Field

The present disclosure relates to a lock for a door, and in particular to locks for doors in prisons and psychiatric hospitals.

Background

Locks for doors are widely used to ensure privacy and security. Broadly speaking, most door locks have a housing, a lock mechanism (for example, a keyed lock cylinder or thumb turn), and a bolt. A user can operate the lock mechanism which in turn moves the bolt between a locked (extended) position and an unlocked (retracted) position.

When fitted to a door that has a door leaf and a door frame, a lock as described above enables the door to be locked thus providing privacy and/or security. When locked, the bolt is received by a socket in the doorframe, thus substantially preventing movement of the door leaf relative to the door frame.

The primary aim of a lock is to provide security. In order to achieve security, locks are designed to prevent the bolt from moving into the unlocked position (other than by the intended mechanism, e.g. by use of a key). Moreover, locks are designed with redundancies and backup features, all of which are specifically configured to prevent unwanted retraction of the bolt into the housing.

In psychiatric hospitals and prisons, a problem exists that patients may wish to cause themselves harm by anchoring a ligature around an available anchor point in a room. The same problem may arise in facilities other than psychiatric hospitals or prisons.

When a door having a lock as described above is locked, the bolt provides a potential anchor point around which an individual may try to secure a ligature to cause themselves harm. In particular, an individual may pass a ligature (for example, a charging cable) between a gap between the doorframe and the door leaf, and around the bolt. Because the bolt is received in the socket of the door frame, it provides a very stable anchor point. In short, a problem with existing locks is that a ligature can be anchored around the bolt, thus enabling someone to cause themselves harm.

Additionally, in lower security psychiatric environments, a handle for operating the lock may be provided both on the inside of the door and on the outside of the door, such that the inhabitant of a room can open the door from the inside. However, the ability for the inhabitant of the room to control the lock gives rise to a further problem. In particular, the inhabitant may apply a force to the inside door handle, thereby preventing the door from being opened from the outside. As a result, medical personnel may not be able to access the room when the patient is in danger or attempting to cause themselves harm.

Summary

In a first aspect there is provided a lock for installation in a door leaf defining a first plane, the lock comprising: a housing; and a bolt moveable relative to the housing between a retracted position, and an extended position in which a distal portion of the bolt protrudes from an opening in the housing; wherein the distal portion of the bolt comprises at least one shoulder sloped in a plane parallel to the first plane, such that the bolt is moveable into the retracted position in response to a force applied to the shoulder.

For example, where the lock is installed in a vertically oriented door leaf, the at least one shoulder may comprise an upper sloped shoulder and/or a lower sloped shoulder, for example an upper sloped shoulder and a lower sloped shoulder.

By providing a shoulder that is sloped in a plane parallel to the first plane on the distal end of the bolt, a force applied to the distal end of the bolt in a direction parallel to the first plane will cause the bolt to move from the extended position to the retracted position - even if the force is applied in a direction perpendicular to the direction of movement of the bolt relative to the housing. Accordingly, whenever an individual tries to anchor a ligature around the distal portion of the bolt, the force applied to the distal portion of bolt by the ligature will cause the bolt to retract into the housing. For example, where the lock is installed in a vertically oriented door leaf, and a ligature is secured around the distal end of the bolt so as to apply a vertical (e.g. upwards or downwards) force to the distal end of the bolt, the slope of the at least one shoulder will cause the force to move the bolt into the retracted position. Accordingly, the anchor point is removed. This improves safety, by helping to prevent self-harm attempts.

The bolt may be moveable relative to the housing between the retracted and extended positions in a first (e.g. horizontal) direction parallel to the first plane, and the slope of the shoulder may be such that the bolt is moveable into the retracted position in response to a force being applied to the shoulder in a second (e.g. vertical) direction that is perpendicular to the first direction and parallel with the first plane. That is, the slope of the at least one shoulder may form an oblique angle with the first direction. As a result, when a force is applied to the sloped shoulder in the second direction, the resultant force on the bolt will include both a vertical component and a horizontal component. The horizontal component will thus drive retraction of the bolt.

