GB2263930A

GB2263930A - Window safety device

Info

Publication number: GB2263930A
Application number: GB9302440A
Authority: GB
Inventors: Christopher Edward Meddins
Original assignee: YOUNG JAYNE
Current assignee: YOUNG JAYNE
Priority date: 1992-02-08
Filing date: 1993-02-08
Publication date: 1993-08-11
Anticipated expiration: 2013-02-08
Also published as: GB9202674D0; GB9302440D0; GB2263930B

Abstract

A safety device for use on a double-glazed window having a pair of panes (3, 4) separated by a space (5), includes a body (8) for engagement with one (4) of the panes, a glass penetrating element (9) carried by the body and normally held retracted from the pane, and means (11) operable to drive the element (9) into penetrative impact with the pane (4). The element may alternatively be explosively driven. <IMAGE>

Description

WINDOW SAFETY DEVICE This invention relates to a safety device for use with double-glazed windows and especially with sealed double-glazed units which are formed by a pair of panes of glass arranged with a gap between them which is usually partially evacuated. The invention also embraces a double-glazed unit incorporating such a safety device.

A conventional sealed double-glazed unit installed in a window frame has been found to be often very difficult to break, even by the application of severe impact blows, such as by the use of a hammer or heavy items such as furniture for example. This is because the trapped air between the panes acts to cushion the effect of the impact and allows the glass to flex without breaking. Danger therefore can arise, in the event of a fire, for the occupants of a room equipped with such windows, since exit through the windows can be difficult, if not impossible, with the attendant risk of the occupants being overcome by flames or fumes.

An object of the present invention is to provide a safety device, as well as a double-glazed window unit equipped with such a device, which enables the window readily to be broken in the event of an emergency, such as a fire, in order to permit exit through the window by the occupants of a room.

According to the invention a safety device for use on a double-glazed window having a pair of panes separated by a space comprises a body for engagement against one of the panes, a glass penetrating element carried relative to the body and normally retained in a retracted position, and means operable to drive the element into penetrative impact with the pane.

In a preferred embodiment of the invention, the body is generally tubular and houses the glasspenetrating element.

Conveniently, the plunger extends to the exterior of the housing for the application of external impact thereon. Alternatively, the glass-penetrating element may be explosively actuated.

From another aspect of the invention, a doubleglazing unit has the aforesaid safety device attached to one of the panes thereof in a non-central area of the unit, such that actuation of the impact means causes the glass-penetrating element to penetrate the pane of glass to which the device is attached.

The invention will now be described, by way of example, with reference to the accompanying drawings in which:- Figure 1 is a cross-sectional view of one form of the window safety device of the invention taken along the line B-B of Figure 2; Figure 2 is a section along the line A-A of Figure 1; Figure 3 is a fragmentary perspective view of part of a window double-glazed window unit incorporating a safety device of the invention; Figure 4 is a cross-sectional view of an alternative form of the safety device of the invention, and Figure 5 is a view similar to Figure 3 showing the device of Figure 4 incorporated in a window double glazing unit.

Referring to Figure 1, the safety device 1 therein is shown incorporated in a sealed double-glazed unit 2 having a pair of glass panes 3 and 4 separated by a partially evacuated space 5. The safety device would normally be attached to the internal one 4 of the panes although its use on an external pane is not excluded.

The device 1 includes a hollow generally tubular body 6, one end portion 7 of which is of larger diameter than the remainder and forms a chamber 7A, for the purpose to be described. The outer end of the chamber is formed with a peripheral flange 7B which is secured to the pane 4, as by bonding or glueing. The end of the chamber 7A adjacent its flange is open until closed by attachment of the device to the window. Slidably mounted within the body 6 is a plunger 8 which has a hardened glass-penetrating element in the form of a pin 9 fixed in a longitudinal bore within the plunger and having a sharpened glass-penetrating end portion 10 extending from the inner end of the plunger towards the unit 2.The other end of the plunger extends outwardly of the other end of the housing 6 and is provided with a knob or button 11 enabling the device to be manually operated in the manner to be described. The plunger is held in its illustrated retracted position by a spring 12 which in the case illustrated, acts between the outer end of the housing and an internal surface of the knob. The knob may be provided with a coloured insert llA for decorative or recognition purposes.

A retention disc 13 is secured to the inner end of the plunger 8 by welded rivets for example, one of which can be seen at 14. The plunger is urged by the spring 12 against an internal shoulder 15 of the body. An annular rib 16, or series of inwardly projecting protrusions lies forwardly of the shoulder 15, being spaced therefrom by the thickness of the disc 13, and acts to prevent accidental displacement of the plunger 8 from its illustrated rest position, and also to ensure that the pin 9 is normally held spaced from a window pane, in use.

