Anti-theft security system for backflow preventers

Abstract

An embodiment of the invention provides an anti-theft system for backflow preventers comprising a steel bar with specialized catches and protective flanges that integrate with existing protective cages. The preferred embodiment utilizes a modified rebar or steel bar of standard length with T-catches, rectangular flanges with precisely sized holes, and square tubing designed to shield a lock from tampering. An embodiment of the invention can be installed directly in the field through basic modifications to existing cages, creating multiple layers of security that prevent unauthorized access and removal. The preferred embodiment provides a cost-effective solution compared to backflow preventer replacement costs.

Description

PATENT COOPERATION TREATY (PCT) PATENT APPLICATION ANTI-THEFT SECURITY SYSTEM FOR BACKFLOW PREVENTERS Inventor: Kevin WhithamCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No.63 / 720,607, filed November 14, 2024, entitled "Anti-Theft Security System For Backflow Preventers," the entire disclosure of which is hereby incorporated by reference.FIELD OF THE INVENTION

[0002] The present invention relates generally to anti-theft security systems and devices. More particularly, the invention relates to security systems for protecting backflow preventers and other utility equipment from theft, and specifically to retrofit security systems that can be installed on existing protective cages to enhance their theft resistance through improved lock protection mechanisms.BACKGROUND OF THE INVENTION

[0003] Backflow preventers serve a critical public health function by preventing contamination of drinking water systems, particularly during events like rainstorms. These devices are government-mandated and are commonly installed in various settings including residential areas (HO As and apartment complexes), commercial buildings, and public spaces like parks.

[0004] A significant problem has emerged regarding the theft of these essential devices.Backflow preventers contain valuable brass and copper components, weighing approximately 30 pounds, making them attractive targets for theft. Thieves steal these devices to sell them for scrap metal value, similar to catalytic converter theft.

[0005] The financial impact of these thefts is substantial. A new backflow preventer costs between $l,400-$l,600 to replace. For example, in Denver alone during 2023, the city suffered losses of approximately $300,000 due to stolen backflow preventers from their 904 installations. The recurring nature of these thefts is particularly problematic, as thieves often target the same locations repeatedly after replacement devices are installed.

[0006] This situation has created an urgent need for an effective anti-theft solution, particularly in public spaces like parks where theft is especially prevalent. The financial burden on municipalities, businesses, and property owners, combined with the potential public health risksfrom compromised backflow prevention systems, demonstrates the critical nature of this problem.SUMMARY OF THE INVENTION

[0007] An embodiment of the invention provides an anti-theft system for backflow preventers that integrates with existing protective cages. The preferred embodiment comprises a modified rebar or 1 / 4" thick steel bar of standard length (approximately 13.75 inches in the preferred embodiment, but in varying embodiments a length of 12 inches-24 inches), strategically placed steel flanges with rectangular aspects, and a specialized lock protection system.

[0008] The preferred embodiment incorporates T-catches on one side of the bar and corresponding catches on the opposite side, working in conjunction with precisely engineered holes in the steel flanges. While a T-shaped catch configuration is shown in the illustrated embodiment, the catch mechanism may alternatively comprise a circular-shaped catch or other geometry that prevents withdrawal of the bar once the lock is engaged. An embodiment of the invention features square tubing specifically designed to shield the U-part of the lock from tampering attempts.

[0009] Installation of an embodiment of the invention is accomplished through basic modifications to existing protective cages, requiring only the cutting of appropriately sized holes to accommodate the security assembly. The preferred embodiment's components work together to prevent unauthorized access to the backflow preventer while maintaining compatibility with various installation configurations and heights.

[0010] The preferred embodiment provides a cost-effective solution, compared to the replacement cost of stolen backflow preventers. Various embodiments of the invention is particularly valuable for protecting installations in public spaces where theft is prevalent.BRIEF DESCRIPTION OF THE FIGURES

[0011] FIG. 1 illustrates a front perspective view of an embodiment of the invention showing the protective cage and flange components.

[0012] FIG. 2 shows a top down view of an embodiment of the invention depicting the arrangement of the flanges and lock assembly within the protective cage.

[0013] FIG. 3 depicts the flange components prior to installation upon the cage in anembodiment.