The lock may be for installation in a door leaf that opens and closes in a third direction that’s perpendicular to the first and second directions. The sloped at least one shoulder may form an oblique angle with each of the first and second directions, and may be perpendicular to the third direction.

In some examples, the distal portion of the bolt may further be rounded in a plane defined parallel with the first and third directions. That is, the surfaces of the bolt parallel with the first plane may also be rounded at the distal end of the bolt. This may further help with retraction of the bolt when a force as described above is applied to it.

When the bolt is in the (fully) extended position, the slope of the at least one shoulder may extend at least to the opening. For example, the slope of the at least one shoulder may extend from the opening to a distal-most point of the bolt. The travel of the bolt in the distal direction may be limited to ensure that the slope of the shoulder coincides with the opening when the bolt is fully extended. The travel may be limited by at least one detent provided on an inner surface of the housing, the at least one detent configured to engage a corresponding surface of the bolt in the extended position. The slope of the at least one shoulder may in some examples also extend proximally from the opening when the bolt is in the extended position (for example, extend from within the housing to the distal-most point of the bolt).

The at least one shoulder may comprise a first (e.g. upper) shoulder and a second (e.g. lower) shoulder opposing the first shoulder.

The distal portion of the bolt may be rounded to form the at least one shoulder (e.g. rounded to form the first and second opposing shoulders).

The bolt may be resiliently biased into the extended position. This may be achieved by a spring, for example a helical spring or a leaf spring, coupled to the housing and to the bolt.

The lock may comprise a lock mechanism configured to engage the bolt and operable to selectively retain the bolt in the retracted position. The lock mechanism may comprise a locked configuration in which it engages the bolt and retains the bolt in the retracted position; and an unlocked configuration in which it is disengaged from the bolt such that the bolt is resiliently biased into the extended position.

The lock mechanism may comprise a follower, the follower including a cam configured to engage a corresponding surface on the bolt. The follower may be rotatable between a first rotational position in which the cam is disengaged from the bolt such that the bolt is resiliently biased into the extended position (e.g. the locked configuration of the lock mechanism); and a second rotational position in which the cam engages the corresponding surface on the bolt to retain the bolt in the retracted position (e.g. the unlocked configuration of the lock mechanism). The bolt may be moveable relative to the follower when the follower is in the unlocked position. The follower may be operable via a spindle, examples of which are provided below. The lock may further comprise a shroud arranged within the housing to conceal an interior of the housing when the bolt is in the retracted position. The shroud may extend proximally from the opening. The shroud may at least partially encase the bolt within the housing.

In a second aspect there is provided a lock for a door, the lock comprising: a bolt, a follower configured to operate the bolt, and a first spindle extending from a first side of the lock; wherein the first spindle is translatable relative to the follower between a first position in which the first spindle is rotationally coupled with the follower; and a second position in which the first spindle is rotationally decoupled from the follower.

The first spindle may be for attachment to a first handle on the first side of the lock, such that rotation of the follower can be operated by a first user via the first spindle. Because the first spindle is translatable into a second position in which it is decoupled from the follower, a second user can prevent the first user from jamming the lock by moving the first spindle into the second position. Accordingly, where the lock according to the second aspect is coupled to a door, the second user can prevent the first user from jamming the lock in order to gain access.

The lock may be for installation in a door leaf defining a first plane. The first spindle may be translatable in a direction perpendicular to the first plane.

The first spindle may be translatable into the second position via a second side of the lock opposing the first side of the lock. In some examples, the first spindle may only be translatable into the second position via the second side of the lock. That is, translation of the spindle may not be operable from the first side of the lock. For example, the first handle may be rotationally coupled with the first spindle and translationally decoupled/disengaged from the first spindle. The second side of the lock may comprise a push-button or pull-tab for translating the first spindle. For example, the push-button or pull-tab may be configured for moving the first spindle into the second position. The first spindle may be resiliently biased into one of the first position and the second position. For example, the first spindle may be resiliently biased into the first position.

