GB2084367A - A Transportable Safe - Google Patents

Abstract

A transportable safe comprises a closed cabinet having an openable door 11 fitted with a lock mechanism 12. A housing 15 beneath the cabinet encloses a power source, an electrical, circuit and a noise generator, the circuit being connected to a door switch 21 and to three multiposition rotary switches 17 having knobs 18 associated with calibrated scales 20. The arrangement is such that the noise generator is energised on operation of switch 21 by opening the door 11 unless the rotary switches are pre-set to particular positions. Alternatively, a vibration-sensitive switch or a switch triggered by lifting the safe may be employed instead of the door switch 21. The electric circuit is arranged to latch on, to sound the noise generator for a predetermined time, once the circuit has been triggered. <IMAGE>

Description

SPECIFICATION A Transportable Safe This invention relates to a transportable safe, by which term is meant a security box which is not permanently installed at some site, but which can therefore be moved from place to place.

Both domestically and in industry and commerce of all types it is frequently required to store articles with at least a measure of security, whilst still having those articles readily accessible.

A small safe may serve the required purpose, and from the security point of view it is most advantageous for the safe to be permanently installed at some site - for instance by being let into a wall or floor, or attached to a wall or floor by fastenings which are accessible only from the interior of the safe. The installation costs of such a safe can be relatively high, and often such permanent installation may be prohibitedfor instance in the case of a rented or leased property. Because a small safe or security box can be carried from one place to another with relative ease, little security is offered thereby, and if permanent installation is not possible, it is necessary to employ such a large safe that it cannot unobtrusively and simply be moved.

Another disadvantage of many relatively small safes and security boxes is that the locks fitted thereto are not particularly secure; in view of the small size and in attempt to keep the cost of the safe or box down, the lock may not present a particularly difficult problem to pick or force.

It is a general object of this invention to provide a transportable safe which offers greater security than the known designs of security box or portable safe, as discussed above.

According to this invention, there is provided a transportable safe comprising a substantially closed cabinet having an openable door fitted with a lock to maintain the door in the closed position, first electrical switch means mounted so as to be inaccessible from the exterior of the safe when the safe is free-standing on a surface and adapted to be operated on tampering with the safe, second electrical switch means in the form of a multi-position switch having a manualiy- operable control accessible from the exterior of the safe, and an electric circuit having means to allow the connection of a power source thereto and a noise generator for operation thereby, the first and second electrical switch means being operatively connected to the electric circuit such that when a power source also is connected therero, the noise generator is energised on tampering with the safe unless the second switch means has been set to a particular predetermined position.

The first electrical switch means preferably is in the form of a vibration-sensitive switch, such that the contacts thereof will be closed (in the case of a normally-open switch) or opened (in the case of a normally-closed switch) should the safe be tampered with in any unauthorised manner for instance by attempting to force the lock or by moving the safe from one place to another. An alternative is for the first electrical switch means to be associated with the door, such that the switch means is operated on opening of the door, thereby causing the noise generator to sound unless the second switch means has been set to said particular position. Most preferably, the first switch means includes both a vibration-sensitive switch and a switch associated with the door for operation on opening thereof.In this way, security can be greatly enhanced against unauthorised attempts at opening the safe or removing it to some other location.

In addition to or instead of a vibration-sensitive switch, a trip-switch may be provided, which switch has an operating member projecting from the lowermost face of the safe whereby placing the safe on a surface operates the trip-switch to one position and lifting the safe off the surface causes the trip-switch to be operated to its other position. Such a trip-switch thus serves to increase the security of the safe by ensuring the noise generator is energised on lifting the safe, unless the second switch means is set appropriately.

The second switch means conveniently is in the form of a rotary multi-position switch having typically 10 positions selectable by means of a manually-operable knob. The knob may have a pointer which runs round a scale indicating the instantaneous setting, or turning of the knob may cause a scale to turn, the calibrations of the scale being visible one-at-a-time through a window in a housing for the switch. Another possibility is for the first switch means to be in the form of a thumb wheel, an arc of the periphery of which is accessible to effect turning thereof through an opening in the housing for the switch.

To make it yet more difficult for an unauthorised person to open the safe, it is advantageous for the second switch means to have two or more, and preferably three, separately operable multi-position switches, each of which must be set to a particular predetermined position before the noise generator will not be energised on the first switch means being operated. Each of the separate multiposition switches may take any of the configurations described above, but ail of the switches are preferably similarly configured, from the aesthetic point of view.

