WO2022069901A2

WO2022069901A2 - Smoke damper

Info

Publication number: WO2022069901A2
Application number: PCT/GB2021/052546
Authority: WO
Inventors: Hans Nicholas PURDOM; Jeffrey Michael Jones; Martyn Francis KENNEALLY
Original assignee: Linear Building Innovations Limited
Priority date: 2020-10-01
Filing date: 2021-10-01
Publication date: 2022-04-07
Also published as: WO2022069901A3; GB2602440A; GB202015596D0

Abstract

A multi-point latching system for a smoke damper system comprising a motorised opening and closing mechanism (16) for a smoke damper (12) in a frame (14), and a multi-point latching mechanism which is mechanically connected to the motorised opening and closing mechanism such that as the motorised opening and closing mechanism (16) attempts to open the smoke damper (12) from a latched state, it unlatches the multi-point latching mechanism before then opening the smoke damper (12), and such that as the motorised opening and closing mechanism (16) attempts to close the smoke damper (12), it closes the smoke damper (12) before then latching the multi-point latching mechanism. The multi-point latching system has two rods (46) that get pulled in to latch outer latches (28). The rods (46) also operate a central latch (48).

Description

Smoke Damper

The present invention relates to a smoke damper, and in particular a motorised door used as a smoke control damper in a building for allowing automated opening and closing of the vent covered by the door. The vent may be a vent of a smoke stack or smoke shaft of the building, for example to resist venting of smoke between floor levels of a building, or for controlling smoke and air movement through the stack when required by the smoke control system of the building.

Motorised doors for opening and closing vents of a smoke stack or smoke shaft of a building are known in the art. See, for example, GB2552767. Mostly such doors are relatively small and thus are easily held closed in a smoke-tight manner by conventional door closing mechanisms, such as motorised opening and closing mechanisms.. As a result, the motorised opening and closing mechanism will typically be adequate to secure the door in a closed condition. However, with larger buildings, sometimes the smoke control design for the building demands a larger door. As a result, situations are arising where the motorised door is much bigger, such that the motorised opening and closing mechanisms can no longer compress the seal all the way around the door, leading to failure points in the smoke control system - e.g. where smoke can leak past the seal due to the tops or bottoms of the doors not being sealed properly by the smoke seal. As such smoke stacks or smoke shafts are commonly in multi-story buildings, there can be many such doors in a multi-storey shaft, whereby these doors can present a danger to people in the building..

The present invention seeks to provide a new form of smoke damper, or smoke damper closing and opening system, which can avoid or reduce this problem.

The present invention also seeks to provide a new latch mechanism for doors.

According to the present invention there is provided a smoke damper in the form of a door within a door frame, the door comprising a motorised opening and closing mechanism, and the door and frame between them comprising a multi-point latching mechanism which is mechanically connected to the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the door from a latched state, it unlatches the multi-point latching mechanism before then opening the door, and such that as the motorised opening and closing mechanism attempts to close the door, it closes the door before then latching the multipoint latching mechanism.

The present invention also provides a multi-point latching system for a smoke damper comprising a motorised opening and closing mechanism, and a multi-point latching mechanism which is mechanically connected to the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the smoke damper from a latched state, it unlatches the multi-point latching mechanism before then opening the smoke damper, and such that as the motorised opening and closing mechanism attempts to close the smoke damper, it closes the smoke damper before then latching the multi-point latching mechanism.

In some embodiments the multi-point latching mechanism comprises three latching units - an upper latching unit, a lower latching unit and a centre latching unit, each latching unit comprising a latch and a keep.

In some embodiments the multi-point latching system has two rods that get pulled in to latch outer latches (e.g. the upper latching unit and the lower latching unit). This is rather than the rods being pushed out to latch the outer latches, and rather than the use of a single rod to actuate both outer latches together.

In some embodiments the rods also operate a central latch as well (e.g. the centre latching unit).

In accordance with one aspect of the present invention latches of an upper and a lower latching unit are mounted onto the frame and keeps of the upper and lower latching units are attached to the door, the keeps of the upper and lower latching units facing their corresponding latches of the upper and lower latching units when the door is closed such that they can achieve the latched state. Usually the latches and keeps of the upper and lower latching units are provided at or near one or more edge of the door, and a corresponding (facing) part of the frame - i.e. the top and bottom edges, or a side edge, or a combination thereof. In some embodiments the upper and lower latching units are provided with retractable latches and fixed keeps.

In some embodiments a centre latching unit is provided at or near a centre of a side edge of the door and at the corresponding (facing) part of the frame, between upper and lower latching units.

In some embodiments the three latching units are connected together on the frame by connecting rods extending either side of a transfer box assembly that is connected to the motorised opening and closing mechanism.

In some embodiments a latch of the centre latching unit is on the door, and a keep of the centre latching unit is on the frame. In some embodiments the latch has a fixed tang.

