GB2349415A

GB2349415A - Key-operated deadbolt

Info

Publication number: GB2349415A
Application number: GB0002732A
Authority: GB
Inventors: Clive Betts; Tim Henson
Original assignee: WALSALL LOCKS Ltd
Current assignee: WALSALL LOCKS Ltd
Priority date: 1999-02-10
Filing date: 2000-02-08
Publication date: 2000-11-01
Also published as: GB0002732D0; GB9902842D0

Abstract

A key-operated deadbolt mechanism 10 comprises a bolt 12 having an advanced position (shown) and a retracted position. Pivotally mounted bolt throwing means 14 engage the bolt by turning as the key is turned, to move the bolt between the advanced and retracted positions. The bolt thrower 14 has at least two throwing members 16, 18 which turn into and out of engagement with the bolt at different stages of the movement of the thrower 14, which increases the range of angles through which the bolt thrower can engage the bolt, thus increasing the bolt throw obtainable.

Description

Lock The present invention relates to locks and in particular, to key-operated deadbolt locks.

Deadbolt mechanisms are conventionally used as mortice locks, fitted into the jamb of a door, for instance. In order to allow ease of fitting and replacement, various standard dimensions have become adopted as conventional, such as the outer dimensions of the casing, and the position of the keyhole in the casing of deadlocks, and the relative positions of the keyhole and spindle hole of a sash lock.

These restrictions on dimensions pose a significant difficulty to any attempt to make improvements to the lock mechanism.

The present invention provides a key-operated deadbolt mechanism comprising a bolt movable between an advanced and a retracted position, and pivotally mounted bolt throwing means operable to engage the bolt by turning as the key is turned, thereby to move the bolt between the said positions, wherein the bolt throwing means comprises at least two throwing members which can each turn into and out of engagement with the bolt as the bolt throwing means turns, to move the bolt, and wherein each of the throwing members, in use, engages the bolt while the bolt throwing means is moving through a respective range of positions.

The use of multiple throwing members arranged in this manner increases the range of angles through which the bolt thrower can engage the bolt, thus increasing the bolt throw obtainable.

Preferably, the said ranges of positions are overlapping, whereby a throwing member will remain engaged with the bolt until another throwing member has turned into engagement with the bolt.

Preferably two throwing members are provided. One throwing member may be provided by a sleeve which accommodates the head of the key, in use.

Another throwing member may be provided as a pivotally mounted finger. The throwing members may be mounted to turn together about a common pivot axis. The throwing members may have different radial lengths.

Preferably the bolt has an edge in which at least one recess is formed for receiving a throwing member. Preferably, each throwing member is received in a respective recess.

Alternatively, the said ranges of positions may be non-overlapping, whereby a throwing member will move out of engagement with the bolt before another throwing member has turned into engagement with the bolt.

Embodiments of the present invention will now be described in more detail, by way of example only, and with reference to the accompanying drawings, in which: Fig. 1 is a general schematic view of a lock according to the present invention, indicating its manner of operation with a key of the type shown in Fig. 1A ; Figs. 2a to 2f are partial schematic elevations of the lock of Fig. 1, with some parts removed, showing the lock at various stages of movement during operation; and Fig. 3 is a side elevation of the bolt for use in the lock of Figs. 1 and 2.

Turning to Fig. 1, there is shown a key-operated deadbolt mechanism 10 comprising a bolt 12 movable between an advanced position (shown) and a retracted position (to be described). Pivotally mounted bolt throwing means are provided, indicated generally at 14, operable to engage the bolt by turning as the key is turned, thereby to move the bolt between the said positions. The bolt thrower 14 comprises at least two throwing members 16, 18 which can each turn into and out of engagement with the bolt (as will be described) as the bolt thrower 14 turns, to move the bolt. As will become apparent, each of the throwing members 16,18 will, in use, engage the bolt while the bolt throwing means moves through a respective range of positions.

In more detail, the mechanism 10 is housed within a casing 20, behind a forend plate 22. The bolt can be withdrawn into the casing 20 when the lock is open (Fig. 2a) or can be advanced out of the casing 20, to the locked position (Fig. 2f). Movement is caused by turning the bolt thrower 14 by means of a key, and movement is controlled by means of detainers 24.

The bolt thrower 14 is in the form of a disc 26 mounted to pivot around its centre and carrying the throwing member 16, which is in the form of a sleeve 16 into which the head 30 of a key 32 (Fig. 1A) can be fitted, with the shank 34 of the key extending perpendicular to the disc 26, and with the axes of the disc 26 and shank 34 coincident. Preferably, the disc 26 has a slot to allow a key 32 to be inserted into the sleeve 16 from the other side of the disc 26 to that which carries the sleeve 16, and therefore from either side of the door or other member to which the mechanism 10 is fitted.

