GB2337294A - Locking mechanism - Google Patents

Abstract

A locking mechanism comprises a casing (10) in which two followers (13, 30) are mounted for angular movement, the followers being directly connected to a common sliding drive link (58) by respective links (22, 36), with lost motion between each follower and its associated link. A latchbolt (46, 49) is biased to extend from the casing, being retractable by an actuator (41) operated by movement of one of the followers (13), whilst a hookbolt (22) constituting one of the links is moved into or out of the casing by movement of that one of the followers. The drive link is slidable to an operative position, where it can actuate upper and lower secondary locking members, and in the operative position the hookbolt is extended from the casing. The drive link can be locked against release from the operative position by actuation of a key operated cylinder lock, such locking also retaining the hookbolt in its extended position.

Description

2337294 LOCKING MECHANISM This invention relates to a locking mechanism

for a pivotable wing, such as a door, the mechanism in particular forming a central unit of a multipoint locking system.

An object of the invention is toProvide such a mechanism in an efficient yet simple manner.

According to a first aspect of the invention, there is provided a locking mechanism for a movable wingcomprising a follower for the connection thereto, in use,, of an operating imember at one side of said wing, a link connected directly between the follower and a link slidable between first and second positions, angular movement of the follower in one direction being arranged to effect slidingof said slidable link through movement of its associated connected link, aod-means for retaining said slidable link in one of its first and second posith-ms.

Preferably the mechanism comprises a second follower for the connection thereto, in use, of an operatin mber at the other side of said wing, and a second link connected diretween the second follower and said slidable link, angular movernert-of the second follower in one direction being arranged to effect sliding-d-said slidable link through movement of said second link.

In an alternative manner of use66f the mechanism, the operating members are both connected to said foilr. This allows opening of the wing, in AW normal use, by operation of either operating member, i.e. from outside and inside of the door.

More preferably the mechanism includes a casing from which a latchbolt is biased normally to extend, said means for retaining said common link in one of its first and second positions being locking means, which, when actuated. also retain said latchbolt against inward movement towards the casing from its extended position.

Desirably said link is in the form of a bolt extendable from and retractable into the casing upon angular movement of said follower in respective opposite directions. Conveniently the bolt constituted by said link is a hook bolt.

Advantageously said follower has a projection which, upon angular movement of said follower to retract the hook bolt, acts upon an actuator which retracts said latchbolt into said casing. More advantageously there is lost motion between each follower and its associated link.

More preferably, the connection between each of said link and the second link and said slidable common link is by way of a peg and slot.

According to a further aspect of the invention, an arrangement of two relatively movable members comprises a first member angularly movable about an axis, a second member mounted on the first member and also angularly movable about said axis, one of the members having a recess and the other of the members having a projection extending into said recess, such that angular movement of the first member from a rest position, with said projection at one end of the recess, can effect angular movement of the second member from one rest position to another rest position, return movement of the first member to its rest position taking up lost motion between the members and resulting in said projection being disposed at the other end of the recess.

f- Preferably the first member is lower and the second member is a bolt. Desirably the projection is on the follower and the recess is in the inner peripheral surface of a circular,"ening through the hookbolt, in which opening part of the follower is received to mount the hookbolt thereon.

rhe invention will now be desbribed, byway of example, with reference to the accompanying drawingsi in which:

Figure 1 is a schematic interior view of a locking mechanism of the invention., Figure 2 is a reduced scale, non-schematic view corresponding to Figure Figures 3 and 4 are respectivaa-Wosite end views of the mechanism of Figure 2, Figures 5 and 6 are a view end and a side view respectively of a Ofee iw-_first follower of the locking nnism, to an enlarged scale, Figures 7 and 8 are a side A d a view of one end respectively of a second follower of the locki i ",chanism, also to an enlarged scale, Figures 9 to 11 are a plan view, a view of one side, and a view of the other side respectively of a hookbolt of the locking mechanism, to an enlarged scale, Figures 12 and 13 are respectively a plan view and a side view of a link of the mechanism, to an enlarged scale, Figure 14 is a side view of a spring bolt actuator of the mechanism, to an enlarged scale, Figures 15 to 18 are respectively a plan view, a side view, a view of one end and a view of the other end of a spring bolt lath of the mechanism, to an enlarged scale, Figures 19 to 21 are respectively a plan view and a side view of a deadlock element, and a side view of a deadlock tumbler element of the mechanism, to an enlarged scale, Figures 22 and 23 show respectively a plan view and a side view of a drive link of the mechanism, with part of Figure 23 being shown in section, and Figures 24 to 27 respectively show alternative forms of locking mechanism casing, cover, spring bolt latch lath and deadlock element.

A locking mechanism of the invention is shown'in Figures 1 and 2 in an almost, but not entirely completely assembled form. As will be appreciated, a casing 10 of the mechanism would normally be closed by a generally rectangular cover (not shown) of fairly conventional form, the cover being provided with appropriately shaped openings to receive various components and elements upstanding from the assembly shown in Figures 1 and 2. Moreover whilst the mechanism could possibly be used with only a latchbolt and deadbolt (to be described) extendable from and retractable into the casing 10, the locking mechanism would normally be used to form the central unit of a conventional multi-point lock, particularly a three-point lock, in which a slidable rod or bar is moved upwards or downwards through the central unit to extend or release locking members, such as boi"- the upper and lower ends of the lock.

