WO2003078770A1

WO2003078770A1 - Bolting mechanism

Info

Publication number: WO2003078770A1
Application number: PCT/GB2003/001105
Authority: WO
Inventors: Bernard John Viney
Original assignee: Surelock Mcgill Limited
Priority date: 2002-03-15
Filing date: 2003-03-17
Publication date: 2003-09-25
Also published as: AU2003215746A1; GB0206181D0; GB2386393A

Abstract

There is disclosed a bolting mechanism, for example to secure a door. The mechanism includes one or more rotatably mounted swing bolts. Each swing bolt has a face oblique to the plane of rotation such that, during rotation towards an engaged position, the oblique face tightens against an opposing surface of the doorframe. The oblique face may be provided by a taper of the end of each swing bolt the taper being in a direction radially away from, tangential to, or both radially away from and tangential to the axis of rotation of each swing bolt.

Description

BOLTING MECHANISM

The present invention provides a bolting mechanism adapted to retain an active leaf within a frame or with respect to a passive leaf. In particular, but not exclusively, the invention relates to such a bolting mechanism adapted to provide tightened closure of a leaf within a frame or with respect to a passive leaf. In a variety of situations a need exists to bolt a door, window or other leaf within a frame in such a manner that a substantially airtight or watertight ^■ seal is achieved around at least a part of the leaf. This is the case, for example, on passenger ships in which a passenger cabin has its own door to an exterior balcony or similar outdoor space which is open to rain and sea spray. If the door does not close against the frame sufficiently tightly then water may penetrate into the cabin, requiring frequent and expensive maintenance. Such a cabin door will typically be provided with one or more elastomer seals fixed about one or both of the edge of the door and the frame. However, without sufficient compression of these seals, , especially if the seals become worn or damaged, water seepage may still occur.

It would therefore be desirable_, to provide an improved bolting mechanism, which can preferably be retrofitted to such doors if required, and which enables such a door to be sufficiently tightly closed to prevent water seepage. At the same time, it would be desirable if such a mechanism could incorporate a latch arrangement for every day use, for example when tight closure of the door is not essential.

The present invention addresses these and other problems of the related prior art.

Accordingly, the present invention provides a bolting mechanism adapted to retain an active leaf within a frame or with respect to a passive leaf, comprising: one or more rotatably mounted swing bolts, each swing bolt having a distal end being moveable between an engaged position in which the distal end projects from the leaf, and a disengaged position, the distal end of each swing bolt having a face oblique to the plane of rotation of the swing bolt such that, during rotation towards the engaged position, the face tightens against an opposing surface of the frame or passive leaf.

Typically, the active leaf may be a hinged door closeable within a frame. Generally, the frame, or> frame and adjacent edge of a passive leaf, will have a principal plane in which the active leaf lies when closed. Preferably, the plane of rotation of the swing bolts lies substantially in this principal plane.

Preferably, the one or more rotatably mounted swing bolts are provided on the edge of the leaf distant from or opposite to a hinged edge. The opposing surface of the frame or passive leaf against which the swing bolt tightens is preferably provided by an inside edge of an aperture within the frame or passive leaf, typically provided by a keep, latch plate or similar component. As the swing bolt moves towards the enga.ged position, the oblique face of the swing bolt bears upon the opposing surface causing the leaf to close more tightly within the frame. In this way, any elastomer seal provided between the leaf and the frame is compressed. To achieve this effect, the plane of rotation of each swing bolt is preferably substantially the same as the principal plane of the active leaf.

In the case wherein two doors or other leaves are provided within a single frame, one of the leaves may be a passive leaf which, on securing the leaves, is secured first, while the other leaf may then be an active leaf which is subsequently secured against the passive leaf. The bolting mechanism of the invention may be used to secure the active leaf with respect to the passive leaf, by providing one or more of the described swing bolts along the edge of the active leaf which is adjacent, when closed within the frame, to an edge of the passive leaf.

Preferably, the oblique face of each swing bolt is provided by a taper of the distal end of the swing bolt. For manufacturing convenience, or for providing an easily reversible mechanism or bolt component, each swing bolt may be tapered on both sides. Alternatively, one face of the distal end of the swing bolt may lie substantially in the axis of rotation of the swing bolt, only the other face being tapered.

