AU710327B2

AU710327B2 - Spindle lock

Info

Publication number: AU710327B2
Application number: AU25153/97A
Authority: AU
Inventors: Ernest Gilbert Houghton
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-04-11
Filing date: 1997-04-10
Publication date: 1999-09-16
Anticipated expiration: 2017-04-10
Also published as: GB2328474B; CA2261260A1; GB2328474A; EP0954662A1; AU2515397A; GB9821449D0; WO1997038190A1; GB9706218D0

Description

SPINDLE LOCK This Application relates to a lock, in particular, a lock for use with a door handle of the type including a spindle.

Many-doors are furnished only with a door latch operated by handles which may lever handles or door knobs.

Should such a door need to be locked it is necessary to fit an independent lock, e.g. a deadlock comprising a slide bolt and keep or cabin hook and keep which requires new holes to be made in the face of a door. Alternatively, the handle has to be changed to one including a lock such as a mortis type deadlock. In this case the original handles are redundant and therefore wasted.

G.B. Patent No. 1145863 describes an escutcheon lock in which a bolt is engageable with a plate carried on a handle spindle to lock the handle. The bolt moves with a guide member which has projections engageable with recesses in the escutcheon plate in both the locking and unlocking positions of the bolt to prevent inadvertent movement of the bolt. The action of moving the bolt releases the projections from the recesses.

U.S. Patent No. 2576440 describes a lock with a manually operated locking plate with contiguous apertures in a first of which the handle spindle can freely move but in the second of which it is restrained. The locking plate is manually moved to the locking position by use of a thumb plate. The spindle has a cut out which can rotate in the second aperture and is located therein by forcefully pushing or pulling the handle to afford emergency entrance.

It is an object of this invention to provide a lock which can be retrofit to an existent door handle of the spindle type.

A lock for use with a door handle of the type including a spindle, the lock comprising a locking washer including an aperture of substantially the same crosssection as the handle spindle, a locking bar cooperating with the locking washer such that rotation of the latter causes rotation of the former, and, a stop for preventing Q4d rotation of the locking bar.

The advantage of this is ,har the lock can be retrofit to a door handle, between the handle and the door on one side, with the spindle extending through the locking washer aperture. The stop means then prevents rotation of the locking bar and locking washer and thus of the spindle.

The arrangement is equally applicable to new door handles which can thus be provided by the manufacturer in lockable form.

In one embodiment the locking washer and locking bar are integral and the locking washer may include a second aperture contiguous with the first but dimensioned such as to allow free rotation of the handle spindle therein. Locking and unlocking are achieved by moving the integral locking bar and washer relative the spindle so that it is located in, respectively, the spindle-shaped WO 97/38190 PCT/GB97/00994 2 aperture and the second aperture. This is a simple but effective mechanism for providing a door latch with a locking facility.

In a second embodiment, the locking washer and locking bar are separate but connectable. For example, the locking washer may include at least one cut-out on an outer edge thereof for receipt of an end of the locking bar, such as to cause joint rotation of the two parts. This embodiment is particularly suitable for providing a childproof lock, the washer being arranged to rotate with the latch spindle when the locking bar is not engaged and being prevented from rotation on engagement of the locking bar. The locking bar can be kept in a safe place away from a child when locking is not required.

Preferably with either of the above embodiments, one end of the locking bar cooperates with the locking washer and the other end of the locking bar includes at least one finger plate for applying pressure on the bar to cause axial movement thereof. In the first embodiment described above, the finger plate is used to move the locking bar and hence the locking washer relative the latch spindle. In the second embodiment described above, the finger plate is also used to move the locking bar into and out of engagement with the locking washer.

In another embodiment the portion of the locking washer defining the aperture is formed of metal, the remainder of the locking washer and the locking bar being formed of a plastic. This embodiment has cost advantages due to the use of plastic for the majority of the lock. It has been found that the stresses imposed by attempted rotation of the latch spindle can be sufficiently retained by a metal insert held within a plastic lock.

