AU2010202397A1 - Single handle opening of multiple independently operable locks - Google Patents

Description

1 9 JUN 2010 lIP Ausraia Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Name of applicant/Nominated Person: Trevor David Leisk Address for Service: Davies Collison Cave, Patent Attorneys 1 Nicholson Street, MELBOURNE, Victoria, 3000. Invention title: "Single handle opening of multiple independently operable locks" Details of Associated Provisional Application: Provisional Patent Application No. 2009902824. The following statement is a full description of this invention, including the best method of performing it known to me: 2 Technical field. This invention concerns multiple (typically, two) locks on a single door. More particularly, it concerns a bolt withdrawal arrangement for multiple, independently operated, locks in which a single lever handle (or door knob) is rotated to withdraw, substantially simultaneously, the bolts of each of the multiple locks of the door. Preliminary note. In this specification, including the claims, "directional" terms (such as "top", "bottom", "side", "upper", "lower", "above", "upwardly", "below", "inwardly", "horizontal", "vertical" and the like) will be used in the sense that these terms would have with reference to a mechanism as shown in Figures 1 to 6 of the accompanying drawings. Background to the invention. The use of two locks on a door is common practice. Many householders use a "double deadlock" arrangement on the door of a house or an apartment to improve the security of the dwelling. Some insurance companies either insist on double deadlock arrangements before they will insure the contents of a house, or offer reduced insurance premiums when a double deadlock is fitted. In many commercial and government establishments, double door locks on the access door of a room (or a suite of rooms, an area, a warehouse, a hangar, or the like; henceforth in this specification such locations are referred to collectively by the word "room") are mandatory if entry to a room is to be restricted (for example, because the room contains classified, secret or top secret documents, equipment or activities). Often, differently authorised personnel have the means to unlock, to enter a room, only one of the locks of the door to the room, to further limit who is 3 authorised to have access to the room. If, after a person enters the room through a door having two locks (or more than two locks), each lock is subsequently locked, then each lock must be unlocked when that person wishes to leave the room. That rarely presents a problem. 5 However, in the event of a fire or another hazardous event in the room (for example, a toxic gas leak), the extra time required to unlock and/or withdraw each lock bolt from its locking location can adversely affect those in the room who need to leave it suddenly. That extra time can be significant if the hazard has caused the lights in the room to be extinguished, or if there is a crush of 0 people attempting to leave the room at the same time. Clearly, in such a situation, it would be advantageous if the bolts of the locks on the door could be withdrawn from their locking position at essentially the same time by the rotation of a single handle or door knob. (Henceforth in this specification, the term "handle" will include a door knob or fixed handle as it is 5 sometimes called.) In fact, a recent decision of the Fire Brigade Services in Australia has been that, at a prescribed date in the future, all commercial buildings (including government buildings) will not be certified as complying with the fire regulations unless each door of a room that is equipped with two or more locks can be opened, from inside the room, by a single handle action (rotation of 20 the handle). However, the present inventor is unaware of any commercially available mechanism that enables a single handle rotation action to withdraw, essentially simultaneously, the bolts of multiple, independently lockable, locks from their "locked" location.