The direction of the taper of the distal end of each swing bolt may be such that the distal end narrows in a direction radially away from, or tangential to the axis of rotation of the swing bolt. Preferably however, the direction of narrowing of the taper is both towards, in a rotational sense, the engaged position of the swing bolt in a tangential direction and radially away from the axis of rotation, preferably in the region of 20° to 70°, and more preferably in the region of 30° to 60° between these two extremes.

The oblique face of the swing bolt may be omitted, for example in combination with one or more of the features set out below, which may instead be combined with other types of translationally or rotationally operating bolts. A hook bolt or non- tightening swing bolt may, for example, be provided in place of one or more of the oblique faced swing bolts. Preferably, the bolting mechanism comprises a latch bolt having a distal end, the latch bolt being slidable between an engaged position in which the distal end of the latch bolt projects from the active leaf, and a disengaged position. The latch bolt is preferably operable to move between its engaged and disengaged positions when the swing bolts are in the disengaged position, so that the latch bolt can be used as an every day or preliminary means to fasten the leaf. Preferably, the latch bolt is biassed towards the engaged position by means of a latch bias, and is also preferably provided with an oblique face which causes the latch bolt to move to the disengaged position as the leaf is pushed shut within the frame, thereafter springing back to occupy a latch keep set in the frame.

Preferably, the swing bolts and the latch bolt are moveable between their respective engaged and disengaged positions by means of a common actuating member, such as a conventional door handle. Preferably a first range of motion of the common actuating member moves the swing bolts between their engaged and disengaged positions while a second range of motion, distinct from the first range of motion, moves the latch bolt between its engaged and disengaged position. Typically, the common actuating member is provided by a door handle of a type which may be used to provide sufficient leverage to engage all of the swing bolts securely.

. Preferably, . the common actuating member and the swing and latch bolts are coupled by means comprising a boss rotationally mounted on a common axis with one of the swing bolts, hereinafter referred to as the master swing bolt. In order to allow a single common actuating member to operate the latch bolt when the swing bolts are in the disengaged position, the rotation of the boss is preferably coupled to the rotation of the master swing bolt by a first lost motion coupling. Preferably, the rotation of the boss relative to the master swing bolt is biassed in a rotational sense towards the engaged position of the master swing bolt by a master swing bolt bias, for example by means of a tensioned helical spring or other resilient member, advantageously acting between the boss and the master swing bolt. Preferably, the rotation of the boss is coupled to the movement of the latch bolt by a second lost motion coupling. Advantageously, this second lost motion coupling may be complementary to the first lost motion coupling such that the latch bolt does not move at the same time as the swing bolt. Conveniently, the second lost motion coupling may comprise an armature acted on by an element of the boss.

Preferably, the bolting mechanism comprises at least two of the above-mentioned rotatably mounted spring bolts, wherein the spring bolts are moveable between their respective engaged and disengaged positions by a common drive mechanism. Conveniently, this common drive mechanism may comprise a link bar. Preferably, this link bar is provided with a plurality of pins, each pin being located so as to engage with a suitable aperture, recess or other driving surface of one of the swing bolts as it rotates.

Preferably, the bolting mechanism further comprises a locking mechanism arranged to prevent movement of the swing bolts when in their respective engaged positions, (and optionally when in their respective disengaged positions) . This locking mechanism may be provided by a locking plate translatable between an unlocked position, and a locked position in which the locking plate interferes directly or indirectly with the rotation of the master swing bolt. In particular, the locking plate may interfere with the rotation of the above-mentioned boss, for example by engaging with a first recess in a surface of the boss when the master swing bolt is in the engaged position. If the common actuating member, or handle, acts on the swing bolts and latch bolt by acting on the boss then such an arrangement will serve to lock both the swing bolts and latch bolt simultaneously .

Advantageously, an over-lock arrangement may be provided to control the movement of the locking plate. Preferably, the over-lock and the locking plate are driveable by a common drive member. Such an over-lock serves to prevent illicit or accidental movement of the locking plate. Preferably, the common drive member is arranged to engage in a driving notch provided in the locking plate, to thereby drive the locking plate between the locked and unlocked positions. Preferably, the over- lock comprises an over-lock arm positioned adjacent to the driving notch such that the common drive member engages both the over-lock arm and the drive notch at the same time.

