EP0108553A2 - Security bars - Google Patents
Security bars Download PDFInfo
- Publication number
- EP0108553A2 EP0108553A2 EP83306499A EP83306499A EP0108553A2 EP 0108553 A2 EP0108553 A2 EP 0108553A2 EP 83306499 A EP83306499 A EP 83306499A EP 83306499 A EP83306499 A EP 83306499A EP 0108553 A2 EP0108553 A2 EP 0108553A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- bar
- skin
- core
- bar according
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E06—DOORS, WINDOWS, SHUTTERS, OR ROLLER BLINDS IN GENERAL; LADDERS
- E06B—FIXED OR MOVABLE CLOSURES FOR OPENINGS IN BUILDINGS, VEHICLES, FENCES OR LIKE ENCLOSURES IN GENERAL, e.g. DOORS, WINDOWS, BLINDS, GATES
- E06B9/00—Screening or protective devices for wall or similar openings, with or without operating or securing mechanisms; Closures of similar construction
- E06B9/01—Grilles fixed to walls, doors, or windows; Grilles moving with doors or windows; Walls formed as grilles, e.g. claustra
Definitions
- the present invention relates to security bars which may be made up into grilles or gratings eg to cover the window openings in security buildings for protection against intrusion or escape, for use as glazing bars or mullions in security applications, or for use more generally in the field of security grilles and shutters.
- An aim of the invention is to provide a security bar having high resistance to both bending and cutting and, in particular, superior resistance to attack with metal-cutting saws or files than is the case with traditional steel window bars.
- the invention proposes a composite form of bar comprising a core of a steel or other material having high resistance to bending surrounded by a layer which comprises elements of very hard material bound in a cast matrix.
- the bending-resistant core is disposed within and spaced from an outer finishing skin and the matrix which binds the very hard elements is cast in situ within the space defined between the core and skin.
- Figure I shows part of a masonry wall 1 having a window opening 2, and let in to this opening is a grating comprising a plurality of parallel bars 3 held in a steel frame 4.
- the bars 3 are designed to offer high resistance to intrusion or escape through the grating either by bending the bars apart or by cutting them through eg with carbide-coated rod- or hack-saws or files, and each one is of the general form indicated in Figure 2.
- the bar 3 is seen to be of composite construction comprising a central core 5, an outer finishing skin 6 and a hard layer 7 filling the space between the core and skin.
- the core 5 provides most of the bar's resistance to bending and is preferably made from steel of a type which can be given a high elastic limit, it being resistance to plastic (ie permanent) deformation which is of importance in the context of a bar provided for the above- mentioned purpose.
- the steel may be given a hard surface layer and the characteristics of the surface hardening method may influence the choice of steel.
- the possibilities include a low carbon, substantially unalloyed, steel bar in which a high yield strength has been induced by "cold working"; carbon steels which can be given a high surface hardness by an induction or flame hardening method; and low alloy steels which can be through-hardened to provide a high yield strength and this treatment combined, if necessary, with a hardened surface, (the latter may be suitable for surface hardening by carburising or nitriding treatments followed by a heat treatment to impart high strength to the steel interior).
- the filling 7, which provides most of the resistance to cutting, is itself a composite material, comprising elements 8 of a very hard material (preferably in excess of 1000kg/mm 2 , or 7 on the Moh scale) bound in a cast matrix 9.
- the hard material 8 will typically be an oxide, silicate or carbide whether synthetic or natural. More particularly, alumina or silicon carbide particles are presently preferred. These particles should be in the form of dense nuggets of high quality, such as may be made by fusion or sintering processes.
- the matrix material 9 contains, supports and bonds the hard elements 8 in a homogeneous mass, and is preferably formed from a rigidly-setting polymer or an inorganic hydraulic cementitious material.
- the nuggets 8 will be placed into the space defined between the core 5 and skin 6, suitably mounted in jigs, and then the liquid resin together with a catalytic hardener (or the wet cement paste) will be cast in to fill the interstices between the nuggets, core and skin.
- the nuggets and matrix material might be p r e-mixed and cast together into the space between the core and skin.
- a cold setting matrix material is preferred in order to avoid any thermal distortion or discolouration of the relatively thin skin 6.
- the hard elements 8 it is possible for the hard elements 8 to be cast with a molten metal matrix material, eg aluminium, if desired.
