Title of Invention: Heated Safety Glazing

Technical Field

[0001] The present invention discloses heated safety glazing units equipped with protection against overheating and security system.

Background Art

[0002] Various methods for the heating of glazing units have been employed for a long time in particular in vehicles. For example, the CZ 286724 B6 publication discloses an assembly of a pair of glass plate-like parts separated by a layer of polyvinyl butyral with an embedded heating circuit.

[0003] In addition, glass preventing condensation is disclosed, for example, in the EP

1626940 document. The glass is coated with a layer heated by electric current. The aforementioned glass is intended for freezers and its purpose is to make products clearly visible.

[0004] However, the design of heated windows known so far is not sufficiently resolved in terms of protection against overheating or protection against breaking and entering.

[0005] This is a serious disadvantage considering the fact that windows are the weakest link of a building security against breaking and entering. 85% of perpetrators enter buildings via windows and 80% of perpetrators are not afraid of being exposed by in habitants in neighbouring buildings, however, they have difficulties in overcoming burglary monitoring systems, i.e. connection of buildings to security alarm receiving centres.

[0006] Nowadays, the safeguarding of windows against breaking and entering is performed by mechanical protection based on safety films. The window equipped with such film is not completely transparent and the mechanical protection created in this manner is not sufficient to withstand brute force. The situation may be partially improved by a shock sensor additionally stuck on the window. Such a solution does not look good and requires additional installation. Moreover, the glued-on sensor may not remain attached to the window.

[0007] In known heated windows, fire safety in the case of heated glass cracking, when electric arc occurs in the point of connection of the power supply conductor, has not been resolved satisfactorily yet. From the EP 1017254 A1 document, a heated window fitted with a heated layer connected via peripheral electrodes to a power supply unit with temperature control both by the sensor on the window and by a spatial thermostat is known. If the heated glass breaks, cracks spread over the entire surface, but the glass still may not disintegrate. However, electric arc can develop on the crack with a sig- nificantly high temperature potentially lasting for a very long time. In such a case, the window frames get considerably damaged and could even catch fire.

[0008] With metal window frames, glass is separated from the frame by window seal, which means that if electric arc develops, electric circuit protection is not activated while in sulation material is partly melted and can even catch on fire. In the case of a plastic window frame, the frame can be melted down or even ignite. With a wooden frame, ignition is the most likely as the temperature of electric arc exceeds the ignition tem perature of wood many times.

Summary of Invention

[0009] The heated safety glazing is comprised of at least two flat glass substrates, of which at least one is hardened and equipped on its inner side with an electrically conductive heating mesh. Flat glass substrates that are separated by a chamber filled with some inert gas with low thermal conductivity are embedded in a common frame. All flat glass substrates are formed by monolithic soda-lime glass with a thickness of 3 to 8 mm comprising 70 to 72.5% by weight of Si02, 13 to 14% by weight of Na20, 9 to 10% by weight of CaO, 4 to 5% by weight of MgO, 0.60 to 0.75% by weight of A1203, 0.10 to 0.14% by weight of K20, 0.25 to 0.27% by weight of S03, and up to 1% by weight of other added substances. The electrically conductive heating mesh is made of Sn02:F with the thickness of 5 to 100 nm, with the transmissivity in the visible region of 79 to 84%, opacity for ultraviolet radiation of 84 to 86%, and re flectivity of infra-red radiation of 57 to 59%. It is designed in the form of mutually connected convex polygons allowing surface current density in the entire electrically conductive heating mesh to be constant and supplied by the first and second heating electrode. The first heating electrode is connected by a conductor via a relay switch to a phase conductor of a controllable thermostat connected to electric power supply. The second heating electrode is connected by a conductor to the neutral connector of the electric power supply that is connected via the relay winding and a conductor to the phase conductor via a safety electrode; the phase conductor that is led in the chamber inside the frame is connected via a magnetic contact to the electricity supply network by a conductor to the phase conductor of the controllable thermostat to which also a temperature sensor is connected by a conductor; the temperature sensor is positioned at the edge of the glass substrate and the relay contact is connected to the digital input of the control system via the control unit in the electrical control panel transmitting random impulses to verify the closed position of the heating circuit.

