Especially doors are locked to a great extent by means of latch locks that are opened from the outside by means of a key and from the inside by turning a catch on the lock. However, this device has the disadvantage that a thief who e. g. entered by breaking up a window or breaking a glass pane can unlock the lock easily and effortlessly and escape with even large stolen goods through a door to the open.

The Danish Crime Prevention Council therefore recommends the use of locks that only can be unlocked by means of a key from both sides. However in case of fire the serious situation might arise that the keys cannot be found in the hurry or are inaccessible because they e. g. are in a place that is on fire.

Thereby, persons behind a locked door risk dying in the flames because they are unable to open the door. The same is the case if children are home alone and the parents have locked the door from the outside without giving the children a key to unlock the lock from the inside.

In buildings with separate premises, for example apartments or offices in an office block, it is common that each of the premises has a lock with a separate key. A doorman or caretaker then has a master key which, if necessary, will enable him to obtain access to all premises in the building.

In cases of the building having many premises it can however be difficult to keep check of the many different keys that sometimes are lost or copied illegally.

The above disadvantages of the known key locks can be avoided if a combination lock is used instead that in a known way can be mechanically, electrically or magnetically operated or operated by a card with a code.

From the French Patent No. 2 686 115 is known a latch lock that is operated by means of a combination lock in replacement of the handles on the pin for activating the bolt. For this purpose is used a relatively complex and expensive push-button combination lock which can be unlocked from the inside by means of a catch and which therefore does not offer the wanted optimal protection against burglary.

In one aspect of the invention a combination lock of the kind mentioned in the opening paragraph is provided that has a simple and inexpensive design.

In a second aspect of the invention a combination lock of the kind mentioned in the opening paragraph is provided that can be mounted easily and quickly at the place of use.

In a third aspect of the invention a combination lock of the kind mentioned in the opening paragraph is provided that can be mounted on the inside of a door to supplement a latch lock which can be unlocked from the outside by means of a key and from the inside by means of a catch.

In a fourth aspect of the invention a combination lock of the kind mentioned in the opening paragraph is provided that can be activated by a lock from both sides of e. g. a door.

In a fifth aspect of the invention a combination lock of the kind mentioned in the opening paragraph is provided that can be used in connection with a cremone bolt.

According to the invention the combination lock comprises a bolt extending displaceably through the locking case, and a coupling functioning between the bolt and sliding bolt for making the two parts displace themselves simultaneously on activation of the combination lock whereby the combination lock obtains a simple, inexpensive and at the same time effectively functioning design.

The combination lock can be arranged to be operated from only one side. This embodiment is especially suited for windows or in supplement of a door lock having an inside catch. As independent lock for e. g. a door, the combination lock can be arranged for operation from both sides of the door.

With a view to obtain an easy, quick and safe mounting in e. g. a door, the locking case can, according to the invention, be completely or partly recessed in the door, and in this case a guiding tube can furthermore be recessed that is extending through opposite cross openings in the locking case for displaceably receiving the bolt. The locking case is secured in a simple manner in the door by means of the guiding tube without use of screws or fittings.

In a simple and inexpensive embodiment the coupling can comprise one or more links which are journaled in the sliding bolt at one end and in the bolt at the other end and are forming an angle with both the axis of the sliding bolt and the axis of the at least one bolt in all the possible axial positions of the sliding bolt. This embodiment is especially suited for locking windows.

In a second embodiment the coupling can comprise a gear segment which is constructed with an abutment abutting the inside end of the sliding bolt in the locked or unlocked state of the combination lock whereas the bolt then is constructed as a toothed bar engaging with the gear segment. This embodiment is especially suited for a door that is only to be locked from e. g. the inside or optionally can be locked from both sides.

The invention is explained in greater details below, describing only exemplary embodiments with reference to the drawing, in which Fig. 1 is an axial sectional view of a first embodiment of a combination lock according to the invention in locked state, Fig. 2 is the lock in fig. 1 in unlocked state, Fig. 3 is a sectional view taken along the line III-III of fig. 1, Fig. 4 is an axial sectional view of a second embodiment of a combination lock according to the invention, Fig. 5 is the lock in fig. 4 in unlocked state, Fig. 6 is an axial sectional view of a third embodiment of a combination lock according to the invention, Fig. 7 is the lock in fig. 6 in unlocked state, Fig. 8 is an axial sectional view of a fourth embodiment of a combination lock according to the invention, Fig. 9 is the lock in fig. 8 in unlocked state, Fig. 10 is a sectional view of a fifth embodiment of a combination lock according to the invention, Fig. 11 is the lock in fig. 10 in unlocked state.

