GB1583079A

GB1583079A - Lock

Info

Publication number: GB1583079A
Application number: GB32662/77A
Authority: GB
Original assignee: GKN Stenman AB
Current assignee: GKN Stenman AB
Priority date: 1976-08-16
Filing date: 1977-08-04
Publication date: 1981-01-21
Also published as: NO143283B; DK141973C; NO143283C; SE7609137L; DK141973B; NO772754L; SE401230B; FI74514C; FI74514B; DK362777A; FI772431A

Description

(54) IMPROVEMENTS IN OR RELATING TO A LOCK (71) We, GKN-STENMAN AB, a Swedish Company of Box 343, 631 05 Eskilstuna, Sweden, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to beparticu- larly described in and by the following statement:- The present invention relates to a lock and more particularly the present invention relates to a method of indicating whether a door lock has been locked from one predetermined side of the door.

The requirement of indicating whether a door has been locked from one predetermined side is found, for example, in hotels, - where hotel staff often need to know whether a hotel guest is in his room or not.

Various arrangements have been proposed previously some of which operate electrically, for indicating whether a lock has been locked from one side or the other of a door. Sensors associated with one such prior proposed arrangements are arranged within the lock housing directly to register whether the key is operated from one or the other side. However, the prior proposed arrangements are rather complicated and not reliable.

According to one aspect of this invention there is provided a method of indicating whether a door lock has been locked from one predetermined side of the - door wherein when locking from a first side of the door the latch bolt of the lock is prevented from moving its full locking stroke by means of a latching device, while when locking from the second side said latching device is moved to a release position so that the latch bolt, when the lock is being locked, is able to move its full locking stroke, said method comprising sensing the position of either the latch belt or the latching device, and whenl a predetermined position is sensed, indicating that the door has been locked from said predetermined side.

According to another aspect of this invention there is a door lock provided with means for indicating whether the lock has been locked from one predetermined side thereof, said door lock comprising a lock housing having a latch: bolt and a separate operating- means arranged on each side of the lock housing for operating said latch bolt wherein a latching device co-operating with said latch bolt and engages said latch bolt so that when the door is locked from one side the latch bolt is prevented from moving its full locking stroke; and wherein a release means co-operating with the latching device so that, when the lock is being locked from the other side, the release means moves the latching device to a release position in which the latch bolt is permitted to move its full locking stroke; said lock also comprising a sensor adapted to sense when the lock is in a locked condition, whether either the latch bolt or the latching device is in a predetermined posi tion indicative of the fact that the door has been locked from said predetermined side thereof, said sensor being connected to said indicating means to provide an indicating when the door has been - locked from said predetermined side.

In a preferred embodiment of the invention the latching device may have a com paratively -simple form and may be arranged in.the lock house in a manner-conforming to the arrangement of the- remaining lock components therein. The sensor can be positioned in the lock housing and may be actuated by the latching device or may be located in the recess in the door frame engaged by the latch bolt of the lock to be actuated by the latch bolt when performing its full stroke. In the latter case the electrical wires from the sensor are not damaged as a result - of metal fatigue due to repeated openin and closing of the door since the wires may be securely embedded in the door frame.

The fact that the latch bolt, when the door is locked from one side, will not move to its fullest.extent does not represent any serious disadvantage, since the distance through which the latch bolt is permitted to move by the latching device is fully sufficient to secure the door. For example, the full stroke of the latch bolt may be a distance of 20 mm, while the limited stroke of the latch bolt may be approximately 16 mm. This difference of 4 mm is fully sufficient to permit the actuation of a sensor, such as a switch co-operating with an indicating device, without jeopardizing the intruder-security of the lock.

Preferably the latching device is moved to the release position with the aid of a pivotable member.

This pivotable member may be activated, for example, by a lock cylinder associated with the lock or an extension mounted on said lock cylinder, preferably by engage ment in a recess portion of the lock cylinder or the extension thereof, the pivotable member being caused to pivot such that said pivot movement is transmitted to the latching device via a shaft arranged in the lock housing and -carrying the pivotable member.

Because of the provision of a pivotable member outside the lock housing for generating the movement by which the latching device is moved to the release position, there is no need to complicate the lay-out or design of the lock internally or to make additions to the lock housing itself. Thus, the cylindrical plugs of the lock cylinder or the extension thereof themselves contribute to producing a pivot movement, which is transmitted to the latching device arranged wiíhin the lock housing so that said latching device is freed.

In this respect it is preferred that the pivot movement is transmitted to the latching device via a follower arranged on the shaft and engaging the latching device so as to pivot said latching device to a release position against the action of a spring.

In order that the invention may be more readily understood and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a side view of a door lock in accordance with the invention, one side of the lock housing being removed, and the latching device is shown in its non-release position; Figure 2 is - a view corresponding to Figure 1 with the latching device pivotted to a release position; and Figure 3 shows the upper portion of the lock housing shown in Figures 1 and 2, the lock mechanism in the lock housing being operated by a lock cylinder or some other operating device from either side.

