AU2018101050A4 - Door frame fitting for a fire door having a lock with a square bolt - Google Patents

Abstract

Abstract A door frame fitting (10), for the jamb of a door frame that supports a door having a lock with a square bolt, has (i) a strike member (20) comprising a tongue member (12) having an inclined surface (21), (ii) a bolt activated member (50) having a first part (52) that has a planar surface (51), and (iii) a dead latch trigger mechanism. These components are in a housing comprising a front wall (30), a first side wall (31), a second side wall (32), a third side wall (33), a connecting wall (34) and a back wall (70). When the door is unlocked or open, the tongue member (12) and the planar surface (51) are positioned adjacent to each other at an aperture in the housing formed by two contiguous apertures (40, 41) in, respectively, the front wall (30) and the first side wall (31), being independently biased to be positioned thus by respective springs (29, 93). A block piece (23) of the strike member has a planar first surface (61) that is in sliding contact with the inner face of the connecting wall (34), and a second surface (62) from which a protuberance (58) extends. The bolt activated member (50) has a second part (53) with (i) a planar surface in sliding contact with a region of the second surface (62) of the block piece (23), and (ii) a shoulder member (54) positioned adjacent to the protuberance (58). A post (61) extends from the second part (53) into a slot (73) that is part of the dead latch trigger mechanism mounted on the back wall (70). When the open door is closed with the square bolt of its lock extended, the end of the square bolt contacts the inclined surface (21) to move the strike member (20) against its spring bias, away from the first side wall (31). Also, the protuberance (58) moves shoulder member (54), and thus the entire bolt activated member (50) by the same amount. The consequent movement of the post (61) within the slot (73) causes a deadlock lever (71) to activate the dead latch trigger. Means (80) to support a micro-switch operated by an arm (72) that extends from the deadlock lever (71) is included if the status of the door lock is monitored by an electrical circuit that includes a micro-switch. v36 70 i0

Description

COMPLETE SPECIFICATION (Innovation Patent)

Name of applicant/Nominated Person:

AMS Australia Pty Ltd

Address for Service:

AMS Australia Pty Ltd P.O. Box 146,

CIVIC SQUARE, A.C.T. 2608.

Invention title:

‘Door frame fitting for a fire door having a lock with a square bolt”

The following statement is a full description of this invention, including the best method of performing it known to us.

2018101050 25 Jul2018

Technical field.

This invention concerns locks. It was conceived to maintain security in a room fitted with a fire door in the (rare but not impossible) situation in which the door is opened and the room is evacuated because there is a fire in the building, but the square bolt of the lock of the opened door has been extended so that - in the case of normal door frame fittings the extended bolt would prevent the door closing properly. More particularly, this invention concerns a fitting for a door frame that enables io a door having a lock with a square bolt to be closed, after the door has been opened, notwithstanding that the square bolt of the lock of the door is at least partially extended.

The present invention has a particular application to fire doors used in is secure rooms, in which case the door frame fitting will be constructed to enable a micro-switch, that forms part of a lock status indicating circuit, to be mounted within the fitting. However, the invention is not limited to being used in a secure door application.

Preliminary note.

In this specification, including the claims, terms implying a direction or a relative position, such as “top”, “bottom”, “front”, “back”, “side”, “horizontally”, “vertically”, “rearwardly”, “upwardly”, and the like, will be used in the sense that these terms have when the unit or component being referred to is positioned as shown in Figure 1 of the accompanying drawings. Also, in this specification, including the claims, the term “square bolt” of a lock has the normal locksmith meaning, namely a bolt with at least the end thereof that extends from the lock being substantially planar and the plane thereof is orthogonal to the elongate

2018101050 25 Jul 2018 direction of the lock bolt. Typically, the cross-section of the square bolt is substantially rectangular, even if the generally rectangular cross-section is not a square cross-section and/or has rounded corners. In addition, in this specification, the term “bevelled surface” or “inclined surface” will mean a surface that is inclined relative to a particular reference plane; it includes an arcuate surface, the planar chord of which is inclined relative to a particular reference plane.

Background to the invention.

io The specification of Australian patent No. 2005270713 describes a micro-switch box in which a micro-switch and an “end-of-line” of a door lock monitoring arrangement for a high security room (a “Type 1 secure room”, also called a T1 secure room”) can be mounted. That microswitch box is constructed to be strong, and to be mounted within a door is frame, where access to the micro-switch box can occur only when the door that is being monitored Is open. That micro-switch box has been used, successfully, since shortly after its introduction to the security market.

