GB2281708A - A hammer for breaking double-glazed windows - Google Patents

Abstract

A device adapted for the breakage of double glazed windows of the type including a first and second pane of glass, is provided. The device comprises a weighted head 1 attached to a supporting arm 2; characterized in that the weighted head 1 comprises: (i) a sharp pointed element 3 capable of piercing the first pane of glass; (ii) resilient means 5 connecting with said piercing element 3 and housed, at least partially, within said head 1 and so formed that it can be compressed only slightly before becoming locked in a fixed position, whereupon on breakage of said first pane by said pointed element 3, said resilient means 5 drives the pointed element 3 towards the second pane thereby facilitating its breakage. <IMAGE>

Description

DEVICE FOR BREAKING DOUBLE GLAZED WINDOWS This invention relates to a device which facilitates emergency exit from buildings fitted with double glazed windows.

Legislation has been introduced in Great Britain to reduce deaths from people trapped during fires in rooms fitted with fixed or jammed double glazing. This new legislation calls for hinged double glazed windows wherever a new installation is being carried out, to allow ease of escape in the event of a fire or similar hazard.

Ever since double glazing became fashionable, both "Do it yourself' and professional installers have fitted fixed double glazed units rather than opening windows for reasons of economy and/or security from intruders. Many of these installations remain, and people are still dying trying to escape through these windows because of the difficulty experienced in breaking them with articles normally found in a room.

Even an ordinary hammer or 'blunt instrument' cannot break through fixed double glazing because the air cushion inside the sealed unit absorbs any blow and the subsequent recoil makes the hammer simply bounce off.

Ordinary room furniture like a television or a telephone thrown at the window has even less chance of breaking the units. Thus, in the event of fire or similar hazard which requires the room's occupants to escape, double glazing can prove to be a death trap.

The device according to the invention is designed to provide a reliable means of effecting exit through double glazed windows thereby alleviating the above mentioned problems.

Thus, in accordance with the invention, there is provided a device adapted for the breakage of double glazed windows of the type including a first and second pane of glass, which device comprises a weighted head attached to a supporting arm; characterized in that the weighted head comprises: (i) a sharp pointing element capable of piercing a pane of glass on contact; (ii) resilient means connecting with said pointed element and housed, at least partially, within said head, and so formed that it can be compressed only slightly before becoming locked in a fixed position, whereupon on breakage of said first pane by said pointed element, said resilient means drives the pointed element towards the second pane thereby facilitating its breakage.

In accordance with a second embodiment of the invention there is provided a method of breaking a double glazed window of the type including a first and second pane of glass, utilizing a device as described above by swinging the device so as to contact the pointing element with the first pane of glass, the contact causing compression of the resilient means to a fixed position and breakage of the first pane, whereupon rupture of the first pane of glass then releases the compression of the resilient means so that the piercing element is driven into the second pane of glass thereby facilitating its rupture.

Preferably the resilient means is a coil spring and the pointed element is a centre punch.

Reference will now be made, by way of example, to the accompanying drawings which illustrate the principle of design of a piercing instrument according to the invention. The device will be referred to by the trade name "Glazebuster." The Glazebuster is made from a 1" square solid section steel bar (1) approximately 12" long mounted on the end of a long bright drawn high tensile strength steel shaft (2) approximately 36" long and 1/2" in diameter. The shaft is positioned approximately 1" from the back end of the square bar section.

Mounted into the front face of the square bar section is a sharp pointed centre punch (3), centre outwards, sliding in a split pin bush (4), which also retains a partially compressed high compression spring (5) in contact with the flat end of the centre punch. The centre punch can be depressed into the bushlspring assembly by a force greater than the spring pressure. The point of the centre punch is prevented from being depressed fully by the dimensions of the drilled recess. The point projects by approximately 0.25" when the spring becomes "coil bound". Once the force on the point is released by breakage of the first pane of glass, the depressed centre punch is fired back out by the spring.

The dimensions of the Glazebuster allow the user to stand back, close to the wall, adjacent to the window being broken, to strike the window with the tool and be far enough from any falling shattered glass to escape serious injury. The quoted dimensions of the Glazebuster are an example chosen for normal UK household 24mm thick double glazed units. The dimensions can be modified for other glass thickness and air gap separation.

The unit will preferably be painted fire red.

When the Glazebuster is swung, centre punch point first, at the corner of a double glazed window, the centre punch contacts the first pane of glass and is pushed back into the square section bar by the glass force deflecting the high compression spring.

On full spring compression, and with the full weight of the Glazebuster now being applied, the centre punch point overcomes the glass resistance and pierces the first panel of glazing causing the pane to fracture at that point and the unit's air cushion to be inoperative. The body of the Glazebuster will continue to travel at a slightly reduced velocity to fracture a major portion of the now ruptured first glass pane.

As the first pane fractures, the load on the centre punch will be released and the punch will be fired by the compressed spring into the second pane, which is similarly fractured. The motion of the Glazebuster continues through and breaks up the second pane. Thus, in one swing of the Glazebuster, both panes of the double glazed window unit may be breached.

The Glazebuster can then be turned round and grasped by the square bar end. The handle end of the long shaft can then be used to push and break out the rest of the glass with reduced risk of injury from falling splinters of glass.

Claims (5)

1. A device adapted for the breakage of double glazed windows of the type including a first and second pane of glass, which device comprises a weighted head attached to a supporting arm; characterized in that the weighted head comprises: (i) a sharp pointed element capable of piercing the first pane of glass; (ii) resilient means connecting with said piercing element and housed, at least partially, within said head and so formed that it can be compressed only slightly before becoming locked in a fixed position, whereupon on breakage of said first pane by said pointed element, said resilient means drives the pointed element towards the second pane thereby facilitating its breakage.

2. A method of breaking a double glazed window of the type including a first and second pane of glass, utilizing a device as claimed in claim 1 by swinging the device so as to contact the piercing element with the first pane of glass, the contact causing compression of the resilient means to a fixed position and breakage of the first pane, whereupon rupture of the first pane of glass then releases the compression of the resilient means so that the pointed element is driven into the second pane of glass thereby facilitating its rupture.

3. A method or device according to claim 1 or 2 wherein the resilient means is a coil spring.

4. A method or device according to claim 1 or 2 wherein the pointed element is a centre punch.

5. A method or device substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.