In accordance with another aspect of the present invention the keep of the centre latching unit comprises at least one movable catch plate operable by the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the door from a latched state, it moves the at least one movable catch plate from a latch catching position to a non-catching position before then opening the door, and such that as the motorised opening and closing mechanism attempts to close the door, it closes the door before then moving the at least one movable catch plate from a non-catching position to a latch catching position.

In some embodiments the latch of the centre latching unit is a fixed latch on the door.

In some embodiments the at least one movable catch plate is a part of a sliding member that is operably attached to the transfer box assembly.

In some embodiments there are two moveable catch plates and both are movable by the motorised opening and closing mechanism - for example via the transfer box assembly.

In some embodiments the transfer box assembly has one or more actuator member for moving therein in response to interaction of the motorised opening and closing mechanism with the transfer box assembly, the actuator assembly being operatively connected to the at least one movable catch plate, the motorised opening and closing mechanism thus when operating being able to move the at least one movable catch plate by operation of the transfer box assembly.

In accordance with a further aspect of the present invention the transfer box assembly comprises a box and a slide assembly, the box being mounted on the frame and the slide assembly being located part in the box and part out to a side of the box, such that it can slide more or less into or out of the box, the part extending out to a side of the box being connected to the motorised opening and closing mechanism, the box and slide assembly each having at least one slot, the two slots being not parallel to one another, but being located so as to relatively intersect with one another through a movable but common perpendicular axis through a range of positions of the slide assembly relative to the box, the slots being for accommodating an actuator member such that as the slide assembly slides in and out of the box the accommodated actuator member slides along the slots to thus then move relative to the box and the slide member.

This further aspect of the present invention can be used with the preceding aspect by having the actuator member be one of the at least one actuator member of the preceding aspect, such that the movement of the actuator member is for moving the sliding member or at least one movable catch plate.

Preferably there are two pairs of such slots and two actuator members, such that it can move two movable catch plates.

In some embodiments the slide assembly is mounted within the box with one or more spring being provided to bias the slide assembly into a less-extended-out-of-the-box state, in which position the three latching units are all unlatched.

In some embodiments the two actuator members are each connected to one of the connecting rods such that the actuator member also operates the upper and lower latching units. In a preferred embodiment the connecting rods are pushed outwards relative to the transfer box assembly, each one towards its respective connected upper or lower latching unit, to unlatch the upper and lower latching units. In most prior art three point latching mechanisms, the connecting rods or members have to retract towards the transfer box to release the upper and lower latching units, which are commonly shoot bolts. This new direction of movement has the advantage that it allows a pair of the movable catch plates for the centre latching unit to be separated from one another (if those movable catch plates move with the connecting rods) so as to open the keep like a trapdoor, thus releasing even a fixed latch on the door. In some embodiments, therefore, the invention has two rods connected to a central latch that get pulled in to operate trap doors as a keep for the central latch.

Further, in most prior art three point latching mechanisms, the three latches are all on the door, and the three keeps are all in or on the frame, whereas with a preferred aspect of the present invention only the centre latch is on the door, and it can be fixed, rather than needing to be operated by a handle.

Further, in most prior art three point latching mechanisms, the transfer box assembly operates through use of the door handle or key. In a preferred aspect of the present invention it is instead operated by sliding movement of a slide assembly that can be operated by the motorised opening and closing mechanism.

In some embodiments, the or each of the upper and lower latches of the upper and lower latching units have a spring and trigger mechanism built in such that it or they can only be triggered to a latching state when the door is closed. This prevents out-of- turn movement of the connecting rods towards a latching state for the upper and lower latches prematurely moving the latches to their latching state, which might otherwise prevent the door from being closed properly by the motorised opening and closing mechanism.

With this arrangement, even if the slide plate of the transfer box is pulled out, out of sequence or timing, the latches at the top and bottom cannot throw prematurely in a manner that could block the closing of the door. In some embodiments a spring and trigger mechanism built into the or each of the upper and lower latches triggers the or each of the upper and lower latches to close as the door is closed into the frame, the or each of the upper and lower latches engaging with the or each of the upper and lower keeps upon that triggering of the upper and lower latches. In some embodiments, it is the engagement of a trigger of the spring and trigger mechanism with a part of the frame, or a part of the upper or lower keep, that triggers the upper and/or lower latch to close

In one example, as the door reaches the point at which the upper and lower latches can throw and engage in a first part of the keep, the keep itself can press on the trigger allowing the tang to be released and throw into the keep.

The engagement of the keeps by the upper and/or lower latches can be such that the latches themselves interact with the keeps, and due to their sprung design, pull the door fully closed, thus automatically improving or ensuring the engagement of the seal between the door and the frame near those latches, i.e. at the top and bottom of the door.

