GB2086974A - A locking mechanism for a floor safe - Google Patents

Abstract

A locking mechanism having a pair of locking bolts (17, 19) interconnected for movement in unison. One of the locking bolts (17) is tumbler-controlled, the other bolt (19) being arranged to operate a pair of pivotally mounted locking arms (11) to effect lock closure when the bolts (17, 19) move upon tumbler actuation. An auxiliary bolt (22) is constrained for movement into the path of travel of the locking bolt (19). The bolt (22) has a connecting rod (23) engaging one or more of the tumblers in such a way that the bolt (22) is movable out of the path of travel of the bolt (19) by the tumblers upon tumbler actuation of the locking mechanism. <IMAGE>

Description

SPECIFICATION A locking mechanism, particularly for a floor safe Field of the Invention The present invention relates to a locking mechanism. The locking mechanism is particularly useful for a floor safe, but has other applications as well.

Background of the invention Floor safes are particularly useful in shops, garages and clubs but can be used in the home to protect all forms of valuables and cash against attacks by force, drills and explosives.

Normally the safes are buried in the floor in reinforced concrete thereby to prevent removal from the premises in which they are installed. Only the door locking unit of the safe is visible together with a deposit tube when fitted, and these units are specially designed to resist attack by the various methods listed above.

Known designs of door locking unit are usually made of solid steel incorporating special drillresisting protection. They are provided with either a keyless combination locking mechanism or a standard lever key lock to secure the door unit to the safe. Additionally a live relocking device may be fitted to prevent opening of the door locking unit if the main locking mechanism is disturbed.

The door locking unit is locked to the safe by means of one or more bolts interengaging in corresponding receiving recesses in the neck of the safe. Securing of the bolts in the locked position is then carried out by employing a dead lock or combination lock or similar. The bolts may be radially spaced around the door unit thus ensuring a locking action at predetermined spaced positions on a circumferential basis with respect to the safe neck.

In my copending U.K. Patent Application 7928775 Serial No. 2057043 there is disclosed a door locking unit for a floor safe incorporating a pair of pivotally mounted elongate locking arms around the door unit, the arms being normally urged together at their free ends. The mechanism includes a pair of interconnected slidable bolts for movement in unison, one of which is tumblercontrolled by combination or ordinary key lock, to move the other bolt between the free ends of the arms to shift them apart so that substantially the whole longitudinal extent of each locking arm is movable into locking cooperation with the safe housing.

Such a locking mechanism has provided to be a considerable advance in safe protection, but up till now it has not been found possible to provide the mechanism with live relocking facilities in an uncomplicated and inexpensive manner, whereby the movable bolt operating the pivotal locking arms, remains held in the locking position even when the main locking mechanism, that is the ordinary key lock or combination lock, has been disabled by unauthorised means.

Summary of the Invention According to the invention there is provided a locking mechanism comprising tumbler-controlled locking bolt means movable between an unlocking and locking position, and an auxiliary locking member constrained for movement into the path of travel of said locking bolt means to prevent movement thereof from said locking position, said locking member being actuable out of said path of travel in response to movement of one or more of the tumblers during lock operation to allow movement of the bolt means between said locking and unlocking positions.

With this arrangement live relocking is attainable by tapping directly into tumbler action, so that the necessity of incorporating additional structural elements into the locking mechanism to achieve live relocking, is kept to the minimum. In particular live relocking is achieved with the single movement of operating the main locking mechanism to open and close the lock either by key lock or similar lock action.

This is in contrast to previous systems wherein the live relocking action is a separately performed movement from the main engaging bolt configuration.

Brief Description of the Drawings An embodiment of the invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a cross-sectional view through the top part of a floor safe showing a door locking unit mounted in the safe opening, the unit incorporating a locking mechanism according to an embodiment of the invention; Figure 2 is an underneath view of Figure 1 with the locking mechanism cover removed; Figure 3 is a detail of the auxiliary locking bolt of the locking mechanism; and Figure 4 is a view of the interior of a dead lock as used in the locking mechanism with the top casing half removed for purposes of illustration.