Preferably, the over-lock comprises a bias, such as a spring, and is arranged to lock the locking plate in either of the locked or unlocked positions until the over-lock arm is moved by the common drive member against the action of the bias. Conveniently, the over-lock arrangement may be provided by a spring, a portion of which forms the over-lock arm and another portion of which catches in suitable apertures or notches to lock the locking plate.

Preferably, the locking plate and over-lock are driven by a key accepting means such as a key cylinder provided with a rotatable tang or cam follower, providing the above common drive member.

The invention also provides a leaf within a frame, the leaf being provided with a bolting mechanism as described above and the frame being provided with one or more suitable opposing surfaces. Alternatively, the frame may be provided with such a bolting mechanism which operates by the swing bolts engaging with opposing surfaces provided on the leaf. Embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings, of which:

Fig. 1 illustrates a bolting mechanism according to the invention comprising a master swing bolt assembly and two slave swing bolt assemblies coupled to operate together;

Fig. 2 is an end view of the bolting mechanism shown in Fig. 1; Fig. 3 illustrates in detail the master swing bolt assembly of Fig. 1 with a cover removed, and in a locked and bolted configuration;

Fig. 4 is a perspective view of the over-lock spring shown as 92 in Fig. 3; Fig. 5 shows the master swing bolt assembly of

Fig. 3, but in an unlocked and unbolted configuration;

Fig. 6 illustrates the internal workings of one of the slave swing bolt assemblies shown in Fig. 1, with a cover removed and in a bolted configuration; Fig. 7 is a plan view of a swing bolt of the master or slave swing bolt assemblies illustrated in Figs. 3, 5 and 6;

Fig. 8 shows a cross section along A—A of the swing bolt shown in Fig. 6; and Fig. 9 illustrates a catch plate or keep, to be mounted in the frame or passive leaf,_, which provides the opposing surface against which the swing bolt of Figs . 7 and 8 tightens on movement towards the engaged configuration . Referring now to Fig. 1, there is shown a bolting mechanism adapted to retain an active leaf within a frame or with respect to a passive leaf. The bolting mechanism comprises a master swing bolt assembly 10, and two slave swing bolt assemblies 12. The master swing bolt assembly 10 comprises a casing 14 with a bezel plate 16 and bezel plate pack 18 mounted on one side of the casing 14. Thus, the casing 14 is adapted for acceptance within an edge of a door or other leaf in a mortice configuration, with the bezel plate 16 lying flush with the leaf edge.

A boss 20 is rotationally mounted within the casing 14 and presents a square or spline section bore for accepting a complementarily sectioned shaft to which a handle may be attached in order to rotate the boss 20. A master swing bolt 22 is rotationally mounted on the same axis as the boss and is configured to move from a disengaged position in which it is retained within the casing and an engaged position (as shown in Fig. 1) in which a distal end of the master swing bolt 22 protrudes from the casing through an aperture in the bezel plate 16 and bezel plate pack 18 to be accepted in a keep or other aperture of an adjacent frame or passive leaf.

A latch bolt 24 is also mounted within the casing 14, and is slidable within an aperture of the bezel plate 16 and bezel plate pack 18 to similarly move between an engaged and a disengaged position.

A key cylinder 26 is provided partly or wholly within the casing 14 in order to be able to lock the master swing bolt 22 and latch bolt 24 in a chosen position. Each slave swing bolt assembly 12 is of similar construction to the master swing bolt assembly 10, providing a slave swing bolt 32 rotationally mounted within a casing, except that no latch bolt or key cylinder is provided. The master swing bolt assembly 10 is linked to each slave swing bolt assembly 12 by a link bar 28. The link bar is of U-shaped section with a part of the casing of each swing bolt assembly contained within the U-section. A link pin 30 fastened between the two walls of the U-section of the link bar passes through a slot in each swing bolt assembly casing, coupling translation of the link bar to rotational movement of each swing bolt. In this way, rotation of the master swing bolt 22 drives rotation of each slave swing bolt 32.

