Derivative works — US Patent 11447993B1

As a Senior Patent Strategist and Research Engineer specializing in Defensive Publishing, I have analyzed US Patent 11447993B1 to generate a comprehensive "Defensive Disclosure" document. The objective is to proactively create prior art, rendering future incremental improvements by competitors obvious or non-novel, thereby strengthening the public domain and potentially discouraging further patenting in closely related areas.

Combination Prior Art Scenarios

Here are three scenarios combining US Patent 11447993B1 with existing open-source standards, demonstrating how the core functionalities could be integrated into broader systems:

Integration with Open-Source Smart Home Protocols (Matter/Zigbee): A derivative of the door security device (US11447993B1) incorporates miniature Hall effect sensors to detect the precise angular and vertical position of the locking swing plate (560) relative to the mounting plate (160), specifically confirming engagement within the locking channel (251) and clearance from the major rest (248). This sensor array also includes a passive infrared (PIR) motion sensor on the interior side of the locking swing plate to detect presence within the immediate vicinity of the door. An embedded, low-power microcontroller (e.g., ESP32-C3) collects this data and communicates wirelessly via a Matter or Zigbee module (e.g., Silicon Labs EFR32MG21) to a local smart home hub. This enables real-time remote monitoring of the door's security status (e.g., "Door locked," "Door unlocked and clear," "Forced entry attempt detected") through an open-source smart home application, allowing users to receive alerts or remotely verify the lock's state.
Integration with Open-Source Building Information Modeling (BIM) Standards (IFC): A digital representation of the door security device (US11447993B1) is developed in compliance with the Industry Foundation Classes (IFC) schema (ISO 16739-1:2018). This digital twin accurately models the mounting plate (160) geometry, including first receiver ears (210) and bays (290), the hinge pin assembly (270), and the locking swing plate (560) with its second receiver ears (610) and major blocking surface (585). The model includes attributes for material properties (e.g., steel alloy, polymer composite), installation tolerances (e.g., required gap between door outside edge and second jamb interior surface), operational states (locked/unlocked positions), and security ratings (e.g., forced entry resistance). Architects and engineers can import this IFC object into open-source BIM software (e.g., FreeCAD with an IFC workbench) to perform virtual installation, clash detection with other building elements (e.g., electrical conduits), and simulate the device's functional clearances within a digital building model before physical construction, ensuring optimal placement and operation.
Integration with Open-Source Physical Access Control System (PACS) Architectures: The mechanical door security device (US11447993B1) is augmented with an electro-mechanical actuation system. This system comprises a low-power, high-torque micro-solenoid connected via a linkage to the locking swing plate (560). This solenoid is controlled by an open-source access control board (e.g., based on an Arduino platform with an Ethernet shield) running a customized firmware implementing an open API for lock control. The access control board interfaces with an open-source RFID reader (e.g., RC522 module) or a fingerprint sensor module. When an authenticated credential is presented (via the open-source PACS frontend), the solenoid is briefly energized to apply an upward force, lifting the locking swing plate (560) from its lowermost locked position (in the locking channel 251) to its uppermost unlocked position (on the major rest 248), thus overcoming the gravity bias and allowing the door to be opened. After a configurable delay, the solenoid de-energizes, allowing gravity to re-engage the lock when the door is closed and the swing plate is returned to the locking angular position. This provides an automated override to the purely mechanical lock while leveraging open-source hardware and software for access control logic.

Derivative Variations

The following derivatives expand upon the core claims of US11447993B1, focusing on Claim 1 and Claim 10 due to their independent nature.

Derivatives from Claim 1

Claim 1 Summary: A door locking device with a mounting plate on the door jamb, a hinge pin assembly, and a gravity-biased locking swing plate. The mounting plate has first receiver ears/bays, and a receiver wall with varying height (major rest, declining slide surface, locking channel). The swing plate pivots, translates, is gravity-biased to a lowermost locked position where its blocking surface abuts the door, and is retained in the channel against pivoting.

