GB2498425A - Lock mechanism - Google Patents

Abstract

A lock mechanism 10, particularly for a sliding or patio door, having a driving member 26 and a driven member 36 which move in opposing directions with movement of the driving member is communicated to the driven member by drive componentry, the drive componentry including at least one substantially circular drive disc 58 which can rotate within a circular opening 54, and drive elements which interconnect the drive disc with the driving member and with the driven member. The drive elements are preferably drive pegs 66 which locate within drive slots 70 of the driving 26 and driven members 36. The drive disc may have two notches 60, each to accommodate a ball bearing 64 which is resiliently biased towards the notch to lock the disc in place. The lock is compact and thus suitable for sliding doors with thin or narrow frames.

Description

LOCK MECHANISM

FIELD OF THE INVENTION

This invention relates to a lock mechanism, and in particular to a lock mechanism for a sliding (patio) door or a folding/sliding door. The invention can also be used on windows and other moving panels, but the application will refer to "door" for brevity.

io Directional and orientational terms used in this specification, such as top", "bottom", etc., are used to describe the door and its components in their normal orientation of use.

BACKGROUND TO THE INVENTION

A traditional mortice lock utilises a bolt which can be driven to project from the locking edge of the door. Such locks are suitable for hinged doors where the path of movement of the bolt is substantially perpendicular to the opening movement of the door. They are not suitable for sliding doors such as patio doors for example, because the path of movement of the bolt is parallel to the opening movement of the door.

Accordingly, sliding doors use an alternative lock mechanism, for example an espagnolette mechanism, in which one or more locking bars are moved perpendicular to the locking edge (typically up and down), and perpendicular to the opening movement of the door. The or each locking bar typically carries a number of mushroom-headed bolts which can be located in respective keepers.

Since the path of movement of the mushroom-headed bolts is perpendicular to the path of movement of the door, the locking bar can lock the door in its closed position.

The espagnolette mechanism can also drive shoot bolts or the like into the top and/or bottom rail of the door frame, for additional security.

Many sliding doors, including most patio doors, have a glazed panel surrounded by a panel frame. The panel frame is in turn located within a mounting frame located in the wall opening. The mounting frame comprises a set of channel members within which the panel frame is movable between opened and closed positions of the door.

It is a feature of many sliding doors that the width of the panel frame (i.e. the io dimension parallel to the plane of the glass) is minimised so that the glazed area of the movable door is maximised. In particular, many sliding door manufacturers are seeking to provide sliding doors having the appearance of being substantially frameless, i.e. the panel frame is only slightly wider (if at all) than the depth of the channel of the surrounding channel members, so that the customer effectively is sees a complete movable glazing panel located within the fixed mounting frame.

Since the lock mechanism is typically fitted into the panel frame of the sliding door the desire to minimise the dimensions of the panel frame impacts upon the design of the lock mechanism. There is often a compromise between security (which typically requires a large and robust lock mechanism) and aesthetics (which typically requires a small and compact lock mechanism permitting the minimum dimensions for the panel frame).

SUMMARY OF THE INVENTION

The inventors have been faced with the task of providing a lock mechanism which can fit into the panel frame of a "substantially frameless" sliding door, i.e. a sliding door having a panel frame of very small width. The inventors have therefore sought to provide a lock mechanism of very small width without compromising the security which is provided. In particular, the inventors have sought to provide an espagnolette lock mechanism which can drive locking bars and/or shoot bolts in opposed directions.

According to the invention there is provided a lock mechanism for a sliding door having a driving member and a driven member, the driven member moving in the opposed direction to the driving member, movement of the driving member being communicated to the driven member by drive components, the drive components comprising a substantially circular drive disc which can rotate within a substantially circular opening, the drive disc carrying drive pegs which engage respective drive slots in the driving member and the driven member.

