WO2004040086A1

WO2004040086A1 - A lock mechanism

Info

Publication number: WO2004040086A1
Application number: PCT/SG2003/000250
Authority: WO
Inventors: Chng Zay Cheng
Original assignee: Ccz International Pte Ltd.
Priority date: 2002-10-30
Filing date: 2003-10-20
Publication date: 2004-05-13
Also published as: CN1732322A; AU2003278674A1; EP1573154A1

Abstract

A lock mechanism 200 adapted to receive a cylinder lock 206 having a rotatable actuating member 218 is disclosed herein. According to the first embodiment, the lock mechanism 200 comprises a bolt 6', an intermediate member 12' arranged to guide the bolt 6'; and a rotatable part annular cylinder follower 214 having a first abutment surface 214a, a second abutment surface 214b and means to actuate the intermediate member 12' in the form of a toothed section 214c. In use, the actuating member 218 is rotated to engage one of the abutment surfaces 214a,214ó to rotate the cylinder follower 214 such that the intermediate member 12' is actuated to guide the bolt 6' rectilinearly corresponding to the rotation of the cylinder follower 214.

Description

A Lock Mechanism

Background and Field of the Invention

This invention relates to a lock mechanism, more particularly but not exclusively, to a lock mechanism for a door.

Locks have been in existence for many years with many different shapes, sizes and applications. A particular type of lock is a lock mechanism for a door which receives a cylinder lock activated by a key or thumb knob. The key or thumb knob is rotated to actuate a bolt which extends in a rectilinear direction to engage a corresponding slot in a door frame to lock or unlock a door.

An operation of one kind of lock mechanism of the prior art will first be described. Such a lock mechanism, for example a mortice lock such as ASSA 565 from ASSA has been in use for over thirty years and is still being used today.

Figure 1 shows a side view of a conventional lock mechanism 1 which is typically housed in a lock case 2. The lock case 2 is secured to a lock post 4 which in turn is fixedly mounted to a door (not shown). The lock case 2 has a front side cover removed to reveal the internal components, an identical back side cover 2a being seen behind the internal components and in this case, the lock mechanism 1 includes a dead bolt 6 and a latch bolt 7. The lock mechanism 1 is arranged to actuate one or both of these bolts 6,7 rectilinearly between a first position (in which the bolts 6,7 is protruding out beyond the lock post 4) and a second position (in which the bolts 6,7 is retracted behind the lock post 4).

The lock case 2 also includes two circular openings 3,5 which are used to receive a cylinder follower 8 and a handle follower 22 (to be described hereinafter) respectively. Figure 1a shows a front view of the first circular opening 3 formed in the front and back 2a cover each of which includes an inwardly projecting circular rim 3a. Between the rims 3a, the cylinder follower 8 is supported and connected to two support rings 10, so that the follower 8 and support rings 10 rotate around the circular rim 3a as a unit.

The cylinder follower 8 is shown in detail in Figure 1 b and includes a figure- eight slot 8a forming a constriction 8b near the centre of the slot 8a and a toothed section 8c. The cylinder follower 8 is sandwiched between the two support rings 10 of which one is shown in Figure 1d. Each support ring 10 is formed from two pieces of metal coupled together as shown in Figure 1c. These support rings 10, with the cylinder follower 8 in between, are then aligned to and supported by the projecting circular rim 3a such that the support rings 10 (and ^' the cylinder follower 8) are rotatable. When assembled as shown in Figure 1 , the cylinder follower 8 is arranged to receive two cylinder locks, one at each side of the door case 2. Each lock has an actuating member which engages the slot 8a. The cylinder lock may be of two types. The first type of cylinder lock comprises a key plug at one end and an actuating member radially mounted at the other end of the key plug. The key plug is then arranged to receive a key which is used to rotate the key plug and also the actuating member. The second type of cylinder lock comprises a thumb-knob and a similar actuating member at the distal end of the thumb knob. Rotating the thumb knob also rotates the actuating member.

When the two cylinder locks are assembled one at each end of the first circular opening 3, the actuating members are used to engage the constriction 8b of the figure-eight slot 8a to twist the cylinder follower 8 into motion so that the toothed section 8c of the cylinder follower 8 actuates an intermediate member 12 to move the dead bolt 6 or the latch bolt 7.

