Safety device

Abstract

Disclosed herein is a safety device for attachment at an edge of a door leaf. The safety device comprises a pressure monitor and an electromagnetic lock element. The pressure monitor is configured, in response to a force being applied to the safety device, to issue a signal.

Claims

1. A safety device for attachment at an edge of a door leaf, the safety device comprising: a surface plate comprising an opening for receiving a lock element; and a pressure monitor comprising one or more pressure sensors disposed on or in the surface plate, the pressure monitor configured to issue a signal in response to a force detected by the one or more pressure sensors from a ligature being applied to the safety device when the door leaf is in a closed configuration.

2. The safety device of claim 1, wherein the lock element is located within the opening.

3. The safety device of claim 1, wherein the pressure monitor is configured to issue the signal in response to the force being applied to the surface plate.

4. The safety device of claim 1, wherein the surface plate is configured to float relative to the door leaf.

5. The safety device of claim 1, wherein the one or more pressure sensors comprises at least one ribbon switch.

6. The safety device of claim 5, wherein the surface plate bears against the one or more pressure sensors.

7. The safety device of claim 1, further comprising a base plate configured for attachment to the edge of the door leaf.

8. The safety device of claim 7, wherein one or more pressure sensors are attached to the base plate.

9. The safety device of claim 7, wherein the surface plate is coupled to the base plate and is configured to float relative to the base plate.

10. The safety device of claim 1, configured for attachment along at least a portion of the edge of the door leaf.

11. A safety assembly comprising: a door leaf having an edge; and a safety device attached to the edge of the door leaf, the safety device comprising: a surface plate comprising an opening for receiving a lock element; and a pressure monitor comprising one or more pressure sensors disposed on or in the surface plate, the pressure monitor configured to issue a signal in response to a force detected by the one or more pressure sensors from a ligature being applied to the safety device when the door leaf is in a closed configuration.

12. The safety assembly of claim 11, wherein the lock element is located within the opening.

13. The safety assembly of claim 11, wherein the surface plate is configured to float relative to the door leaf.

14. The safety assembly of claim 11, further comprising a base plate configured for attachment to the edge of the door leaf.

15. A door comprising: a door frame; a door leaf pivotally connected to the door frame; and a safety device attached to an edge of the door leaf, the safety device comprising: a surface plate comprising an opening for receiving a lock element; and a pressure monitor comprising one or more pressure sensors disposed on or in the surface plate, the pressure monitor configured to issue a signal in response to a force detected by the one or more pressure sensors from a ligature being applied to the safety device.

16. The door of claim 15, wherein the door leaf is pivotally connected to the door frame by a hinge at a first edge of the door leaf; and wherein the safety device is attached at a second edge of the door leaf, the second edge being opposite from the first edge.

17. The door of claim 15, wherein the lock element is located within the opening.

18. The door of claim 15, wherein the surface plate is configured to float relative to the door leaf.

19. The safety assembly of claim 11, wherein the pressure monitor further comprises: an alert system, wherein the one or more pressure sensors comprises at least one ribbon switch connected to the alert system, wherein the at least one ribbon switch is closed in response to the force from the ligature being applied to the safety device, and wherein the alert system is configured to issue the signal in response to the at least one ribbon switch being closed.

20. The door of claim 15, wherein the lock element is an electromagnetic lock element, wherein the door frame comprises an electromagnet positioned to align with the electromagnetic lock element when the door is in a closed configuration, and wherein the electromagnetic lock element is a ferromagnetic lock plate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Examples of the present disclosure will now be described, by way of example only, with reference to the accompanying figures, in which:

(2) FIG. 1 shows an exploded perspective view of a safety device according to the present disclosure;

(3) FIG. 2 shows an assembled perspective view of the safety device of FIG. 1;

(4) FIG. 3 shows an assembled side view of the safety device of FIG. 1;

(5) FIG. 4 shows an exploded view of the safety device of FIG. 1, as viewed along cross-section A from FIG. 3;

(6) FIG. 5 shows an assembled view of FIG. 4;

(7) FIG. 6 shows an exploded view of the safety device of FIG. 1, as viewed along cross-section B from FIG. 3;

(8) FIG. 7 shows an assembled view of FIG. 6;

(9) FIG. 8 shows an alert system as used in the safety device of FIG. 1; and

(10) FIG. 9 shows a door system including the safety device of FIG. 1.

