GB2291110A - Security device - Google Patents

Abstract

A device is provided for opening a lock 16 from the outside of an outwardly opening door 10 (eg in a prison) when the mechanism has been jammed (eg by jamming the handle 17A on the inside of the door). The device 20 is in the form of a lever having a flattened head 21 which can be inserted between the door jamb at 14 and the edge of the door 10. The head 21 has a projecting beak 23 which can engage with the bevelled side 13 of the bolt 12 of the lock. The lever 20 can then be turned to pivot or roll on the bearing surface 24 against the inner edge of the door jamb. This brings the beak 23 forward and thereby forces the bolt 12 into the retracted position in the lock. <IMAGE>

Description

Security Device The present invention relates to security devices, and more specifically for devices for opening locked doors.

There are certain situations, particularly in various types of institutions, where there are doors with a specific combination of characteristics, as follows.

First, the doors are outward-opening; that is, the doors open by swinging outwardly from the room which they serve into a common or @public" space such as a corridor. Secondly, the doors have locks which are self-closing; that is, the door latches automatically as it is shut. (This is the normal action of a simple door lock.) Third, the door can be locked from the inside. Fourth, the lock mechanism includes only a single bolt, with the locking being achieved by effectively preventing the handle from turning.

In such situations, there may be a need for suitably authorized officials to be able to open such a door even when it is locked. The situation may be complacated by the possibility that the occupant of the room may have attempted to prevent such unlocking, eg by damaging the locking mechanism cto the extent that that is possible from inside the roomy or by jamming the handle against movement.

The lock mechanism may well be on the outside of the door, cr at any rate accessible from that side of the door. It will therefore be possible for an official to disassemble the lock mechanism to whatever extent is necessary to gain access to the bolt and unlock the door. However, this is obviously a fairly lengthy proceeding, and ir. some circumstances it may require the use cf one or more special screwdrivers @eg if the lock iS attached by means of security screws!.

The general @ icc of the present invention JE to provide an irnpr-ied technique for releasing such locks.

Considering such looks in more detail, the bolt of such a look is springloaded so that @t is normally in the extended p@sition. The end of the bolt. is bevelled s@ that wher the door la m@ved inte the @l@sed position, the bevele@ part of the bo@t strikes agai@st the stri@@r p@ate in the door jam@. This @esults in the bolt being forced into the retracted position in the lock, allowing the door to continue its closing.When the door is fully closed, the bolt springs out again to the extended position with its end engaging in the aperture in the striker plate, so latching the door shut.

The handle is coupled to the bolt by a mechanism which, in crude terms, can be described as @pull but not push", That is, turning the handle forcibly pulls the bolt into the lock to the retracted position, but the opposite movement of the bolt to the extended position is controlled by the spring loading the bolt; turning the handle back to the normal position only releases the bolt to be moved by the spring, but does not itself force the bolt to the extended position.

According to its main feature, the present invention provides a device for opening such a lock, comprising a lever having a flattened head which can be inserted between the door jamb and the edge of the door, the head having a projecting beak which can engage with the bevelled side of the bolt, and the lever being turnable to bring the beak forward and thereby force the bolt into the retracted position.

The invention also provides a method of opening such a lock, comprising inserting the head of a lever having a flattened head between the door jamb and the edge of the door, the head having a projecting beak which can engage with the bevelled side of the bolt, and turning the lever to bring the beak forward and thereby force the bolt into the retracted position.

A lever embodying the invention will now be described, by way of example, with reference to the drawing, which shows the lever together with a partial sectional view of a door.

The drawing shows the outer edge of, dcor IG which closes against a door jamb 11. The door has a lock mechanism If not shown in detail with handles 1 A and I-E, the mechanism including a bolt 12 which has a bevel 1@. The door jamb carries a striker plate 14 and has a recess 15 for receiving the bolt | 2; the striker plate 14 has an aperture metching the recess The bolt la normally projects from the edga of the door, in the extended position shown. When the door is @i@sed, the bevelle@ surface 1@ of the bolt strikes against the cuteu edge of the striker plate 14, and as the door is pushed shut, the striker plate rides up over the bevelled surface 13 and forces the bolt 12 to retract into the lock mechanism. Two handles 17A and 17B are coupled to the bolt 12 is a conventional manner which allows the bolt to retract without the handles having to move.When the door is fully closed, with its inner edge bearing against the rebate 18 of the door jamb 11, the bolt 12 returns to its extended position, as shown, as a result of its spring-loading in the lock mechanism. In this position, the end of the bolt 12 projects through the aperture in the striker plate and into the recess 13, so latching the door shut.

