Lock Assembly With Handle-Blocked Fasteners Against Removal

The patent applies local quality by making the fastener holes accessible only in specific local areas (the recesses) rather than across the entire faceplate surface. The recesses are positioned such that they are accessible from the outside when the door is closed, allowing simple attachment, but are blocked from the inside when the bolt is engaged, preventing removal. This localized accessibility resolves the contradiction between ease of attachment and security against removal.

The patent extracts the security function from the complex mounting plate structure and integrates it directly into the lock case assembly housing. Instead of using a separate mounting plate with projections that require precise alignment and multiple attachment steps, the fastener holes are built into the housing itself with recesses that provide both security (by blocking internal access) and simplicity (by eliminating the need for alignment). This extraction of the security function resolves the contradiction between reliability and device complexity.

The patent applies inversion by reversing the conventional approach: instead of positioning fastener holes on the faceplate surface (which would prevent access when closed but require the door to be open for attachment), the fastener holes are positioned in recesses that are accessible from the outside when the door is closed. This inverted positioning allows attachment to be performed with the door closed, while still preventing access from the inside when the bolt is engaged, thus resolving the contradiction between reliability and ease of operation.