The electrical circuit may be arranged to cause continuous energisation of the noise generator on operation of the first switch means unless and until the second switch means is set to the particular predetermined position. An alternative is for the electrical circuit to include a timer, arranged to cause the noise generator to be energised for a particular periodfor instance, 2 minutes - if the condition of the first and second switch means is such that the generator should be energised. A further refinement is for the circuit to include a latch, which serves to keep the noise generator energised for said particular period should the condition of the first and second switch means be appropriate, and even if the second switch means is operated during sounding of the generator to the particular predetermined position.This has the effect of attracting attention to the safe, even if the person tampering therewith manages to set the second switch means appropraitely.

The transportable safe conveniently is provided with a holder for a dry-cell power source, to which the circuit can be connected. The holder should be accessible either from beneath or from the interior - either way, the power source could not then be removed without first disturbing the safe and thus without triggering the noise generator unless the second switch means is appropriately set.

A dry cell power source may be substituted by a rechargeable power source, such as a nickelcadmium battery. The safe may then include a trickle charging circuit, operable by a mains supply when connected to the safe. Conveniently, a socket would be provided on the safe to receive a plug on a flexible cable connectible to a mains outlet, such that the circuit may be operated by the mains, or by a contained rechargeable power source when the mains is not connected to the safe.

By way of example only, one specific embodiment of this invention will now be described in detail, reference being made to the accompanying drawings, in which: Figure 1 is a perspective view of a complete transportable safe constructed in accordance with this invention; Figure 2 is a further perspective view of the safe of this invention, but with the door thereof open, Figure 2A showing a detail view of part of the safe shown in Figure 2; and Figure 3 is a schematic diagram of the circuit employed in the safe shown in Figures 1 and 2.

Referring initially to Figures 1 and 2, the transportable safe of this invention comprises a main cabinet 10 generally in the form of a cube constructed from steel sheets welded together, but with a door 11 provided to close an opening in the front face of the cabinet. The door is hinged along its left-hand vertical edge to the cabinet 10 and is provided with a key-operated lock mechanism 12 adjacent its right-hand edge, to engage a latch plate (not shown) provided as a part of the main cabinet 10. The door 11 is deeply recessed, when closed, so as to render it very difficult to insert some form of prising tool, in an attempt to force open the door without first releasing the lock 12. It is preferred for the lock mechanism itself to be of the high-security type, and particularly one where the lock manufacturer only supplies keys to registered persons.

Both the main part of the cabinet 10 and the door 11 are double-skinned, the space between the two skins being filled with a material of low thermal conductivity characteristics, so that the contents of the safe are less likely to suffer damage in the event that the safe is surrounded by flames. The double-skinning of the door is however cut away in the region of the lock 12, as shown in Figure 2A, to allow the lock member 13 to project laterally of the door 11, thereby to engage the latch plate of the cabinet when the door is in the closed position and the keyoperated lock mechanism actuated.

Beneath the main cabinet 10, there is provided a housing 1 5 having louvres 1 6 formed in the sides thereof. Within the housing 1 5 there is mounted an electric circuit (shown schematically in Figure 3), a noise generator such as an electrically-operated siren, and a dry cell battery holder. The housing 1 5 is closed by a bottom plate (not shown in the drawings) having a removable section allowing access to the battery holder. On the front face 1 6 of the housing 1 5 there are mounted three rotary switches 17, each of which is operable by means of a control knob 18 having a pointer 1 9 which runs round a calibrated scale 20.Each rotary switch 1 7 may for instance be a 10-position switch, the scales 20 carrying the calibrations 0-9 inclusive corresponding to each of the 10 switch positions.

Mounted within the cabinet 10, adjacent the right-hand edge of the door opening, is a microswitch 21 having an operating lever so disposed that the lever is actuated on closing or opening movement of the door 11. The microswitch 21 is connected to the electric circuit within the housing 15, as are the rotary switches 17.

Figure 3 shows schematically the electric circuit provided within the housing 1 5. The battery held within the housing is connected across lines 24 and 25, and it can be seen that each of the switches 1 7 has all but one of its switched contacts connected to the supply common line 25, the wipers 26 of all of the rotary switches 1 7 being connected together and arranged to supply power to a timer circuit 27. It will thus be appreciated that the line 25 will be connected to the timer circuit 27 unless all three rotary switches 1 7 are set to the respective contacts thereof which are not commoned. The switches 1 7 are all of the make-before-break variety.

The timer circuit 27 includes an integrated circuit 28, of the type known in the art as a '555'.

