Field of invention

The present invention relates to a lock, and particu- larly, but not exclusively, to a safe lock of the kind comprising a bolt which projects partially from a lock housing and which is movable between an open position and a locking position and on which there is stacked a plurality of movable levers which in the locking mode of the lock prevent axial movement of the bolt but which when manipulated by a key which fits the lock are moved to positions in which the bolt can be moved axially.

Locks of this kind are widely used with safes or simi¬ lar safety deposit cabinets, although such locks are also used in many other instances. When the lock is used as a safe lock, the bolt is not incorporated directly in a striking-plate, but co-acts with a εuit- ably configured cre one construction which, with the assistance of strong locking members, renders forcing of the safe difficult.

Background art In the case of hitherto known locks, the levers are often held in their locking positions by means of springs. This does not afford a fully satisfactory solution, however.

For instance, a person wishing to force the lock is able to cause the levers to stick together so that the springs will be unable to move the mutually joined levers to their locking position, for instance with the aid of chewing gum or by injecting an emulsion agent into the lock, or in some other way. The lock can then

be opened with comparative ease, without the use of a key, by simply inserting a suitable tool into the lock, or in some other way. Examples of known locks of this kind are described and illustrated in SU,A, 1 227 784 (Simf Glavstanteknpr), US,A,2 750 787 (Soler Capdevila) and CH,B,527 998 (Cisa).

GB,A,2 081 796 (Durose) describes a lock of the kind defined in Claim l, in which the levers are not acted upon or biased by springs. One and the same device biases all levers towards an acceptance pin, and this lock can therefore also be forced with relative ease. This lock cannot be reset with the aid of key other than that for which the lock has been turned to its locking mode.

Object of the invention

One object of the invention is to provide a lock, particularly a safe lock of the aforedescribed kind, which is far more difficult to force than conventional locks of this kind.

Another object is to provide a lock of the aforedescri¬ bed kind which will enable separate levers to be actua- ted individually when locking the lock, despite the absence of readily manipulated spring elements.

A further object of one embodiment of the invention is to provide a safe lock with which the lock mechanism code can be reset with the use of an alternative key to the key belonging to the lock, and which, subsequent to being locked by the alternative key, is equally as difficult to force as prior to changing the key and code.

Disclosure of the invention

These and other objects are fulfilled with an inventive lock of the kind defined in the preamble of Claim 1 and having the characterizing features set forth in the characterizing clause of said claim.

The positively controlled movement of said movable device ensures that the key cannot be removed from the lock before the device is in position, and also that said device is unable to take a correct locking posi¬ tion unless all levers are located in their intended positions.

Thus, in an attempt to force the lock it is impossible to manipulate the levers with the aid, for instance, of chewing gum or some other substance for the purpose of overcoming any spring force which biases the levers towards the locking position. Instead, the person attempting to force the lock must first release the device from its positively guided locking position, and thereafter manipulate each lever separately so that all levers will be located in a release position, which is a practically impossible task.

Thus, forcing of an inventive lock is much more diffi¬ cult than forcing of conventional locks.

Furthermore, the individual actuation of separate levers in accordance with the invention enables the levers to be reset with the aid of a key other than that with which the lock has been locked. For instance, if the original key is stolen this resetting of the levers will mean that the lock can no longer be opened with the stolen key.

The levers can thus be said to exhibit a "floating arrangement" and the device engaging against the levers is able to actuate separate levers differently in relation to one another.

The characteristic features set forth in Claim 2 con¬ tribute to this lock facility.

In practice, it is preferred that the inventive lock has the characteristic features set forth in Claim 3. In this case, the blade-like members have a configura¬ tion which corresponds to the tapering shape of the levers towards their respective ends. The alternate engagement with the levers will ensure that the posi- tively guided movement of the device in a direction towards said levers will result in reliable engagement therewith.

The lock will preferably include a lever which is configured differently to the remaining levers and which is preferably located nearest the bolt and which is pivoted to the locking position in the final phase of turning the key. A coupling member passed through the device between said separate levers and said device will therewith preferably cause axial movement of said device.

This coupling member suitably comprises a pin which is accommodated in a groove or slot formed in the lever of different configuration and extending angularly in relation to the direction of bolt movement, said pin also entering a hole provided in said device.

A comparatively small pivotal movement of the lever of different configuration, hereinafter referred to as the

"special lever" can, in this way, be given a compara¬ tively powerful transmission, said pivotal movement suitably being produced by direct key action. The special lever moves pivotally substantially transverse- ly to the longitudinal axis of the lever and, with the aid of the aforesaid coupling member, ensures that the device will move essentially rectilinearly at right angles thereto, i.e. in a direction opposite to the direction of the bolt when moving to the locking posi- tion.

