Improved dual push door-lock device

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Solution Overview

Problem

Existing push-push door-lock devices cannot lock the door when a washing machine is operating, which is a critical safety requirement for household appliances like washing machines.

Innovation Solution

A dual push door-lock device with a containment casing, a closing assembly featuring a rotary hook and a blocking assembly, and a safety pin that interferes with the blocking assembly to prevent door opening during operation, allowing disengagement under a preset threshold force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a push-push door-lock device is used for easy opening, then ease of operation is improved, but the ability to lock the door during operation is lost

Engineering Contradiction:
Improveease of door openingVSAvoiddoor locking capability during operation
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The door-lock device is divided into separate functional modules: a closing assembly with rotary hook for push-push operation, and a blocking assembly with blocking lever and blocking member for locking capability. This segmentation allows each module to perform its specific function independently while working together to resolve the contradiction between ease of opening and secure locking during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blocking lever acts as an intermediary element between the blocking member and the rotary hook. It transmits the blocking action from the blocking member to the rotary hook, preventing the rotary hook from disengaging when the door is pulled during operation, thus enabling secure locking while maintaining the push-push opening mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If a blocking mechanism is added to lock the door during operation, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improvedoor locking capability during operationVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The blocking assembly is integrated within the same containment casing as the closing assembly, sharing common structural elements like the support and spring mechanisms. The blocking lever connects both the blocking member and the rotary hook, merging the locking function with the existing door-lock structure rather than adding a completely separate system, thus limiting the increase in complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring mechanism serves multiple functions: it provides the restoring force for the rotary hook during normal push-push operation and simultaneously provides the restoring force for the blocking lever during locking operation. This multi-functionality reduces the need for separate spring components, thereby limiting complexity increase while achieving reliable locking.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3312333B1Improved dual push door-lock device
Publication Date: 2019.05.15 BITRON SPA
  • EP3312333B1 patent drawingFigure 1~3
  • EP3312333B1 patent drawingFigure 4
  • EP3312333B1 patent drawingFigure 5a~5e

AI summary

The present invention concerns a door-lock device (1) for locking a door of a household appliance, such as a washing machine and the like, said door being of the type comprising a lug (N), said device (1) comprising a containment casing (2), having an opening, in which said lug (N) is insertable, a closing assembly (3), arranged within said containment casing (2), comprising a retaining member (33) intended to engage with said lug (N), such that when said lug (N) is pushed towards said retaining member (33), said retaining member (33) retains said lug (N), and when said lug (N) is then pushed toward said retaining member (33), said retaining member (33) free said lug (N), an blocking assembly (4) arranged in said containment casing (2), said blocking assembly (4) interfering with said retaining member (33), so as to allow in turn said lug (N) to disengage, when engaged, from said retaining member (33) due to a traction of said retaining member (33) over a presettable threshold, and a safety pin (51), movable between a retracted position, in which said household appliance is not operating, and an extracted position, in which said household appliance operates and said safety pin (51) interfering with said blocking assembly, so as to block said lug (N) and thus keeping said door closed.