[0014] FIG. 4 depicts a detailed view of an embodiment of the invention showing the steel bar component comprising a T-catch and claw catch.DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the invention provides a cost-effective solution to prevent the theft of backflow preventers, addressing a significant problem faced by municipalities, businesses, and property owners. The preferred embodiment of the invention can be installed directly in the field and is adaptable to various backflow preventer configurations, as these devices often differ in their height from the ground.

[0016] The preferred embodiment of the invention utilizes standard-sized components designed to fit typical backflow preventer cage 100 installations. This standardization allows for efficient manufacturing while maintaining broad compatibility across different installation scenarios. An embodiment of the invention involves strategic placement of metal components and specialized bars that work in conjunction with existing protective cages.

[0017] Installation of the preferred embodiment is straightforward and can be performed on-site, requiring only basic modifications to existing protective cages. An embodiment of the invention specifically addresses the vulnerabilities commonly exploited by thieves, incorporating features that protect critical components from common tools used in theft attempts, such as sawzalls and hacksaws.

[0018] The preferred embodiment of the invention can be manufactured for approximately $30, providing a highly cost-effective solution when compared to the $1,400-$ 1,600 replacement cost of a stolen backflow preventer. This economic efficiency makes an embodiment of the invention particularly valuable for large-scale deployments, such as in municipal parks and other public spaces where multiple devices require protection.

[0019] The preferred embodiment of the invention comprises several key components that work together to create an effective anti-theft system. An embodiment of the invention utilizes a modified rebar or 1 / 4" thick steel bar of standard length (approximately 13.75 inches in the preferred embodiment, but in varying embodiments a length of 12 inches-24 inches) as its primary component, which is designed to work in conjunction with existing protective cages.

[0020] The preferred embodiment includes strategically placed steel flanges 210 with rectangular aspects that house specialized catches - specifically, catch mechanisms (such as T-catches 320 or circular-shaped catches) on one side and corresponding claw 310 catches on the opposite side. A critical feature of an embodiment of the invention is its lock protection system, which incorporates square tubing designed to shield the U-part of the lock 200, while the flanges 210 are engineered to prevent access by common cutting tools such as sawzalls or hacksaws. The components are precisely sized and configured to work together, with the hole within the steel being specifically dimensioned to accommodate the bar while maintaining security. These components, when properly installed under the backflow preventer, create an integrated security system that effectively addresses the vulnerabilities commonly exploited by thieves.

[0021] In an embodiment of the invention, the steel bar component comprises a modified rebar or alternatively a 1 / 4" thick steel bar that serves as the primary securing element. The preferred embodiment utilizes a standard length bar measuring approximately 13.75 inches in the preferred embodiment, but in varying embodiments a length of 12 inches-24 inches, which is specifically dimensioned to accommodate standard-sized width protective cages commonly used with backflow preventers.

[0022] The bar component in an embodiment of the invention incorporates specialized catching mechanisms on both ends, as depicted by FIG. 4. On one side, the bar comprises a catch mechanism — illustratively shown as a T-catch 320 — that is designed to engage with the locking mechanism. Alternative catch configurations include a circular-shaped catch, as further described below. The opposite end of the bar includes a claw catch 310 that works in conjunction with the first end catch mechanism (whether T-shaped or circular-shaped) to secure the assembly.

[0023] While the illustrated embodiment depicts the catch mechanism at the first end of the bar 300 as a T-shaped catch 320, alternative catch configurations may be employed that achieve the same functional result of engaging with the lock 200 within the protective interior space of the hollow structural tube. In one alternative embodiment, the catch mechanism comprises a circular-shaped catch rather than a T-shaped configuration. The circular-shaped catch may comprise a disc, ring, or cylindrical protrusion extending radially from the bar 300, dimensioned to prevent passage back through the bar-receiving aperture once the bar has been inserted and the lock engaged.

[0024] The circular-shaped catch provides certain advantages in terms of ease of manufacture, as it may be formed by welding a circular disc or ring to the end of the bar 300, or by forging or machining a circular protrusion as an integral part of the bar. Like the T-shaped catch 320, the circular-shaped catch functions to engage with the padlock shackle and prevent unauthorized removal of the locking bar from the assembly.

