AU6672294A

AU6672294A - Lock mechanism

Info

Publication number: AU6672294A
Application number: AU66722/94A
Authority: AU
Inventors: Tuomo Toivonen
Original assignee: Black and Decker Inc
Current assignee: Black and Decker Inc
Priority date: 1993-05-03
Filing date: 1994-05-02
Publication date: 1994-11-21
Anticipated expiration: 2014-05-02
Also published as: AU673077B2

Description

LOCK MECHANISM

The present invention relates to improvements in latch and lock mechanisms and in particular to mortice type door locks capable of being operated by at least one external operating handle. Latch and lock mechanisms of the aforementioned kind are well known, however, it is desirable when the mechanism is in a locked condition that the operating handle be capable of rotation through at least a limited arc without providing any strain or force on the latching tongue to try to move same towards a withdrawn position. The present invention aims at providing an arrangement capable of achieving the foregoing performance requirements in a latch or lock mechanism, preferably by use of simple and reliable means.

Accordingly, the present invention provides a latching mechanism comprising a latching tongue adapted for movement between an extended latching position and a withdrawn delatched position, operation means adapted, in use, to be linked with and moved in response to movement of external actuating means, said operation means being selectably configurable in at least two different configurations whereby in a first one of said configurations, movement of said operation means effects movement of said latching tongue to said withdrawn delatched position and in a second one of said configurations, movement of said operation means does not effect movement of said latching tongue towards said delatched position.

In accordance with a further aspect, the present invention provides a latching mechanism comprising a latching tongue adapted for movement between an extended latching position and a withdrawn de-latched position, operation means adapted, in use, to be linked with an external operating member, said operation means interlinking the or each said external operating member with said latching tongue so as to enable movement of said latching tongue between said extended latching position and said withdrawn de-latched position upon movement of the or at least one said external operating member, said operation means comprising a first member adapted for movement with the said external operating member, a second member adapted to cooperate with said latching tongue to effect movement thereof and actuable means selectably operable between said first and second members whereby in one selected position, said first and second members move together upon movement of said external operating member and in at least a second selected position, said first member is movable separately to said second member whereby said second member does not effect movement of said latching tongue upon movement of said external operating member.

The present invention includes latching mechanisms or latching mechanisms including external operating members fixed with or releasably securable to the operation means of the latching mechanism. The present invention further includes latching mechanisms with or without a locking device. The locking device may be a key operated locking device or any other arrangement. Preferably the present invention is applicable to mortice type door locks but could be used in other lock or latching applications.

Preferably, the or each external operating member comprises a rotatable handle connected in conventional fashion by a non-circular (usually square) drive rod to the internal mechanism of the lock. The inner end of the drive rod conveniently engages within a non-circular (usually square) aperture in a handle operating plate forming the aforesaid first member. In this manner the handle operating plate rotates upon rotation of the external handle. Conveniently, a latching tongue operating clutch plate is provided forming the aforesaid second member located adjacent to the handle operating plate with a section cooperable with the latching tongue of the lock mechanism to move same upon rotation of the latching tongue operating clutch plate. Conveniently the actuable means comprises an axially extending projection on one of said handle operating plate or said latching tongue operating clutch plate selectably engageable or disengageable with a recess in the other of said plates so that said plates may be selectably rotated together or alternatively said handle operating plate can be rotated independently of said latching tongue operating clutch plate. Preferably one of the aforesaid plates includes a central boss fitting through a central aperture in the other of said plates, said aperture being longer in one direction permitting the two plates to be relatively moved in said one direction to selectably engage or disengage said axially extending projection from its cooperating recess. Advantageously, the aforesaid central boss is formed in the handle operating plate and is generally coaxial with the non-circular recess for receiving the handle drive rod or shaft. It will of course be appreciated that with a lock mechanism having two operating handles, an arrangement as above described may be provided associated with either external operating handle or both as may be desired.

