US 11447993

Here's a concise summary of US Patent 11447993:

• Patent Number: US11447993B1
• Title: Door security device
• Assignee: Notrox LLC
• Inventor: John Reger
• Filing Date: November 22, 2021
• Issue Date: September 20, 2022
• Abstract: A door security device for an in-swing door includes a mounting plate secured to the door jamb adjacent the door outside edge, a hinge pin assembly supported by the mounting plate proximate the door outside edge, a locking swing plate secured to the hinge pin assembly for pivotal movement between unlocked and locked angular positions in relation to the hinge pin vertical axis, the locking swing plate biased by force of gravity to a lowermost position, and the mounting plate having a first receiver wall defining the lowermost position of the locking swing plate in the locked position perpendicular to a first rear surface of the mounting plate and defining the uppermost position of the locking swing plate in the unlocked position away from the locked angular position.

Plain-Language Overview of Independent Claims:

• Claim 1: This claim describes a door locking device designed to prevent forced entry through an in-swing door. The device includes a mounting plate that fastens to the door jamb next to the door's outside edge. This mounting plate features a series of "first receiver ears" and "first receiver bays" arranged along a central hinge pin axis. A "locking swing plate" has corresponding "second receiver ears" that fit into these bays. The first receiver ears are uniquely shaped with a "first major rest" at their highest point (for an unlocked position), a "declining slide surface," and a "first locking channel" at their lowest point (for a locked position). The locking swing plate can both pivot and move up and down. When the swing plate is rotated into a "locking angular position" and allowed to drop to its "lowermost vertical position," a "major blocking surface" on the plate presses against the inside surface of the door, securing it. The design ensures that gravity pulls the swing plate into and holds it in this locked position, preventing it from pivoting out of place unless a user manually lifts it.
• Claim 10: This claim further details the door locking device, specifically elaborating on the "first receiver wall" component of the mounting plate. It highlights that this wall has a varying height, with a "first major rest" defining its maximum height and a "locking channel bottom wall" defining its minimum height. A "declining slide surface" connects these two heights, sloping downward. The "locking channel" is described as an open slot that passes through the receiver wall. This channel, along with other walls and surfaces, guides a "neck portion" of the locking swing plate's receiver into the channel. Similar to Claim 1, this claim emphasizes that gravity biases the locking swing plate into its lowermost, locked position within this channel, where its blocking surface abuts the door's interior surface to prevent forced entry. The locking swing plate remains fixed in this position until manually lifted by a user.

Legal Status and CAFC Dockets:
US Patent 11447993B1 is currently Active, with an anticipated expiration date of November 22, 2041. No specific dockets related to patent 11447993 were found in the provided CAFC 2026 docket search results.

As of April 26, 2026, there is no known litigation involving US Patent 11447993. Searches on Unified Patents and other general litigation databases for the specific patent number did not yield any results for District Court, Supreme Court, United States Court of Federal Claims, CAFC, or ITC cases. While Unified Patents is active in contesting patents through USPTO's post-grant proceedings, and provides litigation alerts, there are no records indicating their involvement with US11447993.

Proceedings overview

There is no PTAB activity on file for US Patent 11447993.

Strategic summary

As of June 15, 2026, all claims of US Patent 11447993 remain untested in AIA trial proceedings. This means there are no canceled or sustained claims through PTAB review, and the entire patent is vulnerable to challenge on any valid prior art grounds. The absence of PTAB activity could suggest several things: the patent has not yet been widely asserted, it is relatively new, or potential challengers have not identified strong prior art.

Given the lack of PTAB proceedings, there is no estoppel landscape established under § 315(e)(2). Therefore, all prior-art grounds (e.g., anticipation under § 102 or obviousness under § 103) are still available for a defendant facing assertion of this patent. There is no evidence of repeated challenges by the same petitioner or aggressive appeals by the patent owner.

Recommended next steps

Since no PTAB activity exists for US Patent 11447993, a potential defendant has a full range of options for challenging the patent's validity through an AIA trial, such as an Inter Partes Review (IPR), if suitable prior art can be identified.

