Technical field

The present invention relates to the field of transport safety, in particular, to a type of glass breaking device used in a transport vehicle.

Prior art

There have been many casualties in recent years as a result of passengers trapped in and failing to evacuate quickly from vehicles involved in serious incidents including outbreak of fire, flash flooding or storms. Transport safety has increasingly become a matter of top concern among commuters, who either take public transport or drive. In the event of an emergency, the ability to escape from the relatively enclosed environment of a vehicle interior becomes critically important. Both the lives of the passengers and drivers, and the safety of their property, will be in danger if measures are not taken in time, or the essential self-rescue precautions are not in place. Consequently, at present, the transport industry and manufacturers mostly consider the provision of an escape route made available in an emergency by the glass walls or windows being broken as one of the effective measures in preventing heavy casualties in serious incidents.

Currently there are a wide variety of glass breaking devices available such as manual break-glass hammers, electromagnetic break-glass hammers and highly compressed gas generators. These glass breaking devices all operate on the principle of hitting the glass at speed with sharp hard objects, which break its surface tension, thereby shattering the glass. Currently, however, given the level of skills required of a person to break the glass with a manual hammer, passengers may not be able use a manual hammer or end up spending too much time breaking the glass as a result of injuries or being confined to a limited space, while it is possible that electromagnetic hammers or highly compressed gas generators may fail to break the glass if it is double-glazed. Even if the glass is successfully broken, the flying of sharp shards from the breakage may injure people in the vicinity of the vehicle windows, and as they are located at a height close to people's face and head, any injury caused could be rather serious.

Scope of the invention

In view of the existing issues with the current technologies, the present invention provides a type of glass breaking device capable of breaking glass within an acceptable space of time even when it is double-glazed, without causing jagged shards flying around.

A type of glass breaking device is provided according to one aspect of the present invention. The glass breaking device may include at least one gas generator and a controller. The said gas generator is provided within the said glass and comprises a sealed cavity configured to accommodate a gas generant that produces a highly compressed gas upon excitation by electric currents, like known as gasgenerators for airbags in Passenger Safety, but with adapted amounts of gas volume and expansion time. The said controller is connected to at least one of the said gas generators by a lead wire and configured to respond to an activating signal, generating the current required for the excitation of the said gas generant.

In one embodiment, at least one of the said gas generators is provided near the edge of the said glass.

6 In one embodiment, the said gas generant is a type of gunpowder sensitive to electric currents.

In one embodiment, the melting point of the said sealed cavity is higher than that of the said glass.

In one embodiment, the said sealed cavity is made of metal.

In one embodiment, the said controller is configured to receive the said activating signal by wired or wireless communication.

In one embodiment, the said lead wire is in contact with the said gas generant by entering the said sealed cavity.

In one embodiment, the said glass breaking device further comprises an actuator connected to the controller with wire or wirelessly and configured to emit the said activating signal.

In one embodiment, the said glass breaking device is installed in a vehicle, wherein the said actuator is provided on the driver's console of the said vehicle or near a passenger seat or a window.

In one embodiment, the wireless connection of the said actuator and the said controller is based on Bluetooth, near-field communication or Wi-Fi protocols.

The gas generator according to the embodiment of the present invention may be embedded into the glass interior. Upon deformation of the sealed cavity by the highly compressed gas generated within the glass, the stress in the glass is released, making the glass break quickly. The glass shatters preferably (nearly) completely even when it is double-glazed, and by controlling the amount of gas generant 122 filled, but flying of jagged shards can be avoided. So there are preferably no shards flying around as a result of the breakage. The glass breaking device of the present invention is suitable for use on different means of transport including vehicles, trains and ferries.

7 Further aspects and scope for adaptation are made clear in the description provided herein. It should be understood that aspects of the present application may be implemented alone or in combination with one or more other aspects. It is also to be understood that the description and specific embodiments herein are intended for purposes of illustration only and are not intended to limit the scope of the application.

Description of the drawings

The drawings described herein are for purposes of illustrating the selected embodiments only but not all possible embodiments, and are not intended to limit the scope of this application, wherein:

Figure 1 shows a schematic diagram of the glass breaking device according to an embodiment of the present invention;

Figure 2 shows a schematic diagram of an application embodiment of the glass breaking device according to an embodiment of the present invention;

Figure 3 shows a schematic diagram of another application embodiment of the glass breaking device according to an embodiment of the present invention.

Details of embodiments

The drawings will be referred to in conjunction with the embodiments hereafter in the detailed description of the present invention. It should be noted that, where there is no conflict, the features of the embodiments of the present invention may form different permutations.

Figure 1 shows a schematic diagram of the glass breaking device 10 according to an embodiment of the present invention. As shown in Figure 1 , the glass breaking device 10 may comprise at least one gas generator 12 and a controller 14. The gas generator 12 is provided within glass 11 and comprises a sealed cavity 121, which is configured to accommodate a gas generant 122 that

8 produces a highly compressed gas upon excitation by electric currents. The controller 14 is connected to at least one gas generator 12 by a lead wire 13 and is configured to respond to an external activating signal, generating the current required for the excitation of the gas generant 122.

