GB2309996A - Pivot bolt with slidable drive member - Google Patents

Abstract

A lock assembly comprising a bolt 32 pivotally mounted upon a support 10, and a drive member 18 slidable with respect to the support, the bolt being provided with a projection 38 engageable with the drive member to move the bolt between an open position and a closed position on sliding movement of the drive member, and wherein when the bolt is in its closed position, further movement of the drive member to a locked position restricts pivotal movement of the bolt with respect to the support. The invention further resides in a hook bolt (32, Fig 7) and deadbolt (48) combination and still further in a bolt (32, Fig 8a) and cam (60) combination.

Description

LOCK ASSEMBLY This invention relates to a lock assembly, and particularly to a lock assembly of the type including a pivotable bolt, for example a hook bolt.

Pivotable hook bolts are commonly used for locking doors, in particular UPVC doors, the hook bolts being provided at locations adjacent the top and bottom of the door, movement of the hook bolts resulting from movement of the door handle, the movement being transmitted to the hook bolts through push rod arrangements.

In order to convert the longitudinal motion of the push rods to rotary motion of the hook bolts, relatively complex transmission arrangements are required. There is the further difficulty that certain hook bolt arrangements can be released by sliding a relatively thin member between the door and the associated jamb to deflect the hook bolt to an open, unlocked position, thus such lock assemblies tend to be relatively insecure.

It is an object of the invention to provide a lock assembly of a relatively simple nature in which the above described disadvantages are reduced.

According to a first aspect of the present invention there is provided a lock assembly comprising a bolt pivotally mounted upon a support, and a drive member slidable with respect to the support, the bolt being provided with a projection engageable with the drive member to move the bolt between an open position and a closed position on sliding movement of the drive member, and wherein when the bolt is in its closed position, further movement of the drive member to a locked position restricts pivotal movement of the bolt with respect to the support.

The drive member is preferably provided with two recesses spaced apart from one another by a wall, the projection engaging the wall to restrict pivotal movement of the bolt when the drive member is in the locked position.

The bolt preferably further comprises a second projection arranged to extend within a first one of the recesses when the bolt is in the closed position, the first projection extending within the other recess when the bolt is in the open position.

A further disadvantage associated with conventional hook bolt assemblies is that unauthorised opening of a door fitted with a hook bolt assembly can be achieved by ievering the door so as to move it within its plane sufficiently to align the closed hook bolt with the open part of its keep and then applying a force at right angles to the plane of the door to move the hook bolt out of alignment with its keep and then permitting the door to return to its original vertical position. A similar technique is applied to release the other hook bolt if one is fitted.

Such doors often include a deadbolt fitted mid-way between upper and lower hook bolts and intended to restrict vertical movement of the door.

However it has been found that the door and its jamb can be flexed to withdraw the dead bolt from its keep and the door can then be flexed out its plane, between the hook bolts so that the dead bolt does not reenter its keep. Thereafter the hook bolts can be overcome as described above.

In addition, certain known hook bolt arrangements include a cam follower arranged to engage a cam surface provided on the door jamb in order firmly to close the door against the door/frame seals as the door is being locked, the cam follower being carried or driven by the hook bolt.

It has been found that if the door is levered in order to gain unauthorised access, the engagement between the cam follower and the cam surface can tend to drive the hook bolt towards an open position.

According to a second aspect of the invention there is provided a lock assembly comprising a pivotable bolt mounted upon a support, drive means for moving the bolt between an open position and a closed position in which it cooperates with a keep, and a deadbolt arrangement located in sufficiently close proximity to the pivotable bolt that when both the pivotable bolt and the deadbolt are in a closed position cooperating with keeps of an adjacent jamb, the deadbolt cooperating with the jamb prevents movement of the relevant part of the door in its plane lengthwise of the jamb to disengage the pivotable bolt from its keep and the pivotable bolt prevents movement of the relevant part of the door in its plane away from the jamb to withdraw the deadbolt from its keep.

It will be recognised that by providing a deadbolt in close proximity to the pivotable bolt, a UPVC door containing such a locking arrangement cannot be opened in the manner described above, the deadbolt ensuring insufficient available vertical movement of the part of the door containing the pivotable bolt to enable the pivotable bolt to be released from its keep. It will further be recognised that the deadbolt may be spaced apart from the pivotable bolt and still produce this effect, provided that the separation of the pivotable bolt and deadbolt is limited to an amount affording insufficient flexure of the door between the pivotable bolt and the dead bolt to withdraw the dead bolt from its keep.