Derivative 1.1: Material & Component Substitution - Polymer/Composite Construction for Lightweight Applications

Enabling Description: The mounting plate (160), first receiver ears (210), and the locking swing plate (560) are fabricated from a high-strength, glass-fiber reinforced polycarbonate composite. This material offers superior impact resistance and stiffness-to-weight ratio compared to traditional metals, significantly reducing overall device weight and manufacturing costs through high-volume injection molding. The hinge pin (270) is constructed from a self-lubricating, ultra-high molecular weight polyethylene (UHMW-PE) rod, which provides low-friction pivotal and translational movement within the first receiver aperture (235) and the locking channel (251). This eliminates the need for metallic bearings and prevents galvanic corrosion between dissimilar materials. The plurality of fasteners (165) would be composite-compatible, such as self-tapping, corrosion-resistant alloy steel screws with integrated oversized washers to distribute load evenly across the polymer components. The declining slide surface (340) and locking channel (251) features would have precision-molded surfaces to ensure smooth operation and accurate alignment for gravity biasing, maintaining the specified angular and vertical positional integrity.

Mermaid Diagram:

graph TD
    A[Door Jamb] -- Fasteners (Composite-compatible) --> B(Mounting Plate - Polycarbonate Composite)
    B -- Integral Fixed Relationship --> C(First Receiver Ears - Polycarbonate Composite)
    C -- Hinge Pin (UHMW-PE Rod) --> D(Locking Swing Plate - Polycarbonate Composite)
    D -- Abutting Engagement --> E[Door Interior Surface]
    C -- Varying Height Surface (Precision Molded) --> F{Declining Slide Surface}
    F -- Gravity Biasing --> G{Locking Channel}
    G -- Positively Retained --> D
    G -- Obstruction --> H[Pivoting Movement]

Derivative 1.2: Operational Parameter Expansion - High-Security, High-Cycle Industrial Application

Enabling Description: This derivative is engineered for industrial and institutional environments demanding extreme durability, high-frequency operation, and enhanced forced-entry resistance, such as server rooms or vault entrances. All structural components (mounting plate 160, first receiver ears 210, locking swing plate 560) are machined from hardened aerospace-grade stainless steel (e.g., Carpenter 455 stainless steel) and subsequently coated with a low-friction, high-wear-resistance ceramic-metallic (cermet) coating (e.g., WC/C, Tungsten Carbide/Carbon) for extended lifespan under repetitive stress. The hinge pin assembly (270) incorporates precision-ground, hardened steel pivot bearings (e.g., AISI 52100 steel) with a high dynamic load rating and is sealed to an IP67 rating against dust and moisture ingress. The gravity biasing of the locking swing plate (560) is augmented by a redundant, pre-loaded torsion spring mechanism to ensure rapid and consistent engagement into the lowermost locked position and to maintain higher retention forces against minor jostling. The locking channel (251) features actively managed tolerances through embedded piezoelectric actuators that can momentarily adjust the width of the locking channel's major vertical wall (253) and minor lower wall (254) to compensate for thermal expansion/contraction or wear, ensuring precise alignment and maximum security over a wide operational temperature range (-40°C to +85°C) and for cycle counts exceeding 1,000,000.

Mermaid Diagram:

stateDiagram-v2
    [*] --> Unlocked_Uppermost
    Unlocked_Uppermost --> Engaging: Swing Plate Pivoted
    Engaging --> Locked_Lowermost: Gravity + Torsion Spring Actuation
    Locked_Lowermost --> Unlocking: Manual Intervention (Force > Gravity + Spring)
    Unlocking --> Unlocked_Uppermost: Swing Plate Raised
    Locked_Lowermost --> Resisting_Force: Forced Entry Attempt
    Resisting_Force --> Locked_Lowermost: Hardened Materials + Active Tolerances
    note right of Resisting_Force
        Piezoelectric actuators maintain
        precise engagement geometry
    end note

Derivative 1.3: Cross-Domain Application - Container Security for Intermodal Shipping