[0025] Both the T-shaped and circular-shaped catch configurations share the common functional characteristic of presenting a geometry that is larger in at least one dimension than the diameter or width of the bar 300 itself, such that once the bar is inserted through the flange and the lock is engaged with the catch, the catch cannot be withdrawn back through the bar-receiving aperture. The choice between T-shaped and circular-shaped configurations may depend on manufacturing considerations, aesthetic preferences, or the specific geometry of the padlock to be used.

[0026] The bar is engineered to slide through the flanges 210, with the T-catch 320 and opposite claw catch 310 positioned to prevent unauthorized removal. In the preferred embodiment, the bar's 300 dimensions are precisely calculated to ensure it fits through the hole within a steel flange 210 while maintaining security integrity.

[0027] The configuration of the T-catch 320 in relation to the bar 300 creates a system where the lock 200 becomes engaged within the flange 210, making access to the securing components difficult.

[0028] When properly installed in accordance with an intended method of use, the bar 300 component of an embodiment of the invention extends through holes cut in either side of the protective cage 100, with the steel flanges 210 positioned on both sides to create a secure assembly. This configuration ensures that the bar and associated catching mechanisms work together to prevent unauthorized access or removal of the backflow preventer.

[0029] In an embodiment of the invention, the flange components comprise steel flanges 210 that are rectangular in aspect as depicted by FIG. 1, designed to be mounted on either side of the protective cage 100. The preferred embodiment incorporates flanges 210 that are precisely engineered with holes sized specifically to accommodate the bar 300, comprising a steel bar or modified rebar component.

[0030] The hole within each steel flange 210 in an embodiment of the invention is dimensioned to be just large enough to allow the bar 300 to pass through while maintaining security integrity in accordance with an embodiment. This precise sizing is critical to the preferred embodiment's security features, as it works in conjunction with the bar 300 to create a secure assembly that prevents unauthorized access.

[0031] A critical aspect of the preferred embodiment is the construction of the first flange 210 as an integrated, unitary component that combines both mounting and lock-protection functions in accordance with an embodiment. Unlike prior art solutions that employ separate mounting plates and add-on shroud components, the first flange 210 of the present invention comprises a planar mounting plate integrally affixed to a hollow structural tube having a rectangular cross-section. This integral construction provides several unexpected advantages over modular approaches.

[0032] The planar mounting plate portion of the first flange 210 is configured to be affixed to an exterior surface of the protective cage 100, and defines a first bar-receiving aperture dimensioned to receive the steel bar 300 in accordance with an embodiment. The hollow structural tube portion, which forms the square tubing previously described, is permanently affixed to the mounting plate and defines an interior space specifically sized and configured to fully enclose the U-part of a padlock when the padlock is engaged with the steel bar 300 within the hollow structural tube in accordance with an embodiment.

[0033] The hollow structural tube defines a second bar-receiving aperture that is precisely aligned with the first bar-receiving aperture in the mounting plate in accordance with an embodiment. This alignment ensures that the locking bar 300 may pass through both the mounting plate and the hollow structural tube in a single, continuous path, creating a secure assembly where the padlock becomes trapped within the protective interior space of the hollow tube.

[0034] In the preferred embodiment, the integral construction of the first flange 210 is achieved through welding the hollow structural tube to the mounting plate, though alternative fabrication methods including casting as a single piece, brazing, or mechanical fastening with reinforcement may be employed. The key aspect is that the hollow structural tube and mounting plate function as a single structural unit that cannot be disassembled in the field without destroying the component.

[0035] The dimensions of the interior space within the hollow structural tube are specifically calculated to accommodate standard padlock geometries while providing minimal clearance in accordance with an embodiment. In one embodiment, the interior space measures approximately 2 inches x 2 inches x 3 inches, sufficient to enclose the U-shaped shackle portion of a standard 2-inch padlock. The walls of the hollow structural tube are preferably fabricated from steel of at least 1 / 8 inch thickness, providing substantial resistance to cutting tools such as sawzalls, hacksaws, and angle grinders. In certain embodiments, the walls may be 1 / 4 inch or greater in thickness for enhanced security.

[0036] A key feature of an embodiment of the invention is the square tubing design incorporated into the flange components. This square tubing is specifically engineered to protect the U-part of the lock 200 from tampering or cutting attempts. The preferred embodiment positions the square tubing so that when the lock 200 is installed, its vulnerable components are shielded within the flange 210 structure, making it difficult for potential thieves to access the lock 200 with common cutting tools such as sawzalls or hacksaws.