4 Disclosure of the invention. Normally, in the case of a latch lock, the bolt withdrawal means of the lock is the lock spindle. In the case of a rim lock or a mechanical - square bolt - deadlock, the bolt withdrawal means is usually the bit of a key. The key bit engages with a notch in the tail of the bolt. It is an objective of the present invention to provide a mechanism whereby two (or more than two) locks on a door may have their bolts withdrawn from their locking locations, essentially simultaneously, by the rotation of a single handle. This objective is achieved, when the door has two locks, (a) by providing each lock on the door with a respective rotatable disc (plate) or rotatable tongue (or arm) that, when rotated, acts to withdraw the bolt of the lock, and (b) connecting the rotatable disc, or tongue, associated with each lock in such a manner that they are rotated essentially synchronously when a single door handle is rotated, and the bolts of the two locks are withdrawn essentially simultaneously. For convenience, I have called the rotatable disc (or plate), or tongue (or arm) of the present invention, which is associated with each lock, a "rotatable member", and this term will henceforth be used in this specification, including the claims. If the lock is a latch lock, the rotatable member associated with this lock may be a single plate or disc that is mounted rigidly on the spindle of the lock. However, the associated rotatable member need not be a single component item, but may be constructed using several components, and it may not be connected directly to the spindle of a latch lock. For example, the rotatable member may be mounted on a bush through which the lock spindle passes, with a pin or other protrusion from the rotatable member engaging with an aperture in, or a recess in the edge region 5 of, a latch plate (or the like) that is mounted on, and rotates with, the spindle of the lock. Such an aperture or recess may be arcuate, to permit some free movement of the rotatable member before its pin or protrusion contacts, and moves (rotates) the latch plate. Another alternative is for the latch plate to be mounted on a bush 5 which surrounds the spindle of the lock, and either (a) a pin (or other protrusion) extending from the rotatable member is located within an aperture in, or within an edge recessed region of, the latch plate (optionally, an elongate, arcuate aperture - an arcuate slot - or an elongate, arcuate recess in the edge of the latch plate), or (b) a pin (or other protrusion) extending from the latch plate is located within an aperture, or within a recess in a curved edge, of the rotatable member (again, optionally, an elongate, arcuate aperture - an arcuate slot - or an elongate, arcuate recess in the edge of the rotatable member). A single handle is connected to the bolt withdrawal means of one of the locks 5 (the first lock; the other lock being the second lock). Rotation of this handle causes rotation of the rotatable member associated with the first lock, and moves the bolt withdrawal means of the first lock (that is, it rotates the spindle of the lock if the first lock is a latch lock, and it moves a tongue which engages with a notch in the tail of the bolt if the first lock is a rim lock or a mechanical deadlock). 0 A mechanical linkage (typically, a connecting rod) between the rotatable member of the first lock and the rotatable member of the second lock ensures that when the handle (and, with it, the rotatable member of the first lock) is rotated, the rotatable member of the second lock is also rotated. Provided the connection point of the linkage (a connecting rod) to the two rotatable members is such that 5 (a) when the rotatable member associated with the first lock is rotated by an amount sufficient to withdraw the bolt of the first lock from its locking position, then 6 (b) the movement of the rotatable member associated with the second lock is sufficient to withdraw the bolt of the second lock from its locking position, the bolts of the two locks will be withdrawn from their locking positions essentially simultaneously. Thus, according to the present invention, there is provided a bolt withdrawal arrangement or mechanism for a door having a first lock with a first bolt withdrawal means and a second lock which is lockable and unlockable independently of said first lock; said second lock having a second bolt withdrawal means; said first lock being spaced apart from said second lock; said bolt withdrawal arrangement comprising: a) a first rotatable member (as hereinbefore defined) operatively connected to said first bolt withdrawal means; b) a second rotatable member (as hereinbefore defined) operatively connected to said second bolt withdrawal means; c) a single rotatable handle, operatively connected to said first rotatable member; and d) a mechanical linkage between said first rotatable member and