Enabling Description: This adaptation targets the security of intermodal shipping container doors, which are exposed to harsh marine and terrestrial environments, dynamic vibrations, and significant brute-force entry risks. The "door jamb" (135) is the internal structural frame of the container, and the "door" (105) is one of the heavy steel swinging doors. The mounting plate (160) is fabricated from high-tensile weathering steel (e.g., ASTM A588) and robustly welded or bolted with high-strength fasteners (e.g., ASTM A325 structural bolts) to the container's interior frame. The locking swing plate (560) is constructed from a reinforced, corrugated steel plate, designed to span a greater distance across the container door's interior surface (120). The hinge pin assembly (270) is replaced with a heavy-duty, corrosion-resistant stainless steel pivot axle system (e.g., 316L stainless steel) with spherical plain bearings, enabling the locking swing plate to pivot and vertically translate even under heavy axial loads. Gravity-biasing is enhanced by a spring-assist mechanism (e.g., heavy-duty coil springs) to ensure positive engagement of the locking swing plate into the locking channel (251) despite severe vibration during transport. The declining slide surface (340) and locking channel (251) are engineered with deeper detents and more pronounced lead-in chamfers to ensure reliable seating and retention. An integrated, hardened steel shroud protects the locking mechanism from external tampering or cutting.

Mermaid Diagram:

flowchart LR
    A[Shipping Container Frame] -- Welding/Heavy Bolts --> B(Mounting Plate - Weathering Steel)
    B -- Pivot Axle System (316L SS) --> C(Locking Swing Plate - Reinforced Corrugated Steel)
    C -- Gravity Biasing + Spring Assist + Deep Detents --> D{Locking Channel (Hardened Steel Shroud)}
    D -- Tamper-Resistant Features --> E[Container Secured]
    C -- Abuts --> F[Container Door Interior]
    style C fill:#add8e6,stroke:#333,stroke-width:2px
    style B fill:#add8e6,stroke:#333,stroke-width:2px

Derivative 1.4: Integration with Emerging Tech - AI-Optimized Predictive Security & Remote Actuation

Enabling Description: This derivative enhances the door security device with AI-driven intelligence and IoT connectivity for adaptive threat response and remote management. The mounting plate (160) and locking swing plate (560) are instrumented with a suite of MEMS sensors: tri-axial accelerometers and gyroscopes on the swing plate (560) to monitor its dynamic state, linear displacement sensors for vertical translation, Hall effect sensors for angular position, and acoustic emission sensors for detecting abnormal sounds (e.g., pry bar attempts). An embedded, ultra-low-power AI inference engine (e.g., a neural network processor on a sub-mW microcontroller) locally processes this real-time sensor data. This AI, pre-trained on a vast dataset of normal door operations, forced entry attempts, and environmental noise, can:
1. Anomaly Detection: Identify suspicious patterns indicative of a forced entry attempt (e.g., specific vibration frequencies, rapid deceleration, repeated impact forces) and immediately trigger an alert.
2. Predictive Maintenance: Monitor wear on the declining slide surface (340) and locking channel (251) by analyzing subtle changes in slide dynamics and engagement sound profiles, scheduling maintenance proactively.
3. Remote Actuation: Integrate a robust, low-backlash stepper motor with a worm gear drive to precisely control the vertical movement of the locking swing plate (560). This allows for remote locking/unlocking via a secure wireless protocol (e.g., LoRaWAN, Thread, or 5G NR-Light) to a cloud-based security platform. A blockchain-based immutable ledger records all lock state changes, sensor anomalies, and remote commands, providing a verifiable audit trail for compliance and forensic analysis.

Mermaid Diagram:

flowchart TD
    A[Locking Swing Plate] -- MEMS Sensors (Accel, Gyro, Displacement, Hall, Acoustic) --> B(Embedded AI Inference Engine)
    B -- Secure Wireless (LoRaWAN/Thread/5G NR-Light) --> C[Cloud Security Platform]
    C -- Blockchain Logging --> D[Immutable Audit Trail]
    B -- Motor Control --> E[Stepper Motor Actuator (Remote Lock/Unlock)]
    F[Declining Slide Surface / Locking Channel] -- Condition Monitoring --> B
    B -- Anomaly Alerts / Predictive Maintenance --> C

Derivative 1.5: The "Inverse" or Failure Mode - Electrically-Activated Emergency Release

