AU2019200209A1

AU2019200209A1 - Lock box

Info

Publication number: AU2019200209A1
Application number: AU2019200209A
Authority: AU
Inventors: Tim Everett; Jon Seddon
Original assignee: KDB Intellectual Pty Ltd
Current assignee: KDB Intellectual Pty Ltd
Priority date: 2018-01-11
Filing date: 2019-01-11
Publication date: 2019-07-25
Anticipated expiration: 2039-01-11
Also published as: AU2019200209B2

Abstract

A self-latching lock box comprising a displaceable securing tongue adapted to be momentarily displaced upon receiving a latch arm for latching thereto, wherein the latch arm is releasable from the lock box without displacing the securing tongue. Figure 2A

Description

Lock Box

FIELD OF THE INVENTION [0001] The present invention relates to latching devices for use on doors such as security doors, emergency fire exit doors, and the like. More specifically, the present invention relates to a lock box adapted to receive a latch arm for latching, and suitable for installation on a doorway where security is desired.

BACKGROUND TO THE INVENTION [0002] Latching devices installed on emergency fire exist doors are provided to keep building occupants inside, as opposed to preventing an unauthorised person from entering the building. Australian regulations dictate that emergency fire exit doors must be self-closing or automatic, and locked upon closing, to prevent the door leaf from being opened without manual release of a latch arm. Also, non-self latching bolts, such as dead bolts, which render a door leaf non-self latching cannot be used because the bolt would prevent the door leaf from closing if the bolt is left protruding.

[0003] A typical latching device for an emergency fire exit door incorporates a latch arm or bolt, which is fixed to a door leaf at its outermost edge and upon closing the door, the bolt is arranged to be positioned adjacent to an aperture located in a door frame of the exit. The bolt is slidingly moveable between an extended (i.e., locked) position and a retracted (i.e., unlocked) position, wherein the locked position comprises a peripheral end of the bolt being positioned away from the edge of the door leaf such that when the door leaf engages the door frame, the peripheral end of the bolt is moveable to rest within the door frame aperture to prevent reopening of the door.

[0004] A problem exists with this type of latching device in that the latch arm must be in the retracted position in order to allow the door leaf to completely engage the door frame and come to a completely closed position. When the latch arm is in the extended position (or partially extended), the latch arm strikes the side face of the door frame, and is positioned off-set from the door frame aperture thereby

-22019200209 11 Jan 2019 preventing the door leaf from completely closing, and preventing the peripheral end of the bolt to be slidingly moved to the locked position and into the door frame aperture. Consequently, the latch arm is not aligned properly with the aperture in the door frame, and although the door appears closed, it is not latched.

[0005] The present invention aims to at least ameliorate the above problem by providing a self-latching lock box, which is adapted to receive a latch arm in either of its extended position or in its retracted position, to allow complete closure of the door leaf for latching. The present invention also aims to provide at least another alternative latching device for security doors.

SUMMARY OF THE INVENTION [0006] The applicant has developed a self-latching lock box adapted to receive a latch arm of a security device for latching, which in use on a doorway, enables the door leaf to be completely closed regardless of the latch arm being in its extended position or retracted position.

[0007] In a first aspect, the present invention provides a self-latching lock box comprising a displaceable securing tongue adapted to be momentarily displaced upon receiving a latch arm for latching thereto, wherein the latch arm is releasable from the lock box without displacing the securing tongue.

[0008] In a second aspect, the present invention provides a self-latching lock box comprising a rotatable hooking means for preventing relative movement of a displaceable securing tongue adapted to be momentarily displaced upon receiving a latch arm, wherein the rotatable hooking means engages the securing tongue upon receipt of the latch arm.

[0009] In a third aspect, the present invention provides a kit of parts comprising (i) a latch arm; and (ii) a self-latching lock box according to the first aspect or the second aspect, wherein the kit of parts in use provides a self-latching device for latching in a pre-determined latched position which are otherwise moveable relative to one another along a latching pathway when affixed to a door leaf and door frame, respectively, the parts being arranged such that when the latch arm is received by the lock box comprising a displaceable securing tongue in the pre-determined

-32019200209 11 Jan 2019 latched position, relative movement of the displaceable securing tongue is prevented.