The follower may comprise a square aperture, and the first spindle may comprise a corresponding square cross-section, such that the first spindle is able to drive rotation of the follower (when in the first position). The square cross-section may be disengaged from the follower when the first spindle is in the second position.

The follower may be part of a lock mechanism configured to operate a bolt of the lock. The follower may be operable to move the bolt between an extended position and a retracted position. For example, the follower may be operable to selectively retain the bolt in a retracted position. The bolt may be resiliently biased into an extended position. The follower may be rotatable between a first rotational position in which the follower is disengaged from the bolt and the bolt is resiliently biased into an extended position (e.g. locked configuration); and a second rotational position in which the follower engages the bolt and retains the bolt in a retracted position (e.g. unlocked configuration).

The lock may further comprise a second spindle extending from a second side of the lock; wherein the second spindle is rotationally coupled with the follower. The second spindle may be for attachment to a second handle on the second side of the lock, such that rotation of the follower can be operated by a second user via the second spindle. The second spindle may also comprise a square cross-section rotationally engaged with the square aperture of the follower.

The second spindle may be configured to be rotatable relative to the first spindle (for example rotatable relative to the first spindle when the first spindle is in the second position). The second spindle may be rotationally coupled with the follower when the first spindle is in each of the first and second positions.

The second spindle may be translationally coupled with the first spindle, such that translation of the second spindle relative to the follower causes (e.g. drives) translation of the first spindle relative to the follower. Translation of the second spindle (and by extension the first spindle) may be operable from the second side of the lock, for example via a button or pull-tab associated with the handle.

The translational travel of the second spindle may be limited so as to prevent rotational disengagement of the second spindle from the follower.

The first spindle may be resiliently biased into one of the first position and the second position. For example, the first spindle may be resiliently biased into the first position. The resilient biasing may be provided by a spring, for example a helical spring or a leaf spring.

The lock may comprise a first handle rotationally coupled to the first spindle on the first side of the lock. The lock may also comprise a second handle rotationally coupled to the second spindle on the second side of the lock.

The first handle may have a rotational range of motion that is less than that of the follower. That is, the rotational travel of the first handle may be limited to less than that of the follower. For example, the first handle may comprise at least one detent (e.g. at least one concealed detent) which restricts the rotational travel of the first handle such that it’s less than that of the follower. In some examples, the rotational travel of the follower may be relatively unrestricted. In some examples, the rotational travel of the first handle may be at least 5 degrees less than the rotational travel of the follower. This may further help to prevent the user of the first handle from jamming the lock, by ensuring that the first handle can’t be used to apply a torsional force on the first spindle which could prevent translational motion of the first spindle.

The first and second spindles may be translatable relative to the first and second handles. The second handle may comprise the push-button or pull-tab.

The first and second spindles may collectively form a split spindle. A split spindle may comprise a first spindle portion at a first end thereof and a second spindle portion at a second end thereof, wherein the first and second spindle portions are rotatable relative to one another. As the reader will understand, the first spindle portion may correspond with (and be functionally equivalent to) the first spindle as described above. Similarly, the second spindle may correspond with (and be functionally equivalent to) the second spindle as described above. The first spindle portion may be coupled to the second spindle portion via corresponding threads. Alternatively, one of the first spindle and the second spindle may comprise a cylindrical cavity for rotational engagement with a corresponding cylindrical protrusion of the other of the first spindle and the second spindle.

For example, the lock of the second aspect may comprise: a follower; and a split spindle comprising a first spindle portion extending from a first side of the lock and a second spindle portion extending from a second side of the lock; wherein the split spindle is translatable relative to the follower between a first position in which the first spindle portion is rotationally coupled with the follower; and a second position in which the first spindle portion is rotationally decoupled from the follower. The second spindle portion may be rotationally coupled with the follower in both the first position and the second position.

The first and second aspects may be combined. Further, the optional features of the first aspect may be combined with the second aspect, and vice versa. The first spindle and/or second spindle may extend through the follower in a direction perpendicular to the first plane.

