AU2009101386A4 - A Sliding Door Lock - Google Patents

Abstract

Abstract A lock having a latch tongue movable between a latching position and an unlatching position, a locking member movable between an unlocking position and a deadlocking position, wherein when the locking member is in the deadlocking position the latch tongue is prevented from moving from the latching position to the unlatching position, a cylinder having a cam which can move between a first position and a second position, wherein moving the cam into the second position moves the locking member into the deadlocking position, and a detent member that has a biasing portion integrally formed with the detent member from a plastic or polymer material, wherein the detent member must be deflected against the bias of the biasing portion for the cam to move, at least, from the second position to the first position.

Description

Editorial Note 2009101386 There are 12 pages of Description 1 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Invention Title: A Sliding Door Lock Applicants: Ass Abloy Australia Pty Limited The invention is described in the following statement.

1 Field of the Invention. The present invention relates to a lock. The lock may find particular use on sliding wings such as sliding doors or windows, although no particular limitation is to be implied from this and other possible uses or applications for the lock are also possible. 5 Background Art. Conventional locks for sliding doors, windows or the like allow simple latching and unlatching of the door or window. Typically, these locks have one or more levers on the lock's external furniture for facilitating the simple latching and unlatching of the door or window. 10 However, many sliding door or window locks are also provided with a cylinder (typically but not exclusively a key operated cylinder) so that the lock may be deadlocked in order to provide additional security. In many such locks, the cylinder has a cam which engages with one or more biased or spring-loaded components inside the lock when the cylinder is operated. One particular prior art lock is shown in 15 Figures 1-2. The lock 10 in Figures 1-2 is shown in a deadlocked condition in which a locking member 11 is engaged with the latch tongue 12 to prevent pivotal movement of the latch tongue 12. Although not shown in Figure 1, a cylinder (most likely a key operated cylinder) is positioned in the. "keyhole" shaped opening 13. The key cylinder 20 has a cam (not shown) associated with it which can be rotated by turning a key (not shown) in the key cylinder. Key cylinders of this type will be well known to those skilled in this area. The key cylinder cam can rotate upwards (in this illustration) to engage with the underside of locking member 11 to thereby push the locking member 11 up into the deadlocking position shown. However, the cam can also rotate 25 downwards (in this illustration) to allow the locking member 11 to slide downwards (in this illustration) out of engagement with the latch tongue 12, thereby un deadlocking the lock. The lock also has a detent member 14. When the key cylinder cam is rotated up underneath the locking member 11 to push the locking member into the deadlocking 30 position, the detent member projects out to help prevent the cam (and also the locking 2 member 11) from sliding back down in the lock under gravity. Specifically, when the lock is in the deadlocked configuration, the cylinder cam rests against the detent member 14 but the weight of the cam (and that of the locking member 11) is not enough to displace the detent member and allow the cam to move down past the 5 detent member. The detent member 14 also helps to provide resistance to movement of the key cylinder cam which enables the user to "feel" when they turn the key to convert the lock from the un-deadlocked to the deadlocked condition and vice versa. The section of the lock 10 marked "B" in Figure 1 is illustrated in Figure 2. In this Figure, the 10 detent member 14 can be more clearly seen. The detent member comprises a body 15 and a helical/coil spring 16. As the cam (not shown) rotates (either up or down), it initially contacts the curved surface 17 of the body 15. With further rotation, the cam pushes on, and slides past, the curved surface 17, thus forcing the body 15 to slide back (i.e. to the left in the drawings) against the bias of spring 16. The noticeable 1 effort that the user must apply to force the cylinder cam past the detent member 14 as they turn the key is what helps to provide the "feel" described above. The amount of effort is enough to be noticed by the user, but not enough to make the key difficult to turn. Whilst the prior art lock shown in Figures 1-2 has been quite successful, the particular 20 configuration of the detent member and its associated components are considered to suffer from certain deficiencies. For instance, grease or other lubricant must be applied to the point where the helical spring 16 engages with the body 15 of the detent member, and also where the spring 16 engages with the lock casing. After the grease has been applied, the body 15 and the spring 16 must be assembled into the lock 25 casing, and this can be quite "fiddly". The cost of the grease, the increased assembly time/complexity, and also the cost of the helical spring itself all contribute to increased manufacturing costs. It will be clearly understood that any reference herein to background products or material, prior publications or technical problems does not constitute an 30 acknowledgement or admission that any background material, prior publication(s), technical problem(s) or combination(s) thereof formed part of the common general 3 knowledge in the field or is otherwise admissible prior art, whether in Australia or any other country. Throughout this specification, the term "comprising" and its grammatical equivalents shall be taken to have an inclusive meaning unless the context of use indicates 5 otherwise. Object of the Invention. It is an object of the present invention to provide a lock which may help to ameliorate some of the abovementioned deficiencies, or at least provide a useful or commercial alternative to other locks in the marketplace. 