GB2215391A

GB2215391A - Closure mechanism

Info

Publication number: GB2215391A
Application number: GB8902328A
Authority: GB
Inventors: John Williams
Original assignee: WEST ALLOY DIECASTINGS
Current assignee: WEST ALLOY DIECASTINGS
Priority date: 1988-02-04
Filing date: 1989-02-02
Publication date: 1989-09-20
Anticipated expiration: 2009-02-02
Also published as: GB8802495D0; GB2215391B; GB8902328D0

Abstract

A sliding bolt type closure mechanism suitable for the door of a toilet or like compartment has a locking member (5) which when in situ in a door extends between opposite faces of the door and is operable from within the compartment to lock an external handle (2). In an emergency the locking member (5) may be operated externally of the compartment to move it from a locked position to a released position in which it allows rotation of the external handle (2) for withdrawal of the slide bolt (4) from a door frame keeper (10). Preferably the mechanism is provided with an internal handle (4g) arranged such that movement thereof to withdraw the slide bolt results in the locking member (5) automatically moving under the action of a spring (7) to adopt a released position. <IMAGE>

Description

"CLOSURE MECHANISM' This invention relates to a closure mechanism such as a latch or lock for a door and in particular, although not exclusively, to a mechanism such as a slide bolt type latch of the kind having the facility for the occupier of a toilet cabin, bathroom, or similar compartment, to prevent entry into the cabin by locking the outside handle from inside the cabin and thereby effectively preventing operation of the outside handle to withdraw the slide bolt.

In closure mechanisms of the aforedescribed kind it is desirable that in an emergency entry can be gained by operation of the outside handle.

The facility is particularly useful in a hospital or kindergarten where patients, invalids or young children are likely to require assistance.

In accordance with one of its aspects the present invention seeks tc provide a closure mechanism for a door which may be secured in a locked condition from a first side of the door but which in an emergency may be set to a released condition by action at a second side of the door.

The present invention provides, in accordance with one of its aspects, a closure mechanism for a door comprising: a body portion adapted for securing to a door, a closure member selectively movable relative to the body portion for extending from the body portion into engagement with a retention member associated with a door frame and for retracting back to the body portion;; a first actuating member operable from a first side of a door for movement of the closure member, a second actuating member operable from a second side of a door for movement of the closure member, and a locking member operable from a first side of a door for movement to a locked position in which it inhibits movement of the closure member by the second actuating member and for movement to a released position in which it allows movement of the closure member by the second actuating member, said locking member being adapted for operation from a second side of a door to move from said locked position to said released position and thereby allow movement of the closure member by the second actuating member.

Preferably the locking member is arranged to co-operate with the closure member whereby when the locking member is in said locked position operation of the first actuating member to retract the closure member permits the locking member to adopt said released position thereby to permit subsequent movement of the closure member by the second actuating member.

The locking member may be provided with a first abutment surface for co-operating with a second abutment surface provided by the closure member or the first actuating member to retain the locking member in the locked position until the first actuating member is operated to retract the closure member. The first and second abutment surfaces preferably each lie in planes which extend substantially transversely relative to the normal direction of movement of the locking member between its locked and released positions. The first abutment surface may be defined by a side wall of a groove, eg a rectangular cross-section groove, formed in the locking member and extending around at least a part of the outer surface of the locking member.The second abutment surface may be defined by a protrusion associated with the closure member or first actuating member and which is shaped to move into the groove whereby the second abutment surface may confront the first abutment surface. Preferably at least one of the first and second abutment surfaces is angled slightly relative to a plane transverse relative to said direction of relative movement and or at least one of the surfaces is a surface of a material sufficiently compliant to result in the two abutment surfaces separating transversely to release the locking member for movement from the locked position to a released position when a sufficient external load is applied to the locking member.

The locking member may comprise a frusto-conical shaped third abutment surface to facilitate ease of movement of the locking member relative to the closure member or first actuating member when being displaced from the released to the locked position. Alternatively the third abutment surface may be of a kind which extends substantially transversely relative to said normal direction of movement of the locking member for co-operation with a fourth abutment surface in substantially the same as one of the above described manners in which the first and second abutment surfaces may be arranged to be transversely displaceable when the locking member is externally loaded.

Locking member biassing means, which may be comprised by a mechanical spring, may be provided normally to urge the locking member to a released condition.

The locking member biassing means preferably is arranged to provided a force which acts in the same direction as but is less than that force which needs to be applied in said normal direction of movement of the locking member to displace the locking member from a locked to a released position.

Preferably at least one of the locking member and the closure member or first actuating member with which the locking member co-operates to adopt a locked position is formed from a plastics material which may be a moulded plastics material.