Fig. 2 shows the bolting mechanism of Fig. 1 in end view so that the two slave swing bolts 32, master swing bolt 22 and latch bolt 24 are visible end-on.

This is the view of the mechanism which would be seen when the mechanism was mounted in mortice configuration within the edge of a door, although when so mounted the link bar 28 would typically be hidden. Fig. 3 shows the master swing bolt assembly 10 in more detail, with the link bar 28 and a top plate of the casing 14 removed. It can be seen that the casing 14 comprises a base plate 50 bracketed on one side for attachment to the bezel plate 16 and bezel plate pack 18. The removed top plate (not shown) is screwed to a pair of casing pillars 54 provided on the base plate 50 and both the top plate and base plate are provided with apertures for accepting the key cylinder 26 and the boss 20. Both the top plate and the base plate 50 are also provided with a link bar pin slot 55 within which the link bar pin 30 may slide to couple the rotation of the master swing bolt 22 to translation of the link bar 28 (not shown) .

The boss 20 is provided with a projecting spring anchor tang 56 and a projecting armature tang 58. The spring anchor tang 56 couples the rotation of the boss to the rotation of the master swing bolt 22, while the armature tang 58 couples the rotation of the boss to translation of the latch bolt 24 via an intermediate armature 60.

The spring anchor tang 56 resides within a spring recess 62 formed within the master swing bolt 22. The spring anchor tang 56 is provided with a limited amount of freedom of movement within the spring recess 62, thereby providing a rotational lost motion coupling between the boss 20 and the master swing bolt 22. This lost motion coupling is biassed by a master swing bolt spring 64 which is located within the spring recess 62. The master swing bolt spring 64 is anchored at one end by a spring anchor pin 66 attached to the master swing bolt 22, and at the other end to the spring anchor tang 56. The master swing bolt spring 64 thereby biasses the rotation of the boss 20 with respect to the master swing bolt 22 in the sense of rotation towards the engaged position of the master swing bolt 22. Because of the lost motion coupling, even when the master swing bolt 22 is in the disengaged position the boss 20 can rotate further in a clockwise direction, in the sense of the view of ^■ Fig. 3. During this further rotation, the armature tang 58 engages with one end of the armature 60, which is rotationally mounted on an armature pin 68. The other end of the armature 60 is located within a notch provided in the latch bolt 24. As the boss 20 continues to rotate clockwise and the armature tang 58 bears upon one end of the armature 60, the rotation of the armature 60 causes a translational movement of the sliding latch bolt 24, which thereby retracts to its disengaged position.

The latch bolt 24 slides within an aperture in the bezel plate 16 and bezel plate pack 18, guided by a latch bias pin 70. The latch bias pin 70, which is held -securely between the base plate. 50 and top plate of the casing 14 is accepted within a slot 72 in the latch bolt 24. The movement of the latch bolt slot 72 relative to the latch bias pin 70 serves to guide the latch bolt 24, while a compressible latch bolt spring 74, acting between one end of the latch bolt slot 72 and the latch bias pin 70 serves to bias the latch bolt 24 towards its engaged position.

A locking plate 80 is provided so as to be slidable between a locked position (shown in Fig. 3) and an unlocked position (shown in Fig. 5) , driven by a cam follower 82 bearing within a drive notch 84 of - li ¬

the locking plate. Rotation of the cam follower 82 is effected by insertion and turning of a key within the key cylinder 26. A latching of the locking plate 80 in either the locked or unlocked positions is effected by a bale catch 85 comprising a small ball bearing pressed against the locking plate 80 by a spring contained within a hollow bale catch pillar 89. When in the locked position the small ball bearing engages with a first aperture 90 or recess provided in the locking plate, and when in the unlocked position, with a second aperture 91 or recess provided in the locking plate.

The movement of the locking plate 80 between the locked and unlocked positions is further restrained by means of an over-lock, which comprises an over-lock spring 92. The over-lock spring 92 lies beneath the locking plate 80 in the view of Fig. 3, and is shown as a broken line where not visible in this view. The over-lock spring 92 is coiled around the bale catch pillar 89. A tail 93 of the spring projects away from the bale catch pillar 89 to bear against the lower of the two casing pillars 54. An arm 94 of the spring projects away from the bale catch pillar 89 in the direction of motion of the locking plate 80 between its locked and unlocked positions. The arm 94 passes directly beneath the drive notch 84 in the locking plate. The tip of the arm 94 first dips to contact the back plate 50, then rises to engage one of two over-lock notches 95 provided in an edge of the locking plate 80. A perspective view of the over-lock spring 92 is shown in Fig. 4.