The intermediate member 12 includes a toothed section 12a and is hinged using a pivot pin 14 such that the intermediate member 12 rotates radially about the pivot pin 14. The intermediate member 12 includes a striking surface 12b and a lug 12c positioned in an aperture 6a of the dead bolt 6. A first spring 16 is provided which acts against the lug 12c and a first stop member 17 to guide the displacement of the lug 12c in the aperture 6a.

When the cylinder follower 8 is twisted by the actuating member to rotate in an anti-clockwise direction as indicated by an arrow X, the toothed section 8c of the cylinder follower 8, which is interlocked with the corresponding toothed section 12a of the intermediate member 12, rotates the intermediate member 12 in a clockwise direction. Accordingly, the lug 12c displaces to extend the dead bolt 6 beyond the lock post 34 to a "locked position".

To return the bolt 6 to a lock-release position, the thumb-knob or key plug of the cylinder lock (not shown) is rotated to twists the slot 8a of the cylinder follower 8 such that the cylinder follower 8 rotates in a clockwise direction as indicated by the arrow Y. Similarly, the toothed section 12a of the intermediate member 12 is being acted upon by the rotating toothed section 8c of the cylinder follower 8 such that the toothed section 12a rotates in an anti-clockwise direction. This rotation displaces the lug 12c to actuate the dead bolt 6 such that the bolt 6 retracts to the lock-release position.

The latch bolt 7 includes a rod 7a and an enlarged annular base 7b which is engaged by the handled follower 22 or a transmission member 20. A second spring 24 is provided which lies against the latch bolt 7 and also against a second stop member 26 so that the second spring 24 extends the latch bolt 7 in an outward manner.

The handle follower 22 is fitted into the second circular hole 5 and includes a square cavity 22a arranged to receive a shaft of a handle (not shown). The handle follower 22 further includes an extended arm 22b having a striking shoulder 22c arranged to engage the base 7b of the latch bolt 7. When the handle is rotated (in a clockwise direction in this case), the handle follower 22 rotates in the same direction as the handle which swings the extended arm 22b such that the striking shoulder 22c actuates the base 7b of the latch bolt 7 against the action of a third spring 28 (and also the second spring 24). In this way, the latch bolt 7 is retracted behind the lock post 4 by turning the handle.

When the handle is released, the third spring 28 biases the handle follower 22 against the second stop member 26 to return the latch bolt 7 to the "latched" position.

The latch bolt 7 can also be actuated by the cylinder lock via the transmission member 20 which includes a first abutment shoulder 20a at one end and a second abutment shoulder 20b at the other end. The transmission member 20 is also pivotally mounted at the pivot pin 14. The first abutment shoulder 20a is used to engage the striking surface 12b of the intermediate member 12.

With the dead bolt 6 fully retracted as shown in Figure 1 , turning the thumb- knob or key of the cylinder lock further clockwise rotates the toothed section 12a of the intermediate member 12 in an anti-clockwise direction such that the striking surface 12b of the intermediate member 12 strikes the first abutment shoulder 20a and actuates the transmission member 20. This motion is translated to a rectilinear motion of the second abutment shoulder 20b which actuates the base 7b of the latch bolt 7 in a similar manner as the striking shoulder 22c of the extended arm 22b. The latch bolt 7 thus retracts inside the door case 2. Upon the release of the thumb knob or key, the second spring 24 biases the latch bolt 7 to the latched position again. The lock mechanism 1 has a disadvantage that only a specific type of cylinder lock which provides means to twist the cylinder follower 8 can be used. Figure 1 e shows another example of a cylinder follower 9 of the prior art for use with a latch bolt with a figure-eight slot 9a forming a constriction 9b, the same as constriction 8b. Due to the construction of the cylinder followers 8,9, a further disadvantage is that two separate cylinder locks are required for each side of the lock, adding to expense.

Summary of the Invention

In a first aspect of the invention, there is provided a lock mechanism arranged to receive a cylinder lock having a rotatable actuating member, the lock mechanism comprising a bolt, and a rotatable part annular follower having an abutment surface, the abutment surface being arranged to be struck by the actuating member to rotate the follower, the bolt being coupled to the follower and movable rectilinearly in response to the corresponding rotation of the follower.

An advantage of the described embodiments of the invention is that having a part annular follower allows a different type of cylinder lock to be used with the lock mechanism.

Preferably, the follower includes a further abutment surface, such that these surfaces are arranged to be struck by the actuating member to rotate the follower in respective opposite directions. Preferably, the follower comprises a toothed section.

