The invention disclosure relates a flexible, disposable piece of emergency duty personnel kit deployable to reliably disable locks and latches on doors and gates in dangerous conditions.
First responders, including law enforcement officers, parole officers, probation officers, firefighters, paramedics, EMTs and EMS workers frequently encounter an unknown locking or lockable gate or door. To secure their own exit, and to assure that other first responders can follow, they often have to search, in the dark and in a hurry, to find something to block the door open and prevent any locking mechanisms on the door from engaging. Actual common improvised door blocking mechanisms include jamming wadded up paper into the strike plate hole, stuffing a business card into the lock, strips of duct tape pre-disposed on a flashlight handle, or hoping to find a trash can, a rug, or a brick to simply prop the door open.
Improvised door-blocking mechanisms take away critical time needed to render aid on any emergency call. They are too often removed by passers-by, fail due to environmental conditions or simply fall out of place unnoticed when the next officer opens the door.
What is needed is a first responder's tool for quickly disabling all sorts of door and gate locking mechanisms and preventing doors and gates from closing behind them. Because first responders are already burdened with tools, it should be light, fit in almost any pocket and be deployable in seconds. It must be weatherproof and chemical resistant. It should be tough, reliable and reusable but also, ideally, economical and disposable, since such a tool will often get left behind during emergencies.
A Disposable Emergency Duty Latch Disabling Strip having, in combination, length and elasticity enough to fit around almost any door jamb security mechanism is made of a thin, tough elastomer. A first rounded end portion with a handle-adaptive hole fits around a door knob, handle or lever on one side of the door. A latch-enveloping middle portion of the Disposable Emergency Duty Latch Disabling Strip has, in combination, width and puncture strength enough to cover a door's latch-bolt and strike plate or other latching portion and restrain any spring-bolts or latches from engaging. The remaining handle-adaptive end portion of the Strip wraps around to the far side of the lockable door and is attached to the far side door mechanisms using the remaining handle-adaptive hole. Depending on door tolerances, the door will either wedge open or the lock will be prevented from engaging. The Disposable Emergency Duty Latch Disabling Strip is thin, flexible and can be folded or rolled to deploy from a pocket, belt pouch, clasp or dispenser.
The thick rubber of the device of
The elastic material used in the Disposable Emergency Duty Latch Disabling Strip can be any elastomer capable of being manufactured to the specifications in this disclosure and used to prevent a door from locking according to the methods described in this disclosure.
Elastomers that are possible include solid neoprene, natural gum rubber, silicone and latex. The elastomer type is not critical to the product, so long as it falls within most or all of the specifications.
Gum rubber and solid neoprene, in particular, have been found to be manufacturable both to meet the specifications of this disclosure and for economy. Natural gum rubber can suffice for police applications, for example, since it withstands temperate ranges between 212 F to −20 F and can be manufactured inexpensively.
For firefighter applications, an elastic silicone strip can be preferable. Molding and curing of silicone can be more expensive than gum rubber, and silicone can have poorer elastic properties at moderate temperatures than gum rubber, necessitating more material. However, at extreme temperatures, silicone rubber is more durable than gum rubber. Typical silicone rubbers can function to arrest door latches in this application at temperatures as high as 572 degrees Fahrenheit and as low as −178 degrees Fahrenheit.
Some silicone rubber gasket materials can intermittently stand temperatures up to 650 Fahrenheit. Other silicone rubbers specially formulated for extreme temperatures, such as Resbond Fireproof, can survive up 2350 degrees Fahrenheit. This application contemplates use of such high temperature elastomers in cases where they also exhibit sufficient tensile strength to resist tearing and sufficient hardness at ⅛ inch thickness to arrest a fifteen-pound spring-bolt.
In terms of tensile strength, even the weaker silicones such as Room Temperature Vulcanize exhibit strength of 800 psi or more and can be made to have elasticity of up to 370%. Others, such as Fluorosilicone Rubber and High Consistency Rubber, can have much higher tensile strength and elasticity.
By matter of contrast, foam or closed-cell neoprene has not been found to be usable in the door-latch disabling application of the Strip because it lacks the tear strength or puncture resistance to reliably impede spring-bolts. Similarly, an elasticized cloth material such as Spandex would likely be usable only if it is a latch-adaptive elasticized cloth material made thick enough to arrest a latch-bolt and to wedge a doorjamb, and if it is not used for firefighter applications where the cloth matrix would catch fire.
And, a non-elastic material is not workable in this application due to the versatility of door locks, gate locks, window locks and security device configurations encountered by emergency personnel.
It is noted that the latch-enveloping middle portion is at least as wide as the two handle-adaptive end portions. In the preferred embodiment, the Disposable Emergency Duty Latch Disabling Strip has a width of three inches. The three inch width allows the latch-enveloping middle portion to cover and restrain the latch-bolt of various configurations found in gates and doors in commercial, industrial and residential applications where a latch-bolt might be offset from the doorknobs or levers. A 20% width variance in either direction is functional but not preferred, so the latch-enveloping middle portion can be from 2.4 to 3.6 inches wide.
