WO2024224079A1

WO2024224079A1 - Sensor assembly

Info

Publication number: WO2024224079A1
Application number: PCT/GB2024/051089
Authority: WO
Inventors: Jessica Louise RUMNEY
Original assignee: Assa Abloy Ltd
Current assignee: Assa Abloy Ltd
Priority date: 2023-04-27
Filing date: 2024-04-25
Publication date: 2024-10-31
Anticipated expiration: 2025-10-27
Also published as: GB202306244D0

Abstract

A sensor assembly (2) comprises a base plate (4), a first housing (6) and a second housing (8). The base plate (4) defines a front surface (12) for facing towards a face plate (118) of a door lock (112), and a rear surface (14) for mounting against a door keep (62). The first housing (6) projects from the rear surface (14), and contains bolt sensor circuitry. The second housing (8) projects from the rear surface (14) and defines a battery compartment. The first housing (6) and the second housing (8) project separately from one another so as to define a gap (36) therebetween.

Description

Sensor Assembly

Field of the Invention

The present invention concerns sensor assemblies. More particularly, but not exclusively, the invention concerns sensor assembly which can be fitted to a door keep in a door frame to detect whether the door is locked or not.

Background of the Invention

A lockable door, for instance an external door of a building, often has a lock with a face plate and a bolt. The bolt can be moved (for instance by turning a key) between an unlocked position in which the end of the bolt is approximately flush with the face plate, and a locked position in which the bolt extends beyond the face plate. When the door is closed and locked, the bolt projects into a recess in a keep which is provided on (or integral with) the door frame, thereby preventing the door from being opened until the bolt is retracted to the unlocked position.

In some instances it is desirable for a user to be able to tell if such a door is locked without having to inspect the door (for instance by trying to open it). For example, a user may wish to double-check that they remembered to lock the door after leaving the building without having to return to it. As another example a user inside the building may wish to check that they left the door unlocked (for instance to admit guests), again without having to walk back to the door to check. Equally, it can be desirable for an electronic device such as a smart home hub or an alarm system to be able to detect whether a door is locked or not.

It is known to provide “smart” doors in which a sensor assembly detects whether a door is locked or unlocked, and sends that information to a device such as an alarm system. However, such devices are often heavy and/or bulky, which is undesirable in of itself and can also make it more difficult for the sensor assembly to be accommodated around other components. Further, doing so can mean removing a significant quantity of material all in one place, potentially creating a weak point. Also, such sensor assemblies can sometimes be accidentally fitted upside down, requiring removal and re-fitting at a minimum, and sometimes meaning that components must be replaced (if they have been cut or drilled incorrectly to fit an upside down sensor assembly, for example).

The present invention seeks to mitigate or obviate at least one of the above disadvantages, and/or to provide an improved or alternative sensor assembly, door keep, door keep assembly, or method of assembling a door keep assembly.

Summary of the Invention

According to a first aspect of the present invention there is provided a sensor assembly configured for attachment to a door keep, the sensor assembly comprising: a base plate defining a front surface for facing towards a face plate of a door lock, and a rear surface for mounting against a door keep; a first housing projecting from the rear surface of the base plate, the first housing containing bolt sensor circuitry for detecting the presence of a locking bolt of said door lock; and a second housing projecting from the rear surface of the base plate, the second housing defining a battery compartment, wherein the first housing and the second housing project from the rear surface of the base plate separately from one another so as to define a gap therebetween.

The bolt sensor circuitry being provided in a first housing and the battery compartment being provided in a second housing can reduce the overall weight and/or bulk of the sensor assembly in comparison to an arrangement where a single housing contains both the bolt sensor circuitry and the battery (or batteries). This is somewhat counter-intuitive, as one would generally consider it a better use of space to group all components as close together as possible.

The first and second housings defining a gap can mean that a door keep into which the sensor assembly is attached can be provided with two smaller recesses (one to receive the first housing and one to receive the second housing), rather than a single recess that is large enough to accommodate both housings of the sensor assembly. The lack of need for the keep to have a single large recess can make it easier for the sensor assembly to be retrofitted to an existing keep (where there may be limited space available around other components), and/or can mean that an existing door keep can be redesigned for use with the sensor assembly with only relatively minor changes being needed. Instead or as well, it can allow the keep to be stronger and/or more rigid.

Instead or as well, the first and second housings defining a gap therebetween can be beneficial in allowing more sensor assemblies to be tessellated into the same space when packing in bulk, with part of one sensor assembly (or its packaging) being received in the gap of another sensor assembly. Furthermore, with the first and second housings projecting separately from one another, they can be configured (for instance shaped, sized or angled) to make it more difficult for a person to fit the sensor assembly upside down in a keep.

The base plate may be planar, for instance generally rectangular, oval or superelliptical. However, in other embodiments the base plate may contain one or more discrete bends or may be generally curved.

The first housing and the second housing may each have any suitable shape, for instance cuboidal, hemispherical, ovoid or prismatic.

The first housing may project along a first axis, which may be substantially normal to the rear surface of the base plate. Instead or as well, the second housing may project along a second axis, which may be substantially normal to the rear surface of the base plate.

The bolt sensor circuitry may comprise an inductive sensor for sensing the presence of a metal locking bolt.

The use of an inductive sensor may be beneficial in that the sensing functionality can be beneficially reliable in adverse conditions such as wet weather, can place relatively fewer constraints on the design and materials of the bolt, and/or can have a long service life (since it can be non-contact and contain no moving parts, and therefore less vulnerable to wear).

Instead or as well, the bolt sensor circuitry may comprise one or more of a contact switch, a Hall effect sensor, a magnetic reed switch, an RFID sensor or any other suitable type of sensor.

The sensor assembly may further comprise door sensor circuitry for detecting the presence of a door that comprises said door lock.

