Integral Dishwasher Tub Hinge Support for Precise Door Sealing

Solution Overview

Problem

Conventional automated dishwasher door connection mechanisms suffer from additive tolerances in tub-to-frame and frame-to-hinge plate positioning, leading to door wobble and poor sealing due to inaccurate pivot axis location.

Innovation Solution

The integration of a hinge support member molded with the tub, featuring bosses with precise bores, and self-tapping screws that secure hinge plates, providing a direct and accurate pivotal connection between the door and tub, reducing variability and enhancing alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a pair of hinge plates are affixed to the frame with hinge pins engaged in apertures, then the door can pivot about a horizontal pivot axis, but additive tolerances in tub-to-frame and frame-to-hinge plate positioning lead to unacceptably large variability in door location and pivot axis position

Engineering Contradiction:

Improvedoor pivoting capabilityVSAvoiddoor location and pivot axis position accuracy

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent merges the hinge support function directly into the tub structure by integrally molding the hinge support member with the tub. This eliminates the separate frame and hinge plate components, thereby removing the additive tolerances that occur when multiple parts are assembled together. The hinge pins are directly engaged in apertures formed in the integrally molded hinge support member, ensuring precise and consistent door positioning without the cumulative positioning errors from multiple assembly steps.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If hinge plates are secured to the frame, then the door can be connected to the dishwasher structure, but the accumulated tolerances result in door looseness and wobble

Engineering Contradiction:

Improvedoor connection stabilityVSAvoidpivot axis location consistency

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The hinge support member is integrally molded with the tub as a single unified structure, eliminating the separate frame and hinge plate components. This integration ensures that the pivot axis location is precisely controlled by the molding process rather than by cumulative assembly tolerances. The hinge pins are directly engaged in apertures formed in the integrally molded hinge support member, ensuring precise and consistent door positioning without the cumulative positioning errors from multiple assembly steps.

Inventive Principle:

Principle #5Merging (Combining)

3Ease of manufacture

If conventional hinge plates are used with additive tolerances, then the door can be assembled to the frame, but poor sealing between the door and tub occurs when the door is closed

Engineering Contradiction:

Improvedoor assembly simplicityVSAvoiddoor-to-tub alignment accuracy

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The hinge support member is integrally molded with the tub as a single unified structure, eliminating the separate frame and hinge plate components. This integration ensures that the pivot axis location is precisely controlled by the molding process rather than by cumulative assembly tolerances. The hinge pins are directly engaged in apertures formed in the integrally molded hinge support member, ensuring precise and consistent door positioning without the cumulative positioning errors from multiple assembly steps.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS8231738B2Dishwasher tub having integral hinge support member, and dishwasher incorporating same

Publication Date: 2012.07.31 ELECTROLUX CONSUMER PROD INC

AI summary

A dishwasher comprises a tub formed as a molded plastic structure having a bottom wall joined to a plurality of vertical walls, and a top wall joined to upper ends of the vertical walls, so as to define a wash chamber, a front side of the tub defining an opening for access to the wash chamber; (b) a door for closing the opening in the front side of the tub; (c) a hinge support member integrally molded with the tub and located proximate the front edge of the bottom wall of the tub; and (d) a pair of hinge plates respectively secured to the opposite side edges of the door and pivotally engaged with the hinge support member on the tub to enable the door to pivot relative to the tub about a horizontal pivot axis defined by the hinge support member.