Figs. 1 and 2 show a first embodiment of the combination lock used for locking an only fractionally shown door 1 in an only fractionally shown door case 2.

The combination lock comprises a locking case 3 recessed in the door and a guiding tube 4 also recessed in the door and extending through opposite cross openings 5 in the locking case 3 and out to the door edge 6 that is situated opposite the door case 2 when the door 1 is closed.

Thus as it is the guiding tube that is securing the locking case securely and solidly in place in the door, the combination lock can be mounted quickly and easily without use of e. g. screws and fittings by quite simply boring holes for the locking case and the guiding tube respectively in the door and placing these parts in their respective holes.

In the locking case there are mounted rotatably-in this case - three code discs 7 that are kept at mutual distances by spacer rings 8 and each are constructed with a central opening 9 and a dowel 10 extending into this opening. Each code disc is furthermore provided with at least one catch pin 11 facing the neighbouring code disc. By turning the two code discs in relation to each other, their catch pins can be made to engage each other.

A sliding bolt 12 having a head 13 and a base 14 is extending through the central openings 9 of the code discs. In the sliding bolt 12 a number of circumferential grooves 15 and a longitudinal key slot are made. The base is fastened to the sliding bolt by means of a screw (not shown).

A tubular actuator 18 rotatably mounted in the locking case is extending out of this case into the open. The actuator consists of an inner and outer part 19,20 that are joined by screws 21 around an inwardly facing collar 22 on the case whereby the actuator is secured axially in relation to the case. The actuator can by means of a second catch pin 23 be connected rotatably to the nearest of the three code discs 7.

Along the periphery, the outer part 20 of the actuator is provided with a dial (not shown). A mark, for example a line (not shown), is located in a visible place of the part of the case that is extending out of the door.

The catch pins 11 and 23 are located in such a way in relation to the dowels 10 that these dowels are made to be aligned in the key slot of the sliding bolt when the actuator is successively turned in relation to the mark on the locking case to ciphers, which on the dial correspond to a specific code, whereby the sliding bolt now freely can be pushed back and forth in the case.

A gear segment 24 journaled in the locking case by a shaft 25 is engaging with a bolt 26 made as a toothed bar with circumferential teeth 27 and located displaceably in the guiding tube 4. The gear segment 24 has at the bottom-seen in the figure-an abutment 28 engaging with the base 14 of the sliding bolt.

A spacer ring 29 having an inwardly facing collar 30 is keeping the code discs 7, the spacer rings 8 and the inner part 19 of the actuator 18 in place in the locking case 3. The inwardly facing collar 30 is functioning as stop to the sliding bolt 12 in the outer position of this bolt.

As shown in fig. 3, the gear segment 24 is designed as a section of a disc. On either side of this disc is mounted a prestressed helical spring 31 for keeping the gear segment in engagement with the base of the sliding bolt (see also figs. 1 and 2).

In the door case 2 is also located a strike plate 32 in form of a short pipe.

After the successive turning of the actuator to the ciphers corresponding to the code of the combination lock, the sliding bolt can, as mentioned earlier, be displaced freely back and forth in relation to the locking case. Thereby, the helical spring 31 will force the bolt 26 out to its outer position where it will engage with the strike plate 32 of the door case when the door is closed. This situation is shown in fig. 1.

At the same time the sliding bolt 12 is forced out to its<BR> outer position where it can be locked by arbitrarily turning the actuator to ciphers that on the contrary do not correspond to the code whereby locking can be effected.

Only persons knowing the code will now be able to unlock the lock again. This takes place by turning to the code and then pushing the sliding bolt 12 inwards in the case with a push on the head 13 of the sliding bolt. Thereby, the base 14 of the sliding bolt turns the gear segment 24 so that the bolt 26 is pulled free of the strike plate 32 of the door case against the action of the helical spring 31. By arbitrarily turning the actuator to ciphers that on the contrary do not correspond to the code, the bolt is then kept in the position in which the door freely can be opened and closed. This situation is shown in fig. 2.

In both situations the head 13 of the bolt is well protected inside the outer part 20 of the tubular actuator, said part being, just as the head, preferably made of a strong material such as hardened steel which unauthorized persons will not be able to attack destructively by means of common tools.

In this embodiment the combination lock according to the invention is well suited as supplement to a key lock with inside catch for unlocking the lock. The combination lock is then mounted as the catch of the key lock on the inside of the door. In locked state the combination lock then prevents thieves from getting out of the door with stolen goods. But persons knowing the combination lock can in case of e. g. fire easily unlock the door from the inside and get out of the door.