said second rotatable member; whereby, when rotation of said single handle causes rotation of said first rotatable member and with it movement of said first bolt withdrawal means, (1) said linkage causes rotation of said second rotatable member, and (2) rotation of said second rotatable member causes movement of said second bolt withdrawal means; said movement of said first and second bolt withdrawal means being substantially simultaneous. The linkage between the rotatable members associated with the first and second 7 locks is preferably by a connecting rod or several rods, but any suitable mechanical linkage may be used. A modified form of the bolt withdrawal arrangement for a door having two independently operable locks, each with a respective bolt withdrawal means and each with a respective rotatable member, has a third rotatable member which (a) is rotatable by rotation of the rotatable handle, and with a direct, respective linkage from the third rotatable member to the first and second rotatable members. The present invention is not limited to two locks on a door. Three locks (or, in principle, more than three locks) can be controlled so that their bolt withdrawal means are operated, substantially simultaneously, by rotation of a single handle, if each lock is provided with its own rotatable member and all the individual rotatable members are mechanically linked - directly or indirectly - to the rotatable member of the first lock. Embodiments of the present invention will now be described, by way of example only. In the following description reference will be made to the accompanying drawings. Brief description of the drawings. Figure 1 is a schematic view, from the door side, of door furniture which incorporates a basic form of an arrangement, in accordance with the present invention, for the (substantially simultaneous) withdrawal of the bolts of two locks, which are mounted one above the other on the door. Figure 2 provides two examples of the outside view of the door furniture fitted to the other (outer) face of a door having the door furniture depicted in Figure 1 8 affixed to the inside (room) face of the door. Figure 3 shows, partly schematically, door furniture incorporating a preferred embodiment of the present invention. Figure 4 consists of perspective sketches which illustrate the construction and operation of the rotatable member associated with the top lock controlled by the arrangement shown in Figure 3. Figure 5 is a plan view - partly schematic - of an arrangement whereby a single handle may be connected to the spindle of a latch lock. Figure 6 is a perspective sketch of some of the components of the arrangement shown in Figure 5. Detailed description of the illustrated embodiments. The door furniture illustrated in Figure 1 is for use on the room side of a door having two locks mounted one above the other. This door furniture is designed for the situation in which the lower lock is a latch lock and the upper or top lock is a mechanical dead lock. The door furniture comprises a door plate 10 which has a peripheral wall 18 (hatched in Figure 1), the top surface of which fits flush against the surface of the door when it has been mounted on the door using machine screws that pass through respective apertures 11. Optional small walls 18A, the top surfaces of which are coplanar with the top surface of the peripheral wall 18, surround, or partially surround, each aperture 11. The plate 10 may contain any suitable number of apertures 11. A particularly suitable contruction of the door plate 10 has four apertures 11, as shown in Figure 1. The door plate 10 may be constructed from a metal block, the central portion of which has been milled to 9 remove material to form the peripheral wall 18 (and, if they are present, the small walls 18A). Alternatively, the door plate 10 with its small walls 18 (and 18A) may be cast metal or - if a metal plate is not required - may be moulded. Another alternative is for the lock control mechanism shown in Figure 3 (and described in detail below) to be mounted as flat plate door furniture (for example, mounted on a flat stainless steel plate) which is positioned over a part of the door which has been routed out to accomodate the control mechanism. A first plate 12 (the first rotatable member) has a square aperture 13 passing through it, so that the rotatable member 12 can be mounted on the spindle of a latch lock. A lever handle 14, mounted (in the conventional manner) on the door plate 10, also has a square aperture at its axis of rotation, to receive the spindle of the lower (latch) lock. A second plate (rotatable member) 22 is associated with the second (upper) lock of the door. The rotatable member 22 is connectable, via a tongue, pin, protrusion or the like, to a notch in the tail of the bolt of the upper lock (the upper lock in this embodiment being a mechanical deadlock). A connecting rod 