The closure mechanism may comprise also closure mechanism biassing means, which may comprise a mechanical spring, provided normally to urge the closure member to extend in a direction away from the body position.

The closure mechanism may be in the form of a slide bolt and the first actuating member may be comprised by a finger or like bolt head portion slideably operable from a first side of a door. The closure member be integral with the first actuating member.

The second actuating member may be comprised by a handle rotatable from a second side of a door, and may be of a kind having associated therewith at least one abutment face which engages the closure member, whether directly or indirectly, via, for example, the first actuating member. The rotatable handle may have associated therewith a pair of abutment faces for contacting respective abutment faces of a slide bolt, said faces being arranged to cause retraction of the slide bolt towards the body position when the handle is turned in either of a clockwise or an anti-clockwise direction. The handle may be rotatably supported by the body portion.

The body portion may comprise a first part securable to or at a first face of a door and a second part securable to or at a second face of a door, the two parts being interconnectable directly with one another or securable relative to one another by intervening structure which may be that of a door. Preferably the first and second parts of a body portion have complementary shaped formations of a kind adapted to ensure alignment of the parts of the body portion when the closure mechanism is in an assembled condition. The locking member may be supported directly by said first part of the body portion and indirectly by said second part.

When the second actuating member is a rotatable handle, the locking member may be elongate and arranged to extend through said handle, preferably in alignment with the axis of rotation of the handle. It is further preferred that the handle comprise a recess portion in which an end portion of an elongate locking member is positioned and is accessible for depressing in an inwards, axial direction towards the closure member from said locked position to said released position. The locking member may comprise at least one radially outwardly extending member which extends through an axially extending slit formation in an axially inner portion of the handle, typically a portion for lying within the thickness of a door. A pair of said outwardly extending members may be comprised by a cross-member.The or each outwardly extending member may be arranged to engage with an axially extending guide associated with the body portion over a part of the extent of axial movement of the locking member. The or each outwardly extending member preferably is arranged to co-operate with the slit formation(s) of the handle to ensure that the handle and locking member are rotatable at least substantially in unison for all axial positions of the locking member whilst the cross-member preferably is arranged to engage with the body portion guide to restrain rotation of the handle relative to the body portion only when the locking member lies axially at said locked position and to permit relative rotation when the locking member lies axially at said released position.

In use of a closure mechanism as described and claimed herein and fitted to the door of an enclosure with the first actuating member operable from within the enclosure it is to be understood that to lock the outside handle, the occupier of the enclosure pushes the locking rod towards the door making the other end of the locking rod protrude further out from the other side of the door. Entry to the enclosure can be gained in an emergency however by pushing the locking rod back towards the door, so that it protrudes further out from the interior face of the door, effectively unlocking the outside handle and thus allowing the outside handle to be turned to pull back the slide bolt.

In normal use when the occupier of the cabin or room requires exit, by directly withdrawing the slide bolt, the outside handle is automatically released from the locked condition, with the locking rod being caused to return to the unlocked position by the induced force of a mechanical spring.

One embodiment of the present invention will be described, by way of example only, with reference to the accompanying diagrammatic drawings, wherein: Figure 1 is a view of the exterior assembly of a closure mechanism of the present invention as seen from a front elevation; Figure 2 is a side view of the closure mechanism secured to a door; Figure 3 is a view of the closure mechanism as seen from a rear elevation; Figure 4 shows a sectional view of the closure mechanism; Figure 5 is an end view of the closure mechanism; Figures 6 and 7 show diagrammatic arrangements of the locking rod in relation to the slide bolt; Figure 8 shows an internal sectional view taken in the direction of arrow X of Figure 4 of a part of the closure mechanism;; Figures 9 and 10 are perspective views (part in section) of parts of the closure mechanism shown respectively in a locked and in a released position, and Figure 11 is a perspective view (part in section) of other parts of the closure mechanism.

A slide bolt type door latch in accordance with the present invention is shown in situ in a door, in the cross-sectional views of Figures 2 and 4. The door latch is formed substantially wholly of moulded plastics material and has a body portion comprised by an exterior case 1 and an interior case 3.

An external actuating means comprised by a handle 2 is retained relative to the exterior case 1 for rotation relative thereto, by a locking ring or circlip 6 located around a spigot 2a which forms an inner part of the handle. A hole 2b is provided through the centre of the handle 2 and an axially slideable locking rod 5 extends therethrough.

The head portion 2c of the handle 2 is provided with a well 2d of sufficient diameter and depth to allow a thumb to enter. The spigot end 2a of the handle 2 is provided with a recessed hole 2e in which a compression spring 7 is housed.

The wall portion of the handle surrounding the recessed hole 2e has a pair of slots 2f which extend along almost the whole of the axial length of the hole 2e.