Inventors

• John Reger (Notrox LLC)

Original assignee

Notrox LLC is the original assignee named on the issued patent. The provided patent text does not contain information about whether Notrox LLC ships a product embodying the claims, its primary line of business, or its current status (operating, acquired, dissolved, in bankruptcy).

Assignment timeline

No assignment records were found for US Patent 11447993 on the USPTO Assignment Center. This indicates that the patent ownership likely remains with the original assignee, Notrox LLC.

Timeline diagram

timeline
    title Ownership of US 11447993
    2021 : Filed by Notrox LLC
    2022 : Issued to Notrox LLC

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No transfers are recorded.
2. Known asserter in the chain — not present. No transfers are recorded.
3. Repeat correspondent across the chain — not present. No transfers are recorded.
4. Cascading transfers — not present. No transfers are recorded.
5. Pre-litigation transfer — not present. No transfers are recorded.
6. Bankruptcy fire-sale — not present. No transfers are recorded.
7. Privateering — not present. No transfers are recorded.
8. Defensive aggregator (anti-NPE) — not present. No transfers are recorded.

Verdict

Insufficient data. The absence of any recorded assignments on the USPTO Assignment Center means there is no information available to determine if the patent has been transferred to an NPE or any other entity.

To identify the most relevant prior art for US Patent 11447993, I will analyze the patent citations listed within the patent itself. The USPTO's Patent Public Search tool is an authoritative source for this information.

Here's an analysis of the cited prior art:

Prior Art Cited in US Patent 11447993

1. US2794665A - Night latch

• Full Citation: US2794665A, Sasse Reuben, "Night latch", published June 4, 1957, filed June 20, 1955.
• Brief Description: This patent describes a night latch mechanism.
• Potential Anticipation (35 U.S.C. § 102): While broadly related to door security, it's unlikely to anticipate the specific mechanical and gravity-biased locking features of US11447993, particularly the mounting plate with receiver ears/bays, declining slide surface, and locking channel that interacts with a vertically translating and pivoting locking swing plate. It may be cited for the general concept of a door locking mechanism.

2. US3431591A - Selectively releasable engageable separable-leaf hinge

• Full Citation: US3431591A, Ludwig & Co Inc A, "Selectively releasable engageable separable-leaf hinge", published March 11, 1969, filed June 5, 1967.
• Brief Description: This patent describes a hinge that can be selectively released or separated.
• Potential Anticipation (35 U.S.C. § 102): This reference might be relevant for its hinge mechanisms. However, US11447993 focuses on a security device that attaches to a door jamb and works with a hinge pin assembly, rather than a hinge itself. It's unlikely to anticipate the specific interaction of the locking swing plate, declining slide surface, and locking channel. It might be relevant to the broad concept of components interacting along a hinge pin axis.

3. US3810667A - Latch

• Full Citation: US3810667A, T Dugan, "Latch", published May 14, 1974, filed August 9, 1971.
• Brief Description: This patent describes a latch mechanism.
• Potential Anticipation (35 U.S.C. § 102): Similar to US2794665A, this patent is broadly related to door security. However, it's unlikely to anticipate the detailed structural and functional features of the gravity-biased, vertically translating, and pivoting locking swing plate and its interaction with the mounting plate's declining slide surface and locking channel as described in claims 1 and 10 of US11447993.

4. US6353967B1 - Ninety-degree door hinge

• Full Citation: US6353967B1, Francisco A. Escobar, "Ninety-degree door hinge", published March 12, 2002, filed September 2, 1998.
• Brief Description: This patent describes a door hinge designed to allow a door to open to a ninety-degree angle.
• Potential Anticipation (35 U.S.C. § 102): This patent might be relevant for hinges that control door opening angles. However, it's distinct from the security device of US11447993, which provides a secondary locking mechanism rather than a primary hinge function. The specific gravity-biased locking mechanism of US11447993 is not present.

