AU773718B2 - A privacy adaptor - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT 0 00 .00.

0 0 0 0 0 0 o.

Name of Applicant: Actual Inventor: Address for Service: Invention Title: LOCKWOOD SECURITY PRODUCTS PTY

LIMITED

Christopher Stephen KORVIN CULLEN CO., Patent Trade Mark Attorneys, 239 George Street, Brisbane, QId. 4000, Australia.

A PRIVACY ADAPTOR Details of Associated Provisional Applications: No. PQ4485 filed 27 October 1999 The following statement is a full description of this invention, including the best method of performing it known to us A PRIVACY ADAPTOR FIELD OF THE INVENTION This invention relates to a privacy adaptor which can form part of a door latch attached to a door.

BACKGROUND ART Privacy adaptors are known and comprise parts which can be o10 fitted to a variety of different types of latch sets to provide a privacy locking function which finds particular use for a bathroom door and a toilet door.

The privacy adaptor allows the door to be locked from the inside to provide a degree of privacy. However, in conventional adaptors, a key is not required and instead the door is locked by a lever, push button, or other type of snibbing mechanism.

It is desirable to ensure that the door can be opened from the outside in case of an emergency.

Privacy adaptor sets are known which have a part which extends through the latch set and is manipulable from the outside of the door.

20 This can be in the form of a button having a groove which can be turned :'.."using a screwdriver or the edge of a coin to allow the door to be opened from the outside in case of an emergency.

It is known to provide a snib on the outside of the door which can be operated to open the door in an emergency situation.

A disadvantage with this type of privacy set, is that there is little difficulty in opening the door from the outside. Thus, any person wishing to open the door for reasons other than a genuine emergency can do so, which can cause embarrassment to the occupant. The degree of genuine "privacy" is therefore low.

A privacy adaptor is known which does not have an easily accessible outer snib, etc. This adaptor requires removal of part of the outside door knob to operate the door from the outside. This would be a distinct disadvantage in a genuine panic emergency.

Other known privacy adaptor sets suffer from various disadvantages including complexity of manufacture, the need for small parts which are susceptible to breakage, the requirement for rocker arms to form part of the snib, and the requirement for the adaptor sets to have components which extend through to the outside part of the door latch (and thereby allowing the door to be opened in an emergency situation).

Thus, there does not appear to be a privacy adaptor which does not have a too easily accessed outer snib etc, but which does not require 10 dismantling of the knob to operate the door from the outside. There does also not appear to be a privacy adaptor which has a simpler and reliable design.

OBJECT OF THE INVENTION The present invention is directed to a privacy adaptor for a door latch which may overcome at least some of the abovementioned disadvantages or provide the public with a useful or commercial choice.

In the present invention, a simple yet reliable mechanism has *"been developed which uses a single reciprocatable locking bar which can be fitted to the door latch to lock or unlock the latch and which does away with 20 the need for snib mechanism which comprise levers, rotatable members and :the like.

One form of the invention also includes an emergency access arrangement where instead of requiring a screwdriver or the like to open the door from the outside, the door knob can be forced to disengage the locking bar in a non-destructive manner. This arrangement does away with the need for more complicated parts which extend entirely through the door latch to be accessible from the outside of the door.

In one form, the invention comprises a privacy adaptor for a door latch, the door latch having a spindle and a latch bolt, the adaptor having a rotor attachable to the spindle for rotation with the spindle, a locking member which is manually operable between a first position where the locking member and the rotor are locked to each other such that the rotor is prevented from rotation upon normal operation of the door latch, and a second position where the rotor is able to rotate, and override means which, when the rotor and locking member are locked together, will force the rotor and locking member to become freed in a non destructive manner, when the door latch is forced in excess of its normal operation In another form, the invention resides in a privacy adaptor for a door latch, the adaptor having a locking bar which is able to be manually slidably moved between a locked position where the latch bolt cannot be retracted, and a free position where the latch bolt can be retracted, the 10 locking bar having a portion which can be accessed by a persons fingers to :move the bar between its locked and free position.

