Cam Lock Axial Movement Prevents Key Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Cam locks, such as those used in mailboxes and lockers, often allow the key to be accidentally pulled out when the cabinet is open, leading to potential loss and unintended cabinet openness, especially in environments like schools or swimming pools where children may play with the key.
Innovation Solution
A cam lock design featuring a lock cylinder with a shaft connected to a cam part, an outer bush ring, inner bush ring, and a spring, which keeps the cam part in a specific axial position when locked and allows it to move away from the cylinder when opened, preventing accidental key removal and ensuring the key can only be taken out when the cabinet door is closed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the cam part is allowed to move freely in axial direction when opened, then the key can be pulled out easily, but the key can be accidentally pulled out and lost
Solution Approach 1:
The cam part is designed to have dynamic axial movement capability when the lock is opened, allowing the cam to move away from the cylinder. However, when the lock is closed, the cam is constrained to its initial axial position by the inner bush ring, preventing accidental key removal while maintaining ease of intentional key removal.
Solution Approach 2:
The inner bush ring acts as an intermediary component that selectively constrains the cam part's axial movement. It allows movement when needed (opened state) while preventing movement when not needed (closed state), thereby resolving the contradiction between ease of operation and reliability.
2Reliability
If the cam part is constrained to keep key secure, then accidental key removal is prevented, but the key cannot be taken out when door is closed which is required functionality
Solution Approach 1:
The system dynamically changes the constraint state of the cam part based on the lock's operational state. When closed, the inner bush ring constrains the cam axially to secure the key. When opened, the cam can move axially away from the cylinder, enabling key removal. This dynamic behavior resolves the contradiction between security and operability.
Solution Approach 2:
The spring is pre-loaded to automatically push the cam part away from the lock cylinder when the key is inserted and the lock is opened, preparing the mechanism for key removal before the user even attempts to pull the key out.
3Reliability
If spring pushes cam part away from cylinder continuously, then key cannot be accidentally removed, but additional force is required to close the cabinet door
Solution Approach 1:
The spring exerts its pushing force periodically - actively pushing the cam away from the cylinder only when the lock is in the opened state. When the lock is closed, the cam returns to its initial axial position constrained by the inner bush ring, and the spring's force is not opposed. This periodic action pattern resolves the contradiction between key retention and door closing force.
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
Prevents accidental key removal and ensures the cabinet remains locked until intentionally opened and closed, reducing the likelihood of lost keys and unintended cabinet openness.
Implementation Method 1
a spring between the lock cylinder and the cam part, and around the shaft. The inner push ring covers the spring that is arranged to push the cam part away from the lock cylinder
Implementation Method 2
The spring is further arranged to turn the cam part at the first axial position towards the lock position
Data Source
AI summary
A cam lock has a lock cylinder and a cam part connected to the lock cylinder. The cam part is turnable from a lock position to an open position when turning a key placed in the lock cylinder. The cam part comprises a spring and a flange that is arranged to receive external force towards the lock cylinder. The spring allows the movement of the cam part at the open position towards the lock cylinder as response to external force. The spring is further arranged to turn the cam part towards the lock position.