[0010] In a fourth aspect, the present invention provides a kit of parts comprising (i) a latch arm; and (ii) a self-latching lock box according to the first aspect or the second aspect, wherein the kit of parts in use provides a self-latching device for latching in a pre-determined latched position which are otherwise moveable relative to one another along a latching pathway when affixed to a door frame and door leaf, respectively, the parts being arranged such that when the latch arm is received by the lock box comprising a displaceable securing tongue in the pre-determined latched position, relative movement of the displaceable securing tongue is prevented.

[0011] In one embodiment of any of the above aspects, the securing tongue is biased towards a closed position. Preferably, the securing tongue is biased with a helical compression spring, serpentine spring, or any other suitable biasing structure that momentarily stores and releases energy.

[0012] In another embodiment of any of the above aspects, the securing tongue comprises a strike face. The strike face is preferably chamfered (i.e., wedge-shaped) to provide a gradient surface to assist in gradually displacing the securing tongue upon contact with a latch arm and movement thereof towards an open position.

[0013] In another embodiment of any of the above aspects, the securing tongue comprises an abutment. In this embodiment, the abutment may be a slot or protrusion and may be any size and shape in, or on, the structure of the securing tongue for securing a hook.

[0014] In another embodiment of any of the above aspects, the lock box further comprises a rotatable hooking means adapted to (i) hook into the slot of the securing tongue, or (ii) frictionally abut against a protrusion on the securing tongue, to prevent relative movement of the securing tongue, upon receiving the latch arm.

[0015] In another embodiment of any of the above aspects, the rotatable hooking means comprises a latch arm-receiving shoulder lever and a hooking lever comprising a hook.

-42019200209 11 Jan 2019 [0016] In another embodiment of any of the above aspects, the latch arm-receiving shoulder lever is biased towards the securing tongue and the hooking lever is biased away from the abutment. In this embodiment, the latch arm-receiving shoulder lever is biased towards the strike face of the securing tongue with a first spring, and the hooking lever is biased away from the abutment of the securing tongue with a second spring.

[0017] In another embodiment of any of the above aspects, the latch arm-receiving shoulder lever comprises at least one chamfered shoulder. In this embodiment, the chamfered shoulder provides a second gradient surface to assist in gradually inserting a latch arm from a direction substantially perpendicular to the plane of the latching pathway. As the latch arm is inserted and positioned in the latching position, the latch arm-receiving shoulder lever rotates which in turn rotates the hooking means. The hook then engages the abutment of the securing tongue to prevent relative movement.

[0018] Preferably, the latch arm-receiving shoulder lever comprises two chamfered shoulders. Two chamfered shoulders located on the latch arm-receiving shoulder allow the lock box to be bi-directionally orientatable for use in either left-hand opening doors or right-hand opening doors.

[0019] In some embodiments, the components of the lock box are made from metal or alloy, preferably from a fire-resistant metal or alloy. In certain embodiments, at least one of the lock box components is made from grade 316 stainless steel. In other embodiments, at least one of the components is made from plated steel. It would be understood that grade 316 stainless steel comprises chromium, nickel and molybdenum, where the molybdenum assists in providing corrosion resistance.

[0020] In one embodiment, the securing tongue is displaceable in a length-wise direction along the length of the lock box housing. In one embodiment, the lock box housing incorporates a sleeve through which the securing tongue is slidable between an open position and a closed position. In some embodiments, the sleeve may be formed by the internal walls of the housing together with a backing plate or block, such as a securing block to encase the securing tongue. In another embodiment, the

-5 2019200209 11 Jan 2019 lock box housing incorporates rails therein along which the securing tongue is slidably guided between an open position and a closed position.