Figs. 4 and 5 show in a second embodiment the combination lock used for locking an only fractionally shown door l'to an only fractionally shown door case 2. This embodiment corresponds to and functions in the same way as the first embodiment of figs.

1-3. Like parts are therefore similarly referenced.

The difference is that the combination lock is double with a part mounted on either side of the door with a joint guiding tube 4 and a joint bolt 26. The locking cases 3a and 3b of the parts are made with ends entering each other. Therefore, both locking cases are secured by the joint guiding tube at the same time.

Each of the parts for the second embodiment of figs. 5 and 6 can be used separately without difficulty for, in the same way as the first embodiment of figs. 1 and 2, being mounted on and operated from only one side of the door, for example the inside.

Just as the first embodiment of figs. 1 and 2 the combination lock is locked by the spring power of the helical spring 31 whereas it is unlocked by manually pushing the head 13 of the sliding bolt into the tubular outer actuator part 20.

In fig. 4 the door is locked. The bolt 26 is pushed into engagement with the strike plate 32 of the door case by the spring power of the helical spring 31 whereas both sliding bolts 12 are pushed out to their outer positions. If the actuator in this position is turned arbitrarily, the lock can now only be unlocked by a person knowing the code.

The lock can be unlocked again by turning to the code and push the head of one of or both of the sliding bolts into the outer part 20 of the associate actuator. In fig. 5 the lock has been unlocked by merely pushing the head of the-seen in the figure-right sliding bolt into the outer actuator part 20 whereas the left sliding part still is in its outer position.

As appears, the combination lock can thus be unlocked from both the outside and inside of the door. If the actuator on one side is turned away from the code and the combination lock is in its locked state, the actuator on the first side must however first be coded before the combination lock can be unlocked from the other side.

Both lock types have the advantage that a thief cannot unlock the lock and get out of the door with stolen goods. The combination lock in the second embodiment furthermore has the considerable advantage that a person being behind a locked door and knowing the code will be able to lock himself or herself out without a key which during e. g. a fire cannot be found in the hurry or which can be in a place on fire and therefore inaccessible.

Figs. 6 and 7 show a third embodiment of the combination lock used for locking an only fractionally shown door 1 to an only fractionally shown door case 2. This third embodiment is a variant of the second embodiment of figs. 4 and 5, and like parts are therefore similarly referenced.

As in figs. 4 and 5, there can be code discs on both sides but in the case shown, there are only code discs on the lock part that is located on the inside of the door where the code discs are protected the best against attempts to break up the lock from the outside.

On the inside the combination lock is therefore arranged in the same way as the first embodiments of figs. 1-5, except that the spacer ring 29 is missing and that the inner actuator part 33 is designed in a different way. On the outside, the inner actuator part 34 is also designed in a different way.

On each of the opposite end faces of the two inner actuator parts a gear rim 35 is made that engages two toothed wheel 36 rotatably journaled on the guiding tube 4. As there are no code discs on the outside, the associate sliding bolt 37 has no circumferential grooves and longitudinal key slot.

If the actuator is turned on one side of the door e. g. clockwise, this turning is transmitted via the gear rims 35 and the toothed wheel 36 automatically to a synchronous turning clockwise of the actuator on the other side of the door. Thus, there is only need for one set of code discs with correspondingly designed sliding bolt.

In the second embodiment of figs. 4 and 5 the combination lock was designed as a latch lock unlocked from one of the sides of the door by pushing in the sliding bolt head 13 on this side.

In locked state both sliding bolts 12 therefore had to be in their respective outer positions.

In this second embodiment there is no alternative to this solution. For if the combination lock was arranged so that it instead was locked by pushing the sliding bolt head on e. g. the outside in, a person on the inside will not be able to unlock the combination lock. For the lock can now only be unlocked by means of the actuator on the outside but this actuator is exactly inaccessible from the inside.

This problem is sought solved by means of the third embodiment of figs. 6 and 7, in that a combination lock locked from one side by pushing in the sliding bolt head without difficulty can be unlocked from the other side merely by operating the actuator on this side as the two actuators now follow each other's movements synchronously.

In this third embodiment the combination lock can therefore function as the only lock on a door and fully replace a lock of the type that is operated from both sides with a key which after all can be forgotten or get lost. If a key is lost, it can mean expenses to a new cylinder and new keys.

Another advantage is that the actuator on the inside of the door immediately reveals if an unauthorized person is manipulating the actuator on the outside in an attempt to unlock the combination lock whereby persons on the inside of the door are warned so that help can be called for if necessary. The actuators can possibly be connected to an alarm which is activated on incorrect coding.

