GB2277960A

GB2277960A - Locking system for doors and windows

Info

Publication number: GB2277960A
Application number: GB9409526A
Authority: GB
Inventors: Peter Richard Middleton-Smith
Original assignee: PLUS PLAN
Current assignee: PLUS PLAN
Priority date: 1993-05-12
Filing date: 1994-05-12
Publication date: 1994-11-16
Anticipated expiration: 2014-05-12
Also published as: GB9309704D0; GB2277960B; GB9409526D0

Abstract

A locking system is described for use with a window or door assembly comprising a window or door panel mounted in a frame and moveable from an open position to a closed position. The frame or panel is provided with a locking formation (4, 5) moveable from an unlocked position in which the window or door may be opened, to a locking position in which, when the panel is in the closed position, the window or door is locked. Locking means are being provided which move the locking formation (4, 5) from the unlocked position to the locking position in response to an external stimulus such as an impact upon, or sudden movement of, the window or door panel, or a signal from a remote transmitter. <IMAGE>

Description

Title: Locking Svstem for Doors and Windows This invention relates to locking mechanisms for doors and windows, in particular to remotely controlled or automatically operated systems providing added security.

Locking systems for windows commonly comprise locking elements, such as pins, provided on one edge of the window sash which locate in keeps on the corresponding internal face of the window frame. When the window is closed, the pins are moved by a manually-operable handle into locking engagement with the keeps, preventing opening of the window.

In view of heightened desire for domestic security, known locking systems of the type described above may be insufficiently effective. In particular, it may be desirable to provide locking elements on more than one edge of the window sash, but such an arrangement is difficult to realise in practice, since it necessitates a plurality of handles or complex mechanical linkages. Also, such an arrangement has the disadvantage that normal opening and closing may be time-consuming and cumbersome.

There has now been devised an improved form of locking system for doors and windows which overcomes or substantially mitigates the disadvantages of known systems.

According to the invention, there is provided a window or door assembly comprising a window or door panel mounted in a frame and moveable from an open position to a closed position, the frame or panel being provided with a locking formation moveable from an unlocked position in which the window or door may be opened, to a locking position in which, when the panel is in the closed position, the window or door is locked, and there being provided locking means operable to move the locking formation from the unlocked position to the locking position in response to an external stimulus.

The window or door assembly according to the invention is advantageous primarily in that it provides greater security than known windows or doors provided with known locking systems. In particular, a plurality of locking formations may be provided at more than one edge of a door or window panel without the need for more than one handle or complex mechanical linkages. Each locking formation may be in the unlocked position during normal use, being moved into the locking position only in response to the external stimulus. Normal operation is thus no more complex than with a conventional window or door.

It is an important feature of preferred embodiments of the invention that the locking formation is normally in the unlocked position, and the locking means acts to move the locking formation to the locking position only in the event of the external stimulus being detected.

The external stimulus which brings about actuation of the locking means may be an ultrasonic, radiofrequency or other signal. Such a signal may be generated by, for example, a suitable hand-held remote control unit. Movement of the locking formation from the unlocked to the locking positions in response to such a signal may be brought about by suitable electrical circuitry, eg involving a solenoid. For example, the locking formation may be a bolt which consists of the moving part of a cylindrical solenoid which moves in and out according to the electrical signal used to drive it. The bolt will move in one direction when supplied with a positive supply current and then back in the other direction when the electrical supply is reversed.

Alternatively, or in addition, the external stimulus may be an abuse of the window or door, eg by an impact or sudden movement as might occur during an attempted forced entry. To this end, there may be provided a sensor adapted to detect such an abuse, and appropriate circuitry to actuate the locking means in response to it. The sensor could be a piezoceramic sensor or proximity device to detect movement of the window sash.

Alternatively, the sensor could be a membrane type switch which would go open circuit in the event of the window being forced.

It is strongly preferred that there be provided means for overriding the locking system of the invention, so that it does not impede normal operation of the window during, for example, emergency egress. Such an override system is most preferably operably linked to a conventional manually operable handle. If the handle is operated, then the override system preferably prevents the locking formation being moved to the locking position. If the window is closed and the locking formation is in the locking position, then operation of the handle preferably causes the locking formation to be withdrawn to the unlocked position. To this end, the handle may incorporate switch means which are operably connected to the control circuitry of the locking system.

Most preferably, the disabling of the locking system remains operative for a fixed, pre-determined time. Typically, this time may be of the order of 15 seconds. After the expiry of this period, the system returns to normal operation.

The electrical circuitry is preferably battery powered, eg by an alkaline or rechargeable battery. For safety reasons, the electronic circuit is preferably provided with means for monitoring the battery voltage level and disabling the locking system in the event that the voltage falls below a level required for reliable operation. The system may incorporate means, eg an audible tone, to indicate low battery voltage. In the event that the battery voltage falls below a certain threshold value, the operation of the locking means is disabled so that in such circumstances the locking means can never impede escape of personnel through the door or window in an emergency.