Normally the three point lock at the outer edge of a pivoted door, with upper and lower bolts being extendable into respective associated keepers of the door frame.

As shown in Figures 1 to 4, thcUsing 10 is of generally conventional, rectangular form, being provickon its base with a plurality of upstanding fixing stumps 11 for securementof the above mentioned cover to close the open side of the casing vieibd in Figures 1 and 2. Add it ional ly, a hollow cylindrical sleeve 12 Auced diameter spigot parts at its respective ends is received n the rectangular faces of the casing with the spigots received inited respective cylindrical openings in the respective opposite sides casing. The sleeve thus assists in securing said cover, which to "--one side of the casing, to the remainder thereof. It will however be ap iated that any other form of means for connecting the cover to the remainder of the casing can be used.

ANFLY- journailed between the casing sides towards the upper end of the casing is a top follower 13, shown in detail in Figures 5 and 6. The follower is generally cylindrical with a square section opening 14 centrally therethrough. However externally the follower is stepped outwardly between its opposite end parts which form spigots 15, 16 respectively of equal diameters. The spigots are received in respective associated circular holes in the opposite sides of the casing so that the follower is angularly movable within the casing about its central axis. As shown best in Figure 6, the spigot 15 which is journalled in the opening in the base part 17 of the casing shown in Figures 1 and 2 is of greater axial extent than the spigot 16 at the opposite end of the top follower, the difference between the axial extent of the two spigots being made up by way of an enlarged diameter portion 18 which forms an annular shoulder at its junction with the spigot 16. Disposed between the spigot 15 and the portion 18 of the top follower 13 is a central portion 19 which is of greater external diameter than the portion 18, both of the portions 18 and 19 being centred on the central axis of the follower. A generally radialiy extending rib 20 of substantially semi-circular shape extends parallel to the axis of the follower on the external surface thereof as shown best in Figure 6, the rib extending from the junction of the portions 18 and 19 over a length of the spigot 15 equal to the longitudinal extent of the portion 18. As shown in Figures 1, 2 and 5, the rib extends radially outwardly beyond the periphery of the central portion 19 so as to form a projection from the follower for a purpose to be described.

At a position angularly spaced around the periphery of the central portion 19 from the rib 20 is a projecting tail part 21 which is integral with the central portion 19. This tail part 21 is generally rectangular, but has its outer surface formed as an arc struck about the central axis of the top follower 13. The tail part 21 extends over approximately 300 of arc, in this example, being spaced around the central portion 19 at its centre, by approximately 1200 from the centre of the rib 20.

Pivotally mounted on the top follower 13 for angular movement relative thereto is a link 22 in the form of a hook bolt, shown in Figures 9 to 11. One end of the hook bolt, which is lowermost as shown in use in Figures 1 and 2, has a part circular pery, the centre of the circular part being shown in Figure 9 as the axis V. A part circular opening 23 is formed in this lower part of the hook bolt the opening 23 having the axis '0' as its centre. The internal diameterof the opening 23 is slightly larger than the external diameter of the spigot 15 so as to allow that spigot to pass through the opening 23 so as to mount the hook bolt pivotally on the top follower, this lower part of w- is thus disposed between the central portion 19 of the top fol lower and the base part 17 of the casi ng, adjacent which the outer surface of the-Jower part of the hook bolt is disposed. This lower part of the hook bobas a thickness corresponding substantially to the axial extenW the rib 20 over the spigot 15.

As shown in Figure 9, the ope" 23 is, around part of its inner surface, extended generally radiallyou,'--iiyto form an angular recess 24. The radially outer boundary of theiess is itself an arc struck about the axis '0' whilst the upper end of th 55ss, as viewed in Figure 9, is disposed AV, radially. However the opposi,-lower end of the recess is off-radial, being arranged to lie horizontoy when the hook bolt is in its retracted position in the locking mechar4M, as shown in Figure 2, with the locking mechanism being vertical. MM arranged on the inner part of the spigot Arkof the top follower, the hook bolt has the rib 20 projecting into the recess 24, as shown in Figures 1 and 2, and with the hook bolt in its retracted position shown in Figure 2, the normal, rest position of the top follower is such that the rib 20 is at the bottom of the recess 24 and thus in engagement with the off-radial surface at the bottom of the recess, so that. as will be described, angular movement of the top follower in an anti-ciockwise direction as viewed in Figure 2, will cause the rib to push on this lower recess surface and thus pivot the hook bolt out of an opening in the front of the casing to its extended position. The recess extends over approximately 650 of arc, in this example, and since this is very much greater than the angular extent of the rib 20, it will be appreciated that movement of the hook bolt is possible relative to the top follower. In other words there is arranged to be lost motion between the top follower and the hook bolt in at least one direction of relative movement, as will be described hereinafter.