Once the door has closed, turning either of the handles 1 A and @B forces the bolt 12 to the retracted position, so unlatching the door and allowing it to open. Either of the handles may be turned; they are normally connected rigidly together so that both turn together.

It may happen that the occupant of the room locks the door. This can be done in various ways. The lock mechanism may incorporate locking means whereby the handle can be locked in position against turning. It may alse be possible for the occupant to leave a key device cof whatever sort is used, in the locking means, or to break the key device in the locking means or otherwise damage the mechanism. Further, the occupant may jam the handle @eg by means of a piece cf furniture@ to prevent it from being turned.

it may be necessary, in such circumstances, for an official to open the door from the outside. This can readily be acnieved by means of the lever 20 shown inside view. This lever has e head .i which is thin enough tc be inserted in the g@p between the edge of the door 10 and the door jamb 21, adjacent to the striker plate 14, and a handle 22 which may be of convenient thickness for comfortable h@@ding and use. The head has a proje@ting beak 23 as shown.

To open the lock, the head 21 is inserted between the door and the door jamb above the bolt 12, and is sh@ downwards untii it is in contaet with the bolt l@, with the beak 23 hying leve@ with and inwards of the bolt. The lever is then rotated about the couter edge 34 of the head @@ by raising the hand@e 23. The o@ter edge 24 is curved, es shown, to minimite damage to the door jemb. This durved bearing surface 24 beers agelinst the @ebate @@ of the door jemb. This res@lts in the beak 23 m@ving forwerds are @pwerds, engaging with the beve@ed s@rta@e @3 of the @@@t l@ er@ a@ f@r@@ing the @@@t @@ @@t@ the retrectes p@siti@@.

This movement of the bolt is sim@@ to its @@@emert @@ring the @@@@ si@sing of the door, and, as explained above, is not restrained by the handles.) When the bolt is fully retracted, the door is unlatched and can be pulled open in the usual way.

The curved bearing surface 24 is shown as forming a smooth continuation of the beak 23. It will of course be realized, however, that the operative elernents are the tip and adjacent front edge of the beak 23 which engage with the bolt of the lock, and the bearing surface which engages with the door jamb, and the precise conformation of the intermediate parts of the head 21 is of little significance as long as the requisite relationship between those operative parts is maintained.

It is evident that the opening of the door in this manner is virtually instantaneous. It can be achieved without the need for any access to the lock mechanism, and is effective regardless of the manner in which the occupant may have attempted to prevent the door from being unlocked.

The locl has been shown as having two handles 17A and 17B, one (17A) on the inside of the door and the other on the outside. In some circumstances, the door will have only one handle, 17A, on the inside, but no handle on the outside, being openable from the outside only by means of a key. The present invention is equally applicable to such a door.

Claims (6)

Claims

1 A device for opening a lock of the type described, comprising a lever having a flattened head which can be inserted between the door jamb and the edge of the door, the head having a projecting beak which can engage with the bevelled side of the bolt, and the lever being turnable to bring the beak forward and thereby force the bolt into the retracted position.

2 A device according to claim I wherein the rear edge of the beak forms a curved bearing surface.

3 A device substantially as herein described.

4 A method of opening a loci of the type described, comprising inserting the head of a device according to any previous claim between the door jamb and the edge of the door to engage the projecting beak of the heacl with tre bevelled side of the bolt, and turning the device to bring the beak forward and thereby force the bolt into tne retracted position.

5 A method of opening a lock of the type des@ribed, substantially as herein described.

6 Any novel and inventive feature or com@ination of features specifically disclosed herein within the meaning of Article 4H of the international Convention Paris Convent@en.