In a more particular form, the invention resides in the adaptor :further comprising a rotor which is attached to a spindle to rotate with the spindle, the spindle being operatively associated with the latch bolt to move the latch bolt upon rotation of the spindle, the rotor and the locking bar being biased together by a biasing means, the rotor and locking bar being locked together when the locking bar is in the locked position, thereby preventing rotation of the spindle, the rotor being able to rotate with the spindle when the locking bar is in the free position, the rotor and locking bar, when in the locked 20 position being able to be forced apart in a non-destructive manner upon forcing the door handle of the door latch, thereby allowing the latch bolt to be retracted in an emergency situation.

The privacy adaptor may include a locking bar which can be moved by a person's fingers and is movable in a sliding or reciprocating manner in the door latch. For instance, the locking bar can be simply pushed up or pushed down (if the locking bar in a vertical orientation) or pushed from side to side (if the locking bar is in a horizontal orientation). Therefore, by simply pushing the locking bar, the door latch can be locked or unlocked to provide a degree of privacy.

In the more particularised form of the invention, the locking bar is biased against a rotor, and the rotor is attached to the door spindle to rotate with the spindle. This is typically achieved by making the spindle of a square cross-section and providing a square bore in the centre of the rotor such that the rotor can turn with the spindle. In the locking bar (in the locked position), it is locked to the rotor and therefore the rotor cannot rotate which means that the spindle cannot rotate which means that the latch bolt cannot be retracted.

When the locking bar can be pushed to a free position where the rotor can now rotate relative to the locking bar which means that the latch bolt can be retracted or extended.

In a panic or emergency situation, when the locking bar is locked to the rotor, the door handle or knob can be forcibly turned to cause 10 the two components to separate in a non-destructive manner thereby allowing the door to be opened.

The adaptor can be fitted to a variety of different types of door latches.

The locking bar may comprise an elongate planar member. The S. 15 elongate planar member may have an aperture extending therethrough through which the latch spindle can pass but where the latch spindle does not engage with the locking bar to cause the locking bar to rotate. This can be achieved by ensuring that the aperture is larger than the cross-section size of the spindle. The aperture may be oval or elongate to allow the locking bar to 20 slide between its locked and free positions without contacting or being operated by the spindle. It is envisaged that the locking bar may have a configuration that does not require any aperture through which the spindle passes and indeed the locking bar may be curved or otherwise profiled to extend past the spindle without being operated by the spindle.

The locking bar is held for reciprocating movement.within the door latch. It is also preferred that the locking bar is held against any rotative movement such that the only motion available to the locking bar is a reciprocating motion.

The privacy adaptor may have a main body portion which can sit under an existing knob or lever handle rose. The main body portion may have an internal configuration to guide the locking bar for sliding movement but to prevent the locking bar from rotating.

The locking bar has a portion which can be accessed by a person's fingers, and this may be in the form of a T-shaped button or portion which extends from the main body portion and which can be pulled and/or pushed by a person's fingers. The main body portion may be provided with slots or cut-outs through which the T-shaped button may extend.

The privacy adaptor suitably includes a rotor which is attached to the latch spindle in such a manner that it will rotate with the spindle. This is typically achieved by having the spindle in the form of an elongate square bar and providing the rotor with a central square aperture through which the e: l0 spindle can pass. The rotor may be disc-shaped and can sit within the main body portion. The rotor may be positioned adjacent the locking bar and may have a first face which faces the locking bar and a second opposite face which faces away from the locking bar.

The locking bar and the rotor may be biased together by biasing means. The biasing means may be in the form of one or more spring washers which can be positioned between the main body portion and the second face of the rotor to bias the first face of the rotor against the locking 6 *0 bar. Of course, other types of biasing means could be used including helical springs, leaf springs, resilient elastomer members and the like.