As shown best in Figures 9 to 11, a central part 25 of the hook bolt extends generally at right angles to the extent of the lower part whilst at the upper end of the central part a top part 26 of the hook bolt extends at right angles to the central part from the opposite side thereof to the lower part. Finally a hook part 27 forming the upper free end of the hook bolt extends from the top part 26 at right angles to lie generally parallel to the central part 25, so that the parts 25 to 27 generally form a shallow Ushape. As can be seen from Figures 9 to 11, the lower part is in a first plane, whilst the central part is cranked so that the top part, including the hook part, lies in a plane parallel to, but spaced from, the plane of the lower part of the hook bolt. In other words, as previously described, whereas the lower part lies adjacent the base part of the casing, this upper 9_ part of the hook bolt is disposed more centrally of the casing. At the forward junction of the lower and central parts of the lock bolt, on the inside surface of the hook bolt, is a spigot 28, from a flat end surface of which a short cylindrical peg 29 ends, this peg lying normal to the plane of the lower part of the, bolt. As shown best in Figures 1 and 2, the position of this peg relative to the axis '0' is such that it lies adjacent the interior of the front of the casing 10 so as, as will be explained, to protrude through a slot in a drive link which is arranged to operate upper and lower lockin-g units of the three-point lock.

journal led in the casing betweqn7 respective opposite sides thereof, at a position below the top follower43, is a bottom follower 30, the axis of rotation of the bottom followerMing in a common plane with the axis of the top follower, said plane bek.Wparaliel to the front and rear sides of the casing. The bottom follower, -n in detail in Figures 7 and 8, is of similar form to the top followet13 having end spigots 31, 32 respectively received in respective associated, openings in the base 17 and cover of the casing respectively in the sameymy as with top follower 13. However instead of the portions 18 and 19 of the top follower, the bottom follower has a single enlarged diameter central portion 33 between said end spigots, the diameter of the po"n 33 being slightly greater than that of the portion 18 of top followerzwtA rib 34 of substantially the same form as rib 20 extends across the of portion 33 and for part of spigot 3 1, the extent of the rib across theqt 31 being slightly less than the extent of the rib 20 across spigot 1 the top follower 13, a square section opening 35 extends through th^llower 30 being centred on the longitudinal rotational axis of t-.follower. In the same way that the link 22 is pivotally mounted on the top follower 13, a link 36 is pivotally mounted on the bottom follower 30 as shown best in Figures 1 and 2.

The link 36, shown in detail in Figures 12 and 13, is generally platelike in side view, one end portion of the link having a part circular periphery, opposite sides of the plate then converging together to form a relatively narrow opposite end at which a cylindrical projection 37 is formed at one side of the plate, a short, reduced diameter cylindrical peg 38 extending centrally from a flat end surface of the cylindrical projection 37 in a similar manner to the projection of the peg 29 from the spigot 28. Formed in the larger end of the link 36 is a generally cylindrical opening 39 of exactly the same form as the opening 23 in link 22, the opening 39 having the same axis as that of the part circular outer peripheral surface of the link at this larger end thereof. Additionally the opening 39 is provided with a recess 40 again of exactly the same form as the recess 24, with the upper end of the recess being radial and the lower end being off-radial and lying horizontally, as shown in Figures 1 and 2, in the unlocked position of the locking mechanism shown in those figures, and with the bottom follower in its normal rest position.

Pivotally mounted on a fixing stump 11 disposed adjacent the sleeve 12 is a latchbolt actuator 41. This is disposed in the plane of the central portion 19 and is in the form of an elongated finger having an ear 42 at its upper extremity, at one side of its pivot, and a foot 43 at its lower extremity at a position just below the bottom follower 30. The actuator extends over the side of the link 36 from which the projection 37 extends, having its side which faces the cover of the casing disposed below the level of flat end surface of the projection 37 from which the peg 38 extends.

The foot 43 is arranged to engage a flat surface 44 of an upstanding projection 45 on a latchbolt lath 46 which is linearly slidable into and out of the casing in a conventional manner by way of a cylindrical peg 47 on a face of the lath adjacent the inner face of the base part 17 of the casing, this peg running in a lateral elongated slot 48 (Figure 1) in the casing base, the lath extending through an associated rectangular opening in a front surface of the casing in a conventional manner. To the front of the lath, again in a conventional manner, is attached a latch bolt head 49, which can be reversible. At its lowerend, the lath has a gating 46a for reception of a conventional lock cylinder-tam to retract the latchbolt into the casing by the use of a key at either side of the door, as will be explained hereinafter.

i n the opposite face of the lath.10- that f rom wh ich the peg 47 extends, i s an elongated slot 50 parallel tolIffie slot 48 in the casing, the slot 50 receiving a cylindrical peg 51 pioJecting from one face of a deadlock element 52. The deadlock elenmt 52 is of generally conventional form defining a gating or lower ope 53 thereof which has chamfered entry and exit faces for reception ofnventional cam of a cylinder lock, so that operation of the lock by a conventional key wi 11 move the cam into and out of said opening so as to raise a deadlock tumbler element 54 against a spring, not shown, rved in a recess 55 in the deadlock element 52. As is generally cntional, the tumbler element has a part 56 received in a slot in the baW'---part 17 of the casing, the slot being configurated so that said part do-only pass along the slot when it is lifted relative to the deadlock elemekinst said deadlock element spring. In other words only when the cawof the cylinder lock is operated to lift the deadlock tumbler element against its spring is it possible for the cam to slide the deadlock element forwardly or rearwardly in the casing, for a purpose to be described. As shown in Figures 19 and 20, a further cylindrical peg 57 is provided with the deadlock element 52, the peg 57 being on the opposite side face thereof to that from which the peg 51 projects. As will be described, this peg 57 is intended to enter a recess in a slidable drive link of the mechanism so as to lock said link in a particular position to be described.

