, representing the far greater internal surface area exposure, is concerned; the general trend in the United States has been toward the application of an adherent plastic coating to the tub interior while European manufacturers have gone more to the use of plastic tub liners. In either event, the basic structural and design parameters that have prevailed since the advent of the modern front loading automatic dishwasher remained valid. This for the reason that overall dishwasher design parameters, both as regards utility and structural integrity, are virtually unaffected by whether the conventional metal tub is coated, lined or exposed.

Conceptually, the use of a unipartite plastic dishwasher tub, i.e., one not requiring a more rigid backing or outer support structure, represents a substantial advance in the art. Exemplary are the greatly decreased cost factors of a molded plastic tub vis-a-vis that of a metal tub requiring a further coating or lining operation; reduction in finishing labor requirements and particularly tub welding operations; longer tub life due to corrosion resistance which is independent of faulty coating procedures or chipping; decreased thermal and acoustical transmission thus minimizing need for separate insulation; and a lesser inventory requirement for separable components susceptible of integral molding with the tub.

The reduction to practice of such a concept, as applied to front loading dishwashers on an assembly line basis, however, present a myriad of problems which arise as a requirement for different approaches to those engineering considerations which had previously been predicted upon the use of a metal tub. The distinctions are primarily those associated with material strength, the unusually high temperature environment to which the tub is subjected and considerations relating to plastic molding procedures.

The advantages of the fill funnel disclosed herein as regards the elimination of splash-out and spray-out during a wash cycle are applicable to any dishwasher construction while the specific mounting of the same in such manner as to eliminate potential leakage paths adjacent the securing fasteners and take advantage of an integrally molded fastening component is a function of the combination of such fill funnel with a plastic tub.

SUMMARY OF THE INVENTION

Splash-out and spray-out, i.e., that movement of wash liquid from the wash chamber back into the fill funnel as a function of wash liquid agitation and spray during a normal wash cycle, is virtually eliminated by the presence of a horizontal rib spanning the fill opening whose undersurface is positioned to intersect that path of liquid splash and/or spray directed into the fill opening.

A plurality of outstanding bosses are molded integrally with an exterior plastic tub sidewall and the fill funnel is provided with coacting mounting sockets receiving the mounting bosses. The use of separable fasteners which extend through the fill funnel and into the mounting bosses to terminate short of the interior tub wall not only retains the imperforate character of the tub wall surrounding the fill opening but also eliminates the need for coacting fasteners and/or seals on the interior tub wall surface to retain the fasteners.

DESCRIPTION OF THE DRAWING

FIG. 1 is a front perspective view of a front loading dishwasher employing the fill funnel of the present invention;

FIG. 2 is an elevation depiction of the fill funnel as viewed from the left side of FIG. 1;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2 illustrating the mounting of the fill funnel to the tub wall; and

FIG. 4 is a front elevation of the fill funnel as viewed from the front of the dishwasher of FIG. 1 with the tub sidewall being shown in section.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 is illustrated a front loading dishwasher 10 having a plastic tub 12 whose sidewall 14 includes a fill opening 16 (FIG. 3) located above the normal wash cycle water level and spray bar 18. As will be apparent from FIGS. 3 and 4; that portion of tub wall 14 surrounding fill opening 16 and comprising the fill funnel mounting area is imperforate thus eliminating the usual potential leakage path associated with conventional fastening structures. Fill funnel 20, comprising a unipartite plastic molding, is mounted to tub wall 14 through the intermediary of plastic bosses 22 molded integrally with tub wall 14, mounting sockets 24 on fill funnel 20 and separable fasteners 26. The funnel mounting bosses are preferably preformed with blind fastener receiving bores terminating short of the inner surface 28 of tub wall 14 which are threaded by introduction of a screw fastener. Alternatively, the bosses could be solid preforms which are tapped by the introduction of fasteners 26. The end walls 30 of the fill funnel mounting sockets are normally preformed with fastener receiving openings which aid in the alignment and guidance of fasteners during a power driven operation to thread or tap the plastic bosses which operation obviates the necessity for additional separable sealing and retaining elements such as conventional seals, lockwashers and nuts.