[0010] The neighbouring glass substrates have mutual distance of 9 to 30 mm depending on the width of the chamber filled with some inert gas with low thermal conductivity delimited by a plastic spacer frame with a rectangular cross-section with bevelled comers at the base. The base as well as the adjacent bevelled corners are fitted with a moisture- stop aluminium coat reaching up to a half of its length adjacent to the base. The plastic spacer frame is filled with a synthetic crystalline aluminosilicate -based molecular sieve with a three-dimensional system of pores with the diameter ranging from 0.29 to 0.31 nm, permanently attached along the vertical sides by flexible non conducting polyisobutylene-based binding material and along the base and the bevelled comers by two-part polysulphide-based fixing sealant. The inert gas is selected from a group comprising argon and krypton.

[0011] In a preferred embodiment, the conductors are led together via a disconnectable connector. The convex polygons forming the electrically conductive heating mesh are preferably selected from a group comprising triangles, quadrangles, and hexagons. In a preferred embodiment the number of flat glass substrates is three and the substrate in the middle is preferably on its interior side fitted with a reflective layer.

[0012] In a preferred embodiment, the exterior glass substrate is fitted on its inner side with the electrically conductive heating mesh. In another embodiment, the external exterior glass substrate is equipped on its inner side with a reflective layer.

[0013] In a preferred embodiment, the convex polygons of the electrically conductive

heating mesh have the width of the side (m) and the width of the side (n) ranging from 2.4 to 6.5 mm and the length of the side (k) and the length of the side (1) ranging from 11.41 to 51 mm.

[0014] The heated safety glazing according to the invention prevents water vapour con densation on the window and thus formation of mildew. It has been ascertained that in winter season the temperature of the safety glazing prevents frost deposits formation.

In a majority of applications, it is sufficient for space heating.

[0015] If the heating glass breaks, cracks will spread over the entire glass and the circuit is interrupted on the safety electrode. No electric arc is formed as the current flowing through the electrode amounts to only a few mA. By interrupting the circuit on the safety electrode, the relay is disengaged and the contact, via which the first heating electrode is supplied with electric power, is disconnected and the heating glazing is disconnected from the electric power supply.

Brief Description of Drawings

Fig·!

[0016] [Fig.l] illustrates the section of the heating safety glass in various variants,

Fig.2

[0017] [Fig.2] illustrates the section of the heating safety glass in various variants,

Fig.3

[0018] [Fig.3] illustrates the section of the heating safety glass in various variants, Fig.4

[0019] [Fig.4] illustrates the connection of the heating mesh in various variants,

Fig.5

[0020] [Fig.5] illustrates the connection of the heating mesh in various variants,

Fig.6

[0021] [Fig.6] illustrates various embodiments of the heating mesh,

Fig.7

[0022] [Fig.7] illustrates various embodiments of the heating mesh,

Fig.8

[0023] [Fig.8] illustrates various embodiments of the heating mesh,

Fig.9

[0024] [Fig.9] illustrates various embodiments of the heating mesh.

Examples

[0025] Example 1

[0026] An example of embodiments of the heating safety window is provided in Fig. 1, Fig.

4, and Fig. 6.