Recent assessments of Australian Government T1 secure rooms that have a door that is required to be both a security door and a fire door has shown that there could be a problem when the micro-switch box technology is used with such a door, because doors to T1 secure rooms usually have a lock that has a square bolt. And, preferably, the door to such a room is equipped with two locks that can be unlocked simultaneously by the movement of a single handle (for example, using the arrangement described in the specification of Australian patent No.

2010202397). Indeed, that arrangement has become widely adopted because it is convenient for one of the locks to be a conventional latch

2018101050 25 Jul 2018 lock, for access to the room during normal daytime working hours, and for the other lock (possibly a night security lock) to have a square bolt, the position of which is monitored by circuitry connected to a microswitch in a micro-switch box of the type described in the specification of

Australian patent No. 2005270713.

Fire regulations do not permit fire doors to have locks with a square bolt. The concern that the fire door approval authorities have is that, in an emergency, when a fire door has been opened to allow persons inside a io room to leave that room, and when the last person has left the room, it is possible that the bolt of the lock of that door will have been extended again before the door is closed, or that the bolt (accidentally) will have been at least partially extended again and will not retain its full retraction into the lock. Therefore, when the last person to leave the room swings is the door to close it, the projecting end of the square bolt will contact the edge of the face plate on the door frame. The square bolt will not automatically retract. So the door will not be properly closed and air (with its combustion-assisting oxygen component) and flames can pass through the gap between the door frame and the edge of the “almost closed” door. In this situation, the fire resistance of the door is lost.

If the door is at the entrance to a secure room or location and is fitted with a micro-switch box and appropriate associated circuitry, the inability to fully close the door when the square bolt is extended also means that the security of the entrance has been compromised.

For the reason given above, such doors to secure rooms cannot be given an approved fire rating. Nevertheless, until recently, most certifying fire authorities have allowed a security door that is also constructed to be a

2018101050 25 Jul 2018 fire door, with a lock that has a square bolt, to be certified as a “nontagged fire door”. However, a number of fire authorities will no longer issue this form of certification, and it is expected that, very soon, the “non-tagged fire door” certification will no longer be available anywhere in

Australia.

Disclosure of the invention.

It is an objective of the present invention to provide a bolt-receiving fitting for a door frame that (a) permits an open door, having a lock with a io square bolt that has not been fully retracted, and thus has its end projecting from the lock, to be closed without full retraction of the square bolt, and (b) is configured so that, once the door closure is completed, (i) the projecting end of the square bolt performs its normal locking function, and (ii) mechanical linkages in the fitting ensure that, if a is micro-switch is included in the fitting, that micro-switch is activated to show that the door is locked.

This objective is achieved by a door frame fitting that has two components, which the present inventor has called a “strike member” (because, as will be apparent from the following description, it is struck by an extended square bolt of a lock of a door that is being closed, in a situation such as that noted above) and a “bolt activated member” (because, in the normal locking of the door having a lock with a square bolt, after the door has been closed, the square bolt, as it is extended, impacts this member and activates it to perform its required function), that are mounted, together with a dead latch trigger, within a housing that is attached to a jamb of a door frame.

The housing has a vertical planar front wall and a vertical planar first

2018101050 25 Jul 2018 side wall. These two walls meet each other along a common vertical edge region with the plane of the front wall orthogonal to the plane of the first side wall. An aperture in the housing is created by contiguous apertures, extending from the common edge region into the front wall and the first side wall. This aperture in the housing exposes (i) an inclined or bevelled face of a tongue member of the strike member that is adjacent to the front wall, and (ii) the planar surface of a first part of the bolt activated member, the plane of that planar surface being parallel to the plane of the first side wall, the planar surface being adjacent to the io inclined face of the tongue member and being substantially coplanar with the outer surface of the first side wall. Both the strike member and the bolt activated member are independently spring biased into this position.

When the housing is mounted on a jamb of a door frame, the first side is wall will be essentially coplanar with the planar inner face of the door frame and the front wall will be essentially coplanar with the front face of the jamb (that is, the face of the jamb that the lock of the door first approaches if the door attached to the door frame has been opened and is in the process of being closed).

The housing has other vertical walls, namely:

(a) a planar second side wall that extends rearwardly from a second side region of the front wall, the plane of the second side wall being parallel to the plane of the first side wall;

(b) a planar connecting wall extending from the rear edge region of the second side wall in a direction away from and orthogonal to the first side wall;

(c) a planar third side wall, extending rearwardly from the edge region of the connecting wall that is remote from the second

2018101050 25 Jul 2018 side wall; the third side wall having a vertical rear edge region; and (d) a planar back wall connecting the rear edge region of the first side wall and the rear edge region of the third side wall;

the plane of the back wall being parallel to the plane of the front wall (and, therefore, parallel to the plane of the connecting wail).

