AU2023251488A1

AU2023251488A1 - A latch assembly

Info

Publication number: AU2023251488A1
Application number: AU2023251488A
Authority: AU
Inventors: Craig Stuart Murray
Original assignee: Assa Abloy Australia Pty Ltd
Current assignee: Assa Abloy Australia Pty Ltd
Priority date: 2022-10-19
Filing date: 2023-10-19
Publication date: 2024-05-16

Abstract

This invention relates to a latch assembly 3 for mounting to a door panel 1 to interact with a strike plate 8 mounted to a doorjamb 2. The latch assembly 3 includes 5 a bolt 6 that is adjustable between a latch condition and a release condition including a head 18 and at least one arm 21 which is pivotable relative to the head 18 as the bolt 6 adjusts between the latch condition and the release condition. <filename> 0Q0 Coo CDm NI Lr)) (L.D r-H-

Description

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Title of Invention

A latch Assembly

[0001] This application claims priority from Australian Patent Application 2022903080 filed on 19 October 2022, the entire contents of which are to be taken as incorporated herein by this reference.

Technical Field

[0002] The invention relates to a latch assembly for a door panel installed to swing between an open condition and a closed condition relative to a strike plate on a door jamb. More specifically the latch assembly includes a bolt assembly with a head, that is adapted to move in longitudinal plane between an extended position and a retracted position, and a biasing means adapted to bias the bolt assembly towards the extended position. The applicant has developed the latch assembly so that the bolt assembly adjusts from a latch condition towards a release condition on moving the door panel relative to the door jamb. However, the invention is not limited to this application as the latch assembly may also be suitable for use with actuating door furniture or door locks that retract or unlock the bolt assembly before moving the door from the closed position.

Background of Invention

[0003] The following discussion of the background to the invention is intended to facilitate an understanding of the invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was published, known or part of the common general knowledge as at the priority date of the application.

[0004] The function of a latch assembly is to temporarily retain a door panel in a closed position relative to a doorjamb. The latch assembly will generally include a bolt that is adjustable between an extended position and a retracted position relative to a strike plate fitted to the door jam, and a spring that biases the latch towards the extended position. The bolt is generally considered to be in a latch condition when it is in the extended position and engaging the strike plate, and a release condition when it is in the retracted position and disengaged from the strike plate. The adjustment between the extended position and the retracted position can be by way of an actuating knob or lever fitted to the door. This is particularly the case where the bolt has a head with a bevelled leading surface. Alternatively in the case of a roller or ball latch the movement of the door from the closed position towards the open position will move the roller or ball away from the extended position towards the retracted position.

[0005] When the roller or ball latch is installed, it is generally arranged such that the arc of the roller or ball protrudes to engage with a complementary surface on the strike plate to hold the door in the closed position. The spring will have sufficient force that with the roller or ball in the extended position the door will be inhibited from moving from the closed position until a person applies sufficient force to the door. The shape of the roller or ball is such that when sufficient force is applied to the door, the vector of force acting on the roller or ball urges it to retract rather than prevent to the door from opening in say a single bevel latch bolt. The roller or ball can only have a limited throw or projection otherwise the user can have the feeling that the door is stuck in its closed position.

[0006] One issue with a roller or ball latch is that it only has a small tolerance for the gap between the door panel and the door jamb otherwise the roller or ball fails to seat within the complementary surface. This can result if the door panel is poorly installed, or if there is warping of the door panel, or movement in the foundations over time that increase the gap. Where this happens the door panel can rattle within the door jamb or fail to inhibit the door from moving from the closed position say in the case of a breeze. In some cases, the roller or ball latch acts as a secondary security device for locating the primary security device such as an electric drop bolt. Where the roller or ball catch fails to accurately locate within the strike plate the drop bolt can fail to securely locate in its own strike plate.

Summary of Invention

[0007] It ought to be appreciated that despite all efforts of the installer door frames and door panels adjust overtime, door hinges move and the gap between the door panel and the door jamb can change over its working life. In view of the this, it is desirable to provide a latch assembly that allows for some tolerance in movement whilst remaining serviceable.