For all embodiments, the lock preferably also includes a fixing mount fastenable to a door, the mount defining at least one recess for receiving the locking washer and the locking bar, such that at least the locking bar is movable relative the mount and wherein the stop WO 97/38190 PCT/GB97/00994 3 means comprises at least one edge of the recess. The fixing mount means that the door does not need to be cut into and the only impact on the door is through fasteners used to secure the mount thereto. However, it will be appreciated that the recess for the locking washer and the locking bar could be provided in the door itself.

The depth of the recess is preferably less than the thickness of the mount, such that the locking bar and locking washer are held between the mount and the door to which it is attached.

Very preferably, latch means is provided for fixing the locking bar against movement relative the mount. The latch means may comprise a tab mounted on the locking bar engagable with at least one cut-out on an edge of the recess, the locking bar including a flexible portion movement of which releases the tab from engagement with the cut-out. This type of latch means provides a child safety feature, as axial movement of the locking bar must be accompanied or preceded by deflection of the flexible portion of the bar, a dual movement which it is difficult for children to achieve.

The mount may include alarm means activated by attempted rotation of the locking washer and/or locking bar.

An emergency release bar may be provided, connected by a cross-piece to the locking bar such that axial movement of the emergency release bar causes axial movement of the locking bar. Thus if the lock is used, for example, on a bathroom and concern arises with the health of someone within the bathroom, the lock may be released by use of the emergency release bar.

The invention will now be further described by way of example with reference to the accompanying drawings in which: Figure 1 is a front view of a first embodiment of a lock; Figure 2 and Figure 3 illustrate the operation of WO 97/38190 PCT/GB97/00994 4 the lock of Figure 1; Figures 4, 5 and 6 show various forms of a fixing mount for use with the lock of Figure 1 in prospective view; Figure 7 is an exploded view illustrating fitting of a lock of Figure 1 to a knob handle; Figures 8 and 9 are perspective views illustrating use of a lock of Figure 1 with a lever handle and a knob handle; Figure 10 is a perspective view showing a lock of Figure 1 in use with a modified spindle; Figure 11 is a perspective view of a lock of Figure 1 and a fixing mount for use therewith; Figures 12 to 15 illustrate various forms of a second embodiment of a lock; Figure 16 illustrates two alternative forms for a fixing mount for use with a lock of Figures 1 and 12 to Figure 17 illustrates two alternative forms of a third embodiment of a lock; Figure 18 illustrates a further alternative form for a fixing mount for use with a lock of Figures i, 12 to and 17; Figure 19 is an exploded view of a fourth embodiment of a lock; Figures 20 and 21 illustrate the lock of Figure 19 in use; Figure 22 illustrates an alternative form of the lock of Figure 19; Figure 23 illustrates a fifth embodiment of a lock; Figure 24 shows two alternative forms for a sixth embodiment of a lock; Figure 25 shows two alternative forms of a fixing mount for use with a lock of the sixth embodiment; Figure 26 and Figure 27 illustrate further alternative forms for the sixth embodiment of a lock and fixing mounts for use therewith; Figure 28 shows a front and side view of a lock WO9738190 PCT/GB97/00994 incorporating an alarm; Figures 29 and 30 illustrate fixing mounts which additionally act as finger plates; Figure 31 illustrates a fixing mount with a keyhole draught excluder; Figure 32 illustrates a further form for a lock of the sixth embodiment; Figure 33 shows front and side views of a fixing mount and a seventh embodiment of a lock; Figure 34 illustrates an alternative form for a lock of the seventh embodiment; and Figure 35 illustrates an eighth embodiment of a lock.

The lock 2 shown in Figure 1 comprises a locking bar 4 and locking washer 6. The locking bar 4 has a flange 8 at the end opposite that connected to the locking washer 6 which serves as a finger plate to allow movement of the locking bar 4.