In some embodiments of the present invention, sprung latches are provided on the frame, operated by rods on the frame, that auto-spring into keeps on the door. In some embodiments this would be in conjunction with a drive mechanism of the motorised opening and closing mechanism (for example a chain push/pull mechanism) being on the door, rather than the frame. In some embodiments the sprung latches serve to draw the door into a fully closed state, if needed from an ajar state.

The presence of a trigger of this kind also helps to ensure that the release of the tangs into the upper and lower keeps is timed to occur only once the door is closed.

Such sprung tangs can also work in reverse to ensure that the tangs can be retracted before the movement of the door starts from a closed state towards an open state.

The combinations of the components of this mechanism thus can serve to create both the correct timing of actions between the door and the tangs of the active latches and the central trapdoor latch, and also to ensure the door always fully closes and latches no matter what movements the motorised opening and closing mechanism might cause to the transfer box assembly.

In some embodiments the motorised opening and closing mechanism is a chain push/pull mechanism such as those sold by Geze ®. These drive mechanisms comprise a chain of links that can push outwardly by extending the chain out of a housing, which chain can flex in one direction only, such that it stays strong if flexed the other way, but that can collapse back into the housing when retracted. In other words the chain has only one direction of flexibility when extended out of the housing due to the form of the links. It thus can push open the door by being extended from the housing, with the free end of the chain attached to the slide assembly, that pushing causing a pushing of the slide assembly into the box, thus keeping the upper and lower latching units unlatched, and the centre keep open, whereas when retracted it can pull the door closed and then pull the slide assembly more out of the box to activate the actuator members, and thus to move the connecting rods and catching plates, and the upper and lower latching units, to thus latch all the latching units once the door is closed. With the spring in the transfer box, the timing of the closing of the two catching plates can be controlled such that they only close behind the latch on the ends of the door once the door is closed. This is achieved by making the spring strong enough to resist the sliding out of the slide assembly from the box until the door closes against the frame, the fixed frame thus resisting further closing of the door and thus transferring any further movement of the chain into its housing into movement of the slide assembly relative to the box.

The present invention therefore provides a new arrangement for a motorised door and for the multi-point latching system.

These and other features of the present invention will now be described in greater detail, purely by way of example, with reference to the accompanying drawings, in which:

Figure 1 shows a front of a door in a frame in a wall prior to plastering over the frame, with various section lines AA, DD, FF marked thereon; Figure 2 provides an exploded perspective view of the rear of the door and frame of figure 1 ;

Figure 3 shows a cut through section through line AA of figure 1, with two highlighted areas B and C;

Figure 4 shows in more detail highlighted area B from figure 2;

Figure 5 shows in more detail highlighted area C from figure 2;

Figure 6 shows a cut through section through line DD of figure 1 , with two highlighted areas E and F;

Figure 7 shows a cut through section through line FF of figure 1, with one highlighted area G;

Figure 8 shows in more detail highlighted area E from figure 6; highlighted area F from figure 6 is simply a mirror image of figure 8

Figure 9 shows in more detail highlighted area G from figure 7;

Figures 10 and 11 show in more detail two bracket assemblies that each comprise one of the movable catch plates and a connector for a respective one of the connecting rods;

Figure 12 is an exploded perspective view of an embodiment of transfer box, comprising a box with a lid and a slide assembly for slidably mounting partially therein;

Figure 13 is a perspective view showing the slide assembly connected to an end of a chain drive, the transfer box in a door locking configuration;

Figure 14 is a perspective view showing the slide assembly sprung back into the box - for ease of reference the end of the chain drive has been detached from the slide assembly; Figure 15 is a perspective view of the rear of the door, in a top corner thereof, showing the bracket for attachment of the keep to the door, and showing also the latch for that keep’s latching unit and an end of an associated connecting rod.

Figure 16 is a perspective view of the rear of the door, in a bottom corner thereof, rotated for ease of annotation, showing the keep and latch for that other, lower, latching unit, this time seen from the other side to better show the latch - which is in a nonlatching configuration;

Figure 17 is a second perspective view of the rear of the door, in a bottom corner thereof, rotated for ease of annotation, again showing the keep and latch, this time in a latching configuration, with its sprung latch engaging with the keep; and

Figures 18 to 21 are pairs of views showing the movable catch plates of the sensor latching unit in part open and fully closed conditions, with figures 18 and 20 showing the assembly with the frame cover present, and figures 19 and 21 showing the assembly with the frame cover removed.

Referring first to figure 1, there is shown a wall 13 in an opening of which a frame 14 has been fitted, which frame houses a door 12. In this embodiment, the frame comprises top, bottom, left and right sides and the door is rectangular. Other shapes of door, and frames having a top and two sides can also be used with the present invention is the bottom can be replaced with a threshold, for example if the door is at floor height, rather than elevated above the floor.