The deadbolt and the pivotable bolt are preferably provided in a single housing, and are conveniently driven by a single drive arrangement.

The pivotable bolt is preferably provided with a projection engageable with a slidable drive member of the drive means to move the pivotable bolt between its open and closed positions, wherein when the pivotable bolt is in its closed position, movement of the drive member to a locked position restricts pivotal movement of the pivotable bolt with respect to the support.

Preferably the deadbolt includes a projection slidable within an angled slot provided in the drive member such that sliding movement of the drive member to move the pivotable bolt towards its closed position moves the deadbolt from an open position towards a closed position.

Further sliding movement of the drive member to the locked position conveniently restricts sliding movement of the deadbolt with respect to the support.

According to another aspect of the invention there is provided a lock assembly comprising a lock member moveable between an open position and a locked position, a drive arrangement for moving the lock member between its open and locked positions, and a cam arrangement arranged to engage a cam surface, the cam arrangement being arranged to be driven by the drive arrangement, wherein operation of the cam arrangement is arranged to occur at a stage prior to movement of the lock member when the drive arrangement is actuated in order to move the lock member from its open position to its closed position.

In use, where the lock assembly is provided on a door having a plurality of hook bolts, it is usual to provide a compressible gasket between the door and its frame, the gasket being compressed when the door is closed and locked. In some arrangements, the action of moving the hook bolts to their locked positions compresses the gasket, the hook bolts including ramped side surfaces which engage respective keeps to compress the gasket. The action of locking the door therefore requires a relatively great deal of effort. In the arrangement of the invention, by using the cam arrangement to compress the gasket prior to movement of the lock members, locking of the door requires less effort.

The invention will further be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a view of part of a lock assembly in accordance with an embodiment of the invention in a locked position; Figure 2 is a view similar to Figure 1 of the assembly in a closed position; Figure 3 is a view similar to Figures 1 and 2 of the assembly in a open position; Figures 4a, 4b and 4 are views of the components of the assembly of Figures 1 to 3; Figure 4d is a view illustrating the components of Figures 4a, 4b and 4c when assembled; Figure 5 is a view of a support for use in a modification; Figure 6 is a view of the drive plate of the modification of Figure 5; Figure 7 is a view illustrating the operation of the modification of Figure 5; Figures 8a, 8k, 8c and 86 are views illustrating the operation of a further embodiment; and Figures 9a and 9b are partial diagrammatic cross-sectional views of the lock assembly in the positions illustrated in Figures 8a and 8c respectively.

The lock assembly illustrated in Figures 1 to 4 comprises a housing defined by a pair of identically shaped generally rectangular support plates 10 each of which is provided with an aperture 12 and an elongate part-circular slot 14. The plates 10 are spaced apart from one another by side walls 16 such that the apertures 12 and slots 14 align with one another. As illustrated in Figure 4d, the side walls 16 extend along the long sides of the support plates 10 and part way along the short sides thereof, thus the housing is open at two of its opposite ends. The side walls 16 are conveniently integral with one of the support plates 10, although they may be separate components.

A pair of identical drive plates 18 are provided within the housing, the drive plates 18 being slidable in a direction parallel to the longitudinal axis of the housing. Each of the drive plates 18 is provided with a generally rectangular cut-out 20 the base surface of which is apertured to define a first generally rectangular recess 22, and a second generally rectangular recess 24 spaced from the recess 22 by a wall 26, the wall 26 including a surface 28 extending substantially parallel to the direction of sliding movement of the drive plates 18. The second recess 24 is partially closed by a rectangular lug 30 extending at right angles from the side wall of the recess 24 remote from the wall 26.

As illustrated in Figure 4d, the drive plates 18 are arranged to slide on the inner faces of respective support plates 10 and are spaced apart from one another by a bolt member 32. As illustrated in Figure 4a, the bolt member 32 is provided with a cut-out 34 so as to be of generally hookshaped form. The faces of the bolt 32 presented to the plates 18 are each provided with three generally cylindrical projections 36, 38, 40.

The first projections 36 on the respective faces of the bolt 32 extend through the cut-outs 20 of each of the drive plates 18 and are rotatably received in the apertures 12 of the respective support plates 10, defining a pivot axis for the bolt 32 about which the bolt 32 can rotate relative to the support plates 10 and drive plates 18.

