Jet Intake Debris Fitting with Rotating Grill Bars
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Solution Overview
Problem
Outboard jet motors face issues with debris ingestion through the jet intake, leading to restricted water flow, cavitation, and potential motor damage, as existing protective fittings require manual cleaning and can be inefficient or cause alignment problems, especially when springs wear out.
Innovation Solution
A cable-operated debris protective fitting with stationary and movable grill bars, supported by a heel plate and cross pins, allows for remote operation from inside a jet boat, using a push-pull cable to rotate the grill bar assembly between open and closed positions, ensuring effective debris removal without stopping the boat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stationary grill bar assembly is used to protect the jet intake, then debris protection is improved, but the device requires manual cleaning and the boat must be stopped
Solution Approach 1:
The patent transforms the stationary grill bar assembly into a dynamic system by adding a rotatable grate bar assembly that can move between open and closed positions. This allows the protective fitting to adapt its state based on operational needs - closed for protection, open for cleaning - resolving the contradiction between maintaining debris protection and enabling easy cleaning operations.
Solution Approach 2:
The spring-biased rotatable grate bar assembly enables self-service operation where the operator can open the assembly from inside the boat using a lever, allowing debris to be cleared without external intervention or stopping the boat. The spring mechanism provides automatic closing force, reducing the effort needed for operation.
2Ease of operation
If a spring biased rotatable grate bar assembly is used, then cleaning operation is improved, but alignment problems occur and springs wear out
Solution Approach 1:
The patent introduces a cable-operated mechanism as an intermediary between the operator's lever action and the grate bar assembly. The cable transmits force through a heel plate to rotate the assembly, providing a more reliable and controllable connection than direct spring biasing. This intermediary mechanism maintains alignment and ensures consistent closing action without the wear problems of direct spring engagement.
3Ease of operation
If the grill bar assembly is made rotatable for easier cleaning, then cleaning accessibility is improved, but the mechanism becomes more complex
Solution Approach 1:
The patent divides the protective fitting into distinct functional segments: a stationary grill bar assembly for primary protection, a rotatable grate bar assembly for cleaning access, and a cable-operated mechanism for actuation. This segmentation allows each component to perform its specific function efficiently while keeping the overall system manageable and maintainable.
Data Source
AI summary
A debris protective fitting for a jet inlet of a outboard jet motor with stationary grill bars across the jet intake in front and rear slots with empty front slots provided between the stationary grill bars. Movable grill bars are supported across the jet intake in the empty front slots and a heel plate. The heel plate cups a rear of the jet intake and includes a center mounted stud for attachment of a push-pull cable for rotating the movable grill bars into alignment with the stationary grill bars forming a screen across the jet intake opening. As the movable grill bars are rotated away from the jet intake opening, the spacing between the bars in the screen is doubled causing rocks and other debris to be dislodged and fall out. Cleaning of the screen is thus accomplished without stopping the outboard jet motor or getting out of the jet boat.