This can be advantageous in that the sensor assembly can detect if a door is closed or not, as well as whether it is locked or not. This, in turn, can be advantageous in providing more information to a user. Instead or as well, it may be useful for troubleshooting. For instance, if the door sensor circuitry reads that the door is absent (i.e. open) but the bolt sensor circuitry is reading that the bolt is present, this may be indicative of a fault.

The door sensor circuitry may be provided in the second housing.

The door sensor circuitry and the bolt sensor circuitry may therefore be spaced apart from one another, which may be beneficial in reducing the possibility of interference therebetween. Instead or as well, the door sensor circuitry being provided in the second housing may allow for a particularly straightforward electrical connection between the door sensor circuitry and a battery in the battery compartment.

Alternatively, the door sensor circuitry (where present) may be provided in the first housing (for example on a circuit board which is common to the bolt sensor circuitry), in a third housing, embedded in the base plate, or in any other suitable location.

The door sensor circuitry may comprise a Hall effect sensor for detecting the presence of a magnet provided on said door.

This may be beneficial in that it is relatively unlikely for a magnet other than the one provided in the door to pass in close proximity to the door sensor circuitry (which could produce a “false positive” reading). In comparison, in an arrangement where the door sensor circuitry detected any metal object then a false positive may be produced from keys, buttons, zips or the like as a person walks through the door, or in an arrangement where the door sensor circuitry was operated by physical contact then a false positive may be produced as a result of someone brushing past the sensor assembly.

Instead or as well, the door sensor circuitry may comprise one or more of a pressure switch, an induction sensor, a magnetic reed switch, an RFID sensor or any other suitable type of sensor.

The first housing may project from the base plate along a first axis, the second housing may project from the base plate along a second axis, and the first and second axes may be substantially parallel to one another.

This may enable advantageously straightforward installation of the sensor assembly to a door keep - an operator can simply align the two housings with their respective apertures, then move the sensor assembly in a direction in line with the first and second axes until the rear surface of the base plate contacts the door keep. Alternatively, the first and second axes may not be parallel (whereupon installation may involve twisting movement and/or a degree of elastic deformation of the sensor assembly or the door keep.

One of the first and second housings may project further from the base plate than the other.

This may improve the ease with which the sensor assembly can be installed on a door keep, as an operator can concentrate on aligning the longer housing with its aperture first, and then once the distal end of that housing is inserted into its aperture the operator can concentrate on inserting the shorter housing into its aperture, rather than needing to align both housings with their respective apertures simultaneously.

It may be the second housing that projects further from the base plate than the first housing, and the second housing may be substantially cylindrical.

This may further improve ease of installation. The cylindrical shape of the second housing may be inserted into a complementary recess so as to constrain the sensor assembly for rotation only about the second axis, which may make it easier to align the first housing with its recess than if the sensor assembly had more degrees of freedom.

The base plate may define an opening for receipt of said locking bolt therethrough, and the first housing may be positioned at an edge of said opening.

This can place the bolt sensor circuitry advantageously close to the bolt when the door is locked, which may improve the reliability of the readings produced by the circuitry.

The opening may be an aperture, for instance an aperture which is surrounded by material around its entire circumference.

This may allow the base plate, and thus the sensor assembly as a whole, to be advantageously rigid and/or strong.

The opening may be open-sided.

This may reduce the weight of the sensor assembly, and/or reduce production costs by reducing the amount of material required.

Optionally: the base plate extends along a length direction, the first housing and second housing being spaced apart from one another along the length direction; the base plate extends across a width direction which is substantially perpendicular to the length direction; and the opening is open-sided in the width direction.

This may make the sensor assembly particularly well suited to use with a door which opens and closes in a particular direction. For example, the open side may allow the door to close with the bolt slightly proud of the door (whereas with an aperture, the bolt would be more likely to collide with the base plate), and/or may allow the bolt to be extended and retracted with the door slightly out of true (e.g. slightly ajar).

The first housing may be positioned such that a surface thereof intersects an edge of the opening. As an alternative, said surface may be positioned slightly recessed behind said edge of the opening.

In other embodiments where the base plate defines such an opening, the first housing may be positioned relatively far from that opening (but the bolt sensor circuitry may be sufficiently powerful for the bolt to nonetheless be detected).

The first housing may define a surface which faces generally towards the opening, and the sensor assembly may further comprise a reset button positioned on that surface.

This location may allow the reset button to be relatively easily accessed when needed, yet relatively unlikely to be operated by accident (for instance by someone brushing past the sensor assembly).

A surface may be considered to face generally towards the aperture if it faces towards an axis that passes through the aperture and is normal to the front surface of the base plate, for example.

Alternatively, the reset button (where present) may be positioned in any other suitable location. In such embodiments other steps may be taken to prevent accidental operation (for instance the reset button may need to be pressed and held, or pressed by inserting a narrow tool into a hole within which the button is provided). Instead or as well, ease of access of the reset button may be sacrificed in the name of avoiding accidental operation. For instance, the reset button may be positioned such that it cannot be operated while the sensor assembly is installed on a door keep.

The sensor assembly may further comprise an electrical conductor extending between the first and second housings, the electrical conductor being encased in potting compound.

The electrical conductor may be relatively vulnerable to damage (before, during and/or after installation), and/or may be particularly vulnerable to water ingress. Encasing it in potting compound may therefore make the conductor, and by extension the sensor assembly as a whole, more robust.

Any suitable potting compound may be used, for instance epoxy, polyurethane, silicone or polyamide.

In other embodiments with an electrical conductor extending between the housings, the conductor may be provided in a protective groove or housing instead of being encased in potting compound, or other steps may be taken to protect it (for instance it may be covered in one or more layers of heat-shrink tubing).

The sensor assembly may further comprise wireless communications circuitry.