An inventive lock mechanism finds particularly advanta¬ geous use in a lock of the kind in which the levers in the open position of the lock bolt and subsequent to inserting a key of deviating code profile are intended, when the key is turned, to take new positions which adapt the lock mechanism to this key and therewith prevent the bolt from being moved axially with some other key, e.g. the key which earlier fitted the lock.

Locks of this kind are particularly advantageous, since if a key is stolen or lost in some other way the lock code can be readily reset, simply by inserting and turning a key whose code deviates from the code of the earlier key, with the lock in an unlocked state.

This must be done, however, when the lock is unlocked, which assumes that one has access to another key of the same kind as that which was lost, in order to be able to open the lock prior to resetting the lock code.

The inventive lock mechanism can be used to particular advantage with this type of lever lock if, in accor¬ dance with a further development of the invention, a latching means which can be actuated from outside the

lock housing is constructed to prevent, in its latching position, rotation of the key to a position in which the key can be removed through the key slot of the lock housing when the bolt is in its unlocking position, and which latching means, subsequent to being moved to its unlocking position or release position, will permit the key to be withdrawn and the said other key of deviating code profile to be inserted into the lock with the intention of resetting the levers and adapting the levers to the new key code, said levers being moved to locking positions subsequent to turning the key and moving the bolt to its lock locking position, and being held in their reset positions by said means when the new key is removed from the lock.

The latching means can thus be actuated from outside the lock housing, which requires the lock to be opened, e.g., with the aid of a reserve key. This key, however, cannot be removed from the key slot until the latching means has been moved to its release position, which can be readily achieved by finger action. A key of devia¬ ting code profile can then be inserted into the lock and turned so as to reset the levers automatically and adapt the levers to this new code profile. At the same time, the lock is moved towards its locking position and the levers adopt their locking positions at the end of this bolt movement.

At the same time, the special lever is actuated by the key-bit in the aforedescribed manner, said special lever being excluded from the aforedescribed resetting operation, so that the lever is rotated transversely to the longitudinal axis of the other levers and therewith ensures that the device moves towards the levers and holds said levers reliably in their adopted locking

positions. The new key can then be removed from the lock. It is now impossible to open or manipulate the lock mechanism without access to this key or to a corresponding key.

According to one preferred embodiment, the latching means is intended to return automatically to its latch¬ ing position when the bolt moves in a direction towards its locking position.

This is readily achieved, by providing the bolt with a recess configured to conform to the latching means and permitting displacement of the latching means in the release position of the bolt, but which when the bolt is moved to its locking position engages the latching means and carries said means with the bolt movement.

The aforedescribed simple process of resetting the lock code is made possible because each lever is provided in the region of its end remote from the acceptance recess with a slot which extends transversely to the levers and through which there extends a pin which passes through an elongated hole in the lock bolt and which is connected to the lock housing. The pin has provided on one end thereof a segment which presents a plurality of teeth which when the lock mechanism is reset to a new key code permit alternative coaction with a pin mounted in the bolt slide and having an engagement part which fits in the space between mutually adjacent teeth.

The special lever, however, has no such teeth and is pivotally mounted on the pin, via a round hole, and does not take part generally in the re-setting move¬ ments of the levers for adjustment to the new key-code profile.

According to one preferred embodiment, the positively guided, movable device has the form of an insert provided with a semi-circular recess for pins which guide the sliding bolt, the radius of this recess being greater than the radius of the pins and the insert presenting a central recess for accommodating an accep¬ tance pin joined to the bolt slide.

The inventive lock may also be provided with other types of positively guided, movable devices for holding the levers in the locking position.

Other characteristics of the inventive lock, and advan- tages afforded thereby, will be evident from the fol¬ lowing description of a preferred embodiment of the invention. The description is made with reference to the accompanying drawings.

Brief description of the drawings

Figure l is a perspective view of a safe lock which is intended for coaction with a cremone construction on the inside of a door, part of which has been cut-away.

Figure 2 is a perspective view of the lock mechanism which is shown in its locking mode in a lock housing, part of which is not shown.

Figure 3 is an exploded view of the components of said lock mechanism, wherein only one of eight corresponding levers is shown, together with the special lever loca¬ ted nearest the lock slide.

Figure 4 is a top view of the lock mechanism shown in Figure 2 subsequent to having removed all eight mutual-

ly identical levers, and with the sliding bolt being moved in a direction towards its locking position under the action of a lock key.

Figure 5 is a top view corresponding to Figure 4 and illustrates the lock mechanism subsequent to further rotation of the key for actuation of the special lever, and therewith positively guided movement of an insert in a direction towards the levers, said insert forming part of the lock mechanism.