The tongue member of the strike member is mounted on two support io arms that are connected, by side arm members, to a block piece of the strike member. This block piece has a first surface that is planar and is adjacent to, and in sliding contact with, the inner face of the connecting wall of the housing. The spring bias of the strike member is preferably effected by a pair of heiical springs that extend between a respective is support arm and the second side wall of the housing. The block piece of the strike member has a second surface that is remote from its planar first surface. A major portion of this second surface is planar, with its plane parallel to the plane of its first planar surface. A protuberance extends from this second surface of the block piece of the strike member.

The bolt activated member has a second part that (i) has a planar surface that extends from the edge of the first part that is adjacent to the tongue member of the strike member, and (ii) is adjacent to and in sliding contact with the planar portion of the second surface of the block piece of the strike member. This second part of the bolt activated member has a shoulder member that, when the planar surface of its first part is essentially coplanar with the outer surface of the first side wall, is

2018101050 25 Jul 2018 positioned adjacent to the protuberance from the block piece of the strike member so that, when the strike member is moved, against its spring bias, away from the first side wall, the protuberance, acting on the shoulder member, moves the shoulder member, and hence the second part of the bolt activated member, away from the first side wall by the same amount and against the spring bias of the bolt activated member.

The spring bias of the bolt activated member is applied by at least one helical spring extending between the end of the second part of the bolt io activated member and a vertical, planar, third side wall of the housing that has its plane parallel to the plane of the first side wall (and, therefore, parallel to the plane of the second side wall).

The connecting wall of the housing connects a vertical edge region of the second side wall to the vertical edge region of the third side wall.

A dead latch trigger mechanism is mounted on the back wall. A short post that extends from the second part of the bolt activated member in a direction away from the strike member and towards the back wall (and parallel to the plane of the first, second and third side walls), is positioned within a slot of the dead latch trigger. When the bolt activated member is moved, against its spring bias, away from its position where the planar surface of its first part is essentially coplanar with the plane of the first side wall, that movement of this post in that slot enables the activation the mechanism of the dead latch trigger to hold the bolt activated member in its position away from the first side wall.

A pair of planar plates extend, respectively, above and below the strike member and the bolt activated member, between the first and third side

2018101050 25 Jul2018 walls. The planes of each of these two plates is orthogonal to the plane of each side wall, the connecting wall and the back wall. If the door frame fitting is to be used in the door frame of a room having an associated lock status indicating electrical circuit that includes a micro5 switch, and the micro-switch is to be mounted within the housing, a respective internally threaded hollow cylindrical post extends vertically away from at least one of these two plates. In this case, the planar plate, or each of the planar plates, is an internal plate and to complete the housing, a top wall and/or a bottom wall will be affixed, by io respective screws, to the internally threaded post or posts on the internal plate or plates. Means to mount a micro-switch will then be included in the space between the top and/or the bottom wall and its associated planar plate. (If a micro-switch will not be required in the housing, the two planar plates will become the top and bottom wails of the housing, is and the hollow cylindrical posts will not be present.)

To mount the door frame fitting in a door jamb, the first side wall has extensions above and below the top and bottom walls of the housing, and apertures (preferably countersunk) will be provided to enable the fitting to be attached to the jamb of the door frame, within which an appropriate space to receive the fitting has been established.

With a door frame fitting having the combination of features described above, if the associated door mounted on the door frame is open and is then moved to be closed, but has the square bolt of the door lock extended, when the extended square bolt of the closing door contacts the bevelled surface of the strike member, it forces the strike member against its spring bias and moves it, and with it the bolt activated member, until the end of the square bolt has passed over the tongue member of the

2018101050 25 Jul 2018 strike member to be positioned over the (retracted) planar surface of the first part of the bolt activated member. The tongue member of the strike member is then moved, by its spring bias, into the position it first occupied, thus preventing the square bolt of the door lock moving out of the door frame fitting and opening the door again. The square bolt is now in the position it normally occupies when the door has been closed and locked, the dead latch trigger has been activated and the bolt activated member has been locked in this position.