Detailed Description of a Preferred Embodiment The housing 1 of the safe shown in the drawings has an opening 2 in which is mounted a generally cylindrical steel collar 2. The collar 2 is provided with an annular flange 4 defining an opening 5 to the interior of the safe housing 1.

The safe housing 1 is normally buried in the floor and covered by reinforced concrete to the level of the top of the collar 2, with only the cylindrical well 6 formed by the collar being accessible.

A door locking unit 7 for the safe is mounted in the well 6 as shown in Figure 1. The door locking unit 7 is formed of solid steel having a cylindrical head portion 8 and a depending barrel portion 9 of lesser diameter. The depending barrel portion 9 is provided with an annular recess 10 shown in dotted outline in Figure 1. The head portion 8 is provided with a pivotally mounted handle 20 for lifting the unit 7 from the well 6.

The door locking unit 7 is provided with a locking device in the form of a dead lock 1 5 attached to the base of the depending barrel portion 9. The lock 15, the basic construction of which will be well-known to those skilled in the art, is more particularly shown in Figure 4 and will be referred to in more detail later with regard to those features which are necessary for an understanding of the invention. A cover 21 formed of a stiff plastics material is attached to the bottom of the barrel portion 9 to enclose the lock 1 5. The lock 15 is actuabie by a key 1 6 having a keyway through the head portion 8 and barrel portion 9. It will be appreciated at this point that the locking device need not necessarily be a dead lock but may, for example, be a combination lock.

The tumbler-controlled bolt 1 7 of the lock 1 5 is attached by means of a shaft 1 8 to another bolt 1 9 mounted for movement across the diameter of the barrelled portion 9 as shown in Figure 2, so that the bolts 1 7 and 1 9 are movable in unison upon operation of the key 1 6.

A pair of semi-circular arms 11 are pivotally mounted at respective ends thereof around the barrel portion 9. The arms 11 are urged together about their point of pivot so that their other ends 13 come into normal contact by means of a tension spring 14 connected between the arms 11 and through a passageway (not shown) in the barrel 9. In the drawings the arms 11 are shown in their open position with the bolt 19 interposed therebetween as will be described shortly.

The arms 11 are of such a radius that in their normally closed position with the ends 13 in contact they fully occupy the annular recess 10 and merge flush with the outer surface of the barrel portion 9.

In the closed position of the arms 11 the barrel portion 9 may be inserted and withdrawn through the opening 5 in the collar 2 as shown in Figure 1.

The bolt 1 9 serves to open the ends 1 3 of the arms 11 to cause them to pivot about point 12 and away from the barrel portion 9, as will be seen in Figure 2, when the bolt 1 7 is actuated by the key 16. The bolt 1 9 in Figures 1 and 2 is shown in its forward position, that is at a position to separate and lock apart the arms 11, and in this position the forward end of the bolt 1 9 is flush with the outer surface of the barrel portion 9.

When the bolt 1 9 is withdrawn the arms 11 move into respective recesses 10 by the action of spring 14,until their free ends 1 3 are in contact.

It will be appreciated that in the forward position of the bolt 1 9 as shown in Figures 1 and 2, the arms 11 move out from the respective recesses 10 to pass beneath the flange 4 of the collar 2 to thereby lock the door locking unit in position in the opening 5. The arrangement as described provides circumferential interaction between the locking arms 11 and the lower surface of the flange 4 when an attempt is made to lift the door locking unit from the well 6 by means of the handle 20. In addition, although not shown, the bolt 19 may be arranged to protrude beyond the outer surface of the barrel portion 9 in the forward position, to provide a further interacting surface with the flange 4.

An auxiliary locking bolt 22 is shown slidably mounted in the barrel portion 9 and in the plane of movement of the locking arms 11. The auxiliary bolt 22 is spring urged by means of a spring 24 in a path of travel transverse to the path of travel of the locking bolt 19 as will be seen from Figure 2, and the detail of the auxiliary bolt shown in Figure 3. The auxiliary locking bolt 22 moves under the action of spring urging to abut the rear of the bolt 19 in its forward position to thereby prevent withdrawal of the bolt 1 9 by unauthorised tampering of the main locking mechanism constituted by the dead lock 15.

