Patent Application
20070119482
1. Field of the Invention
The present invention pertains to the art of dishwashers and, more particularly, to a seal provided on a lid of a drawer-type dishwasher for preventing washing fluid from escaping from a wash tub.
2. Discussion of the Prior Art
In general, dishwashers having pull-out drawers are known in the art. In some cases, the dishwasher will include an upper, pull-out drawer defining a wash tub for washing smaller objects such as glassware, utensils, small plates and the like, and a lower, conventional-type dishwasher for washing larger objects such as plates. In other cases, the dishwasher will include upper and lower pull-out wash tubs, or just simply be provided with a single pull-out type wash tub. In any event, the pull-out wash tub must include a lid having a water-tight seal to prevent washing fluid from leaking from the dishwasher during a washing operation.
In certain known prior art, the lid is pivotally mounted to the dishwasher above the pull-out wash tub. With this arrangement, the lid is elevated from the wash tub when the drawer is withdrawn from the dishwasher, and lowered onto the wash tub when the drawer is inserted back into the dishwasher. This design requires a seal or gasket to be provided either on the lid or about an upper portion of the wash tub.
In accordance with some arrangements, once the lid is positioned over the wash tub, a seal is inflated with air to ensure a proper, water tight fit. In general, this arrangement requires a compressor and tubing that are interconnected to the seal. If a failure occurs in any of these components, the overall seal will fail, allowing washing fluid to escape from the wash tub. In addition, as the inflatable seal is subjected to repeated operation in a somewhat harsh environment, over time the seal can become brittle and develop a leak.
Other arrangements employ a seal having a bellows or compression pad that is forced against an upper portion of the wash tub. In a manner similar to that described above, the compressive forces that are applied to the compression pad can eventually cause the seal to warp and possibly allow washing fluid to escape from the wash tub.
Regardless of the existence of seals in the prior art, there still exists a need for an improved sealing arrangement for a wash tub lid of a drawer-type dishwasher. More specifically, there exists a need for a sealing arrangement that is able to withstand repeated applications of compression force without allowing a substantial portion of the compression force to be transferred to a sealing surface, thereby enhancing the effective useful life of the sealing arrangement.
The present invention is directed to a drawer-type dishwasher incorporating a seal element that prevents washing fluid from escaping from a wash tub portion of the dishwasher. The dishwasher includes a frame assembly, a drawer which defines the wash tub and is slidably mounted in the frame assembly, and a lid member. The lid member is mounted so as to be lowered against the wash tub when the drawer is shifted into the frame assembly, and raised when the drawer is shifted out of the frame assembly. In accordance with the invention, the lid member is provided with a seal element that is urged against an upper edge portion of the wash tub when the lid is lowered.
In accordance with the most preferred embodiment of the invention, the seal element is secured about a peripheral edge of the lid member. Specifically, the seal element includes a base portion, a deflecting finger portion and a flat pad portion. The flat pad portion projects from the base portion to form a corner section, with the deflecting finger portion projecting at an angle therefrom. With this arrangement, when the seal element is urged against the wash tub, a compressive force is applied to the flat pad portion causing the deflecting finger to seal against the wash tub in a manner that shields the deflecting finger from most of the compressive force. Since the deflecting finger is shielded from the compressive force, the overall life of the seal is extended.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
With initial reference to
In accordance with the invention, upper unit or drawer 16 is shown to include a front wall 20, a rear wall 21, a bottom wall 22 and opposing side walls 23 and 24 that collectively define an upper wash tub 28. In addition, drawer 16 is provided with a decorative facade 29 that is secured to front wall 20. In a manner known in the art, upper wash tub 28 is provided with a dish rack 30 for supporting various objects, such as dishware, glassware, and the like to be exposed to a washing operation. Upper wash tub 28 is slidably supported within support frame 4 through a pair of extensible support guides, one of which is indicated at 33. With particular reference to
In accordance with the invention, lid assembly 35 includes an outer peripheral edge 36 that surrounds and defines a cover section 37. Lid assembly 35 is provided with a movable support mechanism 38 that is employed to raise and lower lid assembly 35 relative to wash tub 28. As the specific structure and operation of support mechanism 38 is not part of the invention, it will not be discussed further here. Instead, reference is made to co-assigned U.S. Pat. No. 6,491,049 entitled “Lid Construction for Drawer Dishwasher”, which issued Dec. 10, 2002, and co-owned U.S. Patent Application entitled “Latching and Sealing Mechanism for a Drawer-Type Dishwasher” filed on even date herewith, both of which are incorporated herein by reference. As further shown in
For the sake of completeness, lower washing unit 18 is provided with a door 50 for selectively closing a lower washing chamber 54. As shown, lower washing chamber 54 is provided with an upper spray arm 57 for directing washing liquid downward onto articles placed within lower washing chamber 54, as well as a lower spray arm 58 for directing washing liquid upward onto articles supported on a rack (not shown). Upper and lower spray arms 57 and 58 are supplied by respective conduits 60 and 61 that, along with supply conduit 45, are in fluid communication with a pump 64 that is driven by a motor 66. Finally, upper and lower washing units 16 and 18 are provided with respective drain portions (not shown) for returning washing liquid from upper wash tub 28 and lower wash chamber 54. In general, the structure set forth above with respect to dishwasher 2 is provided for a better understanding of the drawings and has only been described for the sake of completeness. Instead, the present invention is particularly directed to a seal 76 that extends about outer peripheral edge 36 of lid assembly 35 for preventing washing fluid from escaping out of wash tub 28 during a washing operation.
With particular reference to
In accordance with the most preferred form of the invention, outer peripheral edge 36 extends to a down-turned flange segment 95. Down-turned flange segment 95 extends about a perimeter (not separately labeled) of lid assembly 35. With this particular arrangement, when lid assembly 35 is moved to the lowered position, flat pad portion 82 of seal element 76 is forced against an upper peripheral lip or rim 98 of wash tub 28. Flat pad portion 82 is forced into engagement through application of a compressive force provided by support mechanism 38. As lid assembly 35 is fully engaged about wash tub 28, flat pad portion 82 compresses so as to allow deflecting finger portion 86 to seal against an angled or tapered portion 104 that leads from peripheral rim 98 to front wall 20 of upper washing unit 16 as shown in
In accordance with the most preferred form of the invention, the majority of the compressive force provided by support mechanism 38 is translated through flat pad portion 82 onto peripheral rim 98. Therefore, deflecting finger portion 86 engages with angled surface 104 with relatively little force. Actually, once lid assembly 35 is fully seated and flat pad portion 82 is fully compressed, deflecting finger portion 86 will deflect approximately 0.080 inches (2.03 mm). In order to achieve the proper deflection, seal element 76 is formed from a flexible, elastomeric material having a durometer value of approximately 0.25 lbf per linear inch. In this manner, continued operation, i.e., raising and lowering of lid assembly 35 onto upper peripheral edge 98, will not cause seal element 76 to degrade in any significant manner. That is, compression of flat pad portion 82 allows the overall lid assembly 35 to sit in a compressed state without excessive force being applied to deflecting finger portion 86.
Although described with reference to a preferred embodiment of the present invention, it should be readily apparent to one of ordinary skill in the art that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, while the material for the seal is described as having a particular durometer value, other materials that would achieve the desired functions set forth above would also be acceptable. In addition, the amount of deflection could vary without departing from the scope of the present invention so long as the deflection finger is substantially shielded from the compressive force applied to the lid member. In general, the invention is only intended to be limited by the scope of the following claims.