For example, in a third aspect, there is provided a lock for installation in a door leaf defining a first plane, the lock comprising: a housing; and a bolt moveable relative to the housing between a retracted position, and an extended position in which a distal portion of the bolt protrudes from an opening in the housing; wherein the distal portion of the bolt comprises at least one shoulder sloped in a plane parallel to the first plane, such that the bolt is moveable into the retracted position in response to a force applied to the shoulder; the lock further comprising a lock mechanism operable to selectively retain the bolt in the retracted position, the lock mechanism comprising: follower configured to operate the bolt, and a first spindle extending from a first side of the lock; wherein the first spindle is translatable relative to the follower between a first position in which the first spindle is rotationally coupled with the follower; and a second position in which the first spindle is rotationally decoupled from the follower.

Any of the optional features as described above may be combined with the third aspect. The first spindle may extend through the follower in a direction perpendicular to the first plane.

Brief description of the drawings

Specific examples of the present disclosure will now be set out, with reference to the accompanying drawings, in which:

Figures 1a-1d respectively show a first, a second, a third and a fourth bolt according to the present disclosure;

Figure 2 shows a lock according to the present disclosure in an unlocked configuration;

Figure 3 shows the lock of Figure 2, with the bolt in an intermediate configuration;

Figure 4 shows the lock of Figures 2 and 3 in a locked configuration;

Figure 5 shows a perpendicular cross-section of the lock in Figures 2-4, with a spindle shown in a first position;

Figure 6 shows the perpendicular cross-section of Figure 5, with the spindle shown in a second position;

Figure 7 shows a front side of a handle for use in the lock of Figures 2-6;

Figure 8 shows a rear side of the handle of Figure 7; Figure 9 shows a lock according to a further example of the present disclosure; and

Figure 10 shows a split spindle for use with a lock according to the present disclosure.

Like references are used for like features in the drawings.

Detailed description

Figures 1a-1d show a number of bolt configurations for use with a lock according to the present disclosure. Also shown for Figures 1a-1d are a first direction H, and a second direction V. For illustrative purposes, the first direction H will be described below as the horizontal direction, and the second direction V will be described below as the vertical direction. In other words, the description below is orientation-specific, in the interest of providing a clear description of a working example of the lock according to the present disclosure. However, as the reader will appreciate, the lock according to the present disclosure could in practice be used in any orientation other than that described below.

Figure 1a shows a bolt 100 according to a first example of the present disclosure.

The bolt 100 is configured for movement relative to a housing (not shown in Figure 1) in the horizontal direction H. The distal end 106 of the bolt 100 is rounded to form a sloped upper shoulder 102, and a sloped lower shoulder 104. The distal portion 106 comprising the sloped shoulders 102, 104 is the portion of the bolt that protrudes from the housing when the bolt is in the extended (locked) position (c.f. Figure 2 below). Each sloped shoulder forms an oblique angle with each of the vertical direction V and the horizontal direction H. Each shoulder is parallel with the plane of the page in Figure 1a (which is parallel with the first plane of the first aspect described above).

Figure 1b shows a bolt 100’ according to a second example. As with the bolt 100, the bolt 100’ has a distal portion 106’ which includes a sloped upper shoulder 102’ and a sloped lower shoulder 104’. Again, each of the sloped shoulders 102’, 104’ forms an oblique angle with each of the horizontal direction H and the vertical direction V.

Shown in Figure 1b is a force F applied in a vertical (downwards) direction V to the upper sloped shoulder 102’ of the bolt 100’. Because of the slope of the shoulder 102’, where the bolt is constrained to move in the horizontal direction, the resultant force on the bolt 100’ includes a horizontal component and a vertical component. Therefore, where the bolt 100’ is constrained to move only in the horizontal direction, the force F will cause the bolt to move (retract) in the horizontal direction. As the reader will understand, the same principle applies to Figures 1a, 1c, 1d.

Figure 1c shows a bolt 100” according to a third example. The bolt 100” also has a distal portion 106”. Flowever, whereas the bolts 100 and 100’ include both a sloped upper shoulder and a sloped lower shoulder, the bolt 100” includes only an upper sloped shoulder 102”. When a vertical (downwards) force F is applied to the upper sloped shoulder 102”, the bolt 100” will similarly be caused to move in the horizonal direction.