[0008] Before turning to a summary of the invention, it is useful to provide an explanation of some of the terms that will be used to define the spatial relationship of various parts thereof. In this respect, spatial references throughout this specification will generally be based upon the latch assembly in an installed orientation in the door panel. For convenience, terms such as "vertical", "lateral' and "longitudinal" are to be interpreted in this context relative to the door panel.

[0009] According to an aspect of the present invention there is provided a latch assembly for a door panel installed to swing between an open condition and a closed condition relative to a strike plate on a door jamb, the latch assembly including a housing adapted for attachment to an edge of the door panel, a bolt assembly that is adjustable relative to the housing between a latch condition and a release condition when installed, the bolt assembly including a head that is adapted to move in longitudinal plane between an extended position and a retracted position, a biasing means adapted to bias the head towards the extended position, at least one arm that is adapted for movement with the head so as to be pivotable relative thereto, such that when the head is in the retracted position the arm is substantially aligned with the longitudinal plane to adopt an aligned position, and when the head is moved towards the extended position the arm moves laterally relative to the longitudinal plane to adopt a lateral position.

[0010] While the bolt assembly can function with a single arm, particularly where the door panel is accurately attached to a doorjamb with a soffit which the door panel abuts when in a closed position, it is preferred that bolt assembly includes two arms, each arm being adapted to move laterally of the longitudinal plane in opposed directions when the head is in the extended position. This facilitates centrally locating the bolt assembly relative to the strike plate and can also make the latch assembly more suitable for location on a swing through door panel fitted to a doorjamb without a soffit.

[0011] It is preferred that each arm includes a pivot axis about which the arm pivots laterally when the head moves between the retracted position and the extended position. It is further preferred that each pivot axis is laterally offset from the longitudinal plane. It is still further preferred that each pivot axis is laterally offset from the longitudinal plane in an opposite direction to a direction in which each head moves laterally. It is preferred that each arm pivots through no more than 450, as this arrangement minimises the forces acting on each arm during the movement from the lateral position to the aligned position.

[0012] It is further preferred that each arm is adapted to interact with the head so as to be vertically offset from each other, as this arrangement provides a slimline bolt assembly. It is further preferred that the at least one arm is adapted to interact with the head and with the housing such that once in the aligned position the at least one arm moves in the longitudinal plane with the head to the retracted position. It is preferred that the at least one arm includes an abutment formation, and the housing includes at least one stop formation, the abutment formation being adapted to abut said stop formation when the head moves between the retracted position and the extended position so as to initiate the lateral movement of the arm of the arm. The formation preferably includes a first abutment surface and a second abutment surface that is substantially opposed to the first abutment surface, the stop formation includes an inner surface and an outer surface, the first abutment surface being adapted to engage the inner surface as the head moves away from the from retracted position towards the extended position and the second abutment being adapted to engage the outer surface as the head moves away from the extended position towards the retracted position.

[0013] The housing preferably includes a base and a face plate wherein the faceplate includes the stop formation wherein the face plate is adapted such that the inner surface and the outer surface are on opposed sides of the faceplate. It is preferred that the head is adapted with at least one shoulder to interact with the faceplate so as to limit movement of the head relative to the faceplate at the extended position.

[0014] The abutment formation is preferably adapted such that the first abutment surface and the second abutment surface engage the inner surface and outer surface respectively when the head is in the extended position.