As can be seen in figure 1 , and in more detail in figures 4, 5 and 8, the frame 14, in this embodiment, comprises folded metal sections with perforated flanges 140 that lie against plasterboard 116 lies over stud work 114 of the opening in the wall 13. These metal sections thus allow a minimalist installation of the frame 14 in the wall 13, by plastering over the perforated flanges 140 and the plasterboard 16 up to a reference corner 138 of the frame 14.

Referring next to figure 2, an exploded view the door, along with its multi-point latching mechanism 18 and its motorised opening and closing mechanism 16, plus the frame 14, plus also a draft or smoke seal 104, extending around the inside of the frame 14, around the door 12, is shown. As can be seen, door 12 is fitted into the frame to pivot around top and bottom hinge pins 98, 100, which hinge pins 98, 100 are located in top and bottom corners of the door 12 near a first edge 142 of the door 12. The opposite edge of the door - the free side edge 38 instead has attached thereto hardware relating to the motorised opening and closing mechanism 16 and parts of the multi-point latching mechanism 18. These parts, highlighted in dot-dash boxes in figure 2, include upper and lower keeps 26 for upper and lower latching units 20, 22 of, in this embodiment, a three point latching mechanism 18. The multi-point latching mechanism thus in this embodiment is a three point latching mechanism 18. These keeps will be described in greater detail with reference to later figures.

The third latching mechanism of the three point latching mechanism 18 is a centre latching unit 24, details of which are shown in figure 9, which will be discussed in further detail later on.

Still referring to figure 2, the remaining parts of the multi-point latching mechanism 18, i.e. those fitted to the frame, are highlighted in a dotted box. These comprise, from the bottom, a sprung lower latch 28, a connecting rod 46, a lower or bottom sliding member 54, a transfer box assembly 48, a top or upper sliding member 52, a second connecting rod 46 and a sprung upper latch 28. The upper and lower latches 28 are identical in this embodiment as they operate as a pair to engage the correspondingly identical, upper and lower keeps 26, which thus likewise operate as a pair of keeps. The only difference is that one of each pair faces upwards, whereas the other faces downwards. In this embodiment, therefore, the multi-point latching mechanism is designed to operate both the upper and the lower latching units at the same time, and thus it transfer box assembly 48 serves to move both connecting rods 46 simultaneously for operating those upper and lower latching units 22, 24.

The mechanism of this operation will be described in further detail below.

Powering the operation is the motorised opening and closing mechanism 16, which in this embodiment is in the form of a powered chain drive, as known from companies such as Geze ®. Such chain drives are usually provided for opening and closing pivotable windows, but can function likewise to open and close an unlocked door. The movement is achieved by pulling and pushing a chain out of an opening 144, which chain has a single freedom rotation, whereby it can provide a pushing force as well as a pulling force. Such a use is known in the art, for example from prior art document GB2552767. The present invention, however, incorporates that drive into operating the multi-point latching mechanism prior to opening the door and after closing the door.

As can be seen in figure 2, the transfer box assembly 48 is arranged to be fitted in a recess 102 provided in the frame 14. In this embodiment, as the frame is made of metal section, screws or bolts 108, in this embodiment four, are used to attach the transfer box assembly 48 to the frame. To allow lateral adjustment of the mechanism, however, in this embodiment the screws or bolts 108 fit in slots on projecting tabs or flanges 148 extending to the ends of the transfer box assembly 48, as can be seen in figure 12, for example.

Still referring to figure 2, the upper and lower latches 28 also get screwed to the frame, but instead at the areas 40, 42 highlighted in dotted lines. The recess hundred and two is instead located at the area 44 highlighted in dotted lines which sits between the areas 40, 42 the upper and lower latches 28.

Returning to figure 1 , three section lines A, D and F are provided. These refer to figures 3, 6 and 7 respectively. Those sections each show the walls 13 and the door 12, and each highlight specific areas of the frame and the surrounding components of the present invention.

Referring next to figure 3, area B is a downward and vertically facing section through a lower part of the side edge 38 of the door 12 and the adjacent frame component and is shown in enlarged form in figure 4. Area C is instead a downward and vertically facing section through a lower part of the first edge 42 of the door 12 and the adjacent frame component, and is shown in enlarged form in figure 5.

Figure 4 therefore shows the door 12 closed against the frame 14, compressing this Ell 104 therebetween. The frame 14 is mounted with its perforated flange 140 bearing against an outer layer of plasterboard 116, which plasterboard 116 is an outer layer of the wall 13. The plasterboard 116 attached to stud work 114, and on the other side of the stud work 114, an inner layer of plasterboard 116 is also provided. An inner face of the stud work 114 - facing into the opening formed by the stud work 114 - is faced with a further layer of building material, which may also be plasterboard, but is preferred to be part of the frame, and preferably a removable cover plate thereof. Between that further layer of building material or cover plate and the frame 14 an intumescent bead 112 can be fitted.

Instead of stud work, the frame can also be fitted to a block wall.

