GB1587744A - Lock mechanisms - Google Patents

Description

(54) IMPROVEMENTS IN OR RELATING TO LOCK MECHANISM (71) We, PICKERSGILL-KAYE LIMITED, a British Company, of 84 South Accommodation Road, Hunslet, Leeds LS10 lPU, 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 be particularly described in and by the following statement: This invention relates to lock mechanisms for doors and more particularly the invention relates to a door lock of the kind having a bolt which is normally releasable from a locking position by means of a key and which is releasable in an emergency without the key by means of a manually-operable lever.

According to the present invention there is provided a lock mechanism comprising: a casing provided with a bolt slidable between a locked position and an unlocked position, an actuating member for sliding the bolt being pivotably mounted on the bolt and biased towards a normal position in which the actuating member engages with a slide member which is slidably movable by means of a key so as to move the bolt by means of the actuating member between the locked position and the unlocked position; and a manually operable lever for unlocking the lock mechanism in an emergency without the use of the key, the lever being disposed such that, when the lever is moved from a normal position to a release position, an arm engages with the actuating member and pivots the actuating member out of engagement with the slide member and thereafter engages with the bolt so as to move the bolt from the locked position to the unlocked position, the lock mechanism including means for indicating when the manually operable lever has been used.

The means for indicating when the manually operable lever has been used may comprise a panel of glass which is broken upon movement of the lever from the normal position to the release position. The lock mechanism may include a push pad formed on the manually operable lever. The lock mechanism may include a spring for biasing the lever to its normal position.

For a better understanding of the present invention and to show more clearly how it may be carried into effect reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is an elevational view of a lock mechanism; and Figure 2 is a plan view of part of the lock mechanism shown in Figure 1 showing a lever for releasing the lock in an emergency.

Figure 1 shows a lock mechanism which comprises a casing 1 within which a bolt 2 is slidably mounted. The bolt is formed with an extension 3 and is slidable between an unlocked position in which the extension 3 is within the casing and a locked position in which the extension 3 is outside the casing as shown in Figure 1.

An actuating member in the form of an actuating plate 4 is pivotably mounted on the bolt 2 and is formed with a projection 5 which, in the normal position of the plate 4 shown in Figure 1, engages with a recess 6 formed in a slide member in the form of a slidable plate 7. Plate 4 is maintained in engagement with plate 7 by means of a spring 8 secured to the plate 4 and abutting against the casing 1.

Plate 7 is movable in a direction parallel to bolt 2. A latch 9 is pivotably mounted on the plate 7 and is formed with a recess 10 which is engageable with a pin 11 secured to the casing 1. When the recess 10 is engaged with the pin 11 the bolt 2 and plates 4 and 7 are prevented from being moved. Latch 9 is urged downwardly by means of a spring 12.

A projection 13 formed on a key-operated cylinder lock 14 is engageable with the bottom edge of latch 9. On insertion of the required key, projection 13 may be rotated in a clockwise direction thereby lifting the latch 9 and disengaging the latch from pin 11. Projection 13 then engages with a recess 15 formed in plate 7 and moves the plate towards the right as seen in Figure 1 there by moving plate 4 and bolt 2 in the rightward direction and so unlocking the lock.

As projection 13 is rotated further in the clockwise direction, latch 9 is lowered and engages with a further recess thereof with the pin 11 thereby retaining the bolt 2 in the unlocked position.

The lock is re-locked by rotating the key and thus the projection 13 in the anficlockwise direction, the operations being the reverse of those when the lock is unlocked.

Figure 2 shows an assembly for releasing the lock in an emergency. The assembly comprises a housing 20 which is formed with an aperture, the aperture being closed by a glass panel 21. Mounted in the housing behind the glass panel is a lever 22 pivotably mounted on a pin 23. The lever 22 is formed with two arms 24 and 25. Arm 24 is provided with a stud 26 which is normally positioned immediately behind the glass panel 21. A further lever 27 having a push pad arranged on one end thereof extends out of the housing and engages with arm 24 so that, when push pad of lever 27 is pushed, the glass panel is broken and arms 24 and 25 are pivoted in an anti-clockwise direction as shown in Figure 2. A spring 28 is positioned between the housing 20 and arm 25 to urge the arm in the clockwise direction.

Thus, even if the glass panel 21 is broken, the lock may be temporarily reset until a fresh panel 21 can be inserted.

Arm 25 is positioned so that it extends through an aperture 16 in the bolt 2 (see Figure 1), arm 25 being shown in section in Figure 1. As arm 25 is pivoted in the anticlockwise direction as a result of the push pad of lever 27 being pushed, arm 25 is moved in the rightward direction as seen in Figure 1 and engages with an inclined edge 17 formed on the plate 4. The engagement with the edge 17 causes the plate 4 to pivot in the anti-clockwise direction and disengages the projection 5 from the plate 7. As arm 25 is moved further in the rightward direction, the arm engages with the right-hand edge of the aperture 16 and moves bolt 2 rightwards thereby unlocking the lock. The broken glass panel 21 indicates that the lock has been unlocked without the use of a key.

Projection 5 can be re-engaged with plate 7 by rotating projection 13 of the cylinder lock 14 in the clockwise direction.