Note that an alternate embodiment can give the latch-enveloping middle portion greater latch-engaging width by cutting the Strip in an oval shape, with the latch-enveloping middle portion increasing to a middle width greater than the two handle-adaptive end portion widths.
In the preferred embodiment, the Strip has a ten inch length at rest-when not being stretched. This, along with the elasticity, allows it to wrap around most door edges, handles, locking mechanisms, keypads and any other installed security devices or features of the door. A 20% length variance in either direction is functional but not preferred, so the Strip can be from 8 to 12 inches in length.
Also in the preferred embodiment, the handle-adaptive end portions have handle-adaptive through-holes one and one quarter inch, or five-quarter inches, in diameter. This size handle-adaptive hole, combined with the elongation properties of the elastomer, allows for the handle-adaptive end portions to be stretched and slipped over most knobs, handles, levers and other mechanisms used to open doors. A 20% diameter variance in either direction is functional but not preferred, so the handle-adaptive holes may be between one and one-and-one-half inch. The handle-adaptive through-holes have an edge of elastomeric material which may also be called a perimeter.
In the case of through-holes that are not circular, at least one perimeter edge or diagonal should be between one and one & one-half inch. Further, the handle-adaptive holes allow for the Strip to be wrapped through itself when tied around a door handle without a knob or lever, and secured when otherwise adapted to unusual door configurations. Here, a standard door handle may be defined as any of a knob, handle, lever, door-pull, U-bar, push-bar, extruded lock, combination lock panel, or other commonly manufactured door opening, locking or pulling mechanism and capable of having a strip of elastic material tied, wrapped or adhered to it.
Due to manufacturing variances, and because the Strip is elastic, some variation in width of the latch-enveloping middle portion, length of the Strip, size of the handle-adaptive through-holes, and in other measurements is possible. However, because the Strip must resist breaking, abrading and tearing in cold, in heat, in emergency situations and with a wide range of door configurations, dimensions and tolerances of less than eighty percent those described in regard to the preferred embodiment can not be considered reliable.
The elastomer of the Strip in the preferred embodiment is capable of a minimum elongation (tip to tip) of three times or three-hundred percent (300%). This elongation property is important so that the Strip has a compact form in its relaxed state to carry discreetly in a compact storage compartment. A 20% elasticity variance is functional but not preferred, so the Strip elastomer material must have an elasticity of at least 240%. Thus, the stretch length in a Strip having a 10 inch rest length and 300% elasticity of the preferred embodiment will be 30 inches. The stretch length in an alternate embodiment Strip having an 8 inch rest length and 240% elasticity will be 19.2 inches. Different sizes and elongations may be manufactured for regions with different building practices.
It is also preferred that the elongation property be under 360%, in order to retain deformation resistance. Elongation also allows the Strip to relax short or stretch long, thus giving the range of differences in reach needed to wrap around numerous types of doors and gates with or without security features that increase the effective distance from one side of the door to the other. In contrast, a Strip of strong, flexible plastic without the ability to elongate would need to be approximately thirty inches in length to wrap around the effective distances from one side of a door to the other. Such a long Strip would need to be laboriously wrapped and knotted for shorter effective distances, and would be subject to tangling, making for a less desirable embodiment of the invention.
The material of the Strip at its given thickness must be capable of resisting tearing as it elongates. Thus, the Strip should have a tensile strength of seven hundred pounds per square inch (700 PSI) in the preferred embodiment. This strength is important so a user will not inadvertently tear the product by applying too much pressure using human force alone. A 20% variance in tensile strength is functional but not preferred, so a minimum tensile strength of 560 pounds per square inch (560 PSI). A stretch strength of at least 560 PSI allows the product to withstand most stresses and door configurations.
Finally, the partially bent shape of the Strip in
Testing has shown that the invention must, therefore, be made of elastic material with a durometer of at least 36, and at most 54, according to the Shore A hardness test. In the preferred embodiment, the Emergency Duty Latch Disabling Strip has a durometer of 45, with an allowable variation of plus or minus 20% according to the Shore A hardness test (45 Shore A, +/−5). This degree of hardness allows the Strip to successfully restrain a 15-pound spring-bolt, which is the maximum spring-bolt force typically used in light of disability concerns.
For the purpose of claiming the invention, an adjacent door edge may be defined as the long edge of a door opposite the hinged edge and containing the locking mechanism allowing a locking bolt to interface with a strike-plate when the door is shut and the adjacent door edge is flush with the door jamb. Such adjacent edge will therefore also typically be adjacent any standard door handle.