The locking rod 5 comprises a locking rod cross member Se the ends of which engage with the respective slots 2f whereby the locking rod 5 is restricted against rotating relative to the handle 2 but is allowed to move axially relative to the handle. The wall on one side of the slot 2f is higher, ie axially longer, than the opposite side, and this higher arc shaped wall enters the interior case 3 when in situ with the corners 2g and 2h, making contact with faces 4a and 4b respectively on a first actuating means comprised by a slide bolt 4 housed in the interior case 3.

This wall also acts as a bearing surface for the locking rod cross member 5e. The shorter wall is also arc shaped but remains outside the interior case 3 and serves as an additional bearing surface for the locking rod cross member 5e so that when handle 2 is turned, the locking rod 5 turns with it.

A mechanical compression spring 7 is located in the hole 2e, with a stem portion of the locking rod 5 passing through the centre of the spring. The locking rod cross member 5e is positioned at one end of the spring and arranged such that the spring can act to move the locking rod 5 axially relative to the handle 2.

locking of the exterior handle 2 is achieved by pushing the locking rod 5 from the interior side towards the door, causing the two ends 5g and 5h of the locking rod cross member 5e to enter channels la and ib of the exterior case 1 so that the locking rod 5 cannot rotate relative to the exterior case. Because the exterior handle 2 and locking rod 5 cannot rotate relative to each other rotary movement of the exterior handle 2 relative to the exterior case 1 is prevented.

The slide bolt 4 is housed in the interior case 3 and is maintained normally in a forward position as shown in figure 4 by the induced force of two compression springs 8, with the nose 4c of the slide bolt protruding through an aperture 3a in the case 3. Location stability of these springs is achieved by the provision of two stabilising pegs 9 which pass through the spring centres. (In an alternative construction only one spring and one peg may be provided).

The insertion of the stem of the locking rod S in a direction towards the exterior case 1 causes the slide bolt 4 to move slightly inwards towards the back of interior case 3 causing further slight compression to the precomnpressed springs 8, so that the protrusion 4d on the latch slide rubs against the locking rod stem diameter 5f locating itself in recess 5a in the unlocked condition or recess Sc in the locked condition for thin doors, or alternatively recesses 5b and 5d respectively for thicker doors.

This sliding movement from the recess 5a, 5b to the rod stem diameter 5f is assisted by providing the rod stem with a frusto-conical shape bearing surface (not shown) therebetween. When the latch slide 4 is moved in further towards the back of the interior case 3, the protrusion 4d moves away from the rod stem diameter 5f, so that if the assembly is set in the locked condition, with the protrusion 4d located in recess Sc or alternatively 5d, the locking rod 5 will move towards the inside by virtue of the axial force inserted on it by the compression spring 7 housed in the exterior assembly, until recess 5a or alternatively recess 5b lines up with protrusion 4d which will then be in the unlocked position.

On closing the door from inside a cabin by pulling the interior case ridge 3b towards the cabin, the face 4e of the slide bolt slides against the corner edge 10a of the keep plate (see Figure 4), causing the slide bolt 4 to move into the interior case aperture 3a until the door is completely home. The slide bolt 4 is then pushed outwardly by the induced force imparted by compression springs 8 so that the slide bolt nose 4c rides over the keep plate until the underface 4f of the slide bolt is adjacent to the face lOb of the keep plate. On completion of this movement the locking rod 5 is pushed towards the door into the locking position. To open the door from the cabin side, the latch slide finger 4g is moved away from the keep plate 10. This action automatically unlocks the exterior handle 2, so that when the door is again closed it can be opened from the outside by turning handle 2, which in turn pulls the slide bolt 4 away from the keep plate 10.

Should access from the outside be required when the latch is in the locked position, the locking rod can be pushed from outside the cabin towards the door. This movement is assisted by compression spring 7.

The resulting force at the confronting surfaces of the protrusion 4d and recess Sc or 5d acts in combination with the compliability of the moulded plastics material defining these surfaces to displace the protrusion sideways out of the recess Sc or 5d and permit movement of the locking rod to a released condition. Thus, this action will unlock exterior handle 2, so that it can be rotated, which in turn withdraws the slide bolt 4 from keep plate 10.

It will be understood therefore that this invention provides for example a toilet or bathroom sliding bolt type of latch or like mechanism, having an inbuilt facility for enabling emergency access to a cabin room or compartment. This is accomplished by the provision of a locking rod 5 that can be pressed for locking from inside the cabin and pressed for unlocking from outside the cabin.