- the material of the outer skin 6 should be corrosion resistant and readily formable to the required section, and in the finished bar should have a smooth external surface to aid the detection of damage.
- the preferred material in this respect is a stainless steel or aluminium alloy.
- bars in accordance with the invention may be made in a simple circular form with the outer skin concentric with the core
- the elongate cross-sectional form indicated in Figure 2 is considered to represent a more optimum solution to the conflicting requirements of maximum security and reasonable daylight transmission between the spaced bars.
- the orientation of the bars in the grating is such that from the viewpoint of Figure 2 the upper part of the figure represents the inside of the building and the lower part represents the outside.
- the elongate form of bar increases the area of material which has to be cut through in comparison with a circular bar of the same width (that is the cross-sectional dimension of the bar in the plane of the grating).
- the outer skin 6 may in itself contribute little to the structural strength or resistive properties of a bar 3 it is of value in shielding the layer 7 from attack by other (non-cutting) forms of tool to which that layer may be more vulnerable, and it is important therefore that the skin 6 should not be readily detachable from the rest of the bar.
- Figures 3a and 3b show variations of the Figure 2 cross section in accordance with this concept, where portions 10 of the skin are profiled to project into the hard filling space.
- Figure 3c shows an example with outward projections 11 for the same purpose, and of course combinations of inward and outward projections may also be adopted.
- FIG. 4a shows an example with L-shaped rod anchors 12 welded to the skin at intervals along the length of the bar;
- Figure 4b shows alternative hoop anchors 13 welded across internal corners of the skin;
- Figure 4a shows anchors 14 integral with the skin along the whole length of the bar, where the skin and anchors are formed together in an extruded section.
- Figure 5 shows a further variant of the bar where the steel core 5' in this case is tubular and contains a second hard filling 15.
- This filling may be similar to the composite filling 7, perhaps containing even harder elements such as sintered tungsten carbide.
- the space within a tubular core may contain rotatable bodies such as rods or balls of hardened steel or ceramics, to frustrate attempts to saw or file through the core.
- a wire or other form of detector may be contained within the structure of the bar, and the use of a cold castable filling 7 makes it easy to incorporate a detector within the space between the core 5 and skin 6 at the time of manufacture.
- Figure 6 indicates a simple example with a single detector wire 16 provided in the filling 7, so that an alarm is triggered if the wire is severed by an attempt to cut the bar.
- Wires embedded in the rigid cast matrix can also be arranged to fracture if the bar is deformed and will therefore detect bending as well as cutting.
- More complex detection systems may be employed with the'detector elements provided within a tubular core such as 5' instead of, or as well as, within the filling 7.
Landscapes
- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
- Laminated Bodies (AREA)
- Building Environments (AREA)
Abstract
Description
- The present invention relates to security bars which may be made up into grilles or gratings eg to cover the window openings in security buildings for protection against intrusion or escape, for use as glazing bars or mullions in security applications, or for use more generally in the field of security grilles and shutters.
- An aim of the invention is to provide a security bar having high resistance to both bending and cutting and, in particular, superior resistance to attack with metal-cutting saws or files than is the case with traditional steel window bars. Accordingly in one broad aspect the invention proposes a composite form of bar comprising a core of a steel or other material having high resistance to bending surrounded by a layer which comprises elements of very hard material bound in a cast matrix. Most preferably the bending-resistant core is disposed within and spaced from an outer finishing skin and the matrix which binds the very hard elements is cast in situ within the space defined between the core and skin.
- These and other features of the present invention will become apparent from the ensuing description of preferred examples thereof taken in conjunction with the accompanying schematic drawings, in which:
- Figure 1 illustrates a window grating comprising bars in accordance with the invention;
- Figure 2 is a horizontal cross-section through an individual bar of the grating;
- Figures 3a to 3c and 4a to 4c are half sections through variants of the bar of Figure 2; and
- Figures 5 and 6 are cross-sections through further variants of the bar.