5. US20050046201A1 - Portable security locks

• Full Citation: US20050046201A1, Thomas Patire, "Portable security locks", published March 3, 2005, filed August 28, 2003.
• Brief Description: This patent describes portable security locks.
• Potential Anticipation (35 U.S.C. § 102): This reference deals with portable security, which is a different category than the permanently installed device of US11447993. While both aim for door security, the specific structural components and gravity-activated locking mechanism of US11447993 are not found in the concept of a portable lock.

6. US20090217485A1 - Hinges

• Full Citation: US20090217485A1, Kenneth Springer, "Hinges", published September 3, 2009, filed July 17, 2004.
• Brief Description: This patent describes various hinge designs.
• Potential Anticipation (35 U.S.C. § 102): Similar to US3431591A and US6353967B1, this patent focuses on hinge constructions. It is unlikely to anticipate the unique combination of a mounting plate, locking swing plate, and gravity-biased locking interaction described in US11447993.

7. US20100251520A1 - Loose-Pin Hinge and Hinge Pin with Integrated Stop

• Full Citation: US20100251520A1, Salvatore Corso, "Loose-Pin Hinge and Hinge Pin with Integrated Stop", published October 7, 2010, filed April 1, 2009.
• Brief Description: This patent describes a loose-pin hinge with an integrated stop feature.
• Potential Anticipation (35 U.S.C. § 102): This patent is more relevant as it describes a hinge pin with an integrated stop. However, the mechanism of US11447993 is a separate security device, not the hinge itself, and its gravity-biased locking action, particularly the declining slide surface and locking channel interacting with a swing plate, is distinct from a simple hinge pin stop. It might potentially anticipate aspects of how a hinge pin interacts with a stopping mechanism, but not the overall claims of US11447993.

8. US20110156409A1 - Door guard

• Full Citation: US20110156409A1, Alvarenga Francisco J, "Door guard", published June 30, 2011, filed December 30, 2009.
• Brief Description: This patent describes a door guard device.
• Potential Anticipation (35 U.S.C. § 102): This is a general door security device. Without further details, it's difficult to assess direct anticipation, but the specific mechanical features of US11447993, such as the varied height receiver wall, declining slide surface, and gravity-driven locking swing plate, are likely to be distinguishable from a generic "door guard."

9. US8534721B1 - Closure restraint system

• Full Citation: US8534721B1, John H. Boggs, "Closure restraint system", published September 17, 2013, filed March 15, 2011.
• Brief Description: This patent describes a system for restraining a closure, such as a door.
• Potential Anticipation (35 U.S.C. § 102): This patent could be a significant reference given its title. A "closure restraint system" might encompass mechanisms for preventing a door from opening. A detailed comparison would be needed to determine if the specific elements of Claims 1 and 10, particularly the gravity-biased, vertically translating, and pivoting locking swing plate interacting with the mounting plate's declining slide surface and locking channel, are present in US8534721B1.

10. US20160298361A1 - Strike Plate Lock

• Full Citation: US20160298361A1, Robert Francis Dieguez, "Strike Plate Lock", published October 13, 2016, filed April 16, 2014.
• Brief Description: This patent describes a strike plate lock.
• Potential Anticipation (35 U.S.C. § 102): A strike plate lock is a common door security component. While it serves a similar purpose, the mechanism described in US11447993 is a distinct, supplementary security device mounted to the door jamb with a pivoting and translating locking swing plate, which is different from a typical strike plate enhancement. Therefore, direct anticipation of the specific claims of US11447993 is unlikely.

Summary of Potential Anticipation:

Based on the brief descriptions, none of the cited prior art appears to fully anticipate all elements of Claim 1 or Claim 10 of US11447993. The unique combination of a mounting plate with varying height receiver walls, a declining slide surface, and a locking channel, which cooperate with a gravity-biased, vertically translating, and pivoting locking swing plate to secure an in-swing door, seems to be a distinguishing feature.