[0015] The at least one arm preferably includes tip having a bevel surface with an apex that is substantially aligned with the longitudinal plane when the at least one arm is in the aligned position, and the bevelled surface is substantially parallel with the longitudinal plane when in the lateral position. The bevelled surface is preferably no more than 150 from exactly parallel with the longitudinal plane. It is further preferred that the bevelled surface at the tip of the arm is a double bevelled surface having a leading bevelled surface and a trailing bevelled surface whereby the leading bevelled surface is no more than 150from exactly parallel with the longitudinal plane. The double bevelled surface is preferably adapted with an internal angle of no less than 90°. It is still further preferred that the head includes a at least one nose having a double bevel surface with an apex that is substantially aligned with the longitudinal plane, however the nose may have a bull nose formation. The or each nose of the head is preferably adapted with an internal angle of no less than 900. It is further preferred that the head includes a plurality of said noses, each nose spaced by said at least one arm. It is further preferred that the or each arm is adapted for interaction with the strike plate so that moving the door panel from the closed condition towards the open condition results in movement of the or each arm from the lateral position towards the aligned position. It is further preferred that the head is adapted for interaction with the strike plate so that moving the door panel from the closed condition towards the open condition results in movement of the head from the extended position towards the retracted position. It is further preferred that the bolt assembly is adapted to include a body that is fastened to the head so as to move therewith, the body being adapted to accommodate the biasing means. It is further preferred that the housing is adapted to accommodate the body so as to limit movement of the body relative to the housing to movement in the longitudinal plane. It is further preferred that the bolt assembly is adapted for interaction with the strike plate such that it adjusts from the latch condition towards the release condition on moving the door panel relative to the doorjamb.

Brief Description of Drawings

[0016] In order that the invention may be more fully understood, some embodiments will now be described with reference to the figures in which:

[0017] Figure 1 is an isometric view of a door panel and door jamb with a preferred embodiment of the latch assembly when installed.

[0018] Figure 2 is an isometric view of an alternate perspective of the door panel and doorjamb from figure 1 illustrating a strike plate when installed.

[0019] Figure 3 is an isometric view of a latch assembly and strike plate according to a preferred embodiment of the invention.

[0020] Figure 4 is an is an exploded isometric view of the latch assembly and strike plate from figure 3.

[0021] Figure 5 is an isometric view of an alternate perspective of the latch assembly and strike plate from figure 4.

[0022] Figure 6 is a front elevation view of the face plate from figure 4.

[0023] Figure 7 is a cross sectional view through the door panel and doorjamb from figure 1 showing the head in an extended position and the arms in a lateral position.

[0024] Figure 8 is a cross sectional view of the latch assembly from figure 7 with the door panel moved towards a closed position with the head in a retracted position and the arms in an aligned position.

[0025] Figure 9 is a cross sectional view of the latch assembly from figure 7 with the door panel in the closed position with the head in the extended position and the arms in the lateral position with the bolt assembly engaging the strike plate adopting a latch condition.

Detailed Description

[0026] Figures 1 and 2 generally illustrate a door panel 1 positioned in an open condition relative to a doorjamb 2. A latch assembly 3 is illustrated attached to the door panel 1 by a pair of screws 4a, 4b extending through a face plate 5. Figure 1 also illustrates a bolt assembly 6 protruding from the face plate 5. Figure 1 also illustrates a door handle 7 that is primarily provided for moving the door panel 1 between a closed position (see figure 9) and the open conditioned illustrated in figure 1. The door handle 7 may also be suitable for adjusting the condition of the bolt assembly 6 from a latched condition (see figure 9) to a retracted position (see figure 8), however the manner in which the door handle 7 may interact with the latch assembly 3 is not described in this specification.

[0027] Figure 2 illustrates a strike plate 8 attached to the door jamb 2 by way of a pair of screws 9a, 9b. The strike plate 8 defines a void 10 to accommodate the bolt assembly 6 when the door is in a closed condition.

[0028] Figures 1 and 2 illustrate the door panel 1 and doorjamb 2 of the type that would be used for a door panel 1 that swings between an open condition and a closed condition. The door jamb illustrated is of the form having a single soffit 11 which the door panel 1 abuts when in the closed condition. However the latch assembly 3 the subject of the invention is also suitable for use with door jams 2 without a soffit 11 so that the door panel 1 can swing through either side of the door jamb 2. Whilst figure 2 illustrates the strike plate 8 having a single ramp 12, an alternate form of strike plate 8 maybe required having ramps 12 on opposed sides thereof.