Claims

1. Closure mechanism for a door comprising: a body portion adapted for securing to a door, a closure member selectively movable relative to the body portion for extending from the body portion into engagement with a retention member associated with a door frame and for retracting back to the body portion, a first actuating member operable from a first side a door for movement of the closure member, a second actuating member operable from a second side of a door for movement of the closure member, and a locking member operable from a first side of a door for movement to a locked position in which it inhibits movement of the closure member by the second actuating member and for movement to a released position in which it allows movement of the closure member by the second actuating member, said locking member being adapted for operation from a second side of a door to move from said locked position to said released position and thereby allow movement of the closure member by the second actuating member.

2. A closure mechanism according to claim 1 wherein the locking member is arranged to co-operate with the closure member whereby when the locking member is in said locked position operation of the first actuating member to retract the closure member permits the locking member to adopt said released position thereby to permit subsequent movement of the closure member by the second actuating member.

3. A closure mechanism according to claim 2 and comprising locking member biassing means arranged normally to urge the locking member to a released condition.

4. A closure mechanism according to claim 3 wherein said locking member biassing means comprises a mechanical spring.

5. A closure mechanism according to any one of the preceding claims wherein the locking member is provided with a first abutment surface for co-operating with a second abutment surface provided by the closure member or the first actuating member normally to retain the locking member in said locked position.

6. A closure mechanism according to claim 5 wherein said first abutment surface is defined by a side wall of a groove formed in the locking member.

7. A closure mechanism according to claim 5 or claim 6 wherein said first and second abutment surfaces each lie in planes which extend substantially transversely relative to the normal direction of movement of the locking member between its locked and released positions.

8. A closure mechanism according to any one of the preceding claims wherein at least one of the locking member and the closure member or first actuating member is formed from a plastics material.

9. A closure mechanism according to any one of the preceding claims and comprising closure member biassing means arranged normally to urge the closure member to extend in a direction away from the body portion.

10. A closure mechanism according to claim 9 wherein said closure member biassing means comprises a mechanical spring.

11. A closure mechanism according to any one of the preceding claims wherein the closure member comprises a slide bolt and the first actuating member comprises a finger or like bolt head portion slideably operable from a first side of a door.

12. A closure mechanism according to any one of the preceding claims wherein the closure member is integral with the first actuating member.

13. A closure mechanism according to any one of the preceding claims wherein the second actuating member comprises a handle rotatable from a second side of a door.

14. A closure mechanism according to any one of the preceding claims wherein the second actuating member comprises at least one abutment face for engaging the closure member or first actuating member whereby movement of the second actuating member causes retracting movement of the closure member.

15. A closure mechanism according to claim 14 when dependent on claim 13 wherein the rotatable handle has associated therewith a pair of abutment faces for contacting respective abutment faces of a slide bolt and is arranged to cause retracting movement of the slide bolt when the handle is turned in either a clockwise or anti-clockwise direction.

16. A closure mechanism according to claim 13 or 15 wherein the handle is rotatably supported by the body portion.

17. A closure mechanism according to any one of the preceding claims wherein the body portion comprises a first part securable to or at a first face of a door and a second part securable to or at a second face of a door.

18. A closure mechanism according to claim 17 wherein said first and second parts are interconnected directly with one another.

19. A closure mechanism according to claim 17 wherein said first and second parts are adapted for securing relative to one another by intervening structure.

20. A closure mechanism according to any one of claims 17 to 19 wherein said first and second parts have complementary shaped formations adapted to ensure alignment of the parts of the body portion.

21. A closure mechanism according to claim 13 or any one of claims 14 to 20 when dependent on claim 13 wherein the locking member is arranged to extend through said handle.

22. A closure mechanism according to claim 21 wherein the locking member is an elongate member and is arranged to extend along the axis of rotation of the handle.

23. A closure mechanism according to claim 22 wherein the handle comprises a recess portion in which an end portion of the locking member is positioned.

24. A closure mechanism according to claim 22 or claim 23 wherein the locking member comprises at least one radially outwardly extending member which extends through an axially extending slit formation in an axially inner portion of the handle.

25. A closure mechanism according to claim 24 wherein the radially outwardly extending member engages with an axially extending guide associated with the body portion when the locking member moves over a part of the extent of its range of axial movement relative to the locking member.

26. A closure mechanism according to claim 24 or claim 25 wherein the radially outwardly extending member co-operates with the slit formation of the handle to ensure that the handle and locking member are rotatable at least substantially in unison for all axial positions of the locking member relative to the handle.

27. A closure mechanism according to claim 26 wherein the radially outwardly extending member is arranged to engage with the axially extending guide of the body portion only when the locking member lies at an axially outwards position in which it is displaced away from the closure member to lie in said locked position.

28. A closure mechanism constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

29. A door assembly comprising a door and a closure mechanism according to any one of the preceding claims wherein the closure mechanism is secured to the door with the locking member extending through the door and accessible at both sides of the door.