The present invention relates to security systems for preventing forced entry of doors and other structures and, in particular, to cut-resistant security systems.
Residential and non-residential burglaries cost billions of dollars in property losses each year. The majority of burglary offenses involve forcible entry or attempted forcible entry. Common methods of forced entry include cutting, prying and drilling. In particular, power cutting tools have increased the risk and vulnerability to break-ins. Modern grinders, reciprocating saws, and circular saws are battery operated, lightweight and easily portable, and are relatively inexpensive and readily available. Such tools are designed to cut through any material, including metal and concrete, and can quickly and easily compromise conventional security doors, security cabinets, safes and other reinforced structures.
Commercial doors are commonly reinforced with steel plates or bars. However, such passive security devices may not be sufficient to protect against power cutting tools. Active anti-cut security devices include compression bar systems, which generally comprise a metal rod that is placed under longitudinal compression by a spring positioned at the end of the rod. The rod and spring are secured within a casing that prevents the lateral movement of the components and maintains the compression of the rod. When the rod is cut transversely, the spring forces the cut ends of the rod together against the sides of the blade to act as a clamp and arrest further movement of the blade (e.g., similar to the operation of a disc brake). When the blade is withdrawn, the spring forces the cut ends of the rod back together to heal the cut, which allows the compression bar to resist multiple cutting attempts.
Compression bar systems have potential weaknesses. For example, modern high-speed cutting tools can generate frictional heat that approaches the melting temperature of metal, and can inadvertently weld the casing to the compression rod. Once the compression rod is welded to the casing, the spring can no longer force the cut ends of the rod together to clamp the cutting blade or heal the cut. In addition, the compression bar system may be vulnerable to cutting through the spring. Therefore, it would be desirable to develop active security systems that can protect against modern cutting tools.
In an embodiment, a security device comprises a hollow casing having an interior space with a longitudinal axis. A plurality of rods and a plurality springs are positioned in the interior space, including first and second rods and first and second springs. The first rod extends parallel to the longitudinal axis, the first spring is positioned to exert compressive force on the first rod in a direction parallel to the longitudinal axis, the second rod is positioned parallel to the first rod, and the second spring is positioned to exert compressive force on the second rod in a direction parallel to the longitudinal axis. The plurality of springs does not include two springs that overlap with respect to a plane perpendicular to the longitudinal axis. In an embodiment, the interior space has an inner surface, the first rod has a polygonal cross-section with first polygon vertices, and the second rod has a polygonal cross-section with second polygon vertices. The first rod contacts the inner surface only at the first polygon vertices, and the second rod contacts the inner surface only at the second polygon vertices. In an embodiment, the interior space comprises first and second lobes that form an inner surface having a cross-section defined by two overlapping circles. The first rod and first spring are positioned in the first lobe, and the second rod and second spring are positioned the second lobe.
In one embodiment, a security system for a door comprises first and second security bars coupled to the door. The first security bar comprises a hollow first casing having a first interior space with a first longitudinal axis. A first rod and a first spring are positioned in the first interior space, the first rod extending parallel to the first longitudinal axis, and the first spring positioned to exert compressive force on the first rod in a direction parallel to the first longitudinal axis. The second security bar comprises a hollow second casing having a second interior space with a second longitudinal axis. A second rod and a second spring are positioned in the second interior space, the second rod extending parallel to the second longitudinal axis, and the second spring positioned to exert compressive force on the second rod in a direction parallel to the second longitudinal axis. The first and second longitudinal axes are substantially horizontal to the door, and the first and second springs do not overlap with respect to a plane vertical to the door. In an embodiment, the door is hollow and has a door interior space. The first and second security bars are positioned in the door interior space. In an embodiment, the security system further comprises first and second brackets coupled to the door and extending into the door interior space. The first security bar is positioned in the door interior space on the first bracket, and second security bar is positioned in the door interior space on the second bracket.