A door lock 1 comprises a lock housing 2 provided with a face plate 2a. The hous ing 2 is intended to be located in a suitable recess in a door with the face plate 2a exposed at the side edge of the door. A latch bolt 3 is shown protruding through an aperture in the face plate to engage with a recess in the door frame The latch bolt is operated in a conventional manner by means of a cylinder follower 4 having a toothed segment 4a arranged to co-operate with a further toothed segment 5a and a dogging arm 6.

The latch bolt 3 has a shoulder 3a against which there abuts an abutment portion 8a of a latching device 8 arranged to pivot around a shaft 9 against the action of a spring 10.

Figure 1 illustrates how the latching device 8 is prevented from moving through its full locking stroke when the lock is locked from one side, for example the inside of the door to which the lock is fitted. Thus, as will be seen from the Figure, the latch bolt 3 ,moves through a shorter distance than that corresponding to a full locking stroke.

Figure 2 illustrates how, when the lock is locked from the other side of the door, i.e. the outside of the door, the latching device 8 is pivoted to a release position by the lock cylinder 15 shown to.the left of Figure 3, in which position the latch bolt is permitted to move its full locking stroke, e.g. 20 mm. In this case the latch actuates a sensor 26 arranged in the recess 25 in the door frame, which recess is drawn with dash-dotted lines in Figures 1 and 2. Alternatively the latch means 8 when pivoted may actuated a sensor 26' in the upper portion of the lock housing.

The latching device 8 is pivoted to its release position under the action of a follower element 11 mounted on a shaft- 12.

The shaft 12 extends out of the lock hous lag and .carries on the outside thereof (Figure 3) a pivotable member in the form of an arm 13 which engages a recess portion 16a in an extension 16 carried by the lock cylinder 15.

When the cylinder plug 15a is turned by means of a key the arm 13, as a result of its engagement with the recess portion 16a of the extension 16, the arm 13 will carry out a pivoting movement which is transmitted, via the shaft 12 and the follower element 11, to the latching device 8 causing said latching device to move to the release position shown in Figure 2.

In Figure 3 the reference 20 indicates a lock cylinder which, in addition to a key 21, is also operated by a knob 22. The reference 23 indicates a cover or mounting plate. The lock is provided with an indicator 27 which shows, on an indicator plate 28, whether the lock has been locked from the outside.

The latch bolt can be prevented from moving its full locking stroke in ways other than those shown. The described method in which a pivotable member is arranged outside the locking housing and directly engages a recess in the lock cylinder or an extension thereof is, however, the one preferred in practice.

The switch 26 arranged in the recess 25 may be replaced by any other type of sensor arranged to sense the position.of the latch belt when the door is locked. Similarly, more than one sensor may be arranged in the recess 25 .each adapted to determine whether the bolt is in a respective predetermined position. Further, the follower 11 may actuate a sensor in the lock housing instead of the latching device 8.

WHAT WE CLAIM IS: 1. A method of indicating whether a door lock has been locked from one predetermined side of the door wherein when locking from a first side of the door the latch bolt of the lock is prevented from moving its full locking stroke by means of a latching device, while when locking from the second side said latching device is moved to a release position so that the latch bolt, when the lock is being locked, is able to move its full locking stroke, said method comprising sensing the position of either the latch bolt or the latching device, and, when a predetermined position is sensed, indicating that the door has been locked from said predetermined side.

2. A method according to claim 1 wherein said sensor is an electric switch.

3. A method according to claim 1 or 2, wherein the latching device is moved to its release position with the aid of a pivotable member.

4. A method according to claim 3, wherein the pivotable member is arranged to be operated by a lock cylinder or an extension thereof associated with the lock, so that said pivotable member is caused in response to movement of the lock cylinder to execute a pivot movement which is transmitted to the latching device via a shaft incorporated in the lock housing and carrying the pivotable member.

5. A method according to claim 4 wherein the pivotable member engages a recessed portion of the lock cylinder or an extension thereof.

6. A method according to claim 5, wherein the pivot movement is transmitted to the latching device via a follower element carried by the shaft, said follower element engaging the latching device so as to pivot the same to its release position against the action of a spring.

7. A door lock provided with means for indicating- whether the lock has been locked from one predetermined side thereof said door lock:comprising a lock housing having a a latch bolt and a separate operating means arranged on each side of the lock housing for operating said latch bolt wherein a latching device co-operates with said latch bolt and engages said latch bolt so that when the door is locked from one side the latch bolt is prevented from. moving its - full locking stroke, and wherein a release means co-operating with the latching device so that, when the lock is being locked from the other side, the release means moves the latching device to a release position in which the latch bolt is permitted - to move its full locking stroke, said lock also comprising a sensor adapted to sense, when the lock is in a locked condition whether either the latch bolt or the latching device is in a predetermined position indicative of the fact that the door has been locked from said predetermined side thereof, said sensor being connected to said indicating means. to provide an indication when the door has been locked from said predetermined side.