io Thus, according to the present invention, a door frame fitting for mounting on a first jamb of a door frame on which a door is mounted on the second jamb of said door frame; said door (i) having a lock that includes a square bolt, and (ii) being mounted on said door frame to move between a fully open position and a fully closed position, and, when fully closed and subsequently locked normally, said square bolt projects into said door frame fitting; said door frame fitting comprising a strike member and a bolt activated member mounted adjacent to each other within a housing; said first jamb having an inner face and a front face; said housing comprising:

(e) a planar vertical front wall that, when said door frame fitting is mounted on said first jamb of said door frame, is parallel to and substantially aligned with said front face of said first jamb;

(f) a planar vertical first side wall that extends rearwardly from a first side region of said front wall and, when said door frame fitting is installed on said first jamb, is substantially aligned with said inner face of said door jamb at the location of installation; said first side wall having a vertical rear edge region;

2018101050 25Jul 2018 (g) a planar vertical second side wall that extends rearwardly from a second side region of said front wall, the plane of said second side wail being parallel to the plane of said first side wall;

(h) a planar vertical connecting wall extending from the rear edge region of said second side wall in a direction away from and orthogonal to said first side wall;

(i) a planar vertical third side wall, extending rearwardly from the edge region of said connecting wall that is remote from said second side wall; said third side wall having a vertical rear edge region; and (j) a planar back wall connecting said rear edge region of said first side wall and said rear edge region of said third side wall; the plane of said back wall being parallel to the plane of said front wall;

characterised in that:

• said front wall has an aperture therein extending from the vertical edge region thereof that is adjacent to said first side wall, and said first side wall has an aperture therein extending from the vertical edge region thereof that is adjacent to said front wall; said apertures being contiguous and forming a single aperture in said housing;

• said strike member has a tongue member that has an inclined surface extending across said contiguous apertures with a linear edge of said inclined surface being parallel to the plane of, and substantially coplanar with, said first side wail;

• said bolt activated member has a first planar part that has an outer surface that (i) is positioned within said aperture in said first side wall, and (ii) extends rearward from said linear edge

2018101050 25 Jul 2018 of said strike member; the plane of said outer surface being parallel to, and substantially aligned with, said first side wall;

• said strike member and said bolt activated member are independently spring biased into the position in which said linear edge and said outer surface are substantially co-planar with said first side wall;

• said bolt activated member has a second part with a planar surface, the plane of which is parallel to said front wall, said second part extending from said first planar part alongside said io strike member, said second part having a shoulder member; a protuberance from said strike member being positioned adjacent to an edge of said shoulder member that faces said first side wall; whereby, when said strike member is moved against its spring bias in a direction parallel to said front wall and away is from said first side wall, said protuberance causes said shoulder member, and hence said bolt activated member, to move in the same direction and against its independent spring bias, by the same amount;

• said second part has a post extending therefrom in a direction orthogonal to the plane of said planar surface of said second part; said post being operatively positioned within a slot of a dead latch trigger mounted on said back wall so that, when said bolt activated member is moved to a position in which said first part is remote from said first side wall, said post moves within said slot to allow a deadlocking lever to be rotated about a pivot pin into a position in which said dead latch trigger is operative to deadlock said bolt activated member in its position remote from said first side wall;

whereby said square bolt, if extended when said door is open, can

2018101050 25 Jul2018 pass through said aperture in said front wall to impact on said inclined surface of said tongue member and cause said tongue member, and hence said entire strike member, to move against its spring bias, and hence cause said bolt activated member to move by the same amount against its spring bias, and permit said extended square bolt to pass over said inclined surface, and over said outer surface of said bolt activated member, until (i) said square bolt is clear of said linear edge of said tongue member and said strike member is returned, by the action of its associated io spring bias, to the position in which said linear edge is again substantially coplanar with said first side wall and said tongue member prevents movement of said extended bolt out of said single aperture; and (ii) said bolt activated member has been moved to the position in which it has activated said dead latch is trigger.

An embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

Brief description of the drawings.

Figure 1 is a partly schematic perspective sketch of a realisation of the door frame fitting of the present invention.

Figure 2 is another partly schematic, perspective sketch of the realisation of the door frame fitting of the present invention shown in Figure 1.

Figures 3 and 4 each illustrate the preferred configurations of the strike member and the bolt activated member of the door frame fitting illustrated

2018101050 25 Jul 2018 in Figures 1 and 2.

