GB2144482A

GB2144482A - A safe door locking unit

Info

Publication number: GB2144482A
Application number: GB8417180A
Authority: GB
Inventors: Henry Hugh Hamber
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-07-11
Filing date: 1984-07-05
Publication date: 1985-03-06
Also published as: GB8318760D0; GB8417180D0

Abstract

A locking plate 6 is rotatable about a shaft P and is provided with peripheral slots 9 engageable by pins 12 of respective bolts 10. The slots 9 have an arcuate first portion 9' centred on the shaft P which thus extends at right angles to the direction of movement of the bolts 10, so preventing an inwards force on the bolts 10 causing the plate 6 to rotate and allow withdrawal of all the bolts from their locking position. Locking means are provided to effect rotation of the plate 6 and preventing such rotation when the locking means of locked. This locking means may include a conventional locking bolt carrying a pin which engages a slot in the locking plate to cause rotation of the plate on extension of the bolt, or a lockable control knob may be provided to cause rotation of the plate 6. The casing is preferably square in section, a bolt being provided on each side of the square.

Description

SPECIFICATION A safe door locking unit FIELD OF THE INVENTION The present invention relates to a door locking unit for a safe particularly a floor safe.

BACKGROUND ART In the design of a door locking unit for a floor safe, it is of course imperative that major consideration be given to ensuring that the final construction has the most fool-proof locking action as is possible, and which affords the highest resistance to attack by force or explosives.

SUMMARY OF THE INVENTION It is an object of the invention to provide a door locking unit for a floor safe having the above attributes, while at the same time being easy to install in position in a safe access for locking purposes.

According to the invention there is provided a door locking unit for a floor safe comprising a casing adapted to rest in the access of a safe to be closed, a locking plate rotatably mounted in the casing, a bolt movably mounted on the periphery of the casing, a pin on the bolt engaging a slot formed in the periphery of the plate remote from its central rotatable axis, and in which the pin can move during rotation of the locking plate, and locking means for rotating the locking plate to effect movement of the bolt from a retracted unlocked position and an extended locked position by the action of the pin moving in the slot, the slot having a slot portion which the pin occupies in the locked position of the bolt, the axis of which slot portion in said locked position lies transverse or substantially transverse to the direction of movement of the bolt.

In this arrangement the interaction between the pin of the bolt and the said slot portion of the slot in the locked position, resists attempts to force the bolt to the unlocked position by tampering and such unauthorised means, thus providing the door unit with the required locking security.

The construction of the locking unit moreover is both simple and uncomplicated, and the locking action easy to execute simply by rotation of the locking plate.

In a preferred construction the casing is square in section, with a said bolt acting from each side of the casing to effect closure in a safe access.

The locking plate in this preferred arrangement is provided with a said slot at spaced intervals around its periphery, with a pin on each of the bolts engaging a respective one of the slots to effect the required actuation of the bolts during rotation of the locking plate.

The locking means of the door locking unit may advantageously be in the form of a simple key lock mounted to the housing, the bolt of which is provided with a pin engaging another slot in the locking plate, the mutual arrangement of the axis of this further slot relative to the direction of movement of the bolt, being such that the action of the pin on the bolt of the key lock, moving in the further slot, causes the plate to rotate.

Other features and advantages of the present invention will be described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of a door locking unit for a floor safe according to an embodiment of the invention; and Figure 2 is an underneath plan view of the unit of Fig. 1 generally along the line ll-ll of Fig. 1, with the cover plate for the internal workings of the unit removed.

BEST MODES OF CARRYING OUT THE IN VENTION The door locking unit shown in the drawings comprises a casing 1 which is square in cross-section, having an upper section 2 of greater square cross-sectional area, providing a peripheral shoulder 3 for resting on a counter shoulder 4 of a safe access 5 A generally circular flat locking or camming plate 6 is rotatably mounted within the casing 1 between a pair of support bosses or bushings B held to a mounting plate M by means of a bolt P, the mounting plate M being secured to a mild steel plate R within the casing 1.

The mild steel plate R abuts an upper hardened protective steel plate S and both extend over the top internal surface of the casing 1, the plate R being seen in Fig. 2.

The size of the locking plate 6 is such that its peripheral edge lies close to the central area of each of the internal sides of the casing 1.

The locking plate 6 is provided with four equispaced slots 9 located near the periphery of the plate 6. Each slot 9 has a first portion 9 which is arcuate and centred on the bolt P about which the locking plate 6 pivots; the second portion 9'8 is inclined to the first portion so that the end of the second portion 9" remote from the junction with the portion 9' is closer to the pivotal axis of the plate 6 than the end adjoining the first portion 9'.