In this embodiment, the front of the door 12 is fitted flush with the reference corner 138 of the frame 14. This further assists with creating a minimalist appearance to the door in the wall.

To the rear of the door, a mounting bracket 146 is provided onto which the motorised opening and closing mechanism 16 is attached by its own bracket 110.

Due to the location of this section, figure 4 also shows the lower connecting rod 46 as it descends down to the lower latching unit 22.

Referring next to figure 5, again the wall 13 can be seen, this time the other side of the opening. Again the perforated flange 140 engages against the outer plasterboard 116, and the front face of the door 12 lies flush with the reference corner 138 of the frame 14. Being a view down to the bottom edge of the door, the bottom hinge pin 102 can be seen in the bottom corner of the door, and a security or dog bolt 118 can be seen extending out of the first edge 142 of the door 12 through a hole (not shown) in the frame 14.

As in the previous figure, and intumescent strip 112 can be seen between the frame 14 and a further piece of building material (or a cover plate of the frame) that extends between the stud work and the frame 14.

Referring next to figure 6, section DD is shown from figure 1. This figure, like figure 3, shows the wall 13 and the door 12, but also the motorised opening and closing mechanism 16 on the rear of the door 12. It also highlights two areas E and F, which are mirror images of each other as the upper and lower latching units 22, 24 are identical in this embodiment, albeit just arranged to face different, opposing directions - one at the top of the door and the other at the bottom of the door.

An enlarged view of area E is shown in figure 8.

Figure 7, like figure 6, is a further section through the door and wall of figure 1 through section FF. It highlights a single area G, and provides a downward view through the centre latch unit 24, an enlarged version of which is provided in figure 9.

Referring next to figure 8, an upper latching unit 20 is shown. From this figure, the door 12 can be seen to have attached at its top a bracket 106, which bracket is for attaching the keep 26 to the rear of the door. That keep 26 is for engagement by a tang 120 of the upper latch 28. As this view is schematic, that upper latch 28, which is attached to the frame 14, is only shown in free space in this view. Part of it is masked by the bracket 106 due to the angle of view.

This view again shows the intumescent seal 112 between the frame 14 and the wall 13. It also shows the perforated flange 140 against the front plasterboard 116 of the wall 13. It also shows the seal 104 against which the door 12 will press when closed. A schematic, the section of the seal 104 is shown unflexed despite the door being closed against it.

As can be seen in this view, the keep 26 for the tang 120 has a recess into which the tang 120 of the upper latch 28 can extend when sprung outward, as shown in this figure.

The connecting rod 46 connects to the upper latch 28 with a threaded connection in this embodiment. This is to allow adjustment of the length of the connecting rod during installation to ensure that the length can be compensated for any mis-positioning of the transfer box assembly 48 in the vertical direction.

Referring next to figure 9 and enlarged view of the transfer box assembly 48 and the centre latching unit 24, in section, is shown. This section, through line FF in figure 1, sits approximately in the middle of the second edge of the door 12. In this view, a fixed latch 32 can be seen for the centre latching unit 24, although where a handle is desired to be provided for the door, the latch 32 would not be fixed. It is also optional to provide a non-fixed latch if a manual override for this latching mechanism is required.

The centre latch 32 is provided on the bracket 146 between the door and the bracket 110 of the motorised opening and closing mechanism 16. In this embodiment it is located through an aperture therein. It is positioned to align with a trapdoor type keep 136, when the door is closed, which trapdoor type keep 136 will be described in further detail with reference to figures 10, 11 and 18 to 21.

From figure 9 is also to be noted that the transfer box assembly 48 which connects to the frame 14 on the side thereof opposite to the door, will become sandwiched against or closely adjacent to the wall upon installation of the frame. The transfer box assembly 48 is thus attached to the frame usually before installation of the frame in the opening of the wall, in the recess 102 provided therefore.

The transfer box assembly 48 has therein a control pin 124 along which a slide assembly 74 can slide in and out of the transfer box assembly 48, guided by upstand bearings 128 - four of which are shown in figure 12. Those upstand bearings 128 have slots or grooves in an edge thereof in which the edge of the slide assembly 74 sits. The slide assembly 74 is thus controlled to slide in and out of the transfer box assembly through a fixed plane and in a linear direction. During that sliding, a central slot through which the control pin 124 extends (between a base of a box 70 and the underside of a lid 72 of the transfer box assembly 48) governs the extent of movement of the slide assembly 74 is the control pin 124 will come to bear against the ends of the central slot at the extremes of that movement. The slide assembly 74 can thus only slide in and out to a limited degree.

Two further slots are provided parallel to that central slot, which further slots how’s a spring each, which springs 80 bias the slide assembly 74 into the transfer box assembly 48 so that by default the slide assembly 74 will take its innermost slid state. Such sprung returns are well-known in mechanical devices of this nature.