The second projections 38 are each of length similar to the first projections 36 and extend through the cut-outs 20 of the drive plates 18, the free end of each of the second projections 36 being received in a respective one of the elongate part-circular slots 14 of the support plates 10. The engagement of the second projections 38 in the part-circular slots 14 guides and limits rotational movement of the bolt 32 with respect to the support plates 10. In some applications, the elongate slots 14 may be omitted, and the length of the second projections 38 reduced such that the second projections do not engage the support plates 10.

The third projection 40 of each side of the bolt 32 is substantially shorter than the first and second projections 36, 38, the third projections 40 being arranged to extend within the cut-outs 20 but not to engage the support plates 10.

In use, the housing is mounted upon a door or other object to be locked and the drive plates 18 are connected to push rods moveable by the handle or other actuator of the door. Starting from the position illustrated in Figure 1, it will be recognised that the bolt 32 is in an extended, closed position and that in this position, unless the drive plates 18 are moved with respect to the support plates 10, rotation of the bolt 32 with respect to the support plates 10 is not permitted, the engagement of the second projections 38 in the elongate slots 14 restricting anticlockwise rotation of the bolt 32 with respect to the support plates 10 and the engagement of each second projection 38 with the surface 28 of the respective wall 26 restricts clockwise movement of the bolt 32 with respect to the support plates 10. Rotation of the bolt 32 with respect to the support plates 10 is further restricted by engagement of each third projection 40 with the respective projection 30 provided on the drive plates 18 partially closing the second recesses 24. It will be understood that in this position, the bolt 32 is locked in its closed position, hooked behind a keep on the respective door jamb and hence unauthorised opening of the door for example by attempting to force the bolt 32 in a clockwise direction to move the bolt 32 to its open position is resisted.

In order to open the lock assembly, the drive plates 18 are moved towards the left as illustrated in Figures 1, 2 and 3. As illustrated in Figure 2, the drive plates 18 have been moved to the left by a relatively small amount to a position in which each third projection 40 engages the respective wall 26, and the second projections 38 are no longer in engagement with the surfaces 28 of the walls 26. Once this position has been reached the plates 18 are no longer locking the bolt 32 in its closed position and further movement of the drive plates 18 towards the left results in clockwise movement of the bolt 32 with respect to the support plates 10 initially as a result of the engagement of the third projections 40 with the walls 26 resulting in the second projections 38 entering the first recesses 22. Subsequent movement of the drive plates 18 results in engagement of the second projections 38 with the righthand walls of the first recesses 22, the bolt 32 being driven in a clockwise direction by the engagement of the second projections 38 with the drive plates 18. Movement of the drive plates 18 towards the left as illustrated eventually results in the second projections 38 reaching positions in which they each engage an end of the respective elongate part-circular slots 14 and thus further movement of the bolt 32 and hence of the drive plates 18 is prevented. Such a position is illustrated in Figure 3.

Movement of the bolt 32 from the open position described above to the closed position occurs as a result of movement of the drive plates 18 towards the right from the position illustrated in Figure 3. As illustrated, the first and second recesses 22, 24 are defined by substantially perpendicular end faces defining the wall 26. The interconnection of the end faces of the wall 26 with the surface 28 are curved so as to permit the second projection 38 to ride from the end face of the first recess 22 to the surface 28 as movement of the drive plates 18 towards the right occurs. Once the second projection 38 has reached the surface 28 of the wall 26, further rotation of the bolt 32 with respect to the support plate 10 does not occur. This position is illustrated in Figure 2. Once in this position, if a force were applied to the bolt 32 to move the bolt 32 in a clockwise direction, such a force would tend to move the drive plates 18 towards the left returning the lock assembly to the position illustrated in Figure 3. In order to prevent such movement, the drive plates 18 are moved to the right until they occupy the locked position illustrated in Figure 1, the bolt 32 remaining in its closed position as illustrated in Figures 1 and 2. As described above, once the drive plates 18 are in their locked positions, both clockwise and anti-clockwise movement of the bolt 32 with respect to the support plates 10 is resisted.

The lock assembly illustrated in Figures 5 to 7 comprises a pivotable bolt arrangement similar to that described with reference to Figures 1 to 4, and like reference numerals will be used herein to denote like parts of the assembly.