Finally as far as the structure of the mechanism is concerned, Figures 1 to 4 and 22 and 23 show a drive link 58 which acts as a common link between both of the followers and their respective associated links 22 and 36. In addition, as will be described, this common drive link 58 can be locked in an extended position upon deadlocking of the latch bolt and itself extends or retracts the secondary locking units of the three-point lock. As can be seen from Figures 1 to 4, the drive link 58 is in the form of an elongated generally rectangular flat strip or bar, normally of metal. The bar is longer than the casing and is arranged to extend through openings in the upper and lower end faces thereof. The bar is arranged to be slidably disposed relative to the casing for linear sliding movement adjacent the front face thereof just below the separate cover.

As shown in Figures 22 and 23, a central part of the drive link is formed with a pair of spaced elongated slots 59, 60 respectively which are each arranged at an angle of approximately 45' to the longitudinal extent of the link with it being intended that the link is disposed as shown in Figures 1 and 2, with the upper end of each slot adjacent the front face of the casing. The spacing part of the slots 59, 60, is such that the peg 29 of the hook bolt 22 is received into the slot 59, whilst at the same time the peg 38 of the link 36 is received into the slot 60, with the drive link being supported on the respective flat end surfaces of spigot 28 and projection 37. In the position shown in Figures 1 and 2, the pegs 29 and 38 are received at the respective lower ends of the slots, with the link extending further from the top of the casing than from the bottom of the casing. The side of the 1 i nk wh ich is towards the cover of the casi ng 10 is provided with three spaced rectangular projections 61 formed as pressings out of the plane of the link. These arereceived through associated respective rectangular slots in the cover, the slots being of much greater extent than the length of the projection 61-1o, as to allow for sliding movement of the link relative to the housing. Shruilarly the cover is provided with a keyhole slot corresponding to that shome in the base part 17 to allow insertion through the housing of a conveMional cylinder lock. Finally with regard to the drive link 58, it can be sinthat in its inner side surface just beyond the slot 60 and remote from slot59, there is a lateral recess 62 which is generally rectangular with a part cylindrical closed inner end surface. As will be described in detail, slid' movement of the drive link to extend its associated secondary loc ing peg 57 on the deadlock ele moved by operation of the to lock the drive link against Although not shown in the dra s, a latchbolt spring, normally in the 9 form of a coiled compression- would be received in the casing with its one end against the insidei--M rear face of the casing and its opposite end received in a recess 45a --"---ding into projection 45 from the face C M thereof opposite the face 44. rdingly the spring acts so as normally will bring this recess in line with the mr- so that as the deadlock element is _r lock this peg enters the recess 62 so as movement.

AW to bias the latchbolt to its extended position out of the casing as shown in Figures 1 and 2, with the peg 51 at the inner end of the slot 50, also as shown, when the deadlock element 52 is in its retracted position at the right hand inner side of the housing.

Operation of the locking mechanism will now be described, firstly where the operating members at the inside and outside of the door are connected to the top follower and the bottom follower respectively, and secondly where the operating members at opposite sides of the door are both connected to the top follower.

Thus in the first arrangement, operating members such as lever handles are connected to the top and bottom followers respectively, there being conventional spring loading of these handles so that after operation they normally return to their rest positions in which they lie horizontal relative to the lock casing as shown in Figures 1 and 2. The connection will normally be by way of a conventional square spindle extending from the handle through the square opening in the associated follower. With the arrangement shown in the drawings, it is intended that with the lock mechanism fitted at a conventional hinged door, for example a front door of a house, the top follower will, as described, be associated with the inside handle, and the bottom follower associated with the outside handle. Figures 1 and 2 show the locking mechanism in its retracted state. The hook bolt 22 is thus retracted into the housing and the drive link 58 is in its retracted position which, in this embodiment, corresponds to the drive link extending to a greater extent from the top of the housing than from the bottom thereof. In this arrangement the pegs 29 and 38 of the links 22 and 36 respectively are at the lower ends of their associated -is- slots 59, 60 and the ribs 20 and 34 of the followers 13 and 30 respectively are horizontal and at the lower ends of the respective recesses 24 and 40 in engagement with the off-radW surfaces of said recesses. The deadlock element 52 is in its retracted state, but, as described, the latchbolt is biased to extend out of the casing with the foot 43 of the latchbolt actuator 41 being in engagement with the surface 44 of the projection 45. With this arrangement the ear 42 of the actuator 41 is in the path of the tail part 21 of the top follower and would be engaged by it upon clockwise angular movement of said top follower. Such movement will not affect link 22 due to the lost motion between said components.

Accordingly in the condition illustrated, downwards movement of the inside handle will cause clockwise angular movement of the top follower with consequential engagement of the tail part 21 against the ear 42 of the latchbolt actuator 41. Accordingly the latchbolt actuator will pivot in an anti-clockwise direction so th,-- foot 43 in engagement with the projection 45 of the latchbolt will cause the latchbolt to be retracted into the casing against the force- of its spring so that the door can be opened from the inside. Releof the inside lever handle causes it to be returned to its horizontal posit-M under its spring biasing, the latchbolt also returning to its extended ion under its spring bias with the actuator 41 being returned to 1% position shown in Figures 1 and 2. It wi 11 be noted that corresponding downwards, i.e. clockwise angular movement of the outside hanand thus of the follower 30 will have no effect on the latchbolt which v4,,,.thus remain extended into its associated door frame keep. Latchbolt retraction from outside the door is only possible by key operation, as wM be described.