In an exemplary embodiment, the glass breaking device 10 may be installed in a vehicle. When the glass needs to be broken, an activating signal may be sent to the controller 14. Upon receipt of the activating signal by the controller 14, an electrical current is generated to break the glass. The current passes through the lead wire 13 and produces heat as a result of the resistance of the wire, known as joule heating, which in turn causes the gas generant 122 to combust and produce a highly compressed gas. While the current generated for glass breaking is relatively weak, accumulation of energy on the lead wire 13 in time will eventually bring about the combustion of the gas generant 122 and consequently production of a highly compressed gas. The presence of a highly compressed gas then causes the deformation of the sealed cavity 121 and releases the internal stress of the glass 1 1 so that it is broken quickly.

In this embodiment, the gas generator 12 may be provided near the edge of glass 1 1. The stress distribution in glass 1 means that it can be broken more easily. It is understood that one or more of the said gas generators 12 may be provided, all of which are connected in parallel to the controller 14.

In this embodiment, the melting point of the sealed cavity 121 is higher than that of glass 1 so that the former may be implanted into the latter in its tempering process. Specifically, the sealed cavity 121 may be made of metal such as aluminum and steel. It should be understood that the sealed cavity 121 may also be made of a material other than metal provided that it has a melting point higher than that of glass 1 1 and has a certain degree of hardness.

9 In this embodiment, the gas generant 122 may be a type of gunpowder sensitive to electric currents, for example, a gas generant of the same type as the one used in safety gas bags in vehicles. Specifically, the gas generant 122 may include, among others, compacted smokeless gunpowder (nitrocellulose) or compacted non-azide compounds constituted of organic nitrogen compounds and oxidising agents. The amount of gas generant 122 to be filled may be determined by various parameters of glass 1 1 including, among others, its type and size, such that glass 1 1 just cracks and its surface fractures without causing any flying of jagged shards. It should be understood that a person skilled in the art, based on the guidance provided herein, may use various forms of gas generants such as those known in the art.

I n this embodiment, the lead wire 13 comes into contact with the gas generant 122 by entering the sealed cavity 121 so as to ignite the gas generant 122, which then produces a highly compressed gas. In addition, in another exemplary embodiment, the glass breaking device 10 may also be applied in glass 1 1 , double- or multi-glazed. Gas generators 12 installed in the each of the layers of the multi-glazed glass 1 1 are connected in parallel to the controller 14. Upon receipt of an activating signal from the controller 14, a glass breaking current is generated, thereby exciting the gas generant 122 to produce a highly compressed gas. The highly compressed gas causes deformation of the sealed cavity 121 in each layer of glass 1 1, thereby shattering each glass layer.

In this embodiment, the gas generator 12 of the glass breaking device 10 is embedded into the glass interior. Upon deformation of the sealed cavity by a highly compressed gas generated following excitation of the gas generant 122 by electric currents within the glass, the stress within the glass is released, making the glass break quickly. By controlling the amount of gas generant 122 filled, flying of jagged shards can be (mostly) avoided, thereby preventing or mitigating any harm or injuries caused by the breakage of vehicle windows.

10 Figure 2 shows schematically a schematic diagram of another application embodiment of the glass breaking device according to an embodiment of the present invention. In this embodiment, the glass breaking device 10 is installed in a vehicle, whereas the controller 14 is connected with the actuator 15 with wire. The actuator 15 is provided on the driver's console of the said road vehicle or near a passenger seat or a window. When the glass needs to be broken, the driver or a passenger sends an activating signal by pressing the actuator 15. In this embodiment, upon receipt of the activating signal from the controller 14 through wired connection, a glass breaking current is generated, thereby exciting the gas generant 122 to produce a highly compressed gas. The highly compressed gas causes deformation of the sealed cavity 121 in glass 11, thereby shattering it quickly.

It should be understood that a person skilled in the art, based on the guidance provided herein, may integrate the controller 14 and the actuator 15 into a single component.

Figure 3 shows schematically a schematic diagram of another application embodiment of the glass breaking device according to an embodiment of the present invention. In this embodiment, the glass breaking device 10 is installed in a road vehicle, whereas the controller 14 is connected with the actuator 15 wirelessly. Communication between the controller 14 and the actuator 15 is based on Bluetooth, near-field communication (NFC) or Wi-Fi protocols. The actuator 15 is provided on the driver's console of the said road vehicle or near a passenger seat or a window. When the glass needs to be broken, the driver or a passenger sends an activating signal by pressing the actuator 15. In this embodiment, upon receipt of the activating signal by the controller 14 through wireless connection, a glass breaking current is generated, thereby exciting the gas generant 122 to produce a highly compressed gas. The highly compressed gas causes deformation of the sealed cavity 121 in glass 11, thereby shattering it

11 quickly. By using wireless control, the device may be installed conveniently since concerns over the layout of electrical wiring in the vehicle are no longer an issue.

It should be understood that the present invention does not break glass by applying the principle of impact by sharp hard objects but to cause deformation of the sealed cavity embedded within the glass, thereby breaking the glass quickly with the release of internal stress. Furthermore, by controlling the amount of gas or the time and/or velocity of generation, the pressure exerted by the gas may be limited such that the glass cracks, its surface fractures but stops short of producing flying shards, thereby eliminating or mitigating the risks of injury as a result of glass breakage.

Furthermore, the said window breaking device according to the present invention has a wide range of applications; not only can it be applied in automotive vehicles, it can also be applied in other transport vehicles such as trains and ferries for opening vehicle doors and roof windows etc.

The foregoing gives only the preferred embodiments of the present invention and does not pose any limitation to the present invention; to those who are skilled in the art, the present invention may have various alterations and variations. All the modifications, equivalent replacements or improvements in the scope of the present invention shall all be included within the scope of protection of the present invention.

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