However, the following patents warrant closer examination for potential obviousness challenges (under 35 U.S.C. § 103) or for specific elements within broader claims:

• US20100251520A1 (Loose-Pin Hinge and Hinge Pin with Integrated Stop): Could be relevant to the general concept of a stop mechanism interacting with a hinge pin.
• US8534721B1 (Closure restraint system): The broad nature of a "closure restraint system" means a detailed review is essential to determine if any of its embodiments contain elements similar enough to anticipate or render obvious the gravity-biased locking swing plate and its interaction with the mounting plate's varied receiver wall and channels.

Without access to the full details and drawings of these cited patents and a side-by-side comparison of each claim element, definitive statements about anticipation are difficult. The analysis above provides an initial assessment based on the titles and brief descriptions.

Obviousness Analysis for US Patent 11447993 under 35 U.S.C. § 103

This analysis aims to identify combinations of prior art references that would render the claims of US Patent 11447993 obvious to a person having ordinary skill in the art (POSA). The core distinguishing features of US11447993, as identified in the anticipation analysis, are the specific interaction of a mounting plate with varying height receiver walls, a declining slide surface, and a locking channel, which cooperates with a gravity-biased, vertically translating, and pivoting locking swing plate to secure an in-swing door.

General Considerations for Obviousness:

For a patent claim to be obvious, a POSA must have had a reason to combine known prior art elements in the way claimed, with a reasonable expectation of success. This motivation can come from various sources, such as:

• Explicit suggestions in the prior art: One reference might suggest combining with another.
• Implicit suggestions: The nature of the problem being solved or the functions of the devices might suggest a combination.
• Common sense or general knowledge: A POSA might combine known elements using their general knowledge in the field.
• Known design choices: When a design need arises, and there are a finite number of identified solutions, a POSA might combine them.

Combinations of Prior Art for Obviousness:

Given the unique gravity-biased, vertically translating, and pivoting locking swing plate interacting with a specially designed mounting plate, the most promising avenues for obviousness challenges would likely involve combining a general door restraint or locking system with a hinge or hinge-related stop mechanism that incorporates vertical movement and gravity biasing.

Here are potential combinations and the motivation for a POSA to combine them, focusing on independent claims 1 and 10:

Combination 1: US8534721B1 (Closure restraint system) in view of US20100251520A1 (Loose-Pin Hinge and Hinge Pin with Integrated Stop)

• US8534721B1 (Closure restraint system): This patent broadly describes a system for restraining a closure, such as a door. While the specific mechanical details of US11447993 are likely not directly anticipated, US8534721B1 would establish the general concept of a device designed to prevent a door from opening. Its disclosure would likely include the need for the restraint to engage the door and the door frame.

• US20100251520A1 (Loose-Pin Hinge and Hinge Pin with Integrated Stop): This patent describes a loose-pin hinge with an integrated stop feature. Critically, this reference introduces the idea of a stop mechanism interacting with a hinge pin and possibly involving a loose pin that can move or be removed. While not identical to the gravity-biased swing plate, it demonstrates a known approach to controlling door movement through a hinge-related component.

• Motivation for Combination: A person of ordinary skill in the art, seeking to improve the security of an in-swing door using a closure restraint system (as taught by US8534721B1), would be motivated to look for robust and easily operable locking mechanisms. The concept of an "integrated stop" within a hinge pin assembly (from US20100251520A1) would suggest a mechanism that could leverage the existing hinge structure or a component operating similarly.