This is important, since it provides more reliable penetration of the pane than if the pin were permanently engaged with the pane prior to impact. They also ensure that a substantial blow, sufficient to cause penetration of the window by the pin 9, has to be imparted to the button 11 in order to dislodge the plunger from the rib 16. Added security can be obtained by using a locking pin 6A, shown dotted in Figure 2, which requires removal prior to actuating the device.

As can be seen from Figure 2, the plunger 8 is formed with equi-angularly spaced longitudinal channels 8A, four of which are provided in the illustrated example, although this may be varied as required. The channels extend from the free end of the body to the location of the disc 13 and are aligned with holes 8B through which communication takes place between the chamber 7A and the exterior of the device via the channels 8A.

In use, the safety device 1 is secured to a corner area of the inner glass pane 4, since this is a particularly stiff area susceptible to penetration by the pin 10.

The double-glazed unit of the invention provides an added degree of safety for the occupants of a room in which one or more of the units is installed. Thus for example, in the event of an emergency, such as a fire, necessitating exit through a window, the double-glazing unit may readily be broken by applying a sharp impact to the plunger 8 of the device 1, causing the pin 10 to pass through the chamber 7A and fracture the adjacent glass panel. This permits escape of air from or into the units, such air being conducted via the channels 8A from or to the exterior. Once this has occurred, the panes of glass 3 and 4 may be readily smashed employing any means readily to hand such as an item of furniture for example.

The device may additionally incorporate a split collar or other suitable means, acting between the plunger and housing in order to provide further security against accidental operation of the device.

It will be understood that the device of the invention may take many alternative forms, without departing from the scope of the invention. For example, the spring may be omitted and the plunger retained in its retracted position by interengaging formations respectively on the plunger and housing which may snapengage to provide positive retention but be readily overcome by impact upon the plunger 8. The pin may be attached directly to the knob 11 and slide against the internal wall of the housing.

In an alternative arrangement, to that first described, a small explosive charge may be incorporated, for example, between the impact knob and the penetrating elements, to enable the device to be activated by a relatively light blow as might be administered by a child or relatively infirm adult.

In the further embodiment of Figures 4 and 5, the unit 50 can be seen attached to a pane 49 of a double glazing unit 2, as previously described. The manually operated plunger of Figures 1 and 3 is replaced by a hollow body 51 containing a glass-penetrating plunger 52, a head of which is slidably guided within the body, the plunger being arranged opposite to a very thin wall portion 54 of the body. A quantity of explosive 55 is contained within the body behind the head and an electrically heated coil 56 is in heat-transmissible contact with the explosive. The coil is controlled by leads 57 to a battery 58 via a switch 59.The switch is normally covered by a pane of glass 60 which may readily be broken, upon the occurrence of a fire for example, to permit closing of the switch and firing of the explosive, which causes the plunger 52 to penetrate the pane 4, so that the window may be readily broken. The unit 50 may be provided with holes (not shown) to permit the flow of air into or out of the unit as described previously. The device may alternatively be arranged so that the explosive is fired by manual impact, if required.

The electrically operated device may be incorporated into a fire safety system in which the explosive is fired automatically in the event of a fire.

Such a system may also incorporate automatic sprinklers and other devices.

All embodiments of the device of the invention may be supplied in a form suitable for attachment to existing double-glazed unit, or incorporated in such units during manufacture.

Claims

1. A safety device for use on a double-glazed window having a pair of glass panes separated by a space, comprising a body for engagement against one of the panes, a glass-penetrating element carried relative to the body and normally retained in a retracted position, and means operable to drive the element into penetrative impact with the pane.

2. A safety device according to Claim 1, wherein the body is generally tubular and houses the glasspenetrating element.

3. A safety device according to Claim 1, wherein the body houses a plunger carrying a glass-penetrating pin or the like, the plunger extending to the exterior of the housing for the application of external impact thereon.

4. A safety device according to Claim 3, wherein a passage is provided through the device between a location adjacent the impacting end of the element and the exterior, permitting air flow, in use, between the window space and atmosphere after penetration of the pane.

5. A safety device according to Claim 3 or Claim 4, wherein the body is spring-urged towards its inoperative retracted position.

6. A safety device according to Claim 4 or Claim 5, wherein the body forms a chamber in the region of the forward end of the element, the chamber communicating via the passage with the exterior.

7. A safety device according to Claim 1, wherein the body contains a quantity of explosive and a detonating device, actuation of which causes the detonation of the explosive to impel the element into penetrative impact with the pane.

8. A safety device according to Claim 7, wherein the detonator is electrically actuated.

9. A safety device substantially as hereinbefore described with reference to Figures 1 to 3 or Figures 4 and 5 of the accompanying drawings.

10. A double glazing unit incorporating a safety device according to any one of the preceding claims attached to one of the panes thereof in a non-central area of the unit, such that actuation of the impact means causes the glass-penetrating element to penetrate the pane to which the device is attached.

11. A safety system incorporating a safety device according to Claim 7, the device being connected into an electrical circuit to be activated in response to a fire or other indication.