GB2338507A

GB2338507A - Lock mechanism restraint

Info

Publication number: GB2338507A
Application number: GB9813362A
Authority: GB
Inventors: Bernard John Viney
Original assignee: Surelock McGill Ltd
Current assignee: Surelock McGill Ltd
Priority date: 1998-06-19
Filing date: 1998-06-19
Publication date: 1999-12-22
Anticipated expiration: 2018-06-19
Also published as: GB2338507B; GB9813362D0

Abstract

A lock mechanism for security vehicle lockers comprises bolts 10, 12 movable longitudinally between projecting locking positions and retracted unlocked positions, and restraint means 86 moveable transversely to engage one bolt and prevent the bolts moving to the unlocked position. The restraint comprises a plunger 96 normally withdrawn by solenoid 94, but if its power is cut, the plunger is spring-urged into a flared opening 84 in the bolt. The distal end of the plunger is necked 102 and carries a flange 104, which cooperating with the opening resists any attempt to force the unlocking of the bolts.

Description

- 1 LOCK MECRMIS 2338507 The present invention relates to a lock mechanism

and in particular, but not exclusively, to a lock mechanism for use in conjunction with a moveable member hinged within a frame.

In the past, it has been the practice of security firms to transport precious items from one location to another within a vehicle fitted with a number of external security features. However, within the vehicle itself, the precious items have often been stored in any way that has been convenient and, in some cases, this has meant simply lying on the floor. More recently, a number of security firms have taken to installing lockers within the security vehicle in which to place the items to be transported. These lockers are typically closed by a door hinged to one side of the locker and the door provided with a means by which it may be locked in the closed position. It has been found that, even though the external security features of the vehicle are themselves difficult to overcome, the provision of internal, individuallylockable lockers acts as a further deterrent to the would-be criminal who, having gained access to the interior of the vehicle, is then faced with the time consuming process of breaking into a large number of locked lockers, many of which on any particular occasion might be empty, in order to locate the valuable items being transported.

The lock mechanism of the present invention is particularly suited for locking the lockers within a security vehicle. However, the present lock mechanism may also be used to lock other forms of moveable member within a frame to which they are hinged. This is particularly true where the member concerned has dimensions which enable a single lock mechanism of type to be described to lock opposite sides of the moveable member to the surrounding frame.

According to the present invention there is provided a lock mechanism comprising at least one bolt member moveable in a first direction between a projecting, locking position and a retracted, unlocked position; actuating means for moving said bolt member between said positions; and restraint means moveable in a second direction between a first position in which said restraint means engages said bolt member and prevents said bolt member from moving from said projecting, locking position to said retracted, unlocked position and a second position in which said bolt member is not so prevented, said second direction being transverse to said first direction and said restraint means being shaped so as to present a confronting surface to said bolt member having a component in said first direction so that when said restraint means is in said first position and said actuating means is actuated to increase the contact force between said bolt member and said restraint means, an attempt to move said restraint means from said first position to said second position brings the confronting surface into engagement with said bolt member thereby preventing further movement of said restraint means.

Advantageously, said second direction is orthogonal to said first direction.

Advantageously, said restraint means engages a cut-out portion of said bolt member when said restraint means is in said first position.

Advantageously, said cut-out portion comprises an aperture in said bolt member.

Advantageously, said cut-out portion comprises a 3 - 1 is throughbore through said bolt member.

Advantageously, said throughbore is flared outwardly in said second direction in a direction away from said restraint means.

Advantageously, said cut-out portion comprises an edge formation provided on said bolt member.

Advantageously, said restraint means comprises a plunger and said confronting surface comprises a radial flange provided on a distal end of said plunger.

Advantageously, said restraint means is biased toward said first position by biasing means.

Advantageously, said restraint means comprises a plunger of a solenoid.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is a view of the internal workings of a lock mechanism; Figure 2 is a cross-sectional view taken along lines II-II of Figure 1; Figure 3 is an end view of the lock mechanism of Figure 1; Figure 4 is a plan view of the lock mechanism of Figure 1; and Figure 5 is a view showing the external appearance of the lock mechanism of Figure 1.