The locking washer 6 includes a first aperture the cross-section of which is generally square and similar to that of a spindle, and a second aperture 12 contiguous with the first aperture 10. The second aperture 12 is of greater overall cross-section than the first aperture and is generally circular, the two apertures 10, 12 together forming a keyhole shape.

The lock 2 may be retrofitted behind an existing lever handle or door knob already provided for a door latch. This is illustrated by Figures 7 to 9. The knob 14 or lever handle 16 is first removed from the door 18. A fixing mount in the form of a fixing plate 20 is secured to the door 18 by screws or the like, apertures 22 being provided in the fixing plate 20 for this purpose. Prior to securement of the fixing plate 20 to the door 18, the lock 2 is positioned in a recess 24 in the rear of the fixing plate 20. The lock 2 is positioned such that the second aperture 12 is aligned with a correspondingly sized aperture 26 in the fixing plate 20. These aligned WO 97/38190 PCT/GB97/00994 6 apertures 12 and 26 are then positioned against the door such that the spindle 28 of the latch passes therethrough.

The knob 14 or lever 16 is then reattached to the spindle 28.

With the lock 2 in the position illustrated in Figures 2 and 7, the spindle 28 is free to rotate and so the handle can be turned and the door 18 opened and closed.

When the lock 2 is manually pushed by applying pressure on the finger plate 8, the spindle 28 enters the first aperture 10, as illustrated in Figures 3 and 9. An attempt to turn the handle will apply a rotary force on the locking washer 6 and thence the locking bar 4. The locking washer 6 and locking bar 4 will however be prevented from turning by one or other edge of the recess 24. The door latch will thus be deadlocked in its keep.

To release the spindle 28, the locking bar 4 is simply moved backwards through the fixing plate 20 until the second aperture 12 again receives the spindle 28. The knob 14 or lever 16 can then be turned in the normal way.

As illustrated in Figures 4 to 6 the fixing plate can be circular or oblong according to the type of handle behind which it is to be fitted and may be provided with a keyhole 32. The holes 22 in the fixing plate will be arranged to align with those of the mount 34 for the handle.

Should the need arise to enter a room because of an emergency, then the handle on the other side of the door from that to which the lock 2 is fitted can be removed, the spindle 28 pulled out far enough to be released from the locking washer 6 and then turned, so removing the latch from its keep.

However, it may be desired that the lock 2 not be deactivatable through the above described procedure. To prevent this and provide greater security, a modified spindle can be provided, as illustrated in Figure 10. The spindle 28a has a reduced thickness portion 36 in the region at which the lock 2 is fitted. As a result, if the WO 97/38190 PCT/GB97/00994 7 handle on the other side of the door is removed, the spindle 28 would be held by the lock 2 preventing it from being pulled through.

Figure 11 illustrates an alternative fixing mount 38 to the fixing plate 20 of Figures 4 to 9. The fixing mount 38 comprises a frame with a main portion 40 including hollow legs 42. An extension portion 44 includes legs 46 which are telescopically received in the legs 42 of the main portion 40. As a result the fixing mount 38 is extensible and accommodates handle plates of different depths. The legs 42 both include recesses 48 for receiving the lock 2 and this can therefore be fitted in either direction to make it left or right-handed. Upper and lower recesses 50 may also be provided to allow transverse fitting of the lock 2. Screw holes 52 enable connection of the mount 38 to a door by the user.

Figures 12 to 15 illustrate a second embodiment of a lock 62. As in the first embodiment, the lock 62 comprises a locking bar 64 and a locking washer 66 but the two are separately formed. The locking bar 64 is again provided with a finger plate 68. The locking washer 66 has a first spindle-shaped aperture 70 but no second aperture.

Instead the locking washer 66 is provided with at least one cut-out 72 for receipt of the free end of the locking bar 64, as illustrated in Figures 12 and 13. Alternatively, as illustrated in Figures 14 and 15, the locking washer 66 has at least one tongue 74 which is received in a cut-out 76 at the free end of the locking bar 64.