The fill funnel, itself, includes an integral, semi-cylindrical connector 32 upstanding from and in open communication with the hollow interior 34 of the funnel body which terminates in a perpendicularly related cylindrical conduit portion 36 sized to extend through tub wall fill opening 16 with the truncated, open end 38 thereof lying substantially in the plane of inner tub wall surface 28. An integral, horizontal diametral rib 40 spans the open end of conduit section 36 to block or deflect at least a major fraction of that upward liquid flow path indicated by solid arrows 42 in FIG. 3. The generally straight line flow path illustrated in FIG. 3 is more accurately representative of the upward flow path emanating from the spray bar and commonly known as spray-out due to its tendency to exit from the open upper side 44 and end of the fill funnel which comprise the necessary vent or anti-siphon opening. The splash action occuring during a normal wash cycle may be thought of as having a mean free path in the vicinity of the fill opening which approximates the illustrated flow path 42. In either event, that portion of such flow path as would normally gain access to the open end of conduit 36 and impinge upon the interior back wall of the funnel at an acute angle for upward defection is blocked by the lower surface of rib 40 as indicated in FIG. 3.

Connector 32 is adapted for connection with a supply conduit 46 and its semi-cylindrical shape is simply to facilitate one piece molding of the fill funnel.

Fill opening 16 is sealed by a seal 48 received within an annular recess defined between conduit portion 36 and a surrounding, concentric rib 50.

In operation, wash water from supply conduit 46 enters the wash chamber via conduit portion 36 and reverse flow through the fill funnel, as under the impetus of splash or spray from a normal washing operation, is substantially precluded by the presence of rib 40 lying within the normal splash-out/spray-out flow path.

While the background discussion of this specification is related primarily to front-loading dishwashers of the type normally adapted for a permanent undercounter installation as opposed to the type of dishwasher having a hinged top closure for top-loading, it should be emphasized that many such machines are commercially produced and purchased for indefinite use as a free-standing model adaptable at a later time by the owner to a built-in unit beneath a kitchen countertop to blend with the matching cabinet structure of the kitchen. Generally, the difference between the unit designed as a "convertible" and the unit to be immediately permanently installed is the inclusion of side, rear and top cabinet appearance panels to the basic unit structure as designed for permanent installation. Therefore, it should be understood that the present invention is specifically directed to the front-loading type of dishwasher structure whether of the generally lower-cost unit having no appearance cabinet enclosure or the more elaborate, temporarily portable unit designed for later modification for use in a fixed location.

Claims

I claim:

1. A dishwasher including a unipartite tub defining a wash chamber said tub having a fill opening in a sidewall thereof and bosses integral with said tub and spaced from said fill opening; spray means contained within said tub positioned below the level of said fill opening said spray means introducing an upwardly directed liquid spray path intersecting said fill opening at an acute angle relative to said sidewall; a door adapted to close said tub, said door having a generally vertically closed position; a fill funnel mounted on an exterior surface of said tub in flow communication with said fill opening to admit water to said wash chamber, said fill funnel including mounting sockets receivable by said bosses of said tub and baffle means positioned within the confines of said fill opening in intersection relation to said spray path.

2. The dishwasher of claim 1 wherein said fill funnel additionally includes a liquid flow conduit extending through said fill opening to terminate in a truncated open end lying substantially in the plane of said sidewall inner surface; and said baffle means comprising a horizontally disposed rib integral with said liquid flow conduit.

3. The dishwasher of claim 2 wherein the lower surface of said rib lies within said spray path for deflecting a major fraction of the upwardly directed liquid spray entering the open end of said conduit.

4. The combination of claim 3 including seal means surrounding said fill opening and in sealing engagement with said exterior tub wall surface and the fill funnel.

5. The combination of claim 4 wherein said fill funnel is of unipartite plastic construction.