[0027] A heating safety window with an openable wooden frame D with the size of h = 1,100 mm and s = 800 mm, connected with a fixed wooden frame D on the side h using three hinge plates was manufactured. The frame D was fitted with two flat glass substrates 1, 7 with the size of h = 1,000 mm and s = 700 mm manufactured from monolithic soda-lime glass with the thickness of 3 mm, comprising 72.5% by weight of Si02, 13% by weight of Na20, 9.0% by weight of CaO, 4% by weight of MgO, 0.60% by weight of A1203, 0.10% by weight of K20, 0.25% by weight of S03, and 0.55% by weight of other added substances. The glasses were separated by the chamber 9 filled with argon. The flat glass substrate 7 was fitted with a reflective layer 12 with the emissivity of 0.03. The flat glass substrate 1 was hardened and on its inner side fitted with an electrically conductive heating mesh 6 with the thickness of 5 nm, made of Sn02:F, the transmissivity of which in the visible region was 84%, ultraviolet radiation opacity was 84%, and the infra-red radiation reflectivity was 57%. The elec trically conductive heating mesh 6 was manufactured in the form of mutually connected convex hexagons with the dimensions of 1 = 12.47 mm, k = 13.62 mm, n = 4.63 mm, and m = 2.4 mm. Surface current density was constant throughout the entire electrically conductive heating mesh. The electrically conductive heating mesh 6 was powered by the first heating electrode 2 and the second heating electrode 4. The first heating electrode 2 was connected by a conductor avia the NO switch of a relay 5 to a phase conductor L of a controllable thermostat R connected to electric power supply. The second heating electrode 4 was connected by a conductor b to the neutral conductor N of the electric power supply, which was, via a winding C of the relay 5, connected by a conductor c via a safety electrode 3 with the phase conductor L, led in the chamber inside the frame via a magnetic contact M connected to the electricity supply network by a conductor d to the phase conductor L, which was led via the con trollable thermostat R. The safety electrode 3 had the width of 1 mm. A temperature sensor T was connected to the thermostat R by a conductor e; the temperature sensor T was positioned at the edge of the glass substrate 1; the controllable thermostat R was further connected to the control unit in the electrical control panel. The conductors a, b, c, d, and e were led between the movable and fixed frame by an armoured grommet 13. In addition, the NC contact of the relay 5 was connected to the DIx digital input of the control system. The glass substrates 1, 7 were installed at a mutual distance of 9 mm, depending on the width of the chamber 9, delimited by a plastic spacer frame 8 with the cross-section in the shape of rectangle with bevelled comers. The base V of the rectangle was fitted with a moisture- stop aluminium coat H. The bevel Z of the rectangle was up to a half of its length adjacent to the base V fitted with the same moisture- stop aluminium coat H. The plastic spacer frame 8 was filled with a synthetic crystalline aluminosilicate-based molecular sieve with a three-dimensional system of pores with the diameter of 0.29 nm. The plastic spacer frame 8 was along the vertical sides X of the rectangle attached to the substrates 1, 7 by permanently flexible non conducting polyisobutylene-based binding material 11. On the side of the base V and bevel Z, the plastic spacer frame was attached to the substrates 1, 7 by two-part poly- sulphide-based fixing sealant 10.

[0028] In addition, a variant of this heating safety window with a chamber 9 filled with

krypton was manufactured.

[0029] Example 2

[0030] An example of embodiments of the heating safety window is provided in Fig. 1, Fig.

5, and Fig. 7.

[0031] A heating safety window with a sliding wooden frame D with the size of h = 2,200 mm and s = 1,100 mm, positioned on the side s on guide rails of a fixed wooden frame was manufactured. The frame D was fitted with two flat glass substrates 1, 7 with the size of h = 2,100 mm and s = 1,000 mm manufactured from monolithic soda- lime glass with the thickness of 8 mm, comprising 70% by weight of Si02, 13% by weight of Na20, 10.0% by weight of CaO, 5% by weight of MgO, 0.75% by weight of A1203, 0.14% by weight of K20, 0.27% by weight of S03, and 0.84% by weight of other added substances. The glasses were separated by the chamber 9 filled with argon. The flat glass substrate 7 was fitted with a reflective layer 12 with the emissivity of 0.03. The flat glass substrate 1 was hardened and on its inner side fitted with an electrically conductive heating mesh 6 with the thickness of 100 nm, made of Sn02:F, the trans- missivity of which in the visible region was 79%, ultraviolet radiation opacity was 86%, and the infra-red radiation reflectivity was 59%. The electrically conductive heating mesh 6 was manufactured in the form of mutually connected equilateral triangles with the dimensions of 1 = 51 mm, n = 3.5 mm, and m = 3.5 mm. Surface current density was constant throughout the entire electrically conductive heating mesh 6. The electrically conductive heating mesh 6 was powered by the first heating electrode 2 and the second heating electrode 4. The first heating electrode 2 was connected by a conductor a via the NO switch of a relay 5 to a phase conductor L of a thermostat R connected to electric power supply. The second heating electrode 4 was connected by a conductor b to the neutral conductor N of electric power supply, which was via the winding C of the relay 5 connected to a conductor c via a safety electrode 3 with a phase conductor led in the chamber in the frame via a magnetic contact M connected to the electricity supply network by a conductor d to the phase conductor L, which was led via a controllable thermostat R. The controllable thermostat R was fitted with, by a conductor e, a temperature sensor T which was positioned at the edge of the substrate 1, and the controllable thermostat R was also connected to the control unit in the electrical control panel. The conductors a, b, c, d, and e were between the moving and fixed frames connected via a connector K. In addition, the NC contact of the relay 5 was connected to the digital input DIx of the control system. The glass substrates 1, 7 were installed at a mutual distance of 30 mm, depending on the width of the chamber 9, delimited by a plastic spacer frame 8 with the cross-section in the shape of rectangle with bevelled corners. The base V of the rectangle was fitted with a moisture-stop aluminium coat H. The bevel Z of the rectangle was up to a half of its length adjacent to the base V fitted with the same moisture- stop aluminium coat H. The plastic spacer frame 8 was filled with a synthetic crystalline aluminosilicate -based molecular sieve with a three-dimensional system of pores with the diameter of 0.31 nm. The plastic spacer frame 8 was along the vertical sides X of the rectangle attached to the substrates