[0029] Figure 3 illustrates the latch assembly 3 having a housing 13 which includes the combination of the face plate 5, a base 14 and a cover 15. The cover 15 is attached to the base 14 by way of a plurality of screws 16a, 16b, 16c and 16d. Whilst the face plate 5 is attached to the base 14 by a pair of screws 17a, 17b (see figure 4).

[0030] Referring generally now to figures 4 and 5 which illustrate the latch assembly 3 in an exploded view such that the face plate 5 is detached from the base 14, and the cover 15 is detached from the base 14. The bolt assembly 6 illustrated includes a head 18 and a body 19 attached thereto by a screw 20. The bolt assembly 6 also includes a pair of arms 21a and 21b which are attached to the head 18 by a pair of pins 22a, 22b. The pins 22a, 22b are attached to the head 18 in a manner offset from a longitudinal plane that will be explained later in the specification.

[0031] A biasing means in the form of a compressions spring 23 is provided for urging the head towards an extended position. Figure 5 illustrates the body 19 being formed with a cavity 24 to capture the spring 23. It ought to be appreciated that the spring 23 acts between the base 14 and the body 19. It should also be appreciated from figure 5 that the base 14 includes a first slot 25 having a width to accommodate the width of the body 19 and a second slot 26 having a width to accommodate the width of the head 18. This interaction of the head 18 with the first slot 25, and the body 19 with the second slot 26 encourages linear movement of the bolt assembly 6 relative to the housing 13.

[0032] Figure 4 illustrates the head 18 being formed within an upper and lower shoulder 27a, 27b which are adapted to abut a rear surface of face plate 5 when the head 18 is in an extended position (see figure 1), so as to capture the bolt assembly 6 within the housing 13.

[0033] Figure 4 also illustrates the head 18 being formed with 3 noses 28a, 28b and 28c each being formed with a double bevel leading surface. The double bevel arrangement allows for the latch assembly 3 to be installed in a door panel 1 intended to swing through the doorjamb 2, or on either aleft hand opening or right hand opening door panel 1 without having to change the orientation of the latch assembly 3 relative to the door panel 1.

[0034] Figure 4 also illustrates each of the arms 21a, 21b having a tip 29a, 29b also being formed with a double bevel leading surface. Whilst a double bevelled leading surface on the tips 29a, 29b is illustrated, for reasons that will become apparent later in the specification only a single bevel is required.

[0035] Figure 5 illustrates each arm 21a, 21b being formed within am abutment formation 30a, 30b, with each abutment formation having a first abutment surface 31a, 31b and a second abutment surface 32a, 32b the housing 13, and more specifically the face plate 5 includes a pair of stop formations 33a and 33b that are adapted to interact with the abutment formations 30a and 30b respectively. More specifically as illustrated in figure 5 the stop formations 33a and 33b have an inner stop surface 34a and 34b, and illustrated in figure 4 an outer stop surface 35a, 35b. Figure 6 more clearly illustrates the stop formations 33a, 33b, and in particular the outer stop surfaces 35a, b. The inner stop surfaces 34a, 34b are on the inner side of the face plate 5 which are obscured in figure 6.

[0036] Figure 7 illustrates the door panel 1 in an open condition slightly spaced from a doorjamb 2. The arm 21a is positioned adjacent the ramp 12 of the strike plate 8, the head 18 is in an extended position with the apex of the nose 28b aligned with a longitudinal plane X-X which extends through the latch assembly 3. Figure 7 illustrates the pin 22b about which the arm 21b pivots. The pin 22a (see figure 5) about which the arm 21a pivots is similarly offset from the longitudinal plane on an opposed side thereof. Both the pins 22a, 22b effectively define an axis (herein after referred to as axis A and axis B). Figure 7 illustrates the arms 21a and 21b projecting laterally form the head 18 in what is considered to be a lateral position. When the arms 21a, 21b are in the lateral position, the leading bevelled surface 36a, 36b at the tip 29a, 29b is considered to be substantially parallel with the longitudinal plane X-X. For the purposes of the specification the term "substantially parallel" is considered to include no more than 150 from exactly parallel with the longitudinal plane X-X.