The lock mechanism may further comprise an intermediate member having a corresponding toothed section arranged to interlock with the toothed section of the follower, and a lug arranged in an aperture in the bolt. In one embodiment, the bolt is a dead bolt. Alternatively, the bolt may be a latch bolt and the lock mechanism further comprises means to bias the latch bolt to a latched position. In the latter case, the follower may comprise an engaging arm and the lock mechanism may further comprise a transmission member having a first abutment shoulder arranged for engagement with the engaging arm, and a second abutment shoulder arranged to move the latch bolt to an unlatched position when the first abutment shoulder is actuated by the engaging arm corresponding to the rotation of the follower.

The lock mechanism may further comprise a latch bolt and means to bias the latch bolt to a latched position. In this case, preferably, the lock mechanism further comprises a transmission member having an abutment shoulder arranged to engage the latch bolt, the corresponding rotation of the follower actuating the abutment shoulder to move the latch bolt to an unlatched position.

The invention also relates to a combination of the lock mechanism according to the first aspect and a lock cylinder. Brief Description of the Drawings

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings in which,

Figure 1 shows a cross-sectional side view of a lock mechanism provided in a lock case according to the prior art;

Figure 1a shows a front view of a circular opening in the lock case of Figure 1 to receive a cylinder lock; Figures 1 b to 1 d show close-up views of a cylinder follower of the prior art used in the lock mechanism of Figure 1 ;

Figure 1e shows another cylinder follower of the prior art used for a different application;

Figure 2 illustrates a perspective view of a lock mechanism having a dead bolt and a latch bolt provided in a lock case according to a first embodiment of the present invention;

Figure 3 illustrates a perspective exploded view of the internal components of the lock mechanism of Figure 2;

Figure 4 is a cross-sectional side view of the lock mechanism of Figure 3 with the internal components in position;

Figure 4a illustrate a close-up view of a section of the lock mechanism of Figure

4;

Figures 4b to 4d illustrate close-up views of a part annular cylinder follower according to the first embodiment; Figures 5 and 6 illustrate the movement of the part annular cylinder follower of

Figure 4d to actuate the dead bolt;

Figure 7 illustrate the movement of the part annular cylinder follower of Figure

4d to actuate the latch bolt; Figure 8 illustrates a perspective view of a lock mechanism having two latch bolts provided in a lock case according to a second embodiment of the present invention;

Figure 9 illustrates a perspective exploded view of the internal components of the lock mechanism of Figure 8; Figure 10 is a cross-sectional side view of the lock mechanism of Figure 9 with the internal components in position;

Figure 10a shows a close-up side view of a part annular cylinder follower according to the second embodiment; and

Figures 11 and 12 illustrate the movement of the part annular cylinder follower of Figure 10a to actuate the two latch bolts.

Detailed Description of the Preferred Embodiments

Figure 2 shows a perspective view of a lock mechanism 200 housed in a lock case 202 according to a first embodiment of the invention. The lock case 202 is formed from a first and a second cover 202a,202b which are held together using screws 202c. The housing 202 is attached to a lock post 204 which is mounted to a door frame using coupling screws 204a. The housing 202 has an opening 203 adapted to receive a cylinder lock in the form of an "Euro" style double cylinder lock 206. The cylinder lock 206 includes, at one end, a key plug 208 arranged to receive a key 210 used to rotate an actuating member 218 (see Figure 3) radially movable in the cylinder lock 206. At the other end of the cylinder lock 206, a thumb knob 212 is provided similarly to actuate the actuating member 218 but without the use of a key 210. Typically, the side with the thumb knob 212 faces inside a house or room whereas the side with the key plug 208 faces outside the house or room.

Figure 3 shows a perspective exploded view of the lock mechanism 200 of Figure 1 with the first and second covers 202a,202b separated to illustrate the internal components. Figure 4 shows a cross-sectional side view of the lock mechanism 200 of the first embodiment and the description below will make reference to both of these figures.

The lock mechanism 200 of the first embodiment comprises a part annular cylinder follower 214 having a first abutment surface 214a and a second abutment surface 214b. The cylinder follower 214 also comprises means to actuate the bolt 6 and in this embodiment the actuating means is in the form of a toothed section 214c similar to the prior art. The cylinder follower 214 is movably mounted in annular grooves 215 formed by an inwardly projecting part circular rim 203a and support elements 203b along the circumference of the opening 203 as shown in Figure 4a. In use, The annular grooves 215 guide the rotation of the cylinder follower 214. Figure 4d and 4c show a plan and a side view of the part annular cylinder follower 214, respectively, without the toothed section 214c. Figure 4b shows a side view of the toothed section 214c adapted to fit into an arch shaped slot 214d of the cylinder follower 214. The toothed section 214c is welded into position.

