The present invention relates to a multiple-key lock, particularly to a lock that can be operated by means of at least two different keys, one of such keys being designated master key and the other keys being generically designated auxiliary keys.

The auxiliary keys have a code that is similar to the code of the master key (which differs in the depth of the code of certain portions) and are all mutually identical. This type of lock can be useful when it is necessary to enable access for a certain period to a plurality of people: once the need for which it is necessary to resort to this plurality of people ends, it is possible, by means of the master key, to permanently disable the functionality of the auxiliary keys. In practice, it is possible to modify the operating configuration of the lock in order to prevent it from being opened by means of the auxiliary keys.

Background art

The main drawback of this type of lock is the uniqueness of the enabling of the auxiliary keys: once they are disabled, it is no longer possible to restore their operation.

The possibility to resort to auxiliary keys, therefore, cannot be repeated. With a single lock it is possible to use the respective auxiliary keys only until they are disabled for the first time; at that point it is no longer possible to obtain this function from the lock.

Another very important drawback of existing multiple-key locks is linked to the impossibility to create different levels of clearance: for example, it is impossible to create a lock in which there is an auxiliary key of a first type which, once disabled, does not compromise the clearance for opening on the part of a secondary key of a second type. Disclosure of the invention

The aim of the present invention is to solve the above-mentioned drawbacks, by providing a multiple-key lock in which it is possible to disable and reenable a temporary key for an undetermined number of cycles. Within this aim, an object of the invention is to provide a multiple- key lock in which there are at least two types of auxiliary key with a different code, which can be enabled and disabled independently.

Another object of the invention is to provide a multiple-key lock that is particularly secure and protected against break-in attempts. Another object of the present invention is to provide a multiple-key lock which has low costs, is relatively simple to provide in practice and is safe in application.

This aim and these and other objects, that will become better apparent hereinafter, are achieved by a multiple-key lock of the type that comprises a box-like containment body provided with openings along one of its perimetric faces for the passage of at least one latch and of at least one bolt, said bolt being actuated by means of a respective band that performs a translational motion and is actuated so as to perform a translational motion by means of the rotations of at least one key, the rotations of said at least one key being dependent upon the movement into the disengagement configuration, with respect to a fixed pin on the band, of a plurality of coded plates, characterized in that it comprises at least one sliding shaft that has at least one protrusion, said shaft being movable between a first configuration, in which said at least one protrusion is aligned with a respective coded plate and said plate is substantially locked so as to rest thereon, and a second configuration, in which said at least one protrusion is spaced from the respective plate and said plate is free to perform a translational motion as a consequence of rotations of the key. Brief description of the drawings Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of the multiple-key lock according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein: Figure 1 is a partially sectional perspective view of a first embodiment of a multiple-key lock according to the invention;

Figure 2 is a partially sectional perspective view of the multiple-key lock of Figure 1 without some plates;

Figure 3 is a partially sectional perspective view of the multiple-key lock of Figure 1 during the initial instants of rotation for closure of a master key;

Figure 4 is a partially sectional perspective view of the multiple-key lock of Figure 3 without some plates;

Figure 5 is a partially sectional perspective view of the multiple-key lock of Figure 1 during steps that are subsequent to the steps of Figure 3 of the closing rotation of a master key;

Figure 6 is a partially sectional perspective view of the multiple-key lock of Figure 1 during the final step of the closing rotation of a master key, with bolts that are fully extracted and the protrusion disengaged from the plates;

Figure 7 is a schematic view of the multiple-key lock of Figure 6; Figure 8 is a partially sectional perspective view of the multiple-key lock of Figure 1 according to the invention in the configuration for reenabling the secondary key, with the bolts completely retracted and the master key rotated counterclockwise through approximately 90°, a tool producing a backward forcing of the shaft in order to lock a protrusion below a respective plate;

Figure 9 is a partially sectional perspective view of the multiple-key lock of Figure 1 according to the invention; Figure 10 is a perspective view of a particular practical embodiment of the detail A of Figure 9;

Figure 11 is a perspective view of a further practical embodiment of the detail A of Figure 9;

Figure 12 is a partially sectional perspective view of a second embodiment of the multiple-key lock according to the invention;

Figure 13 is a partially sectional perspective view of the multiple-key lock of Figure 12 without some plates;