I, 7 by permanently flexible non-conducting polyisobutylene -based binding material

I I. On the side of the base V and bevel Z, the plastic spacer frame was attached to the substrates 1, 7 by two-part polysulphide-based fixing sealant 10.

[0032] Example 3

[0033] An example of embodiments of the heating safety window is provided in Fig. 2, Fig.

5, and Fig. 8..

[0034] A heating safety window with a sliding wooden frame D with the size of h = 2,200 mm and s = 1,900 mm, positioned on the side s on guide rails of a fixed wooden frame was manufactured. The frame D was fitted with three flat glass substrates 1, 14, and 7 with the size of h = 2,100 mm and s = 1,800 mm manufactured from monolithic soda- lime glass with the thickness of 4 mm, comprising 70% by weight of Si02, 14% by weight of Na20, 10.0% by weight of CaO, 4% by weight of MgO, 0.75% by weight of A1203, 0.1% by weight of K20, 0.25% by weight of S03, and 0.9% by weight of other added substances. The glasses were separated by chambers 9 filled with argon. The flat glass substrates 7 14 were fitted with a reflective layer 12 with the emissivity of 0.03. The flat glass substrate 1 was hardened and on its inner side fitted with an electrically conductive heating mesh 6 with the thickness of 25 nm, made of Sn02:F, the transmissivity of which in the visible region was 82%, ultraviolet radiation opacity was 85%, and the infra-red radiation reflectivity was 58%. The electrically conductive heating mesh 6 was manufactured in the form of regular equilateral quadrangle with the dimensions of 1 = 105 mm, k = 105 mm, n = 5.6 mm, and m = 5.6 mm. Surface current density was constant throughout the entire electrically conductive heating mesh 6. The electrically conductive heating mesh 6 was powered by the first heating electrode 2 and the second heating electrode 4. The first heating electrode 2 was connected by a conductor avia the NO switch of a relay 5 to a phase conductor L of a controllable thermostat R connected to electric power supply. The second heating electrode 4 was connected by a conductor b to the neutral conductor N of electric power supply, which was via the winding C of the relay 5 connected to a conductor c via a safety electrode 3 with a phase conductor L led in the chamber in the frame via a magnetic contact M connected to the electricity supply network by a conductor d to the phase conductor L, which was led via a controllable thermostat R. The controllable thermostat R was fitted with, by a conductor e, a temperature sensor T which was po sitioned at the edge of the substrate 1, and the controllable thermostat R was also connected to the control unit in the electrical control panel. The conductors a, b, c, d, and e were between the moving and fixed frames connected via a connector K. In addition, the NC contact of the relay 5 was connected to the digital input DIx of the control system. The glass substrates 1, 14 and 14, 7 were installed at a mutual distance of 16 mm, depending on the width of the chambers 9, delimited by plastic spacer frames 8 with the cross-section in the shape of rectangle with bevelled comers. The base V of the rectangle was fitted with a moisture-stop aluminium coat H. The bevel Z of the rectangle was up to a half of its length adjacent to the base V fitted with the same moisture-stop aluminium coat H. The plastic spacer frames 8 were filled with a synthetic crystalline aluminosilicate-based molecular sieve with a three-dimensional system of pores with the diameter of 0.31 nm. The plastic spacer frames 8 were along the vertical sides X of the rectangle attached to the substrates 1, 14 and 14, 7 by per manently flexible non-conducting polyisobutylene-based binding material 11. On the side of the base V and bevel Z, the plastic spacer frames were attached to the substrates 1, 14 and 14, 7 by two-part poly sulphide-based fixing sealant 10.

