Panel fastener
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Solution Overview
Problem
Existing panel fastener cam and hook assemblies with ob-round cam holes are prone to spring disengagement, making them difficult to reset and leading to torque reduction over use, which complicates assembly and stability of insulated panels in refrigerated spaces.
Innovation Solution
A panel fastener design featuring a round cam engagement hole and a compressible spring that is pre-compressed before mounting, ensuring constant frictional contact and preventing spring dislodgment, along with a method of manufacturing that includes a tapering channel to compress the spring prior to positioning it within the cam's spring mounting notch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an ob-round cam hole design is used to allow spring insertion, then the spring can be positioned into the cam during assembly, but the spring may become dislodged when moved back to the spring recess position, and the cam can be rotated to release the hook
Solution Approach 1:
The spring is pre-compressed before insertion into the cam, ensuring it maintains constant contact with the cam's outer surface. This preliminary compression action prevents the spring from becoming dislodged during operation and eliminates the need for ob-round holes, as the pre-compressed spring naturally stays engaged with the round cam hole throughout the cam's rotation cycle
Solution Approach 2:
The invention changes the geometric parameters of the cam hole from ob-round to completely round, and modifies the spring compression state from relaxed to pre-compressed. This parameter change ensures the spring maintains constant frictional contact with the cam surface, preventing disengagement while allowing smooth rotation for hook actuation
2Force
If a C-shaped leaf spring operates in a clutch like action with an ob-round hole, then sufficiently high frictional resistance is provided for driving the hook, but the cam can be rotated under certain circumstances to release the hook
Solution Approach 1:
The spring is pre-compressed to maintain constant frictional contact with the round cam surface, providing sufficient driving force while preventing cam rotation that would release the hook. The round cam hole geometry combined with pre-compression ensures the spring remains engaged throughout the operational cycle
Solution Approach 2:
The spring is pre-compressed during assembly to establish constant contact pressure with the cam surface. This preliminary compression ensures the spring maintains adequate frictional resistance for hook driving while preventing unintended cam rotation and hook release during operation
3Ease of manufacture
If the spring is not pre-compressed before mounting, then assembly is simpler, but the spring may become dislodged when moved back to the spring recess position
Solution Approach 1:
The spring is pre-compressed before insertion into the cam, ensuring it maintains constant contact with the cam's outer surface. This preliminary compression action prevents the spring from becoming dislodged during operation, and the round cam hole design allows this pre-compressed spring to be easily inserted and retained
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 solution provides a more secure and stable fastening mechanism with consistent torque requirements, reducing the likelihood of panel shifting during assembly and eliminating the need for manual intervention to reset the fastener.
Implementation Method 1
contact between the spring and the hook round cam engagement hole causes frictional contact sufficient to rotate the hook through rotation of said cam
Implementation Method 2
a compressible spring that is pre-compressed before mounting, ensuring constant frictional contact and preventing spring dislodgment
Data Source
AI summary
A panel fasteners (20) is disclosed in the form of a hook and cam assembly (21) having two side walls (24) with a boss (27) through which a cam shaft (28) is journalled. The cam shaft has a socket (29) and a round cam (30). A hook (32) is frictionally mounted in camming engagement with the cam. A leaf clutch spring (33) is mounted within a spring mounting notch (36) and in frictional engagement with a substantially round cam engagement hole (34) of the hook. To position the spring into the spring mounting notch and cam engagement hole the spring is pre-compressed prior to mounting it within the spring mounting notch by forcing it through a narrowing channel positioned adjacent the cam.