This can allow the sensor assembly to communicate wirelessly with a smart home hub, a computer, a smartphone or the like. This can make information gathered by the sensor assembly advantageously easily accessible to an end user.

As an alternative, the sensor assembly may be arranged for wired communication (for instance with a computer or a separate wireless transmitter), or the sensor assembly may be a self-contained unit which provides information to the end user using a screen, a speaker and/or one or more lights.

The first housing and the second housing may have different cross-sectional shapes to one another.

For example, the housings can have a different number of sides and/or a different aspect ratio in cross section, meaning that each housing cannot fit (or is obviously not intended to fit) in a recess shaped to accommodate the other. This can reduce the risk of an operator fitting the sensor assembly to a door keep upside down.

Alternatively, the housings may have the same cross sectional shape as one another, in which case other means may be provided to prevent installation upside down (for instance the base plate may be shaped or marked to indicate which way up it should go).

According to a second aspect of the present invention there is provided a door keep configured for engagement with a sensor assembly according to the first aspect of the invention, the door keep comprising: a mounting surface configured for engagement with the rear surface of the sensor assembly; a first recess extending through the mounting surface, the first recess being configured to receive the first housing of the sensor assembly and said locking bolt of said door lock; and a second recess extending through the mounting surface, the second recess being configured to receive the second housing of the sensor assembly.

As described in relation to the first aspect of the invention, the door keep having a pair of recesses may allow it to be stronger and/or more rigid than one in which a single large recess accommodates both the housings of the sensor assembly.

The mounting surface may be generally planar. As an alternative, the mounting surface may be arcuate (for instance to engage an arcuate base plate) or undulating (for instance to engage a complementarily-undulating base plate, or to engage a flat base plate with the troughs of the undulating mounting surface providing space for adhesive of the like).

Part of the first recess may have a complementary cross sectional shape to that of the first housing. Indeed, the first recess may be shaped to receive the first housing and bolt with minimal gap. This may provide an advantageously solid interface between door keep, sensor assembly and door lock (in contrast to an arrangement with a larger gap, where the door may “rattle” when pushed or pulled by wind or the like while locked).

Instead or as well, the second recess may have a complementary cross sectional shape to that of the second housing. Further, the second recess may be shaped to receive the second housing with minimal gap therebetween. Indeed, the second recess may be shaped to receive the second housing with a snug fit or an interference fit.

The first recess and the second recess may extend separately from one another so as to define a portion of material therebetween, the portion of material being shaped for receipt within the gap defined by the sensor assembly.

This can allow the door keep to “mesh” with a sensor assembly according to the first aspect of the invention to an advantageous extent, thereby providing a tighter and/or stronger connection therebetween.

The portion of material may be substantially uninterrupted. As an alternative, the portion of material may comprise multiple members and/or may have one or more holes or channels provided therein.

As an alternative to the first and second recesses extending separately from one another, the first and second recesses may be linked together, for example forming a figure-8 shape. It is to be understood, however, that the first and second recesses are necessarily distinguishable from one another. Reference to first and second recesses is not intended to apply merely to arbitrarily-selected portions of a single recess.

According to a third aspect of the present invention there is provided a door keep assembly comprising a sensor assembly according to the first aspect of the invention, and a door keep according to the second aspect of the invention.

A door keep assembly according to the third aspect of the invention may be lighter overall as discussed in respect of the first aspect of the invention, and/or may be stronger or more rigid as discussed in relation to the first and second aspects of the invention. Instead or as well, the door keep assembly may be advantageously easy to assemble with the sensor assembly the right way up, as discussed in respect of the first aspect of the invention.

According to a fourth aspect of the present invention there is provided a door keep assembly comprising a door keep according to the second aspect of the invention and a dummy sensor assembly which does not comprise bolt sensor circuitry.

A door keep assembly according to the fourth aspect of the invention may be able to be sold separately to the sensor assembly of the first aspect of the invention, without the aesthetics or function of the door keep assembly being negatively impacted by the absence of the sensor assembly. For instance the dummy sensor assembly may protect the mounting surface from damage such as accidental knocks, and/or may fill a gap which would otherwise be present at the mounting surface of the door keep, avoiding the risk of air or water leaking through that gap. Being able to sell the door keep assembly separately to the sensor assembly can allow a manufacturer to sell both a “dumb” door keep assembly and a “smart” door keep assembly both using the same door keep, which can reduce tooling and distribution costs.

Furthermore, a door keep assembly according to the fourth aspect of the invention may also be advantageously easily retrofitted with (or redesigned for) a sensor assembly according to the first aspect of the invention, if desired.

Optionally, the dummy sensor assembly includes neither bolt sensor circuitry nor door sensor circuitry. Indeed, the dummy sensor assembly may be devoid of electronic components. In other embodiments, however, the dummy sensor assembly may comprise one or more pieces of electronic circuitry (e.g. door sensor circuitry and/or electrical contacts for an alarm system).

The dummy sensor assembly may comprise: a base plate defining a front surface for facing towards said face plate of said door lock, and a rear surface for engagement with the mounting surface of the door keep; and a second dummy housing projecting from the rear surface of the base plate and shaped for receipt within the second recess of the door keep.

The dummy sensor assembly may therefore have the same general layout as a sensor assembly according to the first aspect of the invention. This may improve the extent to which the dummy sensor assembly can avoid the aesthetics or function of the door keep assembly being negatively impacted by the absence of the sensor assembly as discussed above. Instead or as well, it may allow the dummy sensor assembly to act as an effective demonstrator, showing how and where a sensor assembly according to the first aspect of the invention can be fitted to the door keep.

The second dummy housing may be the only component to project significantly from the rear surface of the base plate. For instance, the dummy sensor assembly may lack a first dummy housing (whereupon the rear surface may have a flat or blanked-off region at the location at which, in a sensor assembly according to the first aspect of the invention, the first housing would project).