It is known for espagnolette mechanisms to drive shoot bolts in opposed directions, and the gearboxes of such mechanisms usually incorporate a circular or part-circular gear wheel and/or a rack and pinion mechanism. The forces required to be transmitted by these relatively small components within the gearbox can be considerable, and the gear wheel and rack and pinion is mechanisms are typically around 3 mm thick in order to be sufficiently robust to withstand the forces involved. The use of a substantially circular disc which can rotate within a substantially circular opening enables the use of thinner componentry, for example the drive disc can be around 1 mm thick, thereby permitting a reduction in the critical dimension of the lock mechanism.

Preferably there are two substantially circular discs, each rotating within its own substantially circular opening. The provision of two drive discs reduces the loading which each disc is required to accommodate.

It will be understood that whilst it is desirable to minimise the critical dimension of the lock mechanism (i.e. the dimension which is parallel to the width of the panel frame when fitted) there is substantially no restriction upon the length of the lock mechanism. Thus, the lock mechanism will be aligned with the locking edge of the door; even if the lock mechanism is of significant length it will still be only a small proportion of the length of the locking edge (which may be around two metres, for example).

Preferably, the or each substantially circular opening is provided in a support plate which is substantially fixed in position in use. Preferably also the driving member and the driven member are also respective plates, one lying to either side of the support plate.

Desirably, the periphery of the drive discs includes at least one notch. The notch accommodates a ball bearing which is resiliently biased towards the notch (ideally by a compression spring) whereby to provide a detent position. Preferably there are two notches and two detent positions. In this way, the lock mechanism can io have a first detent position corresponding to the locked position and a second detent position corresponding to the unlocked position.

Preferably, the substantially circular opening(s) in the support plate include an extension, the extension accommodating the ball bearing and the resilient biasing is member of the detent mechanism. Preferably also the driving member and the driven member include slots or channels which can accommodate respective parts of the detent mechanism. In this way, the ball bearing and the resilient biasing member (e.g. compression spring) can be larger than the thickness of the support plate, so that the componeniry of the detent mechanism does not limit the minimum thickness of the support plate or drive discs.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings, in which: Fig.1 shows an exploded view of the components of a door lock incorporating the lock mechanism of the present invention; Fig.2 shows an exploded view as in Fig.1, from a different angle; Fig.3 shows a front view of the assembled components of Fig.1; and Fig.4 shows an exploded view of the lock mechanism according to the invention.

DETAILED DESCRIPTION

The door lock 10 shown in Figs. 1-3 is designed to fit to the (vertical) locking edge of a sliding door (not shown). In a typical sliding door the locking edge carries io most or all of the locking componentry, and in the closed position engages a channel of the mounting frame (also not shown), whereupon the locking componentry can be moved into engagement with keepers located in the mounting frame.

is In its normal orientation of use as shown in Fig.3, the door lock 10 has its longitudinal axis A-A substantially vertical.

The door lock 10 comprises a handle 12 which the user can grasp in order to move the door between its opened and closed positions. The handle 12 is mounted, by way of fixings 14, onto a carriage 16, the fixings 14 passing through holes 18 in the carriage.

The carriage 16 is slidably secured to a mounting bracket 20 by way of the fixings 14, the fixings passing through an elongated slot 22 in the support bracket. The length of the slot is greater than the separation of the fixings 14, whereby the carriage 16 is movable relative to the mounting bracket 20 in the direction of the longitudinal axis A-A.

The mounting bracket 20 can be securely mounted to the locking edge of the door by suitable fixings (not shown).

The mounting bracket 20 also carries the lock mechanism 24. The lock mechanism 24 has a driving member 26 with a blade 30, the blade 30 projecting through an opening 32 in the mounting bracket 20, the blade 30 being clamped between the handle 12 and the carriage 16, whereby movement of the handle 12 and carriage 16 relative to the mounting bracket 20 are communicated to the driving member 26.

As better seen in Fig.4, the driving member 26 is one of three substantially flat plates which make up the major structure of the lock mechanism 24. The driving member 26 lies against a support plate 34, which in turn lies against a driven member 36, the support plate 34 lying between the driving member 26 and the io driven member 36.

