GB2400403A - Lock deadbolt and blocking means for drive arm - Google Patents

Abstract

A lock comprises a casing 10, 11, 12, 13a, 13b, 14 containing a deadbolt 21 moveable between extended and retracted positions by movement of a drive plate 34. The drive plate 34 is operated by the rotation of an external handle through a boss 24a. A key operated internal bolt 100 is moveable to a position in which the internal bolt 100 blocks movement of drive plate 34 and so prevents the deadblot 21 from being extracted.

Description

LOCKS

The invention relates to locks.

According to the invention, there is provided a lock comprising a casing including a member rotatable by operation of a handle, a drive member slidable in the casing to an operative position on rotation of said member in one sense, a deadbolt extendable from the casing on movement of the drive member to said operative position, and an internal bolt movable on operation of a key between a blocking position in which the internal bolt prevents movement of the drive member from the operative position and an unblocking position in which movement of the drive member from the operative position is permitted.

The following is a more detailed description of an embodiment of the invention, by way of example, reference being made to the accompanying drawings in which: Figure 1 is a side elevation of a multi-point lock with a front plate of a casing of the lock removed and with a deadbolt of the lock in a retracted position, Figure 2 is a similar view to Figure 1 but with the deadbolt extended, Figure 3 is a partially exploded view of the multi-point lock of Figures 1 and 2 with the front plate removed, Figures 4A and 4B are respective different perspective views of an auxiliary deadbolt of the multi-point lock of Figures 1 to 3.

Referring to the drawings the multi-point lock is of the same general kind as shown in GB-A-2364545. The multi-point lock comprises a casing formed by an elongate rectangular back plate 10 surrounded by a front wall 11 and a rear wall 12, extending along the longer sides of the back plate 10, and side walls 13a, 13b extending along the shorter sides of the back plate 10. The casing is completed by a front plate 14 (see Figure 3) that sits on a number of upstanding pillars 15 on the back plate 10 that space the front plate 14 from the back plate 10 and receive fixing screws (not shown) passing through holes 16 in the front plate 14 and received in respective pillars IS. In addition, the front plate 14 has two edge flanges 17 that, when the front plate 14 is carried on the pillars 15, project behind the front wall 11 and include holes 18 in register with holes 19 in the front wall 11 to receive fixing screws (not shown) passing through the front wall holes 19.

The casing mounts a latch bolt 20 and a deadbolt 21, which will be described in more detail below. It also mounts a mechanism for extending and retracting two drive rods (not shown) at respective opposite ends of the casing to operate locking members (not shown) at positions remote from the casing.

These locking members are able to be operated, in one mode (to be described below), by rotation of one or other of two handles (not shown) provided on respective opposite sides of the casing. Each handle has an associated separate square section drive rod (not shown) that engages in an associated boss one of which is shown at 24a. Each boss 24a, is mounted between the back plate 10 and the front plate 14 for rotation about an axis normal to the planes of the back and front plates 10, 14. In addition, each boss 24a, includes an arcuate toothed part-pinion (not shown) for engagement with a spring mechanism indicated generally at 27 for provided spring force on the bosses 24a, tending to hold the bosses 24a, in the central position shown in Figures 1 and 2. This spring mechanism 27 is described in GB-A-2364545 and will not be described further here. Each boss 24a, 24b includes a radially projecting follower 28a, 28b for a purpose to be described below.

A return arm 29a, 29b is associated with each boss 24a, 24b. Each return arm 29a, 29b is formed by a generally elongate plate with a widened central portion containing a hole 30a,30b into which fits the associated boss 24a, so that each return arm 29a, 29b is held between the associated boss 24a, and the front plate 14 or the back plate 10 respectively. As seen in Figure 2, each hole 30a, 30b is provided with a notch 31a, 31b which receives a corresponding projection (one of which is seen at 32a in Figures 1 and 2) on the associated boss 24a, 24b to provide a lost motion between each return arm 29a, 29b and the associated boss 24a, 24b.

To one side of the hole 30a, 30b, each return arm is formed with a projecting finger 32a, 32b and, to the other side, with a blocking arm 33a, 33b. As seen in Figures 1 and 2, each blocking arm 33a, 33b has a cranked shape.

The casing also mounts a drive arm on 34 in the form of an elongate plate like member which lies on the back plate 10. The drive arm 34 has a first end adjacently side wall 13a that provides an attachment 22 for connection to a first drive rod (not shown). The drive arm 34 carries, adjacent the first attachment 22 an upstanding plate 40 for a purpose to be described below. The drive arm 34 has a widened central portion immediate at its ends provided with a slot 36 having a central portion 37 extending at an angle of about 45 to the front and rear edges of the back plate 10 and terminating in short end sections 38 that extend parallel to these edges. This slot 36 drives the deadbolt 21 in a manner which will be described below.