With the second embodiment, the lock 62 is retrofit by sliding the locking washer 66 over a handle spindle and then securing a fixing mount to the door, the mount being provided with a recess which, in the region of the locking washer 66, is of sufficient size to accommodate rotation of that locking washer 66. As retrofit with the locking washer 66 alone in place the handle can freely be turned.

To lock the handle the locking bar 64 is slid into the recess in the fixing mount and engaged with the locking WO 97/38190 PCT/GB97/00994 8 washer 66 through engagement of its end with a cut-out 72 provided on the locking washer 66, or engagement of a cutout 76 on the end of the locking bar 64 with the tongue 74 provided on the locking washer 66. Outside the region of engagement, the portion of the recess of the fixing mount in which the locking bar 64 moves will be sized only to allow axial movement of the locking bar 64 and not rotational movement. Thus with the locking bar 64 engaged with the locking washer 66 the handle is deadlocked. When not required the locking bar 64 can be kept in a safe place away from children.

Figure 16 shows two further alternative fixing mounts, both referenced 78, which like that of Figures 4 to 9 takes the form of a plate. The recess 80 however extends the full depth of the plate. With these mounts 78 the lock 2 will be constrained on its faces by the door on the one hand and the handle plate on the other.

Figure 17 shows a third embodiment of a lock 82.

The lock 82 is in two parts having, like the second embodiment, a locking bar 84 and locking washer 86. The locking washer 86 however includes both a first spindleshaped aperture 90 and a second larger aperture 92 like the first embodiment. The regions of the locking washer 86 defining the two apertures 90, 92 are connected by a line of weakness 94.

With the third embodiment of the lock 82 the user has the option of employing the lock as supplied, shown on the left hand side of Figure 17, in the way illustrated in Figures 7 to 9 or, prior to retrofitting, snapping the locking washer 86 at the line of weakness 94 to convert the lock 82 to a childproof form shown on the right hand side of Figure 17 which can be removed when not in use. The two views of Figure 17 also illustrate alternatives for finger plates 96 which enable manual movement of the locking bar 84 and locking washer 86.

Figure 18 shows the lock 82 of the left hand side of Figure 17 with a still further alternative finger plate WO 97/38190 PCT/GB97/00994 -9 96 fitted over a spindle 28 in the recess 24 of a fixing mount in the form of a fixing plate 20. The illustrated fixing plate 20 has two cut-outs 98 for passage of fixing screws 99 and an aperture 100 for a positioning screw 01.

The fixing plate 20 is held in position on a door by the positioning screw 101 and then secured to the door along with the handle 16 by the handle mounting plate 36 using screws 99.

Figures 19 to 21 illustrate a fourth embodiment of a lock 102. In this embodiment the lock 102 is similar to the first embodiment illustrated in Figures 1 to 9 but is provided with a transverse cross-piece 104 and an emergency release bar 106. The lock 102 is fitted on one side of a door 18 in the way illustrated in Figures 1 to 9 but a through hole 108 is formed in the door 18 for receiving the cross-piece 104. The emergency release bar 106 is fitted to the end of the cross-piece 104 on the other side of the door 18. The fixing mount 110 used with the lock 102 has an enlarged recess 112 to accommodate the cross-piece 104.

A second fixing mount 114 is employed on the other side of the door 18 for receiving and guiding the emergency release bar 106.

As will be appreciated from Figures 19 to 21, when a door has been locked using the lock 102 it can be released from the other side by movement of the emergency release bar 106. Figure 22 illustrates how the emergency release bar 106 can be made in a form which is removed when not required by making the aperture 116 which receives the cross-piece 104 open ended.

Figure 23 illustrates a fifth embodiment of a lock 122. The lock comprises a locking bar 124 and a locking washer 126. In this case the locking washer 126 is provided as a plate suitably made from plastics material with a metal insert 128 therein for receiving the spindle.