[0037] Figure 7 also illustrates the first abutment surface 31b of the arm 21b engaging the inner stop surface 34b is to be understood that the arm 21a is similarly arranged. In an alternative embodiment, not shown, the arm 21b be further rotated so that both the first abutment surface 31b and second abutment surface 32b engage both the inner stop surface 34b and outer stop surface 35b at the same time when the door is in an opened position.

[0038] When comparing figure 7 with figure 8 it should be understood that the door panel 1 has moved from the open condition shown in figure 7 towards a closed condition, with the closed position shown in figure 9. Movement of the door panel 1 in this manner has caused the arm 21a (see figure 7) to engage the strike plate 8 causing it to pivot about the pin 22a. Further movement of the door panel continues with the pivoting of the arm 21a (see figure 4) causing the first abutment 31a to lever off the inner stop surface 34a causing retraction of the head 18 from the extended position illustrated in figure 7 to a retracted position in figure 8. To the extent that the head 18 engages the ramp 12, the bevelled surfaces at noses 28a, 28b and 28c can also facilitate movement of the head from the extended position to the retracted position. The position of the arm 21b as shown in figure 8 is aligned with the head 18 and herein after referred to as the aligned position. It ought to be appreciated that the arm 21a (obscured in figure 8) is similarly in the aligned position. Furthermore, it should be appreciated from figure 8 that the tip 29b (and the 29a obscured in figure 8) is aligned with the longitudinal plane X-X when the arms 21a and 21b are in the aligned position. Furthermore, it can be appreciated from figure 8 that the double bevelled surfaces of the tip 29b, and nose 28b (see figure 7) include an internal angle which is no less than 900.

[0039] Comparing now figure 8 with figure 9 which illustrates the door panel 1 in a closed condition engaging the soffit 11 of the door jamb2. In this position the arms 21a, 21b and head 18 project into the void 10 with each arm 21a, 21b adopting the lateral position, or as close the lateral position as the dimensions of the void 10 will allow. It should be noted that each arm 21a, 21b is engaging the strike plate 8 so as to firmly secure the door panel 1 in the closed position. It should also be noted that the second abutment surfaces 32a, 32b are spaced from the outer stop surfaces 35a, 35b due to the engagement of the arms 21a, 21b with the strike plate 8. Furthermore it should be noted from figure 9 that the leading bevelled surfaces 36a, 36b are substantially parallel with the longitudinal plane X-X, although less "substantially parallel" than that illustrated in figure 7. It ought to be appreciated from figure 9 that where the gap between the door panel 1 and the strike plate 8 adjusts over the operating life of the door panel, the arms 21a and 21b will continue to engage the strike plate 8 allowing for greater tolerance than may be otherwise provided with a roller or ball catch.

[0040] Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

Claims

The claims defining the invention are as follows:

1. A latch assembly for a door panel installed to swing between an open condition and a closed condition relative to a strike plate on a door jamb, the latch assembly including a housing adapted for attachment to an edge of the door panel, a bolt assembly that is adjustable relative to the housing between a latch condition and a release condition when installed, the bolt assembly including a head that is adapted to move in longitudinal plane between an extended position and a retracted position, a biasing means adapted to bias the head towards the extended position, at least one arm that is adapted for movement with the head so as to be pivotable relative thereto, such that when the head is in the retracted position the arm is substantially aligned with the longitudinal plane to adopt an aligned position, and when the head is moved towards the extended position the arm moves laterally relative to the longitudinal plane to adopt a lateral position.

2. A latch assembly according to claim 1 wherein the at least one arm includes two arms, each arm being adapted to move laterally of the longitudinal plane in opposed directions when the head is in the extended position.

3. A latch assembly according to claim 2 wherein each arm includes a pivot axis about which the arm pivots laterally when the head moves between the retracted position and the extended position.