The rotor and the locking bar may be provided with engagement means to lock the two components together when the locking bar is in the locked position. The engagement means may be in the form of one or more projections on one of the components which engage in one or more complimentary recesses on the other of the components but only when the locking bar is in the locked position. When the locking bar is moved to the free position, the engagement means preferably do not substantially engage each other.

In an embodiment, the locking bar can be provided with a pair of spaced apart lugs or dogs which engage with corresponding grooves in the first face of the rotor, the dogs and the grooves being arranged such that they engage when the locking bar is in the locked position but disengaged when the locking bar is in a free position.

In one form of the invention, a means is provided to override the locking action between the locking bar and the rotor in an emergency situation. This can be achieved by having the engagement means arranged in such a manner that the two components lock against each other to prevent the spindle from being rotated when the door knob or handle is rotated using a normal amount of force, but when excessive force is used, the locking bar can be forcefully separated from the rotor thereby allowing the door latch to be opened.

In one form, this can be achieved by providing the grooves with gO .o o i divergent side walls (to approximate a V-shape) which allows the dogs on the locking bar to be forced out of the groove upon forcibly turning the door knob handle.

The "strength" of the biasing means may also be varied to vary the force required to open the door in an emergency situation.

BRIEF DESCRIPTION OF THE DRAWINGS o embodiment of the invention will be described with reference to the following drawings in which Figure 1 shows an exploded view of a privacy adaptor from a 20 front angle.

S"Figure 2 shows the exploded view of the privacy adaptor from a rear angle.

BEST MODE Referring to the drawings, there is illustrated parts for a privacy adaptor for a door latch, the parts being a main body portion 10, a number of spring washers 11 which form a biasing means, a rotor 12, a locking bar 13 and a retaining plate 14.

Briefly, the privacy adaptor can be assembled to a door latch to convert the door latch into a privacy set which allows the door latch to be locked from one side of the door.

The remainder of the door latch is not illustrated but typically comprises a knob or lever handle on each side of the door. Below the knob or lever handle is a furniture rose which is a decorative metal or plastic shroud to cover the various components. The knob or handle on each side of the door are attached together via a spindle which is typically a steel bar having a square cross-section or can comprise a steel strip. The door handles have a slot or socket to accommodate the ends of the spindle which means that when one handle is rotated, the spindle rotates to cause rotation of the other handle. This arrangement is extremely well-known. The spindle operates the latch bolt of the door latch by retracting the latch bolt or lo extending the latch bolt upon rotation of the spindle. Again, this arrangement is itself extremely well-known.

In the embodiment, the spindle can be locked against rotation and therefore against retraction of the latch bolt by the locking bar 13 which works by being slidable between a locked position and an unlocked position 15 and able to be slid between the two positions by a person's fingers.

Locking bar 13 has a plate-like main body portion 15 which has a large oval shaped central aperture 16 through which the spindle (not illustrated) passes. In fact, it can be seen in Figures 1 and 2 that all the illustrated components have central apertures and the spindle passes through 20 the aperture in the main body portion 10, the spring washers 11, the rotor 12, S'*locking bar 13, and retaining plate 14. Aperture 16 in locking bar 13 is oval and large and is much larger than the cross-section size of the spindle which means that when the spindle rotates, the spindle does not cause rotation of locking bar 13. As well, the apertures in the spring washers 11, the main body portion 10 and the retaining plate 14 are such that these components do also not rotate with rotation of the spindle.

Rotor 12 on the other hand, has a square-shaped aperture 17 which means that it will be locked to the spindle in such a manner that it must rotate with rotation of the spindle. A square shaped aperture in a rotor is wellknown.

Main body portion 10 (see Figure 2) is substantially hollow and is provided with two diametrically opposed cut-outs or slots 18. Locking bar 13 has a pair of opposed T-shaped buttons 19 and the stem of each Tshaped button 19 extends through cut-outs 18. The top rounded portion of each button overlies the respective cut-outs. Main body portion 10 slidably houses locking bar 13 to allow the locking bar to slide between a first position where one of the T-shaped buttons projects from cut-out 18 while the other Tshaped button is more or less against cut-out 18, and this can be reversed by pushing the locking bar the other way.