15 is the linkage between the first rotatable member 12 and the second rotatable member 22. The connections of the top and bottom ends of the connecting rod 15 to the rotatable members are pivotal connections at, respectively, pivot points 25 and 26. Rotation of the handle 14 (by moving the remote end of the handle downwardly) causes rotation of the spindle of the lower lock, and thus (a) rotates the rotatable member 12, and (b) starts the withdrawal of the bolt of the lower lock from its locking location. This rotation of the rotatable member 12 moves the connecting rod 15 downwardly, and this causes consequential rotation of the rotatable 10 member 22 about its axis of rotation. Rotation of the rotatable member 22 causes movement of the tail of the bolt of the top lock, and this starts the withdrawal of the bolt of the upper lock from its locking location. Thus the bolts of the upper and lower locks are withdrawn from their locking locations substantially 5 simultaneously by the rotation of the single handle 14, unless there is a degree of slackness in the coupling between (a) the connecting rod 15 and the rotatable members 12 and 22, and (b) the rotatable members 12 and 22 and the bolt. withdrawal means of the upper and lower locks, respectively. 3 In general, it is possible to arrange for the bolts of both locks to be withdrawn to a position such that the door can be opened with rotation of the handle 14 by less than one quarter of a revolution of the lever handle 14. It should be apparent that it is not necessary for the lever handle 14 to be connected directly or indirectly - to the rotatable member of the lower lock when two locks 5 are mounted on a door, one above the other. The lever handle 14 could control, primarily, the bolt of the upper lock. Typically, when two locks are installed in a door, the distance between the adjacent edges of their face plates (that is, the distance between the bottom edge of the face plate of the upper lock and the upper edge of the face plate of the lower lock) is 50 mm. However, not every installer of double locks can position the locks precisely. Accordingly, the connecting rod 15 shown in Figure 1 should be adjustable in length, to accommodate small variations (of the order of 5 mm) in the spacing of the locks on a door. Figure 2 shows door plates 20, which have the same shape and size as the door 11 plate 10 and which may replace the two face plates of the double locks on the outside surface of the door to which the two locks are fitted. In each example of Figure 2, the plate 20 contains the key apertures or cylinder holes 27 and 28 for the locks on the door. In the Figure 2(a) illustration, an external handle 24 is used 5 to open the door from the outside when it has been unlocked. If an "electronic key" is used to unlock the upper or lower lock of the door, (a) the key hole aperture of the (or each) electronically controlled lock will be absent from the door plate 20, and (b) a handle to open the door when the upper and lower locks have each been D released (opened) may be a fixed handle, mounted on the door separately from the door plate 20. A preferred form of the present invention is illustrated by Figures 3 and 4. In Figure 3, some of the features are the same - or are essentially the same - as features of the arrangement depicted by Figure 1, and these features have been designated 5 by the same reference numerals. The arrangement illustrated in Figure 3 has a face plate 10 with a peripheral wall 18, and four apertures 11. Three of the apertures 11 are surrounded by a small wall 18A; the fourth aperture 11 (the lowest in Figure 3) is included in a thicker region 18B of the peripheral wall 18. This arrangement is also designed for use with a 20 door that has two locks, mounted one above the other, with the lower lock being a latch lock and the upper lock being a mechanical deadlock. The rotatable member associated with the lower lock is a plate 30 (which I have called a "fulcrum plate"). The fulcrum plate 30 has a square aperture 13 which enables it to be mounted on the spindle of a latch lock. The fulcrum plate 30 is 25 rotated by the downward movement of the free end of the lever door handle 12 14. Any attempt to rotate the fulcrum plate in the opposite direction is prevented when a nib 31 of the fulcrum plate contacts a stop member 33, which is formed in, or mounted on, the face plate 10. A tongue 30A of the fulcrum plate is bent so that its plane is substantially at right angles to the plane of the fulcrum plate 30. In the embodiment illustrated in Figure 3, the tongue 30A is bent down (that is, into the direction into the paper on which Figure 3 is drawn). In this position, the tongue 30A will engage with the handle return spring of the handle mechanism of the lock associated with the fulcrum plate 30. A circular disc 34 is mounted on an axle 35 which is formed on, or attached to, the