When the door is to be locked, it will feel natural if the user has to actively operate the lock during this by for example pushing in the sliding bolt head with the thumb. The user can immediately see if the door is not locked as the head in this case is extending out of the actuator. The head can possibly have a contrasting colour or another marking for clearly indicating that the combination lock is not locked.

Possibly, the sliding bolt heads can be connected to another alarm which e. g. can give off a tone or play a melody when the combination lock is unlocked from one side or the other but which is immediately disrupted by turning one of the actuators.

By means of the above arrangement the combination lock according to the invention will have the considerable advantage over conventional locks that it is intelligent and therefore able to inform the user of actions that should not take place and actions that should be done.

In the example shown in figs. 6 and 7 the combination is locked when one of the sliding bolt is in its inner position.

Thereby the extra security is obtained in that the code discs and gear segment are not affected by blows to a sliding bolt head in locking position. The sliding bolt cannot be pushed out of the locking case either as it is not possible to get a grip on its head which is hidden in the actuator. The combination lock according to the invention is therefore burglar proof.

In fig. 6 the combination lock is locked, the sliding head on the inside of the door being in its inner position. The sliding head on the outside is still in its outer position. If desired, the sliding bolt on the outside can without difficulty easily be pushed into the associate actuator part.

In fig. 7 the combination lock is unlocked and both sliding bolts are in their outer positions.

Figs. 8 and 9 show in a fourth embodiment the combination lock used for locking two only fractionally shown windows 38 to a window bar 39.

This fourth embodiment corresponds in principle to the first embodiments of figs. 1-7. Like parts are therefore similarly referenced.

However, the head 40 of the bolt is now hollow and between the head and the bottom of the outer actuator part 20 a compression spring 41 is located.

In the guiding tube 42 two bolts 43 are displaceably located that in their locking positions engage with fittings 44 screwed onto the frames 45 of the windows by means of e. g. one-way screws (not shown).

On opposite sides of each bolt 43 is located a swivel pin 46 and on opposite sides of the base 14 of the sliding bolt are placed other swivel pins 47. The swivel pins are connected to a total of four links 48 all forming an angle with the axis of the sliding bolt in all the possible positions of this bolt.

This arrangement can also be designed in other suitable ways (not shown). However, the essential is that the links are pivotally connected to the bolts and sliding bolt respectively.

Just as in the first embodiments the code is turned when the lock is to be locked or unlocked so that the sliding bolt freely can be displaced in relation to the locking case.

In fig. 6 the sliding bolt has, by a manual push on the head 40, been pushed into its inner position against the action of the compression spring 41. Thereby the base of the sliding bolt has, by means of the links 48, pushed the bolts out of engagement with the fittings 44 on the closed windows 38. By arbitrary turning of the outer actuator part 20 locking of the windows is effected.

However, the locked windows can easily be unlocked again by merely turning to the code, after which the compression spring 41 forces the sliding bolt out to its outer position so that its base pulls the bolts 43 out of engagement with the fittings on the window frames by means of the links 48.

In figs. 8 and 9 two windows can be locked simultaneously by means of the same combination lock. If there is only one window, an embodiment is used (not shown) that corresponds to the one in figs. 8 and 9 but without bolt and link in the side facing oppositely of the window.

Figs. 10 and 11 show in a fifth embodiment the combination lock used for locking a cremone bolt 49 with an edge rail 50 and a shoot 51 in an only fractionally shown door 52. The same arrangement can be used for a window.

The combination lock can be arranged in the same way as the first embodiment of figs. 1 and 2, which only can be operated from one side of the door, or as the second and third embodiments, respectively, of figs. 4-5 and 6-7, which can be operated from both sides of the door.

In figs. 10 and 11 showing the combination lock in cross section only the locking case 1, guiding tube 4 and the bolt 53 are seen, the bolt in this case being constructed with an obliquely bevelled end part 54. A corresponding cut 55 is made in the shoot 51.

In fig. 10 the shoot 51 is pushed up to a position in which the cremone bolt is locking the door 52 by engaging the door case (not shown). The bolt 53 is in engagement with the cut 55 in the shoot which thereby is locked in its locking position.

In fig. 11 the bolt 53 is pulled free of this engagement, after which the cremone bolt can be taken out of its locking position and the door be opened.

Only exemplary embodiments of the coupling for making the sliding bolt and the bolt displace themselves simultaneously by operating the lock are described above and shown in the drawing.

Within the scope of the invention any other suitable coupling can however be used for this purpose just as each of the couplings described and shown can be adapted to one of the other embodiments of the combination lock.