This is connected as a monostable, arranged to give a pulse length of approximately 2 minutes, the precise pulse length being determined by a capacitor 29 (for instance, of capacity 100 of) and a preset variable resistor 30 (for instance of resistance 1 M). The monostable output pulse from the timer circuit 27 appears on line 31, and drives the coil 32 of a relay, the integrated circuit 28 being protected by diodes 33 and 34. The circuit is completed to line 24, back to the negative terminal of a held battery, through a thyristor 35, the gate electrode 36 of which is driven by a transistor 37, switches 38 and 39 being provided in the collector path of that transistor. The appropriate biassing conditions are set up for the transistor 37 by means of resistors 40, 41, and 42.Switch 38 represents the contacts of the microswitch 21 mounted within the cabinet 10 for actuation by the door 11, the switch being of the normally closed variety and mounted such that the contacts are held open when the door 11 is in the closed position. Switch 39 is constructed as a vibration-sensitive switch - for example, a spring blade clamped at one end and having at the other end a relatively heavy weight, electrical contacts being arranged to each side of the spring blade such that movement of the switch will cause the pendulum to start vibrating and thus to connect to the contacts. This switch 39 is thus at least momentarily closed on being subjected to vibration.

The armature of the relay driven by the timing circuit 27 operates contacts 44, arranged in series with a motor-driven siren (not shown) also connected across the battery power supply.

It will be appreciated that should any of the rotary switches 1 7 not be connected to an opencircuit wiped contact, power will be supplied to the timer circuit 27, ready to cause actuation thereof should either switch 38 or 39 be closed.

On closing either or both of these switches, the transistor 37 serves to trigger the thyristor 35, which then remains conducting notwithstanding subsequent opening of the two switches 38 and 39. The timer circuit 27 thus yields a pulse of duration of approximately 2 minutes, energising the coil 32 of the relay which in turn closes contacts 45 to cause the siren to sound. The siren can only then be switched off by appropriate setting of all three rotary switches 1 7 (in this case to the code 4-8-1) and if this code is not set, the siren will continue to sound for the full period of the monostable pulse.

In a typical embodiment of the invention as described above, the cabinet 10 is a cube the sides of which measure approximately 300 mm.

The safe is thus relatively easily transportable and inconspicuous, and yet well-protected when the door 11 is shut and the lock 12 operated, simply by setting the rotary switches 1 7 to some combination other than the particular combination which prevents the supply of electricity from the battery to the timer circuit 27.

However, when it is required to open the safe, all that is necessary is to set the required combination on the three rotary switches 17, whereafter a key may be used in the lock 12 in the usual way to open the door 11, without the siren sounding.

Claims (12)

Claims (Filed on 17 September 1981)

1. A transportable safe comprising a substantially closed cabinet having an openable door fitted with a lock to maintain the door in the closed position, first electrical switch means mounted so as to be inaccessible from the exterior of the safe when the safe is free-standing closed on a surface and adapted to be operated on tampering with the safe, second electrical switch means in the form of a multi-position switch having a manually-operable control accessible from the exterior of the safe, and an electric circuit having means to allow the connection of a power source thereto and a noise generator for operation thereby, the first and second electrical switch means being operatively connected to the electric circuit such that when a power source also is connected thereto, the noise generator is energised on tampering with the safe unless the second switch means has been set to a particular pre-determined position.

2. A transportable safe according to claim 1, wherein the first electrical switch means is in the form of a vibration-sensitive switch.

3. A transportable safe according to claim 1 or claim 2, wherein the first electrical switch means includes a switch element associated with the door, such that the switch means is operated on opening of the door.

4. A transportable safe according to any of the preceding claims, wherein there is provided a tripswitch which has an operating member projecting from the lowermost face of the safe whereby placing the safe on a surface operates the tripswitch to one position and lifting the safe off the surface causes the trip-switch to be operated to its other position, the trip-switch being connected to the electric circuit for energisation of the noise generator when the trip-switch is in its other position unless the second switch means is appropriately set.

5. A transportable safe according to any of the preceding claims, wherein the second switch means comprises a rotary multi-position switch any one of which may manually be selected.

6. A transportable safe according to claim 5, wherein there is a pointer associated with the second switch means which pointer runs over a scale indicating the instantaneous switch setting.

7. A transportable safe according to claim 5 or claim 6, wherein the second switch means has two or more separately operable multi-position switches, each of which must be set to a particular pre-determined position to inhibit energisation of the noise generator on operation of the first switch means.

8. A transportable safe according to any of the preceding claims, wherein the electrical circuit is arranged to cause energisation of the noise generator on operation of the first switch means unless and until the second switch means is set to the particular predetermined position for a predetermined period.

9. A transportable safe according to claim 8, wherein the circuit includes a latch which serves to keep the noise generator energised for said period once triggered.

10. A transportable safe according to any of the preceding claims, wherein there is provided a holder for a dry-cell or re-chargeable power source to which the circuit can be connected.

11. A transportable safe according to claim 1 0, wherein the power source holder is accessible only from one of beneath the safe or the interior.

12. A transportable safe substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.