  • Reasoning for elements of Claim 1 & 10:
    • Mounting Plate & Hinge Pin Assembly: US8534721B1 would provide the motivation for a door restraint, which inherently requires attachment to the door frame. Incorporating elements related to a hinge pin, as taught by US20100251520A1, would lead to placing components proximate a hinge pin vertical axis.
    • Receiver Ears/Bays and Locking Swing Plate: While US20100251520A1 shows a stop integrated within the hinge, a POSA, seeking to create a more robust external locking mechanism as part of a general restraint system, would consider an arrangement where a separate locking element (like US11447993's locking swing plate) could interact with a fixed mounting plate. The idea of interdigitating elements (ears and bays) along a hinge pin for stability and movement control is a common mechanical design principle.
    • Vertical Translation and Gravity Biasing: The "loose-pin" aspect of US20100251520A1 implicitly suggests vertical movement. Combining this with the desire for a simple, reliable locking action in a security device (from US8534721B1), a POSA would find it obvious to use gravity to bias a movable locking element into a secured position. This is a common and desirable feature for mechanical locks.
    • Declining Slide Surface and Locking Channel: To achieve gravity-biased locking with vertical movement, a declining slide surface guiding a movable element into a locking channel is a well-known mechanical solution for engaging and disengaging. A POSA, starting with the idea of a stop (US20100251520A1) and seeking to make it gravity-actuated within an external restraint system (US8534721B1), would find this design choice obvious. The varying height of the receiver wall, creating the major rest and the lower locking channel, is a logical implementation of this gravity-biased engagement.
    • Blocking Surface: Both references would implicitly or explicitly involve a blocking surface to prevent door movement. Combining the door restraint concept of US8534721B1 with a hinge-related stop, a POSA would recognize the need for the locking element to abut the door's interior surface.

Combination 2: US20110156409A1 (Door guard) in view of US3431591A (Selectively releasable engageable separable-leaf hinge) and general mechanical principles.

• US20110156409A1 (Door guard): This patent provides the broad concept of a "door guard" device for security. It establishes the problem being solved by US11447993: securing an in-swing door against forced entry.

• US3431591A (Selectively releasable engageable separable-leaf hinge): This patent describes a hinge that can be selectively released or separated. This reference introduces the idea of controlling the connection and disconnection of hinge components. While not specifically a security device, it highlights mechanisms for manipulating parts around a hinge axis.

• Motivation for Combination: A POSA designing an improved "door guard" (US20110156409A1) might seek to integrate it more effectively with the door's existing structure, such as the hinge. The concept of "selectively releasable" hinge elements (US3431591A) would motivate a POSA to consider mechanisms that allow for controlled engagement and disengagement of a security feature.

  • Reasoning for elements of Claim 1 & 10:
    • Mounting Plate & Locking Swing Plate: A door guard needs to be mounted. If integrating with the hinge area, a mounting plate on the jamb would be obvious. The "selectively releasable" idea would suggest a separate, movable component (like the locking swing plate) that engages with the mounting plate.
    • Pivoting Movement & Vertical Translation: Hinge elements inherently pivot. The "selectively releasable" aspect of US3431591A could involve some degree of translation (e.g., lifting a pin). Combining these, a POSA would find it obvious to design a locking mechanism that pivots to engage/disengage and translates vertically for positive locking.
    • Gravity Biasing: For a security device, a fail-safe or automatically engaging mechanism is desirable. Using gravity to bias the movable element (locking swing plate) into a locked position (lowermost) is a well-known and obvious mechanical principle for reliability and ease of use.
    • Varying Height Receiver Wall, Declining Slide Surface, Locking Channel: To achieve vertical translation and gravity-biased locking, a cam-like action provided by a declining slide surface guiding a component into a recess (locking channel) is a standard mechanical design. The "varying height receiver wall" simply describes the geometry needed to implement this camming and locking action.

Other Potentially Relevant Prior Art for Specific Elements:

• US2794665A (Night latch) and US3810667A (Latch): While these are general latch mechanisms, they reinforce the common knowledge of door locking and the various ways latches can engage to secure a door. A POSA would understand the functional requirements of a secure latch from these.
• US6353967B1 (Ninety-degree door hinge) and US20090217485A1 (Hinges): These references illustrate various hinge constructions and how hinges control door movement. While not directly teaching the security device, they provide context on hinge design and the interaction of hinge leaves and pins, which could inform the design of the receiver ears and bays.
• US20050046201A1 (Portable security locks) and US20160298361A1 (Strike Plate Lock): These represent different types of door security, showing that the field has a variety of solutions. A POSA might be motivated to combine features from different security device types to create a more robust or user-friendly solution.