This can make the dummy sensor assembly suited for use on a wider range of door keeps. For instance, in some embodiments there may be different versions of a sensor assembly depending on the direction in which a door opens and closes, but a single dummy sensor assembly may be suitable for use on door keeps regardless of the direction in which the door opens.

Reference to the second dummy housing being the only component to project significantly from the rear surface of the base plate is not intended to preclude the possibility of components projecting from the rear surface by a very minor amount (for instance texturing on the rear surface to improve adherence to the mounting surface of a door keep). The second dummy housing may be considered to be the only component to project significantly from the rear surface of the base plate if no other components project from the rear surface by more than 20%, or no more than 10% or no more than 5%, of the distance over which the second dummy housing projects.

Optionally: the dummy sensor assembly further comprises a first dummy housing projecting from the rear surface of the base plate and shaped for receipt within the first recess of the door keep along with said locking bolt; and the first dummy housing and the second dummy housing project from the rear surface of the base plate separately from one another so as to define a gap therebetween.

This may increase the extent to which the dummy sensor assembly has the same general layout as a sensor assembly according to the first aspect of the invention, which may increase one or more of the advantages discussed above. Instead or as well, it may increase the extent to which the same tooling can be used to produce both sensor assemblies and dummy sensor assemblies.

Optionally, the dummy sensor assembly does not have an opening for receipt of a locking bolt therethrough. In some such arrangements, the dummy sensor assembly may have a base plate configured whereby with the second dummy housing received in the second recess of the door keep, the base plate substantially cannot overlap the first recess of the door keep.

According to a fifth aspect of the present invention there is provided a method of assembling a door keep assembly according to the third aspect of the invention, the method comprising: providing the door keep and the sensor assembly separately from one another; inserting the first housing of the sensor assembly into the first aperture of the door keep and inserting the second housing of the sensor assembly into the second aperture of the door keep; and securing the rear surface of the base plate of the sensor assembly against the mounting surface of the door keep.

The method of the fifth aspect of the invention can be used to provide a door keep assembly with one or more of the advantages discussed above in respect of the third aspect of the invention.

The step of providing the door keep and the sensor assembly separately to one another may comprises providing a door keep assembly according to the fourth aspect of the invention and then removing the dummy sensor assembly from the door keep.

The door keep being provided in this way can enable the door keep to be already in situ and in use (and thus potentially providing one or more of the advantages discussed in relation to the fourth aspect of the invention) before installation of the sensor assembly. Instead or as well, the dummy sensor assembly may protect the mounting surface of the door keep from knocks and the like before the sensor assembly is installed, thereby providing an improved level of fit and finish. It will of course be appreciated that features described in relation to one aspect of the present invention may be incorporated into other aspects of the present invention. Additionally, the method of the invention may incorporate any of the features described with reference to the apparatus of the invention and vice versa.

Description of the Drawings

Embodiments of the present invention will now be described by way of example only with reference to the accompanying schematic drawings of which:

Figure l is a front perspective view of a sensor assembly according to a first embodiment of the invention;

Figure 2 is a rear perspective view of the sensor assembly of Figure 1;

Figure 3 is a side view of the sensor assembly of Figures 1 and 2;

Figure 4 is an exploded view of the sensor assembly of Figures 1 to 3;

Figure 5 is an exploded view of a door keep assembly which comprises the sensor assembly of Figures 1 to 4;

Figure 6 is a front perspective view of a dummy sensor assembly for use with a door keep of the door keep assembly shown in Figure 5;

Figure 7 is a side view of the door keep assembly of Figure 5, adjacent to a door lock;

Figure 8 is a cross-sectional side view of the door keep assembly and the door lock, engaged with one another;

Figure 9 is a front perspective view of a dummy sensor assembly according to a second embodiment of the invention;

Figure 10 is a rear perspective view of the dummy sensor assembly of Figure 9;

Figure 11 is a front perspective view of a sensor assembly according to a third embodiment of the invention;

Figure 12 is a rear perspective view of the sensor assembly of Figure 11;

Figure 13 is an enlargement of part of Figure 11;

Figure 14 is a front perspective view of a sensor assembly according to a fourth embodiment of the invention;

Figure 15 is a rear perspective view of the sensor assembly of Figure 14; Figure 16 is a front perspective view of a dummy sensor assembly of a fifth embodiment of the invention; and

Figure 17 is a rear perspective view of the dummy sensor assembly of Figure 16.

Detailed Description

Figures 1 to 4 show a sensor assembly 2 according to a first embodiment of the invention. The sensor assembly 2 has a base plate 4, a first housing 6 and a second housing 8.

The base plate 4 extends along a length direction 9, and extends across a width direction 11 which is perpendicular to the length direction. The base plate 4 has a front surface 12 and a rear surface 14. The front surface 12 is configured to face towards a face plate of a door lock (not shown) when a door is shut, and the rear surface is configured to mount onto a door keep (not shown), as discussed later. In this case the base plate 4 is planar, and superelliptical in shape (i.e. “lozengeshaped”). It has markings 16 on the front surface 12 and an elongate groove 18 on its rear surface. The base plate 4 also defines an opening 20 in the form of an aperture which is surrounded by material around its circumference, through which a bolt of a door lock (not shown) can be received, and a screw hole 21.

The first housing 6 projects from the rear surface 14 of the base plate 4, along a first axis 22. In this case the first axis 22 is normal to rear surface, and indeed normal to the plane of the base plate 4 as a whole. The first housing 6 is rectangular in cross sectional shape, more specifically a long and narrow elongate rectangle in this example. It is bonded to the rear surface 14 of the base plate 4 using adhesive but may, in other embodiments, be integrally formed with the base plate 4. In this embodiment, the first housing 6 is positioned at an edge 24 of the aperture 20. Indeed, in this embodiment a surface 26 of the first housing 6 is positioned to intersect that edge 24 of the aperture 20.