Adjacent to the widened portion, the drive arm 34 carries a drive block 39 which receives the ends of the followers 28a, 28b. The end of the drive arm 34 remote from the first attachment 22 carries a first drive rack 42 which faces the front wall 11. A second drive rack 43 faces the first drive rack 42 with a pinion 44 (not shown) acting between the first and second drive racks 42, 43. The effect of this is that sliding movement of the drive arm 34 in one direction is reversed by the pinion to result in corresponding movement of the second drive rack 43 in an opposite direction. The second drive rack carries the second attachment 23 for connection to a second drive arm (not shown).

The deadbolt 21 is formed by a generally rectangular-section block of metal aligned with a square aperture 45 on the front wall and moveable in a linear direction between a retracted unlocked position (shown in Figure 1) in which the deadbolt 21 lies within the casing and an extended locking position (shown in Figure 2) in which the deadbolt projects from the casing through the aperture 45. As described above, the deadbolt 21 is driven by the drive arm 34 through a pin (not shown) on the deadbolt 21 engaging in a slot 36 in the drive arm 34 so that movement of the drive arm 34 in an upward direction (as seen in the Figures) retracts the deadbolt 21 and movement of the drive arm 34 in a downward direction (as viewed in the Figures) extends the deadbolt 21.

A latch bolt 20 is formed by a head 49 and a lath 50. The head 49 is of conventional asymmetric shape with a planar face and an arcuate face meeting at an end edge. The lath 50 is provided with lugs one of which is shown at 103 that engage in respective slots one of which is shown at 70a, in the front plate 14 and the back plate 15 so that the latch bolt 20 is constrained to move in a linear path between a retracted unlocked position in which the latch bolt 20 lies within the casing and the extended locking position in which the latch bolt extends from the casing through a gap in the front wall. The fingers 32a, 32b of the return arm 29a, 29b overlie respective opposite sides of the lathe 50 for engagement with the lug 103. A latch bolt coil spring 71 acts between the rear wall 12 and the latch bolt 20 to tend to urge the latch bolt 20 to the extended locking position.

The casing contains an auxiliary internal deadbolt 100 best seen in Figures 4a and 4b. The auxiliary deadbolt 100 comprises a generally rectangular cross section head 101 attached to a lath 102 that has a square cross section pin 104 projecting from one surface and two guide blocks 105a, 105b extending from the other surface. The guide block 105a, 105b are received in respective slots 106a, 106b in the back plate 10 that constrain the auxiliary deadbolt 10 to rectilinear sliding movement in a direction normal to the front and rear walls s 11, 12 and parallel to the direction of movement of the deadbolt 21. The head 101 also includes a guide pin 107 that is received in a slot 108 in the front plate 14 so also assisting in the guidance ofthe auxiliary deadbolt 100.

A plurality of levers l O9a, lO9b are also mounting in the casing with each lever lO9a, lO9b being of conventional type in the form of a plate provided at one end with a hole 110 that allows the lever lO9a, lO9b to be mounted on a rod 111 (not shown) projecting from the from the back plate 10 so that the levers lO9a, lO9b are pivotable about an axis parallel to the axis of rotation of the boss 24a, 24b. Each lever lO9a, lO9b includes an aperture 112a 112b having inner and outer arcuate walls interconnected by first and second radial walls. A blocking projection projects from each first radial wall and a blocking projection extends from each second radial wall. As seen in Figures 1 and 2, the square section pin 104 on the lathe 102 of the auxiliary deadbolt 100 extends through the registering apertures 112a, 112b to control the movement of the auxiliary deadbolt 100 in a manner to be described below.

Although two levers lO9a, lO9b are shown, there could be more levers if required.

The back plate 10 and the front plate 14 are provided with registering keyholes ll9a, ll9b. A keycam 120 extends between the keyholes ll9a, ll9b and comprises a central tubular portion 121 surrounded at one end by a disc shaped portion 122. The diameter of the tubular portion 121 is similar to the diameter of the part circular portions of the keyholes l 19a, l l9b and the disc shaped portion 122 includes an elongated slot 123 of similar shape to the slots in the keyholes 119a, l l9b. The tubular portion 121 has a longitudinal slot in line with the slot 123 in the discshaped portion 122. The keycam 120 is mounted for rotation about an axis coaxial with the bosses 24a, 24b. In addition, as seen in Figures 1 and 2, there is a rest position of the keycam 120 where the keycam slot 123 is in register with the keyholes l 19a, 119b. A spring 125 bears against a flattened portion 126 of the disc-shaped portion 122 to tend to hold the keycam 20 in the position shown in Figures 1 and 2.

In use the lock operates as follows.

The lock is mounted on a long face plate (not shown) which, in turn, is mounted in an edge surface of a door opposite the hinged edge. The long face plate is flush with the surface and the appropriate keepers are provided on the adjacent edge of the associated frame. The first and second attachments 22, 23 are connected to respective first and second drive members that connect All- respective locking mechanisms at the top and bottom ends of the door which include bolts moveable by operation of the drive members between unlocked and locking positions. These drive members are covered by the long face plate.

Two handles are provided, one on each side of the door with each handle having an associated square cross section drive rod that engages in a respective boss 24a, 24b. As described in GB-A-2364545, the lock can be adapted to be used on doors that open either into a room or out of a room or that have the hinges on the left hand side or the right hand side of the door.