M As previously mentioned, the drive link 58 will have connected to its respective opposite ends associated further links and/or actuator members so as to operate the upper and lower locking means of the three point lock of which the locking mechanism shown in Figures 1 to 4 represents the central unit thereof in a known manner. The upper or lower secondary unit can merely be a vertical shoot bolt, or it can be arranged that sliding movement of the drive link will operate upper and/or lower slide or swing bolts to cooperate with associated keeper means at the door frame in the conventional manner.

To operate the three point lock from inside of the door, it is necessary to move the inside operating handle upwardly, i.e. anti-clockwise. This causes the rib 20 bearing on the lower surface of the recess 24 to force the hook bolt to pivot anti-clockwise and thus to swing out of the casing so that its hook end 27 will be received in its corresponding associated keeper part in the door frame. Moreover the pivotal outwards movement of the hook bolt 22 causes its associated peg 29 to push downwardly on the drive link so that the peg travels along the lower surface of the slot 59 forcing the drive link to slide downwardly, as viewed in the figures, through the casing until the hookbolt is fully extended, this corresponding to a position of the drive link where its recess 62 is opposite, i.e. aligned with, the peg 57 on the deadlock element 52. This sliding of the drive link similarly causes an anti-clockwise pivoting of the link 36 about the bottom follower 30 by virtue of the engagement of the peg 38 in the slot 60, the peg 38, like the peg 29 being moved along its associated slot in the drive link. It will be appreciated that the lost motion between the recess 40 and the rib 34 enables the link 36 to move relatively to the follower 30 whilst the follower remains static, so that in other words, the outside operating lever handle of the door remains horizontal whilst the inside handle is moved angularly upwardly. Accordingly this movement of the inside handle causes sliding of the drive link so that it projects from the housing more at the bottom than at the top of the housing, this movement actuating, i.e. extending, the upper and lower secondary units of the three point lock. Thus by operating the inner handle in this way the three locking units are operated, so that there is 'locking' by way of the hook bolt 22 at the central unit and also at each of the upper and lower secondary units. As will be ded, similar operation of the outer handle also operates the three locking units.

To deadlock these bolts in their extended positions, it is necessary to actuate the cylinder lock by means of a conventional key. Normally thiswould be from the outside of the door. as will be described. although inside operation is also possible. In the usual manner, operation of the key will cause the lock cylinder cam to lift the deadlock tumbler element, enabling the deadlock elemeritto be moved linearly to the left as shown in Figures 1 and 2. This causm-ihe peg 51 to engage the left hand end of the slot 50 so as to deadlock #Watchbolt against inwards retraction. Moreover this leftwards movement of the deadlock element 52 causes its peg 57 to be received in the rs 62 in the drive link thereby also effectively deadlocking that lintw-d thus deadlocking the hook bolt 22 and both of the secondary lolts. To remove this deadlocking, it is necessary to actuate the cylinx,",k in the reverse direction so as again to lift the deadlock tumbler eknt 54 so as to be able to move the deadlock element 52 to the right until it reaches its Figure 1 position, where again the latchbolt can he retracted inwardly and the drive link returned to its Figure 1 retracted position by moving the inner handle AME angularly downwardly in a clockwise position with the rib 20 engaging against the radial upper surface of the recess 24, so that inward swinging of the hook bolt causes its associated peg 29 to move in its slot 59 and raise the drive link to its retracted position. Once the position in Figure 1 is again reached, the latchbolt can again be retracted inwardly by normal downwards operation of the inner handle.

The outside handle, connected via a conventional square spindle to the bottom follower 30, can be moved angularly upwardly, i.e. anticlockwise, from the position shown in Figure 1, such movement causing the rib 34 in engagement with the lower surface of the recess 40 to pivot the link 36 anti-clockwise and thus slide the drive link to its retracted position, in the same way as previously described upon pivotal movement of the link 22. It wi 11 be appreciated that when the 1 i n k 3 6 causes si id i ng of the cl rive 1 i n k 58, such sliding automatically causes pivoting of the hook bolt 22. Accordingly it will be clear the operation of the outside handle in this manner will cause the three bolts of the three point locking system again to be extended so as to lock the door in its frame. Similarly it will be appreciated that operation of the key, now normally from the outside, will cause the deadlock element 52 to be moved so that its peg 57 is again received in the recess 62 of the drive link so as again to deadlock all the three locking bolts of the three point locking system, as well as deadlocking the latchbolt. It will also be appreciated that it is possible for the hookbolt 22 to pivot whilst the inside operating handle remains horizontal by virtue of the lost motion arrangement between the rib in its oversized associated recess 24.

Again deadlocking can only be released by operation of the key so as to move the deadlock element 52 to its right hand position shown in Figures 1 and Z, this releasing its peg 57 from the recess 62 thereby allowing the outside handle to be angularly moved downwardly. This causes the rib 34 to engage the radial upper surface of the recess 40, thereby pivoting the link 36 clockwise and raising the drive link 58 so as to release each of the three locking bolts of the three point locking system and again allowing normal retraction of the latchbolt as required. As mentioned, latchbolt retraction from outside the door is by key operation only, i.e. by means of further turning of the key, with the cylinder lock cam entering the gating 46a to retract the latchbolt, to allow opening of the door from outside. It will be appreciated that with this arrangement, the outside end of the top fol lower and the i nside end of the bottom fol lower wi 11 be blanked off.