face plate 10. Rotation of the disc 34 about the axle 35 is controlled by a rigid connecting strip 37 that is connected to both the circular disc 34 and a lobe 30B of the fulcrum plate 30 at respective pivot points 32. The disc 34 has an arcuate slot 36 in one side region of the disc, and an optional, second arcuate slot 36A in the other side region of the disc. The centre of curvature of the centre-line of each arcuate slot 36, 36A, is the centre of the axle 35. The turned-up lower end 15A of a connecting rod 15 is a sliding fit within the arcuate slot 36. The end 15A is positioned at, or near, the upper end of the arcuate slot 36 so that, when the disc 34 is rotated by the (generally upward) movement of the connecting strip 37, the connecting rod 15 is pulled down. The connecting rod 15 passes behind an optional retaining plate 38, mounted on the face plate 10 (as shown in the sectional detail included in Figure 3). An elongate block 50 having (a) an elongate, threaded, cylindrical cavity extending upwardly from its lowermost surface, and (b) a transverse aperture 51 extending horizontally through its upper region, 13 is mounted on the other (the upper) end 15B of the connecting rod 15. Adjustment of the distance between the aperture 51 and the top end of the arcuate slot 36 is effected by adjusting the extent to which the threaded upper end 15B of the connecting rod 15 is screwed into the cylindrical cavity of the block 50. An optional lock nut 52 on the end 15B is also shown in Figures 3 and 4. The rotatable member associated with the upper lock with which the embodiment of Figures 3 and 4 is to be used is the arm 54 shown particularly in Figure 4. This flat arm 54 has two faces 54A and 54B. A pin 53 extends from its face 54A, near one end of the arm 54. The pin 53 is dimensioned to be a sliding fit within the transverse aperture 51 of the block 50. A cylindrical bar 55 extends from the other face, 54B, near the other end of the arm. A tongue 56, formed integrally with (or attached rigidly to) the cylindrical bar 55, extends from the end of the bar 55 that is remote from the face 54B. Thus the cylindrical bar 55 is a tongue supporting member. The length of the bar 55 is such that the tongue 56 engages with the top lock to act as a bolt withdrawal means. (If the top lock is a latch lock, and not a rim lock or a mechanical deadlock, the tongue 56 will normally have square cross-section; however, the shape of the tongue 56 will be subject to the type of cam required for the functionality of the lock.) The cylindrical bar 55 is a sliding fit within a cylindrical aperture 58 in a rod 57 that has a length that is comparable to the length of the arm 54. A small block 59 is formed integrally with, or is attached to, one face of the rod 57. The small block 59 has a vertical hole 60 in it. The retaining pin, of the upper lock of the door with which the embodiment of Figures 3 and 4 is to be used, is inserted into the hole 60, thus securing the rod 57 to the upper lock. The thickness of the rod 57 is such that, when the cylindrical bar 55 is fully inserted 14 into the aperture 58, the tongue 56 extends beyond the face of the bar 57 that is remote from the arm 54. In this position, the tongue 56 engages with a notch in the tail of the bolt of the upper lock, so that rotation of the tongue 56 will withdraw the bolt of the upper lock from its locked position. Since the bar 57 is fixed in position by the retaining pin of its associated lock, rotation of the bar 55 is caused by rotation of the arm 54 aboout the axis of the cylindrical bar 55. That occurs when the pin 53 is pulled downwardly by downward movement of the block 50, as a result of movement of the connecting rod 15 when the disc 34 is rotated as a consequence of the rotation of the fulcrum plate 30. All components of the mechanism illustrated in Figures 3 and 4 are preferably constructed using steel. The additional (and optional) arcuate slot 36A is included in the disc 34 for convenience, so that the arrangement shown in Figure 3 can be used with a "left hand door", simply by (a) relocating the end 15A of the connecting rod 15 into the slot 36A, and (b) using a "mirror image" form of the fulcrum plate 30, with the tongue 30A on the right of the aperture 13 and extending in the direction out of the paper on which Figure 3 is drawn. A variation of the Figure 3 embodiment is for the disc 34 to be rotated by the lever handle 14, and for separate, respective (mechanical linkages) to extend from the disc 34 to (a) the fulcrum plate 30 and (b) the block 50. Those mechanical linkages will be so arranged that when disc 34 is rotated by the lever handle 14, (1) the fulcrum plate 30 will be rotated, with consequential rotation of the spindle of the latch lock on which it is mounted; and (2) the block 30 will be pulled down, thereby rotating the tongue 56 and withdrawing the bolt of the top (upper) lock.