[0021] A user is provided with an option to orientate and install the lock box on a door leaf or door frame. In one embodiment, when the lock box is installed horizontally on a door frame (or door leaf) and the latch arm is installed vertically on a door leaf (or door frame), the displaceable securing tongue is orientated to be displaceable horizontally. Alternatively, in another embodiment, when the lock box is installed vertically on a door frame (or door leaf) and the latch arm is installed horizontally on a door leaf (or door frame), the displaceable securing tongue is orientated to be displaceable vertically. It would be understood that vertical upward displacement is potentially advantageous in that the displaceable securing tongue is maintained under gravity to be biased towards the downward closed position when in that orientation. Therefore, when the lock box is affixed in the vertical orientation, a spring (such as a helical compression spring) or other biasing means, to bias the securing tongue towards the closed position is not required.

[0022] The vertical displacement embodiments of the invention are suitable for installation on doors, door frames, fire doors, fire door frames, and the like where reducing the number of components is desired, reducing manufacturing complexity and/or reducing manufacturing costs.

[0023] In another aspect, the present invention provides a method of operating a latch arm with a lock box as described above in the first or second aspect, the method comprising: (i) releasing the latch arm by moving the latch arm towards the retracted position and away from the latching position, the releasing being effected by retracting the latch arm in a direction substantially perpendicular to the plane of the latching pathway, and/or (ii) securing the latch arm by moving the latch arm towards the extended position and into the latching position, the securing being effected by extending the latch arm in a direction substantially perpendicular to the plane of the latching pathway.

[0024] To release the latch arm from the self-latching lock box of the present invention, it would typically be necessary to manually pull the latch arm to the retracted position in a direction substantially perpendicular to the latching pathway.

-62019200209 11 Jan 2019 [0025] Further embodiments of the invention can readily incorporate a lock with a removable key.

[0026] Further embodiments of the invention can readily incorporate a signalling means to communicate the locked or unlocked status of the lock box.

[0027] In one embodiment, the locked/unlocked status of the lock box may be visually communicated with indicia, for example, by displaying a certain word, phrase and/or colour to signify the locked/unlocked status. In certain embodiments, the indicia may be located in the lock box housing and visible through an aperture or window located on the housing. In one embodiment, the word “locked” may be used to indicate the locked status, and the word “unlocked” may be used to indicate the unlocked status. In another embodiment, the colour red may be used to indicate the locked status, and a different colour, such as the colour green, may be used to indicate the unlocked status.

[0028] In another embodiment, the locked/unlocked status of the lock box may be electronically communicated, for example, by utilising an electronic signalling means, such as a micro switch or a printed circuit board (PCB), to electronically signal the locked or unlocked status of the lock box. The signalling means may be located in or on the lock box housing and suitably positioned therein or thereon such that the signalling means toggles between two states, corresponding to its on and off states, in response to movement of a hooking means, such as a hook pawl or hooking lever comprising a leg extending therefrom, between the locked position and the unlocked position. In certain embodiments, the micro switch may comprise a lever which may be pushed to its “on” or “locked” position via interaction with the leg extending from the hooking means in response to the lock box receiving a latch arm, or pushed to its “off’ or “unlocked” position via interaction with the leg extending from the hooking means in response to the latch arm vacating the lock box.

[0029] The present invention will now be exemplified with reference to a doorway requiring secure automatic latching on closure and simplified manual unlatching, but it is to be understood that the invention extends to embodiments intended for

2019200209 11 Jan 2019

-7other applications including double doors, sliding doors and other structures where latching is desired.

BRIEF DESCRIPTION OF THE FIGURES [0030] In order that the present invention may be readily understood and put into practical effect, reference will now be made to the accompanying illustrations, wherein like reference numerals refer to like features and wherein:

[0031] Figure 1A is an illustration of a lock box of the present invention affixed to the underside surface of a door frame, and a latch arm device affixed to a comer edge of the door.

[0032] Figure IB is a cross-sectional view of the lock box and latch arm of Figure 1A.

[0033] Figure 2A is an illustration of a lock box of the present invention affixed to the side surface of a door frame, and a latch arm device affixed to a corner edge of the door.

[0034] Figure 2B is a cross-sectional view of the lock box and latch arm of Figure 2 A.

[0035] Figure 3 is a frontal perspective view of the self-latching lock box of the present invention with a latch arm device in the latched position.

[0036] Figure 4 is an exploded rear perspective view of the self-latching lock box of the present invention with a latch arm device in the latched position.