Figure 1d shows a bolt 100”’ according to a fourth example. The bolt 100”’ is similar to the bolt 100” above, save for the fact that its distal portion 106”’ includes a sloped lower shoulder 104”’, rather than a sloped upper shoulder 102”.

Figure 2 shows a lock 200 according to the present disclosure. The lock 200 includes a bolt 100 according to Figure 1a. Flowever, as the reader will understand, the lock may alternatively include a bolt according to Figure 1b, 1c, or 1d. Repeated again on Figure 2 for illustrative purposes are the horizontal direction FI, and the vertical direction V.

The lock 200 comprises a housing 202, which in the unlocked configuration shown in Figure 2 fully conceals the bolt 100. The bolt 100 is operated via a locking mechanism 204 which includes a follower 206 and a spindle (not shown in Figure 2). The follower 206 includes a cam 208 configured to engage a proximal end of the bolt 100 to thereby operate movement of the bolt 100 relative to the housing 202. As can be seen, the follower comprises a square aperture 210 for receiving a square spindle.

The lock 200 also includes a helical spring 211 coupled to the housing and to the bolt 100 so as to resiliently bias the bolt 100 into an extended position as shown in Figure 4.

Face plate 212 of the housing 200 is configured in use to sit flush with an edge of a door leaf into which the lock 200 is installed. When installed, the rest of the housing 202 is concealed within the door leaf. For the purposes of the present disclosure, the plane which is parallel to the page in Figure 2 corresponds to the first plane as described in the first aspect.

As the reader will understand, the bolt 100 may additionally be operated by an off- the-shelf cylinder lock (not shown). The off-the-shelf cylinder lock may be accessible via opening 214 in the housing 202, and may actuate the bolt 100 via engagement surfaces 216, 218.

The bolt 100 comprises an elongate channel 220 proximal of the distal portion 106.

A pin 222 coupled to the casing 202 is located within the elongate channel 220, to thereby restrict the motion of the bolt 100 to the horizontal direction H. The helical spring 211 is secured at a first end thereof to the pin 222, and at a second end thereof to a distal end of the channel 220. Accordingly, the bolt 100 is restricted to movement in the horizontal direction between a retracted position (shown in Figure 2) and an extended position (shown in Figure 4). The helical spring 211 resiliently biases the bolt into the extended position.

As can also be seen from Figure 2, the locking mechanism 204 is vertically offset from the elongate channel 220. This is achieved by having a main bolt portion 100a, and an offset bolt portion 100b. The offset bolt portion 100b is vertically offset from the main bolt portion 100a and is attached to the main bolt portion 100a by a connecting portion 100c. The locking mechanism 204 is positioned adjacent the offset bolt portion 100b in order to operate the bolt 100 via the offset bolt portion 100b. Also shown in Figure 2 is a shroud 228. The shroud 228 comprises a first plate 230 and a second plate 332. The first plate 230 is located within the housing 202 and extends adjacent the upper edge of the bolt 100. The second plate 232 is located within the housing 202 and extends adjacent the lower edge of the bolt 100. The shroud 228 abuts the opening 226 from the inner side of the housing 202. Accordingly, even though a small gap exists between the bolt 100 and the housing 202 when the bolt is in the retracted position of Figure 2, the shroud 228 prevents access to the interior of the housing 202.

Figure 2 shows the lock 200 in an unlocked configuration. In this configuration, the follower 206 of the locking mechanism 204 is in a second rotational position in which the cam 208 engages a proximal surface 209 of the bolt 100 so as to retain the bolt 100 in the retracted position as shown in Figure 2. This corresponds to an unlocked configuration of the lock mechanism. In the retracted position, the bolt is fully concealed within the housing 202. In particular, the distal portion 106 of the bolt 100 does not protrude through the opening 226. The cam 208 overcomes the biasing force of the helical spring 211 to retain the bolt 100 in the retracted position. A detent 224 restricts the proximal motion of the bolt 100 so that it cannot extend any further proximally than the retracted position shown in Figure 2.