In the second arrangement, where both of the operating members are connected to the top follower, the operation steps described for the inside handle of said first arrangement are now identically possible for the outside handle also. Accordingly, with the door held closed by the extended latch bolt, it can be opened by downward movement of either handle, since now for both of them, such action withdraws the latch bolt. Similarly, upward movement of either handle causes extension of the three bolts of the system by virtucof the shding of the link 58. Turning of the key, by one revolution, frominside or outside of the door wi I I now deadlock the link 58, and thus the three bolts and the latchbolt.

To release the deadlocking, it is firstly necessary to turn the key through one revolution, normally from outside of the door, to gain entry therethrough, but possibly from inside of the door if, for example, the door has been deadlocked from the inside at night. This turn of the key removes the deadlocking, thereby allowing either handle to be moved downwardly so as to effect upward sliding of the link 58 and thus withdrawal of the three locking bolts, with continued downward movement of the handle withdrawing the latchbolt to allow opening of the door. Although unnecessary, but as an alternative to handle operation withdrawing the latchbolt, it will be appreciated that after withdrawal of the three locking bolts, it would be possible to withdraw the latchbolt by operating the key again (from either side of the door), in the same manner as for latchbolt retraction from outside in the first arrangement.

It will be appreciated that the construction is particularly simple in requiring only a few parts by virtue of the drive link 58 acting as a common link between both followers, the connection from each follower to the drive link being direct by virtue of a single link member, as compared to previous prior art devices where a complex multiplicity of linkages has been required between a follower and the drive bar or rod which actuates the secondary units of the three point lock. The single drive link is also conveniently adapted to be deadlocked by the same mechanism which deadlocks the latchbolt. The mechanism is thus an improvement upon known devices by virtue of its simplicity and thus ease of production and by virtue of being less expensive to produce. Instead of two operating handles being connected to the respective followers, only a single operating member, normally at the inside, but possibly at the outside of the wing, could be provided. The follower not used could then be blanked-off in a convenient manner. Moreover the mechanism of the invention could be provided with only a single follower instead of with the two shown, thus allowing for only the second arrangement described, or for an arrangement with one follower and one operating member only.

Another aspect of the present invention relates to the convenient way in which lost motion is provided for between each follower and its link which connects movement of the follower to the drive link. As can be seen. in each case the lost motion is provided by way of a cut out in which a projection engages, with the projection being much smaller angularly than the cut out, so that a certain amount of angular movement of the link relative to a static follower is possible so that the link can move whilst the associated handle of the follower remains in its rest position whilst the handle associated wfth the other follower is being manipulated. It will be appreciated that this isa particularly convenient way of providing the lost motion. Howver instead of the recess being in the link and the rib on the follower, the, ib could instead be provided on the interior of the opening of the IlkL-this rib extending into a recess provided in an outer peripheral surface qf Me follower.

Whilst one basic form of a locking mechanism of one aspect of the invention has been described "-nbefore,, Figures 24 to 27 show alternative components used i her, modified embodiment of said one aspect of the invention. Inparticular in this arrangement, the latchbolt is moved to extend b further amount, for example 3mm, from its normal extended position, when the deadlock element is itself extended towards the front of tWnlechanism casing by key operation.

Figure 24 shows a casing 63 of4Jrnilar form to casing 10, having a slot 64 equivalent to slot 48 and a sloto equivalent to the slot in which part 56 L of the tumbler element is received. The casing has a cover 66, shown in Figure 25, which is formed with a slot 67, of identical form to slot 65, but arranged to lie, in use, just above it, in the direction of the top of mechanism as viewed in Figures 24 and 25. Between the slot 67 and the conventional opening 68 for reception of a cylinder lock are two elongated lateral slots 69, 70 respectively.

The latchbolt lath 71 shown in Figure 26 is of somewhat similar form to the lath 46, but instead of recess 45a for one end of the latchbolt compression spring, the latch 46 is formed with a projecting cylindrical peg 72 at its inner rear end to receive said one end of the spring. Adjacent the peg 72, but on the side face of the lath facing the cover 66, in use, can be a short, small upstanding peg, which, in use, engages the cover to minimise/prevent any tendency for the lath to tilt in the casing. On the opposite side face of the lath, adjacent the upper edge thereof and approximately mid-way between the front and rear ends of the lath is a projection 73 having straight sides and rounded ends, and sized to slide in slot 64 in the casing 63 to guide the latchbolt.

In the middle of the lath is a rectangular opening 74, and the lower edge surface of the lath is formed with an opening having chamfered/curved cam entry and exit faces, the opening forming a gating 75 of similar form to, and for the same purpose as, gatings 46a and 53 previously described.

Figure 27 shows a deadlock element 76 of somewhat similar form to deadlock element 52. However the element 76 is of greater thickness and has a platform 77 on the surface of its main body part which faces the cover 66 in use. A front end of this platform is in the form of a rectangular nose 77a which is sized to be received in a correspondingly shaped rectangular recess in the drive link, which is similar to the drive link 58, but where said rectangular recess replaces the more inwardly rounded recess 62.