Referring to Figure 1, there is shown a lock mechanism comprising two bolt members 10 and 12 mounted for reciprocating movement on a base plate 14, both of which are in intermeshing engagement with a central drive gear 16.

The base plate 14 is rectangular in shape and has dimensions such that it has a length substantially equal to or slightly less than the door or other 4 - i moveable member to which the lock mechanism is to be attached. The drive gear 16 is positioned substantially centrally of the base plate 14 and is fixedly mounted on an axle 20. The axle 20 extends perpendicularly to the base plate 14 and is supported for rotation, to one side of the drive gear 16, within a circular aperture 22 formed in the base plate and, on an opposite side of the drive gear, by a circular aperture 24 formed in a cover plate 26. The cover plate 26 extends substantially parallel to the base plate 14 and is held in spaced relationship thereto by means of the receipt of two screws 28 and 30 which pass through countersunk apertures 32 and 34 provided in the cover plate and into threaded engagement with a is correspondingly threaded blind bore 36, 38 of a respective boss 40, 42 provided on the base plate. In addition to the countersunk apertures 32 and 34, the cover plate 26 is also provided, at a location spaced from circular aperture 24, with a further aperture 43.

A handle 44 is mounted on an external surface 46 of the base plate 14 and journaled to the axle 20 such that, unless otherwise impeded, a rotation of the handle brings about a corresponding rotation of the drive gear 16.

The bolt members 10 and 12 extend in opposite directions longitudinally of the base plate 14 and are each moveable between an extended position in which the bolt members project from the base plate and a retracted position in which they do not. For ease of manufacture, the two bolt members 10 and 12 may be made so as to be identical even though, as a result, not all the features of both bolt members find use in the operation of the lock mechanism. Because of this, and for the sake of clarity, the present description will be limited for the time being to bolt member 10 even though the corresponding features can also be found in relation to bolt member 12.

As previously stated, bolt member 10 extends longitudinally of the base plate 14 and has an end 48 remote from the drive gear 16 to which there is attached a cylindrical projecting rod 50. The rod 50 also extends longitudinally of the base plate 14 and has an end 52 remote from the drive gear 16 which tapers to a reduced diameter. Immediate this tapered end 52 and the end attached to the bolt member 10, the projecting rod 50 extends through a channel 54 defined between a guide 56 and the base plate 14 to which it is attached. The guide 56 is of substantially Ushaped cross-section and is attached to the base plate is 14 by means of screws 58 and 60 which pass through apertures provided in lateral flanges 62 and 64.

At the opposite end, the bolt member 10 is necked so as to provide a section 66 of reduced lateral dimensions which enables the bolt member to pass to one side of the drive gear 16 without protruding laterally of the base plate 14. This necked section 66 is received between the base plate 14 and the cover plate 26 and is held in spaced relationship to the first of these by means of a spacer 68. The spacer 68 comprises a stud portion 70 of reduced diameter which engages an aperture 72 provided in the base plate 14 and an enlarged head portion 74 which extends between the base plate 14 and the bolt member 10. The head portion 74 tapers to a reduced diameter at an end remote from the base plate 14 and is provided with a shallow blind bore 76.

The necked section 66 is provided with a rack 78 on the side of the bolt member 10 which faces towards the drive gear 16 such that the teeth of the drive gear intermesh with the teeth of the rack to drive the 6 bolt member between the extended and retracted positions. In addition to this, the bolt member 10 additionally provided with two longitudinally spaced cut-out portions 80 and 82 on the same side of the bolt member as the rack 78 but in a region spaced from the necked section 66. The bolt member 10 is also provided with a throughbore 84 which, when the bolt member is in the extended position, is in alignment with the further aperture 43 provided in the cover plate 26. As shown in Figures 2 and 4, the throughbore 84 is flared in that the diameter of the throughbore on a side of the bolt member adjacent the base plate 14 is greater than the diameter of the throughbore on a side of the bolt member adjacent the cover plate 26.

As previously stated, although the features of the bolt members have been described solely with reference to bolt member 10, bolt member 12 also possesses the described features which are accordingly indicated by the same reference numerals in the accompanying drawings.