Similar to the prior art discussed earlier, the lock mechanism 200 comprises a dead bolt 6' and a latch bolt T and corresponding components which are used to actuate the bolts 6',7' to lock or unlock a door to which the lock mechanism 200 is attached. For ease of understanding the differences between the prior art and the first embodiment of the present invention, common components will use the same reference numerals with an apostrophe (this naming convention will also be used for the second embodiment).

The lock mechanism 200 of the first embodiment also comprises the intermediate member 12' which has a toothed section 12a', striking shoulder 12b' and a lug 12c' in an aperture 6a' of the dead bolt 6a'. The latch bolt 7' is similarly actuated by a handle follower 22' adapted to receive a handle (not shown) and a transmission member 20' having a first abutment shoulder 20a and a second abutment shoulder 20b. The operation of these components 6',7',12\ 20', 22' are similar to the prior art.

To operate the lock mechanism 200, the cylinder lock 206 is inserted through the opening 203 of the door case 202 and the cylinder follower 214 as illustrated in Figure 3. The cylinder lock 206 is then held in position with a lock screw 216. Turning the key 210 (or thumb knob 212) in an anti-clockwise or clockwise direction rotates the actuating member 218 of the cylinder lock 206 which engages one of the abutment surfaces 214a, 214b depending on the direction of rotation which also determines whether the dead bolt 6' or the latch bolt 7' is actuated.

Figures 5 and 6 illustrate the different positions of the cylinder follower 214 to actuate the dead bolt 6'. Taking the position of the cylinder follower 214 in Figure 4 as the initial position the dead bolt 6' is in a retracted position as shown. Turning the key plug (using the key 210) anti-clockwise (or clockwise if the thumb-knob is used) rotates the actuating member 218 in the same direction until the actuating member 218 strikes the first abutment surface 214a of the cylinder follower 214.

Further rotation of the actuating member 218 rotates the cylinder follower 214 (as indicated by an arrow X' in Figure 5) such that the toothed section 214c of the cylinder follower 214 actuates the corresponding toothed section 12a' of the intermediate member 12' causing the toothed section 12c' to rotate in the opposite direction. The lug 12c' in the aperture 6a' is then guided by the pin 16' to displace and actuate the dead bolt 6' to an extended or locked position as shown in Figure 5.

To retract the dead bolt 6', the actuating member 218 needs to be rotated in a clockwise direction (as indicated by an arrow Y' in Figure 6) by the key 210 such that the actuating member 218 now strikes the second abutment surface 214b of the cylinder follower 214. Further rotation would actuate the intermediate member 12' in the opposite direction. The lug 12c' in the aperture 6a' of the dead bolt 6 traverses back to the initial position such that the dead bolt 6' is now retracted as shown in Figure 6.

Figure 7 shows the action of the lock mechanism 200 when the cylinder follower 214 is rotated further clockwise from the position shown in Figure 6. With the actuating member 218 striking the second abutment surface 214b, rotation of the cylinder follower 214 further clockwise causes the striking surface 12b' of the intermediate member 12' to strike the first abutment shoulder 20a' of the transmission member 20'. The effect is similar to the prior art in that the base 7b' of the latch bolt T is actuated by the second abutment shoulder 20b' of the transmission member 20' such that the latch bolt T retracts into the door case 202 as shown in Figure 7. The second spring 24' biases the latch bolt T to the latched position when the key 210 is released.

The latch bolt 7' of the first embodiment is also actuated by rotating the handle (not shown) attached to the handle follower 22' and the mechanism for performing this is similar to the prior art as described earlier.

Therefore, using a part annular cylinder follower 214 allows an "Euro" style double cylinder lock 206 to be used whilst maintaining the functions of a conventional lock mechanism.

Figure 8 shows a second embodiment of the invention in which a lock mechanism 300 is used to actuate two latch bolts 302,304 and an auxiliary latch 306. The lock mechanism 300 is also housed in a lock case 308 formed from two covers 308a,308b. The lock case 308 includes a opening 203 which is adapted to receive the "Euro" style double cylinder lock 206 described in the first embodiment and the same reference numerals will be used for this component and the other components that are common to the first embodiment.