10 In one aspect, the invention resides broadly in a lock having a latch tongue movable between a latching position and an unlatching position, a locking member movable between an unlocking position and a deadlocking position, wherein when the locking member is in the deadlocking position the latch tongue is prevented from moving from the latching position to the unlatching position, 15 a cylinder having a cam which can move between a first position and a second position, wherein moving the cam into the second position moves the locking member into the deadlocking position, and a detent member that has a biasing portion integrally formed with the detent member from a plastic or polymer material, and 20 wherein the detent member must be deflected against the bias of the biasing portion for the cam to move, at least, from the second position to the first position. Forming the detent member integrally with the biasing portion provides a number of advantages. For instance, the need for a separate spring is eliminated and the need for pre-assembly lubrication is also significantly reduced. It is even possible that, with 25 some polymers, no lubrication may be required at all. Thus, the component count and the manufacturing costs for the lock are reduced. Furthermore, assembly is simplified by eliminating the need for a separate biasing element (spring). Another possible advantage of the present invention relates to the ability to make 4 locks slimmer/thinner. In the case of mortice locks like the prior art lock shown in Figures 1-2, making the lock thinner can enable the lock to be installed in doors and windows having narrower frame/edge profiles. One reason why the present invention may help to enable the thickness of the lock to be reduced compared with, for 5 example, the prior art lock which had a helical spring is because, in order for a helical spring to provide a sufficient spring force, the spring generally needs to be a particular size/diameter. Reducing the size/diameter of the helical spring cannot generally be done without also reducing the stiffness of the spring, and consequently simply substituting a smaller/thinner spring may not be possible as the smaller spring may not 10 provide sufficient spring force. By eliminating the need for a separate helical spring, the present invention may help to address this difficulty. The lock will typically have a lock casing, which may be of any suitable form. However, in a preferred embodiment of the invention the lock casing may comprise a front wall, a rear wall, a bottom wall, a top wall and a pair of opposed side walls. The 15 front wall may include one or more openings adapted to allow a strike hook to enter the lock body and engage with the latch tongue, at least in embodiments where the latch tongue is a rotating "parrot beak" type latch tongue. Other latch tongue configurations are also possible. At least the sidewall of the casing which is adjacent the outside of the door/window 20 (and possibly also the inside sidewall of the casing) may have an opening therein adapted to allow the key cylinder to project therethrough such that the cylinder may be accessed from outside the lock on at least the outside (and possibly also the inside) of the door/window. One or more further openings may be provided in at least one of the top wall, bottom wall, rear wall or one or more of the side walls, the one or more 25 further openings being adapted to allow part of the lock furniture to project therethrough. The lock furniture may be of any suitable form and may include one or more handles, levers, snibs or the like, or any combination thereof. In some embodiments of the invention, the latch tongue may be rotatably mounted in the lock body. Preferably, the latch tongue is biased by bias means into the latched 30 position in which it may engage with a strike hook. The latch tongue may be rotated to the unlatched position against the bias of the biasing means. The rotation of the 5 latch tongue to the unlatched position may be achieved by the actuation of one or more operating members within the lock body. The one or more operating members may be actuated by one or more external actuating means. Any suitable external actuating means may be used, although it is envisaged that the external actuating 5 means may comprise one or more items or parts of the lock furniture. Preferably, the lock further includes means to prevent the actuation of the one or more operating members in order to retain the latch tongue in the latched position. This may be in addition to any deadlocking mechanism. Any suitable means may be used for this purpose. 10 The locking member may be of any suitable form. In a preferred embodiment of the invention, the locking member may comprise at least one engagement portion. The at least one engagement portion may be adapted to engage with the latch tongue such that, when the at least one engagement portion is engaged with the latch tongue, it causes the deadlocking of the latch tongue in the latched position. 15 In some embodiments of the invention, the locking member may comprise one or more further engagement portions. The one or more further engagement portions may be adapted to engage with the cam such that, as the cam rotates from the first position to the second position, the cam engages the one or more further engagement portions and moves the locking member from the unlocking position to the deadlocking 20 position. In a preferred embodiment of the present invention, the locking member may be adapted to slide between the deadlocked position and the unlocked position, although those skilled in the area will understand that any suitable technique could be used to move the locking member. 25 As explained above, the lock includes a detent member that has a biasing portion integrally formed therewith. The detent member is formed from a plastic or polymer material, although no strict limitation as to the exact material or process for the manufacture of the detent member is to be implied. Nevertheless, it is envisaged that the detent member will be moulded (probably injection moulded) from a robust, 30 fatigue resistant engineering polymer or plastic.