A pair of fixing studs 40 pass through the respective slots 42 in the driven member, through the respective holes 44 in the support plate 34, and through the respective slots 46 in the driving member 26. A nut 50 is secured to each fixing is stud 40 whereby the driving member 26, the support plate 34 and the driven member 36 are secured together. The fixing studs 40 each have a collar against which the nut 50 can be tightened, it being ensured that when the nuts 50 are tight the driving member 26 and the driven member 36 can both move relative to the support plate 34 (the slots 42, 46 permitting movement relative to the fixing studs 40 and support plate 34.

The lock mechanism 24 is pre-assembled and then secured to the mounting bracket 20 by way of fixings 52 which locate into threaded recesses in the fixing studs 40. When so assembled, the support plate 34 is fixed relative to the mounting bracket 20, and the driving member 26 and the driven member 36 are movable relative to the mounting bracket 20, in the direction of the longitudinal axis A-A.

The support plate 34 has two substantially circular openings 54 formed therethrough, each opening 54 being circular except for a respective extension 56. Each opening locates a substantially circular drive disc 58, the drive disc being a close sliding fit within the opening 54, and being circular except for four peripheral notches 60.

Each extension 56 locates a respective compression spring 62 and a ball bearing 64, which in the assembled lock mechanism 24 can locate in a notch 60 to define one or more detent positions for the drive disc 58.

In this embodiment the support plate 34 (and also each of the driving member 26 and the driven member 36) is approximately 1 mm thick, so that the critical dimension CD (see Fig.2) of the assembled lock mechanism is around 3 mm.

The lock mechanism 24 in this embodiment does not include a housing so as to io minimise its critical dimension CD.

In order to permit the use of a ball bearing 64 and a compression spring 62 which have diameters greater than 1 mm, the driving member 26 and the driven member 36 each have a slot 68 formed therethrough, the ball bearing 64 and the is compression spring 62 projecting into the slots 68 in the assembled lock mechanism 24 (the slots 68 are ideally of slightly smaller dimension than the diameter of the ball bearing 64 and the compression spring 62 whereby to retain those components within the extension 56).

Only a single slot 68 is shown in each of the driving member 26 and the driven member 36 of Fig.4. It will be understood, however, that the ball bearings 64 and the compression springs 62 occupy only a small proportion of the slots 68, and in another embodiment each single slot 68 could be replaced by a pair of slots positioned to receive a respective ball bearing 64 and spring 62.

Each drive disc 58 carries two projecting drive elements for interconnecting the drive disc with the driving member 26 and the driven member 36. The drive elements project perpendicularly to the plane of the drive disc 58. In this embodiment the drive elements are pegs 66, one of the drive pegs 66 projecting through a drive slot 70 in the driving member 26, the other of the drive pegs 66 projecting through a drive slot 72 in the driven member 36. It will be understood that movement of the driving member 26 in the direction of the longitudinal axis A-A (caused by longitudinal movement of the handle 12 and carriage 16) will cause

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partial rotation of the drive discs 58 within their openings 54, and corresponding (but opposed) movement of the driven member 36.

In an alternative embodiment the drive pegs 66 are replaced by respective raised tabs which are formed as deformations of the drive disc. For example, the periphery of the drive disc can have a pair of radial cuts, the portion of the drive disc between the cuts being bent into a position substantially perpendicular to the plane of the disc so as to provide a raised tab.

It will be understood that is not necessary that the drive slots 70 are closed slots, and the drive slots could alternatively be formed as open-ended recesses communicating with the edge of the drive member and/or driven member. It is also possible that the drive elements of the drive disc engage raised tabs or the like carried by each of the driving member and driven member (although such is embodiments are not preferred as they would likely have a greater critical dimension CD than the embodiment shown.

In another alternative embodiment the projecting drive elements are carried by the respective driving member and driven member, and project into slots or recesses in the drive discs. Other means of interconnecting the drive disc with the driving member and/or with the driven member can be used if desired.

The lock mechanism 24 is connected to two operating members 74, one of which is secured to the driving member 26, the other of which is secured to the driven member 36 (in another embodiment the operating members can be extensions of the respective driving and driven members). Movement of the driving member 26 and driven member 36 causes corresponding movement of the operating members 74 in the direction of the longitudinal axis A-A. The operating members can be connected to locking bars which drive mushroom-headed bolts along the locking edge, and/or can be connected to shoot bolts which locate into keepers in the top and bottom rail of the surrounding mounting frame, in known fashion.