The element 76 has a gating 79, equivalent to gating 53, with a cylindrical recess 79 replacing recess 55. JThe forward leg of the gating carries a projection 80 which is received in slot 70 in the cover, whilst a projection 81, of the same form as projection 73, is carried on the platform 77 in longitudinal alignment with thwgating 78, and is received in slot 69 in the cover. The projections 80 an thus guide sliding movement of the element 76 in the casing.

On the opposite side of the mahn body part from the platform 77, and at the front thereof, is formed a @ally rectangular projection 82 disposed with its longer sides parallel to-Ihe adjacent leading face of the element.

Said longer sides are dimensky just less than the width of the opening 74 into which the projection received, so as to link the deadlock element 76 to the latchbolt Ia". During normal latchbolt retraction and extension, with the deadWelement stationary at the right hand side of the casing, as in Figure 1, nger sides of the opening 74 slide back and forth past the stationary 0ion 82. Normal outward latchbolt extension is limited by the rind end of the opening 74, as viewed in Figure 26, engaging against prion 82.

The deadlock tumbler 54 is N0iced by a modified tumbler, not shown, which is of similar form., but h" 'upper' leg longer than its 'lower' one, the upper leg extending into Mgating slot 67.

In use, these modified components are arranged together to operate in a similar manner to either of the two arrangements described with reference to Figures 1 to 23. However when the key is operated, from inside or outside, to move the deadlock element from its Figure 1 position, following movement of the drive link fully to extend the hook bolt, the initial deadlock element movement causes the projection 82 to move towards the front of the casing. This allows the latchbolt spring to move the lath 71 in the same direction until the latch projection 73 reaches the end of its slot 64, whereupon the latchbolt can extend out no further. This additional outward movement of the lath, and thus of the latchbolt is, for example, 3mm, and provides additional security to the mechanism. Such extra movement also ensures that the gating 75 is clear of the gating 78 of the element 76 when the key is operated to release the deadlock by moving the element 76 from its extended to its retracted position.

Towards the end of its retraction movement, the deadlock element, by way of its projection 82, again engages the right hand end of the opening 74, and thereby pulls the bolt lath, against its spring, into the casing by the 3mm movement described, so as to leave it in its normal extended position. In this position the gating 75 of the lath is correctly disposed to allow latch bolt retraction by a second turn of the key, normally from outside the door. It is of course arranged that when the nose 77a of the deadlock element is received fully in the recess in the drive link, the projection 82 engages the left hand end of the opening 74, so as deadlock the latchbolt, in its additionally extended state, against inwards force. Thus the latchbolt and hookbolt are deadlocked, as, in effect, is the drive link.

Claims (41)

1. A locking mechanism for a movable wing comprising a follower for the connection thereto, in use, of an operating member at one side of said wing, a link connected directly between the follower and a link slidable between first and second positions, angular movement of the follower in one direction being arranged to effect sliding of said slidable link through movement of its associated connected link, and means for retaining said slidable link in one of its first and second positions.

2. A locking mechanism as claimed in Claim 1, wherein said slidable link is arranged to operate, in use, at least one secondary locking unit.

3. A locking mechanisrnAs claimed in Claim 2, wherein said slidable link is arranged to opeMe upper and lower secondary locking units by means of actuator conents connected to opposite ends of the slidable link respectively.

4. A locking mechanism 95 claimed in Claim 2 or Claim 3, wherein the slidable link is a flat bar wto- is slidable adjacent a face of a casing of the locking mechanism, which forms a front of the casing when it is fitted at said wing, in use. W-7

5. A locking mechanism&-'claimed in Claim 4, wherein said bar extends from opposite ends of casing.

6. A locking mechanism --ciaimed in any one of Claims 1 to 5, wherein the slidable link has one part of a recess and projection arrangement for retaining said slidable link in said one of its first and second positions.

7. A locking mechanism as claimed in Claim 1, including a casing from which a latchbolt is biased normally to extend.

8. A locking mechanism as claimed in Claim 7, wherein said means for retaining said common link in one of its first and second positions is locking means, which, when actuated, also retain said latchbolt against inward movement towards the casing from its extended position.

9. A locking mechanism as claimed in Claim 8, wherein the locking means is a slidable deadlock element, a first projection and recess arrangement of the deadlock element and the latchbolt respectively or vice versa retaining said latchbolt against said inward movement, in use, and a second projection and recess arrangement of the deadlock element and the slidable link respectively or vice versa retaining said common link in its said one position.

10. A locking mechanism as claimed in Claim 9, wherein said first projection and recess arrangement is formed by a projection on said deadlock element received in a siot in a lath of the latchbolt.

11. A locking mechanism as claimed in Claim 9 or Claim 10, wherein said second projection and recess arrangement is formed by a recess in a side surface of the slidable link and a projection on said deadlock element which is received in said recess in the link when the link is in said one position and the deadlock element has been slidably moved to retain said latchbolt against said inward movement.

12. A locking mechanismas claimed in any one of Claims 9 to 11, wherein slidable movement of the deadlock element is possible, in use, between extended and retracted positions in said casing, in which positions it is held against movement by a deadlock tumbler element.

13. A locking mechanism as claimed in Claim 12, wherein, in use. a cylinder lock is fitted in the ca%, actuation of which causes a cam of said lock to lift said tumbler element and slidably move said deadlock element between its extended and retracted positions.

