GB2480258A

GB2480258A - Reconfigurable door lock for use on right hand and left hand side of doors

Info

Publication number: GB2480258A
Application number: GB1007777A
Authority: GB
Inventors: Terry Jackson; Stuart Carpenter
Original assignee: Assa Abloy Ltd; Paddock Fabrications Ltd
Current assignee: Assa Abloy Ltd
Priority date: 2010-05-10
Filing date: 2010-05-10
Publication date: 2011-11-16
Also published as: GB201007777D0

Abstract

A door lock comprising: a retractable latch 16; an independently operating mechanism on each side, each mechanism comprising a first element 26 to be rotated by a spindle of a handle, a second element 30 rotatable about the spindle, and a removable member such as a protruding peg 28 which can be installed on the first element 26. When the removable peg 28 is present rotation of the first element is transmitted to rotate the second element and retract the latch; when the peg is removed rotation of the first element is not transmitted to the second element. The removable member may be removed from the actuation mechanism on either side of the door lock, so that the latch can be retracted on one side only. In another aspect, a door lock comprises a reversible latch, wherein the reversible latch has a protruding, reversible tongue portion, a tail portion and an interlock. The tongue portion is secured to the tail portion in use so as to enable removal of the tongue portion from the tail portion and replacement of the tongue portion in a reversed 180 degree orientation. Preferably the distance the latch extends is adjustable the latch being extended to its outmost position before it can be reversed such as by a twist locking action (fig. 11).

Description

Improvements in Door Locks The present invention relates to door locks of the retractable latch type. More particularly, but not exclusively, the invention relates to door locks having a split spindle.

Door locks having a retractable latch are well known in which a spindle extends through the lock and is rotated by operation of a door handle. Rotation of the spindle causes retraction of the latch to open the door. The latch is usually spring mounted and asymmetric or "handed", having a flat face on one side and a curve or sloping face on the other side so that the door can be closed without having to turn the handle.

These locks usually also include a key-operated deadlock to lock the door. In a standard through-spindle lock the door can be opened from both sides. Split spindle door locks allow the door to be opened by operation of the handle only on one side (usually the indoor side of an exterior door), but require the additional operation of key in order to open the door from the other side. This adds a level of security in preventing a so-called "follow-through" intrusion after the key-holder has unlocked and passed through the door.

A problem with these types of known door lock is that they are "handed" in that they only operate in one direction. If the door should need to be changed, either so that it can be operated in the reverse direction, or remounted with the door hinges on the opposite side, then the lock also has to be changed. Suppliers of these door locks therefore have to stock both "handed" locks and delays arise if door fitters are supplied with incorrectly handed locks.

The present invention has been conceived with the foregoing in mind. *..* * * **..

According to a first aspect of the present invention there is provided a door lock having a retractable latch. The lock includes an actuation mechanism on each side of the door lock, each actuation mechanism being actuable independently by a respective door handle. Each actuation mechanism comprises: a first element that engages with a spindle of the respective door handle so as to be rotatable about the spindle axis and **** *..: includes a means for receiving a removable member; and a second element rotatable :: 35 about the spindle axis for retracting the latch. The removable member, when received in the first rotatable element engages the second rotatable element upon rotation of the respective door handle spindle so as to retract the latch. When the removable member is not received in the first rotatable element, rotation of the respective door handle spindle does not cause rotation of the second rotatable element. The removable member may be removed from the actuation mechanism on either side of the door lock, so that the latch can be retracted on one side only.

It is an advantage that removal of the removable member, from either of the actuation mechanisms, enables the lock to be used as a split spindle door lock from either direction. In other words, operation can be reversed by removing the removable member from the actuation mechanism on one side and inserting a removable member into the actuation mechanism on the other side.

In one embodiment a spindle opening extends through the door lock along the spindle axis of the door handle spindles. A spindle of a door handle on each side of the door can be inserted part way through the spindle opening to engage with the respective actuation mechanism.

The means for receiving the removable member may have a screw thread for receiving a corresponding screw thread on the removable member.

In one embodiment, the latch is handed to enable the door to be closed without operation to retract the latch, and to be opened only upon operation to retract the latch.

The latch may be reversible. For example, the latch may comprise a latch assembly wherein at least a portion of the latch can be removed and replaced in a reversed orientation. The latch assembly may include a twist-motion interlock wherein a twist motion enables the latch to be removed from the lock by twisting and withdrawing, and *S..

replaced into the lock by inserting and twisting.

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*SSS.. * *

* The latch may have an adjustable protrusion length, the latch being removable from the door lock only when adjusted to a limit of its protrusion length.

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The door lock may further comprise a key-operable mechanism for retracting the latch * 35 when the removable member is not received in the first rotatable element.