The metal insert 128 gives added strength and reduces wear on the locking washer 126. The locking washer plate 126 includes integral generally L-shaped flanges 130 which WO 97/38190 PCT/GB97/00994 together define a T-shaped recess 132. The locking bar 124 is also made from plastics material and is generally

U-

shaped. Each arm carries a finger plate 134 to allow the arms to be pushed together and has at its end a wedge shaped projection 136. In addition, one arm is provided with a tab 138.

The fixing mount 140 is in the form of a plate with a cut-out 142 shaped to receive the locking washer plate 126 and a contiguous recess 144 shaped to allow sliding movement of the locking bar 124 therein. The cut-out 142 has grooves 143 on its upper and lower edges for receiving and guiding correspondingly shaped edges 143a of the locking washer plate 126.

The lock 122 illustrated in Figure 24 operates in a similar fashion to that illustrated in Figures 1 to 9 but like that illustrated in Figures 12 to 15 has a removable locking bar 124.

The locking bar 124 is attached to the locking washer plate 126 by pressing the plates 134 together to draw the wedge shaped protrusions 136 together so that they may be inserted through the recess 144 and into the leg of the T-shaped recess 132 of the locking washer plate 126 held in the cut-out 142. Once past the legs, release of the plates 134 causes the wedge shaped protrusions 136 to spring back and latch in the cross-piece of the T-shaped recess 132 thus connecting the locking bar 124 and the locking washer plate 126. The two parts can be released by reversing the operation.

In use the mount 140 is fitted to a door with the spindle in the locked position passing through the spindleshaped aperture of the insert 128 of the locking washer plate 126. To release the spindle, the locking bar 124 is inserted into the fixing mount 140 through the recess 144 and engaged with the locking washer plate 126 as described above. In the engaged position the tab 138 latches against the mount 140 above the recess 144 and prevents release of the lock 122 without squeezing of the locking bar 124.

WO 97/38190 PCT/GB97/00994 11 To unlock the door the locking bar 124 is squeezed using figure plates 134 and pulled out drawing with it the locking washer plate 126 and thus releasing the spindle to turn freely. The tab 138 passes through the recess 144 and locates on the outside of the fixing plate 140. This prevents the locking bar 124 from being pushed back into the fixing plate 140. The locking bar 124 can remain secured to the locking washer plate 126 or can be removed completely by squeezing the finger plates 134 again to disengage it from the locking washer plate 126. Once the locking bar 124 is removed the lock 122 cannot be set.

Friction between the locking washer plate 126 and the fixing plate 140, through interaction of the grooves 143 and edges 143a, will stop the locking bar plate 126 from moving and thus accidental activation of the lock.

To set the lock 122 again, the locking bar 124 is inserted through the fixing plate 140 and engaged with the locking washer plate 126. The locking bar 124 is then used to push the locking washer plate 126 into the position where the spindle is deadlocked. The locking bar 124 can remain in this position or can be disengaged to make the lock 122 childproof.

Figure 24 illustrates a sixth embodiment of a lock 132. The lock 132 illustrated on the left hand side of Figure 24 operates in a similar fashion to that illustrated in Figures 1 to 9. A removable form is illustrated on the right hand side of Figure 24. In both cases the lock 132, like that of Figure 23, incorporates an additional safety feature in the form of a latch. For lock 132 the latch comprises a cantilevered arm 144 formed integrally with the locking bar 134, the arm having a tab 146. The other part of the latch is provided by forming the recess 148 in the fixing mount 150 with a groove 152 on one edge of the recess 148 as shown in Figure Both the main portion of the locking bar 134 and the cantilevered arm 144 are provided with finger plates 138 upstanding therefrom. On insertion of the locking bar WO 97/38190 PCT/GB97/00994 12 134 and the locking washer 136 into the recess 148 of the fixing mount 150, the tab 146 engages the edge of fixing mount 150 at the side of the mouth of the recess 148. The tab 146 is located relative the locking washer 136 such that it engages the locking mount 150 at the mouth of the recess 148 when the locking washer 136 is positioned so that the spindle passes through the larger aperture 142 thereof. Thus the lock 132 is secured in the unlocked position by the tab 146.