In one embodiment, a security system for a door comprises first and second security bars, and a hinge bracket coupled to the door. The door has inner and outer sides, and a first end hingedly coupled to a frame. The door has a closed position wherein the door is disposed in the frame with a first space between the first end and the frame. The first security bar comprises a hollow first casing having a first interior space with a first longitudinal axis. A first rod and a first spring are positioned in the first interior space, the first rod extending parallel to the first longitudinal axis, and the first spring positioned to exert compressive force on the first rod in a direction parallel to the first longitudinal axis. The second security bar comprises a hollow second casing having a second interior space with a second longitudinal axis. A second rod and a second spring are positioned in the second interior space, the second rod extending parallel to the second longitudinal axis, and the second spring positioned to exert compressive force on the second rod in a direction parallel to the second longitudinal axis. The first and second longitudinal axes are substantially horizontal to the door, and the first and second springs do not overlap with respect to a plane vertical to the door. The door has inner and outer sides, and a first end hingedly coupled to a frame, the door having a closed position wherein the door is disposed in the frame with a first space between the first end and the frame. The hinge bracket comprises a frame leaf and a door leaf rotatably coupled by a pin. The frame leaf is secured to the frame, and the door leaf is secured to the first end of the door. The hinge bracket extends across the first space. In an embodiment, the door leaf extends from the first end to the inner side of the door. In an embodiment, the door leaf conforms to the first end and inner side of the door. In an embodiment, the security system further comprises a first plate secured to the inner side of the door.
In one embodiment, a security system comprises a rolling door and a security bar. The rolling door comprises a slat having a body with an inner and outer side. The body includes a channel opening toward the inner side. The security bar is sized and shaped to fit within the channel, and comprises a hollow casing having an interior space with a longitudinal axis. A plurality of rods and a plurality springs are positioned in the interior space, including first and second rods and first and second springs. The first rod extends parallel to the longitudinal axis, the first spring is positioned to exert compressive force on the first rod in a direction parallel to the longitudinal axis, the second rod is positioned parallel to the first rod, and the second spring is positioned to exert compressive force on the second rod in a direction parallel to the longitudinal axis. The plurality of springs does not include two springs that overlap with respect to a plane perpendicular to the longitudinal axis.
Referring to
As best shown in
As best shown in
Those of skill in the art will appreciate that other configurations may be used to limit the contact between the compression rod and casing, and/or between two parallel rods. For example, separately formed spacers may be inserted between the rods and/or casing. However, it is generally desirable to maximize the thickness of the rod relative to the interior space of the casing, to increase resistance to cutting. It is also desirable to reduce the complexity of the shapes to reduce manufacturing costs. In a preferred embodiment, the compression rod has a hexagonal cross-section and the casing has an inner surface that forms an interior space with a circular cross-section.
The compression rod may be made of a variety of cut-resistant materials, including various metals, porcelain, ceramics, and abrasive materials as are known in the art. In a preferred embodiment, the compression rod is made of hardened steel. The casing may be made of the same or different material as the compression rod. In a preferred embodiment, the casing and compression rod are made of different metals. Because the compression bar primarily relies on the compression rod to resist cutting, the casing may be made of metals that are easier to machine or extrude to form the interior space. For example, the compression rod may be made of hardened steel and the casing may be made of aluminum.
Compression bar 100 has a length that substantially spans the width of a standard door (i.e. about 36 inches), and may be slightly shorter than the width of the door to allow retrofit installation of existing doors. In a preferred embodiment, cylindrical tube 106 has a length of about 35 inches, with an outer diameter of about 0.75 inches and an interior diameter of about 0.583 inches defining interior space 106a. Rod 102 has a length of about 28.125 inches and a hexagonal cross-section with a distance of about 12 mm across flats (i.e. perpendicular distance between opposite sides of the hexagon). The difference between the distance across corners of hexagonal rod 102 (i.e. between opposite vertices) and the diameter of interior space 106a is preferably about 1 mm or less.
It is generally desirable that the compression bar is able to maintain compression and self-heal after at least 10 cutting attempts, which would allow the compression bar to withstand an attack for half an hour or more. Those of skill in the art will appreciate that the effectiveness of the compression bar system depends in part on the force exerted and degree of travel provided by the compression springs 104. Each cutting attempt removes material from rod 102 and reduces the compression on the rod. In general, longer springs 104 with greater travel increase the ability to maintain compression of rod 102 over multiple cuts. However, a longer spring 104 also increases the risk that a cut will be made through the spring rather than the rod, and increases the vulnerability of the compression bar.