S..... * *

According to a second aspect of the invention there is provided a door lock comprising a reversible latch, wherein the reversible latch comprises a protruding, reversible tongue portion, a tail portion and an interlock whereby the tongue portion is secured to the tail portion in use so as to enable removal of the tongue portion from the tail portion and replacement of the tongue portion in a reversed orientation.

Preferably, the tongue portion is removable from the tail portion only in an extended position of the latch, the door lock further comprising an adjuster mechanism for moving the latch to the extended position. The adjuster mechanism may comprise an adjustment screw.

The interlock may be a twist-operation interlock, the tongue portion being removable from the tail portion by a twisting and withdrawing operation and replaceable in a reversed orientation by an inserting and twisting operation. In one embodiment, the interlock comprises mushroom head protrusions on one of said tongue and tail portions for engaging in corresponding slot openings in the other of said tongue and tail portions.

In aspects of the invention, the door lock may further comprising a dead lock. The dead lock may be operable by means of a key.

Embodiments of the invention are described below with reference to the accompanying drawings, in which: Figure 1 is a view in perspective of a door lock; Figure 2 is a view in perspective of the door lock of Figure 1 with a front face ** removed; S..... * *

.: Figure 3 is a side elevation view of the door lock as shown in Figure 2; Figure 4 is a view in perspective of the door lock of Figures 1 to 3 with the front *** face removed showing the latch in a retracted position; : * * S Figure 5 is a side elevation view of the door lock as shown in Figure 4; Figure 6 is a view in perspective of the door lock of Figures 1 to 3 with the front face removed and without a removable member in place; Figure 7 is a side elevation view of the door lock as shown in Figure 6; Figures 8 and 9 are side elevations of part of a door lock having a reversible latch mechanism; Figure 10 is a perspective view of part of the door lock of figures 8 and 9; Figure 11 is an illustration of parts of the latch of the door lock of figures 8 to 10.

Referring to Figure 1, there is shown a door lock 10, of a type that is mountable in a recess in the edge of a door. The lock has a front plate 12 and a rear plate 14 with the door lock mechanisms (only parts of which are visible in figure 1) mounted between the front and rear plates. A retractable latch 16, an a deadbolt 22 extend outwards from between the plates 12, 14 through the side of the lock 10 that is exposed on the edge of the door. When fitted to a door a face plate (not shown) covers the opening along this exposed side of the lock 10. Also shown in Figure 1 in the front plate 12 is a front spindle barrel 18 rotatably mounted in the lock 10 and having a spindle opening 20 for receiving a square spindle of a door handle (not shown). A second, rear spindle barrel (not visible) aligned with the front spindle barrel 18 is mounted in the rear side of the door lock 10. The door lock 10 also has a keyhole shaped opening 24 for receiving a key barrel (not shown).

The latch 16 shown in Figure 1, as well as in Figures 2, 4 and 6 described below is *.* S..... handed" in that it has a front flat face 16a, and a curved profile on the rear side 16b.

:: 30 When the door is closed the rear side profile strikes a strike plate mounted on the door * * frame which pushes the latch 16 back against a biasing spring (not shown in Figure 1).

This allows the door to be closed without the need for a person to retract the latch.

*.. . . . . . However, principles of the invention may be applied to locks having other types or shapes of latch. * 35

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Figures 2 and 3 show the door lock 10 of Figure 1 with the front plate 12 removed. The same features shown in Figure 1 have the same reference numerals. The spindle barrel 18 on each side of the lock 10 forms a part of a latch actuation mechanism. The latch actuation mechanism on each side of the door lock 10 is actuable only from that side. Only the mechanism that is actuable from the front side of the door is visible in the Figures. The other (rear side) actuation mechanism is a mirror image of, and disposed behind the one shown. The actuation mechanism includes a first rotatable element 26, which is engaged with the spindle barrel 18 so that operation of the door handle to rotate the spindle causes the first rotatable element 26 to rotate around the spindle barrel 18. The first rotatable element 26 has a threaded hole into which a removable screw member 28 is inserted. A second rotatable element 30 is mounted around the spindle barrel 18, but in this case is not in engagement with the spindle barrel 18. The second rotatable element 30 has an arm 32 which extends over a lug 34 on an inward portion the latch 16. The latch 16 is biased outwardly by a compression spring 35 (as shown in Figure 3) so that the lug 34 maintains contact with the arm 32 of the second rotatable element 30.

Figures 4 and 5 show the lock 10 in the situation where the latch 16 has been retracted by operation of the actuation mechanism on the front side of the lock 10. In this position movement of the door handle (not shown) rotates the spindle barrel 18. As shown, the square spindle opening 20 is rotated through about 45 degrees relative to the position shown in Figures 2 and 3. Rotation of the spindle barrel 18 has rotated the first rotatable element 26 until the removable screw 28 has contacted the second rotatable element 30. Further rotation has rotated the second rotatable element 30 causing the arm 32 to push the lug 34 and retract the latch 16 against the aforementioned biasing action.