[0037] The flange components in an embodiment of the invention are designed to work together as an integrated system, with the steel flanges 210 being placed on either side of the cage 100 after holes are cut for installation. This configuration ensures that the bar 300 can be run through the assembly while maintaining the protective features of the square tubing and the precisely sized holes.

[0038] In an embodiment of the invention, the lock 200 component is specifically designed to integrate with the flange 210 assembly to create a secure anti -theft system. The preferred embodiment comprises or otherwise is designed to accomodate a lock 200 that is dimensioned to fit within the flange structure, where it engages with the bar 300 component's T-catch 320 to create a secure connection.

[0039] The lock 200 in an embodiment of the invention is positioned so that when installed, it fits over the bar 300 and engages with the T-catch 320, preventing unauthorized removal. The preferred embodiment's configuration ensures that if someone attempts to tamper with the lock 200, the T-catch 320 prevent it from being pulled through.

[0040] A critical security feature of an embodiment of the invention is the configuration that protects the lock 200 from tampering attempts. The U-part of the lock 200 is specificallyprotected by square tubing, making it difficult to access the lock 200 for removal. The preferred embodiment positions the lock 200 within the flange 210 assembly in such a way that common cutting tools, including sawzalls and hacksaws, cannot effectively reach the lock 200 due to the protective flange configuration.

[0041] The protective function of the square tubing incorporated into the first flange 210 depends critically on specific dimensional relationships between the hollow structural tube, the padlock 200, and the steel bar 300 in accordance with an embodiment. When the assembly is properly configured, the U-part of the padlock 200 resides entirely within the interior space of the hollow structural tube, with all portions of the padlock shackle positioned at least 1 / 2 inch inward from any exterior opening of the tube.

[0042] The second bar-receiving aperture in the hollow structural tube is positioned such that when the steel bar 300 passes through it, the bar's T-catch 320 engages with the padlock 200 at a location deep within the interior space of the tube in accordance with an embodiment. This positioning ensures that any attempt to access the padlock shackle with cutting tools would require the tools to penetrate through the walls of the hollow structural tube itself, rather than being able to access the shackle through any opening in the tube.

[0043] In the preferred embodiment, the hollow structural tube extends outward from the mounting plate by a distance of at least 3 inches, creating a shrouded channel through which the steel bar 300 passes. This extension length is specifically selected to ensure that the padlock 200, when engaged with the T-catch 320, sits at a depth within the tube that prevents any direct line-of-sight access to the padlock shackle from outside the assembly.

[0044] When properly installed in an embodiment of the invention, the lock 200 component works in conjunction with the bar 300 and flange 210 assembly to create an integrated security system. The configuration ensures that the lock 200 is protected within the assembly while maintaining its functionality, as the U part of the lock 200 remains shielded by the square tubing so that no one can access it to remove the lock 200 from its secured position.

[0045] In an embodiment of the invention, the protective features include a specialized flange design engineered to prevent access to the lock 200 by common cutting tools. The preferred embodiment incorporates flanges 210 that shield the lock 200 from sawzalls and hacksaws, making unauthorized removal attempts significantly more difficult.

[0046] A distinguishing feature of the present invention is its design as a retrofit kit specifically engineered for application to existing protective cages 100 that are already deployed in the field in accordance with an embodiment. Unlike complete enclosure replacement systems, the present invention provides a security upgrade that can be installed without removing or replacing the existing protective cage structure.

[0047] The retrofit nature of the invention is evidenced by the installation method, which necessarily begins with the step of cutting holes in opposite sides of a pre-existing protective cage 100 in accordance with an embodiment. The dimensions and positioning of these holes are specifically designed to accommodate the first flange 210 and second flange 210 such that, when installed, the flanges lie flush against the exterior surfaces of the existing cage.

[0048] The steel bar 300 length (12-24 inches, preferably 13.75 inches) is specifically selected to span the standard widths of commercially available backflow preventer cages, which typically range from 12 to 18 inches in width in accordance with an embodiment. This standardization allows the same kit components to be used across a wide variety of existing cage installations without requiring custom fabrication for each site.