The first housing 6 also has a reset button 28. In this embodiment the reset button 28 is positioned on a surface 26 of the first housing 6 which faces generally towards the aperture 20, which in this particular embodiment is the same surface 26 that intersects the edge 24 of the aperture 20. Accordingly, the reset button 28 also faces generally towards the aperture 20, for easy access by a user if needed.

Contained within the first housing 6 is bolt sensor circuitry 30, which in this case is provided on a PCB. The bolt sensor circuitry 30 is arranged to detect the presence of locking bolt or a door lock (not shown). The circuitry 30 has an inductive sensor 32 for detecting when a metal bolt is in close proximity, as discussed in more detail later.

The sensor assembly 2 also has wireless communication circuitry 33 by which the sensor assembly 2 can communicate wirelessly with a smart home hub, a computer, a smartphone or the like. In this particular embodiment the wireless communication circuitry 33 is provided on the same PCB as the bolt sensor circuitry 30.

Like the first housing 6, the second housing 8 projects from the rear surface 14 of the base plate 4. The second housing 8 projects along a second axis 34, which in this case is also normal to the rear surface 14 (and thus normal to the plane of the base plate 4). The first and second axes 22, 34 are therefore parallel to one another. Although the first and second housings 6, 8 project from the same surface (and in this case project in parallel directions), they project separately from one another and define a gap 36 between them. In particular, they are spaced apart along the length direction 9 of the base plate 4.

It is noteworthy that the second housing 8 projects further from the base plate 4 than the first housing 6, as shown most clearly in Figure 3. It is also noteworthy that whereas the first housing is cuboidal, and is therefore rectangular in cross section, the second housing 8 is cylindrical, meaning that it is circular in cross-section.

The second housing 8 defines a battery compartment. The second housing 8 comprises an outer receptacle 38, which in this case is integrally moulded with the base plate 4, and a battery holder 40 which can hold one or more batteries 42 (three, in this specific case). The battery holder 40 can be inserted into the outer receptacle 38 and screwed into place, thereby connecting the batteries to the circuitry of the sensor assembly 2. The battery holder 40 has knurling 44 on its end, to improve the ability of a user to grip it to screw or unscrew it.

As well as forming the battery compartment, the second housing contains door sensor circuitry 46 provided on a small round PCB. The door sensor circuitry 46 includes a Hall effect sensor 48 which is configured to detect a magnet provided on a door (not shown). In this specific embodiment the bolt sensor circuitry 32 in the first housing 6 is connected to the batteries 42 in the second housing 8 via the door sensor circuitry 46.

The bolt sensor circuitry 32 is connected to the door sensor circuitry 46, and thus to the batteries 42, by an elongate electrical conductor in the form of a ribbon cable 50. The ribbon cable runs between the bolt sensor circuitry 32 and the door sensor circuitry 46 through the groove 18 in the rear surface 14 of the base plate 4. The ribbon cable 50 is encased in an epoxy potting compound (not shown) so as to secure it in the groove 18 and protect it from knocks and/or water ingress.

Figure 5 shows an exploded view of a door keep assembly 60 according to this embodiment. The door keep assembly 60 comprises the sensor assembly 2, a door keep 62, and a mounting screw 64 by which the sensor assembly 2 can be secured to the door keep 62.

The door keep 62 has a mounting surface 66 configured to engage with the rear surface 14 of the base plate 4 of the sensor assembly. The mounting surface 66 is of complementary shape to the rear surface 14, both surfaces being planar in this case. Extending through the mounting surface 66 is a first recess 68 which is configured to receive the first housing 6 of the sensor assembly and also the bolt of a door lock (not shown). Also extending through the mounting surface 66 is a second recess 70 which is configured to receive the second housing 8 of the sensor assembly 2. The door keep 62 defines a portion 72 of material between the first and second recesses 68, 70. In this specific case the portion 72 of material has a small aperture 74 the purpose of which is not material to the present invention.

The second recess 70 of the door keep 62 is of complementary cross sectional shape to the second housing 8 of the sensor assembly. More particularly, the second recess 70 is also circular in cross section and has an inner diameter only slightly larger than the outer diameter of the second housing 8. The second recess 70 is therefore shaped to receive the second housing 8 with minimal gap therebetween. The first recess 68 is of complementary cross sectional shape to that of the first housing 6, while leaving sufficient space for the bolt of a door lock (not shown) to be received as well. The first recess 68 is shaped so that there is minimal gap when the bolt (and the first hosing 6) are received therein, reducing the amount of “rattle” which the locked door exhibits. The door keep 62 also has a latch recess 80 which is positioned above the mounting surface 66 (from the perspective of Figure 5) and stands slightly proud thereof. The latch recess 80 is configured to receive a latch of a door lock. The door keep 62 of this particular embodiment is a composite keep, having other components 82 positioned behind the latch recess 80 and held in place with screws 84. The purpose of these components is not material to the present invention so will not be described.

The door keep 62 of this embodiment also has a threaded hole 86 for engagement with the mounting screw 64, and plain holes 88 for fasteners by which the door keep 62 (and thus the whole door keep assembly 60) can be mounted to a door frame (not shown).

To assemble the door keep assembly, the sensor assembly 2 and door keep 62 are provided separately from one another. The first and second housings 6, 8 of the sensor assembly 2 are then inserted into the first and second recesses 68, 70 respectively. The first and second housings 6, 8 having different cross sectional shapes means that it is clear to an operator which housing 6, 8 should be inserted into which recess 68, 70, so it is unlikely that an operator would accidentally fit the sensor assembly 2 to the door keep 62 upside down. Indeed, the first housing 6 is considerably longer than the diameter of the second housing 8, so it is impossible to insert the first housing 6 into the second recess 70.