6 In a preferred embodiment of the invention, the biasing portion of the detent member comprises one or more resilient members adapted to flex, bend, deflect or otherwise (elastically) deform as the cam moves between the first position and the second position. In some embodiments of the invention, as the cam rotates between the first 5 and second positions, the cam comes into contact with the detent member, thereby causing deflection of the biasing portion and moving the detent member into a deflected position. As a result of this deflection, the cam may rotate past the detent member and into its new position. Once the cam has rotated past the detent member, the detent member returns to its original (undeflected) position. When the detent 10 member is in the undeflected position, the cam cannot rotate past the detent member unless sufficient force is provided to overcome the bias provided by the biasing portion. It is envisaged that sufficient force to overcome the bias of the detent member will only be provided by turning a key in the key cylinder, or otherwise operating the cylinder (e.g. if it is some other form of non-key operated cylinder). 15 In a preferred embodiment of the invention, the detent member moves between the deflected position and the undeflected position in a sliding motion, although those skilled in this area will understand that other configurations and other forms of movement are also possible. According to further aspect of the invention, there is provided a lock including 20 a latch tongue movable between a latching position and an unlatching position, a locking member movable between an unlocking position and a deadlocking position, wherein when the locking member is in the deadlocking position the latch tongue is prevented from moving from the latching position to the unlatching position, a cylinder having a cam which can move between a first position and a second 25 position, wherein moving the cam into the second position moves the locking member into the deadlocking position, and a detent member which is formed from a plastic or polymer material and which has an engagement portion and a biasing portion which is integrally formed with the engagement portion, and 30 wherein the engagement portion must be deflected against the bias of the 7 biasing portion for the cam to move, at least, from the second position to the first position. The engagement portion may have a curved outer surface against which the cam acts when the cam is moved, at least, from the second position to the first position thereby 5 causing the detent member to be deflected. Preferably the biasing portion readily causes the engagement portion to be moved back to the undeflected position once the cam has moved past the engagement portion. The bias of the biasing member may be such that the cam can be supported by the engagement portion so that the cam is prevented from being moved from the second 10 position to the first position without the cam being forced past the engagement portion. Brief Description of the Figures. Figures 1 and 2 relate to a prior art lock and are provided to assist in understanding the invention. One particular embodiment of the invention is shown in Figures 3-6. It 15 will be clearly appreciated that the various Figures and associated descriptions are provided to assist in understanding the invention only, and the invention is not necessarily limited to or by the particular features described and shown. Figure 1 illustrates a prior art lock; 20 Figure 2 illustrates a detailed view of the prior art lock in Figure 1; Figure 3 illustrates a lock according to an embodiment of the present invention when in an unlocked state; Figure 4 illustrates a detailed view of the lock in Figure 3, again, in an unlocked state; 25 Figure 5 illustrates the lock in Figure 3, but in a deadlocked state; Figure 6 illustrates a detailed view of the lock the lock in Figure 3 wherein, like Figure 5, the lock is shown in a deadlocked state.