As noted above, the Strip is flexible and foldable. Thus, a first-responder or other user can add the Strip to his equipment by folding or rolling one or more Emergency Duty Latch Disabling Strips into a compact shape and fitting them into a pocket or belt pouch. One or more Strips can also be hooked onto a belt, buckle, snap, clasp or hook through the handle-adaptive holes of the end portions, or even temporarily tied around a belt, belt loop or even an arm by pulling one end through the handle-adaptive hole of the opposite end. In some cases, multiple Strips will be packaged pre-folded in a box or dispenser that can be carried in a vehicle, backpack or large pocket.
When the user encounters a lockable door that he intends to prevent from becoming locked, so as to maintain entry during emergency situations, the Strip is quickly deployed with the primary goal of preventing spring-bolt or dead-bolt locks in the door from engaging. The user fits one of the handle-adaptive holes around one door knob, handle or lever, just as a handle-adaptive hole 5 is shown fitted around the round door-knob 12 of
If a spring-bolt is present, the latch-enveloping middle portion can undergo some deformation; the user checks that the latch-enveloping middle portion is effectively restraining the spring-bolt from locking the door. The user fits the remaining handle-adaptive hole around the knob, lever or other appropriate feature on the other side of the door, stretching the Strip if necessary.
If the Strip is, at this point, loose or hanging or the user simply wants to tighten the Strip to discourage removal, he can wrap, wind, twist or knot one handle-adaptive end portion around a door knob or lever before fitting the handle-adaptive hole over the knob. Alternatively, he can wrap one handle-adaptive end portion around the knob before tightening by pulling the other end portion back through its handle-adaptive hole.
In the same manner, door handles such as push-bars, door-pulls, U-bars, large keypads and others that cannot be dealt with by fitting a handle-adaptive through-hole over an extrusion can, instead, be handle by tying. The user loops a first end portion of the flat elastomer strip around such a door handle and then pulls the other end portion through the through-hole of the first end portion, making a closed loop around the handle.
Note that the overlapping type of double-door depicted in
Other users may prefer the Emergency Duty Latch Disabling Strip to have bright high-visibility coloring to alert other emergency responders, or even printed patterns or warnings to dissuade bypassers. Particular colors or markings of the Strip can even be matched to particular users or agencies to indicate to follow-on responders who the Strip was placed by.
One embodiment of the Strip specialized for use by firefighters incorporates a photoluminescent additive to the elastomer which makes the Strip produce a visible glow in hot, smoke-filled buildings. This aids a firefighter in visually locating the door through which he entered, and support personnel in following his path.
A device middle portion width matching the diameter of the spring-bolt latch would slip from and fail to arrest an off-center latch mechanism of the type depicted. Instead, the latch-enveloping middle portion of the invention, being at least as wide as the two handle-adaptive end portions, easily spans the vertical difference between the latch mechanism and door handles, entirely covers the latch-bolt hole, restrains the latch bolt elastically, and leaves unstretched portions of elastomer extending around the edges of the latch bolt wedgable into the strike plate.
The remaining handle-adaptive end portion of the Strip wraps around to the far side of the depicted door and is attached to the far side door mechanisms using the remaining handle-adaptive hole according to one of the methods described above. Because of the design of the latch-enveloping middle portion of the Strip, the far side door mechanisms can also be vertically off-center, upward or downward, from the latch-bolt mechanism with no degradation in latch-arresting performance by the invention.
Because the invention is often deployed in rugged outdoor environments, direct sunlight, industrial facilities, warehouses and chemical storage, or during structure fire emergencies, the surface temperature of doors and door hardware can reach high temperatures. Therefore, Emergency Duty Latch Disabling Strip uses elastomer materials rated to withstand heat up to two-hundred and twelve degrees Fahrenheit (212 F). It must also be able to withstand cold as low as negative 20 degrees Fahrenheit (−20 F) without becoming brittle or breaking in use.
In an alternate embodiment, the Emergency Duty Latch Disabling Strip is made in a one-use format. The Strip is disposed with a one-use adhesive portion protected by a sticker backing or plastic baggy. The adhesive portion adheres the Strip to itself or to the door, making removal difficult without tearing. This one-use format can be used in areas where passers-by have a tendency to remove or reuse the Strips, or to aid in preserving the chain of events for later evidentiary reporting. For evidentiary purpose, an alternate embodiment may also be pre-markable with identifying information.
Although the present invention has been described in connection with certain specific embodiments for instructional purposes, the present invention is not limited thereto. Accordingly, various modifications, adaptations, and combinations of various features of the described embodiments can be practiced without departing from the scope of the invention.
This application claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application No. 62/539,461, entitled “DISPOSABLE EMERGENCY DUTY LATCH DISABLING STRIP”, filed 31 Jul. 2017, which is incorporated by reference for all purposes.
Number | Date | Country | |
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62539461 | Jul 2017 | US |