Adjacent to one of the bolt members, in this case bolt member 12, there is positioned a housing 86 which is mounted with respect to the base plate 14 by means of the receipt of a screw 83 which passes through an aperture provided in the base plate and into threaded engagement with a correspondingly threaded bore 85 provided in the housing. In addition to the threaded bore 85, the housing 86 is formed with a laterally extending, blind bore 88 in which there is positioned a ball-bearing 90 which is biased outwardly of the bore by means of a spring 92. However, this outward movement of the ball-bearing 90 is restricted by its engagement with a side of the bolt member 12, the point of contact moving along the bolt member as the is 7 bolt member moves between the extended and retracted positions. Nevertheless, the ball-bearing 90 is sized so as to be capable of at least partial receipt within a respective one of cut-out portions 80 and 82 as and when either of these portions are aligned opposite the blind bore 88.

As well as housing the ball-bearing 90, the housing 86 also provides support for a solenoid 94 which is arranged so that its plunger 96 is capable of reciprocal movement along an axis perpendicular both to the bolt member 12 and the underlying base plate 14. A switch 98 is also carried by the housing 86 and is connected to the solenoid 94 in such a way as to sense whether the plunger 96 is in an extended or a is retracted position.

The plunger 96 is shaped so that towards its distal end it necks at shoulder 100 to define a portion of reduced diameter 102. This portion 102 in turn terminates in a radial flange 104 of increased diameter. Nevertheless, the radial flange 104 is sized so as to be capable of insertion through both the further aperture 43 provided in the cover plate 26 and the throughbore 84 provided in the bolt member 12 whereupon it is received within the blind bore 76 of spacer 68.

In use, and with the plunger 96 held in its retracted position by the action of the solenoid 94 so that no portion of the plunger extends into throughbore 84, it is possible to move the bolt members 10 and 12 between their extended and retracted positions by simply rotating handle 44.

Clearly, when the bolt members 10 and 12 are in their extended positions, the cylindrical projecting rods 50 may be used to engage keepers (not shown) in a frame to which the moveable member fitted with the 8 - lock mechanism is hinged thereby locking the member with respect to the frame. Only when the bolt members 10 and 12 are moved to their retracted positions are the cylindrical projecting rods 50 withdrawn from the keepers thereby releasing the member for further hinged movement.

Rotating the handle 44 causes a rotation of the axle 20 to which the drive gear 16 is journalled and rotation of the drive gear causes an equal and opposite movement of the two bolt members 10 and 12 by virtue of the engagement of the drive gear with the racks 78. Thus an anticlockwise rotation of the drive gear 16 from the position shown in Figure 1 would cause bolt member 10 to move to the right and bolt member 12 to move to the left thereby withdrawing cylindrical projecting rods 50 from the projecting position in which they are shown. Throughout this movement the bolt members 10 and 12 are guided by their engagement with the drive gear 16 and the spacers 68, as well as by the receipt of the cylindrical projecting rods 50 to which they are attached within the channels 54 of the guides 56.

At the same time the ball-bearing 90 is continually urged out of the blind bore 88 and into engagement with a side edge of bolt member 12 by means of spring 92. As a result, whenever either one of the cut-out portions 80 or 82 is opposite the blind bore 88, the ball-bearing 90 is biased into engagement with the cut-out portion concerned and, although the cutout portions are sufficiently shallow that a further rotation of handle 44 is sufficient to push the ballbearing 90 back into the blind bore 88 against the action of the spring 92, nevertheless this provides the lock mechanism with a positive feel enables a user to easily locate both the extended and retracted 9 - positions.

If the power to the solenoid 94 is cut, either as a consequence of an attempted forced entry or by means of a remote switch (not shown), the plunger 96 will no longer be capable of being held in the retracted position against the action of the solenoid spring (also not shown) which will tend to bias the plunger into engagement with the bolt member 12. If the bolt member 12 should happen to be in a position other than the extended position, this will simply mean that the radial flange 104 will bear against the bolt member but not to such an extent as to prevent its further movement by means of the handle 44. However, if the bolt member 12 is moved to the extended position so is that the throughbore 84 is aligned with the further aperture 43 provided in the cover plate 26, the solenoid spring will cause the plunger 96 to project through the throughbore 84 and into the blind bore 76 of the underlying spacer 68. Once in this position it is no longer possible to retract the bolt member 12 simply by means of the handle 44 and, since bolt member 12 is drivingly connected to bolt member 10 via drive gear 16, it also becomes impossible to retract bolt member 10 as well.