Figure 9 shows the covers 308a,308b separated to illustrate an exploded perspective view of the internal components of the lock mechanism 300 according to the second embodiment which comprises a part annular cylinder follower 310 having one abutment surface 310a. The actuating means is in the form of two engaging arms 310c,310d instead of a toothed section. Figure 10a shows a side view of the part annular cylinder follower 310 of the second embodiment with the dotted lines representing the first engaging arm 310c.

Figure 10 illustrates a cross-sectional side view of the lock mechanism 300 of the second embodiment with all the components assembled in positioned. The following description makes reference to Figures 9,10 and 10a.

The first and third latch bolt 302,304 includes a rod 302a, 304a and an enlarged annular base 302b,304b similar in construction as the latch bolt 7 of the first embodiment. These two latched bolts 302,304 are actuated by a transmission lever 312 (Figure 10) which is pivoted at one end by a first pivot element 313. The transmission lever 312 includes a first abutment shoulder 312a which is for engagement with the first engaging arm 310c of the cylinder follower 310, a second abutment shoulder 312b to engage the base of the first latch bolt 302 and a third abutment shoulder 312c to engage an engagement lever 314 to actuate the second latch bolt 304. A first spring 318 is provided which lies against the first latch bolt 302 and also against a side of the lock case 300 to bias the first latch bolt 302 in an outward manner.

It will be apparent from the drawings that the second latch bolt 304 is biased in the same manner as the first embodiment and thus the actuation of the second latch bolt 304 by the handle follower 22' and related parts will not be described in the second embodiment. The description will focus on how the transmission lever 312 actuates the second latch bolt 304.

To actuate the first and second latch bolts 302,304, the key 210 is inserted into the key plug 208 to rotate the actuating member 218 in an anti-clockwise direction. Alternatively, the thumb knob 212 may be used. Figures 11 and 12 illustrate the action of the using the key 210 to actuate the first and second latch bolts 302,304.

When the key 210 is inserted into the key plug 208 and rotated, the actuating member 218 engages the first abutment surface 310a of the part annular cylinder follower 310 and actuates the cylinder follower 310 into motion. Accordingly, one of the engaging arms, in this case the first engaging arm 310c, engages the first abutment shoulder 312a of the transmission lever 312 to push the lever 312 towards the base 302b of the first latch bolt 302 until the second abutment shoulder 312b engages the base 302b to retract the latch bolt 302 as shown in Figure 12. Figure 12 also illustrates the engaging lever 314 being actuated by the third abutment shoulder 312c of the transmission lever 312. The engaging lever 314, which is pivoted about a second pivot element 316, then actuates the base 304b to retract the latch bolt 304 rectilinearly whilst the first latch bolt 302 is being retracted by the second abutment shoulder 312b.

The auxiliary latch bolt 306 includes a catch 306a at one end which is coupled to a slot of a linking member 320. The linking member 320 is in turned biased by a fourth spring 322 and when the auxiliary latch bolt 306 retracts, the linking member 320 retracts correspondingly which actuates a jamming element 311 hinged by a pin 313. The distal end of the linking member 320 is then coupled to the transmission lever 312 such that when the transmission lever 312 is actuated by rotating the actuating member 310, the auxiliary latch bolt 306 also retracts as shown in Figure 12. When the lock mechanism 300 is fitted to a door and when the door is closed, the two latch bolts 302,304 are biased by the two springs 318,319 to their latched positions in corresponding bores along a jamb of a door frame. However, the auxiliary latch bolt 306 does not have a corresponding bore and is held in a retracted position. This means that the linking member 320 is retracted which actuates the jamming element 311 upwards. The jamming 311 element includes a first extended section 311 a arranged to "jam" the base 302b of the first latch bolt 302 which transforms the first latch bolt to function like a "dead bolt". Therefore, when the door is closed, without a key to "release" the jamming element 311 a user is unable to open the door. The jamming element 311 can also be released by turning the thumb knob 212 which has the same effect as releasing the jamming element 311 using a key. When the thumb knob is rotated, the first engagement and second engagement arm 310c,310d are both rotated as described earlier. The first engagement arm 310c performs in a same way but the second engagement arm 31 Od engages a second extended section 311b of the jamming element 311 which pushes the jamming element downwards (as shown in Figure 12). This action disengages the first extended section 311a from the base 302b of the first latch bolt 302 thus "freeing" up the first latch bolt 302 which releases the "jamming" effect.