In order to move the lock into a locked configuration, a user operates the lock mechanism 204. In particular, the user operates the lock mechanism 204 in order to rotate the follower 206 away from the first rotational position of Figure 2, and into the first rotational position of Figure 4, via the intermediate rotational position of Figure 3. As the follower 206 rotates, the cam 208 moves in the generally distal direction, and the bolt 100 in turn also moves in the distal direction under the biasing influence of the helical spring 211.

Rotation of the follower 206 continues, until the follower 206 reaches the second rotational position shown in Figure 4. In this second rotational position, the follower 206 has rotated sufficiently for the cam 208 to completely disengage from the bolt 100, such that the bolt 100 can freely move under the influence of the helical spring 211 , without the cam 208 obstructing the horizontal movement of the bolt 100. As shown in Figures 2, 3 and 4, the proximal surface of the cam 208 is rounded so as to ensure that the cam does not interfere with the movement of the bolt 100 when the follower is in the second rotational position. An adjacent distal surface 225 of the bolt 100 is similarly rounded to prevent it from snagging on the cam 208 when the follower is in the second rotational position.

The helical spring 211 retains the bolt 100 in the extended position shown in Figure 4. This is the locked configuration of the lock 100.

In the locked configuration, the bolt 100 can be moved back into the retracted (unlocked) position either by applying a force to the distal end of the bolt 100, or by a user moving the follower 206 back to the first rotational position of Figure 2, such that the cam 208 once again engages the proximal surface 209 to retain the bolt 100 in the retracted position of Figure 2.

As can be seen from Figure 4, in the locked configuration in which the bolt 100 is in the extended position, the distal portion 106 of the bolt 100 having the sloped upper and lower surfaces 102, 104 protrudes from the opening 226 in the housing 202. If a force is applied in the upwards direction or the downwards direction to the distal portion 106 of the bolt 100, the sloped surfaces will cause the bolt 100 to retract back into the housing 202. Accordingly, as soon as an individual tries to suspend a weight from a ligature anchored around the bolt 100, the bolt 100 will move back into the retracted position shown in Figure 2, such that the anchor point is immediately removed. Once the force is removed, the bolt 100 will once again return to the extended position of Figure 4 under the influence of the helical spring 211.

Figure 5 shows a perpendicular cross-section of the lock 200 from Figures 2-4. The cross-sectional view of Figure 5 is taken along a horizontal plane that extends into the page in Figures 2-4, i.e. a horizontal cross-section taken through the door leaf 300 into which the lock 200 is installed.

Figure 5 shows the door lock 200 installed in a door leaf 300. The face plate 212 sits flush with a front edge of the door leaf 300. A split spindle 302 extends through the follower 206. The split spindle 302 has a square cross-section, for rotational engagement with the square aperture 210 of the follower 206. Accordingly, the split spindle 302 is operable to drive rotation of the follower 206 between the first rotational position (Figure 2) and the second rotational position (Figure 4) - i.e. is operable to lock or unlock the door. Moreover, a first end of the split spindle 302 is connected to a first handle 304, and a second end of the split spindle 302 is connected to a second handle 306. Accordingly, a user can operate the lock 200 from the first side 300a of the door (using the first handle 304), or from the second side 300b of the door (using the second handle 306).

The split spindle 302 includes a first spindle portion 302a, and a second spindle portion 302b. The first spindle portion 302a is rotationally coupled with the first handle 304; and the second spindle portion 302b is rotationally coupled with the second handle 306. The first portion 302a of the split spindle is attached to the second portion 302b of the split spindle by a threaded connection. Accordingly, the first and second portions 302a, 302b are translationally coupled with one another, but are able to rotate relative to one another. An illustration of such a split spindle 302 having a first spindle portion 302a and a second spindle portion 302b is shown in Figure 10.