If the handle outside the room (i.e. the handle associated with the back plate 10) is rotated downwardly, the associated boss 24b will rotate causing the associated projection 32b on the boss 24b to engage the end of the notch 3 lb in the associated return arm 29b and pick up the associated return arm 29b for rotation with the boss 24b. Since, however, the finger 32b on the return arm 29b does not engage the latch bolt 20, this movement will not retract the latch bolt 20 and so the door will remain latched. Raising the exterior handle will rotate the associated boss 24b in the opposite direction but, as a result of lost motion between the notch 31b and the associated projection 32b on the boss 24b, the return arm 29b will not rotate. However, the associated follower 28b will rotate, and acting on the drive block 39, will move the drive arm 34 downwardly as viewed in Figure l to extend the first and second drive members as described above, and so move the remote bolts to their lock position. At the same time, the pin on the deadbolt 21 leaves one end section 38 of the slot 36 of the drive arm 34 and passes along the central section 37 (now shown) to cause the deadbolt to move from the retracted unlock position shown in Figure 1 to an extended locked position as shown in Figure 2 where it engages a keeper on the frame. As mentioned above, the deadbolt 21 is constrained to linear movement by engagement of the lug 46 in the slot 47 on the front plate 14. Accordingly, the door can not be unlatched from the exterior and lifting the handle simply increases security by throwing the remote bolts from the deadbolt.

Rotating the interior handle downwardly rotates the associated boss 24a eventually causing the associated projection 32a to engage the end of the associated notch 31a in the return arm 29a so rotating the return arm 29a clockwise as viewed in Figure 1. Since the finger 32a on the return arm 29a engages the lug 103 on the latch bolt 20, this retracts the latch bolt 20 against the action of the coil spring 71, so allowing the door to be opened. Release of the handle causes the coil spring 71 to move the latch bolt 20 from the retracted unlocked position to the extended lock position as shown in Figure 1.

If the interior handle is lifted, the associated boss 24a rotates in an anti clockwise direction as shown in Figure 1 and lost motion between the projection 32a and the notch 31a ensures that this does not cause rotation of the associated return arm 29a. This movement does, however, move the associated follower 28a which moves the drive arm 34 downwardly as viewed in Figure 1.

As a result, the first and second drive members are extended from the casing as described above to move the remote bolt to their locking position. At the same time, the pin on the deadbolt 21 leaves one end section 38 of the slot 36 on the drive arm 34 and passes along the central section 37 to cause the deadbolt 21 to move from the retracted unlocked position shown in Figure 1 to the extended lock position shown in Figure 2 where it engages a keeper on the frame.

If, in this position, a key is inserted into either keyhole ll9a or ll9b and rotated, the keycam 120 rotates and the key lifts the levers 109a, 109b in conventional fashion before engaging the auxiliary deadbolt 100 to move it from the inoperative position shown in Figure 1 to the operative position shown in Figure 2. During such movement, the pin 104 passes through the gap between the blocking lugs. As the key disengages from the levers 109a, 109b, they drop to engage the pin 104 in the gap between the locking lugs and the outer arcuate walls as seen in Figure 2. This prevents the auxiliary deadbolt 100 being forcibly retracted.

When so extended, the auxiliary deadbolt 100 overlies the plate 40 on the drive arm 34 as shown in Figure 2. This thus prevents the drive arm 34 being moved from the position shown in Figure 2, where the deadbolt 21 and the remote bolts (not shown) are in a locking position, to unlocked positions.

The lock can be unlocked by reverse rotation of the key to lift the levers 109a, 109b and retract the auxiliary deadbolt 100. Once this has been done, the handle can be depressed to lift the drive cam 34 and so retract the deadbolt 21 and the remote bolts.

Locks of the general kind described above with reference to the drawings typically use a euro cylinder lock to lock the mechanism and provide a key recognition system. Such euro cylinder locks include a cylinder which projects from the ends of the casing. When too much of the cylinder is exposed, it is possible to break and remove the cylinder from the lock and open the door.

Claims (5)

1. A lock comprising a casing including a member rotatable by operation of a handle, a drive member slidable in the casing to an operative position on rotation of said member in one sense, a deadbolt extendable from the casing on movement of the drive member to said operative position, and an internal bolt moveable on operation of a key between a blocking position in which the internal bolt prevents movement of the drive member from the operative position and an unblocking position in which movement of the drive member from the operative position is permitted.

2. A lock according to claim 1 wherein the drive member includes a stop, the stop moving as the drive member moves to the operative position, from a first position to one side of the path of the internal bolt to the operative position to a second position on the other side of said path, the internal bolt is the operative position preventing the stop moving from said first position to said second position.

3. A lock according to claim l or claim 2 and including at least one lever, said lever normally holding the internal bolt in the operative position but being raised on operation of the key to permit movement of the internal bolt by the key to the operative position.

4. A lock according to claim 3 where said lever holds the internal bolt in the operative position. Operation of the key raising the lever to permit movement of the internal bolt by the key to the inoperative position.

5. A lock substantially as hereinbefore described with reference to the accompanying drawings.