Padlock Key Retention via Flexible Wiper Friction
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Solution Overview
Problem
Linear locks face issues with key retention due to counter-insertion biasing forces, causing the key to be forcibly ejected when the lock is not in use, as the existing key covers do not provide sufficient gripping strength to retain the key.
Innovation Solution
A padlock design featuring a cover with flexible wipers that extend from the sides of the keyhole, providing additional friction and gripping force to retain the key in place against outward ejection forces, and optionally made from polymer or elastomeric materials to enhance retention and prevent debris entry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a linear lock uses spring-biased tumblers to enable key insertion and rotation, then the locking mechanism can be reliably engaged and disengaged, but the springs create an outward ejection force that causes the key to be forcibly ejected from the keyway when not in use
Solution Approach 1:
A cover is introduced as an intermediary component between the keyway and the external environment. The cover includes a wiper that extends into the keyway to contact and retain the key, mediating between the ejection force from the tumblers and the need for key retention without altering the tumbler spring mechanism itself
2Object-affected harmful factors
If a traditional key cover is used to block debris entry into the keyway, then protection against contaminants is improved, but the cover lacks sufficient gripping strength to retain the key against outward ejection forces
Solution Approach 1:
The cover incorporates a flexible wiper made of elastomeric or polymeric material that can deform and apply continuous contact pressure against the key. This flexible element provides both sealing action to block debris and sufficient gripping force through friction to retain the key against spring ejection forces
Solution Approach 2:
The cover is constructed from composite or elastomeric materials that combine the properties of flexibility, friction, and sealing. These materials enable the cover to simultaneously provide debris protection and key retention through their inherent material characteristics
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 effectively retains the key within the lock, preventing ejection and ensuring secure key storage, while also inhibiting debris entry into the locking mechanism.
Implementation Method 1
The flexible wiper(s) can be configured to cover a portion of the keyhole before the key is inserted into the locking mechanism. The flexible wiper(s) may have a thickness selected to retain the key in the locking mechanism against the outward ejection force on the fully-inserted key. Alternatively or additionally, the surface(s) of the wiper(s) might be selected to provide additional frictional force to encourage retention of the key against the outward ejection force.
Data Source
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AI summary
A padlock configured to be locked and unlocked by a key includes a key-retaining cover. The padlock includes a lock body having an internal cavity with a locking mechanism received therein. The locking mechanism is a linear lock configured to receive the key through a keyhole to lock and unlock the padlock. A direction of insertion of the key into the locking mechanism is parallel with a direction of displacement of a plurality of tumblers in the locking mechanism thereby creating an outward ejection force on a fully-inserted key. The cover is disposed on the locking mechanism proximate the keyhole. The cover is configured to retain the key in position relative to the locking mechanism against the outward ejection force after the key is received in therein.