Figures 6 and 7 show the lock 10 in the situation where the removable screw member 28 has been removed from the first rotatable element. Operation of the door handle : 30 (not shown) has rotated the spindle barrel 18 and first rotatable element 26 as above in Figures 4 and 5. However, because there is no screw member 28 to engage the second rotatable element 30, this has not moved, and the latch 16 has not been retracted. Initially, the removable screw members 28 are inserted into both of the front and rear actuation mechanisms, so that the door can be operated to retract the *S..

* 35 latch 16 from both sides. In order to allow the door to be opened by the door handle on * I one side only, the removable screw member 28 is removed from the actuation mechanism of the other side so that operation of the door handle on that side does not retract the latch 16. In other words by removing the screw member 28 from one side (fro example the front), the latch 16 can only be retracted by the door handle on the other (e.g. rear) side. Retraction of the latch 16 from the front side of the door can then only be achieved by operation of a key, as will be described further below. This provides the added level of security of a split spindle door lock. Note that the door handles on each side of the door require separate spindles, and these are required each to penetrate only far enough into the spindle barrel to operate the actuation mechanism on that side of the door.

A major advantage of the door lock 10 described above is that the removable screw member 28 can be taken out of, and so disable, the actuation mechanism on one side of the door lock and inserted into, so as to enable, the actuation mechanism on the other side. In other words, by simply swapping the screw member over to the other side, the one-sided actuation of a split spindle door lock can be reversed without having to fit a completely different lock.

Referring to Figures 6 and 7, in order to retract the latch with the use of a key, the lock 10 includes a push member 36, one end 38 of which engages a cam lobe of the key-operated mechanism (not shown) that is mounted through the keyhole-shaped opening 24. The other end 40 of the push member 36 contacts a cam arm 42 on the second rotatable element 30. Turning a key in the key-operated mechanism to rotate the cam lobe pushes the push member 36, which pushes the cam arm 42 causing the second rotatable element to rotate and retract the latch 16.

As referred to above, the latch 16 shown in Figures 1, 2, 4 and 6 is "handed".

Accordingly, if use of the lock is to be reversed, then the latch 16 will be incorrectly orientated in the lock. Figures 8 -12 illustrate a reversible latch that overcomes this *..I..

* * 30 problem. * **

S.:. As shown in Figure 8, a door lock 50 has a retractable latch assembly 52. Latch * assembly 52 includes an outer tongue portion 54, which protrudes through an opening in a face plate 56, and an inner tail portion 58. As described above for the *.** * 35 embodiments shown in Figures 1 to 7, the latch assembly 52 is retractable by operation

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of a door handle (not shown) to rotate a rotatable element 30, an arm 32 of the rotatable element 30 engaging on a lug 34 on the latch. Retraction of the latch assembly 52 by this mechanism would typically be against the action of the spring 35 biasing the latch outwardly of the lock. In this embodiment, the latch assembly 52 also carries an adjustment screw 60. The head of the adjustment screw 60 abuts a stop 61 on the rear of the face plate 56.

By adjusting the adjustment screw 60 the extent to which the latch mechanism protrudes in front of the face plate 56 can be varied. As shown in Figure 9, screwing the adjustment screw 60 all the way in allows the latch mechanism to extend so that the outer tongue portion 54 is clear of the front of the face plate 56. In this position, the tongue portion 54 can be removed from the tail portion 58. An example of how this is achieved is described below. It will be appreciated that although the adjustment screw is a convenient arrangement for enabling the latch assembly to be extended, other mechanisms could be employed, such as a simple two-position adjuster mechanism.

Figure 10 is a perspective view of the lock 50, in which the latch 52 has been fully extended, and shows the tongue portion 54 in the process of being removed from (or replaced into) the tail portion 58. In this case the removal/replacement is achieved by a twisting operation. Once removed, the orientation of the tongue portion 54 can be reversed (i.e. turned through 180 degrees) and replaced. As can be seen, the tongue portion 54 is "handed" having a flat front face 62, and a curved rear face 64. This allows the latch to retract by itself when the door is pushed closed by the action of a strike plate on the door frame against the curved face 64. However, in this case, the "handing" of the lock can be quickly and easily changed by reversal of the tongue portion 54 of the latch 52.

Note that, after attachment (or re-attachment) of the tongue portion 54 to the tail portion 58, the adjuster screw 60 is screwed out again to provide a stop position of the latch 52 :: 30 in which the tongue portion does not extend completely beyond the face plate 56 (i.e. * *, back to a position as shown in Figure 8). In this position the face plate 56 prevents :.: twisting of the tongue portion 54 so that it cannot accidentally or inadvertently become detached from the tail portion 58. **..