To move to the locked position requires the squeezing together of the finger plates 138 and sideways pressure on the locking bar 134 to move the locking bar 134 and locking washer 136 into the recess 148 with the tab 146 riding along the edge of the recess 148 through flexing of the cantilevered arm 144. The tab 146 engages with the groove 152 when the locking washer 136 is positioned so that the spindle engages with the spindle-shaped aperture 140 thereof. Thus the engagement of the tab 146 with the groove 152 secures the lock 132 in the locked position.

To release the latch and allow movement of the locking bar 134 it is necessary again to squeeze the finger plates 138 together to pull the cantilevered arm 144 towards the main portion of the locking bar 134. The pressure has to be maintained at least during initial moving of the locking bar 134 with the result that two different actions are required to move the lock 132 from the locked to the unlocked state and vice versa. This is difficult for a child to achieve and renders the lock illustrated in Figures 24 and 25 effectively childproof.

Figure 26 shows an alternative form for the lock 132 in which the locking bar 134 as a whole is formed as a cantilevered arm connected to the locking washer 136. The recess 148 in the fixing mount 150 has a narrowed mouth 154 for passage of the locking bar 134 alone, the locking washer 136 being retained within the recess 148. The mouth 154 is formed with the groove 152 for receiving the tab 146 with the locking washer 136 in the locked position.

WO 97/38190 PCT/GB97/00994 13 Figure 27 shows front and side views of a still further form of the sixth embodiment of the lock 132. In this case the locking washer 136 only includes spindleshaped aperture 140 which reduces costs. Like the embodiment of Figure 23, the locking washer 136 is in the form of a plastic plate with a metal insert 156 around the aperture 140 to resist wear from the spindle 28. The locking washer plate 136 moves along and is guided by grooves 158 in the recess 148.

Figure 28 illustrates how the fixing mount may be modified to incorporate an alarm 160. This is shown with reference to a fixing mount 78 of the form illustrated in Figure 16 but as will be appreciate is applicable to other illustrated forms for the fixing mount. Any of the above described locks may be employed but for the purposes of illustration that of Figure 17 is shown in the arrangement of Figure 28. The alarm 160 includes a pressure pad actuator positioned in the recess 80 of the fixing mount 78 beneath the locking washer 86. When the lock 82 is engaged with the spindle 28 in the locked position, an attempt to turn the door handle will press the locking washer 86 against the pressure pad and sound the alarm. When the lock 82 is disengaged from the spindle 28 in the unlocked position no pressure will be put on the alarm pressure pad.

The arrangement illustrated in Figure 28 is designed to be retrofit on the outside of a nursery or a bedroom door. When a child is left to play or sleep in the room with the door locked, an attempt by the child to leave the room will activate the alarm warning the parent/guardian of the child's intent.

Figures 29 and 30 illustrate how the fixing mount can be provided in the form of a finger plate. Figure 29 shows a simple fixing mount of the type illustrated in Figure 16 with an open ended recess 80. Figure illustrates a fixing mount 162 with a closed recess 164 for use with a lock of the type illustrated in Figure 24 having a cantilevered arm 144. As shown in Figure 30, however, WO 97/38190 PCT/GB97/00994 14 the cantilevered arm 144 is provided on the upper part of the lock 132 and the recess 164 has cut-outs 166 for engagement by the cantilevered arm 144 in both the locked and unlocked positions. As will be appreciated, the locking bar 134 and cantilevered arm 144 are provided in this arrangement extending generally transverse to the locking washer 136.

Figure 31 shows how a fixing mount in the form of a fixing plate 20 as illustrated in Figures 4 to 6 can include a keyhole draught excluder 168.