In this embodiment, the second housing 8 is inserted a short way into the second recess 70 before the first housing 6 reaches the first recess 68. The cylindrical housing 8 being received in the circular recess 70 constrains the sensor assembly 2 such that it can only be rotated about the second axis. The user can then simply rotate the sensor assembly until the first housing 6 is aligned with the first recess 68, whereupon the first housing 6 can be inserted into the first recess 68. As the housings 6, 8 of the sensor assembly 2 are inserted into the recesses 68, 70 of the door keep 62, the portion 72 of material between the recesses 68, 70 is inserted into the gap 36 between the housings 6, 8.

The housings 6, 8 continue to be inserted into their respective recesses 68, 70 until the rear surface 14 of the base plate 4 contacts the mounting surface 66 of the keep 62. At this point, the rear surface 14 of the base plate 4 can be secured against the mounting surface 66 of the keep 62 by inserting the mounting screw 64 through the screw hole 21 of the sensor assembly 2 and tightening it into the threaded hole 86 of the door keep 62.

In this particular embodiment the door keep 62 is supplied as a door keep assembly that has a dummy sensor assembly, which does not include bolt sensor circuitry, fitted to it in the same location as will be occupied by the sensor assembly 2. This will now be described with reference to Figure 6, which shows the dummy sensor assembly 90 in isolation, in conjunction with Figures 1 to 5.

The dummy sensor assembly 90 has a base plate 92, a first dummy housing 94 and a second dummy housing 96. Like the base plate 4 of the sensor assembly 2, the base plate 92 of the dummy sensor assembly 90 has a front surface 98 for facing towards a face plate of a door (not shown) and a rear surface 100 for engaging the mounting surface 66 of the door keep 62.

In corresponding fashion to the first housing 6 of the sensor assembly 2, the first dummy housing 94 of the dummy sensor assembly 90 projects from the rear surface 100 of the base plate 92 and is shaped for receipt within the first recess 68 of the door keep 62 along with the locking bolt (not shown). Similarly, as with the second housing 8 of the sensor assembly 2, the second dummy housing 96 projects from the rear surface 100 of the base plate 92 and is shaped for receipt within the second recess 70 of the door keep 62. Further, like the first and second housings 6, 8 of the sensor assembly 2, the first and second dummy housings 94, 96 of the dummy sensor assembly 90 project separately from one another so as to define a gap 102 therebetween.

Indeed, the dummy sensor assembly 90 is almost identical in shape to that of the sensor assembly 2, and interacts with the door keep 62 in the same way. The dummy sensor assembly 90 does not include bolt sensor circuitry or door sensor circuitry, so has no need for batteries, a ribbon cable or a reset button, but aside from this the only difference between the sensor assembly 2 and the dummy sensor assembly 90 is the reduced number of markings 16. Accordingly, further explanation of the physical features of the dummy sensor assembly 90, and its interaction with the door keep 62, can be ascertained with reference to the explanation provided in respect of the sensor assembly 2.

Since the door keep 62 is provided as a door keep assembly which includes the dummy sensor assembly 90, to perform the step of providing the door keep 62 and the sensor assembly 2 the dummy sensor assembly 90 must be removed from the door keep 62. This can be done simply by loosening a mounting screw, pulling the base plate 92 off the mounting surface 66 and withdrawing the first and second dummy housings 94, 96 from their respective recesses 68, 70. The sensor assembly 2 can then be installed in place of the dummy sensor assembly 90.

Operation of the door keep assembly 60 comprising the sensor assembly 2 will now be described with reference to Figures 7 and 8, in conjunction with Figures 1 to 6. Figures 7 and 8 show the door keep assembly 60 installed on a door frame 110 (part of which is visible), opposite a door lock 112 mounted on a door 114 (part of which is visible). Figure 7 shows the door keep assembly 60 and lock 112 spaced apart from one another for the sake of clarity, while Figure 8 shows them engaged with one another. Both figures show the lock 112 in its locked configuration, with its bolt 116 projecting beyond its face plate 118.

As well as the bolt 116 and face plate 118, the door lock 112 has a magnet 120 and a latch 122. Many other features of the lock 112 are also shown, but these are not material to the present invention so will not be described.

When the door 114 is open, its magnet 120 is spaced from the Hall effect sensor 48 of the door sensor circuitry 46 of the sensor assembly 2, and the bolt 116 is distant from the inductive sensor 32 of the bolt sensor circuitry 30. The sensor assembly 2 therefore reports to a user that the door is open and unlocked, using the wireless communication circuitry 33.

When the door is closed but unlocked, the latch 122 of the lock 112 is received in the latch recess 80. This acts to hold the door closed, holding the magnet 120 in position proximate to the Hall effect sensor 48 of the door sensor circuitry 46, which detects its presence. Since the door is unlocked, the bolt 116 is flush with the face plate 118. So positioned, the bolt 116 is too distant from the inductive sensor 32 to be detected. Accordingly, the sensor assembly 2 reports that the door is closed and unlocked.

When the door is locked (when closed), the bolt 116 projects from the face plate 118, through the aperture 20 in the base plate 4 of the sensor assembly 2 and into the first recess 68 (alongside the first housing 6). In this position, the bolt 116 is positioned close enough to the inductive sensor 32 to be detected. The inductive sensor 32 generates a magnetic field which induces an electric current in the bolt 116, and that current then generates a magnetic field which is detected by the sensor 32. The sensor assembly 2 therefore reports that the door is closed and locked. It is noteworthy that in this embodiment, the aperture 20 of the sensor assembly is not positioned evenly between the two edges of the base plate 4. Rather, when viewed from the front the aperture 20 is positioned closer to the right edge of the base plate 4 than the left edge. This positions the aperture 20 in the optimal location for the first recess 68 of this specific door keep 62. However, this may mean that the sensor assembly 2 is better suited to doors that open in one direction than doors which open in the other direction. In this case, the sensor assembly 2 is optimised for use with doors that open clockwise when viewed from above. A slightly different sensor assembly would be provided for use with a door which opened anticlockwise when viewed from above. Such a sensor assembly would effectively be a mirror image of the sensor assembly 2 described above - when viewed from the front the aperture would be nearer the left edge of the base plate, and the first housing would be positioned at the right hand edge of the aperture. The same applies in respect of the dummy sensor assembly 90.