When the cam follower 82 bears within the drive notch 84 of the locking plate 80 it simultaneously bears on the arm 94 of the over-lock spring 92, pressing the tip of the arm out of a first of the over-lock notches 95. The cam follower 82 drives the locking plate 80 to its new position and, as it continues to rotate bears away from the arm 94 of the over-lock spring 92, the tip of which moves back to enter the second of the over-lock notches 93.

The arm 94 of the over-lock spring 92 therefore catches in a first of the over-lock notches 93 when the locking plate 80 is in the unlocked position, and in a second of the over-lock notches 93 when the locking plate 80 is in the locked position, in either case preventing unwanted sliding motion of the locking plate 80. Because the tip of the arm 94 of the over- lock spring 92 is only released from either over-lock notch 93 by action of the cam follower 82, the over- lock spring 92 thus helps prevent accidental or illicit movement of the locking plate 80. When in the unlocked position the locking plate 80 does not interfere with the motion of either the master swing bolt 22 or the latch bolt 24. When moved to the locked position the locking plate 80 engages with one of two locking recesses provided on the boss 20. A first of the locking recesses 86 is provided so that an arm 87 of the locking plate 80 can engage with the first recess and prevent movement of the boss when the master swing bolt 22 is in the engaged position. Optionally, a second locking recess 86 may be provided such that the arm 87 of the locking plate 80 can engage with this, second recess and prevent rotation of the boss when the master swing bolt 22 is in the disengaged position. Because the boss is used to drive both the master swing bolt 22 and the latch bolt 24, locking the rotation of the boss by means of the locking plate arm 87 prevents further movement of both the master swing bolt 22 and the latch bolt 24.

The master swing bolt 22 is provided with an open driving slot 88. A part of this driving slot 88 is always located between the two link bar pin slots 56 in the base plate 50 and top plate of the casing 14, whether the master swing bolt 22 is in the engaged - Im ¬

position, the disengaged position, or somewhere in between. Movement of the master swing bolt 22 between the engaged and disengaged positions causes a surface of the driving slot 88 to bear on the link bar pin 30, driving it along the link bar pin slot 56. This motion couples the rotation of the master swing bolt 22 to translation of the link bar 28, thus driving the slave swing bolts 32 shown in Figs. 1 and 2.

Whereas Fig. 3 illustrates the master swing bolt assembly 10 in a bolted and locked configuration, with both the master swing bolt 22 and the latch bolt 24 in their engaged positions, Fig. 5 illustrates the master swing bolt assembly 10 in an unbolted and unlocked position, with both the master swing bolt 22 and the latched bolt 24 in their respective disengaged positions. The sequence of events which leads from the configuration of Fig. 3 to the configuration of Fig. 5 will now be described. For the purposes of this discussion it is assumed that the master swing bolt assembly is installed in the edge of a door or similar leaf in a mortice configuration, that a square section shaft passes through the centre of boss 20 and is connected to a door handle. It is also assumed that the door is initially closed within a frame, with the master swing bolt 22 and latch bolt 24 engaged within suitable apertures of a keep mounted within the frame, such as the keep illustrated in Fig. 9.

A key is inserted into key cylinder 26 and rotated clockwise in the sense on the view of Fig. 5. As the key rotates, so does cam follower 82. The cam follower engages the locking plate drive notch 84, at the same time deflecting the arm 94 of the over-lock spring 92, the tip of which is thereby released from a first of the over-lock notches 95. This allows the locking plate 80 to slide downwards to the unlocked positron. With continued clockwise rotation the cam follower 82 eventually disengages from the locking plate notch 84 when the locking plate 80 has reached its lowest position (that shown in Fig. 5) . The corresponding release of the arm 94 of the over- lock spring 92 allows the tip of the arm to engage with the second over-lock notch 95, locking the lock plate 80 in the unlocked position. Downward movement of the locking plate 80 disengages the locking plate arm 87 from one of the locking recesses 86 of the boss 20, freeing the boss 20 and allowing it to rotate. Clockwise rotation of the door handle and shaft cause clockwise rotation of the boss 20, in the sense of the view of Fig. 5. The spring anchor tang 56 thereby exerts an increased tension on the master swing bolt spring 64, and, when fully extended, the boss 20 connects with the master swing bolt 22, causing it to rotate in a clockwise direction thereby withdrawing from the keep in the doorframe towards its disengaged position.