8. A lock according to claim 7 wherein the latch bolt is operated by a follower via a transmission device in the form of a toothed segment.

9. A lock according to claim 7 or 8 wherein said operating means comprise lock cylinders.

10. A lock according to claim 7 or 8 or 9 wherein the sensor comprises an electric switch within the lock housing.

11. A lock according to any one of claims 7 to 9 wherein the sensor is located directly to sense the position of the bolt.

12. A lock according to any one of claims 7 to 11 wherein the release means is arranged to co-operate with a member arranged externally of the lock housing and operated by one of said operating means or an extension thereof, by engagement therewith upon turning of the operating means, so as to execute a pivot movement which is transmitted to the release means thereby moving the latching device to its release position.

13. A lock according to claim 12, where in the release means is carried by a shaft which also carries a member arranged externally of the lock housing.

14. A lock according to claim 12, where in the release means is a follower carried by the said shaft.

15. A lock according to any one of claims 7 to 14 wherein the latching device is pivotally mounted in the lock housing

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

in which a pivotable member is arranged outside the locking housing and directly engages a recess in the lock cylinder or an extension thereof is, however, the one preferred in practice.

The switch 26 arranged in the recess 25 may be replaced by any other type of sensor arranged to sense the position.of the latch belt when the door is locked. Similarly, more than one sensor may be arranged in the recess 25 .each adapted to determine whether the bolt is in a respective predetermined position. Further, the follower 11 may actuate a sensor in the lock housing instead of the latching device 8.

WHAT WE CLAIM IS: 1. A method of indicating whether a door lock has been locked from one predetermined side of the door wherein when locking from a first side of the door the latch bolt of the lock is prevented from moving its full locking stroke by means of a latching device, while when locking from the second side said latching device is moved to a release position so that the latch bolt, when the lock is being locked, is able to move its full locking stroke, said method comprising sensing the position of either the latch bolt or the latching device, and, when a predetermined position is sensed, indicating that the door has been locked from said predetermined side.
2. A method according to claim 1 wherein said sensor is an electric switch.
3. A method according to claim 1 or 2, wherein the latching device is moved to its release position with the aid of a pivotable member.
4. A method according to claim 3, wherein the pivotable member is arranged to be operated by a lock cylinder or an extension thereof associated with the lock, so that said pivotable member is caused in response to movement of the lock cylinder to execute a pivot movement which is transmitted to the latching device via a shaft incorporated in the lock housing and carrying the pivotable member.
5. A method according to claim 4 wherein the pivotable member engages a recessed portion of the lock cylinder or an extension thereof.
6. A method according to claim 5, wherein the pivot movement is transmitted to the latching device via a follower element carried by the shaft, said follower element engaging the latching device so as to pivot the same to its release position against the action of a spring.
7. A door lock provided with means for indicating- whether the lock has been locked from one predetermined side thereof said door lock:comprising a lock housing having a a latch bolt and a separate operating means arranged on each side of the lock housing for operating said latch bolt wherein a latching device co-operates with said latch bolt and engages said latch bolt so that when the door is locked from one side the latch bolt is prevented from. moving its - full locking stroke, and wherein a release means co-operating with the latching device so that, when the lock is being locked from the other side, the release means moves the latching device to a release position in which the latch bolt is permitted - to move its full locking stroke, said lock also comprising a sensor adapted to sense, when the lock is in a locked condition whether either the latch bolt or the latching device is in a predetermined position indicative of the fact that the door has been locked from said predetermined side thereof, said sensor being connected to said indicating means. to provide an indication when the door has been locked from said predetermined side.
8. A lock according to claim 7 wherein the latch bolt is operated by a follower via a transmission device in the form of a toothed segment.
9. A lock according to claim 7 or 8 wherein said operating means comprise lock cylinders.
10. A lock according to claim 7 or 8 or 9 wherein the sensor comprises an electric switch within the lock housing.
11. A lock according to any one of claims 7 to 9 wherein the sensor is located directly to sense the position of the bolt.
12. A lock according to any one of claims 7 to 11 wherein the release means is arranged to co-operate with a member arranged externally of the lock housing and operated by one of said operating means or an extension thereof, by engagement therewith upon turning of the operating means, so as to execute a pivot movement which is transmitted to the release means thereby moving the latching device to its release position.
13. A lock according to claim 12, where in the release means is carried by a shaft which also carries a member arranged externally of the lock housing.
14. A lock according to claim 12, where in the release means is a follower carried by the said shaft.
15. A lock according to any one of claims 7 to 14 wherein the latching device is pivotally mounted in the lock housing

and is moved to its release position against the action of a spring.
16. A door lock according to any one of claims 7 to l5 wherein the latch bolt has a shoulder against which the latching device bears.
17. A method substantially as herein described with reference to the accompanying drawings.
18. A door lock substantially as herein described with reference to, and as shown in, the accompanying drawings.