Figure 5 shows, partly schematically, (i) in Figure 5(a), how the components of the door frame fitting featured particularly in Figures 1, 2, 3 and 4 are assembled on the front, side and connecting walls of the housing when the associated door is open and/or unlocked;

(ii) In Figure 5(b), how additional components are assembled on the back wall of the door frame fitting when the associated door io is open and/or unlocked; and, in Figure 5(c), (iii) how additional components assembled on the back wall of the door frame fitting have moved when the bolt activated member has been moved away from the first side wall of the housing.

is Figure 6 is a partly schematic top view (in the direction of the arrow B of

Figure 1) of the door frame fitting illustrated in Figure 1.

Detailed description of the illustrated embodiment.

The door frame fitting 10 shown in the perspective sketches of Figures 1 and 2 comprises a chamber within which a strike member 20 (having a tongue member 12 with an exposed inclined or bevelled surface 21) and a bolt activated member 50 (having an exposed surface 51) are mounted. This chamber comprises a front wall 30, a first side wall 31, a second side wall 32, a third side wail 33, a connecting wall 34 (called a connecting wall because it connects the second side wall 32 to the third side wall 33), and a back wall /0. The walls 30, 31 and 32 have been formed by folding a plate of steel; the walls 33 and 34 have been formed by folding another sheet of steel. The two folded sheets have been welded together along the line 324 (see Figures 2 and 6) where

2018101050 25 Jul 2018 the walls 32 and 34 abut against each other. This is regarded as the most convenient and effective way of constructing the housing but other suitable materials and construction techniques may be used to form the wails 30, 31, 32, 33 and 34.

Because the housing wails, in the illustrated embodiment, have been formed by folding steel sheets, there are a number of curved surfaces where one wail connects with an adjacent wall. For this reason, the term “edge region” will has been used already and will continue to be used in io this description instead of “edge” when referring to the walls of the housing.

To complete the housing of the door frame fitting shown in Figures 1 and

2, if a micro-switch is likely to be included in the housing, a top end wall is (not shown) and a bottom end wall (also not shown) will be attached, respectively, by screws, to internally threaded hollow cylindrical posts 36 and 37 that extend from, respectively, the upper and lower planar plates and 39. If a micro-switch will not be included in the housing, the plates 38 and 39 will become the top and bottom walls of the housing and the posts 36 and 37 will not be required.

As also shown in Figures 1 and 2, the front wall 30 and the first side wall 31 have contiguous cut-out portions 40 and 41, respectively, that expose (a) the bevelled surface 21 of the tongue member 12 of the strike member 20, and (b) a planar surface 51 of the bolt activated member 50 that is essentially co-planar with the plane of the first side wall 31.

The first side wall 31 extends above and below the top and bottom walls

2018101050 25 Jul 2018 of the housing. These extended parts of the first side wal! have apertures 42 in them to enable the fitting to be mounted, using screws, on a jamb of a door frame. Optional internally threaded hollow cylindrical posts 44 are provided to enable a cover plate to be fitted over the front wall 30. This cover plate will have a cut-out portion corresponding to the cut-out portion 40 if it covers essentially all of the front wall 30.

Figures 3 and 4 show the preferred construction of the strike member 20 and the bolt activated member 50.

io

The strike member 20 comprises a block piece 23 having a planar first surface 61 and a second surface 62. A pair of elongate side arm members 22 extend from the sides of the block piece 23. A pair of support arms 25 extend, respectively, from the ends of the side arm members and at right angles to the elongate direction of the side arm members, to support, respectively, the ends of the elongate tongue member 12 (a) that has an essentially triangular cross-section, and (b) one surface of which is the sloping or bevelled surface 21.

Preferably the strike member 20 is machined from a single block of brass (although other suitable materials and other ways of fabricating the strike member 20 may be used).

Ignoring, for the moment, the protuberance 58 and the lug 59 that extend from, and the indentation 37 into, the surface 62 of the block piece 23, the distance between the surfaces 61 and 62 of the block piece is less than the distance between surfaces 28 and 24 of the side arms 22 by an amount essentially equal to the thickness of a planar second part 53 (described in more detail below) of the bolt activated

2018101050 25 Jul2018 member 50,

In the door frame fitting 10 shown in the drawings, the first surface 61 of the block piece 23 and the surfaces 28 of the side arm members 22 are (a) as shown in Figure 3, co-planar, and (b) positioned alongside, and in sliding contact with, the inner surface of the connecting wail 34. A pair of helical springs 29, one end of each spring being in contact with the second side wall 32 and the other end of each spring being positioned within a respective drilled-out cavity 27 of circular cross-section in the io support arms 25, bias the strike member 20 into the position it has in

Figures 1 and 2, which is also the position it occupies in Figure 5(a).

The illustrated bolt activated member 50 comprises a single plate of metal (preferably steel) that is bent to form the planar first part 52, the is outer surface of which is the surface 51, and a planar second part 53.