As the master swing bolt 22 moves from the configuration shown in Fig. 3 towards the configuration shown in Fig. 5 a surface of the master swing bolt 22 lying within the driving slot 88 bears upon the link bar pin 30 urging it down the link bar pin slot 55, thus driving a translational movement of the link bar 28 (not shown) and causing simultaneous rotation of the slave swing bolts 32_. illustrated in Fig. 1 to their respective disengaged positions.

When the master swing bolt 22 reaches the disengaged position, as illustrated in Fig. 5, the handle can be used to rotate the boss further in a clockwise direction, because of the lost motion arrangement provided by the spring anchor tang 56 being moveable within the master swing bolt spring recess 62. Thus the boss is rotated clockwise further, against the tension of the master swing bolt spring 6 . The armature tang 58 comes into contact with one end of and proceeds to drive the armature 60, and as the armature 60 rotates about the armature pin 68, the other end of the armature drives the latch bolt 24 towards its disengaged position, against the action of the latch bolt spring 74. The master swing bolt 22, the latch bolt 24 and the slave spring bolts 32 are now all completely retracted to their disengaged positions and the leaf may be opened.

Release of the handle causes the boss to rotate in an anti-clockwise direction. This rotation is driven by the tension in the master swing bolt spring 64 acting on the spring tang anchor 56 and the pressure in the latch bolt spring 74 causing the latch bolt 24 to act on armature 60 which in turn acts on the armature tang 58. This anti-clockwise motion of the boss 20 allows the latch bolt 24 to move back to the engaged position, while the movement of the spring anchor tang 56 is taken up within the master swing bolt recess 62 so that the master swing bolt 22 remains in the disengaged position. To bolt the door again the reverse of the appropriate steps of the above process occur. In particular, once the leaf is closed within the frame and the latch bolt 24 is in the engaged position, rotation of the handle in the anti-clockwise direction, in the sense of the view of Fig. 5, causes the spring anchor tang 56 to bear on. an edge of the master swing bolt spring recess 62, driving the master swing bolt 22 in an anti-clockwise direction into the keep in the frame. Constructional details of a slave swing bolt assembly 12 is illustrated in Fig. 6. Although the much simpler functionality required of a slave swing bolt assembly 12 means that the components used in its construction may be considerably less complex than the equivalent components of the master swing bolt assembly 10, it may be more cost effective to construct each slave swing bolt assembly 12 using as many components common with the master swing bolt assembly 10 as possible. For this reason, the boss 20 and swing bolt 32 shown in Fig. 6 are of precisely the same construction as those of the master swing bolt assembly 10 shown in Fig. 3, although the spring anchor tang, armature tang and locking recesses of the boss, as well as the spring anchor pin and master swing bolt spring recess have no function in the operation of the slave swing bolt assembly. The slave swing bolt 32 is driven by translation of a link bar pin 30, carried on the link bar 28 (not shown), within a link bar pin slot 56. The link bar pin 30 bears on a surface of the slave swing bolt 32 presented by the driving slot 88 to thereby rotate the slave swing bolt 32 either towards its engaged or towards its disengaged position.

The structure of the casing of the slave swing bolt assembly, including a base plate, a top plate, two pillars, a bezel plate and a bezel plate pack is essentially the same as that of the master swing bolt assembly illustrated in Figs. 3 and 5.

Constructional details and particular features of the master swing bolt 22 and the slave swing bolts 32 will now be discussed with reference to Figs. 7 and 8. The layout of a swing bolt 22, 32 may broadly be divided into a proximal end 96, proximal to the axis of rotation of the bolt, and a distal end 98. The axis of rotation, which is shared with the boss 20 (not shown) , passes through the centre of an aperture 100 located at the proximal end 96. The distal end 98 is provided with an oblique face 108 which is oblique to the plane of rotation of the swing bolt. The driving slot 88, which bears on the link bar pin to couple with the motion of the link bar 28 (not shown) is at the proximal end 96.