15 Although the illustrated embodiments described above illustrate the use of the present invention with a door fitted with a latch lock and a mechanical deadlock, it will be apparent to locksmiths that the present invention can also be used when (1) each lock on a door is a latch lock, or each lock on a door is a mechanical deadlock; (2) the door locks are not mounted one above the other, vertically; (3) the locks have their bolts extending from the top of a wide door, and thus are spaced apart horizontally; and (4) three or more locks are on the same door (if appropriately located connecting rods provide linkages between their respective rotatable members). Other features may be included in the bolt withdrawal arrangement of the present invention. One such additional feature is the provision of a shroud or protective box, open at the top (typically of steel or an acrylic compound) around the lever handle 14, so that the handle cannot be accidentally rotated to a position in which the bolts of each lock on the door are withdrawn from their locking positions. Another additional feature is to have the rotatable member associated with the upper lock of an arrangement requiring the door furniture of Figures 1 or 3 linked to the rotatable member of the lower lock in such a manner that, when the handle 14 is rotated in the opposite direction to that required for bolt withdrawal (that is, the free end of the handle 14 is moved upwardly), the bolt of the upper lock is moved into its locking position. With this arrangement in a security environment, an authorised person who has entered a room using an electronic key (a) can re-lock the upper lock to prevent subsequent entry into the room by an unauthorised person; but 16 (b) will retain the ability to escape quickly from the room in an emergency, by withdrawing both lock bolts with downwards movement of the free end of the lever handle 14. A further additional feature, to prevent accidental rotation of the handle 14 when the lower lock is a latch lock, is illustrated in Figures 5 and 6. The mechanism shown in these Figures has a short spindle 40, having a rectangular (in this embodiment, a square) vertical cross-section (it is not essential for this cross section to be rectangular). The "axis" of the spindle 40 is aligned with the axis of rotation of the handle 14, and rotation of the handle 14 rotates the spindle 40. A helical spring 41 is connected to both the spindle 40 and to the support plate 43 for the handle return spring 14A. The helical spring 41 biases the spindle 40 towards the support plate 43. The spindle 40 is aligned, horizontally, with the spindle 44 of the latch lock, which (as is usual) has a square vertical cross-section. A vertical bar 48, of rectangular horizontal cross-section, is securely mounted at the end of (optionally formed integrally with) the spindle 40 which is remote from the helical spring 41. A pin 42 of circular cross-section extends horizontally from the bar 48. The end of the pin 42 which is remote from the spindle 40 is positioned in a cylindrical cavity 49 that extends horizontally into the spindle 44 from a vertical groove 47, of rectangular horizontal cross-section, that is formed in the end of the latch lock spindle 44 that is closest to the spindle 40. When the components of this feature are positioned as shown in Figures 4 and 5, rotation of the spindle 40 by the handle 14 will cause the pin 42 to rotate in the aperture in the latch lock spindle 44, and the spindle 44 will not rotate. To rotate the spindle 44, a button 45, at the end of a rod 46 that is connected to the short spindle 40, has to be pressed (for example, by the thumb of an operator) to force 17 the spindle 40 to move, against the restraining force of the helical spring 41, towards the spindle 44. Such movement of the spindle 40 (a) causes the horizontal pin 42 to penetrate further into the cavity 49 in the spindle 44, and (b) brings the bar 48 into the vertical groove 47 in the spindle 44. When the bar 48 is positioned within the groove 47, rotation of the handle 14 will produce corresponding rotation of the spindle 44 with the spindle 40. For public buildings, the arrangement illustrated in Figures 5 and 6 is unlikely to be approved because, to operate the bolt withdrawal mechanism, two actions are required, namely, the pressing of the button 45 and the rotation of the lever handle. A single action, to withdraw the bolts of the two locks, is preferred. In the introduction part of this specification, it has been suggested that a door knob, instead of a lever handle, may be used. In principle, that is correct. However, in public buildings, door knobs, because they may require a degree of dexterity (that may not be possessed by some people who are incapacitated - for example, by arthritis) to turn them, are unlikely to be specified. However, domestic applications of the present invention may be operated with a door knob. Locksmiths should appreciate that the illustrated embodiments are provided by way of example only, and that variations and modifications of the illustrated D embodiments may be made without departing from the present inventive concept.