In the assembly illustrated in Figures 5 to 7, each of the support plates 10 are provided with respective aligned lateral slots 42. The drive plates 18 are each provided with angled slots 44, the slots 44 each including an end region 46 extending in the direction of sliding movement of the drive plates 18 with respect to the support plates 10. Throughout the permitted range of sliding movement of the drive plates 18 with respect to the support plates 10, the slots 42 and the angled slots 44 overlap one another.

A deadbolt 48 is slidable at right angles to the length of the support plates 10 between an extended position as illustrated in Figure 7 and a retracted position in which the deadbolt is housed substantially entirely within the housing defined by the support plates 10 and sidewalls 16, the sidewall 16 forming one of the long sides of the housing including an opening through which the deadbolt 48 extends when it is in its extended position.

The deadbolt 48 is provided with a pair of oppositely extending projections 50 each of which extends through the angled slot 44 of a respective one of the drive plates 18 and the slot 42 of the corresponding support plate 10.

Starting from the position illustrated in Figure 7 in which movement of both the dead bolt 48 and pivotable bolt 32 is restricted by the engagement of their respective projections 38, 50 with the surface 28 and sidewalls defining the end regions 46 of the slots 44, movement of the drive plates 18 to the right as shown in Figure 7 moves the end regions 46 and the surfaces 28 away from the projections 50, 38 thus permitting the deadbolt 48 and pivotable bolt 32 to move with respect to the support plates 10. The movement of the pivotable bolt 32 is as described with reference to the embodiment of Figures 1 to 4, noting that the Figure 7 embodiment is arranged such that the opening movement of the pivotable bolt 32 is in an anticlockwise direction rather than clockwise as in Figures 1 to 4.

Continued movement of the drive plates 18 with respect to the support plates 10 results in the projections 50 being driven along the slots 42 by coaction with the moving, angled slots 44, to retract the deadbolt 48.

The embodiment of Figures 5 to 7 is intended to be used in conjunction with a keep provided on the door frame, the keep including a part shaped to receive the pivotable bolt 32, and an opening or recess for receiving the dead bolt 48. When the lock assembly is in the state where the pivotable bolt 32 is in its locked position hooked behind the corresponding part of the keep and the deadbolt 48 is received in the opening or recess, vertical movement of the door in order to release the pivotable bolt 32 from the corresponding part of the keep is resisted by the engagement of the deadbolt 48 in the opening or recess, the dead bolt 48 and pivotable bolt 32 being sufficiently close that insufficient flexing of the door between the dead bolt and the pivotable bolt is possible to enable the pivotable bolt 32 to be released from the keep. Similarly the pivotable bolt 32 prevents the door being moved or flexed away from the jamb carrying the keep by sufficient distance to withdraw the dead bolt 48 from the keep.

It will be understood that the deadbolt 48 may be provided in a housing separate from that of the pivotable bolt 32 and still achieve this function, and further that the bolts 32, 48 need not be driven by a common drive mechanism.

Although the provision of the deadbolt is described above as being in close proximity to a pivotable bolt driven using the drive arrangement of the embodiment of Figures 1 to 4, it will be recognised that other drive arrangements could be used in order to move the pivotable bolt between its open and closed positions.

Figures 8a, 8b, 8g and 8d illustrate an arrangement including a pivotable bolt 32 and a dead bolt 48 provided within a single housing and driven by a common drive arrangement. Such a lock assembly is similar to that illustrated in Figures 5 to 7, and other than as described hereinafter, operation of the arrangement of Figures 8a, 8b, 8c and 8d is as described hereinbefore with reference to Figures 5 to 7.

The main difference between this embodiment and that of Figures 5 to 7 is that a cam roller 60 is provided on the push rod of the drive arrangement which, in use, is used to move the drive plates 18 and hence to drive the pivotable bolt 32 and deadbolt 48. The cam roller 60 is arranged to engage a cam surface 62 provided on a door jamb 64, window frame or the like (see Figures 9a and 9k) and positioned such that when the door or window upon which the lock assembly is mounted is moved to its closed position, movement of the roller 60 from the position illustrated in Figures 8a and 9a to that of Figures 8c and 9b causes the roller 60 to ride along the cam surface 62 pushing the door or window into a fully closed position. Such movement is often required where a compressible gasket 66 is provided between the door and jamb or window and frame, the action of the roller 60 on the cam surface 62 resulting in the gasket 66 being compressed to form a seal between the door and jamb or window and frame. For the sake of clarity, Figure 9 is not to the same scale as Figure 8.