In a preferred embodiment, compression springs 104 have a diameter of about 0.5 inches, a free length of about 4 inches, a fully compressed or solid height of about 2.94 inches, and a spring rate of about 348 lbs/in. The total length of rod 102 and springs 104 is about 36.125 inches. End plugs 110 are cylindrically-shaped with a diameter of about 0.563 inches and a length of about 0.5 inches, and are positioned within interior space 106a flush with the ends of tube 106. The length of interior space 106a between end plugs 110 is only about 34 inches, such that springs 104 are compressed to about their solid height and places rod 102 under longitudinal compression.
In a preferred embodiment, single-rod compression bars 100 and 150 are used in combination. As best shown in
It is also preferred to secure a single-rod compression bar to a door or other structure at both ends. When a compression rod is cut, the casing ensures that the cut ends are aligned to allow self-healing of the cut ends and maintain compression on the rod. If the casing is also cut through, the cut ends of the casing may shift and prevent the proper alignment of the compression rod to self-heal and maintain compression. Therefore, it is desirable to secure both ends of the casing to prevent shifting in the event the casing is cut through.
The need to secure both ends of the case is reduced in compression bars that contain two or more compression rods that are positioned closely together. As a cutting tool begins to cut through the compression bar, the first compression rod will stop or slow the tool to prevent it from cutting through the adjacent compression rod(s). As a result, the tool cannot cut through the casing, which ensures the proper alignment of the compression rods to self-heal and maintain compression.
The first and second compression rod assemblies are positioned closely together within the interior space 206a of hollow casing 206. Interior space 206a has a bilobed cross-section formed by two marginally overlapping circles. As best shown in
In a preferred embodiment, rods 202a and 202b, and springs 204 have the same configurations and dimensions as rods 102 and 152, and springs 104. Casing 206 has a length of about 35 inches, with an interior space 206a that has a cross-section formed by two marginally overlapping circles with diameters of about 0.583 inches and a spacing of about 0.551 inches on center. The first and second compression rod assemblies are held apart, and have minimal or only point contact with each other within interior space 206a. End plugs 208 also have a bilobed-shape formed by two circles having outside diameters of 0.556 inches with a spacing of 0.551 inches on center, and a length of about 0.375 inches. End plugs 208 are positioned within interior space 206a flush with the ends of tube 206, such that the length of interior space 206a between the end plugs is only about 34.25 inches. Those of skill in the art will appreciate that interior space 206a may also be formed as separate circles, such that there is no contact between the first and second compression rod assemblies. However, this configuration may increase the size of the casing.
It is preferable that the compression springs are at their solid height and are fully compressed to maximize their compressive force and amount of throw available for self-healing. In one embodiment, the compression of the springs is adjustable to compensate for variations in manufacturing and assembly. Each lobe of end plugs 208 has a threaded hole 208b for receiving set screws 212 to adjust the compression. As set screws 212 are tightened and screwed through holes 208b, they come into contact with a spring 204 of the first compression rod assembly or a rod 202b of the second compression rod assembly, and effectively reduce the length of the interior space and compress springs 204. A flat headed pin 214 may be inserted in the opening of spring 204 to provide a bearing surface for the set screw 212. For example, a compression bar may be assembled with the springs at about 90% compression, and the set screws tightened to fully compress the springs.
In one embodiment, compression bar 200 may be attached to an existing structure (e.g., a door, cabinet or safe) to provide reinforcement and anti-cut protection. Various means of attachment may be used as are known in the art, including adhesives, welding, and fasteners such as rivets, bolts and screws. In a preferred embodiment, casing 206 has flanges 216 for attachment of a fastener or to provide additional surface area for an adhesive.