When the head 30 is in the sleeve 16, the sleeve 16 and thus the disc 26 will turn about the centre of the disc 26 when the shank 34 is turned about its axis. As this happens, the head 30 will move into contact with the detainers 24.

Each detainer is pivotally mounted in the casing 20 at 36 and is biased by a leaf spring 38 to the position shown in Fig. 1. In this position, a bolt stump 40, attached to the bolt 12, is prevented from moving into a slot 42 in the detainer 24 by a lip 43 unless the detainers 24 are all pivoted at 36 to a position at which the gate 44 of the slot 42 on each detainer 24 aligns with the bolt stump 40, thus allowing the bolt 12 to move into the slot 42 as the bolt 12 withdraws from the advanced position (Fig. 1). The detainers 24 are arranged face-to-face along the pivot 36 and will only come into line in this way if the correct key 32 is used. Similarly, a bolt 12 in the retracted position cannot be advanced to the locked position unless the correct key is used, in order to align the gates 44 to allow the bolt stump 40 to leave the slots 42, to return to the position shown in Fig. 1. Until the detainers are raised to align the gates 44, the lips 43 again prevent the stump 40 from moving.

In addition to receiving the key 32, the sleeve 16 performs the function of engaging the lower edge of the bolt 12 in order to push the bolt between the locked and unlocked positions. The finger 18 has a similar function. Reference to Fig. 2 allows this function and the significance of the two elements to be described in more detail.

Fig. 2 shows the lock arrangement with the detainers 24 removed, for clarity. In Fig. 2a, the lock is in the fully unlocked condition. A key can be inserted into the sleeve 16, allowing the disc 26 to be turned until a point is reached at which the sleeve 16 makes contact with the leading surface 48 of a first notch 50 (Fig. 2b). Further rotation of the disc 26 (anti-clockwise) will cause the bolt 12 to begin moving toward the locked position, but this will be blocked by the detainers 24 unless the correct key has been used, as described above. As the disc 26 continues to turn, an intermediate position is reached (Fig. 2c) at which the sleeve 16 is still in contact with the surface 48, but the finger 18 has now come into contact with the leading edge 52 of a second notch 54. Thus, as the disc 26 continues to turn, both the sleeve 16 and the finger 18 will be pushing the bolt 12.

Eventually, a position is reached at which the sleeve 16 turns out of engagement with the leading surface 48 and is thus not able to push the bolt 12 any further to the locked position. However, the finger 18 is still in engagement with the leading edge 52 at this position, so that the bolt 12 can be further advanced by further rotation of the disc 26.

Eventually, the arrangement reaches a position (Fig. 2e) at which the finger 18 moves out of engagement with the leading edge 52, so that no further bolt movement is created by turning the disc. The bolt 12 is then in the fully advanced (locked) position. The disc 26 can then continue to turn (without further bolt movement) until reaching the starting position after one full turn, allowing the key to be removed to leave the bolt 12 locked. At this position (Fig.

2f) the detainers 24 will have dropped behind the stump 40, locking the bolt in that position.

The lock can be unlocked, by means of the correct key, by reversing the sequence of operations. With the correct key inserted, the disc 26 is turned clockwise until the detainers 24 are engaged, at which point the finger 18 will have just come into engagement with the trailing face 56 of the notch 54. With the gates 44 aligned with the stump 40, further clockwise rotation of the disc 26 causes the finger 18 to push the bolt 12 back from the advanced position to the retracted position, with this initial engagement being solely by way of the finger 18. Eventually, a position is reached at which the sleeve 16 comes into contact with the trailing face of the first notch 50, so that the bolt 12 is then being pushed by the sleeve 16 and also by the finger 18.

As the disc 26 reaches the position of Fig. 2c, the finger 18 moves clear of the trailing face 56, but the sleeve 16 is still in engagement with the trailing face 58, so that the disc 26 can continue to move clockwise to cause further retraction of the bolt 12.

As the sleeve 16 returns the bolt 12 to the unlocked position (Fig. 2b), the sleeve 16 moves out of engagement with the trailing face 58, movement of the bolt 12 ceases, and the disc 26 can then continue to turn clockwise until the sleeve 16 reaches the starting position (Fig. 2b) and the key 32 can be withdrawn. The bolt 12 is then held in the unlocked position, by the detainers 24.