Enabling Description: This derivative focuses on a controlled, emergency "fail-open" mechanism, allowing for rapid and safe egress during critical events, even if the primary gravity-biased locking is engaged. The locking swing plate (560) is equipped with an integrated, normally-closed electro-actuator (e.g., a solenoid or shape memory alloy wire) positioned to directly interact with the locking channel's major vertical wall (253) or lower minor wall (254). In its default state, the electro-actuator does not interfere with the gravity-biased locking. However, upon receipt of an emergency signal (e.g., fire alarm, panic button, or remote command from a building management system), a momentary electrical current (sourced from a dedicated, uninterruptible power supply, such as a supercapacitor or long-life battery) is sent to the electro-actuator. This current causes the actuator to momentarily retract or deform, creating a temporary clearance within the locking channel (251) that allows the locking swing plate (560) to pivot freely, overriding the positive retention and releasing the door (105) from its locked position. Once the emergency condition passes or power is removed, the actuator returns to its passive state, allowing the gravity-biased lock to re-engage if the door is closed and the swing plate is appropriately positioned. This system prioritizes emergency egress over security during specified critical events.

Mermaid Diagram:

stateDiagram-v2
    [*] --> Normal_Operating
    Normal_Operating --> Locked_Lowermost: Gravity Engaged
    Normal_Operating --> Unlocked_Uppermost: Manual Lift
    Locked_Lowermost --> Emergency_Release_Activated: Emergency Signal Received
    Emergency_Release_Activated --> Electro_Actuator_Engaged: Power to Actuator
    Electro_Actuator_Engaged --> Channel_Clearance: Momentary Deform/Retract Wall
    Channel_Clearance --> Door_Freely_Opens: Overrides Positive Retention
    Door_Freely_Opens --> Unlocked_Uppermost: (Upon door opening)
    Electro_Actuator_Engaged --> Normal_Operating: Power Removed (Actuator Resets)
    note right of Emergency_Release_Activated
        Low-power electrical pulse
        from local UPS
    end note

Derivatives from Claim 10

Claim 10 Summary: Similar to Claim 1, but with more detailed structural specifications for the first receiver wall and the components of the locking channel, emphasizing features like inner/outer radii, varying height transitions, and the "neck portion" engagement.

Derivative 2.1: Material & Component Substitution - Self-Healing Polymer & Shape Memory Alloy Actuation

Enabling Description: The critical elements of the first receiver wall (222), including the first major rest (248), declining slide surface (340), and the locking channel (251) components (major wall, lower wall, upper wall), are fabricated from a multi-phase, self-healing polymer composite (e.g., a thermosetting polymer matrix embedding microcapsules of a liquid healing agent and a catalyst). This material enables autonomous repair of minor surface abrasions, micro-cracks, or small impact deformations that could compromise the precision of the sliding surfaces or the rigidity of the locking channel, extending the device's operational life without manual intervention. Furthermore, the locking channel major wall (253) and opposed locking channel minor lower wall (254) incorporate embedded shape memory alloy (SMA) micro-actuators (e.g., arrays of Nitinol wires). Upon detection of significant deformation (e.g., from a severe forced entry attempt) via integrated strain gauges, a precise electrical pulse is applied to the SMA elements. This activation causes the SMA to revert to its pre-programmed "memory" shape, dynamically restoring the original geometry and dimensional integrity of the locking channel walls, thereby recovering the precise alignment and positive retention capacity of the locking swing plate (560) and its neck portion (615).

Mermaid Diagram:

flowchart LR
    A[First Receiver Wall (Self-Healing Polymer Composite)] -- Minor Damage --> B(Healing Agent Release/Polymerization)
    B -- Autonomous Repair --> A
    C[Locking Channel Walls] -- Embedded SMA Micro-Actuators --> D{Integrated Strain Gauges}
    D -- Deformation Detected --> E(Control Circuit)
    E -- Electrical Pulse --> F[SMA Activation/Shape Recovery]
    F -- Restores Geometry --> C
    C -- Receives Neck Portion --> G[Locking Swing Plate]

Derivative 2.2: Operational Parameter Expansion - Vacuum/Low-Pressure Environment Control with Magnetic Latching