One particularly preferred embodiment of the present invention is described hereinafter with reference to the accompanying drawings. The drawings illustrate schematically the principal of the present invention with parts omitted for the sake of clarity. It will of course also be appreciated that commonly known and used features of lock mechanisms of this kind may be readily incorporated in locks according to the present invention although these will not hereinafter be described as they will be well known to those skilled in this art. In the accompanying drawings :- Figure 1A is a plan view of a preferred form of lock mechanism according to the present invention;

Figure 1 B is a perspective view of Figure 1A with some parts omitted for the sake of clarity;

Figures 2A/2B, 3A/3B and 4A/4B are views similar to Figures 1A and 1 B showing different positions of the mechanism.

Referring now to the drawings, the lock mechanism 10 illustrated comprises a latching tongue member 11 having an outer tongue portion 12 and an inner end 13. The latching member 11 is normally urged outwardly by a spring member (not shown) so that, in use, the tongue portion 12 can engage with a latching plate in a door surround or the like. A door operating handle would, in use, be connected to the illustrated mechanism by a square drive bar or shaft engaging both with the handle and with the square drive recess 14 in the mechanism 10. The handle and drive shaft are not shown for the sake of clarity. The position of a key operated lock device 15 is shown in phantom outline with the inner end of the lock barrel carrying a plate with a laterally extending tab 16 such that the end of the tab may pass through the arc 17 upon rotation of the lock barrel. In this manner, the tab 16 may engage the inner end 13 of the latching member 11 to withdraw same into the lock housing (not shown) against action of the outwardly urging spring or alternatively, engage a respective one of inwardly directed projections 18,19 on a rear slideable locking bar 20 to thereby position the locking bar in one of two possible positions. The 5 locking bar 20 is restrained to slide in the direction indicated by arrow 21 and a detent mechanism 22 is engageable with a respective one of the recesses 23,24 in the end of the bar 20 so as to releaseably hold the bar 20 in one of the two possible positions. The detent mechanism 22 is stationary apart from inward and outward movement of the end engagement part 25 against or with 0 the urging force provided by spring 26 in the direction of arrow 27.

At the other end of the locking bar 20 a laterally extending part 28 engages with a mechanism 29 cooperably linking the handle drive recess 14 with the latching tongue member 11. The mechanism 29 comprises a latching tongue operating plate 30 parallel to and adjacent to a handle operating plate

1 5 31 with the latter plate 31 also having the square handle drive recess 14 formed therein. The latching tongue operating plate 30 has an extending projection 32 adapted to cooperate with the inner end 13 of the latching tongue 11 to withdraw same inwardly upon rotation of the plate 30 (as shown in Figures 1A/1 B). A recess 33 is formed in the end of the plate 30 opposite to the 20 projection 32, said recess 33 engaging with the laterally extending part 28 so that movement of the bar 20 results in movement of the latching tongue operating plate 30. As an alternative to the arrangement illustrated, it may be possible to arrange a laterally extending projection on the plate 30 engageable with a recess in the bar 20 rather than the reverse shown in the illustrated 5 preferred embodiment.

The latching tongue operating plate 30 is generally constrained to move in a direction parallel to movement of the bar 20 (i.e. arrow 21 ). The constraining means may conveniently comprise a plate member 36 (Figure 2A) engageable with the sides 34,35 of the plates 30,31 opposite the bar 20. The 30 plate member 36 is pivotable about a pivot point 37 adjacent the latching tongue member 11 with a spring 38 urging the plate member 36 in a direction so as to try to maintain the position shown in Figure 2A. This enables the mechanism 29 to pivot as shown in Figure 1A when required but otherwise ensures the plate 30 moves parallel to the direction of movement of the bar 20.