Figure 14 is a partially sectional perspective view of the multiple-key lock of Figure 12 according to the invention; Figure 15 is a perspective view of a particular practical embodiment of the detail B of Figure 14;

Figure 16 is a perspective view of a further practical embodiment of the detail B of Figure 14;

Figure 17 is a partially sectional perspective view of the multiple-key lock of Figure 12 according to the invention in a configuration in which the bolts are extracted further with respect to Figure 12;

Figure 18 is a partially sectional perspective view of the multiple-key lock of Figure 17 without some plates;

Figure 19 is a partially sectional perspective view of a third embodiment of the multiple-key lock according to the invention;

Figure 20 is a partially sectional perspective view of the multiple-key lock of Figure 19 with the bolts fully extracted;

Figure 21 is a schematic view of the multiple-key lock of Figure 20;

Figure 22 is a partially sectional perspective view of the multiple-key lock of Figure 19 according to the invention in the configuration for reenabling the secondary key, with bolts and transmission elements that are completely retracted and with the master key rotated counterclockwise through approximately 90°, a tool producing a backward forcing of the shaft in order to lock a protrusion below a respective plate; Figure 23 is a partially sectional perspective view of a fourth embodiment of the multiple-key lock according to the invention;

Figure 24 is a partially sectional perspective view of the embodiment of Figure 23 of the multiple-key lock according to the invention, with the bolts fully extracted; Figure 25 is a partially sectional perspective view of a fifth embodiment of the multiple-key lock according to the invention;

Figure 26 is a partially sectional perspective view of the embodiment of Figure 25 of the multiple-key lock according to the invention with the key turned; Figure 27 is a partially sectional perspective view of the embodiment of Figure 25 of the multiple-key lock according to the invention, with the bolts and the transmission elements fully extracted;

Figure 28 is a partially sectional perspective view of the embodiment of Figure 25 of the multiple-key lock according to the invention, with the bolts and the transmission elements fully retracted.

Ways of carrying out the invention

With reference to the figures, the reference numeral 1 generally designates a multiple-key lock.

The multiple-key lock 1 comprises a box-like containment body 2, which is provided with openings 3 along one of its perimetric faces. As a first approximation, it can be observed that the box-like body 2 is shaped like a parallelepiped that is flattened transversely: the two larger faces are mutually opposite and are mutually coupled by means of the perimetric edge. Such perimetric edge is provided with the openings 3, which are designed for the passage of at least one latch and of at least one bolt 4; the bolt 4 is actuated by means of a respective band 5 that performs a translational motion (which is normally known as rod and/or element for moving the bolts 4). The band 5 in turn is actuated so as to perform a translational motion by means of the rotations of at least one key 6; in particular, the rotations of the at least one key 6 are dependent upon the movement into the disengagement configuration, with respect to a suitable fixed pin 7 (also known as square pin as a consequence of its cross-section, which is normally square), on the translating band 5, of a plurality of coded plates 8.

The coded plates 8 are provided with a portion that interferes with the stroke of the key 6 during rotation: such interfering portion is contoured so that when the key 6 is arranged transversely with respect to the keyhole for insertion in the lock 1 , the plates 8 lifted by the key 6 (since the interfering portions rest on respective areas of the code of the key 6) are aligned conveniently in order to allow the pin 7 to perform a translational motion along a suitable trajectory that is identified by slots 9 of the juxtaposed plates 8.

The lock 1 according to the invention comprises in particular at least one sliding shaft 10, which is provided with at least one protrusion 11.

The shaft 10 can move between a first configuration, in which the at least one protrusion 11 is aligned with a respective coded plate 8 (a configuration in which the plate 8 is substantially locked so as to rest on the protrusion 11), and a second configuration, in which the at least one protrusion 11 is spaced from the respective plate 8 (a configuration in which the plate 8 is free to perform a translational motion as a consequence of rotations of the key 6).

The shaft 10 is arranged, according to a particular embodiment of particular interest in practice and in application, below the plates 8 and comprises a protruding tooth 12 that interferes with the stroke of the band 5.

In particular, when the band 5 is arranged proximate to the edge of the box-like body 2 for the exit of the bolts 4 (i.e., when the lock 1 is moved into the closed configuration, with the bolts 4 fully extracted), the shaft 10 has been moved by the band 5 toward the edge of the box-like body 2 until it is arranged in the second configuration described earlier (disengagement of the protrusion 11 from the bottom of the respective plate 8).

