Retaining Pin Assembly Groove Retaining Ring Lifting System
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Solution Overview
Problem
Existing lifting systems require disengagement of retaining pins from lock arms for assembly and disassembly, which can be inconvenient and inefficient, especially when operating under various conditions.
Innovation Solution
A retaining pin assembly with grooves or slots on the shaft to hold a retaining ring, allowing the pin to be retracted without disengagement from the lock arm, enabling axial movement and secure locking with a retaining ring that can be withdrawn into a recess during assembly and disassembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the retaining pin is made removable for disassembly, then ease of disassembly is improved, but the risk of accidental disengagement during use increases
Solution Approach 1:
The retaining pin assembly is segmented into two functional parts: the retaining pin itself and the retaining ring. The retaining pin provides the primary locking function, while the retaining ring acts as a secondary safety element that prevents accidental disengagement. This segmentation allows the system to provide both easy disassembly (by removing only the retaining ring) and high reliability (through the dual-retention mechanism).
Solution Approach 2:
The retaining ring is pre-installed on the retaining pin in a nested configuration before assembly. This preliminary action ensures that when the retaining pin is inserted through the lock arm and hook cam, the retaining ring is already in position to prevent accidental removal. The grooves on the retaining pin shaft are also prepared in advance to receive and hold the retaining ring tabs.
2Reliability
If the retaining pin is fixed in place for security, then reliability is improved, but ease of disassembly deteriorates
Solution Approach 1:
The retention function is segmented into primary retention (retaining pin) and secondary retention (retaining ring). The retaining pin provides secure locking through its fixed position and engagement with the lock arm and hook cam. The retaining ring provides secondary security but is designed to be easily removable for disassembly. This segmentation allows the system to maintain secure locking while enabling easy disassembly by removing only the retaining ring.
Solution Approach 2:
The system transitions from a completely fixed retaining pin design to a dynamic assembly where the retaining ring can be easily removed or installed. The retaining ring's ability to slide along the grooves of the retaining pin shaft provides controlled movement: it remains secured during normal operation but can be quickly removed when disassembly is needed, making the system adaptable to different operational states.
3Reliability
If a cotter pin is used to secure the retaining pin, then reliability is improved, but device complexity increases
Solution Approach 1:
The retaining ring and retaining pin are merged into a single integrated assembly. The retaining ring is permanently attached to the retaining pin through the groove-tab mechanism, forming a unified component that performs both retention functions. This merging eliminates the need for separate cotter pins or other additional fastening elements, reducing the total number of components while maintaining reliable secure connection.
Solution Approach 2:
The retaining ring serves multiple functions: it prevents accidental disengagement of the retaining pin, provides a convenient removal mechanism for disassembly, and acts as a safety backup. This multi-functionality consolidates what would otherwise require multiple separate components (cotter pin, safety wire, etc.) into a single universal element, reducing device complexity while maintaining or improving reliability.
Data Source
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AI summary
A retaining pin assembly for a lifting system which includes a hook prong (32) and a hook cam (22). The retaining pin assembly includes at least one lock arm assembly (16) having a first end (20) with at least one aperture (26) which aligns with an opening through the hook cam and having an opposed second end (30) with at least one aperture (28) which aligns with an opening through the hook prong. A hook cam retaining pin (40) has a head (50) and has a shaft (52) passing through the hook cam opening and the lock arm first end aperture, wherein the shaft has at least one groove (60) therein parallel to the axis of the shaft. A retaining ring (62) surrounds the hook cam shaft, the retaining ring having at least one inwardly extending tab (64) received in the shaft groove in order to retain the pin in the lock arm. A recess in the lock arm receives the retaining ring therein.