The auxiliary bolt 22 is provided with a connecting rod 23 extending axially of the barrel portion 9. As more particularly shown in Figure 4, the rod 23 passes through a slot 15A (shown in dotted outline) in the top removed half of the casing 1 5B of the lock 1 5, such that in either the forward or withdrawn positions of the bolt 1 9, the rod 23 bears against the drop lever 1 5C of the lock tumblers. The slot 1 5A has an axis transverse to the path of travel of the bolt 19, and in this case bolt 17, since bolts 17 and 19 move in unison in the embodiment shown as described.

Thus during operation of the key 1 6 to withdraw the bolt 1 9 from its forward position, the rod 23 is constrained to move under tumbler action in the slot 15A transverse to the direction of travel of the bolt 1 9 to thus withdraw the bolt 22 out of the path of travel of the bolt 1 9 and allow the bolt 1 9 to be withdrawn to release the locking arms 11. When the key 1 6 has been rotated sufficiently to withdraw the bolt 1 9 from its locking position, the bolt 1 9 is then positioned in the path of return movement of the auxiliary bolt 22 and under spring urging, when the action of the drop lever has been removed, it bears against the bolt 1 9 in its unlocking position.

Similarly when the key 1 6 is actuated to work the bolt 1 9 to its forward and locking position, the action of the drop lever 1 5C of the tumblers bearing on the rod 23, serves to depress the auxiliary bolt 22 against the spring action of spring 24 to allow free movement of the bolt 1 9 to its locking position. In the maximum forward position of the bolt 1 9 therefore when the tumbler action has been completed, the auxiliary bolt 22 moves behind the bolt 1 9 and in its path of travel to thereby block movement to its unlocking or withdrawn position.

Thus the auxiliary bolt 22 constitutes a live relocking means which is operative during lock actuation. In other words the key 16 while performing main locking also actuates the live relocking means, the dual-action being derived from the tumblers of the lock 1 5.

While the rod 23 has been described as bearing on the drop lever, it will be appreciated that coaction with any one or more of the tumblers will suffice to achieve the required actuation of the auxiliary locking bolt 22.

Claims (7)

1. A locking mechanism comprising tumblercontrolled locking bolt means movable between an unlocking and locking position, and an auxiliary locking member constrained for movement into the path of travel of said locking bolt means to prevent movement thereof from said locking position, said locking member being actuable out of said path of travel in response to movement of one or more of the tumblers during lock operation to allow movement of the bolt means between said locking and unlocking positions.

2. A locking mechanism as claimed in Claim 1 wherein said locking bolt means comprises a first locking bolt, and a tumbler-controlled second locking bolt, said first and second locking bolts being interconnected for movement in unison, said auxiliary locking member being an auxiliary bolt having a connecting rod engaging one or more of the tumblers controlling the second locking bolt, and spring means arranged to urge said auxiliary locking bolt into the path of travel of said first locking bolt.

3. A locking mechanism as claimed in Claim 2 wherein said tumbler-controlled second locking bolt is mounted in a casing, the casing being provided with a slot having an axis transverse to the path of travel of said first locking bolt, said connecting rod engaging one or more of the tumblers through the slot such that during lock operation the path of travel of the auxiliary bolt is transverse to the path of travel of said first bolt.

4. A locking mechanism as claimed in Claim 2 or 3 wherein said first locking bolt moves into the path of return travel of said auxiliary bolt during movement to said unlocking position.

5. A locking mechanism as claimed in any one of Claims 2 to 4 wherein said first locking bolt is mounted in a cylindrical housing for mounting in a corresponding cylindrical opening of a safe, a pair of semi-circular locking arms surrounding the cylindrical housing and being pivoted together thereon, said first locking bolt being movable in the housing during lock operation to open the locking arms and effect lock closure in the opening.

6. A locking mechanism as claimed in any one of Claims 2 to 5 wherein said tumbler-controlled second locking bolt is a dead lock.

7. A locking mechanism substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.