The box-like body 2 comprises, along its edge provided with the openings 3, at least one passage 13 that is aligned with a portion 14 of the shaft 10. The shaft 10 can thus be moved from the second configuration (disengagement of the protrusion 11 from the bottom of the respective plate 8) to the first configuration (resting of the bottom of the plate 8 on the respective protrusion 11) by means of a tool U inserted in the passage 13 while the key 6 is turned partially to lift all the plates 8 (key arranged transversely with respect to the arrangement for insertion in the keyhole, such transverse arrangement allowing complete lifting of the plates 8 since the interfering portions of each plate 8 rest on a respective code area of the profile of the key 6).

The shaft 10 comprises, proximate to the protrusion 11, a block 15 with a substantially triangular profile, which has a cathetus 16 that rests on the edge of the protrusion 11, the other cathetus 17 jointly connected to the shaft 10 and the hypotenuse 18 that is free and directed upward so as to constitute an inclined plane.

The lock 1 comprises at least one substantially vertical transmission element 19 for the actuation of upper/lower bolts (not shown in the accompanying figures).

The transmission element 19 comprises a pin 20, which is substantially aligned with the inclined plane constituted by the hypotenuse 18 of the block 15; the descent of the transmission element 19 and of the pin 20 jointly connected thereto, which occurs as a consequence of the rotation of the key 6 to move into the operating arrangement that corresponds to the complete closure of the bolts 4 (and also of the lower/upper ones), produces a translational motion of the shaft 10 from the first configuration to the second configuration, with consequent disengagement of the protrusion 11 from the respective plate 8 by way of the action of the vertical thrust of the pin 20 on the inclined plane (the hypotenuse 18), which produces a horizontal translational motion of the plane and of the components that are jointly connected thereto.

The main characteristic in terms of technical advantages, usefulness of service and practicality in management of the lock 1 according to the embodiments is constituted by the presence of a master key and of at least one secondary or temporary key.

The master key is suitable for the complete expulsion/retraction of the bolts 4: by turning the master key counterclockwise (with respect to the embodiments shown in the accompanying figures) it is thus possible to produce the complete exit of the bolts 4; by turning it instead clockwise (again with reference to the accompanying figures) the retraction of the bolts 4 is obtained.

The complete movement of the bolts 4 (from a first limit configuration to a second limit configuration) is possible thanks to the code of the master key, which it will be defined as master code, which corresponds to the correct alignment of all the plates 8: if all the plates 8 are correctly juxtaposed, the pin 7 jointly connected to the band 5 is free to move, since its trajectory is free of obstacles and therefore the bolts 4 (jointly connected to the band 5) also can move along their entire stroke. The at least one temporary key (normally it is a single temporary key, but the possibility to use several temporary keys for a same lock 1 is not to be excluded) is suitable only for the partial expulsion/retraction of the bolts 4.

The code of the temporary key, generically termed auxiliary code, corresponds to the correct alignment of all the plates 8 except for the at least one plate 8 that is aligned with a corresponding protrusion 1 1 of the shaft 10. Therefore, the pin 7 has available only a partial stroke, since the plate 8 kept in misalignment by the protrusion 1 1 that lifts it constitutes an obstacle along its trajectory. In order to understand in an optimum and thorough manner the concept of trajectory of the pin 7 and of obstacle, it should be noted that each plate 8 comprises at least one slot 9 (previously already described) with a substantially toothed profile.

The pin 7 is adapted to engage stably within interspaces 21 between teeth 22 of the profile when the plates are raised/lowered with respect to the configuration for free translational motion: the slot 9 constitutes the path along which the pin 7 is free to perform a translational motion, any lifting and/or lowering translational motion of a plate 8 produces the interposition of a tooth 22 of the plate 8 in the free space of the slot 9, becoming in practice an obstacle for the passage of the pin 7.

In order to ensure the correct positioning of the plates 8 when the key 6 is not inserted in the keyhole (and therefore the lock 1 must be locked in a given position and it must be impossible to change this position without the aid of the key 6), it is appropriate to point out the presence of elastic means 23 arranged between suitable tabs 24 that are jointly connected to the box- like body 2 and the plates 8. The elastic means 23 are designed to force the plates 8 into the raised/lowered position and consequently make the pin 7 engage in one of the interspaces 21 , with consequent locking of the bolts 4 in this position. The particularity of the lock 1 according to the invention is that it is possible to enable and disable the temporary key an undetermined number of times by means of the tool U inserted within the hole 13 of the box-like body 2.