It will be appreciated that, because the fixing mounts are formed with holes positioned to align with those already in a door for attachment of the handle they can advantageously be used to provide finger plates without the need to form additional holes in the door. The fixing mounts in themselves therefore provide finger plates very suitable for retrofitting.

Figure 32 shows an arrangement incorporating elements of those of Figures 17, 23 to 25 and 31. The fixing mount is in the form of the fixing plate 150 of Figure 25 but has two grooves 152 and includes a keyhole draught excluder 168. The lock, like the lock 82 of Figure 17, has a locking washer 86 formed with a line of weakness 94. However, similarly to the lock 132 of Figure 24 the locking bar has two cantilevered arms 144 each provided with a locking tab 146 for engagement with a groove 152.

To move the lock from the locked to the unlocked position and vice versa, both cantilevered arms 144 need to be squeezed towards a central arm 170 to release the tabs 146 from their engagement either with the edge of the fixing plate 150 around the mouth of the recess 148, or from the grooves 152.

Figure 33 shows a seventh embodiment of a lock 172 in which the locking bar 174 and locking washer 176 are moved by turning of a key 178. In this arrangement the fixing mount 180 is modified to include a deadlock 181 which, like a conventional deadlock, includes a tumbler WO 97/38190 PCT/GB97/00994 mechanism. In a conventional deadlock the tumbler mechanism moves a dead bolt out from the deadlock itself and into engagement with the keep and vice versa on turning of a key. In the deadlock 181, the locking bar 174 replaces the bolt and is moved relative the deadlock 180 on turning of key 182 in the deadlock 181.

The lock 172 is shown in Figure 33 in the unlocked position. To deadlock the spindle 28, the key 182 is inserted into the keyhole 183 of the deadlock 181 and turned, the locking bar is moved along the recess in the fixing mount 180 to engage the spindle 28 with the spindleshaped aperture in the locking washer 176. The locking bar 174 is held by the tumblers in the deadlock 181 and so is in itself effectively deadlocked.

The lock 172 can be fitted using extended bolts 186 which pass through the handle plate, the fixing mount 180, the door 18 and the handle plate on the inside of the door and are held by nuts 188.

The lock 172 provides a less expensive, easy to fit alternative to a mortis type deadlock. It enables effective locking of a door latch using a key of the type with which the public is familiar.

Figure 34 shows an alternative form of a key operated lock 172 in which the locking bar 174 moves horizontally. Like the lock 82 of Figure 28, it incorporates an alarm 160 but in this case the alarm 160 is intended to detect and warn of burglars.

The switch of the alarm 160 is positioned in the fixing mount 180 such that horizontal movement of the locking bar 174, on turning of the key 182, switches on the alarm 160 which is battery powered. The key 182 is then removed with the latch now being deadlocked and alarmed.

Should the handle be tried, the locking bar 174 will stop the spindle 28 from turning and pressure or movement of the locking bar 174 will activate the alarm 160.

Deadlocks are known which may be electronically activated, i.e. the bolt is moved in response to a signal WO 97/38190 PCT/GB97/00994 16 received from a remote transmitter rather than turning of a key. It will be appreciated that the lock 172 could be made remotely activable but incorporating a remote control deadlock in the fitting mount 180.

Figure 35 illustrates an eighth embodiment of a lock 192. In this embodiment the fixing plate 202 has two recesses, a first 204 for receiving the locking bar 194 and locking washer 196 and a second 206 for holding a pivotally mounted locking rod 208 with a latching tab 210 on one end which engages with a groove 212 formed in the locking washer 196. The latching tab 210 is released from the groove 212 by pivoting the locking rod 208. This is achieved by pushing down on a pusher bar 214 movable within a cavity in the fixing plate 202 into and out of the recess 206.

