Child-Resistant Trigger Sprayer Nozzle with Spring-Locked Indexing
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Solution Overview
Problem
Existing trigger sprayers lack a child-resistant mechanism that prevents accidental liquid discharge when the nozzle cap is rotated away from its off position, posing a risk of leakage and ingestion by children if the sprayer is inverted or tilted.
Innovation Solution
A child-resistant indexing nozzle assembly with a lock mechanism that requires two hands to rotate the nozzle cap from its off position, featuring a resilient spring and a finger pad that must be depressed to disengage the lock tab from a notch, ensuring the cap cannot be rotated without intentional action.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the nozzle cap is made rotatable to change discharge patterns (spray, stream, foam), then the adaptability of the sprayer is improved, but the risk of accidental liquid discharge by children increases
Solution Approach 1:
The lock mechanism applies a preliminary restraining force against the nozzle cap rotation through the spring-loaded lock tab that engages with the cam surface. This pre-applied counter-action prevents the harmful effect (accidental rotation) before it can occur, while still allowing the useful function (intentional rotation for pattern selection) when the finger pad is pressed to release the lock
2Object-affected harmful factors
If a lock mechanism is added to prevent child-resistant rotation, then safety against accidental discharge is improved, but the device complexity increases
Solution Approach 1:
The lock mechanism is merged with the existing indexing nozzle assembly components. The lock tab is integrated into the cap structure, the spring is housed within the nozzle body, and the cam surface is formed as part of the indexing mechanism. This merging approach provides child-resistant functionality without requiring a completely separate locking system, thus minimizing the increase in device complexity
Solution Approach 2:
The spring-loaded lock mechanism is self-actuating and automatically engages when the cap is rotated to the closed position. The cam surface automatically deflects the spring-loaded lock tab into the locked position, eliminating the need for separate actuators or complex control systems. The mechanism serves itself through the natural rotation motion of the cap
3Ease of operation
If the lock mechanism components are made visible, then the ease of operation is improved, but the aesthetic appearance deteriorates
Solution Approach 1:
The nozzle cap is designed with differentiated local qualities: the portion containing the finger pad opening is made transparent or translucent to reveal the lock mechanism components, while the其余 portions of the cap maintain an opaque, aesthetically pleasing appearance. This allows users to see and access the finger pad for operation while hiding the mechanical components from full view to preserve overall aesthetics
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The mechanism effectively prevents children from inadvertently rotating the nozzle cap, reducing the risk of liquid leakage and ingestion by requiring a deliberate two-handed operation to change the discharge mode, thus enhancing safety.
Implementation Method 1
the spring being bendable toward the orifice center axis in response to a radially directed external force acting on the spring
Data Source
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AI summary
An indexing nozzle assembly for a trigger sprayer has a manually rotatable cap mounted for rotation on a base of the nozzle assembly. Rotation of the cap relative to the base changes the nozzle assembly between an off condition where the nozzle assembly prevents liquid discharge from the trigger sprayer, and a combination of a spray condition, a stream condition, and/or a foam condition. The indexing nozzle assembly is provided with a child resistant feature in the form of a lock mechanism that prevents rotation of the nozzle cap relative to the nozzle base from the cap off condition position. The lock mechanism can be manually manipulated with one hand to disengage the lock mechanism, thereby permitting rotation of the nozzle cap from its off condition position relative to the base.