- Referring to the drawings, Figure I shows part of a masonry wall 1 having a window opening 2, and let in to this opening is a grating comprising a plurality of
parallel bars 3 held in a steel frame 4. Thebars 3 are designed to offer high resistance to intrusion or escape through the grating either by bending the bars apart or by cutting them through eg with carbide-coated rod- or hack-saws or files, and each one is of the general form indicated in Figure 2. - With reference to Figure 2, the
bar 3 is seen to be of composite construction comprising acentral core 5, anouter finishing skin 6 and ahard layer 7 filling the space between the core and skin. Thecore 5 provides most of the bar's resistance to bending and is preferably made from steel of a type which can be given a high elastic limit, it being resistance to plastic (ie permanent) deformation which is of importance in the context of a bar provided for the above- mentioned purpose. In some embodiments the steel may be given a hard surface layer and the characteristics of the surface hardening method may influence the choice of steel. The possibilities include a low carbon, substantially unalloyed, steel bar in which a high yield strength has been induced by "cold working"; carbon steels which can be given a high surface hardness by an induction or flame hardening method; and low alloy steels which can be through-hardened to provide a high yield strength and this treatment combined, if necessary, with a hardened surface, (the latter may be suitable for surface hardening by carburising or nitriding treatments followed by a heat treatment to impart high strength to the steel interior). - The
filling 7, which provides most of the resistance to cutting, is itself a composite material, comprising elements 8 of a very hard material (preferably in excess of 1000kg/mm2, or 7 on the Moh scale) bound in acast matrix 9. The hard material 8 will typically be an oxide, silicate or carbide whether synthetic or natural. More particularly, alumina or silicon carbide particles are presently preferred. These particles should be in the form of dense nuggets of high quality, such as may be made by fusion or sintering processes. Thematrix material 9 contains, supports and bonds the hard elements 8 in a homogeneous mass, and is preferably formed from a rigidly-setting polymer or an inorganic hydraulic cementitious material. It is envisaged that in manufacturing thebar 3 the nuggets 8 will be placed into the space defined between thecore 5 andskin 6, suitably mounted in jigs, and then the liquid resin together with a catalytic hardener (or the wet cement paste) will be cast in to fill the interstices between the nuggets, core and skin. Alternatively the nuggets and matrix material might be pre-mixed and cast together into the space between the core and skin. A cold setting matrix material is preferred in order to avoid any thermal distortion or discolouration of the relativelythin skin 6. However, in other embodiments it is possible for the hard elements 8 to be cast with a molten metal matrix material, eg aluminium, if desired. - The material of the
outer skin 6 should be corrosion resistant and readily formable to the required section, and in the finished bar should have a smooth external surface to aid the detection of damage. The preferred material in this respect is a stainless steel or aluminium alloy. - Although bars in accordance with the invention may be made in a simple circular form with the outer skin concentric with the core, the elongate cross-sectional form indicated in Figure 2 is considered to represent a more optimum solution to the conflicting requirements of maximum security and reasonable daylight transmission between the spaced bars. The orientation of the bars in the grating is such that from the viewpoint of Figure 2 the upper part of the figure represents the inside of the building and the lower part represents the outside. The elongate form of bar increases the area of material which has to be cut through in comparison with a circular bar of the same width (that is the cross-sectional dimension of the bar in the plane of the grating). Also, if a hand saw or file is used in an attempt to cut a bar, space considerations dictate that in general it will have to be worked perpendicularly to the plane of the grating, that is in the fore-and-aft direction in relation to the elongate bar, which represents the longer line of required cut to the tool. Tapering the noses of the bars at the inside face of the grating, as indicated in Figure 2, further aids daylight transmission.
- Although the
outer skin 6 may in itself contribute little to the structural strength or resistive properties of abar 3 it is of value in shielding thelayer 7 from attack by other (non-cutting) forms of tool to which that layer may be more vulnerable, and it is important therefore that theskin 6 should not be readily detachable from the rest of the bar. In order to strip away a portion of the skin several cuts through it would be necessary and one way in which such removal can be made very much more difficult is to configure the skin such that any anticipated line of cut with a saw or file which would achieve removal of a sizeable portion of the skin must also pass through a portion of thehard filling 7. Figures 3a and 3b show variations of the Figure 2 cross section in accordance with this concept, whereportions 10 of the skin are profiled to project into the hard filling space. Figure 3c shows an example withoutward projections 11 for the same purpose, and of course combinations of inward and outward projections may also be adopted. - Another measure aimed at resisting separation of the
skin 6 from thefilling 7, and which may be used as an addition or an alternative to profiling the skin as indicated above, is to provide the skin with anchor members extending into the : mass of the cast filling 7. Figure 4a shows an example with L-shaped rod anchors 12 welded to the skin at intervals along the length of the bar; Figure 4b showsalternative hoop anchors 13 welded across internal corners of the skin; and Figure 4a showsanchors 14 integral with the skin along the whole length of the bar, where the skin and anchors are formed together in an extruded section. - Figure 5 shows a further variant of the bar where the steel core 5' in this case is tubular and contains a second
hard filling 15. This filling may be similar to thecomposite filling 7, perhaps containing even harder elements such as sintered tungsten carbide. In another variation the space within a tubular core may contain rotatable bodies such as rods or balls of hardened steel or ceramics, to frustrate attempts to saw or file through the core. - In certain circumstances it will be desirable to detect remotely any attempts to compromise a
bar 3. For this purpose a wire or other form of detector may be contained within the structure of the bar, and the use of a coldcastable filling 7 makes it easy to incorporate a detector within the space between thecore 5 andskin 6 at the time of manufacture. Figure 6 indicates a simple example with asingle detector wire 16 provided in thefilling 7, so that an alarm is triggered if the wire is severed by an attempt to cut the bar. Wires embedded in the rigid cast matrix can also be arranged to fracture if the bar is deformed and will therefore detect bending as well as cutting. More complex detection systems may be employed with the'detector elements provided within a tubular core such as 5' instead of, or as well as, within thefilling 7.