Figure 6 is a top view which illustrates part of the lock mechanism shown in Figures 4 and 5 subsequent to rotating the key clockwise so as to move the bolt to its unlocking or release position, removal of the key from the lock being prevented by a latching means.

Figure 7 is a view corresponding to Figure 6 subsequent to finger-actuation of the latching means and movement of the key to a position in which the key can be remo¬ ved and replaced with another key of deviating code profile, so as to reset the locking mechanism and adapt said mechanism to the code of the new key.

Description of preferred embodiments

With reference to Figures 1-3, a safe lock mounted on a door 1 comprises a lock housing 2 and a lock mechanism 3 housed therein.

The lock housing 2 has a front side wall 2a in which there is provided a key slot 2b, and a rear side wall 2c on which there are mounted four cylindrical guides for a sliding bolt 5.

The cylindrical guides 2d determine the thickness of the lock housing and function as supports for the front wall 2a of the lock. The rear side wall 2c also carries a central pin 2e for coaction with a key 6 and a latch means 2f which can be actuated by the fingers of one hand from outside the lock housing. Also mounted on the rear side wall 2c is a guide pin 2g for supporting eight mutually stacked levers 10, of which only one is shown in Figure 3.

Figure 2 shows the lock mechanism 3 in its locking mode. Figure 2 illustrates the eight levers 10, stacked one upon the other, with the undermost lever lying in abutment with an especially configured lever 11, also shown in Figure 3, this lever being referred to herein¬ after as the "special lever".

As illustrated in Figure 3, each lever 10 has a central key aperture 10a, a transversely extending aperture 10b located at one end of said lever and intended for accommodating the guide pin 2g, a fishtail-shaped recess 10c located at the other end of the lever and provided with two shoulders lOd which function to hold the so-called acceptance pin 5c on the bolt 5 in the locked state of the lock.

The bolt 5 has a central aperture 5a which exhibits a "nose-shaped" part 5b in which the key-bit engages so as to move the bolt between its locking and unlocking position respectively, depending on the direction of key rotation.

The central aperture also has a part 5c which when the bolt occupies its unlocking or release position enables the finger-actuable latching means 2f to be moved in ^*

the side wall 2c and upon movement of the bolt to the locking position entrains the latching means if this is moved to the unlocking or release position.

The bolt 5 also carries a pin 5d having an engagement part 5e which is adapted for engagement in the spaces between teeth lOf disposed on one end of respective levers 10.

The special lever 11 has a key aperture 11a provided with a separate part lla' whose function will be described in more detail herebelow with reference to Figures 4 and 5. The special lever also has a recess lie for accommodation of the acceptance pin 5c, this recess having substantially a fishtail-shape although with a hooked part lie' in the region of its widened end.

The special lever is also provided with two upper shoulders lid for coaction with the acceptance pin 5c.

Distinct from the levers 10, the special lever 11 has an asymmetric shape and exhibits on one side of the fishtail-shaped aperture lie an extended part llf which is configured with an obliquely extending slot llg. Passing through the slot llg is a coupling member in the form of a pin 12 by means of which the special lever 11 is so connected with an insert 13 that the insert 13 effects movement which is positively guided by the special lever 11.

The insert 13 is illustrated more clearly in Figures 2 and 3. The general function of the insert is to coact with the levers in a manner which will ensure that said levers occupy their locking position prior to the key

being removed from the lock and thereafter held in this position.

The insert 13 can be described generally as being composed of a plurality of blade members which are mutually joined centrally and the configuration of which is such that the insert can be said to resemble a "pair of trousers" having a " waist part" 13a and two downwardly and outwardly extending "legs" 13b. The leg parts 13b have the same thickness as the levers 10 and overlap ?, and each of said leg parts is intended, in an active position, to coact with the downardly narrow¬ ing upper part of a lever 10.

When the insert moves downwards in Figure 3, i.e. in a direction opposite to movement of the bolt 5 into its locking position, the levers are pivoted around the pin 2e, i.e. so that the acceptance pin 5c will take its position on a shoulder lOd in respective levers and the shoulder lid in the special lever 11, in which posi¬ tions the locking mechanism is locked.

Movement of the insert 13 in said direction, i.e. towards the key 6, is caused by pivotal movement of the special lever 11 in a counterwise direction in Figure 3, under the influence of the pin 12, the end of which is accommodated in the slot llg in the special lever 11.

As will be seen in Figure 3, the pin 12 is passed through hole 13c in the insert 13. The pin 12 functions as a coupling device and ensures that the insert 13 will move downwards, as seen in Figure 3, when the special lever 11 is turned in an anticlockwise direc- tion.

