AU782549B2 - A lock for a sliding door - Google Patents

Description

S&F Ref: 522642

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name and Address of Applicant: Gainsborough Hardware Industries Limited 190 Whitehorse Road Blackburn Victoria 3130 Australia Actual Inventor(s): Address for Service: Invention Title: Geoffrey James Fortune Spruson Ferguson St Martins Tower 31 Market Street Sydney NSW 2000 A Lock for a Sliding Door ASSOCIATED PROVISIONAL APPLICATION DETAILS [33] Country [31] Applic. No(s) AU PQ5511 [32] Application Date 09 Feb 2000 The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5815c A LOCK FOR A SLIDING DOOR Field of the Invention The present invention relates to a lock for a sliding door including, but not restricted to, a cavity sliding door.

Sliding doors are opened and closed in a direction parallel to the face of the door.

Sliding door locks include a bolt with a hook which engages a strike plate to retain the door closed.

Cavity sliding doors slide into a cavity in a wall or door frame until the edge of the door in which the latch is mounted is substantially flush with the wall/door frame and 1o the door is concealed.

Background of the Invention Sliding door locks generally include a face plate mounted flush with a side edge of the door and an actuation lever (or knob) which protrudes from one or both sides of the door. However, such protruding levers (or knobs) can not be used with cavity sliding 15 doors as they prevent the door from completely sliding into the cavity. For this reason, cavity sliding door locks generally include a pair of recessed cups mounted either side of the door, one of the cups housing an actuation lever and the other usually housing an emergency release device.

The lever(s) is/are manually pivotted to extend or retract the bolt from the face 20 plate. A strike plate is mounted opposite the edge of the door and includes an opening complimentary to the bolt.

When the door is closed, the bolt can be extended which causes a hook to extend i from the bolt to engage the strike plate and retain the door in the closed position. To open the door, the bolt is retracted which retracts the hook into the bolt and disengages it from the strike plate.

For cavity sliding doors, a recessed pull tab can also mounted on the door edge containing the face plate. The pull tab pivots out from the door edge so it can be gripped when the door is in the flush or fully open position (and thus the door itself can not be gripped) and used to pull the door towards the closed position.

Sliding door locks generally include a lock bolt of generally rectangular cross section with a major (longer) axis parallel to the side edges of the door and a minor (shorter) axis normal to the bottom and top edges of the door.

1I:DayLib\LIBD]00932.doc:AVS 2 United States Patent Nos. 5816629, 5529351 and 5452928 show cavity sliding door locks in which the hook extends from, and retracts into, the bolt in a direction parallel to the shorter axis of the lock bolt.

A disadvantage of this arrangement is the hook must be made small to be able to s travel within the shorter dimension of the bolt. This requires precise tolerances and assembly and increases manufacturing costs. The small hook also requires accurate positioning of the lock, and thus the door, relative to the strike plate to ensure engagement between the hook and the strike plate.

Further, these locks have a sliding bolt which carries the hook. The hook 1o extends from, and retracts into, the bolt when the rear end of the hook respectively reaches or leaves an aperture of the lock casing. This can lead to jamming of the lock in installations where the bolt can not travel sufficiently to retract the hook before the hook reaches the strike plate, which prevents the necessary further travel.

A further disadvantage of the locks disclosed in these patents is that the bolts 5Is deadlock in the extended locked position. If the door is attempted to be closed with the bolt in the extended position, and the bolt is misaligned with the opening in the strike plate, or the opening is blocked, then the impact of the bolt against the strike plate can damage the lock.

The lock disclosed in United States Patent No. 5816629 also has an integral pull tab pivotally mounted to the distal end of the bolt and of complimentary cross section to the bolt.

The integral pull tab avoids the need to mount two separate components (ie. a latch and a finger pull) to the door. However, a disadvantage of the disclosed pull tab oooo• Sdevice is its very small size (approximately 18 mm by 15 mm) makes it difficult to grip, especially when pulling a heavy or stiff door.

It is an object of the present invention to substantially overcome or at least ameliorate one or more of the above disadvantages.