Claims (15)

1. A bolt withdrawal mechanism for a door having a first lock with a first bolt withdrawal means and a second lock which is lockable and unlockable independently of said first lock; said second lock having a second bolt withdrawal means; said first lock being spaced apart from said second lock; said bolt withdrawal mechanism comprising: a) a first rotatable member (as hereinbefore defined) operatively connected to said first bolt withdrawal means; b) a second rotatable member (as hereinbefore defined) operatively connected to said second bolt withdrawal means; c) a single rotatable handle, operatively connected to said first rotatable member; and d) a mechanical linkage between said first rotatable member and said second rotatable member; whereby, when rotation of said single handle causes rotation of said first rotatable member and with it movement of said first bolt withdrawal means, (1) said linkage causes rotation of said second rotatable member, and (2) rotation of said second rotatable member causes movement of said second bolt withdrawal means; said movement of said first and second bolt withdrawal means being substantially simultaneous.

2. A bolt withdrawal mechanism for a door having a first lock with a first bolt withdrawal means and a second lock which is lockable and unlockable independently of said first lock; said second lock having a second bolt withdrawal means; said first lock being spaced apart from said second 19 lock; said bolt withdrawal mechanism comprising: a) a first rotatable member (as hereinbefore defined) operatively connected to said first bolt withdrawal means; b) a second rotatable member (as hereinbefore defined) operatively connected to said second bolt withdrawal means; c) a third rotatable member positioned between said first rotatable member and- said second rotatable member; c) a single rotatable handle, operatively connected to said third rotatable member; and d) a first mechanical linkage between said first rotatable member and said third rotatable member, and a second mechanical linkage between said second rotatable member and said third rotatable member; whereby, when rotation of said single handle causes rotation of said third rotatable member; (1) said first mechanical linkage causes rotation of said first rotatable member and with it movement of said first bolt withdrawal means; and (3) said second mechanical linkage causes rotation of said second rotatable member and with it movement of said second bolt withdrawal means; said movement of said first and second bolt withdrawal means being substantially simultaneous.