[0037] Figure 5 is a cross-sectional view invention in the closed position.

of the self-latching lock box of the present [0038] Figure 6 is a cross-sectional view invention in the open position.

of the self-latching lock box of the present [0039] Figure 7 is a cross-sectional view invention returning to the closed position.

of the self-latching lock box of the present present invention in the closed position with the rotatable hooking means preventing the [0040] Figure 8 is a cross-sectional view of the self-latching lock box of the securing tongue from relative movement.

-82019200209 11 Jan 2019

DETAILED DESCRIPTION OF THE INVENTION [0041] The following description refers to specific embodiments of the present invention and is in no way intended to limit the scope of the present invention to those specific embodiments.

[0042] Reference in the specification to “one embodiment”, “another embodiment”, “some embodiments”, or “certain embodiments” means that a particular feature, structure, characteristic, or function described in connection with the embodiment is comprised in at least one embodiment of the invention and may be in more than one embodiment. The appearances of the phrases “in one embodiment”, “in some embodiment”, or “in certain embodiments” in various places throughout the specification are not necessarily all referring to the same embodiment or embodiments.

[0043] Where the terms “comprise”, comprises”, “comprising”, “comprise”, “comprises”, “comprised” or “comprising” are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more other feature, integer, step, component or group thereof.

[0044] Further, any prior art reference or statement provided in the specification is not to be taken as an admission that such art constitutes, or is to be understood as constituting, part of the common general knowledge.

[0045] As used herein, the term “abutment” means any structure for resisting a frictional force. Non-limiting examples of an abutment are a slot, a protrusion and a surface against which an item may rest or bear.

[0046] Also, the indefinite articles “a” and “an” preceding an element or component of the invention are intended to be non-restrictive regarding the number of instances (i.e.

occurrences) of the element or component. Therefore “a” or “an” should be read to comprise one or at least one, and the singular word form of the element or component also comprises the plural unless the number is obviously meant to be singular.

-92019200209 11 Jan 2019 [0047] Referring to Figures 1A, IB, 2A and 2B, and as best shown in Figure 1A, the selflatching lock box 100 is affixed to the door frame 104 adjacent the door leaf 105 comprising a latch arm 140. The lock box 100 is arranged to latch automatically when the door leaf 105 is closed to prevent the door leaf 105 from being reopened without release of the latch arm 140. Typically, in the case of a fire door, the door leaf 105 is mounted to the door frame 104 on hinges 106 (not shown) and biased towards the closed position.

[0048] Figures 3 and 8 illustrate the components of the lock box.

[0049] As can be seen, the lock box 100 comprises a displaceable securing tongue 110 in a lock box housing 101. The securing tongue 110 is slidable in a sleeve 133 comprising the internal walls of the housing 101 and securing block 137. The securing tongue 110 is slidable in the direction of its axis between a closed position 148 and an open position 149, as shown in Figures 5 and 6, respectively. Typically, the housing 101 and the sleeve 133 (i.e., the internal walls of the housing 101 together with securing block 137) are formed from metal or alloy (such as 316 SS). The sleeve 133 allows the securing tongue to be positioned therein as a free sliding fit. The securing block 137 and the internal walls of the housing 101 guide the securing tongue 110 in the direction of its axis between its closed position 148 and its open position 149. Cover plate 143 covers the internal components of the lock box 100 and also acts to secure the securing block 137 in position to form the sleeve 133.

[0050] The securing tongue 110 incorporates an abutment 114 such as a slot, adapted to receive a hook 126 of a rotatable hooking means 120. The slot 114 and hook 126 form a frictional relationship to prevent relative movement of the securing tongue 110. Figures 3 to 8 illustrate the abutment 114 as a slot. In this embodiment, the slot 114 and hook 126 are compatibly shaped and sized to be mateable with each other.