Summary of the Invention In a first aspect, the present invention provides a lock for a sliding door, the lock comprising: a lock body assembly; a drive member adapted for angular movement about a drive member axis responsive to angular movement of a spindle; [I:\DayLib\LIBD]00932.doc:AVS a hook adapted to extend from the lock body assembly and engage with a strike plate in a first position, extend from the lock body assembly without engaging the strike plate in a second position and retract into the lock body assembly without engaging the strike plate in a third position; and a link member having a first end pivotally connected to the drive member and a second end connected to the hook, wherein, when the hook is in the first position, initial angular movement of the drive member in a first direction causes the hook to pivot to the second position and further angular movement in the first direction causes the hook to slide to the third position, and wherein, when the hook is in the third position, initial angular movement of the drive member in a second direction opposite to the first direction causes the hook to slide to the second position and further angular movement in the second direction causes the hook to pivot to the first position.

The lock body assembly preferably includes a-camming protuberance and the hook preferably includes first and second surfaces adapted for controlled abutment with the protuberance and first and second edges for controlled abutment with the lock body oe assembly, wherein, when the hook is in the first position, the first surface is in abutment with the protuberance, the second surface is free from abutment with the protuberance, the first edge is in abutment with the lock body assembly and the second edge is free from abutment with the lock body assembly to prevent the hook from sliding such that the initial angular movement of the cam member in the first direction causes the hook to pivot S•to the second position in which the first surface is free from abutment with the protuberance, the second surface is free abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from pivoting such that the further angular movement of the drive member in the first direction causes the hook to slide to the third position in which the first surface is free from abutment with the protuberance, the second surface is in abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly, and further wherein when the hook is in the third position, the first surface is free from abutment with the protuberance, the second surface is in abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from [I:\DayLib\LIBD00932.doc:AVS pivoting such that the initial angular movement of the drive member in the second direction causes the hook to pivot to the second position in which the first surface is free from abutment with the protuberance, the second surface is free abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from sliding such that the further angular movement of the drive member in the second direction causes the hook to pivot to the first position in which the first surface is in abutment with the protuberance, the second surface is free from abutment with the protuberance, the first edge is in abutment with the lock body assembly and the second edge is free from 1o abutment with the lock body assembly.

The lock body assembly preferably includes top and bottom surfaces and the first and second edges alternately abut the top and bottom surfaces respectively.

The lock body assembly preferably includes a carriage which defines a bolt. The carriage is preferably slidably mounted in the lock body assembly and the hook is :i Is preferably pivotally mounted to the carriage The hook is preferably biased to the first and third positions by an over centre S• spring between the drive member and the lock body.

In one form, the bolt has a cross section with major and minor axes and the direction of travel of the hook between the first and second positions is substantially parallel to the major axis of the bolt.

In another form, the lock further includes a face plate for mounting to an edge of the door and a pull tab including an opening for passage of the bolt therethrough, wherein the pull tab is pivotally mounted to the face plate at one end for pivoting between a first ooeo• position substantially flush with the door edge and a second position angled with respect to the door edge to facilitate manual gripping of its other end.

In a second aspect, the present invention provides a lock for a sliding door, the lock comprising: a bolt having a cross section with major and minor axes; and a hook adapted to extend from the bolt for engaging with a strike plate and retract into the bolt for releasing from the strike plate, wherein the direction of travel of the hook between the extended and retracted positions is substantially parallel to the major axis of the bolt.

In a third aspect, the present invention provides a lock for a sliding door, the lock comprising: a face plate for mounting to an edge of the door; [I:\DayLib\LIBD]00932.doc:AVS a bolt having an end adapted to extend from the face plate; and a pull tab including an opening for passage of the bolt therethrough, wherein the pull tab is pivotally mounted to the face plate at one end for pivoting between a first position substantially flush with the door edge and a second position angled with respect to the door edge to facilitate manual gripping of its other end.

The pull tab preferably substantially covers the face plate in the first position.

The pull tab desirably includes a gripping flange and the face plate includes a recess to receive the gripping flange when the pull tab is in the first position.

Brief Description of the Drawing 1o Preferred embodiments of the aforementioned aspects of the invention will now be described, by way of examples only, with reference to the accompanying drawings in which: Fig. 1 is a cross sectional side view of an embodiment of a lock in a locked or extended position; Fig. 2 shows the lock of Fig. 1 at the commence of retraction to an unlocked or retracted position; Fig. 3 shows the lock of Fig. 1 in the retracted position; °°Fig. 4 shows the lock of Fig. 1 with a pull tab in an angled position; and Fig. 5 is a partial perspective view of the lock of Fig. 1 with the pull tab in a flush position.