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Figure 11 shows an example of a twist-operation (or "bayonet" type) interlock between the tongue portion 54 and the tail portion 58. The body of the tongue portion 54 is shown in phantom so as to show a pair of "mushroom head" protrusions 66, 68. The tail portion 58 has a top face 70 and a pair of "keyhole" shaped openings 72, 74, which are spaced apart by the same distance as the protrusions 66, 68 on the tongue portion.

The tongue portion 54 is secured to the tail portion 58 by inserting the mushroom head protrusions into the keyhole shaped openings 72, 74, and then twisting the tongue portion 54. The openings 66, 68 in the tail portion 58 extend through to a cavity 76 behind the top face 70. The thickness between the top face 70 and the cavity corresponds to a spacing between the mushroom heads 66, 68 and the bottom face 78 of the tongue portion 54. Also, the narrow parts of the keyhole-shaped openings 72, 74 are narrow than the diameters of the mushroom heads of the protrusions 66, 68, so that when the tongue portion 54 is twisted into its operating position the mushroom heads become trapped inside the cavity 76, thereby securing the tongue portion 54 to the tail portion 58.

It will be appreciated that other types of interlock could be used. For example a sliding interlock or a threaded interlock. However, the above described bayonet-type twist-interlock provides a particularly quick and easy-to-use way of reversing the handing of the latch. It will also be appreciated that the bayonet-type interlock could have the protrusions on the tail portion and the openings for receiving the protrusions in the tongue portion. * 4 **.*

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Claims

CLAIMS: 1. A door lock comprising: a retractable latch; and an actuation mechanism on each side of the door lock, each actuation mechanism being actuable independently by a respective door handle, and each actuation mechanism comprising: a first element engageable with a spindle of the respective door handle so as to be rotatable about the spindle axis, and including a means for receiving a removable member; and a second element rotatable about the spindle axis for retracting the latch, wherein the removable member, when received in the first rotatable element engages the second rotatable element upon rotation of the respective door handle spindle so as to retract the latch, and wherein, when the removable member is not received in the first rotatable element, rotation of the respective door handle spindle does not cause rotation of the second rotatable member to retract the latch, and wherein the removable member is removable from the actuation mechanism on either side of the door lock so that the latch can be retracted on one side only.
2. The door lock of claim 1 further comprising a spindle opening extending through the door lock along the spindle axis of the door handle spindles, whereby a spindle of a door handle on each side of the door can be inserted part way through the spindle opening to engage with the respective actuation mechanism.
3. The door lock of claim 1 or claim 2 wherein the means for receiving the removable member has a screw thread for receiving a corresponding screw thread on the removable member. * b
4. The door lock of any preceding claim, wherein the latch is handed to enable the door to be closed without operation to retract the latch, and to be opened only upon * ** :.: *. operation to retract the latch. * *a. *
5. The door lock of claim 4 wherein the latch is reversible. *S.S * S
6. The door lock of claim 5 wherein the latch comprises a latch assembly wherein at least a portion of the latch to be removed and replaced in a reversed orientation.
7. The door lock of claim 6 wherein the latch assembly includes a twist-motion interlock wherein a twist motion enables the latch to be removed from the lock by twisting and withdrawing, and replaced into the lock by inserting and twisting.
8. The door lock of any of claims 5 to 7 wherein the latch has an adjustable protrusion length, the latch being removable from the door lock only when adjusted to a limit of its protrusion length.
9. The door lock of any preceding claim, further comprising a key-operable mechanism for retracting the latch when the removable member is not received in the first rotatable element.
10. A door lock comprising a reversible latch, wherein the reversible latch comprises a protruding, reversible tongue portion, a tail portion and an interlock whereby the tongue portion is secured to the tail portion in use so as to enable removal of the tongue portion from the tail portion and replacement of the tongue portion in a reversed orientation.
11. The door lock of claim 10, wherein the tongue portion is removable from the tail portion only in an extended position of the latch, the door lock further comprising an adjuster mechanism for moving the latch to the extended position.
12. The door lock of claim 11 wherein the adjuster mechanism comprises an adjustment screw.
13. The door lock of any of claims 10 to 12 wherein the interlock is a twist-operation interlock, the tongue portion being removable from the tail portion by a twisting and withdrawing operation and replaceable in a reversed orientation by an inserting and * ** :.: * twisting operation. *. S... *555 S *
14. The door lock of claim 13 wherein the interlock comprises mushroom head protrusions on one of said tongue and tail portions for engaging in corresponding slot openings in the other of said tongue and tail portions.
15. The door lock of any preceding c'aim further comprising a dead lock.
16. The door lock of claim 11 wherein the dead lock is operable by means of a key. * * S...S* 5S.*. * . * S. * S S *50 S S..S 5..S *5S*S.....S S