Further, the handle operating plate 31 includes a tab or projection 39 bent towards the latching tongue operating plate 30 to cooperate with a recess 40 formed therein. Depending on the position of the plate 30 (after movement via the interaction with the locking bar 20), the tab 39 is either engaged in the recess 40 (as shown in Figures 1A/1 B and 2A/2B) or is disengaged therefrom (as shown in Figures 3A/3B and 4A/4B). Thus, when the tab 39 is engaged with the recess 40, the plates 30,31 rotate together and when they are disengaged, the handle operating plate 31 will be rotatable separately from the plate 30. Finally, the plate 30 includes a central elongated recess 41 engaged over and slideable on a circular boss 42 forming part of the handle operating plate 31 , the boss 42 generally surrounding the square drive recess 14 formed therein. This arrangement permits the plates 30,31 to be relatively moved upon selective movement of the locking bar 20 while still allowing the plate 31 to rotate relative to the plate 30 as shown, for example, in Figures 3A/3B.

The arrangement shown in Figures 1A/1 B is an unlocked condition where the latch tongue member 11 is withdrawn by engagement of the projection 32 with the inner end 13 of the latch tongue member 11. The plates 30,31 are interengaged so as to rotate together upon rotation of the operating handle (not shown). Figures 2A/2B is also an unlocked condition similar to Figures 1A/1B except that the handle has not been rotated and the latch tongue member is extended to a latching (unlocked) position. In Figures 3A/3B and 4A/4B, the lock bar 20 has been moved to a second detent controlled position where the plates 30 and 31 are relatively moved to disengage the projection 39 from the recess 40 (as shown in Figures 4A/4B). In this condition, rotation of the handle and thereby the plate 31 does not cause rotation of the plate 30 and therefore the member 11 is not capable of being withdrawn.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A latching mechanism comprising a latching tongue adapted for movement between an extended latching position and a withdrawn delatched position, operation means adapted, in use, to be linked with and moved in response to movement of external actuating means, said operation means being selectably configurable in at least two different configurations whereby in a first one of said configurations, movement of said operation means effects movement of said latching tongue to said withdrawn delatched position and in a second one of said configurations, movement of said operation means does not effect movement of said latching tongue towards said delatched position.

2. A latching mechanism according to Claim 1 , wherein said operation means comprises a first member adapted for movement in response to movement of the external actuating member, a second member adapted to co¬ operate with the latching tongue to effect movement of said latching tongue and actuable means selectably operable between said first and second members whereby in said first configuration said actuable means is positioned to ensure said first and second members move together in response to movement of the external actuating means and in said second configuration said actuable means is positioned to ensure the first member is movable separately to said second member whereby said second member does not effect movement of said latching tongue in response to movement of the external actuating means.

3. A latching mechanism according to Claim 2, wherein said second member comprises a latching tongue operating clutch plate located adjacent an operating plate mounted for rotation in response to rotation of the external actuating means, said latching tongue operating plate being mounted for movement relative to said operating plate.

4. A latching mechanism according to Claim 3, wherein said latching tongue operating clutch plate is mounted for translational movement and rotational movement relative to said operating plate.

5. A latching mechanism according to Claim 4, wherein said operating plate includes a central boss and said latching tongue operating clutch plate includes an aperture configured to fit over said central boss, said aperture being longer in one direction permitting said plates to be relatively movable in said one direction.

6. A latching mechanism according to Claim 4, wherein said operating plate includes a central aperture and said latching tongue operating clutch plate includes a boss, said aperture being configured to fit over said boss, said aperture being larger in one direction permitting said plates to be relatively movable in said one direction.

7. A latching mechanism according to any one of Claims 4 to 6, wherein said actuable means comprises an axially extending projection on one of said operating plate or said latching tongue operating clutch plate selectably engageable or disengageable with a recess in the other of said plates so that said plates may be selectably rotated together or alternatively said operating plate is rotatable independently of said latching tongue operating clutch plate.

8. A lock mechanism including a latching mechanism according to any one of Claims 1 to 7 and further including a lock device to fix said latching tongue in said latching position.

9. A lock mechanism according to Claim 8, wherein said lock device also selectably positions said operation means in one of said two different configurations.

10. A lock mechanism according to Claim 9, wherein when said lock device fixes said latching tongue in said latching position, said lock device also arranges said operation means in said second configuration.

11. A lock mechanism according to any one of Claims 8 to 10, further including a link member linking said lock device with said operation means.