It is arranged that the degree of movement of the driving member 26 corresponds to a particular degree of rotation of the drive discs 58. At one end of the driving discs' range of movement the ball bearing 64 is located in one of the notches 60 of each drive disc, and at the other end of the range of movement the ball bearing 64 is located in another notch 60 of each drive disc, so that the two notches provide detent positions corresponding to the locked and unlocked conditions of the lock mechanism.

It will be understood that the drive discs 58 only require two notches 60. Four io notches 60 are, however, provided in this embodiment, so that the two drive discs 58 are identical, and in particular are not handed. Only a single form of drive disc therefore needs to be manufactured.

It will also be understood that the substantially circular drive discs 58, and the is substantially circular openings 54, provide a relatively large contact area, or bearing surface, as the drive discs 58 rotate. The loading is therefore spread over a relatively large area, permitting the support plate 34 and drive discs 58 to be relatively thin, and in particular significantly thinner than the prior art rack and pinion arrangements. In addition, it is expected that the lock mechanism 24 could be used without lubricating grease.

Whilst the lock mechanism could operate with only one drive disc, the use of two drive discs doubles the bearing surface, and it will be understood that there is little restriction in the size (length) of the components in the direction of the longitudinal axis A-A, so that there is substantially no penalty for the increased length of the lock mechanism caused by the use of two drive discs. Clearly, more drive discs could be used if desired, each additional drive disc reducing the loading on each disc, but it is expected that two drive discs will be able to accommodate the required loading in most applications.

Claims (1)

1. <claim-text>CLAIMS1. A lock mechanism having a driving member and a driven member which move in opposing directions, movement of the driving member being communicated to the driven member by drive componentry, the drive componentry comprising at least one substantially circular drive disc which can rotate within a substantially circular opening and drive elements which interconnect the drive disc with the driving member and with the driven member.</claim-text> <claim-text>2. A lock mechanism according to claim 1 in which the drive elements comprise a first drive peg which is carried by the drive disc and which is located within a drive slot in the driving member, and a second drive peg which is carried by the drive disc and which is located within a drive slot in the driven is member.</claim-text> <claim-text>3. A lock mechanism according to claim 1 or claim 2 in which the drive disc is approximately 1 mm thick.</claim-text> <claim-text>4. A lock mechanism according to any one of claims 1-3 in which the substantially circular opening is provided in a support plate which is substantially fixed in position in use.</claim-text> <claim-text>5. A lock mechanism according to claim 4 in which the thickness of the support plate is substantially the same as the thickness of the drive disc.</claim-text> <claim-text>6. A lock mechanism according to claim 4 or claim 5 in which the driving member and the driven member are also respective plates, lying to opposed sides of the support plate.</claim-text> <claim-text>7. A lock mechanism according to claim 6 in which the thickness of the driving member, and the thickness of the driven member, are substantially the same as the thickness of the support plate. ii</claim-text> <claim-text>8. A lock mechanism according to any one of claims 1-7 in which the periphery of the drive disc includes at least one notch.</claim-text> <claim-text>9. A lock mechanism according to claim 8 in which the at least one notch can accommodate a ball bearing which is resiliently biased towards the notch whereby to provide a detent position.</claim-text> <claim-text>10. A lock mechanism according to claim 9 in which the drive disc has two io notches so as to provide two detent positions.</claim-text> <claim-text>11. A lock mechanism according to claim 9 or claim 10, in which the substantially circular opening includes an extension. the extension accommodating the ball bearing.</claim-text> <claim-text>12. A lock mechanism according to any one of claims 9-11 in which the driving member and the driven member include slots or channels which can accommodate respective parts of the ball bearing.</claim-text> <claim-text>13. A lock mechanism according to any one of claims 1-12 in which there are two substantially circular drive discs, each rotatable within its own substantially circular opening.</claim-text> <claim-text>14. A lock mechanism constructed and arranged substantially as described in relation to the accompanying drawings.</claim-text>