Following actuation, the locking formation may remain in the locking position for a pre-determined period and then return to the unlocked position. This pre-determined period could be, say, 20 seconds. Alternatively, or in addition, a remote control unit may be used to return the locking formation to the unlocked position.

The window or door of the present invention may be provided with a visual indicator, eg a flashing LED, to indicate the presence of the automatic security system and to act as a deterrent to any would-be intruder.

In the event that the locking system means is actuated by detection of a vibration or displacement the control circuit may emit an audible alarm, eg by means of a piezoelectric sounder.

Alternatively, the circuit may be connected by suitable means to a conventional burglar alarm.

The locking formations are conveniently projections such as bolts which engage, in the locking position, in recesses in the adjacent face of the frame or panel. The recess is preferably sufficiently large that the locking formation may be received within it even after some displacement of the window or door panel.

The locking means may be housed in the door or window panel, in which case the locking formations engage in the frame.

Alternatively, the locking means may be housed in the frame and the locking formations engage in the door or window panel.

As well as being formed as an integral part of new doors or windows, the locking system of the invention may be added to existing doors or windows, to provide added security.

The invention will now be described in greater detail, by way of illustration only, with reference to the accompanying drawings, in which Figure 1 is a perspective view of a locking device according to the invention, intended for fitting to the edge of a window sash; Figure 2 is a sectional schematic view of the locking device of Figure 1; Figure 3 is a perspective view of a corner of a window sash on which a second form of remotely-actuatable locking device according to the invention is mounted; and Figure 4 is a circuit diagram of control circuitry which may be used to control the embodiments of either Figures 1 and 2 or Figure 3.

Referring first to Figure 1, a locking mechanism for installation on the edge of a hinged window comprises first and second sliding bars 1,2 which, when fitted to the window, lie substantially flush with the edge of the window sash. The adjoining ends of the bars 1,2 are housed in a casing 3. The casing 3 houses an electrical mechanism which acts to slide the bars 1,2 outwardly along the edge of the window sash.

As can be seen from Figure 2, the electrical mechanism comprises a solenoid arrangement 21 which acts on a projection on the underside of the first sliding bar 1. A similar solenoid arrangement (not shown) is provided to act on the second sliding bar 2. The bars 1,2 will move in the direction of the arrows when a positive supply current is applied to the respective solenoid, and in the opposite direction when the electrical supply is reversed.

The outward ends of the sliding bars 1,2 are formed into first and second projections 4,5. When the window is open, the sliding bars 1,2 are retracted and do not protrude beyond the edge of the window sash. The window is locked by bringing the sash into the closed position and operating a conventional handle and locking mechanism.

The locking mechanism shown in Figures 1 and 2 provides additional security in the event that the window is abused, as might happen in an attempted break-in. The solenoids are connected to a movement sensor which detects sudden movement of the window. In the event of such motion being detected, and provided the window is closed, the electrical mechanism then operates to move the sliding bars 1,2 outwards in the directions indicated by the arrows in Figure 1. The first and second projections 4,5 then engage in corresponding recesses provided in the frame, locking the window shut. The electrical circuitry which controls this locking action is described more fully below.

The first and second projections 4,5 remain engaged with frame for a period of 20 seconds, following which the electrical mechanism operates again to retract the projections 4,5 from the recesses. If the abuse of the window is then repeated, the bars 1,2 are once against driven outwards.

Figure 4 shows control circuitry for the locking system. The control circuit is housed in a module which fits within the window sash, and provides the necessary logic to ensure the correct operation of the system, a low battery warning indication and the reversible power source to move the solenoids in each direction. The overall current consumption of the system is low to ensure a reasonable battery life. All the logic is CMOS technology and the drive transistors are low leakage current MOS FETs.

The circuit includes a piezoelectric shock sensor and amplifier (circuit portion A), flashing LED's to provide a visual indication that the system is armed (portion B), and a low battery voltage indicator (portion C) which produces an audible beep in the event that the battery voltage falls below a certain level.

The circuit is battery driven with an alkaline battery. The mechanical handle of the window overrides the electronics to ensure that the window can be opened immediately even if the window has been triggered. A reed switch D is used to detect whether the window is in the open position or not. If the window is in the open position then the electronic bolts cannot operate.

The reed switch is also used to provided the necessary signal to the control circuit to unlock the window when the manual override is required.

The interconnecting wires between the solenoids and the control module must be of sufficiently low resistance that when the large current spike from operating the solenoids occurs the voltage at the solenoids is still adequate. The piezo sensor may be fixed on the epoxy moulded circuit. The sensors could alternatively be mounted directly on the solenoids.