There also two inclined slots 76, 78 in the slide assembly 74. These two inclined slots 76, 78 cooperate via first and second actuator members 58, 68 with perpendicular slots 150 in the base of the box 70 and the lid 72 to create cammed sliding of the two actuator members 58, 68 in those perpendicular slots during the sliding of the slide assembly 74 in and out of the transfer box assembly 48. Those perpendicular slots 150 are perpendicular to the central slot. Although perpendicular, they may be inclined relative thereto if preferred, although by being perpendicular, the sliding of the actuator members 58, 68 ends up being in the vertical direction, and thus parallel to the connecting rods 46, which is optimum for the their function of moving those connecting rods 46.

Those actuator members 58, 68 are connected via bolts 60 and connectors 64, 66 to the connecting rods 46, as can be seen in figure 9, when considering combination with figure 10 (or 11). As can be seen, a bolt 60 extends through a movable catch plate 52, 54, and connects through a connector 64, 66 after washers 62 and then screws into the actuator member 58.

The driving movement of the slide assembly 74, the outside end thereof is connected to the motorised opening and closing mechanism 16, as shown in figure 13. For this purpose a connector pin 84 extend through a receiving tube 134 on the free edge of the slide assembly 74. In this embodiment, that receiving tube 134 has two parts with a gap 90 between them, in which gap 90 the chain and 92 can be accommodated and locked therein with the connector pin 84, which connector pin 84 extends through a hole 94 in the chain and 92. See for example figure 14 where the chain end 92 has been disconnected from the connector pin 84.

Referring next to figures 10 and 11, can be seen that the two actuator members 58, 68 connected to their respective connecting rods 46 ineffectively symmetrical manners, with the connector 64 of one of the arrangements having its connection end extending to the left, and the other with its connection end extending to the right. This can be seen further in figure 18 where the connection rods 46 with end connectors connected onto those connectors 64, 66 being shown.

Figures 10 and 11 also show wear plates 122 over which movable catch plates 50, 56 of the sliding members 52, 54 of the sliding members can slide, to provide a lubricated surface for that sliding and to avoid or reduce wear during the life of use of the smoke damper, as it is important that when the smoke damper needs to be opened by the automated smoke control system of the building, the trapdoor keep will function properly.

Referring next to figure 16 and 17, it can be seen how the tang 120 of the upper and lower catches 26 can engage with the keep 26 of its respective upper and lower latching unit 22, 24. As shown in figure 16, the tang 120 is retracted as the connecting rod 46 is extended by the transfer box assembly 48, in particular by having the slide assembly 74 pushed into the transfer box assembly 48. As discussed previously, pushing that slide assembly 74 into the transfer box assembly 48 moves the two actuator members 58, 68 apart from one another, which thus drives the connecting rods 46 apart from one another and thus towards the top and bottom ends of the door. With the chosen upper and lower latches 28, that outward movement of those connecting rods 46 can trigger the upper and lower latches 28 to move their tangs into their unlatching positions as shown in figure 16. That occurs when the motorised opening and closing mechanism drives its chain and out of its housing and thus attempts to push the door open. Thus the latches unlock at the top and bottom of the daughter allow the door to open (as will be disclosed below, this also opens the centre keep for fully allowing the door to open). However, if instead the door is being closed and locked, as the motorised opening and closing mechanism 16 pulls the door shut, it ultimately pulls the slide assembly 74 to its outwards position relative to the box 70 of the transfer box assembly 48, thus causing the coordinating slots to drive the actuator members 58, 68 back towards their closer together positions, which in turn draws back the connecting rods 46 to release the tang 120 back into its latching state as shown in figure 17.

In this embodiments, however, the or each of the upper and lower latches of the upper and lower latching units have a spring and trigger mechanism built in such that it or they can only be triggered to a latching state when the door is closed. This prevents out-of-turn movement of the connecting rods towards a latching state for the upper and lower latches prematurely moving the latches to their latching state, which might otherwise prevent the door from being closed properly by the motorised opening and closing mechanism. With this arrangement, even if the slide plate of the transfer box is pulled out, out of sequence or timing, the latches at the top and bottom cannot throw prematurely in a manner that could block the closing of the door. For this purpose, a spring and trigger mechanism 130 is built into the or each of the upper and lower latches, which triggers the or each of the upper and lower latches to close (to spring the tang 120) as the door is closed into the frame. This occurs as the trigger 130 bears against the racing surface of the keep 26. The trigger can be seen to be leaning out of the latching unit 28 in Figure 16, thus allowing the tang 120 to be retracted, but after it pushes against the keep, it springs into the latching unit as shown in Figure 17, releasing the tang 120 into its upper or lower keep 120. Such triggered latches 28 are available commercially.

It would of course be possible instead to have the trigger of the spring and trigger mechanism engaging with a part of the frame instead of the keep, as happens with some Yale locks.