A cross-section A— of Fig. 7 is shown in Fig. 8. It can be seen that the distal end 98 of the swing bolt is tapered. The narrowest point of the taper is at the leading corner 102 shown in Fig. 7. The leading corner 102 is the part of the swing bolt 22, 32 which first enters a keep or reaches the opposing surface of the adjacent frame or passive leaf. The broken line 104 in Fig. 7 is a line of constant thickness of the swing bolt, illustrating the furthest extent of the tapering of the distal end 98. It will therefore been seen that the tapering direction lies about halfway between the radial and the tangential with respect to the axis of rotation of the swing bolt, narrowing in a direction shown in Fig. 7 by arrow B.

Fig. 9 illustrates a typical keep or latch plate 106 which may be mounted flush with the inside surface of a frame or passive leaf so as to be in opposition with the bezel plate 16 of the master swing bolt assembly 10 when the leaf is closed. A similar keep with only a single rectangular aperture is preferably provided in the frame in respect of each slave swing bolt assembly 12. Each swing bolt assembly 10, 12 and corresponding keep 106 is mounted such that when the leaf is closed and a swing bolt 12, 22 is moved towards its respective engaged position the outer oblique face 108 of the swing bolt meets the corresponding edge 110 of the keep 106. As the swing bolt continues to rotate the oblique face 108 tightens against the opposing edge 110 of the keep, causing the leaf to close more tightly within the frame or against the passive leaf. If, for example, resilient seals are provided between the leaf and the frame then these are compressed by the tightening action, thus providing an improved seal.

It will be appreciated that a number of variations may be made in respect of the preferred embodiment described above. Although the bolting mechanism illustrated in Figs. 1 and 2 comprises one master swing bolt assembly and two slave swing bolt assemblies, the slave swing bolt assemblies, link bar and other linking means could be omitted or varied. For example, just one, more than two, or no slave swing bolt assemblies could be provided. The constructional details of the swing bolt assemblies may be varied. The locking and latch mechanisms could be implemented in a variety of ways or omitted altogether. For example, instead of the master swing bolt assembly described, an assembly similar in complexity to the slave swing bolt assemblies could be used. Although the figures show a bolting mechanism adapted for implementation in a mortice configuration, the mechanism could be surface mounted on a leaf, or otherwise arranged.

The swing bolt illustrated in detail in Figs. 7 and 8 can be modified in a variety of ways. Although an oblique face 108 is required in order to bear against an opposing surface of the frame or passive leaf in order to tighten the closure, this could be provided in a number of ways. For example, although both sides of the swing bolt are illustrated as carrying the taper in Fig. 8 this is largely for manufacturing convenience and instead only one side could carry the taper. Instead of providing a tapered distal end of the swing bolt, the distal end 98 could be provided by a region of substantially constant thickness which is nonetheless oblique to the plane of rotation of the swing bolt. The tapering discussed in connection with Figs. 7 and 8 is in a direction midway between the radial and tangential, with respect to the axis of rotation of the swing bolt, but other directions of tapering or inclination of the oblique face 108 could equally be used to achieve the desired effect. For example, tapering or inclination in just the tangential direction or in just the radial direction could be used. The various parts of the mechanism, including the locking and over-locking arrangements, the couplings between the swing bolt and the latch bolt, with the handle and between the master and slave assemblies may be used in isolation from the other parts, for example within different bolting mechanisms to that described as the preferred embodiment.

Instead of oblique faced tightening swing bolts, non-tightening, hooked, or other types of rotationally mounted bolts could be used. Alternatively, the handle could drive more conventional translationally acting bolts. Hooked swing bolts, with or without a tightening oblique face, could advantageously be used to secure one or two sliding doors. Finally, although the preferred embodiment has principally been described within the context of a hinged door to be closed within a frame, the invention may also be used in respect of other types of leaf to be closed within a frame such as a window, a removable wall panel, a trap door, or the active leaf of a pair of doors mounted within a single frame.

