SAFETY LOCK WITH HIGH FLEXIBILITY OF USE
DESCRIPTION
The present invention refers to a safety lock with high flexibility of use, with use in general for doors, gates, safes etc.
Bitted locks are known comprising, inside a stiff box casing, a bolt with horizontal movement borne by a support plate, to which a plurality of retainer plates or gorges is associated, with movement orthogonal to the bolt or with oscillating movement.
The retainer plates have serrated windows defining notches of differentiated passage whose alignment opens a passage for a retainer element or Mentonnet fixed to the support plate.
Such locks are driven by a key with a suitable coding profile, which can be of single or double bit type: the rotation of the key collimates the notches of the retainer plates and opens the passage for the retainer element .
Notwithstanding the high level of safety of such locks, when they are installed in buildings still under construction, it may be necessary to provide a key to personnel employed in the working yard so to permit their access to the building.
To avoid a fraudulent use of the lock, temporary or building yard keys are foreseen which differ from the main or proprietor keys which will be used by the user after the
building yard closes, due to the fact that the temporary keys can only partially operate the lock, for example only with only half-turn for the opening of the spring latch or with two turns in the case of four-turn locks.
In these situations, there remains the risk of fraudulent use of the lock each time the final user only partially closes it.
Safety locks have therefore been introduced on the market in which the coding operation foresees the substitution of the pack of retainer plates, which leads to the use of particular tools which are so complex that only specialised personnel can carry out the operation with the aid of a detailed instructions manual.
Other safety locks are known on the market which permit the recoding without the need to substitute parts of the mechanism inside the box casing of the lock itself.
In the latter locks, in general, it is not possible to reuse the disabled keys, or it is possible to reuse them only through the use of a specific restoration key.
The technical task proposed by the present invention is therefore that of making a safety lock with a high flexibility of use which permits eliminating the lamented technical drawbacks of the prior art .
In the scope of this technical task, one object of the invention is that of making a safety lock with high flexibility of use which is recodable in an automatic,
extremely simple and quick manner.
Another object of the invention is that of making a safety- lock with high flexibility of use which has more than one and preferably more than two distinct codes which can be attained in a completely automatic manner.
Not the least object of the invention is that of making a safety lock which is structurally simple and economical as well as functionally efficient.
The technical task, as well as these and other objects are achieved according to the present invention by making a safety lock in accordance with claim 1, enclosed below.
The safety lock of the present invention can be recoded in an entirely automatic manner on any one design coding, chosen as desired.
The recoding is carried out directly by the key inserted for the first time in the lock, which is automatically self- enabled, automatically disabling every key which had been previously used for the execution of any function.
The recoding operation is extremely simple and quick and all keys of the lock can be directly tested by the builder.
Or, the lock can also be restored for the reuse of the previously disabled keys.
Other characteristics of the present invention are defined, moreover, in the subsequent claims.
Further characteristics and advantages of the invention
will be more evident from the description of a preferred but not exclusive embodiment of the safety lock according to the finding, illustrated as indicative and non-limiting in the enclosed drawings, wherein:
Figure 1 shows a side elevation view of the safety lock in accordance with a preferred mode of achieving the invention, with the recoding element in its initial size and in unlocked position of the lock, with the bolt retracted;
Figure 2 shows a side elevation view of the safety lock of figure 1, with the recoding element in its intermediate size and in unlocked position of the lock, with the bolt retracted;
Figure 3 shows a side elevation view of the safety lock of figure 1, with the recoding element in its final size and in unlocked position of the lock, with the bolt retracted;
Figure 4 shows a side elevation view of the safety lock of figure 1, with the recoding element in its initial size and in locked position of the lock, with the bolt retracted;
Figure 5 shows a side elevation view of the safety lock of figure 1, with the recoding element in its initial size and in locked position of the lock, and with the bolt extracted with two turns;
Figure 6 shows a side elevation view of the safety lock of figure 1 with the recoding element in its initial size and in locked position of the lock, and with the bolt extracted with four turns;
Figure 7 shows a perspective view of the safety lock of figure 1 with the recoding element in its initial size and in unlocked position of the lock, and with the bolt retracted;
Figure 8 shows a side elevation view of the safety lock of figure 1 with the recoding element in its intermediate size and in locked position of the lock, and with the bolt retracted;
Figure 9 shows a perspective view of the safety lock of figure 1 with the recoding element in its intermediate size and in locked position of the lock, and with the bolt retracted;
Figure 10 shows a side elevation view of the safety lock of figure 1 with the recoding element in its final size and in locked position of the lock, and with the bolt retracted;
Figure 11 shows a perspective view of the safety lock of figure 1 with the recoding element in its final size and in locked position of the lock, with the bolt retracted;
Figure 12 shows an exploded perspective view of the safety lock of figure 1, from which the cover of the box casing has been removed;
Figure 13 is an exploded perspective view of the recoding element of the safety lock of figure 1; and
Figure 14 shows the three keys of the safety lock of figure 1.
With reference to the mentioned figures, a safety lock is
indicated overall with the reference number 1.