4. A latch assembly according to claim 3 wherein each pivot axis is laterally offset from the longitudinal plane.

5. A latch assembly according to claim 4 wherein each pivot axis is laterally offset from the longitudinal plane in an opposite direction to a direction in which each head moves laterally.

6. A latch assembly according to any one of claims 3 to 5 wherein each arm pivots through no more than 45°.

7. A latch assembly according to any one of claims 2 to 6 wherein each arm is adapted to interact with the head so as to be vertically offset from each other.

8. A latch assembly according to any one of the preceding claims wherein the at least one arm is adapted to interact with the head and with the housing such that once in the aligned position the at least one arm moves in the longitudinal plane with the head to the retracted position.

9. A latch assembly according to any one of the preceding claims wherein the at least one arm includes an abutment formation, and the housing includes at least one stop formation, the abutment formation being adapted to abut said stop formation when the head moves between the retracted position and the extended position so as to initiate the lateral movement of the arm of the arm.

10. A latch assembly according to claim 9 wherein the abutment formation includes a first abutment surface and a second abutment surface that is substantially opposed to the first abutment surface, the stop formation includes an inner surface and an outer surface, the first abutment surface being adapted to engage the inner surface as the head moves away from the from retracted position towards the extended position and the second abutment being adapted to engage the outer surface as the head moves away from the extended position towards the retracted position.

11. A latch assembly according to claim 10 wherein the housing includes a base and a face plate wherein the faceplate includes the stop formation wherein the face plate is adapted such that the inner surface and the outer surface are on opposed sides of the faceplate.

12. A latch assembly according to claim 11 wherein the head is adapted with at least one shoulder to interact with the faceplate so as to limit movement of the head relative to the faceplate at the extended position.

13. A latch assembly according to claim 11 or 12 wherein the abutment formation is adapted such that the first abutment surface and the second abutment surface engage the inner surface and outer surface respectively when the head is in the extended position.

14. A latch assembly according to any one of the preceding claims wherein the at least one arm includes tip having a bevel surface with an apex that is substantially aligned with the longitudinal plane when the at least one arm is in the aligned position, and the bevelled surface is substantially parallel with the longitudinal plane when in the lateral position.

15. A latch assembly according to claim 14 wherein the bevelled surface is no more than 15° from exactly parallel with the longitudinal plane.

16. A latch assembly according to claim 15 wherein bevelled surface at the tip of the arm is a double bevelled surface having a leading bevelled surface and a trailing bevelled surface whereby the leading bevelled surface is no more than 15° from exactly parallel with the longitudinal plane.

17. A latch assembly according to claim 16 wherein the double bevelled surface is adapted with an internal angle of no less than 90°.

18. A latch assembly according to any one of the preceding claims wherein the head includes a at least one nose having a double bevel surface with an apex that is substantially aligned with the longitudinal plane.

19. A latch assembly according to claim 18 wherein the or each nose is adapted with an internal angle of no less than 90°.

20. A latch assembly according to claim 18 or 19 wherein the head includes a plurality of said noses, each nose spaced by said at least one arm.

21. A latch assembly according to any one of the preceding claims wherein the or each arm is adapted for interaction with the strike plate so that moving the door panel from the closed condition towards the open condition results in movement of the or each arm from the lateral position towards the aligned position.

22. A latch assembly according to any one of the preceding claims wherein the head is adapted for interaction with the strike plate so that moving the door panel from the closed condition towards the open condition results in movement of the head from the extended position towards the retracted position.

23. A latch assembly according to any one of the preceding claims wherein the bolt assembly is adapted to include a body that is fastened to the head so as to move therewith, the body being adapted to accommodate the biasing means.

24. A latch assembly according to claim 23 wherein the housing is adapted to accommodate the body so as to limit movement of the body relative to the housing to movement in the longitudinal plane.

25. A latch assembly according to anyone of the preceding claims wherein the bolt assembly is adapted for interaction with the strike plate such that it adjusts from the latch condition towards the release condition on moving the door panel relative to the doorjamb.

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