8 Detailed Description of Figures 3-6. In Figure 3, a lock 20 according to an embodiment of the present invention is illustrated. The lock 20 comprises a casing having a front wall 21, a rear wall 22, a top wall 23, and a bottom wall 24. The lock casing also has a pair of opposed side 5 walls. One of the sidewalls is visible behind the other components of the lock in Figures 3-6. The other sidewall is formed by a cover plate which has been omitted in the Figures to show the lock's internal components. The lock 20 comprises a latch tongue 25 adapted for pivotal movement about a pivot point 26. The latch tongue 25 is illustrated in the latched position. The latch tongue 10 25 may be rotated (clockwise in this illustration) to the unlatched position by actuation of an operating member 27. This is done by manually operating a lever handle (not shown) which is on the outside of the lock and forms part of the furniture. The lever handle (not shown) connects to the operating member 27 via a square spindle which inserts into a square aperture in operating member 27. Hence, rotating the lever 15 handle causes corresponding rotation of the operating member 27, which in turn pivots the latch tongue 25. Whilst latch tongue 25 can be rotated from a latching position shown into an unlatching position as described above, nevertheless the latch tongue 25 is biased towards the latching position by a spring biased latch tongue return mechanism 28. 20 Consequently, the user must apply sufficient force to the lock's external operating handle to pivot the latch tongue 25 against the spring bias of the return mechanism 28. Then, when the user lets go of the handle, the latch tongue is returned to the latching position by the return mechanism. As described above, rotating the lever handle (not shown) in a first direction results in 25 a corresponding rotation of the operating member 27, which in turn pivots the latch tongue 25. However, if the lever handle (not shown) is rotated in a second (opposite) direction, the operating member 27 rotates until it abuts a contact surface 30 of the return mechanism 28. In this position, movement of the latch tongue return mechanism 28 against the bias of the spring is not possible since abutment of the 30 contact surface against the operating member 27 prevents movement of the return mechanism away from towards the top wall 23. Thus, the latch tongue 25 will be 9 prevented from rotating to the unlatched position, thereby providing the lock 20 with an added security feature. When the operating member 27 is in the position illustrated in Figure 3, it is retained in position by a spring member 32, which engages with a corresponding first groove 5 34 in the surface of the operating member 27. As the operating member 27 rotates into contact with the latch tongue return mechanism 28, the spring member 32 deflects as a projection 36 located on the surface of the operating member 27 slides past the spring member 32. Once the projection 36 has slid past, the spring member 32 will be biased into a second groove 38 in the surface of the operating member 27. Preferably, 10 the spring member 32 is biased into the second groove 38 (and into the first groove 34 when being returned to the position shown in Figure 3) with an audible sound, such as a click or the like, such that the user will immediately know that the operating member 27 is in the desired position. It is envisaged that the operating member 27 will only be able to overcome the bias of 15 the spring member 32 when sufficient force is applied to the lever handle (not shown) by the user to rotate the operating member 27 back to the position illustrated in Figure 3. The lock 20 further comprises a locking member 40, the movement of which is actuated by the rotation of a cam 42. Rotation of the cam 42 is actuated by operation 20 of a cylinder 44. Typically, the cylinder 44 will be keyed from both sides so that a key can be inserted to operate the cylinder from both sides of the door/window. However, it is also possible that the cylinder, or one side thereof, may have a turn knob or some other operating means instead of a conventional key slot. A detent member 46 is also present in the lock 20. The detent member 46 comprises 25 an engagement portion 48 and a biasing portion in the form of an arcuate resilient spring member 50 which is integrally formed with the engagement portion. As the cam 42 rotates between the first position 52 (pictured in Figure 3) and the second position 54 (see Figure 5), the cam 42 contacts a curved outer surface 56 of the detent member 46, thereby causing deflection of the spring member 50 and resulting in a 30 sliding movement of the detent member 46 towards the front wall 21 of the lock 20. Once the cam 42 rotates past the curved outer surface 56 of the detent member 46, the 10 deflection of the spring member 50 ceases and the detent member 46 returns to the undeflected position shown in Figure 3. From Figure 4 it may be seen that the cam 42 is adapted to contact and slide past the curved outer surface 56 of the detent member 46. As it does, the spring member 50 5 deflects, resulting in a sliding movement of the detent member 46 towards the front wall 21 of the lock 20. As the cam 42 rotates it engages with the locking member 40, thereby forcing the locking member 40 to move from an unlocking position 58 which is shown in Figure 3 to a deadlocking position 60 which is shown in Figure 5. . 10 In Figure 5, the lock 20 is shown in a deadlocked condition. In this Figure, the cam 42 has been rotated to the second position. The movement of the cam 42 has produced a corresponding movement of the locking member 40, due to the engagement of the cam 42 with a first engagement portion 62 of the locking member 40. In the deadlocked condition, a second engagement portion 64 of the locking 15 member 40 engages with the latch tongue 25 such that the latch tongue is unable to pivot. Thus, in this position, the latch tongue 25 cannot be moved unless the cam 42 is rotated back to the first position illustrated in Figure 3. In the deadlocked condition illustrated in Figure 5, the cam 42 is prevented from rotating (for instance, under gravity) back to the first position by the presence of the 20 protruding detent member 46. The spring member 50 provides a bias that, in practice, can only be overcome by the application of a force to the cam 42, and particularly by operating the cylinder 44. In Figure 6, a detailed view of the lock 20 shown in Figure 5 is given. In this Figure, the cam 42 has been rotated into the second position, thereby causing the locking 25 member 40 to move upwardly and engage with the latch tongue 25. The detent member 46 is in the undeflected position. To take the lock 20 out of the deadlocked condition, the cylinder 44 would need to be operated (e.g. by turning a key), resulting in the cam 42 contacting the curved outer surface 56 of the detent member 46. The force of this would be sufficient to overcome the bias of the spring member 50, and 30 the cam 42 and locking member 40 would return to the first position illustrated in 1 Figure 3. Those skilled in the art will appreciate that the present invention may be susceptible to variations and modifications other than those specifically described. It will be understood that the present invention encompasses all such variations and 5 modifications that fall within its spirit and scope.