The safety lock 1 is of . four-turn type and has three driving keys 2a, 2b and 2c of double bitted type.
The lock 1 comprises a stiff box casing 3 at whose interior a latch 4 and a bolt 5 are kinematically associated.
The bolt 5 in particular is borne by a support plate 6 which is horizontally movable between a retraction position of the bolt 5 inside the box casing 3 for the opening of the lock, a partially extracted position corresponding to the closing of the lock with two turns, and a completely extracted position corresponding with the closing of the lock with four turns .
The support plate 6 is superimposed by a pack of retainer plates or gorges 7, of which, as shall be seen, one is special, indicated with T .
Every retaining plate 7 and 7', respectively, is vertically movable and has a serrated windows 8 and 8' respectively defining passage notches 9 and 9', respectively, corresponding to the coding of the keys 2a, 2b and 2c.
The notches 9' of the special retaining plate 7' are in particular all equivalent.
A retaining element 10 or Mentonnet is fixed to the support plate 6 of the bolt 5, and is positioned inside the windows 8, 8' .
Each key 2a, 2b, 2c in use is capable of collimating the
teeth of the windows 8, 8' so to open a passage corridor for the retaining element 10.
Every retaining plate 7, 7' has five notches which are subdivided into notches X for the driving of the second and fourth turn and the latch 4 and notches Y for the driving of the first and third turn of the bolt 5.
Every key 2a, 2b, 2c has two different bits, one corresponding to the notches X and one corresponding to the notches Y and each bit has six cuts, one for each retainer plate 7, 7' , for a total of twelve notches cuts named with the letters A-L, as shown in figure 14.
The two bits are repeated, rotated 180° with respect to the centre of the key, since the retainer plates are positioned asymmetrically inside the box casing 3. The central zone 50 of each key is not coded and serves for the horizontal drive of the support plate 6 of the bolt 5.
In particular, it must be noted that the bits of the keys 2a, 2b and 2c differ from each other only for the cut which drives the special retainer plate 7' and in particular for the cut B, which progressively increases its code radius from the key 2a to the key 2c, and for the cut K which progressively increases its code radius from the key 2a to the key 2c.
The lock 1 advantageously comprises a variable size recoding element 11 having a succession of sizes, in the current case three identified in the figures from the
reference kθ, kl and k2 which is selectively aligned with the notch 100.
Each size of the recoding element 11 enables a corresponding key 2a, 2b, 2c and disables every key enabled by every other preceding size of the recoding element 11.
In the particular current case, the recoding element 11 in the initial size k0 enables the key 2a, in the intermediate size kl enables the key 2b and disables the key 2a, and in the final size k2 enables the key 2c and disables both the key 2a and the key 2b.
The coding element 11 is supported by an additional plate 70 which is tightly bound to the stiff box casing 3 and has a slot 71 crossed by the retainer element 10.
Each key 2a, 2b, 2c has its own control means of the recoding element 11 adapted to automatically restore it into the size which enables it when the recoding element 11 is found in a size preceding that which enables it.
The control means present in each key 2a, 2b and 2c consist of corresponding cuts B and K which drive the special retainer plate 7' .
The recoding element 11 has an additional retainer element 12 and is movable, in particular vertically movable, between a locking position in which the additional retainer element 12 locks the lock 1 and an unlocking position in which the additional retainer element unlocks the lock 1.
The recoding element 11 can be driven indirectly by the control means present in each key 2a, 2b, 2c, in the current case by means of a movement grip tab 13, projecting from the special retainer plate 7' and adapted to interfere with a foot 14 of the recoding element 11, or in a different embodiment by means of a movement transmission lever interposed between the recoding element 11 and the control means present in each key 2a, 2b, 2c.
Naturally, it is also conceivable, in a different embodiment of the present invention, that the recoding element 11 can be driven directly by the control means present in each key 2a, 2b, 2c.
The recoding element 11 comprises at least two components having a mechanical coupling of telescopic type, capable of varying the overall length of the recoding element 11, optionally permitting, as shall be seen, the possibility of restoring a size preceding the current size.
In a different embodiment of the present finding, the recoding element can be of friction type (with at least two components which are coupled with each other with a certain friction which permits them to keep their given size) or of plastic deformation type (a single plastically deformable component) , the latter type leading to a structural simplification which however does not make possible the restoration of the recoding element into a preceding size thereof, the plastic deformation being irreversible.
In the particular case, the recoding element comprises a first longitudinal element 15 and a second longitudinal element 16 substantially parallel and slidably coupled along a sliding axis 18 parallel to their longitudinal axis.
The first and second longitudinal elements 15 and 16 have reciprocal setting means in a succession of positions along their sliding axis 18.
The setting means comprise a tooth 17 which can be selectively and elastically inserted in a seat of a plurality of seats of matching form to the tooth 17 and arranged in succession along the sliding axis 18.
The seats are indicated with the symbol kθ, kl and k2, every size of the recoding element 11 corresponding with the coupling of the tooth 17 in one of these.
The first longitudinal element 15 has a longitudinal hollow space 19 for guiding the sliding of the second longitudinal element 16 along the sliding axis 18.