A bolt 10 is mounted for sliding movement in an opening 11 located at the centre of each of the internal sides of the casing 1. Each bolt 10 has a wide outer portion and a narrower inner portion, thus forming a shoulder 10a between these portions. A pin 1 2 extends from the inner portion of the bolt 10 through the slot 9.

A key lock 1 3 is secured to the mild steel plate R and an access A is provided through the upper section 2 of the casing 1 and all the intervening plates for a key to operate the lock 1 3. Suitable types of locking means could be employed as will be appreciated by those skilled in the art. The lock 1 3 moves a pin 1 5 along a slot 1 6 in the plate 6, the stroke of the pin 1 5 and the direction of the slot 1 6 being so inclined that movement of the pin 1 5 along the slot 1 6 causes the plate 6 to rotate. As the plate rotates, the pin 1 2 on each bolt 10 moves along the slot 9.As the pin 1 2 moves along the slot portion 9", the bolt 10 is caused to move radially of the plate 6. The bolt 10 is fully extended when the pin 1 2 reaches the junction between the two portions 9' and 9", and as the plate 6 continues to rotate, the pin 1 2 moves along the slot portion 9' and any reverse pressure applied to the bolt 10 cannot force the plate 6 to rotate and allow the bolt 10 to be withdrawn because the slot portion 9' is at right angles to the direction of movement of the bolt 10. As the bolt 10 is withdrawn, the shoulder 1 Oa approaches the periphery of the plate 6 which is provided with a cut out portion 7 for each bolt to receive the shoulder 1 Oa as the pin 1 2 moves along the slot portion 9".As can be seen from Fig. 1, the shoulder 1 Oa shields the region where the pin 12 enters the slot 9 to prevent tampering.

It will be seen that the peripheral edge of the locking plate is located close to the walls of the casing so that the full mass of the plate 6 is utilised to provide robustness to the locking unit.

A dead re-locking device is provided to foil attempts to force entry. A bar 1 7 is held centrally of the casing 1 by the bolt P (not shown in Fig. 1). Each end 17' of the bar 17 is provided with spaded members (not shown) which releasably engage the end of a plunger 1 8 designed to enter a recess 19 in both of an opposite pair of the bolts 10. The plungers 1 8 are urged to the recesses 1 9 by springs T, each spring T being normally held in tension by the ends 17' of the bar 17. If the door locking unit is attacked so that the plate 10 is depressed, the ends 17' of the bar 1 7 release the plungers 18 and allow them to enter the recesses 19, thus preventing the bolts 10 from being withdrawn.

The door locking unit as described is completed by being provided with a pivotal handle H mounted on the upper section 2 of the casing 1, and a cover plate C over an opening 21 in the lower end of the casing 1.

An example of another suitable type of locking means is a control knob mounted on the upper section 2 of the casing 1 which can be rotated about an axis and is provided with the pin 1 5 described above mounted eccentrically of the knob. A separate lock is provided to prevent rotation of the knob when the bolts are in their extended position.

It will be noted that the shoulder 1 Oa is close to the periphery of the plate 6. Even if the pin 1 2 should become bent or broken, each bolt 10 can only be forced inwards a short distance before the shoulder 1 Oa engages the periphery of the plate 6, thus preventing the full withdrawal of bolts 10 except by rotation of the plate 6 in the normal manner.

Claims

1. A door locking unit for a floor safe comprising a casing adapted to rest in the access of a safe to be closed, a locking plate rotatably mounted to the casing, a bolt movably mounted on the periphery of the plate remote from its central rotatable axis, and in which the pin can move during rotation of the locking plate, and locking means for rotating the locking plate to effect movement of the bolt from a retracted unlocked position and an extended locked position by the action of the pin moving in the slot, the slot having a slot portion which the pin occupies in the locked position of the bolt, the axis of which slot portion in said locked position lies transverse or substantially transverse in the direction of movement of the bolt.

2. A door locking unit as claimed in Claim 1 wherein the casing is square in section, a said bolt acting from each side of the casing to effect closure in a safe access, said locking plate being provided with a said slot at spaced intervals around its periphery with a pin on each of the bolts engaging a respective one of said slots to effect actuation of the bolts during rotation of the locking plate.

3. A door locking unit as claimed in Claim 1 or 2 wherein the locking means is in the form of a key lock, the bolt of said key lock carrying a pin which engages a further slot in said locking plate, the further slot being arranged in relation to the linear movements of the pin on the bolt of the key lock, such that actuation of the key lock rotates the locking plate.

4. A door locking unit as claimed in Claim 1 or Claim 2 wherein the locking means comprises a rotatable control knob provided with an eccentrically mounted pin which engages a further slot in said locking plate, the further slot being arranged in relation to the movements of the pin on rotation of the control knob, such that rotation of the control knob rotates the locking plate, the locking means further comprising means for preventing rotation of the control knob in the locked position of the bolt.

5. A door locking unit substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.