The control circuit shown in Figure 4 may control a number of solenoids, for example up to about four solenoids on one window, particularly in the case of ground floor windows.

In an alternative embodiment, the casing 3 may house only a single electrical mechanism which acts on one or other of the sliding bars 1,2. This enables the same component to be used at, say, the top and bottom edges of a window sash.

Figure 3 shows a second embodiment of the invention in which an auxiliary locking unit 30 is fitted to an existing window sash 31. The locking unit 30 comprises a generally rectangular body 32 which houses a moveable locking pin 33. The body 32 is fixed to the window sash 31 by means of screws 34,35 passing through apertured flanges 36,37 provided on the body 31.

Operation of the locking pin 33 is identical to that of the locking mechanism in the embodiment of Figures 1 and 2, ie in response to a signal from a movement sensor the pin 33 is moved into engagement with a recess in the frame.

The unit 30 can be supplied with a new window, or may be fitted to an existing window to provide added security.

The locking systems of Figures 1 and 2, and Figure 3, provided additional security to a window. The locking formations (bars 1,2 and pin 33) provide a means of locking the window which is independent of the window's normal fixings. In normal use, the locking formations are retracted. In the event of a sudden force being applied to the closed window, the locking formations instantaneously engage the window frame.

Claims

1. A window or door assembly comprising a window or door panel mounted in a frame and moveable from an open position to a closed position, the frame or panel being provided with a locking formation moveable from an unlocked position in which the window or door may be opened, to a locking position in which, when the panel is in the closed position, the window or door is locked, and there being provided locking means operable to move the locking formation from the unlocked position to the locking position in response to an external stimulus.

2. An assembly as claimed in Claim 1, wherein the locking formation is normally in the unlocked position, and the locking means acts to move the locking formation to the locking position only in the event of the external stimulus being detected.

3. An assembly as claimed in Claim 1 or Claim 2, wherein the external stimulus which brings about actuation of the locking means is an impact or sudden movement of the window or door panel.

4. An assembly as claimed in Claim 3, wherein the locking means includes a sensor adapted to detect movement of the window or door panel.

5. An assembly as claimed in Claim 4, wherein the sensor is a piezoceramic sensor or proximity device.

6. An assembly as claimed in Claim 1 or Claim 2, wherein the external stimulus which brings about actuation of the locking means is an ultrasonic, radiofrequency or other signal.

7. An assembly as claimed in Claim 6, wherein the signal is generated by a hand-held remote control unit.

8. An assembly as claimed in any preceding claim, wherein movement of the locking formation from the unlocked to the locking position is brought about by electrical circuitry including a solenoid.

9. An assembly as claimed in Claim 8, wherein the locking formation is a bolt which consists of the moving part of a cylindrical solenoid which moves in and out according to the electrical signal used to drive it.

10. An assembly as claimed in any preceding claim, which is provided with override means to disable the locking means.

11. An assembly as claimed in Claim 10, wherein the override system is operably linked to a conventional manually operable handle.

12. An assembly as claimed in Claim 11, wherein the handle includes switch means which are operably connected to the control circuitry of the locking system.

13. An assembly as claimed in any preceding claim, including battery-powered electrical circuitry.

14. An assembly as claimed in Claim 13, wherein the electrical circuitry includes means for monitoring the battery voltage level and disabling the locking system in the event that the voltage falls below a certain threshold.

15. An assembly as claimed in Claim 14, which incorporates means, eg an audible tone, to indicate low battery voltage.

16. An assembly as claimed in any preceding claim, wherein, following actuation, the locking formation remains in the locking position for a pre-determined period and then returns to the unlocked position.

17. An assembly as claimed in any preceding claim, which is provided with a visual indicator, eg a flashing LED, to indicate the presence of the locking means.

18. An assembly as claimed in any preceding claim, which incorporates means for emitting an audible alarm in the event of actuation of the locking means.

19. An assembly as claimed in any preceding claim, wherein the locking formation is conveniently a projection such as a bolt which engages, in the locking position, in a recess in the adjacent face of the frame or panel.

20. An assembly as claimed in any preceding claim, wherein the locking means is housed in the door or window panel, and the locking formation engages in the frame.

21. A locking system for a window or door, comprising a locking formation moveable from an unlocked position in which the window or door may be opened, to a locking position in which the window or door is locked, means for detecting an external stimulus, and locking means operable to move the locking formation from the unlocked position to the locking position in response to the external stimulus.

22. A locking system as claimed in Claim 21, wherein the external stimulus is an impact or sudden movement of the window or door, and the locking system includes a sensor adapted to detect the impact or sudden movement.

23. A window or door assembly substantially as hereinbefore described.

24. A locking system for a window or door substantially as hereinbefore described.

25. A locking system for a window or door substantially as hereinbefore described with reference to Figures 1 and 2.