The assembly shown in Figure 3 may be mounted, for example, on the internal side of an exterior door of a building or on both sides of an interior door which is normally kept locked. As an alternative, or in addition, to lever 27, crush bars fitted to a door may be linked to arm 24.

Whilst the broken glass panel 21 is a convenient indication that the lock has been unlocked without the use of a key, it is possible to substitute other means of indicating that lever 27 has been used.

WHAT WE CLAIM IS: 1. A lock mechanism comprising: a casing provided with a bolt slidable between a locked position and an unlocked position, an actuating member for sliding the bolt being pivotably mounted on the bolt and biased towards a normal position in which the actuating member engages with a slide member which is slidably movable by means of a key so as to move the bolt by means of the actuating member between the locked position and the unlocked position; and a manually operable lever for unlocking the lock mechanism in an emergency without the use of the key, the lever being disposed such that, when the lever is moved from a normal position to a release position, an arm engages with the actuating member and pivots the actuating member out of engagement with the slide member and thereafter engages with the bolt so as to move the bolt from the locked position to the unlocked position, the lock mechanism including means for indicating when the manually operable lever has been used.

2. A lock mechanism as claimed in claim 1, wherein the means for indicating when the manually operable lever has been used comprises a panel of glass which is broken upon movement of the lever from the normal position to the release position.

3. A lock mechanism as claimed in claim 1 or 2, and including a push pad formed on the manually operable lever.

4. A lock mechanism as claimed in claim 1, 2 or 3, and including a spring for biasing the lever to its normal position.

5. A lock mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying draw ings.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. by moving plate 4 and bolt 2 in the rightward direction and so unlocking the lock. As projection 13 is rotated further in the clockwise direction, latch 9 is lowered and engages with a further recess thereof with the pin 11 thereby retaining the bolt 2 in the unlocked position. The lock is re-locked by rotating the key and thus the projection 13 in the anficlockwise direction, the operations being the reverse of those when the lock is unlocked. Figure 2 shows an assembly for releasing the lock in an emergency. The assembly comprises a housing 20 which is formed with an aperture, the aperture being closed by a glass panel 21. Mounted in the housing behind the glass panel is a lever 22 pivotably mounted on a pin 23. The lever 22 is formed with two arms 24 and 25. Arm 24 is provided with a stud 26 which is normally positioned immediately behind the glass panel 21. A further lever 27 having a push pad arranged on one end thereof extends out of the housing and engages with arm 24 so that, when push pad of lever 27 is pushed, the glass panel is broken and arms 24 and 25 are pivoted in an anti-clockwise direction as shown in Figure 2. A spring 28 is positioned between the housing 20 and arm 25 to urge the arm in the clockwise direction. Thus, even if the glass panel 21 is broken, the lock may be temporarily reset until a fresh panel 21 can be inserted. Arm 25 is positioned so that it extends through an aperture 16 in the bolt 2 (see Figure 1), arm 25 being shown in section in Figure 1. As arm 25 is pivoted in the anticlockwise direction as a result of the push pad of lever 27 being pushed, arm 25 is moved in the rightward direction as seen in Figure 1 and engages with an inclined edge 17 formed on the plate 4. The engagement with the edge 17 causes the plate 4 to pivot in the anti-clockwise direction and disengages the projection 5 from the plate 7. As arm 25 is moved further in the rightward direction, the arm engages with the right-hand edge of the aperture 16 and moves bolt 2 rightwards thereby unlocking the lock. The broken glass panel 21 indicates that the lock has been unlocked without the use of a key. Projection 5 can be re-engaged with plate 7 by rotating projection 13 of the cylinder lock 14 in the clockwise direction. The assembly shown in Figure 3 may be mounted, for example, on the internal side of an exterior door of a building or on both sides of an interior door which is normally kept locked. As an alternative, or in addition, to lever 27, crush bars fitted to a door may be linked to arm 24. Whilst the broken glass panel 21 is a convenient indication that the lock has been unlocked without the use of a key, it is possible to substitute other means of indicating that lever 27 has been used. WHAT WE CLAIM IS:

1. A lock mechanism comprising: a casing provided with a bolt slidable between a locked position and an unlocked position, an actuating member for sliding the bolt being pivotably mounted on the bolt and biased towards a normal position in which the actuating member engages with a slide member which is slidably movable by means of a key so as to move the bolt by means of the actuating member between the locked position and the unlocked position; and a manually operable lever for unlocking the lock mechanism in an emergency without the use of the key, the lever being disposed such that, when the lever is moved from a normal position to a release position, an arm engages with the actuating member and pivots the actuating member out of engagement with the slide member and thereafter engages with the bolt so as to move the bolt from the locked position to the unlocked position, the lock mechanism including means for indicating when the manually operable lever has been used.

2. A lock mechanism as claimed in claim 1, wherein the means for indicating when the manually operable lever has been used comprises a panel of glass which is broken upon movement of the lever from the normal position to the release position.

3. A lock mechanism as claimed in claim 1 or 2, and including a push pad formed on the manually operable lever.

4. A lock mechanism as claimed in claim 1, 2 or 3, and including a spring for biasing the lever to its normal position.

5. A lock mechanism substantially as hereinbefore described with reference to, and as shown in, the accompanying draw ings.