DETAILED DESCRIPTION

(11) FIG. 1 shows an exploded view of a safety device 100 for attachment to an edge of a door leaf 101. The safety device 100 has an elongate base plate 102 for attachment to the edge of the door leaf 101; two elongate ribbon switches 104a, 104b; an elongate surface plate 106; and a ferromagnetic lock plate 108. End pieces 110, surface plate 106, and base plate 102, enclose the ribbon switches 104 and alert system (not shown in FIG. 1), when the safety device is assembled as shown in FIG. 2. With continued reference to FIG. 1, ferromagnetic lock plate 108 is received within an opening 109 in the surface plate 106.

(12) The safety device 100 has a longitudinal axis L that extends along the length of the safety device 100. The length corresponds to the length of the edge of the door leaf 101 to which the safety device 100 is attached in use. Where elongate components are referred to herein, it is to be understood that those components extend in the longitudinal direction L.

(13) A coupling hole 112 is provided in the base plate 102. When assembled, a coupling means (not shown in FIG. 1) extends through the coupling hole 112 to attach the ferromagnetic lock plate 108 to the base plate 102. The coupling means includes a spring for urging the ferromagnetic lock plate 108 towards the base plate 102, such that the ferromagnetic lock plate sits flush with the surface plate 106 in normal operation of the safety device 100. Coupling means allows floating movement of the ferromagnetic lock plate 108 relative to the base plate 102 (and therefore also relative to the door leaf 101).

(14) Elongate coupling channels 114 are provided along the base plate 102, for attaching the surface plate 106 to the base plate 102. The coupling between the base plate and the surface plate is described in more detail in relation to FIG. 6 below. Coupling channel allows floating movement of the surface plate 106 relative to the base plate 102 (and therefore also relative to the door leaf 101).

(15) FIG. 2 shows an assembled view of the safety device 100 of FIG. 1, mounted to door leaf 101. Only the surface plate 106, ferromagnetic lock plate 108, end pieces 110, and base plate 102 are visible. The other components from FIG. 1 are concealed within the safety device 100. In the depicted example, the ferromagnetic lock plate 108 is located at a centre of the surface plate 106. However, the reader will understand that the ferromagnetic lock plate may be off-centre in other examples.

(16) FIG. 3 shows a side view of the safety device 100 of FIG. 1, mounted to door leaf 100.

(17) Screws (not shown) extend through the base plate 102 of the safety device 100 and into the edge of the door leaf 101, thus securing the safety device 100 to the door leaf 101. However, other attachment methods are envisaged.

(18) The base plate 102 and surface plate 106 are formed by aluminium extrusion. The ferromagnetic lock plate 108 is steel. As the reader will understand, other materials could be usedprovided that the lock plate is ferromagnetic.

(19) FIG. 4 shows an exploded view of the safety device 100, as viewed along cross-section A in FIG. 3. FIG. 5 shows an assembled view of FIG. 4.

(20) As shown in FIGS. 4 and 5, ferromagnetic lock plate 108 is located within opening 109 of surface plate 106, and sits substantially flush with surface plate 106. Furthermore, it includes a first stepped portion 400a on the underside thereof that bears against first ribbon switch 104a, and a second stepped portion 400b on an underside thereof that bears against second ribbon switch 104b. In the depicted example, the ribbon switches are T-shaped, and each step engages a shoulder of a corresponding ribbon switch. Thus, these stepped portions enable the ferromagnetic lock plate 108 to sit flush with the surface plate 106, while still bearing against the ribbon switches 104. Because the ribbon switches 104 are located under the ferromagnetic lock plate 108 (that is, between the ferromagnetic lock plate and the base plate), when an external compressive force of a sufficient magnitude is applied to the ferromagnetic lock plate 108 (for example because of a ligature anchored around the edge of the door leaf 101), at least one of the ribbon switches will be closed and an alert will be issued. This is discussed in more detail in FIG. 8.

(21) FIG. 6 shows an exploded view of the safety device 100, as viewed along cross-section B in FIG. 3. FIG. 7 shows an assembled view of FIG. 6.

(22) As shown in FIGS. 6 and 7, surface plate 106 is received within a recess of the base plate 102 that is defined between peripheral upturned edges 600. Upturned edges eliminate any potential ligature points between the surface plate and the base plate 102; and further restrict the moment of the surface plate in a direction parallel to the plane of the door leaf 101. Furthermore, a bulbus elongate protrusion 602 on the underside of the surface plate 106 engages with the coupling channel 114 of the base plate 102, thereby coupling the surface plate 106 to the base plate 102 while at the same time allowing floating movement of the surface plate 106 relative to the base plate 102, in the direction parallel to the plane of the door leaf. T-shaped ribbon switches 104a, 104b each have an elongate protrusion that bears against corresponding grooves 604a, 604b in the underside of the surface plate 106. Because the ribbon switches 104a, 104b are located under the surface plate 106 (that is, between the surface plate 106 and the base plate 102), when an external compressive force is applied to the surface plate 106 (for example by a ligature anchored around the edge of the door leaf 101), at least one of the ribbon switches will be closed and an alert will be issued. This is discussed in more detail in FIG. 8.