As illustrated in the Figure, the latching tab 210 engages with the locking washer 196 when the spindle-shaped aperture 200 engages the spindle 28. The locking rod 208 may be spring biassed to this position. To release the locking washer 196 to allow movement of the lock 192 to the unlocked position the pusher bar 214 must be moved downwardly in the sense of the Figure and at the same time the locking bar 194 must be pulled out. This requires a two-handed coordinated movement beyond the capabilities of small children.

The lock may be formed from metal or, as in some of the illustrated embodiments, the locking washer may be provided with a metallic insert which in use engages the spindle so allowing the remainder of the lock to be made from plastic. The metallic insert will resist bending and wear from the spindle.

It will be appreciated that the lock of any of the embodiments is suitable not only for retrofitting to an existent handle but also for supply with a new handle.

When supplied with a new handle, the handle plate can be dispensed with as the fixing mount can be used to carry out its functions.

WO 97/38190 PCT/GB97/00994 17 The lock in all embodiments provides for simple and effective deadlocking of a door latch. It has few parts which makes its manufacture cheap. Further, it is easy to fit even by an unskilled user and then to operate.

A

number of the embodiments of a lock incorporate childproof features.

Claims

1. A lock. for use with a door handle comprising a locking washer including an aperture of substantially the same cross-section as the handle spindle, a locking bar cooperating with the locking washer such that rotation of the latter causes rotation of the former, a stop for preventing rotation of the locking bar, a fixing mount fastenable to a door, the mount defining at least one recess for receiving the locking washer and the locking bar such that at least the locking bar is movable relative the mount between a first, locking, position and a second, unlocking, position and the stop comprising at least one edge of the recess, and latch means for fixing the locking bar against movement relative the mount between the first and second positions and/or vice-versa, wherein the latch means comprises at least one tab formed on one of the locking bar and an edge of the recess engageable with a cut-out formed in the other, the locking bar including a flexible portion movable to release the tab from engagement with the cut-out, characterised in that the movement of the flexible portion of the locking bar to release the latch means involves a different manual action to movement of the locking bar between the first and second positions whereby the latch means comprises a child-proofing device.

2. A lock for use with a door handle comprising a locking washer including an aperture of substantially the same cross-section as the handle spindle, a locking boar cooperating with the locking washer such that rotation of the latter causes rotation of the former, a stop for preventing rotation of the locking bar, and an emergency release bar and a cross-piece for connecting the emergency release bar to the locking bar in spaced relationship such that axial movement of the emergency release bar causes axial movement of the locking bar.

3. A lock as claimed in Claim 2 including a fixing mount fastenable to a door, the mount defining at least one recess for receiving the locking washer and the locking bar such that at least the locking bar is movable relative the mount and wherein the stop means comprises at least one edge of the recess.

4. A lock as claimed in Claim 3 wherein latch means is provided for fixing the locking bar against movement relative the mount.

A lock as claimed in any one of Claims 1, 3 or 4 wherein the depth of the recess is less than the thickness of the mount such that the locking bar and locking washer are held between the mount and a door to which it is attached.

6. A lock as claimed in any one of Claims 1, 3, 4 or wherein the mount includes alarm means activated by attempted rotation of the locking washer and locking bar.

7. A lock as claimed in any preceding Claim wherein the locking washer and locking bar are integral and wherein the locking washer includes a second aperture contiguous with the first dimensioned such as to allow free rotation of the spindle therein.

8. A lock as claimed in Claim 7 wherein the locking washer and locking bar are connected by a line of weakness snappable under manual pressure to separate the two.

9. A lock as claimed in any one of Claims 1 to 6 wherein the locking washer and locking bar are separately formed and wherein the locking washer includes a cut-out for receipt of an end of the locking bar such as to cause joint rotation of the two.

A lock as claimed in any preceding Claim wherein one end of the locking bar cooperates with the locking washer and wherein the other end of the locking bar includes at least one finger plate for applying pressure on the bar to cause axial movement thereof.

11. A lock as claimed in any preceding Claim wherein the locking washer or at least the part thereof defining the aperture is formed from metal. <r=