Screw-Latching Assembly With Built-In Overdrive Protection

The patent applies preliminary action by pre-configuring the screw with a specific unthreaded section length that corresponds to the threaded section length. This preliminary design ensures that when the screw is driven into the nut, the unthreaded section automatically engages with the nut's internal geometry at the correct depth, preventing overdrive before it can occur. The built-in collar further pre-positions the screw to ensure proper engagement depth.

The patent implements self-service through the self-limiting mechanism where the unthreaded section of the screw automatically engages with the nut's threaded bore. As the screw is driven in, the transition from threaded to unthreaded section creates a natural stop that prevents the screw from being overdriven. The system serves itself by using its own geometric features (unthreaded section, built-in collar) to enforce the correct installation depth without external control.

The patent eliminates the need for calibrated torque devices by implementing a self-limiting mechanical feature. The unthreaded section of the screw, when combined with the built-in collar, creates an automatic depth-stop mechanism that prevents overdrive without requiring specialized tools or calibrated equipment. The system uses its own geometric features to enforce proper installation parameters.

The patent replaces expensive calibrated torque devices with a simple geometric feature built into the screw itself. The unthreaded section and built-in collar are inexpensive manufacturing features that provide the same protective function as costly torque-controlled installation equipment, making the solution accessible and cost-effective.

The patent applies segmentation by dividing the screw into distinct functional sections: a threaded section for engagement and an unthreaded section for depth limitation. This segmentation allows the screw to be made longer for increased reach while the unthreaded section acts as an automatic depth-stop, preventing overdrive regardless of the overall screw length. The built-in collar further segments the structure to reinforce the depth-limiting function.

The patent uses preliminary action by pre-configuring the proportion between threaded and unthreaded sections during manufacturing. The unthreaded section is designed to be equal in length to the threaded section, creating a built-in depth reference that prevents overdrive. This preliminary geometric configuration ensures that longer screws automatically self-regulate their engagement depth.

The patent introduces a built-in collar as an intermediary element between the threaded and unthreaded sections. This collar serves as a mediator that provides a positive engagement feature for removal tools while the unthreaded section maintains overdrive protection. The collar's external geometry allows tool engagement, and its internal geometry provides a shoulder that the spring can bear against, facilitating controlled removal without compromising the depth-limiting function.

The patent applies dynamics through the spring mechanism that interacts with the built-in collar. During installation, the spring is compressed and stores energy. During removal, the spring expands and pushes the screw outward, assisting the removal process. This dynamic element compensates for the lack of threads on the unthreaded section, making removal easier without affecting the overdrive protection provided by the unthreaded geometry.