Detailed Description of the Preferred Embodiment .i Referring to the drawings, there is shown an embodiment of a lock 10 for a •sliding door 12. The lock 10 is installed in the door 12 within the confines of a 54 mm diameter axial hole 14 and a 22mm radial hole 15, which are industry standards.

The lock 10 includes a face plate 16 which is mounted to a side edge of the door 12 by countersunk screws (not shown) which pass through holes 18 and 20. A lock body assembly 17 extends from the face plate 16 into the door 12. The lock body assembly 17 is essentially a hollow, rectangular parallelipiped with a pair of spaced apart side surfaces 17a (only one shown), an open front end 17b, a closed rear end 17c, a full bottom surface 17d and a partial top surface 17e. A carriage 22 is slidably mounted in the lock body assembly 17 and has an end which acts as a bolt 23. The bolt 23 of the carriage 22 is adapted to extend from the face plate 16 in the extended position shown in Fig. 1 and retract substantially flush with the face plate 16 in the retracted position shown in Fig. 3.

[I\DayLib\LIBD00932.doc:AVS A hook member 24 having a tip 26 on its distal end is pivotally mounted within an internal recess 29 of the carriage 22. The tip 26 has a leading edge 27. A strike plate 28 is mounted to the door frame or wall opposite the edge of the door 12 that contains the latch 10 by countersunk screws (not shown) which pass through holes 30 and 32. The strike plate 28 includes an opening 34 of substantially complimentary size to the end 23 (ie. the bolt) of the carriage 22. The opening 34 has an upper edge When the door 12 is closed and the carriage 22 is extended, the tip 26 extends from the extended carriage 22 (as will be explained in more detail below) to a first position in engagement with the rear of the strike plate 28 adjacent the opening 34 to retain the lock 10 and thus the door 12 in the closed position, as shown in Fig. 1. The tip 26 retracts into the carriage 22 in the initial stage of retraction of the carriage 22 for door opening (as will also be explained in more detail below) to a second position, as shown in Fig. 2. The tip 26 remains retracted in the carriage 22 when the carriage 22 is fully retracted into the lock body assembly 17 (as will also be explained in more detail below) 15 to a third position, as shown in Fig. 3.

The lock 10 also includes a drive shaft 44 with an interior cross shaped recess adapted to engage with a pair of flat spindle shafts (not shown) which extend from each of an external actuation lever 48 (see Fig. 5) and an external emergency release device .o.o (not shown). The lever 48 and emergency release device are accommodated within recessed cups 50 which are mounted flush with the sides of the door 12 The drive shaft 44 is non-rotatably connected to a drive member 52. The drive member 52 is pivotally connected by shaft 54 to one end of a link member 56. The other end of the link member 56 is pivotally connected by shaft 58 to the lower proximal end of the hook member 24. The upper proximal end of the hook member 24 is pivotally mounted in the recess 29 of the carriage 22 by shaft An over centre spring 53 is mounted between the drive member 52 and the distal end of the lock body assembly 17. The lock body assembly 17 has a camming protuberance 62 and the hook member 24 has first (upper) and second (lower) edges 64 and 66 and first and second surfaces 70 and 71.

The operation of the lock 10 will now be described. In Fig. 1, the lock 10 is shown in the first or extended position. The lock 10 is biased to this position by the over centre spring 53. Angular movement of the actuation lever 48 and thus the drive shaft 44 in a clockwise direction causes corresponding angular movement in the drive member 52 which drives the shaft 54 upwards towards the position shown in Fig. 2. The first surface 70 of the hook member 24 abuts the protuberance 62 in this position which prevents [I:\DayLib\LIBD]00932.doc:AVS sliding movement. The movement of the drive member 52 draws the link member 56 towards the drive shaft 42 and causes the hook member 24 to pivot to the second position shown in Fig. 2. This frees the tip 26 of the hook member 24 from engagement with the strike plate 28 and allows the door to be slid to the right, relative to Figs. 1 to 3, and opened.

Further pivotting movement of the hook member 24 is prevented by the abutment of the second edge 66 with the lock body assembly bottom surface 17d.