14. A locking mechanism as claimed in Claim 12 when dependent upon Claim 10, wherein whe deadlock element is in its retracted position its projection is at an of said slot in the lath so as to prevent the spring bias acting on the lathbolt moving it to extend further from said casing, and part of said lalt engages said casing also to prevent said further extension upon ment of the deadlock element to its extended position.

15. A locking mechanisrnts claimed in Claim 12 when dependent upon Claim 10, wherein whenjj#ve deadlock element is in its retracted position its projection is at anc 4-nd of said slot in the lath so as to prevent spring bias acting on the latchhM-Moving it to extend further out of said casing, whilst engagement belOn part of the latchbolt and said casing allows said further movement,W-that upon movement of the deadlock element to its extended position the latchbolt moves to extend further from the casing.

16. A locking mechanism as claimed in any one of the preceding claims, wherein said link connected directly between said follower and the slidable link is in the form of a bolt extendable from and retractable into a casing or said casing of the locking mechanism upon angular movement of said follower in respective opposite directions.

17. A locking mechanism as claimed in Claim 16, wherein said bolt is a hook bolt.

18. A locking mechanism as claimed in any one of Claims 1 to 6, wherein movement of said follower in a direction which effects sliding of said slidable link to the other of its first and second positions from that in which it can be retained therein retracts into a casing or said casing of the locking mechanism a latchbolt which is biased so that it normally extends from the casing.

19. A locking mechanism as claimed in any one of Claims 7 to 15, wherein movement of said follower in a direction which effects sliding of said slidable link to the other of its first and second positions from that in which it can be retained therein retracts said latchbolt into said casing.

20. A locking mechanism as claimed in Claim 18 or Claim 19, wherein said follower has a projection which, when said follower is so moved, acts, in use, upon an actuator which engages said latchbolt to effect retraction thereof.

21. A locking mechanism as claimed in any one of the preceding claims, wherein the direct connection between said link and said slidable link is by means of a peg and slot.

22. A locking mechanism as claimed in any one of the preceding claims, wherein there is lost motion between said follower and said link.

23. A locking mechanism as claimed in Claim 22, wherein the lost motion is provided by angular movement of a projection on said follower in a recess provided in said link. -

24. A locking mechanism-as claimed in Claim 23, wherein said link is mounted on said follower for pivotal movement in respective opposite directions when said follower is,,moved angularly with said projection at opposite ends of said recess respectively.

25. A locking mechanism, claimed in any one of the preceding claims, wherein a single folloln the form of said follower only is provided, for connection, in us-k_---thereto at respective opposite sides of said wing of two operating murs.

42% '1 operating member at the other

26. A locking mechanism,-iaimed in any one of Claims 1 to 25, comprising a second follower f"e connection thereto, in use, of an of said wing, and a second link connected directly between t-- ond follower and said slidable link, angular movement of the secoliower in one direction being arranged to effect sliding of said slidabl-11-1- through movement of said second IM- link.

1 - AW-

27. A locking mechanism as claimed in Claim 26, wherein there is lost motion between said second follower and said second link.

28. A locking mechanism as claimed in Claim 27, wherein the lost motion is provided by angular movement of a projection on said second follower in a recess provided in said second link.

29. A locking mechanism as claimed in Claim 28, wherein said second link is mounted on said second follower for pivotal movement in respective opposite directions when said second follower i s moved angularly with said projection at opposite ends of said recess respectively.

30. A locking mechanism as claimed in any one of Claims 26 to 29, wherein angular movement of either said follower or said second follower in the opposite direction, in use, effects sliding of said slidable link to the other of its first and second positions provided said slidable link is not retained in said one of its first and second positions.

31. An arrangement of two relatively movement members comprising a first member angularly movable about an axis, a second member mounted on the first member and also angularly movable about said axis, one of the members having a recess and the other of the members having a projection extending into said recess, such that angular movement of the first member from a rest position, with said projection at one end of the recess, can effect angular movement of the second member from one rest position to another rest position, return movement of the first member to its rest position taking up lost motion between the members and resulting in said projection being disposed at the other end of the recess.

32. An arrangement as claimed in Claim 31, wherein said second member can be moved between its rest position other than by angular movement of said first member such movement of the second member taking up said lost motion.

33. An arrangement as claimed in Claim 31, wherein return angular movement of the second member to its one rest position is effected, in use, upon angular movement said first member with its projection at said other end of the recess, return movement of the first member thereafter to its rest position taking up said lost motion.

34. An arrangement as claimed in Claim 31 or Claim 33, wherein said recess is in the inner periffieral surface of a circular opening through said second member.

35. An arrangement as clomed in Claim 34, wherein the first member is a follower and the second member is a bolt.

36. An arrangement as claimed in Claim 32, comprising a slidable link,, sliding movement of whi6, in use, can effect said movement of the second member other than by ^'ular movement of the first member.

c,

37. An arrangement as cWrned in Claim 36, wherein said second member is a link connected to said slidable link.

111W INW-

38. An arrangement as claimed in Claim 37, wherein the second link is connected to said slidable link by means of a peg and slot.

39. A locking mechanism including an arrangement of two relatively movable members as claimed in any one of Claims 31 to 38.

40. A locking mechanism substantially as hereinbefore described, with reference to, and as shown in Figures 1 to 25 or Figures 26 to 29 of the accompanying drawings.

41. An arrangement of two relatively movable members substantially as hereinbefore described.