[0049] The second flange 210, in contrast to the first flange 210, may be constructed as a simpler mounting plate without the integrated hollow structural tube, as the lock protection function is fully provided by the first flange 210 in accordance with an embodiment. However, in alternative embodiments, both flanges may incorporate the integrated hollow tube construction to provide redundant security features or to accommodate different locking configurations.

[0050] The configuration of an embodiment of the invention creates a secure assembly where both the bar 300 and lock 200 are deliberately positioned to be difficult to access. The preferred embodiment achieves this through strategic placement of components, where the bar 300 slides through the assembly and the lock 200 becomes engaged within the flange 210 in a way that limits physical access to these critical securing elements.

[0051] An embodiment of the invention includes metal components that are specifically installed under the backflow preventer. The preferred embodiment's installation process involves strategic placement of these metal components, with the flanges 210 being mounted on either side of the protective cage 100 after appropriate holes are cut. This configuration ensuresthat the entire assembly works together to create an integrated security system that protects the backflow preventer from theft attempts.

[0052] The protective features in an embodiment of the invention work in conjunction with the existing cage 100 structure, creating multiple layers of security. When properly installed, the preferred embodiment's protective elements ensure that the U part of the lock 200 remains shielded by the square tubing, the bar 300 is securely positioned through the assembly, and the entire configuration is protected from common theft techniques.

[0053] In an embodiment of the invention, the components are specifically engineered to integrate with standard protective cages that commonly surround backflow preventers. The preferred embodiment's installation process begins with cutting two holes in either side of the existing protective cage 100 to accommodate the security assembly. The standard length bar 300 in an embodiment of the invention (approximately 13.75 inches in the preferred embodiment, but in varying embodiments a length of 12 inches-24 inches) is specifically dimensioned to work with standard-sized width protective cages, ensuring broad compatibility across different installations.

[0054] The preferred embodiment accounts for variations in backflow preventer configurations, particularly the different heights at which these devices may be mounted from the ground.

[0055] Installation of an embodiment of the invention involves a systematic process where the steel flanges 210 are placed on either side of the existing cage's 100 newly cut holes. The bar 300 is then run through the assembly, with hooks engaging on one side and extending through the opposite side.

[0056] The preferred embodiment's configuration ensures that when properly installed, the entire assembly works in harmony with the existing cage structure to prevent unauthorized access to the backflow preventer.

[0057] The integrated security features of an embodiment of the invention, including the protected lock assembly and flange configuration, complement the existing cage's protective function. When installed according to the preferred embodiment's specifications, the assembly creates multiple layers of security that work together to prevent theft of these valuable devices.

[0058] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. It is not intended that the invention be limited by the specific examples provided within the specification. While the invention has been described with reference to the aforementioned specification, the descriptions and illustrations of the embodiments herein are not meant to be construed in a limiting sense. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Furthermore, it shall be understood that all aspects of the invention are not limited to the specific depictions, configurations or relative proportions set forth herein which depend upon a variety of conditions and variables. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is therefore contemplated that the invention shall also cover any such alternatives, modifications, variations or equivalents. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

CLAIMSI claim:

1. An anti-theft flange component for a retrofit security system for backflow preventers, said component comprising:a planar mounting plate configured to be affixed to an exterior surface of a protective cage, said mounting plate defining a first bar-receiving aperture;a hollow structural tube having a rectangular cross-section, said hollow structural tube being integrally affixed to said mounting plate and defining an interior space; and wherein said hollow structural tube defines a second bar-receiving aperture aligned with said first bar-receiving aperture, such that a locking bar may pass through said mounting plate and said hollow structural tube; andwherein said interior space is sized and configured to fully enclose a U-part of a padlock when said padlock is engaged with said locking bar within said hollow structural tube, thereby shielding said U-part from cutting tools.

2. The anti-theft flange component of claim 1, wherein said hollow structural tube comprises walls of at least 1 / 8 inch thickness fabricated from steel.

3. The anti-theft flange component of claim 1, wherein said hollow structural tube is integrally affixed to said mounting plate through welding.

4. The anti-theft flange component of claim 1, wherein said second bar-receiving aperture is positioned such that when said locking bar passes through said hollow structural tube, a catch mechanism on said locking bar engages with said padlock at a location within said interior space.

5. The anti -theft flange component of claim 1, wherein said interior space has dimensions of approximately 2 inches x 2 inches x 3 inches.

6. The anti-theft flange component of claim 1, wherein said hollow structural tube extends outward from said mounting plate by at least 3 inches.