Claims

1. A bolting mechanism adapted to retain an active leaf within a frame or with respect to a passive leaf, comprising: one or more rotatably mounted swing bolts, each swing bolt having a distal end and being moveable between an engaged position in which the distal end projects from the leaf, and a disengaged position, the distal end of each swing bolt having a face oblique to the plane of rotation of the swing bolt such that, during rotation towards the engaged position, the oblique face tightens against an opposing surface of the frame or passive leaf.

2. The bolting mechanism of claim 1 wherein the oblique face of each swing bolt is provided by a taper of the distal end of the swing bolt.

3. The bolting mechanism of claim 2 in which the direction of narrowing of the taper of the distal end of each swing bolt is in a direction radially away from, tangential to, or both radially away from and tangential to the axis of rotation of the swing bolt.

4. • The bolting, mechanism of any preceding claim further comprising a latch bolt having a distal end, the latch bolt being translatable between an engaged position in which the distal end of the latch bolt projects from the leaf, and a disengaged position.

5. The bolting mechanism of claim 4 wherein the latch bolt is biased towards the engaged position.

6. The bolting mechanism of claim 4 or 5 wherein the swing bolts and the latch bolt are moveable between their respective engaged and disengaged positions by means of a common actuating member.

7. The bolting mechanism of claim 6 adapted such that a first range of motion of the common actuating member moves the swing bolts between their respective engaged and disengaged positions and a second range of motion of the common actuating member, distinct from the first range of motion, moves the latch bolt between its engaged and disengaged position.

8. The bolting mechanism of any of claims 4 to 7 wherein the common actuating member and the swing and latch bolts are coupled by means comprising a boss rotationally mounted on an axis common with the rotational axis of a master one of the swing bolts.

9. The bolting mechanism of claim 8 wherein the rotation of the boss is coupled to the rotation of the master swing bolt by a master swing bolt lost motion coupling, and the rotation of the boss relative to the master swing bolt is biassed in the direction towards the engaged position of the master swing bolt.

10. The bolting mechanism of either claim 8 or claim 9 wherein the rotation of the boss is coupled to the movement of the latch bolt by a latch bolt lost motion coupling .

11. The bolting mechanism of claim 10 wherein the latch bolt lost motion coupling comprises an armature.

12. The bolting mechanism of any preceding claim, comprising at least two of said rotatably mounted swing bolts, wherein the swing bolts are movable between said engaged and said disengaged positions by a common drive mechanism.

13. The bolting mechanism of claim 12 wherein said common drive mechanism comprises a link bar.

14. The bolting mechanism of claim 13 wherein the link bar comprises a plurality of pins, each pin being located to be engaged by a link bar driving surface of a respective one of said swing bolts.

15. The bolting mechanism of any preceding claim further comprising a locking mechanism arranged to prevent movement of the swing bolts.

16. The bolting mechanism of any of claims 4 to 7 further comprising a locking mechanism which comprises a locking plate slidable between an unlocked position and a locked position in which the locking plate interferes with the rotation of a master one of said swing bolts .

17. The bolting mechanism of any of claims 8 to 11 further comprising a locking mechanism which comprises a locking plate slidable between an unlocked postion and a locked position in which the locking plate interferes with the rotation of the boss.

18.. The bolting, mechanism of either of claims 16 or

17. further comprising an over-lock for controlling movement of the locking plate, arranged such that the over-lock and the locking plate are operated by a common drive member.

19. The bolting mechanism of claim 18 wherein the common drive member is arranged to engage in a driving notch provided in the locking plate to thereby operate the locking plate, and the over-lock comprises an over-lock arm adjacent to the driving notch, arranged such that the common drive member engages the over- lock arm during engagement with the drive notch.

20. The bolting mechanism of claim 19 wherein the over-lock comprises an over-lock bias, and is arranged to lock the locking plate in either of the locked or the unlocked positions until the over-lock arm is moved by the common drive member against the action of the over-lock bias.

21. The bolting mechanism of any of claims 16 to 20 wherein the locking plate is driven by key accepting means .

22. The bolting mechanism of any preceding claim wherein the plane of rotation of the one or more swing bolts is substantially aligned with the principal plane of the frame.