3. A bolt withdrawal mechanism as defined in claim 1 or claim 2, in which said first lock is a latch lock, said first bolt withdrawal means is the spindle of said latch lock, and said first rotatable member is a disc having a square aperture therein, said square aperture being a close fit on said spindle of said first lock. 20

4. A bolt withdrawal mechanism as defined in claim 1 or claim 2, in which said first lock is a latch lock, and said first rotatable member is mounted on a bush through which the spindle of said first lock passes, further characterised in that a pin or other protrusion from said first rotatable member is engaged with an aperture in, or a recess in the edge region of, a latch plate that is mounted on, and rotates with, the spindle of said first lock.

5. A bolt withdrawal mechanism as defined in claim 1 or claim 2, in which (a) said first lock is a latch lock, and (b) a latch plate is mounted on a bush which surrounds the spindle of said first lock; and either (1) a pin or other protrusion which extends from said rotatable member is located within an aperture in, or within an edge recessed region of, said latch plate, or (2) a pin or other protrusion which extends from said latch plate is located within an aperture, or within a recess in a curved edge, of said first rotatable member.

6. A bolt withdrawal mechanism as defined -in claim 4 or claim 5, in which said aperture or recess is an arcuate aperture or recess.

7. A bolt withdrawal mechanism as defined in any one of claims 3 to 5, in which said second lock is also a latch lock.

8. A bolt withdrawal mechanism as defined in any preceding claim, in which said second lock is a rim lock or a mechanical deadlock, and said second bolt withdrawal means of said second lock comprises a rotatable tongue positioned in a notch in the tail of the bolt of said at least one lock. 21

9. A bolt withdrawal mechanism as defined in claim 1 or claim 2, in which each of said locks is a rim lock or a mechanical deadlock, and said first and second bolt withdrawal means each comprise a rotatable tongue positioned in a notch in the tail of the bolt of said at least one lock.

10. A bolt withdrawal mechanism as defined in claim 8 or claim 9, in which said rotatable member associated with said or each rim lock or mechanical deadlock is a respective rotatable disc that is operatively connected to the associated tongue of the bolt withdrawal means of said or each rim lock or mechanical deadlock.

11. A bolt withdrawal mechanism as defined in claim 8, in which said rotatable disc is directly connected to said tongue.

12. A bolt withdrawal mechanism as defined in claim 8 or claim 9, in which (1) said rotatable member associated with said or each rim lock or mechanical deadlock comprises an arm; (2) a respective cylindrical tongue supporting member extends from one side of said or each arm, near one end thereof, with the axis of said or each cylindrical tongue supporting member being substantially horizontal; (3) said or each tongue is located, respectively, at the end of said or each cylindrical tongue supporting member that is remote from its associated arm; and (4) said or each cylindrical tongue supporting member is a sliding fit within a respective cylindrical aperture that passes horizontally through an associated bar that is securely mounted on said or each lock; said or each bar being so positioned, and having a width such 22 that, when said mechanism is in use, said or each cylindrical tongue supporting member extends through its associated bar and said or each tongue is located within a respective notch in the tail of said or each bolt; whereby the axis of said or each cylindrical tongue supporting member is the axis of rotation of its associated arm.

13. A bolt withdrawal mechanism as defined in claim 12, in which a respective pin extends substantially horizontally from the other side of said or each arm, near the other end of said or each arm, and said or each pin is connected to a respective mechanical linkage.

14. A bolt withdrawal mechanism as defined in claim 1, in which said first lock is a latch lock, the bolt of which is controlled by the rotation of a first spindle that is mounted on a shaft attached to said handle, said shaft being rotated when said handle is rotated; and said first rotatable member is a second spindle which is aligned with and adjacent to, but spaced from, said first spindle; characterised in that a) said second spindle has a vertical groove in a face thereof that is adjacent to said first spindle and a cylindrical cavity which extends horizontally into said second spindle from siad vertical groove; b) said first spindle has a face adjacent to said said second spindle on which is mounted a vertical bar having dimensions that enable it to be positioned within said vertical groove of said second spindle; a pin extending horizontally from said vertical bar into said cavity in said second spindle; c) said first spindle is connected to said shaft by a helical spring that (1) is attached at one end to a face of said first spindle that is remote 23 from said second spindle; (2) is attached at its other end to a support plate mounted on said shaft; and (3) biases said first spindle towards said support plate; d) a rod extends, through a horizontal channel in said shaft, from a button outside said handle to said first spindle; whereby pressing said button towards said handle moves said rod within said channel to move said first spindle, against the bias of said helical spring, so that said vertical bar becomes positioned within said vertical groove and said horizontal pin extends further into said cavity, and rotation of said handle causes rotation of said second spindle.

15. A bolt withdrawal mechanism for a door having multiple locks, as defined in claim 1 or claim 2, substantially as hereinbefore described with reference to the accompanying drawings. Dated this ninth day of June, 2010. TREVOR DAVID LEISK by his Patent Attorneys DAVIES COLLISON CAVE