Additional angular movement of the cam member 54 causes the second surface 70 of the hook member 24 to slide to the third position shown in Fig. 3. In this position, the hook 1o member 24 is retracted into the lock body assembly 17 and the tip 26 does not protrude from the edge of the door 12.

The spring 53 also passes its over centre position when moving from the first position (Fig. 1) to the third position (Fig.3) and thus biases the carriage 22 and the hook member 24 to the third position.

s In Fig. 3, the carriage 22 and the hook member 24 are retracted into the lock body assembly 17. Rotating the drive shaft 44 in a counter clockwise direction from the position shown in Fig. 3 causes a reverse of the above operations. More particularly, in the third position the second surface 71 is in abutment with the protuberance 62 which prevents pivotting movement of the hook member 24. Accordingly, initial counter clockwise angular movement of the actuation lever 48, and thus the drive member 52, causes the link member 56 and thus the hook member 24, to slide to the left, relative to Figs. 1 to 3, to the second position shown in Fig. 2. When the hook member 24 reaches the second position shown in Fig. 2 the first and second surfaces 70 and 71 are free from oeooo Sabutment with the protuberance 62 and the first edge 64 abuts the lock body assembly top surface 17e to prevent further pivotting. Accordingly, further counter clockwise angular movement of the cam member 52 causes the hook member 24 to pivot relative to the carriage 22 to the first or extended position shown in Fig. 1.

The primary advantage of the lock 10 is the hook member 24 is positively driven between the extended and retracted position and is thus less prone to jamming than prior art devices.

The over centre spring 53 also provides advantages. Firstly, if the bolt 22 is extended to the position shown in Fig. 1 whilst the door is open and then slid into the strike plate 28, the spring 53 allows movement of the hook member 24, the link member 56 and the drive member 52 so the tip 26 can retract into the carriage 22 as the leading edge 27 of the tip 26 rides over the upper edge 35 of the opening 34. The spring 53 then [I:\DayLib\LIBD]00932.doc:AVS returns the tip 26 to the extended position shown in Fig. 1 after it has fully passed through the opening 34. This advantageously allows the door 12 to be closed regardless of whether the carriage 22 is extended or retracted.

Secondly, the spring 53 is the only component that biases the carriage 22 in the s extended position. If a force is applied to the carriage 22 in its unlocking direction of travel towards the edge of the door 12 that is sufficient to overcome the over centre force of the spring 53, then the carriage 22 and the hook member 24 retract to the position shown in Fig. 3. Accordingly, if an attempt to close the door 12 is made with the carriage 22 extended, and there is misalignment between the carriage 22 and the opening 34 of the 1o strike plate 28 (for example caused by a sagging door) or if the opening 34 is otherwise blocked, then the force of the carriage 22 impacting against the strike plate 38 retracts the carriage 22 without transferring any of that force to the internal components of the lock to avoid damage thereto. This provides an advantage over prior art sliding door locks which deadbolt in the extended position, as they can be damaged when impacted against a strike plate.

Another advantage of the lock 10 is that all of its components, and in particular the hook member 24, pivot about axes that are normal to the major (longer) axis or dimension of the lock bolt. As a result, the tip 26 of the hook member 24 extends from, and retracts into, the carriage 22 along the major axis of the bolt 22. This allows the tip 26 to have a longer travel compared to a hook that travels parallel to the minor axis of the bolt and therefore allows greater variation in manufacturing and assembly tolerances of the lock components themselves and the mounting of the lock and strike plates into the *door. A reduction in manufacturing tolerances is favourably reflected in production costs.

•oooo For cavity sliding door applications, the lock 10 can also, optionally, include a pull tab 36 pivotally mounted to the back plate 16 at its upper edge for rotation about axis 38. The pull tab also includes an opening 39 to allow passage of the bolt 23 therethrough and a gripping flange 40 at its lower edge.

The pull tab 36 is able to pivot between a position substantially flush with the edge of the door 12 when the door 12 is closed, as shown in Fig. 1, and a position angled outwardly from the door to facilitate manual gripping during closing of the door, as shown in Fig. 4. The gripping flange 38 is received within a recessed portion 42 of the face plate 16 when in the flushed position. The recessed portion 42 is sufficiently large to enable a user to insert one or two fingers therein to grip the pull tab 36 in order to pivot it to the position shown in Fig. 4.