Claims (14)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB8231628 | 1982-11-05 | ||
GB8231628 | 1982-11-05 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0108553A2 true EP0108553A2 (en) | 1984-05-16 |
EP0108553A3 EP0108553A3 (en) | 1984-09-05 |
Family
ID=10534050
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP83306499A Withdrawn EP0108553A3 (en) | 1982-11-05 | 1983-10-26 | Security bars |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP0108553A3 (en) |
AU (1) | AU2091383A (en) |
GB (1) | GB2129859B (en) |
HK (1) | HK73487A (en) |
IE (1) | IE54660B1 (en) |
MY (1) | MY8700657A (en) |
SG (1) | SG28987G (en) |
ZA (1) | ZA838121B (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3700449A1 (en) * | 1987-01-09 | 1988-07-28 | Johannes Heyen | Process for the protection of high-voltage pylons against sabotage |
DE9210896U1 (en) * | 1992-08-14 | 1992-10-29 | Sälzer Sicherheitstechnik GmbH, 3550 Marburg | Lattice bar |
WO1994010419A1 (en) * | 1992-10-31 | 1994-05-11 | Bau-Und Maschinenschlosserei Herwart Lohr | Device for fastening a grating frame |
DE19625656A1 (en) * | 1996-06-26 | 1998-01-02 | Sommer Metallbau Stahlbau Gmbh | Object security grille |
EP0973982A1 (en) * | 1997-03-07 | 2000-01-26 | Supersafe Ltd. | Structural protective system and method |
EP1561895A2 (en) * | 2004-02-06 | 2005-08-10 | Castagna, Annunzio | Anticutting bar |
JP2020186524A (en) * | 2019-05-10 | 2020-11-19 | 株式会社アルファ | Bar lock device |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100387896C (en) * | 2005-11-18 | 2008-05-14 | 李峰 | Composite stainless steel rod with rainforced structure and its mfg. method |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1504677A (en) * | 1923-05-09 | 1924-08-12 | Charles R Carter | Metal bar |
US3552938A (en) * | 1969-01-21 | 1971-01-05 | C M Windows & Stained Glass Lt | Security steel members with carbide inserts |
DE7112516U (en) * | 1971-10-14 | Kreuzlingen W | Security grille | |
DE2653056B2 (en) * | 1976-11-23 | 1980-09-11 | Bochumer Eisenhuette Heintzmann Gmbh & Co, 4630 Bochum | Protection device for the air passage areas of rooms or buildings |
DE2925624A1 (en) * | 1979-06-26 | 1981-01-15 | Geiger Maschf Helmut | Safety bar screen for power stations - produces warning signal of any interference attempt by frogmen |
DE7922696U1 (en) * | 1979-08-08 | 1981-05-21 | Fipke, Boris | DEVICE FOR SECURING PARTICULAR LIGHTS OR THE LIKE AGAINST BURGLAR |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1567717A (en) * | 1977-12-30 | 1980-05-21 | Pentagon Ind Ltd | Security window unit |
-
1983
- 1983-10-26 GB GB08328652A patent/GB2129859B/en not_active Expired
- 1983-10-26 EP EP83306499A patent/EP0108553A3/en not_active Withdrawn
- 1983-10-27 IE IE2522/83A patent/IE54660B1/en unknown
- 1983-10-31 ZA ZA838121A patent/ZA838121B/en unknown
- 1983-11-02 AU AU20913/83A patent/AU2091383A/en not_active Abandoned
-
1987
- 1987-03-24 SG SG289/87A patent/SG28987G/en unknown
- 1987-10-07 HK HK734/87A patent/HK73487A/en unknown