The lock assembly illustrated in Figures 8 and 9 is arranged such that the initial movement of the drive plates 18 away from the position illustrated in Figure 8a does not result in movement of the pivotable bolt 32 or deadbolt 48, and it is this movement of the push rods and, consequently, the drive plates 18 which is used to move the roller 60 in order to fully close the door or window. It will be recognised that by arranging for such movement of the roller 60 to occur prior to rather than during movement of the pivotable bolt 32 and deadbolt 48, the maximum load required to move the push rods and drive plates 18 is reduced. This is of particular benefit to the user by comparison with certain known arrangement where the cam action pressing the door closed and compressing the sealing gasket around the door, is achieved by ramp surfaces on the side faces of the bolts 32 and/or 48, the user having the benefit of easier operation when locking and unlocking the door.

It will be recognised that the shapes of the drive plates 18 and bolt 32 may be changed without significantly effecting the operation of the lock assembly, and it is intended that such variations fall within the scope of the present invention. The bolt 32 and its keep may include cam formations whereby the action of engaging the bolt 32 in the keep moves the door further in the closing direction to compress seals interposed between the door and the door frame.

Claims (11)

1. A lock assembly comprising a bolt pivotally mounted upon a support, and a drive member slidable with respect to the support, the bolt being provided with a projection engageable with the drive member to move the bolt between an open position and a closed position on sliding movement of the drive member, and wherein when the bolt is in its closed position, further movement of the drive member to a locked position restricts pivotal movement of the bolt with respect to the support.

2. A lock assembly as claimed in Claim 1, wherein the drive member is provided with two recesses spaced apart from one another by a wall, the projection engaging the wall to restrict pivotal movement of the bolt when the drive member is in the locked position.

3. A lock assembly as claimed in Claim 1 or Claim 2, wherein the bolt further comprises a second projection arranged to extend within a first one of the recesses when the bolt is in the closed position, the first projection extending within the other recess when the bolt is in the open position.

4. A lock assembly comprising a pivotable bolt mounted upon a support, drive means for moving the bolt between an open position and a closed position in which it cooperates with a keep, and a deadbolt arrangement located in sufficiently close proximity to the pivotable bolt that when both the pivotable bolt and the deadbolt are in a closed position cooperating with keeps of an adjacent jamb, the dead bolt cooperating with the jamb prevents movement of the relevant part of the door in its plane lengthwise of the jamb to disengage the pivotable bolt from its keep and the pivotable bolt prevents movement of the relevant part of the door in its plane away from the jamb to withdraw the deadbolt from its keep.

5. A lock assembly as claimed in Claim 4, wherein the deadbolt and the pivotable bolt are provided in a single housing, and are driven by a single drive member.

6. A lock assembly as claimed in Claim 4 or Claim 5, wherein the pivotable bolt is provided with a projection engageable with a slidable drive member of the drive means to move the pivotable bolt between its open and closed positions, and wherein when the pivotable bolt is in its closed position, movement of the drive member to a locked position restricts pivotal movement of the pivotable bolt with respect to the support.

7. A lock assembly as claimed in any one of Claims 4 to 6, wherein the deadbolt includes a projection slidable within an angled slot provided in the drive member such that sliding movement of the drive member to move the pivotable bolt towards its closed position moves the dead bolt from an open position towards a closed position.

8. A lock assembly as claimed in Claim 7, wherein further sliding movement of the drive member to the locked position restricts sliding movement of the deadbolt with respect to the support.

9. A lock assembly comprising a lock member moveable between an open position and a locked position, a drive arrangement for moving the lock member between its open and locked positions, and a cam arrangement arranged to engage a cam surface, the cam arrangement being arranged to be driven by the drive arrangement, wherein operation of the cam arrangement is arranged to occur at a stage prior to movement of the lock member when the drive arrangement is actuated in order to move the lock member from its open position to its locked position.

10. A lock assembly as claimed in any one of Claims 1 to 8, further including a cam arrangement arranged to engage a cam surface, the cam arrangement being arranged to be driven by the drive arrangement of the or each bolt and wherein operation of the cam arrangement is arranged to occur at a stage prior to movement of the or each bolt when the drive arrangement is actuated in order to move the or each bolt from its open position to its locked position.

11. A lock assembly substantially as hereinbefore described with reference to any one of the accompanying drawings.