This is illustrated in Figures 4 and 5. Figure 4 illustrates the key 6 and key-bit 6a in the final stage of movement of the bolt 5 towards its locking position through key actuation. The acceptance pin 5c is there¬ with located opposite the fishtail-shaped groove lie. When the key-bit is turned to the position illustrated in Figure 5, the key-bit 6a engages a wall which deli¬ mits the "nose-shaped" recess part 11a' of the special lever. The special lever is therewith swung around the pin 2g, such that the acceptance pin 5c engages one of the two shoulder abutments lid. As the special lever pivots, the pin 12 is urged obliquely downwardly and to the right in the slot or groove llg, wherewith the insert 13 connected to the pin 12 is caused to execute positively guided movement in a direction towards the key, wherein the special lever 11, and the remaining levers 10 (not shown in Figures 4 and 5) are caused take their respective locking positions, through the action of the insert 13, in which they are held even when the key 6 is removed from the lock.

As beforementioned, the thickness of each blade member 13b corresponds to the thickness of respective levers and the blade members overlap one another. Thus, the blade members of said insert engage respective levers from different directions, such that all levers are held fixed in their respective locking positions.

When the key 6 is again inserted into the lock and turned clockwise with the intention of unlocking the lock, the insert 13 will initially execute a positive¬ ly-guided movement in the opposite direction, i.e. in a direction away from the levers, therewith releasing the levers from the insert. Under the action of the respec-

tive projections on the key-bit, the levers are there¬ after moved into their release positions with the fishtail-shaped grooves or slots 10c in line with the acceptance pin 5c, so that when the key is turned further in a clockwise direction and the bolt 5 there¬ with moved to its unlocking position, the acceptance pin is able to pass freely into the fishtail-shaped slots or grooves, to the position shown in Figure 6.

In this position, the latching means 2f prevents fur¬ ther movement of the key therewith preventing the key from being removed from the key hole slot 2b illustra¬ ted in Figure 1. This means that when the lock is in its unlocked mode the key cannot normally be removed from the lock until the latching means 2f has been actuated. Actuation of the latching means is effected with the fingers of one hand from outside the lock housing. Figure 7 shows the latching means 2f in its lock release position. With the latching means in this position, the key 6 can be turned so as to enable it to be removed through the key hole slot.

If the key of a safe lock should be stolen or lost in some other way, it is possible to recode the lock with the aid of another key, when the lock is in the un¬ locked mode shown in Figure 7. This other key is in¬ serted into the lock with the lock components in the positions shown in Figure 7, i.e. with the latching means 2f in its lock release position, and turned anti- clockwise. The levers 10 will therewith be manipulated by the bit of the new key and moved to a different code position, said levers moving relatively to the pin 2g which passes through the transverse recess 10b of respective levers. Towards the end of this resetting movement, during which the bolt 5 will also move to-

wards its locking position, the engagement part 5e of the pin 5d will engage in a recess between the teeth lOf, therewith fixating the new code position of res¬ pective levers.

As will be seen from Figure 3, the special lever lacks an elongated hole corresponding to the elongated holes 10b in the remaining levers. Instead, the pin 2g passes through a round hole lib in the special lever 11. Consequently, the special lever will not be reset in a manner corresponding to the resetting of the remaining levers 10.

Towards the end of key rotation in a clockwise direc- tion, the bolt and the special lever will occupy the aforedescribed positions illustrated in Figure 4, although the mutually overlapping levers 10 will have different positions due to code resetting. Further rotation of the key will cause the special lever 11 to be moved to the locking position illustrated in Figure

5, which also applies to all other levers. The insert 13 is contributory in this respect and, in the afore¬ described manner, is positively guided into engagement with all levers and therewith ensures that said levers will be moved to their locking positions and held therein.

It will be evident from the aforegoing that the lock mechanism can be readily adapted to a new key having another key code.

This fact can be utilized in practice, by delivering the lock mechanism in the state illustrated in Figure

6, i.e. a state in which the lock mechanism is in its released state and the door open and with a key which

fits the lock inserted therein. Also delivered with the lock mechanism is a number of further keys with varying codes and the user himself will decide which of these keys to use. As will be understood, the user is able to change the lock code at predetermined time intervals, so that should someone "appropriate" the key and copy the same for later use, the key can nevertheless not be used because the lock code has been changed, so that the appropriated key will not fit the lock.

At the same time as the code variation can be changed, with all of the advantages afforded thereby, the inven¬ tive principle can be applied to its full extent irres¬ pective of the key code used in each individual case. As will have been understood from the aforegoing, the special lever is namely configured so that it is not actuated when the code is reset. At the same time, the special lever, with the aid of the insert, ensures that when the bolt is moved to the locking position, by positively-guided movement of the insert, the levers will be caused to take their respective locking posi¬ tions and are held in these positions by the insert, even subsequent to removing the key from the lock.