7. The anti-theft flange component of claim 1, wherein said mounting plate is rectangular in aspect and configured to align with a hole cut in said protective cage.

8. A retrofit security kit for backflow preventers comprising:a first flange component according to claim 1;a second mounting plate configured to mount on an opposite side of said protective cage from said first flange component; anda steel bar having a length of 12-24 inches, said steel bar configured to pass through said first bar-receiving aperture, through said protective cage, and through said second mounting plate.

9. The retrofit security kit of claim 8, wherein said steel bar comprises:a first end having a catch mechanism configured to engage with said padlock within said interior space of said hollow structural tube; anda second end having a corresponding catch mechanism configured to secure said steel bar to said second mounting plate.

10. The retrofit security kit of claim 8, wherein said steel bar comprises one of:a modified rebar; ora steel bar of at least 1 / 4 inch thickness.

11. The retrofit security kit of claim 8, wherein:said first flange component and said second mounting plate are each configured to be affixed to exterior surfaces of an existing protective cage surrounding a backflow preventer; andsaid steel bar has a length configured to span standard widths of backflow preventer protective cages ranging from 12 to 18 inches.

12. The retrofit security kit of claim 9, wherein:said catch mechanism at said first end comprises a circular shaped or T-shaped catch; and said corresponding catch mechanism at said second end comprises a claw-shaped catch.

13. A method of retrofitting an existing protective cage surrounding a backflow preventer with an anti-theft security system, said method comprising:cutting a first hole in a first side of said existing protective cage;cutting a second hole in a second side of said existing protective cage opposite said first side;affixing to an exterior surface of said first side a flange component comprising:a planar mounting plate defining a first bar-receiving aperture; anda hollow structural tube having a rectangular cross-section integrally affixed to said mounting plate and defining an interior space, said hollow structural tube having a second bar-receiving aperture aligned with said first bar-receiving aperture; affixing to an exterior surface of said second side a mounting plate defining a third barreceiving aperture;inserting a steel bar through said first bar-receiving aperture, through said first hole, through said existing protective cage, through said second hole, through said third barreceiving aperture, and through said second bar-receiving aperture; andsecuring said steel bar with a padlock engaged within said interior space of said hollow structural tube such that a U-part of said padlock is fully enclosed within said interior space and shielded from cutting tools.

14. The method of claim 13, wherein said existing protective cage is a cage of a type commonly used to protect backflow preventers and does not include integrated lock protection features.

15. The method of claim 13, wherein:said steel bar comprises a catch mechanism at a first end; andsaid step of securing comprises engaging said padlock with said catch mechanism at a position within said interior space such that said U-part of said padlock is positioned at least 1 / 2 inch inward from exterior openings of said hollow structural tube.

16. An integrated flange apparatus for securing a locking bar to a protective structure while protecting a locking mechanism, said apparatus comprising:a mounting plate having an exterior mounting surface and an interior surface, said mounting plate defining a through-aperture extending from said exterior mounting surface to said interior surface;a tubular shroud structure integrally connected to said interior surface of said mounting plate, said tubular shroud structure defining:an enclosed chamber dimensioned to receive and fully enclose a shackle portion of a padlock therein; anda bar passage aligned with said through-aperture of said mounting plate and configured to permit a locking bar to pass therethrough into said enclosed chamber; and wherein said tubular shroud structure is configured such that when said locking bar passes through said bar passage and engages with said padlock within said enclosed chamber, said shackle portion of said padlock is inaccessible to cutting tools from outside said enclosed chamber.

17. The apparatus of claim 16, wherein said tubular shroud structure comprises:four walls arranged to form a rectangular cross-section; andsaid walls having a thickness of at least 1 / 4 inch.

18. The apparatus of claim 16, wherein said tubular shroud structure and said mounting plate are fabricated as a unitary welded assembly.

19. The apparatus of claim 16, wherein said enclosed chamber has dimensions selected to accommodate a standard 2-inch padlock with minimal clearance.

20. The apparatus of claim 16, wherein said apparatus is configured for retrofit installation onto an existing protective cage by:aligning said exterior mounting surface with a hole cut in said existing protective cage; andaffixing said mounting plate to an exterior surface of said existing protective cage such that said through-aperture aligns with said hole.

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