Specialized Strand Lock Combines Combination Mechanism With Cable Bolt for Secure Cable Fastening

Standard cable locks offer either mechanical key security or dial combination access, but not both in a unified system. Bicycle and equipment thieves exploit this limitation by targeting visible locking mechanisms with specialized tools. This innovation combines rotating code rings with a preloaded latch mechanism that requires both correct code alignment and physical bolt insertion to unlock, creating a security checkpoint that defeats bypass attacks on either component alone.

The Problem

Personal property theft from vehicles, bicycles, and secured storage areas remains a significant urban problem. Thieves develop specialized knowledge about individual lock designs, using picks on mechanical locks or manipulating dial combinations through tactile feedback. Standard cable locks present a simple binary choice: mechanical security that can be bypassed with specialized tools, or combination security that can be bypassed with patient manipulation of code rings.

Users with expensive bicycles, e-bikes, and portable equipment need security that defeats both categories of attack. Traditional solutions require carrying two separate locks: a cable lock for convenient fastening plus a heavy U-lock for serious security. This forces an impractical choice between convenience and protection. Combination locks that appear modern and secure often employ weak designs that yield to sustained attack. Mechanical key locks require carrying physical keys that are easy to lose and difficult to remember.

What This Invention Does

The strand lock design features a lock body with dual closure components and a sophisticated locking mechanism oriented along a common lock axis. A bolt from the cable hoop can be introduced into the first closure part through a dedicated opening. The combination locking mechanism comprises rotating code rings and a preloaded latch mechanism that functions as both code protector and entry barrier.

When users attempt to unlock the device, the bolt must be inserted and physically pushed into the lock body. This insertion action urges the latch from its closed position into an unlocking position, but only if the code rings are set to the correct combination. The preloaded latch design means that without correct code alignment, inserting the bolt cannot move the latch, preventing unauthorized opening even if an attacker somehow extracts the bolt from the lock.

Conversely, someone knowing the combination but without access to the bolt cannot remove the cable because the actual bolt physically blocks opening. This dual-requirement approach means attackers must solve both the combination puzzle and physically manipulate the mechanical bolt – they cannot bypass one component by focusing on the other.

Key Features

• Dual Closure Parts. The lock body includes both a first and second closure section, creating layered security that requires proper alignment of multiple components.
• Combination Code Ring Array. Multiple rotatable rings position themselves in specific sequences. Only the correct combination allows the latch to reach unlocking position.
• Preloaded Latch Mechanism. A spring-loaded latch resists opening until code rings align to release it. The preload force prevents latch manipulation without correct code setting.
• Bolt Introduction Opening. The first closure part includes a precise opening that guides bolt insertion and prevents entry by foreign objects.
• Latch-Bolt Interaction. The latch releases a movement path for the bolt only when both conditions are met: correct code alignment and intentional bolt insertion.
• Secure Movement Path. Once the latch is urged into unlocking position, the bolt can complete its movement, releasing the cable from the lock body.
• Strand Hoop Integration. The cable bolt forms part of an integral strand hoop, ensuring the cable cannot be separated from the locking mechanism during transport or storage.

Who Is Behind It?

ABUS August Bremicker Söhne KG, a major German lock and security manufacturer with a century-long history, developed this advanced strand lock. Inventor Ernst Pankratius is credited with the design. The application claims priority from an earlier German patent application filed 27 August 2024. PHILLIPS ORMONDE FITZPATRICK in Melbourne provides Australian patent representation.

Why It Matters

Bicycle and e-bike theft has become a significant urban theft category as the value and convenience of electric bikes increases. Commuters need practical security that doesn’t require carrying heavy U-locks or managing multiple keys. This dual-mechanism approach provides professional-level security in a lightweight portable form factor that appeals to urban cyclists and equipment owners.

The design also interests fleet managers of bike-sharing and scooter-sharing services, where consistent security across multiple similar units prevents users from defeating lock designs through familiarity. The combination mechanism eliminates the key management complexity that municipal authorities face with hundreds of locked devices. Manufacturing innovations that reduce the cost of combination locking mechanisms could make this dual-protection approach mainstream, significantly improving anti-theft effectiveness without imposing expensive or inconvenient security measures on users.

Related Concepts

A combination lock uses a rotating dial or set of code rings to release a shackle without a physical key. While convenient, standalone combination locks are vulnerable to manipulation attacks – making hybrid designs that pair combination entry with a physical bolt more resistant to single-vector bypass.

Bicycle theft is a persistent urban problem that drives demand for stronger portable security. U-locks offer high cut resistance but poor convenience, while cable locks offer flexibility at lower security ratings – a gap that dual-mechanism designs aim to close without sacrificing portability.

---

AU 2025217354 was published in the Australian Official Journal of Patents on 19 March 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.