The planes of the parts 52 and 53 are orthogonal. The planar second part 53 of the bolt activated member 50 has a cut-out portion 56 so the planar part 53 can be positioned adjacent to, and with its surface shown in Figure 3 in sliding contact with, a planar region of the second surface

62 of the block piece of the strike member 20. In this position, the surface of the planar second part 53 which is visible in Figure 4 is substantially co-planar with the surfaces 24 of the side arm members 22 of the strike member 20.

A shoulder member 54 extends into the cut-out portion 56, underneath (in the view shown in Figure 4) the protuberance 58 and the locating lug 59 extending from the second surface 62 of the block piece 23.

Two cuts into the lowest (in Figure 4) surface of the second planar part define a short rib 55, on which one end of a third helical spring 93

2018101050 25 Jul 2018 (see Figure 5) is located when the door frame fitting is assembled. This third helical spring 93 (for the presence of which the generally hemispherical indentation 57 is provided in the block piece 23) biases the bolt activation member 50 into the position it has in Figure 1 - and also in Figure 5(a) - with its surface 51 parallel to the top linear edge 2 6 of the tongue member 12 of the strike member 20.

A cylindrical post 60, located close to the cuts that define the rib 55, extends from the surface of the planar part 53 that is visible in Figure 4. io The indentation between the indentation 57 and the protuberance 58 in the block piece 23 is provided to receive any part of the post 60 that extends behind (in the Figure 4 representation) the planar second part and ensure the sliding contact of the planar second part 53 and the second surface 62 of the block piece 23.

With the strike member 20 mounted, as described above, with the bevelled surface 21 as shown in Figures 1, 2 and 5(a), the bolt activated member 50 is mounted, as shown in Figure 5(a), (i) with the face of its second planar part 53 that is visible in Figure 3 adjacent to, and in sliding contact with, the surface 62 of the block piece 23, and (ii) with its shoulder 54 directly underneath - using the orientation of components in Figure 4 - the protuberance 58 that extends from the surface 62 of the strike member 20.

Figure 5(a) shows the assemblage of the strike member 20 and bolt activated member 50 within the chamber partially defined by walls 30,

31, 32, 33 and 34, as described above. Additional features shown in

Figure 5(a) include the plate 63 that overlies that part of the inner face of the third side wall 34 that is in the region between plates 38 and 39.

2018101050 25 Jul 2018

The plate 63 has a circular aperture in it to receive and locate one end of the third helical spring 93. It has no additional purpose.

Also shown in Figure 5(a), and in Figures 1 (partially), 2 and 6, are a pair of relatively thin threaded posts 80, extending upwardly from the plate 38. These posts 80 are provided so that a lever type micro-switch can be mounted on the posts 80 in the space bordered by the connecting wall 34, the third side wall 33, the plate 38, the top end wall of the chamber (not shown) and the back wall 70. If a micro-switch is to io be mounted on the posts 80, a slot 82 (see Figures 2 and 6) will be present in the plate 38 to enable an arm 72, that extends from a rotatable deadlocking lever 71, to enter the space in which a microswitch will be mounted. The arm 72 is positioned so that it switches an installed lever type micro-switch on” or “off” (depending on the circuitry is in which the micro-switch is connected) when the deadlocking lever 71 is activated as a result of movement of the bolt activated member 50 away from the first side wail 31. Such movement will be caused either by the bolt of the door lock as normal locking of the security door is effected, or by the bolt activated member being moved by the protuberance 58 acting on the shoulder 54 as the tongue member 12 of the strike member 20 (and hence the entire strike member) is moved away from the first side wall 31 when the tongue member is impacted by the square bolt of the door, following opening of the door then attempting to close it again with the square bolt of the door lock extended.

Of course, as indicated above, the fire door mounted on the door frame into which the door frame fitting has been installed need not be a security door, in which case the posts 80 and the slot 82 will be absent from the door frame fitting.