[I:\DayLib\LIBD00932.doc:AVS 9 The pull tab 36 is advantageous because it is relatively very large compared to the integral pull tab of the prior art and is therefore easier to grip when attempting to pull a heavy or stiff door. In particular, the pull tab 36 can be gripped by a number of fingers.

Further, notwithstanding its large size, it still only requires a single component (ie. the face plate 18) to be mounted to the door 12.

Although the invention has been described with references to a specific example, it would be appreciated by those skilled in the art that the invention may be embodied in many other forms.

[I:\DayLib\LIBD00932.doc:AVS

Claims (9)

1. A lock for a sliding door, the lock comprising: a lock body assembly; a drive member adapted for angular movement about a drive member axis responsive to angular movement of a spindle; a hook adapted to extend from the lock body assembly and engage with a strike plate in a first position, extend from the lock body assembly without engaging the strike plate in a second position and retract into the lock body assembly without engaging the 1o strike plate in a third position; and a link member having a first end pivotally connected to the drive member and a second end connected to the hook, wherein, when the hook is in the first position, initial angular movement of the drive member in a first direction causes the hook to pivot to the second position and further angular movement in the first direction causes the hook to slide to the third position, and wherein, when the hook is in the third position, initial angular movement of the drive member in a second direction opposite to the first direction causes the hook to slide to the second position and further angular movement in the second direction causes the S 20 hook to pivot to the first position.

2. A lock as claimed in claim 1, wherein the lock body assembly includes a camming protuberance and the hook includes first and second surfaces adapted for controlled abutment with the protuberance and first and second edges for controlled abutment with the lock body assembly, 25 wherein, when the hook is in the first position, the first surface is in abutment S-with the protuberance, the second surface is free from abutment with the protuberance, the first edge is in abutment with the lock body assembly and the second edge is free from abutment with the lock body assembly to prevent the hook from sliding such that the initial angular movement of the cam member in the first direction causes the hook to pivot to the second position in which the first surface is free from abutment with the protuberance, the second surface is free abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from pivoting such that the further angular movement of the drive member in the first direction causes the hook to slide to the third [I:\DayLib\LIBD]00932.doc:AVS position in which the first surface is free from abutment with the protuberance, the second surface is in abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly, and further wherein when the hook is in the third position, the first surface is free from abutment with the protuberance, the second surface is in abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from pivoting such that the initial angular movement of the drive member in the second direction causes the hook to pivot to the second position in which the first surface is free 1o from abutment with the protuberance, the second surface is free abutment with the protuberance, the first edge is free from abutment with the lock body assembly and the second edge is in abutment with the lock body assembly to prevent the hook from sliding such that the further angular movement of the drive member in the second direction causes the hook to pivot to the first position in which the first surface is in abutment with the protuberance, the second surface is free from abutment with the protuberance, the first edge is in abutment with the lock body assembly and the second edge is free from abutment with the lock body assembly. S

3. A lock as claimed in claim 2, wherein the lock body assembly includes .o.o top and bottom surfaces and the first and second edges alternately abut the top and bottom surfaces respectively.

4. The lock as claimed in any one of the preceding claims, wherein the lock body assembly includes a carriage which defines a bolt. S.

5. A lock as claimed in claim 4, wherein the carriage is slidably mounted S" in the lock body assembly and the hook is pivotally mounted to the carriage.

6. A lock as claimed in -any one of the preceding claims, wherein the hook is biased to the first and third positions by an over centre spring between the drive member and the lock body.

7. A lock as claimed in any one of the claims 4 to 7, wherein the bolt has a cross section with major and minor axes and the direction of travel of the hook between the first and second positions is substantially parallel to the major axis of the bolt.

8. A lock as claimed in any one of the claims 4 to 8, further including a face plate for mounting to an edge of the door and a pull tab including an opening for passage of the bolt therethrough, wherein the pull tab is pivotally mounted to the face plate at one end for pivoting between a first position substantially flush with the door [I :\DayLib\LIBD]00932.doc:AVS 12 edge and a second position angled with respect to the door edge to facilitate manual gripping of its other end.

9. A lock substantially as hereinibefore described with reference to the accompanying drawings. Dated 31 May 2005 Gainsborough Hardware Industries Limited Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [I \DayLib\LIBD]00932.doc:A VS