(23) Alert System

(24) FIG. 8 is a schematic illustration of an alert system 800 as used in the safety device of FIGS. 1-7. Collectively, alert system 800 and pressure sensors 104a, 104b make up pressure monitor 801. As shown, alert system 800 is connected to each of the ribbon switches 104a-104b. In particular, alert system comprises a power source 802, connecting block 804, and alert interface 806. Pressure monitor 801 is housed within the safety device 100, although the alert interface of the alert system may be located outside of the safety device. The alert system may be configured to issue an audible alert, a visual alert, or may comprise a transmission means (for example a wireless transmission device) configured to transmit an alert signal to a remote location.

(25) As depicted, each ribbon switch comprises a casing 808 having a hollow cavity 810. Disposed at opposing sides of the hollow cavity are a first electrode 812A and a second electrode 812B. The casing 808 is rubber. Electrodes 812A, 812B are conductors.

(26) In a normal (uncompressed) state, as is shown for ribbon switch 104a, an air gap exists between the first electrode 812A and the second electrode 812B. In this uncompressed state, the switch is openi.e. it does not allow current to flow.

(27) However, when a force F is applied to protrusion 814, as is shown for ribbon switch 104b, the ribbon switch is compressed by the force F. When the force exceeds a threshold amount, it will cause the first and second electrodes 812A, 812B to make contactthus closing the switch such that current can flow. When this happens, the circuit between the battery 802 and the alert interface 806 is completed via the connecting block 804. An alert is thereby issued by the alert interface 806 of the alert system 800. A magnitude of the force required to close any one of the ribbon switches can be selected as required. Typically, the force required to close any one of the ribbon switches may be selected as approximately 68N (i.e. a force that is roughly equivalent the gravitational pull on a mass of 7 kg).

(28) Similarly, if more than one of the ribbon switches are closed, an alert will be issued. Only one of the ribbon switches is required to be closed for an alert to be issued.

(29) Mode of Operation

(30) FIG. 9 shows a door 900 comprising a door frame 902, a door leaf 904 and a safety device 100 as described above and as shown in FIGS. 1-8. Door frame 902 includes an electromagnet 906 positioned to align with ferromagnetic lock plate 108 (not shown in FIG. 9) of the safety device 100. Door leaf 904 is attached to door frame 902 by hinge 908. Door 900 is shown in the closed position.

(31) When electromagnet 906 is in a locked state, it generates a magnetic field that causes a strong attraction between itself and the ferromagnetic lock plate. Accordingly, opening of the door is not possible in the locked state. When electromagnet 906 is in an unlocked state, it does not generate an electromagnetic field that causes an attraction between itself and the ferromagnetic lock plate. Accordingly, opening of the door is possible in the unlocked state.

(32) The electromagnetic lock (which includes the electromagnet 906 and the ferromagnetic lock plate 108) may be a fail-safe electromagnetic lock, meaning that it unlocks the door when not being supplied with power. Or it may be a fail-secure electromagnetic lock, meaning that it locks the door when not being supplied with power.

(33) The ferromagnetic lock plate 108 may project slightly from the safety device when in the locked state. However, it does not project into a socket in the door frame as would be the case for a thrown lock bolt of a mechanical lock. Therefore, even when locked, the electromagnetic lock does not provide a ligature anchor point when in the locked state.

(34) When the electromagnetic lock is in the unlocked state, the door leaf can be opened by rotating it about the hinge 908. Hinge 908 includes a hollow axle extending the full height of the door. Wires for supplying power to the safety device, and for transmitting wired signals to a remote location, can extend through the hollow axle. This protects the wires from accidental or deliberate damage.

(35) When an individual wishes to cause themselves harm, they may try to loop a ligature around the closing edge of the door. In doing so, a force would be applied to the safety device 100 which, once the force exceeds a predetermined threshold, in turn would compress one or both of the ribbon switches, such that an alert is issued by the alert system of the pressure monitor. This alert may be transmitted to a remote location by the wired connection that passes through the hollow axle of the hinge.

(36) It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other implementations will be apparent to those of skill in the art upon reading and understanding the above description. Although the present disclosure has been described with reference to a specific example implementation, it will be recognized that the disclosure is not limited to the implementations described, but can be practiced with modification and alteration insofar as such modification(s) and alteration(s) remain within the scope of the appended claims. Accordingly, the specification and drawings are to be regarded in an illustrative sense rather than a restrictive sense. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled according to the doctrine of equivalents.