The compression rod assemblies are positioned within the interior space 306a of hollow casing 306. Interior space 306a has a trilobed cross-section formed by three marginally overlapping circles. As best shown in
Similarly to end plugs 208, each lobe of end plugs 308 may have a threaded hole 308b for receiving set screws 312 to adjust the compression. As set screws 312 are screwed through holes 308b, they come into contact with a spring 304 of the first compression rod assembly or a rod 302b or 302c of the second and third compression rod assemblies, to increase the compression. A flat headed pin 314 may be inserted in the opening of spring 304 to provide a bearing surface for the set screw 312.
In a preferred embodiment, rods 302a and 302b, and springs 304 have the same configurations and dimensions as rods 102 and 152, and springs 104. Rods 302c and 302d have the same configuration and dimensions as rod 152, except that rod 302c has a length that is about half the length of rod 302b. For example, rods 302c may each have a length of about 7.125 inches. Casing 306 is cylindrical with an outer diameter of about 1.338 inches and a length of about 35 inches. Interior space 306a is similar to interior space 206a, and has a cross-section formed by three circles with diameters of about 0.583 inches and an equilateral spacing of about 0.549 inches on center. Because the circles are only marginally overlapping, the first, second and third compression rod assemblies are held apart, and have minimal or only point contact with each other within interior space 306a. End plugs 308 also have a trilobed-shape formed by three circles having outside diameters of 0.556 inches with a spacing of 0.549 inches on center, and a length of about 0.375 inches. End plugs 308 are positioned within interior space 306a flush with the ends of tube 306, such that the length of interior space 306a between the end plugs is only about 34.25 inches.
In a preferred embodiment, the compression rods are made of hardened steel, the casings or tubes are made of aluminum, and the end plugs are made of steel.
Compression bars 100, 150 and 300 are particularly suited for retrofit installation in the interior space of a standard hollow door. One or more compression bars may be inserted laterally within the door to span across the width of the door. The compression bars may be the same type, or may be a combination of different types.
The compression bars may be oriented and secured in position within the interior space of door 400 by brackets.
Compression bar brackets 404 and 406 may be made of metal or other materials as are known in the art. In a preferred embodiment, compression bar brackets 404 and 406 are made of steel. Once compression bars 300, 100 and 150 are installed within door 400, the interior of the door may be filled with a fire retardant material, such as a fire retardant foam. Conventional metal doors commonly have cores that contain honeycombed-shaped cardboard, which can catch fire from the frictional heat produced by cutting tools. The use of fire retardant materials reduces the risk of fire. In addition, fire retardant foams can bond the security assembly to the outer skin or shell of the door.
In one embodiment, one or more anti-drill plates 410 may be attached to door 400 to improve resistance to drilling.
In one embodiment, hinge bracket 508 is formed as a metal slat that has a Z-shape cross-section and a length that is sufficient to extend beyond the top and bottom hinges of door 500. In a preferred embodiment, hinge bracket 508 is made of steel and has a length of about 68.75 inches. Hinge bracket 508 may be secured to the rear side of door 502 through one or more anti-drill plates 410.
As best shown in
A drill 812 is shown with a drill bit 812a. As drill bit 812a drills through door 802 and comes into contact with a plate 806, hinge 808 allows the plate to rotate away such that the drill bit cannot drill a hole through the plate. Once drill bit 812a is withdrawn, plate 806 is urged back toward door 802 by spring 810 to cover the hole in the door and prevent the insertion of a tool through the hole to access push bar 804.
End plugs 908 and 909 are sized and shaped to fit within interior space 906a and are positioned at the opposite ends of tube 906, adjacent to springs 904 and 905. Corresponding openings may be formed at the ends of the casing and in the end plugs, for receiving end plug pins to secure the end plugs in position and retain the inner and outer compression rod assemblies under compression—for example, corresponding openings 906b and 908a, and end plug pin 910 for securing end plug 908. In one embodiment, end plug 909 has a threaded hole 909a for receiving a set screw 912 to adjust the compression of the inner compression rod assembly. An extension pin 914 may be inserted through the center of spring 905 to couple set screw 912 to inner rod 902.