The installation of the lock 1 on the door (in any one of the possible embodiments) therefore allows the owner to enable a temporary key and provide it to the service staff for all the time needed to carry out the activities to be performed by such staff. Subsequently, the owner can disable the temporary key simply by fully extracting the bolts 4 by turning the master key. When trying to open the lock 1 with the temporary key after disabling, it will be impossible to turn the temporary key and therefore actuate the movement of the bolts 4.

If it is necessary to reenable the temporary key (if the need arises for new service activities and therefore the need to provide a temporary key to other staff arises), the owner merely has, in a first step a), to insert the master key in the keyhole of the lock 1 and, in a second step b), turn the master key until the bolts 4 are completely retracted.

During a third step c), it is necessary to turn the key further substantially through 90° (clockwise with reference to the embodiments shown in the accompanying figures) in order to lift all the plates 8. When the plates 8 are lifted, during a fourth step d), it is necessary to insert the tool U in the passage 13 provided on the edge of the box-like body 2 until it rests on the end portion 14 of the movable shaft 10.

In a final step e) it is necessary to push the tool U against the portion 14 of the shaft 10 to facilitate its translational motion to a stroke limit position, in which the protrusion 11 jointly connected to the shaft 10 is arranged below a respective plate 8, preventing its lowering. In this configuration, the temporary key is enabled. The invention thus conceived is susceptible of numerous modifications and variations, all which are within the scope of the appended claims; all the details may further be replaced with other technically equivalent elements.

For example, according to the embodiment shown in Figures 23 and 24, a lever 25 is interposed between the movable shaft 10 and the band 5.

The advancement of the band 5 beyond a certain position (which therefore corresponds to a rotation of the master key such as to make the bolts 4 protrude beyond a preset threshold value) forces a rotation of the lever 25 (pushed by the band 5 so as to rotate about its own fulcrum 26) until it rests on an appropriately provided step of the movable shaft 10. A further rotation of the lever 25 (as a consequence of a further advancement of the band 10) forces a translational motion of the movable shaft 10 until the protrusion 11 is completely disengaged from the respective coded plate 8. At this point the lock 1 operates only by using the master key.

Reenabling the temporary key is possible by using a tool that is inserted within a front hole of the box-like body 2, as indicated for the previously described cases (master key rotated through a quarter turn and thrust of the tool on the shaft 10 to retract it until the protrusion 11 is aligned with the respective plate 8).

Again by way of example, Figures 25, 26, 27 and 28 illustrate a further possible embodiment of the lock 1 according to the invention. In this case, the shaft 10 supports a rib 27 that is pivoted about an axis 28 to the shaft 10.

The particular shape of the rib 27 ensures that a lateral edge 29 thereof is adapted to support a pin 30 that protrudes from a portion of the transmission element 19, while the opposite edge 31 is shaped complementarily with respect to the master key.

As a consequence of a rotation of the master key beyond a limit rotation (the rotation that would be allowed also to the temporary key), a further protrusion of the bolts 4 and of the transmission elements 19 occurs. The transmission elements 19, as already mentioned, have, along their surface that faces and is proximate to the edge 29 of the rib 27, the protruding pin 30: the translational motion (descent or ascent in general) of the transmission element 19 therefore produces a corresponding translational motion of the pin 30 as well.

Since the edge 29 is conveniently shaped, such motion of the pin 30 produces a rotation of the rib 27 about the axis 28 until its edge 31 faces and is aligned with the profile of the master key.

By using the master key, the rib 27 is free to rotate further (since the edge 31 is shaped complementarily with respect to the shape of the master key) and the further rotation produces the application of a force to the axis 28 (and therefore to the shaft 10) such as to produce the translational motion thereof.

The translational motion of the shaft 10 is such as to move the protrusion 11 with respect to the plate 8 that it kept partially raised.

Once the movement has occurred, the plate 8 is free and the lock can be actuated only by means of the master key.

In this case also, restoring the operation of the temporary key is possible only by moving the master key to a particular position in which it lifts all the plates 8 and by forcing the retraction of the shaft 10 by means of the tool U. In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

In practice, the materials used, as well as the dimensions, may be any according to requirements and to the state of the art.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.