Claims (10)

1. A lock including a latch tongue movable between a latching position and an unlatching position, a locking member movable between an unlocking position and a deadlocking 5 position, wherein when the locking member is in the deadlocking position the latch tongue is prevented from moving from the latching position to the unlatching position, a cylinder having a cam which can move between a first position and a second position, wherein moving the cam into the second position moves the locking member into the deadlocking position, and 10 a detent member which is formed from a plastic or polymer material and which has an engagement portion and a biasing portion which is integrally formed with the engagement portion, and wherein the engagement portion must be deflected against the bias of the biasing portion for the cam to move, at least, from the second position to the first 15 position.

2. A lock according to claim 1 wherein the engagement portion has a curved outer surface against which the cam acts when the cam is moved, at least, from the second position to the first position thereby causing the detent member to be 20 deflected.

3. A lock according to claim 1 or 2 wherein, once the cam has moved past the engagement portion, the biasing portion causes the engagement portion to be moved back to the undeflected position. 25

4. A lock according to claim 1, 2 or 3 wherein the biasing portion includes one or more resilient members adapted to deform thereby allowing the engagement portion to be deflected so that the cam can be moved, at least, from the second position to the first position. 30

5. A lock according to any one of claims 1 to 4 wherein the engagement portion is moved between the deflected and undeflected positions in a sliding motion. 13

6. A lock according to any one of claims 1 to 5 wherein the bias of the biasing member is such that the cam can be supported by the engagement portion so that the cam is prevented from being moved from the second position to the first position without the cam being forced past the engagement portion. 5

7. A lock having a latch tongue movable between a latching position and an unlatching position, a locking member movable between an unlocking position and a deadlocking position, wherein when the locking member is in the deadlocking position the latch 10 tongue is prevented from moving from the latching position to the unlatching position, a cylinder having a cam which can move between a first position and a second position, wherein moving the cam into the second position moves the locking member into the deadlocking position, and a detent member that has a biasing portion integrally formed with the detent 15 member from a plastic or polymer material, and wherein the detent member must be deflected against the bias of the biasing portion for the cam to move, at least, from the second position to the first position.

8. A lock substantially as illustrated with reference to any one of Figures 3 to 6. 20

9. A detent member for use with a lock being formed from a plastic or polymer material and being of unitary construction and comprising an engagement portion and a biasing portion for biasing the engagement portion into engagement with a cam of the lock. 25

10. A detent member as defined in claim 8 and substantially as shown in one or more of the accompanying Figures. 30