Enabling Description: This derivative adapts the door security device for rigorous operation in controlled vacuum or low-pressure cleanroom environments (e.g., specialized laboratories, space simulation facilities, or semiconductor manufacturing cleanrooms). All components, including the mounting plate (160), first receiver ears (210), and locking swing plate (560), are manufactured from ultra-high vacuum (UHV) compatible materials, such as specific grades of stainless steel (e.g., 304L or 316L electropolished), high-purity ceramics for bearings, and specialized low-outgassing polymers (e.g., PEEK, PTFE) for seals and damping elements. Dry film lubricants (e.g., MoS2) are applied to all contact surfaces to ensure smooth operation in the absence of atmospheric lubricants. The gravity-biasing mechanism is augmented or entirely replaced by a precisely calibrated magnetic latching system. Strong, radiation-hardened rare-earth permanent magnets (e.g., SmCo) are embedded in the locking swing plate (560) and strategically placed in the locking channel (251) and major rest (248) of the first receiver wall (222). These magnets provide the necessary biasing force to move the swing plate into the lowermost locked position and retain it, overcoming the diminished gravitational effect in low-pressure environments. The declining slide surface (340) is highly polished (Ra < 0.02 µm) and features a carefully designed magnetic force profile to guide the locking swing plate smoothly and precisely into its positive retention slot, minimizing particulate generation, which is critical in cleanroom applications. Position sensing utilizes non-contact eddy current sensors or optical interrupters, all UHV-rated.

Mermaid Diagram:

graph TD
    A[Low-Pressure/Vacuum Environment] --> B(UHV-Compatible Components)
    B -- Mounting Plate (Electropolished SS) --> C(First Receiver Wall)
    C -- Magnetic Latching (SmCo Magnets) --> D(Locking Swing Plate)
    D -- Abutting Engagement --> E[Cleanroom Door]
    C -- Highly Polished Surfaces --> F{Declining Slide Surface w/ Magnetic Profile}
    F -- Precise Alignment (Non-contact Sensors) --> G{Locking Channel (UHV-rated)}
    G -- Magnetic Retention --> D

Derivative 2.3: Cross-Domain Application - Robotic Arm Safety Interlock

Enabling Description: This device is adapted as a safety interlock for high-payload industrial robotic arms, ensuring the arm is positively locked in a "safe" or "maintenance" angular position when not operational, preventing inadvertent movement. The "door jamb" is the robot's base or frame, and the "door" is the robotic arm segment or end effector. The mounting plate (160) is securely bolted to a fixed structural member of the robot chassis. The locking swing plate (560) is a robust, lightweight alloy component attached to a pivot point on the robotic arm. The "hinge pin vertical axis" (275) is re-imagined as a multi-axis pivot mechanism allowing the locking swing plate to pivot and translate relative to the robotic arm's joint. The first receiver wall (222) and its associated major rest (248), declining slide surface (340), and locking channel (251) are scaled and hardened to withstand the significant forces and torques exerted by a robotic arm. The declining slide surface (340) precisely guides a reinforced neck portion (615) of the locking swing plate (560) into the locking channel (251) when the arm is manually maneuvered into the safe position. The gravity biasing for the swing plate's movement to the lowermost locked position is augmented by a robust spring-loaded mechanism to ensure positive engagement even if the robotic arm is in an unusual orientation (i.e., not perfectly vertical, where gravity's effect might be reduced). The locking channel's major wall (253) and minor lower wall (254) are precision-machined to interlock with the neck portion (615), physically preventing any pivotal movement of the arm out of the safe position.

Mermaid Diagram:

classDiagram
    class RoboticArmSafetyInterlock {
        +MountingPlate robot_chassis_mounted
        +LockingSwingPlate lightweight_alloy
        +MultiAxisPivot mechanism
        +ReceiverWall hardened_steel
        +DecliningSlideSurface precision_machined
        +LockingChannel high_force_retention
        +SpringAssistMechanism
    }
    class MountingPlate {
        +fasteners: industrial_grade_bolts[]
    }
    class LockingSwingPlate {
        +neckPortion: reinforced_alloy
        +blockingFeature: arm_joint_interlock
    }
    RoboticArmSafetyInterlock *-- MountingPlate
    RoboticArmSafetyInterlock *-- LockingSwingPlate

Derivative 2.4: Integration with Emerging Tech - Digital Twin for Self-Diagnosing & Self-Calibrating Locks