[0035] Example 4 [0036] An example of embodiments of the heating safety window is provided in Fig. 3, Fig. 4, and Fig. 9.

[0037] A heating safety studio window with a swivel-mounted wooden frame D with the size of h = 1,200 mm and s = 900 mm, connected with a fixed wooden frame on the side s using two hinge plates was manufactured. The frame D was fitted with three flat glass substrates 1, 14, and 7 with the size of h = 1,100 mm and s = 800 mm manu factured from monolithic soda- lime glass with the thickness of 4 mm, comprising 71% by weight of Si02, 13% by weight of Na20, 9.5% by weight of CaO, 5% by weight of MgO, 0.7% by weight of A1203, 0.14% by weight of K20, 0.27% by weight of S03, and 0.39% by weight of other added substances. The glasses were separated by chambers 9 filled with argon. The flat glass substrate 14 was fitted with a reflective layer 12 with the emissivity of 0.03. The flat glass substrate 1 was hardened and on its inner side fitted with an electrically conductive heating mesh 6 with the thickness of 20 nm, made of Sn02:F, the transmissivity of which in the visible region was 83%, ul traviolet radiation opacity was 85%, and the infra-red radiation reflectivity was 58%. The electrically conductive heating mesh 6 was manufactured in the form of mutually connected convex hexagons with the dimensions of 1 = 12.47 mm, k = 13.62 mm, n = 4.63 mm, and m = 2.4 mm. Surface current density was constant throughout the entire electrically conductive heating mesh. This electrically conductive heating mesh was powered by the first heating electrode 2 and the second heating electrode 4. The first heating electrode 2 was connected by a conductor a via the NO switch of a relay 5 to a phase conductor L of a thermostat R connected to electric power supply. The second heating electrode 4 was connected by a conductor b to the neutral conductor N of electric power supply, which was via the winding C of the relay 5 connected to a conductor c via a safety electrode 3 with the phase conductor L led in the chamber in the frame via a magnetic contact M connected to the electricity supply network by a conductor d to the phase conductor L, which was led via a controllable thermostat R. The thermostat R was fitted with, by a conductor e, a temperature sensor T which was positioned at the edge of the substrate 1, and the controllable thermostat R was also connected to the control unit in the electrical control panel. The conductors a, b, c, d, and e were led between the movable and fixed frame by an armoured grommet 13. In addition, the NC contact of the relay 5 was connected to the DIx digital input of the control system.

[0038] The glass substrates 1, 14 and 14, 7 were installed at a mutual distance of 16 mm, depending on the width of the chambers 9, delimited by plastic spacer frames 8 with the cross-section in the shape of rectangle with bevelled comers. The base V of the rectangle was fitted with a moisture- stop aluminium coat H. The bevel Z of the rectangle was up to a half of its length adjacent to the base V fitted with the same moisture- stop aluminium coat H. The plastic spacer frames 8 were filled with a synthetic crystalline aluminosilicate-based molecular sieve with a three-dimensional system of pores with the diameter of 0.31 nm. The plastic spacer frames 8 were along the vertical sides X of the rectangle attached to the substrates 1, 14 and 14, 7 by per manently flexible non-conducting polyisobutylene-based binding material 11. On the side of the base V and bevel Z, the plastic spacer frames were attached to the substrates 1, 14 and 14, 7 by two-part poly sulphide-based fixing sealant 10.

[0039] In addition to heating, the heating glass also fulfils the security function as a sensor of unauthorized breaking and entering. When the glass is broken, electric current flowing in the inner glass substrate of the insulation glass is interrupted. The heating control system detects the interruption of electric current flow and may raise an alarm. No additional installation of shock window sensors is required. Such sensors do not look good anyway and in addition to power sully cables they require other signal cables.

Industrial Applicability

[0040] The heated safety glazing has a wide applicability in all types of structures. It can be implemented for example as standard and roof window, glazing for winter gardens, swimming pool or terrace.