In one embodiment, inner rod 902 has a similar configuration as rod 102, with a hexagonal cross-section. Outer rod 903 may be a hollow cylinder, with an interior space 903a having a circular cross-section that is sized to receive rod 902, such that there is only point contact between the two rods. Casing 906 may also be a hollow cylinder with an interior space 903a having a circular cross-section that is sized to receive rod 903. In an alternative embodiment, outer rod 903 may have an outer circumference that is hexagonal or other shape such that there is only point contact between the outer rod and casing 906.
The telescoping design of compression bar 900 has a number of advantages. It provides a design with two compression rods that is generally more compact and less complex to manufacture than lobed compression bar 200. It allows for a larger, thicker spring 905 for outer rod 903, which increases the compressive force. In addition, springs 904 and 905 exert compressive forces in opposite directions, which is believed to improve the ability of the compression bar to arrest a cutting blade.
Trilobed end plugs 1008 and 1009 are sized and shaped to fit within interior space 1007 and are positioned at the opposite ends of casing 1006, adjacent to spring 1004 at one end and rods 1002 at the other end. Corresponding openings are formed at the ends of casing 1006 (openings 1006a) and in end plugs 1008 and 1009 (not shown) for receiving pins 1010 to secure the end plugs in position and retain the compression rod assembly under compression. End plugs 1008 and 1009 may have either a trilobe shape similar to end plugs 308 (e.g., end plug 1008) or the compound shape of interior space 1007 (end plug 1009). Compression plate 1012 is similarly shaped to fit within interior space 1007, and may have either a trilobe shape or compound shape.
The single spring, trilobe design of compression bar 1000 allows spring 1004 to have a much larger outside diameter and wire diameter in comparison to springs 304 of compression bar 300. For example, spring 1004 may have an outside diameter of about 1 inch. This permits spring 1004 to exert greater compressive force on rods 1002, and increases the ability of compression bar 1000 to stop a cutting blade and self-heal. Similarly to end plugs 308, end plugs 1008 and/or 1009 may have threaded holes (e.g., 1009a) for receiving set screws (not shown) to adjust the compression of the compression rod assembly.
In some cases, forced entry is attempted by inserting a pry tool between the door and the frame. Hollow doors and frames may be susceptible to being bent or crushed to create sufficient space to force the end of the pry tool behind the end of the door and pry the door from the frame. Reinforcing plates (e.g., plates 410), may be attached to the door to increase resistance to bending or crushing. However, it would be desirable to protect the door from insertion of a pry tool between the door and frame. For example, an astragal may be used to protect against insertion of a pry tool between the lock side of the door and frame, as described above. However, a similar device does not exist for protecting the hinge side of the door.
An alternative embodiment of a hinge bracket is shown in
Door 1102 is hingedly mounted on frame 1104 by a hinge bracket 1108 having a length that preferably extends substantially the height of the door. Hinge bracket 1108 comprises a frame leaf 1108a and a door leaf 1108b that are rotatably coupled by a pin 1108c. Frame leaf 1108a is positioned on the outer surface 1104a of frame 1104, and is preferably sized and shaped to conform to and sit flush against the outer surface of the frame. Frame leaf 1108a (and hinge bracket 1108) may be secured to frame 1104 by bolts, screws, rivets, or other fasteners known in the art. In a preferred embodiment, frame leaf 1104a is secured to frame 1104 by a through bolt 1110 that extends through frame 1104 on either side 1104a and 1104b, as best shown in
Door leaf 1108b is positioned on end 1102c of door 1102, within the space 1112 between the end of the door and frame 1104. Door leaf 1108b is preferably sized and shaped to conform to and sit flush against the outer surface of end 1102c of door 1102. In one embodiment, door leaf 1108b has a width that is greater than the width of end 1102c of door 1102, such that the end 1108d of the door leaf extends beyond end 1102c toward the inner surface 1102b of the door. In a preferred embodiment, door leaf 1108b is bent to conform to the corner 1102d between end 1102c and inner surface 1102b of door 1102, such that the door leaf (including end 1108d) sits flush against the end and inner surface of the door. Door leaf 1104b (and hinge bracket 1108) may be secured to end 1102c of door 1102 by bolts, screws, rivets, or other means known in the art that may be adapted to fit within the space between the end of the door and frame 1104.