The three spring washers 11 sit within a central cavity in main body portion 10 and are supported by the spindle. Rotor 12 abuts against 1o one of the spring washers and the function of the spring washers is to bias rotor 12 against locking bar 13.

Rotor 12 has a first face 20 which faces locking bar 13, and a second face 21 which faces the spring washers 11.

Figure 2 better illustrates that the first face 20 of rotor 12 is provided with an extending annular ridge or collar 22 which has two diametrically opposed V-shaped grooves 23 (only one groove illustrated in ***Figure 1 but both illustrated in Figure The grooves are deliberately Vshaped and therefore have outwardly diverging side walls the reason for which will be described in greater detail below.

20 Locking bar 13 is provided with a pair of lugs or dogs 24 (illustrated only in Figure Dogs 24 are positioned on the main body portion of locking bar 13 in such a way that they engage into the V-shaped grooves 23 on rotor 12 but only when the locking bar has been pushed to one of its positions (the locking position), but when the locking bar is pushed to the other position (the free position), dogs 24 do not sit within grooves 23.

Thus, when the locking bar 13 is pushed to its locking position such that dogs 24 are within grooves 23, rotor 12 is locked against rotation.

Locking bar 13 cannot rotate as it is held by main body portion 10 and possibly also by the retaining plate 14. Thus, when the dogs are engaged in the grooves, rotor 12 cannot rotate which means that the spindle cannot rotate which means that the door knobs cannot rotate and thus the latch bolt cannot be retracted.

To unlock the door latch, the locking plate 13 is manually pushed to its other position to disengage the dogs 24 with grooves 23 which means that the rotor can now freely rotate and the spindle can now be turned to retract the latch bolt.

The design of grooves 23 and the choice of the spring washers 11 is such that the privacy adaptor has an emergency override arrangement.

When the adaptor is in the locked position where dogs 24 are within grooves 23, the door knobs cannot be turned when a usual amount of force is applied.

However, in an emergency situation, the door handles can be lo turned with much greater force and this will cause rotor 12 to exhibit a large degree of torque against locking bar 13. This in turn causes the dogs 24 to ride up against one of the diverging side walls of the groove (the wall depending on which way the rotor is being turned) and the rotor will progressively be pushed back against the bias of spring washers 11. At S 15 some stage, the dogs 24 will have ridden out of the grooves 23 which will now free the rotor to allow the door to be opened. It is important to note that this .*.arrangement is non-destructive which means that the privacy adaptor components are not damaged and the door latch can be reused.

The arrangement is simple yet robust and allows a locked door 20 to be opened from the outside in an emergency situation without requiring S0complicated components which extend to the outside of the door and which can be manipulated by a screwdriver, coin edge and the like.

It should be appreciated that various other changes or modifications may be made to the embodiment described without departing from the spirit and scope of the invention as claimed.

Claims (24)

1. A privacy adaptor for a door latch, the door latch having a spindle and a latch bolt, the adaptor having a rotor attachable to the spindle for rotation with the spindle, a locking member which is manually operable between a first position where the locking member and the rotor are locked to each other such that the rotor is prevented from rotation upon normal operation of the door latch, and a second position where the rotor is able to rotate, and override means which, when the rotor and locking member are locked together, will force the rotor and locking member to become freed in a non destructive manner, when the door latch is forced in excess of its normal operation.

2. The adaptor of claim 1, wherein the locking member is a locking bar.

3. The adaptor of claim 1 or claim 2, comprising a rotor which is attachable to a spindle to rotate with the spindle, the spindle being 20 operatively associated with the latch bolt to move the latch bolt :upon rotation of the spindle, the rotor and the locking bar being :biased together by a biasing means, the rotor and locking bar being locked together when the locking bar is in the locked position, thereby preventing rotation of the spindle, the rotor being able to rotate with the spindle when the locking bar is in the free position, the rotor and locking bar, when in the locked position being able to be forced apart in a non-destructive manner upon forcing the door S:handle of the door latch, thereby allowing the latch bolt to be retracted in an emergency situation.