2018101050 25 Jul 2018

As shown in Figure 5(b) and 5(c), a known form of dead latching trigger is mounted on the plate which is the back wall 70 of the housing. In the illustrated embodiment, three smaller rectangular plates, having the same dimensions, are positioned on the inner surface of the back wall 70 with the aid of three locating pins 78. The smaller plate in contact with the back wall 70 is simply a spacer plate. The middle plate 90 of the three smaller plates has (i) a slot 73 cut into It and (ii) a pivot pin 74 and a deadlocking pin 84 extending from it. In the assembled door frame fitting, the post 60 extends from the second part 53 of the bolt activated io member into the slot 73. The third smaller plate 91 has a cut out region within which are located the pivot pin 74, a deadlocking pin 84 (that also extends from the middle smaller plate 90) and the deadlocking lever 71.

is The lever 71 has a first edge length 85 that, when the door mounted on the door frame is open and/or unlocked, is, as shown in Figure 5(b), adjacent to the edge length 86 of the cut-out region of the third smaller plate 91, as also shown in Figure 5(b). The lever 71 has a second edge length 89 that is remote from the first edge length 85, and is parallel to the edge length 85. One end of the edge length 89 connects with an inclined edge length 89A. The lever 71 also has (i) an aperture in it, into which the pivot pin 74 extends, (ii) an arm 72 (discussed above), and (iii) a removed central region 88. The removed region 88 is shaped so that a shoulder 87 is provided at the junction of a slot that extends parallel to the edge 85 and a more open part of the region 88.

The deadlocking pin 84 is located close to the shoulder 87 and, when the lever 71 is rotated about the pivot pin 74, is positioned adjacent to the shoulder 87, as shown in Figure 5(c).

2018101050 25 Jul 2018

The cut-out portion of the third smaller plate 91 has two slots extending from it to provide a short rib 75 that, in the same manner as the rib 55 of the planar second part 53, supports one end of a fourth helical spring (not shown). The other end of the fourth helical spring is supported on a similar rib 76 formed in the outer edge of the lever 71. This fourth helical spring is in compression when the lever 71 is in the position shown in Figure 5(b). The lever 71 is held in this position by the post 60, within the slot 73, bearing against the second edge length 89 of the lever 71.

io When the associated door is open and/or unlocked, the components are all located as shown in Figure 5(a) and 5(b). As the bolt activated member 50 is moved away from the first side wall 31 (either by locking the door when it has been closed or by the action of the protuberance 58 on the shoulder 54 as a consequence of the tongue member 12 of is the strike member 20 being forced away from the first side wall 31), the post 60 is moved in the slot 73 and one end of the inclined edge length 89B comes into contact with the post 60. The post 60 then moves along the edge length 89B and as it does so, the action of the fourth helical spring causes the lever 71 to rotate about the pivot pin 74 and for the deadlocking pin 84 to become positioned adjacent to the corner created by the shoulder 87. This situation is shown in Figure 5(c). In this position the lever 71 is deadlocked.

During this rotary movement of the lever 71, the arm 72 has moved to the position shown in Figure 5(c), and thus has changed its action on the lever of a micro-switch mounted on the posts 80, so that the microswitch has changed from “on” to “off”, or vice versa.

If the components mounted on the back wall 70 have reached the

2018101050 25 Jul 2018 positions shown in Figure 5(c) because the associated door mounted on the door frame has been opened and has then been closed with the square bolt of the door lock extended, once the extended square bolt has cleared the strike member (after forcing it out of the path of the extended square bolt) and is positioned over the (retracted) planar surface of the first part of the bolt activated member, the helical springs 29 move the tongue member back into the position it first occupied, thus preventing the square bolt of the door lock moving out of the door frame fitting and allowing the door to be opened again.

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Locksmiths and security experts will appreciate that the door frame fitting of the present invention that has been illustrated in the accompanying drawings and described above is one example only of a realisation of the present invention, and that variations in or modifications to this door frame fitting may be made without departing from the present inventive concept, as set out in the following claims.

2018101050 25 Jul2018

Claims (5)

1. The claims defining the invention are as follows:

   1. A door frame fitting for mounting on a first jamb of a door frame on which a door is mounted on the second jamb of said door frame; said door (i) having a lock that includes a square bolt, and (ii) being mounted on said door frame to move between a fully open position and a fully closed position, and, when fully closed and subsequently locked normally, said square bolt projects into said door frame fitting; said door frame fitting comprising a strike member and a bolt activated member mounted adjacent to each other within a housing; said first jamb having an inner face and a front face; said housing comprising:

   (a) a planar vertical front wall that, when said door frame fitting is mounted on said first jamb of said door frame, is parallel to and substantially aligned with said front face of said first jamb;

   (b) a planar vertical first side wall that extends rearwardly from a first side region of said front wail and, when said door frame fitting is installed on said first jamb, is substantially aligned with said inner face of said door jamb at the location of installation; said first side wall having a vertical rear edge region;

   (c) a planar vertical second side wall that extends rearwardly from a second side region of said front wall, the plane of said second side wall being parallel to the plane of said first side wail;