With this arrangement it is possible for the following to occur: as the door reaches the point at which the upper and lower latches can throw and engage in a first part of the keep, the keep itself can press on the trigger 130 allowing the tang 120 to be released and throw into the keep. The engagement of the keeps by the upper and/or lower latches can be such that the latches themselves interact with the keeps, and due to their sprung design, pull the door fully closed, thus automatically improving or ensuring the engagement of the seal between the door and the frame near those latches, i.e. at the top and bottom of the door.

With these latching units, the door will thus lock both at the top and the bottom upon closing the door and will unlock at the top and the bottom upon opening the door due to the interaction of the motorised opening and closing mechanism 16, via the transfer box assembly 48, with the connecting rods for the upper and lower latching units 22, 24, which can reverse the trigger mechanisms to their primed status.

At the same time as operating the upper and lower latching units, the actuator members 58, 68 of the transfer box assembly 48 also slide the two sliding members 52, 54 and thus move the movable catch plates 50, 56. This is shown in figures 18 to 21. In figure 18 and 20, a cover 132 is still positioned over the sliding members 52, 54 and thus are less easily seen, although the opening of the keep - like a trapdoor - can be seen in these figures as the cover 132 is a suitable aperture for the tang of the centre latch.

Referring therefor to figure 19, when the slide assembly 74 is extended out of the box 70 of the transfer box assembly 48, the two sliding members 52, 54 are drawn together as the actuator members 58, 68, are at their closest together positions, as can be seen from the positions of the bolts 60 in figure 19. In this state, therefore, the two sliding members 52, 54 drawn together to close the trapdoor 136. As can be seen in figures 20 and 21, however, as the slide assembly 74 is driven back into the box 70 (in these figures it is only partially slid back in as is apparent from the inclined slots 76, 78 still being visible), by powering the motorised opening and closing mechanism 16 in an outward direction (for opening the door), it can be seen that this draws apart the two bolts 60 as the actuator members 58, 68 are drawn apart by their respective camming response within the inclined slots 76, 78 and the perpendicular slots 150. In return this starts to open the trapdoor because the sliding members 52, 54, and likewise the movable catch plates 50, 56, slide apart. Once fully open, it releases the tang of the centre latch thus opening the centre latching unit along with the upper and lower latching units, whereby the door can then be opened.

The present invention therefore provides a smoke damper having a multipoint latching mechanism which is operable by the motorised opening and closing mechanism, rather than requiring a handle to be operated.

The present invention also provides a multipoint latching mechanism for a smoke damper comprising all the above features of the multipoint latching mechanism, including the upper centre and lower latching units, the connecting rods and the motorised opening and closing mechanism, and mounting brackets, but without requiring the door or the frame. It is preferred nevertheless that the present invention provides the whole smoke damper system discussed above.

As the present invention can also be supplied in parts, the present invention also comprise a kit of parts containing all the above-described components of either the smoke damper or the multipoint latching mechanism for the smoke damper.

The present invention has been described above purely by way of example. Modifications in detail may be made to the invention within the scope of the claims as appended hereto.

Claims

CLAIMS:

1. A multi-point latching system for a smoke damper system comprising a motorised opening and closing mechanism for a smoke damper, and a multi-point latching mechanism which is mechanically connected to the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the smoke damper from a latched state, it unlatches the multi-point latching mechanism before then opening the smoke damper, and such that as the motorised opening and closing mechanism attempts to close the smoke damper, it closes the smoke damper before then latching the multi-point latching mechanism.

2. The system of claim 1, wherein the multi-point latching system has two rods that get pulled in to latch outer latches.

3. The system of claim 3, wherein the rods also operate a central latch.

4. A smoke damper system in the form of a door within a door frame, the door comprising a motorised opening and closing mechanism, and the door and frame between them comprising a multi-point latching mechanism which is mechanically connected to the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the door from a latched state, it unlatches the multi-point latching mechanism before then opening the door, and such that as the motorised opening and closing mechanism attempts to close the door, it closes the door before then latching the multi-point latching mechanism.

5. The system of claim 4, wherein the multi-point latching system has two rods that get pulled in to latch outer latches.

6. The system of claim 5, wherein the rods also operate a central latch.

7. The system of any one of claims 4 to 6, wherein latches of an upper and a lower latching unit are mounted onto the frame and keeps of the upper and the lower latching units are attached to the door, the keeps of the upper and lower latching units facing their corresponding latches of the upper and lower latching units when the door is closed such that they can achieve the latched state.

8. The system of any one of the preceding claims, wherein the multi-point latching mechanism comprises an upper latching unit and a lower latching unit, wherein the upper and lower latching units are provided with retractable latches and fixed keeps and the or each of the upper and lower latches of the upper and lower latching units have a spring and trigger mechanism built in such that it or they can only be triggered to a latching state when the door is closed.