[0051] A compression spring 111 is located between the securing tongue 110 and the housing 101 to bias the securing tongue 110 towards the closed position 148. One of the ends of the compression spring 111 is attached to the base 115 of the securing tongue 110. The other end of the compression spring 111 is nested against

-102019200209 11 Jan 2019 the internal width-wise wall of the housing 101. Spring guides 135 are located on each length-wise internal wall to guide the compression and expansion of spring

111. The sleeve 133 formed with the securing block 137 creates a space to contain the spring 111.

[0052] The latch arm 140 is arranged to travel along a latching pathway 144 for receiving the latch arm 140 at the latching mouth 136 by displacing the displaceable securing tongue 110 momentarily from the closed position 148 to the open position 149. The securing tongue 110 is forced into the open position 149 as the latch arm 140 strikes against the strike face 112 of the securing tongue 110 to expose the latching mouth 136.

[0053] The rotatable hooking means 120 is rotatable about an axis 132 located substantially intermediate its length. The hooking means 120 comprises a shoulder lever 123 and a hooking lever 125, where levers 123, 125 are rotatably joined at their respective proximal ends 122, 139 about axis 132.

[0054] The shoulder lever 123 has a distal shoulder lever end 121 and a proximal shoulder lever end 122. The distal shoulder lever end 121 comprises a chamfered shoulder 124. The chamfer shoulder 124 assists in receiving the latch arm 140 to locate into the latching mouth 136 as the latch arm 140 is being moved from the retracted position 142 (not shown) to the extended position 141. It would be understood that when the distal shoulder lever end 121 comprises two chamfered shoulders 124, the lock box 100 is advantageously universally installable in either left- or rightorientations to receive a latch arm 140 attached to either a left-hand or right-hand opening doors.

[0055] The hooking lever 125 has a distal hooking end 138 and a proximal hooking lever end 139. As illustrated in figures 5 to 8, a hook 126 is located at the distal hooking lever end 138.

[0056] A first mainspring 128 (not shown) is located at proximal shoulder lever end 122 about axis 132 to bias distal shoulder lever end 121 towards the strike face 112 of the securing tongue 110. A second mainspring 129 (not shown) is located at proximal hooking lever end 139 about axis 132 to bias distal hooking lever end 138

-11 2019200209 11 Jan 2019 away from slot 114 of the securing tongue 110. In some embodiments, the springs 128,129 (not shown) may each be a torsion spring.

[0057] The biasing forces resulting from mainsprings 128, 129 ensures that the distal hooking lever end 138 is continuously biased away from slot 114 of the securing tongue 110 such that when shoulder lever 123 rotates upon receipt of latch arm 140 inside the latching mouth 136, the distal hooking lever end 138 is urged towards the slot 114 of the securing tongue 110 and allow hook 126 to engage the slot 114 and prevents relative movement of the securing tongue 110.

[0058] Although the hooking means 120 is illustrated as being comprised of a shoulder lever 123 and a hooking lever 125, it should be appreciated that that levers 123, 125 of the hooking means 120 could easily be incorporated as an integral part arranged to pivot about an axis located intermediate its length.

[0059] Once the latch arm 140 is in the latching position 146, and positioned within the latching mouth 136, the latch arm-receiving shoulder lever 123 rotates, which in turn rotates the hooking lever 125 to urge the hook 126 into the slot 114. The hooked slot 114 prevents relative movement of the securing tongue 110 and maintained in the closed position 148.

[0060] In order to open the door leaf 105, the latch arm 140 is manually pulled into its retracted position 142 (not shown) where the latch arm is remote from the latching mouth 136. Once in this position, the door leaf 105 is then free to be opened.

[0061] The occupiable area inside the latching mouth 136 by the latch arm 140 is arranged to be larger than the cross-sectional area of the latch arm 140. With this arrangement, the latching mouth 136 is suitably sized to receive the latch arm 140 within the mouth 136 as the latch arm 140 travels along the latching pathway 144 and passes the securing tongue 110. As the securing tongue 110 is biased towards the closed position 148, the latch arm 140 will strike the strike face 112 of the securing tongue 110 to force the securing tongue 110 to the open position 149. Consequently, the latch arm 140 is able to pass the securing tongue 110 and position in the latching position 146 within the latching mouth 136.

