Fuel Nozzle Single-Handed Hold Open Trigger Mechanism
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Solution Overview
Problem
Current fuel dispensing nozzles with hold open mechanisms require a second hand to actuate, leading to operational inefficiencies and manufacturing variations that cause the mechanism to trip undesirably.
Innovation Solution
A fuel dispensing nozzle design featuring a trigger mechanism integrated into the hand lever, allowing the hold open function to be operated with the same hand, using a dual shaft assembly and spring-loaded components to maintain the flow position without needing continuous manual engagement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the latch member is located at the distal end of the lever with catches at the back of the hand guard, then the hold open mechanism can maintain fuel flow position, but a second hand is required to actuate the mechanism
Solution Approach 1:
The trigger is integrated into the hand lever as a single unified component rather than separate parts. The trigger is formed as an extension of the lever body, with the release button positioned on the lever itself, allowing the same hand that grips the lever to also actuate the hold open function.
2Reliability
If the latch member is positioned away from the user's hand, then the mechanism can engage catches securely, but manufacturing variations cause the mechanism to trip undesirably
Solution Approach 1:
The spring-loaded trigger mechanism automatically engages and disengages the latch member with the catches through a cam action. When the lever is squeezed, the trigger automatically releases the latch member, which then springs back into engagement with the next catch in the series, eliminating the need for precise manual positioning and compensating for manufacturing variations.
3Ease of operation
If the trigger mechanism uses spring-loaded components, then the hold open function can be actuated by the same hand, but the mechanism complexity increases
Solution Approach 1:
The spring-loaded trigger mechanism is integrated directly into the lever body as a unified assembly. The trigger is formed as part of the lever, with the spring and latch member positioned within the lever structure, minimizing the number of separate components and simplifying the overall mechanism while enabling single-handed operation.
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
Enables the user to maintain fuel flow without continuous hand operation, reducing operational errors and manufacturing-related issues by utilizing a spring-loaded trigger mechanism that engages with U-shaped catches, ensuring reliable and efficient fuel dispensing.
Implementation Method 1
The trigger mechanism includes a spring-loaded member that can be actuated by the user's finger to release the latch member from engagement with a catch
Data Source
AI summary
A fuel dispensing nozzle comprises a nozzle body defining a dispensing path extending between a distal inlet and a proximal outlet and configured to dispense fuel. A fuel flow valve is disposed in the nozzle body between the distal inlet and the proximal outlet. An actuation assembly movable to open the fuel flow valve is also provided. The nozzle also includes a shut-off mechanism operatively connected to the actuation assembly. A hand lever is pivotally connected with respect to the nozzle body, the hand lever being operatively connected to the actuation assembly so as to cause opening of the fuel flow valve when the hand lever is pivoted in a valve opening direction. The hand lever has a grasping portion extending between a proximal location nearer the proximal outlet and a distal location. The nozzle according to this aspect further includes a hold open mechanism including a trigger disposed at the proximal location of the hand lever. The trigger is pivotally connected to the hand lever and has an engaging element. A catch member is fixed with respect to the nozzle body and defines a plurality of catches corresponding to respective flow positions. The catches are each configured to receive the engaging element of the trigger.