4. The adaptor of any one of the preceding claims, wherein the spindle has a square cross-section and the rotor has a square bore in the centre of the rotor such that the rotor can turn with the spindle.

The adaptor of any one of the preceding claims, wherein the locking bar comprises an elongate planar member.

6. The adaptor of claim 5, wherein the locking bar has an aperture extending therethrough through which the latch spindle can pass but where the latch spindle does not engage with the locking bar to cause the locking bar to rotate.

7. The adaptor of any one of the preceding claims, wherein the locking bar is held for reciprocating movement within the door latch.

8. The adaptor of any one of the preceding claims, wherein the privacy adaptor has a main body portion which can sit under an existing knob or lever handle rose.

9. The adaptor of claim 8, wherein the main body portion has an internal configuration to guide the locking bar for sliding movement but to prevent the locking bar from rotating.

10. The adaptor of any one of the preceding claims, wherein the locking bar has a portion which can be accessed by a person's fingers.

11. The adaptor of claim 10, wherein the portion is in the form of a T- shaped button or portion which extends from the main body portion and which can be pulled and/or pushed by a person's fingers. 0 t

12. The adaptor of claim 11, wherein the main body portion is provided with slots or cut-outs through which the T-shaped button may extend.

13. The adaptor of any one of the preceding claims, wherein the rotor is positioned adjacent the locking bar and has a first face which 13 faces the locking bar and a second opposite face which faces away from the locking bar.

14. The adaptor of any one of the preceding claims, wherein the locking bar and the rotor are biased together by biasing means.

The adaptor of claim 14, wherein the biasing means comprises one or more spring washers which are positioned between the main body portion and the second face of the rotor to bias the first face of the rotor against the locking bar.

16. The adaptor of any one of the preceding claims, wherein the rotor and the locking bar are provided with engagement means to lock the two components together when the locking bar is in the locked position.

17. The adaptor of claim 16, wherein the engagement means is in the form of one or more projections on one of the components which :engage in one or more complimentary recesses on the other of the 20 components but only when the locking bar is in the locked position. 0 0

18. The adaptor of claim 17, wherein when the locking bar is moved to i the free position, the engagement means do not substantially engage each other.

19. The adaptor of any one of the preceding claims, wherein the locking bar is provided with a pair of spaced apart lugs or dogs which engage with corresponding grooves in the first face of the rotor, the dogs and the grooves being arranged such that they S 30 engage when the locking bar is in the locked position but disengaged when the locking bar is in a free position.

The adaptor of claim 19, wherein the grooves have divergent side walls (to approximate a V-shape) which allows the dogs on the 14 locking bar to be forced out of the groove upon forcibly turning the door knob or handle.

21. The adaptor according to any one of the preceding claims, wherein the adaptor has a locking bar which is able to be manually slidably moved between a locked position where the latch bolt cannot be retracted, and a free position where the latch bolt can be retracted, the locking bar having a portion which can be accessed by a persons fingers to move the bar between its locked and free position.

22. A door latch assembly comprising the adaptor as claimed in any one of the preceding claims. S 15

23. A door knob or door handle assembly which comprises an inner door knob/handle and an outer door knob/handle, a spindle which interconnects the inner and outer door knobs/handles, a latch bolt which is operable by the spindle between a locking and unlocking *position, a locking member which is operable to hold the latch bolt in its locking position, and override means which overrides the locking member upon forced rotation of the outer door knob/handle. *fee

24. An adaptor substantially as hereinbefore described with reference to the accompanying drawings. DATED this 7 th day of April 2004 LOCKWOOD SECURITY PRODUCTS PTY LIMITED 086 451 907) By their Patent Attorneys CULLEN CO.