- 122019200209 11 Jan 2019 [0062] The strength of the biasing force towards the closed position 148 by the securing tongue 110 can be set by choosing an appropriate compression spring 111 suitable for the desired application. In this situation, an appropriate compression spring 111 with a desired compressional load force based on the gauge of the spring wire (i.e., wire diameter), pitch distance, free length, and/or outside diameter, can be selected to provide a desired compressional bias. In this way, the compressional strength of the spring 111 used can be selected based on the free weight of the door leaf 105 such that the securing tongue 110 can be displaced solely by the force generated by the weight of the door leaf 105. Alternatively, the strength of the biasing force acting towards the closed position 148 can be set such that a force greater than that generated solely by the free weight of the door leaf 105 is required.

[0063] The housing 101 incorporates apertures 102 which are arranged to receive fastening means such as mounting screws 131 (not shown) and the like to affix the housing to the door leaf 105 (or door frame 104), as required.

[0064] The lock box 100 is preferably attached to the door frame 104 at an overhead location as shown in Figures 1 and 2, such that as the door leaf 105 closes, the latching mouth 136 of the lock box 100 is directly over (or substantially aligns with) the axial direction of the latch arm 140 located on the door leaf 105.

[0065] As it is not necessary for the latch arm 140 to be in its retracted position 142 (not shown) to enable the door leaf 105 to be completely closed, the lock box 100 allows the latch arm 140 to be slidably moved to its extended position 141 and engage the latching mouth 136 after the door leaf 105 has been closed.

[0066] The housing 101 may also incorporate a key-enabled locking mechanism 117 (not shown). A key operated rotatable barrel lock 118 (not shown) may be located within the housing 101 and rotation of the barrel lock 118 causes a sliding movement of a pin 119 (not shown) into or out of engagement with a slot 114 located in the securing tongue 110. Once the pin 119 is in engagement with the slot 114, the pin 119 prevents the displacement of the securing tongue 110 and is locked in the closed position 148.

[0067] Other embodiments and uses of this invention will be apparent to those having ordinary skill in the art upon consideration of the specification and figures of the

- 13 2019200209 11 Jan 2019 invention disclosed herein. The specification and specific example given should be considered exemplary only, and it is contemplated that the appended claims will cover any other such embodiments or modifications that fall within the scope of the invention disclosed herein.

Claims

The Claims defining the invention are as follows:

1. A self-latching lock box comprising a displaceable securing tongue adapted to be momentarily displaced upon receiving a latch arm for latching thereto, wherein the latch arm is releasable from the lock box without displacing the securing tongue.
2. The self-latching lock box of claim 1, wherein the securing tongue is biased towards a closed position.
3. The self-latching lock box of claim 1 or claim 2, wherein the securing tongue is biased with a compression spring.
4. The self-latching lock box of any one of claims 1 to 3, wherein the securing tongue comprises a strike face.
5. The self-latching lock box of any one of claims 1 to 4, wherein the securing tongue comprises a slot.
6. The self-latching lock box of claim 5, comprising a rotatable hooking means adapted to hook into the slot to prevent relative movement of the securing tongue.
7. The self-latching lock box of claim 6, wherein the rotatable hooking means comprises a latch arm-receiving shoulder lever and a hooking lever comprising a hook, the levers being rotatably joined about their proximal ends.
8. The self-latching lock box of claim 7, wherein the latch arm-receiving shoulder lever is biased towards the securing tongue and the hooking lever is biased away from the slot.
9. The self-latching lock box of claim 6 or claim 7, wherein the latch arm-receiving shoulder lever comprises at least one chamfered shoulder.
10. The self-latching lock box of claim 6 or claim 7, wherein the latch arm-receiving shoulder lever comprises two chamfered shoulders.
11. A kit of parts comprising (i) a latch arm; and (ii) a lock box according to any one of claims 1 to 10, wherein the kit of parts in use provides a self-latching device for latching in a pre-determined latching position which are otherwise moveable

- 15 2019200209 11 Jan 2019 relative to one another along a latching pathway when affixed to a door leaf and door frame, respectively, the parts being arranged such that when the latch arm is received by the lock box comprising a displaceable securing tongue in the predetermined latching position, relative movement of the displaceable securing tongue is prevented.