9. The system of claim 8, wherein the spring and trigger mechanism built into the or each of the upper and lower latches triggers the or each of the upper and lower latches to close as the door is closed into the frame, the or each of the upper and lower latches engaging with the or each of the upper and lower keeps upon that triggering of the upper and lower latches.

10. The system of claim 8 or claim 9, wherein the engagement of a trigger of the spring and trigger mechanism with a part of the frame, or a part of the upper or lower keep, triggers the upper and/or lower latch to close.

11. The system of claim 8, claim 9 or claim 10, wherein, as the door reaches the point at which the upper and lower latches can throw and engage in a first part of the keep, the keep itself can press on the trigger allowing the upper or lower latch to be released and throw into the corresponding keep.

12. The system of any one of claims 8 to 11, wherein an engagement of at least one of the upper and lower keeps by at least one of the upper and lower latches can be such that the respective latch interacts with the respective keep, and due to the latch having a sprung design, that interaction pulls the door fully closed, thus providing an engagement of a seal that is located between the door and the frame near those latches.

13. The system of any one of the preceding claims, wherein three latching units of the multi-point latching mechanism are connected together on a frame by connecting rods extending either side of a transfer box assembly that is connected to the motorised opening and closing mechanism.

14. The system of claim 13, wherein a latch of the centre latching unit is on a door, and a keep of the centre latching unit is on a frame.

15. The system of claim 12, wherein the latch of the centre latching unit has a fixed tang.

16. The system of any one of the preceding claims, wherein a keep of a centre latching unit comprises at least one movable catch plate operable by the motorised opening and closing mechanism such that as the motorised opening and closing mechanism attempts to open the smoke damper from a latched state, it moves the at least one movable catch plate from a latch catching position to a non-catching position before then opening the smoke damper, and such that as the motorised opening and closing mechanism attempts to close the smoke damper, it closes the smoke damper before then moving the at least one movable catch plate from a non-catching position to a latch catching position.

17. The system of claim 16, wherein the at least one movable catch plate is a part of a sliding member that is operably attached to the transfer box assembly.

18. The system of claim 16 or claim 17, wherein a transfer box assembly connects between the catch plate and the motorised opening and closing mechanism.

19. The system of claim 18, wherein the transfer box assembly has one or more actuator member for moving therein in response to interaction of the motorised opening and closing mechanism with the transfer box assembly, the actuator assembly being operatively connected to the at least one movable catch plate, the motorised opening and closing mechanism thus when operating being able to move the at least one movable catch plate by operation of the transfer box assembly.

20. The system of any one of claims 16 to 19, wherein there are two moveable catch plates and both are movable by the motorised opening and closing mechanism.

21. A transfer box assembly comprising a box and a slide assembly, the box being mounted on a frame and the slide assembly being located part in the box and part out to a side of the box, such that it can slide more or less into or out of the box, the part extending out to a side of the box being connected to a motorised opening and closing mechanism for a door within the frame, the box and slide assembly each having at least one slot, the two slots being not parallel to one another, but being located so as to relatively intersect with one another through a movable but common perpendicular axis through a range of positions of the slide assembly relative to the box, the slots being for accommodating an actuator member such that as the slide assembly slides in and out of the box the accommodated actuator member slides along the slots to thus then move relative to the box and the slide member.

22. The transfer box assembly of claim 16, wherein there are two pairs of such slots and two actuator members.

23. The transfer box assembly of claim 21 or claim 22, wherein the slide assembly is mounted within the box with one or more spring being provided to bias the slide assembly into a less-extended-out-of-the-box state.

24. The system of any one of claims 1 to 20, further comprising the transfer box assembly of any one of claims 21 to 23.

25. The system of claim 24, wherein there are two actuator members and they are each connected to a separate connecting rod, such that the actuator member also operates upper and lower latching units that are connected to opposite ends of the connecting rods.

26. The system of claim 25, wherein the two connecting rods are pushed outwards relative to the transfer box assembly, each one towards its respective connected upper or lower latching unit, to unlatch the upper and lower latching units.

27. The system of any one of claims 24 to 26, wherein the actuator members move a pair of movable catch plates that act as a keep for a centre latching unit, such that they can separate from one another so as to open the keep like a trapdoor, and be pulled together again to close the keep.

28. The system of claim 27, wherein a timing of the closing of the keep is controlled such that they only close behind a tang of a centre latching unit on the door once the door is closed, the timing being achieved by providing springs inside a transfer box assembly of the multi-point latching mechanism that resist sliding out of a slide assembly from a box of the transfer box assembly until the door closes against the frame, the frame thus resisting further closing of the door and thus transferring any further movement of the motorised opening and closing mechanism towards closing the door into movement of the slide assembly outwards relative to the box.

29. The system of any one of claims 1 to 7 or 24 to 28, wherein the motorised opening and closing mechanism is a chain push/pull mechanism on a door of the smoke damper connected to a transfer box mechanism of the multi-point latching mechanism on a frame of the smoke damper.