In the past with similar systems, but where the plunger does not terminate in a radial flange, it has been possible to "bounce" the plunger out of engagement with the throughbore provided in the bolt member, enabling the lock mechanism to once again be unlocked simply by rotating the handle. In order to do this, the handle was rotated slightly, thereby bringing the plunger into engagement with an edge of the throughbore and, with the handle held in this position, the outside of the lock mechanism was struck in such a way ad to cause the plunger to retract i 1 i i 1 i 1 i against the action of the solenoid spring. If the handle was pre-loaded correctly it was possible to arrive at a situation in which the friction generated between the plunger and the edge of the throughbore was sufficient to prevent the plunger returning to its original position after being struck under the action of the solenoid spring but not sufficient to prevent it retracting in the first place. Accordingly, by repeatedly striking the outside of the lock mechanism it was possible to work the plunger back and out of engagement with the throughbore. This however, is not possible with the lock mechanism of the described embodiment. By providing the plunger 96 with a radial flange 104, if an attempt were to be made to pre-load the handle 44 prior to striking the outside of the lock mechanism, all that would be achieved would be to bring an edge of the throughbore 84 into engagement with the shoulder defined at the intersection of the radial flange 104 and the reduced diameter portion 102. Subsequent striking of the outside of the lock mechanism would then only cause the radial flange 104 to abut that portion of the bolt member 12 surrounding in the throughbore 84 and this in turn would prevent the plunger 96 from retracting. Accordingly, the present lock mechanism provides considerable advantages in terms of added security over the lock mechanisms of the prior art.

In this context, the flared nature of the throughbore 84 also provides the present lock mechanism with advantages over the prior art in that it obviates any problems caused as a result of misalignment or tolerance build-up during the manufacturing process.

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Claims

1. A lock mechanism comprising at least one bolt member moveable in a first direction between a projecting, locking position and a retracted, unlocked position; actuating means for moving said bolt member between said positions; and restraint means moveable in a second direction between a first position in which said restraint means engages said bolt member and prevents said bolt member from moving from said projecting, locking position to said retracted, unlocked position and a second position in which said bolt member is not so prevented, said second direction being transverse to said first direction and said restraint means being shaped so as to present a confronting surface to said bolt member having a component in said first direction so that when said restraint means is in said first position and said actuating means is actuated to increase the contact force between said bolt member and said restraint means, an attempt to move said restraint means from said first position to said second position brings the confronting surface into engagement with said bolt member thereby preventing further movement of said restraint means.

2. A lock mechanism in accordance with Claim 1, wherein said second direction is orthogonal to said first direction.

3. A lock mechanism in accordance with Claim 1 or Claim 2, wherein said restraint means engages a cutout portion of said bolt member when said restraint means is in said first position.

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4. A lock mechanism in accordance with Claim 3, wherein said cut-out portion comprises an aperture in said bolt member.

5. A lock mechanism in accordance with Claim 3 or Claim 4, wherein said cut-out portion comprises a throughbore through said bolt member.

6. A lock mechanism in accordance with Claim 5, wherein said'throughbore is flared outwardly in said second direction in a direction away from said restraint means.

is

7. A lock mechanism in accordance with Claim 3, wherein said cut-out portion comprises an edge formation provided on said bolt member.

8. A lock mechanism in accordance with any preceding claim, wherein said restraint means comprises a plunger and said confronting surface comprises a radial flange provided on a distal end of said plunger.

9. A lock mechanism in accordance with any preceding claim, wherein said restraint means is biased toward said first position by biasing means.

10. A lock mechanism in accordance with any preceding claim, wherein said restraint means comprises a plunger of a solenoid.

11. A lock mechanism substantially as herein described with reference to the accompanying drawings.