- 1987-12-30 MY MY657/87A patent/MY8700657A/en unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE7112516U (en) * | 1971-10-14 | Kreuzlingen W | Security grille | |
US1504677A (en) * | 1923-05-09 | 1924-08-12 | Charles R Carter | Metal bar |
US3552938A (en) * | 1969-01-21 | 1971-01-05 | C M Windows & Stained Glass Lt | Security steel members with carbide inserts |
DE2653056B2 (en) * | 1976-11-23 | 1980-09-11 | Bochumer Eisenhuette Heintzmann Gmbh & Co, 4630 Bochum | Protection device for the air passage areas of rooms or buildings |
DE2925624A1 (en) * | 1979-06-26 | 1981-01-15 | Geiger Maschf Helmut | Safety bar screen for power stations - produces warning signal of any interference attempt by frogmen |
DE7922696U1 (en) * | 1979-08-08 | 1981-05-21 | Fipke, Boris | DEVICE FOR SECURING PARTICULAR LIGHTS OR THE LIKE AGAINST BURGLAR |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3700449A1 (en) * | 1987-01-09 | 1988-07-28 | Johannes Heyen | Process for the protection of high-voltage pylons against sabotage |
DE9210896U1 (en) * | 1992-08-14 | 1992-10-29 | Sälzer Sicherheitstechnik GmbH, 3550 Marburg | Lattice bar |
WO1994010419A1 (en) * | 1992-10-31 | 1994-05-11 | Bau-Und Maschinenschlosserei Herwart Lohr | Device for fastening a grating frame |
EP0965800A3 (en) * | 1996-06-26 | 2000-06-28 | Sommer Metallbau-Stahlbau GmbH & Co. KG | Safety-grill |
EP0965800A2 (en) * | 1996-06-26 | 1999-12-22 | Sommer Metallbau-Stahlbau GmbH & Co. KG | Safety-grill |
DE19625656A1 (en) * | 1996-06-26 | 1998-01-02 | Sommer Metallbau Stahlbau Gmbh | Object security grille |
DE19625656C2 (en) * | 1996-06-26 | 2001-02-22 | Sommer Metallbau Stahlbau Gmbh | Object security grille |
EP0973982A1 (en) * | 1997-03-07 | 2000-01-26 | Supersafe Ltd. | Structural protective system and method |
EP0973982A4 (en) * | 1997-03-07 | 2002-10-16 | Supersafe Ltd | Structural protective system and method |
EP1561895A2 (en) * | 2004-02-06 | 2005-08-10 | Castagna, Annunzio | Anticutting bar |
EP1561895A3 (en) * | 2004-02-06 | 2006-06-21 | Annunzio Castagna | Anticutting bar |
JP2020186524A (en) * | 2019-05-10 | 2020-11-19 | 株式会社アルファ | Bar lock device |
JP7263108B2 (en) | 2019-05-10 | 2023-04-24 | 株式会社アルファ | bar lock device |
Also Published As
Publication number | Publication date |
---|---|
MY8700657A (en) | 1987-12-31 |
HK73487A (en) | 1987-10-16 |
AU2091383A (en) | 1984-05-10 |
GB2129859B (en) | 1986-09-17 |
EP0108553A3 (en) | 1984-09-05 |
GB2129859A (en) | 1984-05-23 |
IE54660B1 (en) | 1989-12-20 |
SG28987G (en) | 1987-07-10 |
GB8328652D0 (en) | 1983-11-30 |
IE832522L (en) | 1984-05-05 |
ZA838121B (en) | 1984-06-27 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Designated state(s): AT BE CH DE FR IT LI LU NL SE |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Designated state(s): AT BE CH DE FR IT LI LU NL SE |
|
17P | Request for examination filed |
Effective date: 19850302 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 19860430 |
|
RIN1 | Information on inventor provided before grant (corrected) |
Inventor name: SANDS, RAYMOND LEONARD Inventor name: WILLIS, DAVID CHRISTOPHER |