It is an important feature of the invention that the throwing of the bolt 12 is achieved by more than one member (here, the sleeve 16 and the finger 18) which engage the bolt 12 over respective different ranges of positions of the disc 26. That is, while locking the bolt, the sleeve 16 comes into engagement with the bolt 12 before the finger 18 does so, and moves out of engagement before the finger 18 does so. When unlocking the lock, the finger 18 comes into engagement with the bolt 12 before the sleeve 16 does so, and moves out of engagement before the sleeve 16 does so. Consequently, the total range of angles of the disc 26 during which there is engagement between the bolt thrower 14 and the bolt 12 is greater than the range of angles through which there is engagement between the sleeve 16 and the bolt 12, or between the finger 18 and the bolt 12. In consequence, by working one after the other, the sleeve 16 and finger 18 create a greater range of movement ("throw") of the bolt 12 than could be achieved by either alone. This allows a greater bolt throw to be achieved without needing to change the size of the casing 20, or the geometry of the disc axis 26 relative to the position of the bolt 12.

The deadbolt mechanism shown in the drawings is intended for use in place of conventional deadlock and mortice sash lock mechanisms conforming to British Standard 3621, for which a bolt throw of 14mm is normal. By use of the invention, a bolt throw of more than 20mm can be achieved without changing the overall size of the casing 20, or relocating those features (such as keyhole position) which must be retained to allow retro-fitting in place of an existing mechanism.

The form of the bolt 12 is shown in more detail in Fig. 3. The leading edge 60, which will project through the forend plate 22 is largely conventional and may be provided with security devices such as anti-saw rollers. The bolt 12 carries the bolt stump 40, as has been described, and has a slot 64 to slide over a control peg 65 (Figs. 1 and 2) fixed in the casing 20, to help guide the bolt movement. Alternatively, the bolt 12 may carry a control peg which slides in a control slot formed in the casing. The notches 50,54 are formed on the lower edge of the bolt 12, toward the rear of the bolt. The rear edge 62 is also cut away at 66 to accommodate a pivot column for the detainers 24. Consequently, the isthmus 68 represents a potential weakness in the bolt 12, but can be widened and strengthened by repositioning the detainer pivot column further away from the notches 50,54, so that the cut-away 66 is positioned likewise.

Consequential redesign of the detainers would be required.

It will be understood that many variations and modifications can be made to the apparatus described above, without departing from the scope of the present invention. In particular, emphasis has been placed on the overlapping ranges of engagement by the plurality of throwing members. This provides smooth, continuous movement of the bolt 12 as the disc 16 turns.

However, each throwing member could alternatively move into and out of engagement with the bolt before a following member does so, so that the bolt 12 would move in discrete steps. In one example, two throwing members spaced at 180 around the disc 26 are envisaged. However, it is felt that in practice, it will usually be preferable to produce continuous rather than stepped movement.

Many variations to the specific shape, sizes and forms of components can be devised, according to the bolt throw required, materials used and strengths required.

Various materials can be envisaged for the construction of the mechanism. In particular, the bolt may be made of hardened or sintered steel.

The bolt stump can be zinc plated mild steel attached to the bolt. Other components can be made of conventional materials chosen for their strength and wear characteristics.

Whilst endeavouring in the foregoing specification to draw attention to those features of the invention believed to be of particular importance it should be understood that the Applicant claims protection in respect of any patentable feature or combination of features hereinbefore referred to and/or shown in the drawings whether or not particular emphasis has been placed thereon.

Claims

CLAIMS 1. A key-operated deadbolt mechanism comprising a bolt movable between an advanced and a retracted position, and pivotally mounted bolt throwing means operable to engage the bolt by turning as the key is turned, thereby to move the bolt between the said positions, wherein the bolt throwing means comprises at least two throwing members which can each turn into and out of engagement with the bolt as the bolt throwing means turns, to move the bolt, and wherein each of the throwing members, in use, engages the bolt while the bolt throwing means is moving through a respective range of positions.
2. A mechanism according to claim 1, wherein the said ranges of positions are overlapping, whereby a throwing member will remain engaged with the bolt until another throwing member has turned into engagement with the bolt.
3. A mechanism according to claim 1, wherein the said ranges of positions is non-overlapping, whereby a throwing member will move out of engagement with the bolt before another throwing member has turned into engagement with the bolt.
4. A mechanism according to any preceding claim, wherein two throwing members are provided.
5. A mechanism according to any preceding claim, wherein one throwing member is provided by a sleeve which accommodates the head of the key, in use.
6. A mechanism according to any preceding claim, wherein a throwing member is provided as a pivotally mounted finger.
7. A mechanism according to any preceding claim, wherein the throwing members are mounted to turn together about a common pivot axis.
8. A mechanism according to claim 7, wherein the throwing members have different radial lengths.
9. A mechanism according to any preceding claim, wherein the bolt has an edge in which at least one recess is formed for receiving a throwing member.
10. A mechanism according to claim 9, wherein each throwing member is received in a respective recess.
11. A key-operated deadbolt mechanism substantially as described above, with reference to the accompanying drawings.
12. Any novel subject matter or combination including novel subject matter disclosed herein, whether or not within the scope of or relating to the same invention as any of the preceding claims.