That being said, in other embodiments the sensor assembly may be designed so as to be optimised for use with a door which opens in either direction. For example, the aperture could be positioned centrally between the sides of the face plate. In such an example the first housing may be provided in the same position as that of the first embodiment, or could be positioned at a different location (for instance at the top edge or at the bottom edge of the aperture rather than at a side edge). Again, the same may apply in respect of a dummy sensor assembly as well. Furthermore, in some embodiments the configuration of the sensor assembly may vary depending on which direction the door opens, but there may be a common dummy sensor assembly which can be used in either case.

A second embodiment of the invention will now be described, with reference to Figures 9 and 10, in combination with Figures 1 to 8. In Figures 9 and 10, common reference numbers denote common features. The second embodiment is very similar to the first embodiment, therefore only the differences will be described in detail.

The second embodiment differs from the first embodiment only in terms of the dummy sensor assembly 90. Whereas the dummy sensor assembly 90 of the first embodiment has a first dummy housing 94 and a second dummy housing 96, the dummy sensor assembly 90 of the second embodiment only has a second dummy housing 96 (and thus there is no gap 102). Indeed, the second dummy housing 96 is the only component which projects from the rear surface 100 of the base plate 92 at all. The rear surface 100 of the base plate 92 of this embodiment has a blanked-off region 124 at the location from which the first housing 6 projects in the case of the sensor assembly 2 (i.e. the location from which the first dummy housing 94 projects in the case of the dummy sensor assembly 90 of the first embodiment).

The dummy sensor assembly 90 of this embodiment also differs from that of the first embodiment in that it is a single polymeric moulding, rather than being a multi-piece assembly (the name “dummy sensor assembly" being used because it is a dummy version of the sensor assembly, rather than because the dummy is itself an assembly). Further, whilst the dummy sensor assembly 90 of the first embodiment had knurling 44 to match that of the sensor assembly 2, this is omitted from the dummy sensor assembly 90 of this embodiment. For the sake of completeness, the dummy sensor assembly 90 of the second embodiment also differs from that of the first embodiment in that it has the same markings 16 that are present on the sensor assembly 2.

A sensor assembly 2 according to a third embodiment of the invention is shown in Figures 11 to 13, which will now be referred to along with Figures 1 to 10. The third embodiment is similar to the first embodiment, therefore only the differences will be described.

The sensor assembly 2 of the third embodiment differs from that of the first embodiment in that its opening 20 is open-sided. More particularly, the opening is open-sided in the width direction 11, generally to the left from the perspective of Figure 11. This makes the sensor assembly 2 of this embodiment more suited to doors which open anticlockwise when viewed from above. The bolt of such a door would pass across the open side of the opening 20, providing the bolt with more clearance - the door may be opened and closed with the bolt standing slightly proud, or the bolt may be extended or retracted with the door slightly ajar, with reduced risk of part of the base plate 4 obstructing the bolt.

The location of the first housing 6 in the sensor assembly 2 is also different to that of the first embodiment. In the present embodiment the first housing 6 is positioned towards the right of the base plate 4 when viewed from the front, whereas in the first embodiment the first housing was positioned towards the left. For the sake of completeness the sensor assembly 2 also has two screw holes 21, rather than a single screw hole as per previous embodiments. The sensor assembly 2 of the third embodiment also differs from that first embodiment in that the battery holder 40 attaches to the outer receptacle 38 through a bayonet mechanism, rather than screwing into place. As shown most clearly in Figure 13, the outer receptacle 38 has a set of L-shaped slots 130, each of which receives an outwardly-projecting pin 132 of the battery holder 40. The battery holder 40 can thus be attached to the outer receptacle 38 by pushing it in then twisting clockwise, and removed by twisting it anticlockwise then pulling it out, in a manner akin to attaching/removing a bayonet fit light bulb.

Finally, the sensor assembly 2 of this embodiment does not have a reset button. Instead, the bolt sensor circuitry is positioned behind a cover plate 134 attached with a pair of screws 136. If it is necessary to reset the sensor assembly 2 this can be achieved by removing it from a door keep, then removing and replacing the battery holder 40 to temporarily cut power and thus implement a start-up routine.

A sensor assembly 2 according to a fourth embodiment of the invention is shown in Figures 14 and 15, which will now be referred to along with Figures 1 to 13. The fourth embodiment is similar to the third embodiment, therefore only the differences will be described.

The sensor assembly 2 of this embodiment is, generally speaking, a mirror image of that of the third embodiment - the opening 20 is open-sided towards the right from the perspective of Figure 14, and the first housing 6 is positioned towards the left. The sensor assembly 2 of this embodiment is therefore more suited to doors which open clockwise when viewed from above, in similar manner to the sensor assembly of the first embodiment.

The sensor assembly 2 of this embodiment also differs from that of the third embodiment in that it has a reset button 28 in similar fashion to the sensor assembly of the first embodiment.

A fifth embodiment of the invention will now be described with reference to Figures 16 and 17, in combination with Figures 1 to 15. The fifth embodiment differs from the second embodiment only in terms of the dummy sensor assembly 90, and only the differences will be described here.