In operation, hinge bracket 1108 extends across and covers the space 1112 between door 1102 and frame 1104, to protect against insertion of a pry tool between the hinge side of the door and frame. Door leaf 1108b is secured to and positioned flush against end 1102c of door 1102, to increase the difficulty in inserting a pry tool between hinge bracket 1008 and the door. Door leaf 1108b is bent to wrap around end 1102c of door 1102, and door leaf end 1108d is positioned flush against inner surface 1102b of the door, which further increases the difficulty of inserting a pry tool behind the end of the door to pry the door from the frame.
Openings 1122 may be formed in the side of door 1102 for the insertion of compression bars 300, 150 and 100 within the hollow door, similarly to system 700. In one embodiment, compression bars 300, 150 and 100 may be supported within door 1102 by the fire retardant foam, without the need for compression bar brackets 404 and 406. Once compression bars 300, 150 and 100 are installed within door 1102, the openings 1122 may be covered by cover plates 1124, similarly to cover plates 408a and 408b described above. Alternatively, openings 1122 may be formed on end 1102c of door 1102, such that openings 1122 are covered when hinge bracket door leaf 1108b is secured to the end of the door.
In one embodiment, one or more anti-drill plates 1118a and/or 1118b may be attached to door 1102 to improve resistance to drilling, similarly to plates 410 described above. Plates 1118a and 1118b may be made of different materials with different properties (e.g., hardness and toughness). For example, plates 1118a positioned at the top and bottom of the door, which are at lower risk of attack, may be made of materials with greater impact strength (e.g., aluminum alloys). Plates 1118b positioned near the lock may be made of drill-resistant materials (e.g., hardened steel). The impact strength of drill-resistant plates 1118b may be improved by positioning one or more additional plates 1120 over plates 1118b. For example, plates 1118b may be sandwiched between plates 1120 and door 1102. In a preferred embodiment, plates 1120 and 1118a are made of the same impact resistant material.
Referring to
A compression bar 1214 is coupled to one or more slats 1206 to improve the cut resistance of security door system 1200. Multiple compression bars 1214 may be distributed across the slats of rolling door 1202, or may be limited to those slats that are at highest risk of attack. For example, compression bars 1214 may be positioned on alternating slats that comprise the lower half of rolling door 1202, as best shown in
Compression bars 1214 may be coupled to inner side 1208b of slat body 1208, and are preferably configured to conform to the inner side of the slat. In the embodiment of
In a preferred embodiment, slat 1206 and compression bar 1214 are configured such that the compression bar does not interfere with the process of retracting rolling door 1202—e.g., by increasing the diameter of the wound rolling door 1202 in the retracted position. In the embodiment of
It will be apparent to those of skill in the art that changes and modifications may be made in the embodiments illustrated herein, without departing from the spirit and scope of the invention.
This application claims the benefit of U.S. Provisional Application No. 63/077,421, filed on Sep. 11, 2020, which is hereby incorporated by reference in its entirety.
Number | Name | Date | Kind |
---|---|---|---|
91342 | Ireland | Jun 1869 | A |
6047999 | Dixon, Jr. | Apr 2000 | A |
8550506 | Nakanishi | Oct 2013 | B2 |
20040189012 | Katou | Sep 2004 | A1 |
20100013244 | Shimizu | Jan 2010 | A1 |
20210324667 | Grillo | Oct 2021 | A1 |
20220112748 | Guillemette | Apr 2022 | A1 |
Number | Date | Country |
---|---|---|
1669536 | Jun 2006 | EP |
3023572 | Jan 2016 | FR |
2404215 | Apr 2007 | GB |
380890 | Aug 1991 | JP |
5305064 | Sep 2009 | JP |
2004104354 | Dec 2004 | WO |
Entry |
---|
PROFILMAR Catalog (2018). |
Number | Date | Country | |
---|---|---|---|
63077421 | Sep 2020 | US |