With continued reference to Figure 5, the split spindle 302 is translatable relative to the follower 206, and relative to the first and second handles 304, 306. That is, the split spindle 302 is translatable between a first position as shown in Figure 5; and a second position as shown in Figure 6. A first lip 308 on the first spindle portion 302a and a second lip 310 on the second spindle portion 302b limit the translational movement of the split spindle 302 to being between the first position and the second position. A helical spring 311 resiliently biases the split spindle 302 into the first position as shown in Figure 5. The second handle 306 includes an opening 312. A user on the second side 300b of the door can push the second portion 302b of the spindle via the opening 312, to thereby move the split spindle 302 into the second position shown in Figure 6. When the user releases the second portion 302b of the spindle, it will then return to the first position as shown in Figure 5 under the biasing influence of the helical spring 311. The helical spring 311 is located within the first handle 304, and is coupled to the first portion 302a of the split spindle so as to bias the split spindle 302 into the first position. When the split spindle 302 is in the first position as shown in Figure 5, i.e. when a user on the second side 300b of the door leaf 300 is not pressing on the second portion 302b of the split spindle, both the first portion 302a and the second portion 302b of the split spindle are located within the follower 306. Accordingly, both are rotationally coupled with the follower. By extension, when the split spindle is in the first position as shown in Figure 5, both the first handle 304 and the second handle 306 are rotationally coupled with the follower. The lock can therefore be operated via both the first handle 304 and the second handle 306.

If a user on the first side of the door 300a holds the handle 304 so as to prevent it from rotating, the first portion of the spindle 302a - which is located within the follower 304 and thus rotationally coupled with the follower 304 when the split spindle 302 is in the first position of Figure 2 - will prevent unlocking of the door. Flowever, a user on the second side of the door can override the first handle 304 by pushing the split spindle 302 into the second translational position of Figure 6 via the opening 312. When the split spindle 302 is in the second translational position shown in Figure 6, the first portion 302a of the split spindle is no longer located within the follower 206. Accordingly, the first portion 302a of the split spindle - and by extension the first handle 304 - are no longer rotationally coupled with the follower 306. Accordingly, the user of the second handle 306 can override / disengage the first handle to unlock the door. A key may be provided for insertion into the opening 312 to enable easy override.

Figure 7 shows an example of the first handle 304. As illustrated, the handle 304 is configured to rotate by 40 degrees in a first direction, and by 40 decrees in a second direction. Accordingly, the total rotational travel of the handle is limited to 80 degrees. Figure 8 shows the reverse side of the handle 304 (the part which is concealed within use). A protrusion 330 and a corresponding arcuate channel 332 are shown. The protrusion 330 is attached to the door leaf 300 and extends into the channel 332 of the handle 304, in order to restrict the rotational travel of the handle 304 to 80 degrees as discussed above. The follower 206 is free to rotate by more than 80 degrees. Accordingly, a user of the handle 304 is not able to apply a torsional strain between the spindle 302 and follower 206. The user therefore is not able to seize the spindle 302 within the follower 206 to prevent translational movement of the spindle 302 relative to the follower 206. The follower 206 may be configured to have a rotational travel of at least 90 degrees, i.e. at least 5 degrees greater than that of the handle 304 in each direction.

Above, a lock 200 which combines the retracting bolt of the first aspect, and the translatable spindle of the second aspect, has been described. However, as the reader will understand, the lock mechanism (comprising the follower and the translatable split spindle) as described in detail in Figures 5-6 could be used with a conventional, off-the-shelf bolt. Similarly, the retracting lock arrangement described in detail in Figures 2-4 could be used with a conventional, off-the-shelf lock mechanism. Advantages are achieved by each of the first and second aspects of the present disclosure when considered alone. Additionally, the combination of the two aspects provides a synergistic lock system with even higher levels of user safety.

Figure 9 shows a lock 400 according to a further example, in a locked configuration. The lock 400 includes all of the features of the lock 200 described above. Like reference numerals are therefore used for like features / components. However, the lock 400 includes an additional feature. In particular, the lock 400 includes a roller latch 402. The roller latch 402 includes a roller 404 and a helical spring 404 arranged to bias the roller 404 into the extended position shown in Figure 9.

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.