Conclusion on Obviousness:

While US11447993 presents a specific combination of features, a strong argument for obviousness could be made by combining the general concept of a door restraint/guard (US8534721B1 or US20110156409A1) with known hinge-related stop mechanisms or selectively releasable hinge elements (US20100251520A1 or US3431591A). The motivation would stem from the desire to create a robust and reliable security device for in-swing doors that leverages simple mechanical principles like gravity for engagement and disengagement. The specific design elements like the declining slide surface and locking channel for gravity-biased vertical translation are common mechanical solutions that a POSA would readily apply once the overall functional objective (gravity-actuated, vertically translating, pivoting lock) is conceived.

Without full access to the cited prior art patents' detailed descriptions and figures, this analysis remains an initial assessment. A thorough obviousness rejection would require a more in-depth, claim-by-claim analysis against specific disclosures within these and potentially other relevant prior art references.

As a technical patent analyst, I've gathered the following information regarding US Patent 11447993B1:

Patent Term Adjustments (PTA)

Patent Term Adjustment (PTA) is granted to compensate for delays caused by the USPTO during the prosecution of a patent application. This adjustment adds to the standard 20-year patent term from the filing date. The USPTO automatically determines the PTA and issues a notice with the patent.

To determine the specific PTA for US11447993B1, a direct query to the USPTO Patent Center or a review of the patent's electronic file wrapper would be necessary. The provided information does not explicitly state the PTA for this patent.

Patent Term Extensions (PTE)

Patent Term Extensions (PTE) are available for patents claiming certain human drug products, medical devices, animal drugs, or food/color additives to restore time lost due to premarket government approval.

Given that US11447993B1 is titled "Door security device" and pertains to mechanical security, it is highly unlikely to be eligible for a Patent Term Extension under 35 U.S.C. § 156, as it does not fall into the categories of products requiring premarket regulatory approval. There is no indication in the provided patent information that a PTE has been applied for or granted for this patent.

Continuation and Divisional Applications

• Continuation Applications: A patent granted on a continuation application filed on or after June 8, 1995, will have a term ending 20 years from the filing date of the earliest application for which a benefit is claimed.
• Divisional Applications: Similar to continuation applications, a patent granted on a divisional application filed on or after June 8, 1995, will also have a term ending 20 years from the filing date of the earliest application for which a benefit is claimed.

The provided patent information for US11447993B1 lists the following priority applications and related child applications:

• US17/532,418: This is the application number for US11447993B1 itself, filed on 2021-11-22.
• US17/881,025 (US11619083B1): This is listed as a "Continuation" application with a priority date of 2021-11-22 and a filing date of 2022-08-04. This indicates that US11619083B1 is a continuation of US17/532,418 (the application for US11447993B1).
• US18/114,385 (US12173535B2): This is also listed as having a priority date of 2021-11-22 and a filing date of 2023-02-27. While not explicitly labeled "continuation" or "divisional" in the same way as US17/881,025, its priority to the original filing date suggests it is a related family member (likely a continuation or divisional).

Related Family Members

The patent explicitly lists the following related family members:

• US11447993B1 (this patent)
• US11619083B1 (a continuation of the application for US11447993B1)
• US12173535B2 (a further related application, also claiming priority to the original filing date of US11447993B1's application)

Projected Expiration Date

The standard term for U.S. utility patents issued from applications filed on or after June 8, 1995, is 20 years from the earliest filing date of the application, subject to any patent term adjustments or extensions.

For US11447993B1:

• Filing Date: 2021-11-22
• Standard 20-year term expiration: 2041-11-22

The patent information provided already states an "Anticipated expiration" date of 2041-11-22, which aligns with the standard 20-year term from the filing date. This date would be adjusted by any Patent Term Adjustment (PTA) that might have been granted due to USPTO delays during prosecution. Without specific PTA data, the anticipated expiration remains the 20-year mark from the filing date.

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:

1. 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.

2. 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.

3. 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.

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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