The lock mechanism 300 of the second embodiment also comprises a quick release lever 321 positioned at the lock post 305. When the first and auxiliary latch bolts 302,306 are retracted, this lever 321 may be adjusted to lock the first latch bolt 302 and auxiliary latch bolt 306 in a retracted position and allowing the second latch bolt to function as per normal and allowing a user to open the door by turning the handle. This lever 321 , can thus be used to activate or deactivate the "dead bolt" function due to the action of the auxiliary latch bolt 306. This also allows the door to be locked without the use of a key, unlike the first embodiment, since if the dead bolt function is activated (by setting the lever 321 to the correct position) the door would be locked automatically whenever the door is closed.

In this way, though the use of a part annular cylinder 310, the lock mechanism

300 of the second embodiment is adapted to receive the "Euro" style double cylinder lock 206 to actuate the latch bolts 302,304. It should be apparent that the invention also allows other types of cylinder locks can be used which provides a similar actuating member to actuate the part annular cylinder follower 310.

The described embodiments should not be construed as limitative. For example, the rotational direction depicted in the described embodiments is with respect to one end of the door case 202,308. If the cylinder lock 206 is actuated using the thumb-knob 212 at the other end of the housing 202,308, the rotation direction would be different.

The lock mechanism 200,300 may also be used for a window and not merely for a door. In this case, the lock mechanism 200,300 may only comprise a dead bolt 6' or a latch bolt 7', and the cylinder lock used to extend the corresponding bolt may thus require either a key plug or a thumb-knob.

The lock mechanism 200,300 may not comprise the intermediate member 12' or the transmission lever 312 particularly if only a dead bolt or latch bolt is present. The part annular cylinder follower 214,310 may actuate the bolt directly to extend or retract the bolt.

Having now fully described the invention, it should be apparent to one of ordinary skill in the art that many modifications can be made hereto without departing from the scope as claimed.

Claims

1. A lock mechanism arranged to receive a cylinder lock having a rotatable actuating member, the lock mechanism comprising a bolt, and a rotatable part annular follower having an abutment surface, the abutment surface being arranged to be struck by the actuating member to rotate the follower, the bolt being coupled to the follower and movable rectilinearly in response to the corresponding rotation of the follower.

2. A lock mechanism according to claim 1 , wherein the follower includes a further abutment surface, the abutment surfaces being arranged to be struck by the actuating member to rotate the follower in respective opposite directions.

3. A lock mechanism according to claim 1 or claim 2, wherein the follower comprises a toothed section.

4. A lock mechanism according to claim 3, further comprising an intermediate member having a corresponding toothed section arranged to interlock with the toothed section of the follower, and a lug arranged in an aperture in the bolt.

5. A lock mechanism according to claim 4, wherein the bolt is a dead bolt.

6. A lock mechanism according to claim 5, further comprising a latch bolt and means to bias the latch bolt to a latched position.

7. A lock mechanism according to claim 6, further comprising a transmission member having an abutment shoulder arranged to engage the latch bolt, the corresponding rotation of the follower actuating the abutment shoulder to move the latch bolt to an unlatched position.

8. A lock mechanism according to claim 1 , wherein the bolt is a latch bolt

and further comprises means to bias the latch bolt to a latched position.

9. A lock mechanism according to claim 8, wherein the follower comprises an engaging arm.

10. A lock mechanism according to claim 9, further comprising a

transmission member having a first abutment shoulder arranged for engagement with the engaging arm, and a second abutment shoulder arranged to move the latch bolt to an

unlatched position when the first abutment shoulder is actuated by the

engaging arm corresponding to the rotation of the follower.

11. A lock mechanism according to claim 10, further comprising a further latch bolt and corresponding means to bias the latch bolt to a latched position.

12. A lock mechanism according to claim 11 , wherein the transmission member includes a third abutment shoulder, the first abutment shoulder of the transmission member being actuated by the engaging arm corresponding to the rotation of the follower such that the second and third abutment shoulders move the latch bolts to unlatched positions.

13. In combination, a lock mechanism and a cylinder lock, the lock mechanism being arranged to receive the cylinder lock having a rotatable actuating member, the lock mechanism comprising a bolt, and a rotatable part annular follower having an abutment surface, the abutment surface being arranged to be struck by the actuating member to rotate the follower, the bolt being coupled to the follower and movable rectilinearly in response to the corresponding rotation of the follower.

14. A combination according to claim 13, wherein the follower includes a further abutment surface, the abutment surfaces being arranged to be struck by the actuating member to rotate the follower in respective opposite directions.