In this embodiment the base plate 92 of the dummy sensor assembly 90 is considerably smaller, more particularly shorter in the length direction (i.e. vertically from the perspective of Figure 16). Indeed, in this embodiment the base plate 92 does not extend as far as the location at which the first housing would project in the case of the sensor assembly 2. With the second dummy housing 96 received within the second recess 70 of the door keep 62, the base plate 92 does not overlap the first recess 68. The base plate 92 therefore has no need for an opening as found on the dummy sensor assemblies 90 of the first and second embodiments. Furthermore, as shown in Figure 17 the second dummy housing 96 of the dummy sensor assembly 90 is hollow, rather than being solid as is the case in the second embodiment.

Where in the foregoing description, integers or elements are mentioned which have known, obvious or foreseeable equivalents, then such equivalents are herein incorporated as if individually set forth. Reference should be made to the claims for determining the true scope of the present invention, which should be construed so as to encompass any such equivalents. It will also be appreciated by the reader that integers or features of the invention that are described as preferable, advantageous, convenient or the like are optional and do not limit the scope of the independent claims. Moreover, it is to be understood that such optional integers or features, whilst of possible benefit in some embodiments of the invention, may not be desirable, and may therefore be absent, in other embodiments.

Claims

1. A sensor assembly configured for attachment to a door keep, the sensor assembly comprising: a base plate defining a front surface for facing towards a face plate of a door lock, and a rear surface for mounting against a door keep; a first housing projecting from the rear surface of the base plate, the first housing containing bolt sensor circuitry for detecting the presence of a locking bolt of said door lock; and a second housing projecting from the rear surface of the base plate, the second housing defining a battery compartment, wherein the first housing and the second housing project from the rear surface of the base plate separately from one another so as to define a gap therebetween.

2. A sensor assembly according to claim 1 wherein the bolt sensor circuitry comprises an inductive sensor for sensing the presence of a metal locking bolt.

3. A sensor assembly according to claim 1 or claim 2 further comprising door sensor circuitry for detecting the presence of a door that comprises said door lock.

4. A sensor assembly according to claim 3 wherein the door sensor circuitry is provided in the second housing.

5. A sensor assembly according to claim 3 or 4 wherein the door sensor circuitry comprises a Hall effect sensor for detecting the presence of a magnet provided on said door.

6. A sensor assembly according to any preceding claim wherein the first housing projects from the base plate along a first axis, the second housing projects from the base plate along a second axis, and the first and second axes are substantially parallel to one another.

7. A sensor assembly according to any preceding claim wherein one of the first and second housings projects further from the base plate than the other.

8. A sensor assembly according to claim 7 wherein the second housing projects further from the base plate than the first housing, and wherein the second housing is substantially cylindrical.

9. A sensor assembly according to any preceding claim wherein the base plate defines an opening for receipt of said locking bolt therethrough, and wherein the first housing is positioned at an edge of said opening.

10. A sensor assembly according to claim 9 wherein the opening is an aperture.

11. A sensor assembly according to claim 9 or 10 wherein the opening is opensided.

12. A sensor assembly according to claim 11 wherein: the base plate extends along a length direction, the first housing and second housing being spaced apart from one another along the length direction; the base plate extends across a width direction which is substantially perpendicular to the length direction; and the opening is open-sided in the width direction.

13. A sensor assembly according to any one of claims 9 to 12 wherein the first housing defines a surface which faces generally towards the opening, and the sensor assembly further comprises a reset button positioned on that surface.

14. A sensor assembly according to any preceding claim further comprising an electrical conductor extending between the first and second housings, the electrical conductor being encased in potting compound.

15. A sensor assembly according to any preceding claim further comprising wireless communications circuitry.

16. A sensor assembly according to any preceding claim wherein the first housing and the second housing have different cross-sectional shapes to one another.

17. A door keep configured for engagement with a sensor assembly according to any preceding claim, the door keep comprising: a mounting surface configured for engagement with the rear surface of the sensor assembly; a first recess extending through the mounting surface, the first recess being configured to receive the first housing of the sensor assembly and said locking bolt of said door lock; and a second recess extending through the mounting surface, the second recess being configured to receive the second housing of the sensor assembly.

18. A door keep according to claim 17 wherein the first recess and the second recess extend separately from one another so as to define a portion of material therebetween, the portion of material being shaped for receipt within the gap defined by the sensor assembly.

19. A door keep assembly comprising a sensor assembly according to any one of claims 1 to 16, and a door keep according to claim 17 or 18.

20. A door keep assembly comprising a door keep according to claim 17 or 18 and a dummy sensor assembly which does not comprise bolt sensor circuitry.

21. A door keep assembly according to claim 20 wherein the dummy sensor assembly comprises: a base plate defining a front surface for facing towards said face plate of said door lock, and a rear surface for engagement with the mounting surface of the door keep; and a second dummy housing projecting from the rear surface of the base plate and shaped for receipt within the second recess of the door keep.

22. A door keep assembly according to claim 21 wherein the second dummy housing is the only component to project significantly from the rear surface of the base plate.

23. A door keep assembly according to claim 21 wherein: the dummy sensor assembly further comprises a first dummy housing projecting from the rear surface of the base plate and shaped for receipt within the first recess of the door keep along with said locking bolt; and the first dummy housing and the second dummy housing project from the rear surface of the base plate separately from one another so as to define a gap therebetween.

24. A method of assembling a door keep assembly according to claim 19, the method comprising: providing the door keep and the sensor assembly separately from one another; inserting the first housing of the sensor assembly into the first aperture of the door keep and inserting the second housing of the sensor assembly into the second aperture of the door keep; and securing the rear surface of the base plate of the sensor assembly against the mounting surface of the door keep.

25. A method according to claim 24, wherein the step of providing the door keep and the sensor assembly separately to one another comprises providing a door keep assembly according to any one of claims 20 to 23 and then removing the dummy sensor assembly from the door keep.