Enabling Description: This derivative implements a comprehensive digital twin strategy for the door security device (US11447993B1) to achieve self-diagnosis, predictive maintenance, and autonomous calibration. Each physical device is equipped with a high-density array of micro-sensors: linear variable differential transformers (LVDTs) for sub-micron precision vertical translation measurement of the locking swing plate (560), high-resolution rotary encoders for pivotal angle, distributed fiber optic strain sensors along the entire first receiver wall (222), and embedded temperature sensors. This rich, real-time sensor data is continuously transmitted via a secure low-latency 5G or Wi-Fi 6E network to a cloud-based digital twin platform. The digital twin, running advanced simulation models (e.g., FEM for stress analysis, kinematic models for movement), perpetually analyzes the physical device's operational behavior against its ideal state. An integrated AI/ML model within the digital twin identifies deviations, predicts wear on the declining slide surface (340) and locking channel (251) at a micro-level, and anticipates potential failures. The AI then autonomously generates commands for micro-actuators (e.g., piezoelectric positioners or fine-pitch lead screws) embedded within the mounting plate (160) to dynamically adjust the geometry of the locking channel (251) – specifically, the position of the major wall (253) or lower wall (254) – or the incline of the declining slide surface (340). This allows the lock to adapt and maintain optimal functionality and security performance, compensating for material fatigue, environmental changes, or accumulated wear without human intervention. All diagnostic data, adjustments, and predictions are logged on a private blockchain for verifiable auditability.

Mermaid Diagram:

sequenceDiagram
    participant P as Physical Device
    participant S as Sensor Array (LVDT, Encoders, Fiber Optic Strain, Temp)
    participant M as Micro-Actuators
    participant C as 5G/Wi-Fi 6E Network / Cloud Platform
    participant D as Digital Twin (AI/ML Model & Simulations)

    P->>S: Real-time Operational Data
    S->>C: Stream High-Res Data
    C->>D: Update Digital Twin State
    D->>D: Analyze, Predict Wear, Identify Deviations
    D->>C: Generate Calibration Commands / Alerts
    C->>M: Transmit Micro-Actuator Adjustments
    M->>P: Self-Calibrate Locking Geometry
    D->>C: Log Diagnostics to Private Blockchain

Derivative 2.5: The "Inverse" or Failure Mode - Intelligent, Controlled Degradation for Temporary Security

Enabling Description: This derivative is designed for temporary security applications where post-use environmental impact is a primary concern, such as construction site access control, temporary event security, or rapid deployment scenarios. The mounting plate (160), first receiver ears (210), and locking swing plate (560) are manufactured from advanced bio-degradable polymer composites (e.g., polyhydroxyalkanoates (PHA) or engineered polylactic acid (PLA) with controlled degradation kinetics), reinforced with natural fibers (e.g., basalt or flax) for initial strength. The hinge pin assembly components are similarly bio-polymer based. Integrated into the polymer matrix are sacrificial, environmentally responsive elements (e.g., encapsulated enzymes or pH-sensitive activators) that initiate controlled degradation after a pre-programmed time or upon exposure to specific environmental triggers (e.g., sustained humidity >90% or specific pH levels). The design of the declining slide surface (340) and the locking channel (251) explicitly accounts for this degradation. Initially, the device functions perfectly, providing full security. However, as the degradation process begins, the polymer matrix surrounding critical features (like the locking channel major wall 253 and minor lower wall 254) gradually softens or erodes. This leads to a predictable and safe failure mode where the precise engagement of the neck portion (615) of the locking swing plate (560) within the channel is compromised. The device eventually transitions from a "fully secured" state to a "limited security" state (where only a friction fit remains) and finally to a "non-functional" state (where the swing plate cannot retain its lowermost position), preventing false security impressions for long-term use, while ensuring the components safely break down into benign organic compounds.

Mermaid Diagram:

stateDiagram-v2
    [*] --> Initial_Deployment_Active
    Initial_Deployment_Active --> Fully_Secured: Operates per Patent (Bio-Polymer)
    Fully_Secured --> Degradation_Initiated: Time Trigger / Environmental Trigger
    Degradation_Initiated --> Gradual_Erosion: Polymer Matrix Softens/Erodes
    Gradual_Erosion --> Limited_Security: Precision of Locking Channel Compromised
    Limited_Security --> Non_Functional: Cannot Retain Lowermost Position
    Non_Functional --> Fully_Degraded: Biodegradation Complete
    note right of Degradation_Initiated
        Encapsulated enzymes or
        pH-sensitive activators
    end note