   (d) a planar vertical connecting wall extending from the rear edge region of said second side wail in a direction away from and orthogonal to said first side wall;

   2018101050 25 Jul 2018 (e) a planar vertical third side wall, extending rearwardly from the edge region of said connecting wall that is remote from said second side wall; said third side wall having a vertical rear edge region; and (f) a planar back wall connecting said rear edge region of said first side wall and said rear edge region of said third side wall; the plane of said back wall being parallel to the plane of said front wail;

   characterised in that:

   • said front wail has an aperture therein extending from the vertical edge region thereof that is adjacent to said first side wall, and said first side wall has an aperture therein extending from the vertical edge region thereof that is adjacent to said front wall; said apertures being contiguous and forming a single aperture in said housing;

   • said strike member has a tongue member that has an inclined surface extending across said contiguous apertures with a linear edge of said inclined surface being parallel to the plane of, and substantially coplanar with, said first side wait;

   • said bolt activated member has a first planar part that has an outer surface that (i) is positioned within said aperture in said first side wall, and (ii) extends rearward from said linear edge of said strike member; the plane of said outer surface being parallel to, and substantially aligned with, said first side wall;

   • said strike member and said bolt activated member are independently spring biased into the position in which said linear

   2018101050 25 Jul 2018 edge and said outer surface are substantially co-planar with said first side wall;

   • said bolt activated member has a second part with a planar surface, the plane of which is parallel to said front wall, said second part extending from said first planar part alongside said strike member, said second part having a shoulder member; a protuberance from said strike member being positioned adjacent to an edge of said shoulder member that faces said first side wall; whereby, when said strike member is moved against its spring bias in a direction parallel to said front wall and away from said first side wall, said protuberance causes said shoulder member, and hence said bolt activated member, to move in the same direction and against its independent spring bias, by the same amount;

   • said second part has a post extending therefrom in a direction orthogonal to the plane of said planar surface of said second part; said post being operatively positioned within a slot of a dead latch trigger mounted on said back wall so that, when said bolt activated member is moved to a position in which said first part is remote from said first side wall, said post moves within said slot to allow a deadlocking lever to be rotated about a pivot pin into a position in which said dead latch trigger is operative to deadlock said bolt activated member in its position remote from said first side wall;

   whereby said square bolt, if extended when said door is open, can pass through said aperture in said front wall to impact on said inclined surface of said tongue member and cause said tongue member, and

   2018101050 25 Jul2018 hence said entire strike member, to move against its spring bias, and hence cause said bolt activated member to move by the same amount against its spring bias, and permit said extended square bolt to pass over said inclined surface, and over said outer surface of said bolt activated member, until (i) said square bolt is clear of said linear edge of said tongue member and said strike member is returned, by the action of its associated spring bias, to the position in which said linear edge is again substantially coplanar with said first side wall and said tongue member prevents movement of said extended bolt out of said single aperture; and (ii) said bolt activated member has been moved to the position in which it has activated said dead latch trigger.
2. 2. A door frame fitting as defined in claim 1, in which (a) said tongue member is supported by a pair of support arms that are connected by respective side arm members to a block piece;

   (b) said block piece has a planar first surface that is in sliding contact with said connecting wall; and (c) said block piece has a second surface with a planar region, the plane of which is parallel to the plane of said first surface of said block piece, and from which said protuberance extends.
3. 3. A door frame fitting as defined in claim 2, in which said spring bias of said strike member comprises a pair of helical springs, each positioned between a respective one of said support arms and said second side wall.

   2018101050 25 Jul 2018
4. 4. A door frame fitting as defined in claim 1, claim 2 or claim 3, in which said bolt activated member comprises two plate-like members; one of said plate-like members forming said first part of said bolt activated member and the other of said plate-like member forming said second part of said bolt activated member.
5. 5. A door frame fitting as defined in any preceding claim, in which said strike member and said bolt activated member are mounted between a first internal plate and a second internal plate; each of said internal plates being a planar plate, the plane of which is perpendicular to the planes of (i) said front wall, (ii) said first, second and third side walls, (iii) said connecting wall, and (iv) said back wall; further characterised in that (a) each of said internal plates has an internally threaded hollow cylindrical post extending from the face thereof that is remote from said strike member and said bolt activated member, whereby a top wail and a bottom wall of said housing may each be mounted on a respective one of said hollow cylindrical posts; and (b) micro-switch mounting means is provided on one of said internal plates, whereby a micro-switch may be positioned between that internal plate and its associated top or bottom wall.