The hollow space 19 is open at its side, through which the second longitudinal element 16 is inserted.
The recoding element 11 has at its apex a transverse extension 24 at whose end the additional retainer element 12 is positioned.
In particular, the transverse extension 24 is made in a single piece with the first longitudinal element 15.
The grip foot 14 of the lifting force of the recoding
element 11 is instead made of a single piece with the second longitudinal element 16.
The lock 1 then has a return spring 25 of the recoding element 11, towards the lowered position in which the additional retainer element 12 locks the support plate 6.
The return spring 25 has a spiral part positioned in a seat 26 made in the transverse extension 24, an arm 40 associated with a fixed part 41 of the lock 1 and an arm 27 adapted to elastically oppose the lifting of the recoding element 11.
The additional retainer element 12 is positioned in a slot 28 of the support plate 6.
The slot 28 has, on its lower profile, a plurality of coupling seats 29 of the additional retainer element 12 for locking the support plate 6, and on its upper profile, one or more cams 30 opposing the lifting of the additional retainer element 12.
In particular, there is a cam 30 for every position: initial (in the closing sense) , intermediate (in the closing and opening sense) and final (in the opening sense) . In this manner, one obtains the recoding in any possible position and/or drive direction.
In the solution illustrated for locking the lock 1, the additional retainer element 12 is capable of exerting a locking action of the support plate 6 of the bolt, but in a different embodiment in accordance with the present invention
the additional retainer element 12 can be capable of directly or indirectly preventing the movement of other movable parts of the lock 1, for example one or more retainer plates or even the same drive keys .
Preferably, as illustrated, the lock 1 has restoration means of the recoding element 11 into any one of its preceding sizes.
The restoration means comprise at least one grip 31 for a reset tool (not shown) , made on the surface of the recoding element 11 and accessible through a hole 32 of the box casing 3.
The access hole 32 is present on the side of the box casing 3 from which the bolt exits outward, so to permit the reset only if the lock is open.
The access hole 32 in a different embodiment in accordance with the present invention can be accessible from the side of the lock turned towards the internal side of the environment isolated by the door in which the lock is mounted.
The grip 31 has a standard form so to be driven by a standard tool, and is for example a rectilinear track for a flat head screwdriver 31, but it can likewise have a dedicated form, for being driven by a dedicated tool, or even have a coding so to be driven only by a coded tool .
The functioning of the lock according to the invention appears evident from that described and illustrated, and in particular is substantially the following.
Initially the recoding element 11 is in its size kO .
With the key disconnected, the retainer plates are aligned but the notches of the retainer plates 7, 7' are misaligned and the main retainer element 10 engages the teeth of the retainer plates 1,1' , preventing the movement of the bolt.
When a key is inserted and rotated in the lock, each cut of each of its bits is engaged with the corresponding retainer plate.
The lock 1 is initially driven through the enabled key 2a.
During the first turn, the cuts G, H, I, J, L of the key 2a move the retainer plates 7 so to collimate the notches 9 and open the passage of the main retainer element 10.
The cut K of the key 2a is engaged with the special retainer plate 7' which by means of the tab 13 is engaged with the foot 14 of the recoding element 11, lifting it. Consequently, the additional retainer element 12 integral with the recoding element 11 is released from the coupling seat 29 in which it is housed and frees the support plate 6. Since the passage corridor of the main retainer element 10 opens in a synchronized manner, and the support plate 6 is released from the additional retainer element 12, the bolt 5 can be moved.
During the second turn, the notches A, C, D, E, F of the key 2a move the retainer plates 7 to collimate the notches 9 and open the passage of the main retaining element 10.
The cut B of the key 2a is engaged with the special retainer plate 7' which by means of the tab 13 is engaged with the foot 14 of the recoding element 11, lifting it. Consequently, the additional retainer element 12 integral with the recoding element 11 is released from the coupling seat 29 in which it is housed and frees the support plate 6. Since the passage corridor of the main retainer element 10 opens in a synchronised manner, and the support plate 6 is released from the additional retainer element 12, the bolt 5 can be moved and the additional retainer element 12 is accommodated in the coupling seat 29 following that which was previously occupied.
The .functioning is repeated for the subsequent turns.
The cuts B and K of the key 2a have the smallest code radius of the keys 2a, 2b and 2c. Such code radius is designed so to generate a lifting path of the recoding element 11 which is sufficient only to release the additional retainer element 12 from the coupling seat 29 but not sufficient to make it interfere with the cam 30, from which therefore no stress is transmitted to the recoding element 11.
When at the end of every turn, the bit of the key 2a is released from the retainer plates 7, 7', suitable helical return springs 42, interposed between the retainer plates 7 and the fixed part 41, bring the retainer plates 7 back in the lowered alignment position, while the return spring 25
brings the recoding element 11 back towards the lowered position in which the additional retainer element 12, being engaged in the coupling seat 29, locks the support plate 6.
We will now assume, after the use of the key 2a, a first use of the key 2b in the lock 1.
The initial size of the recoding element is k0.
Since the bitting of the key 2b is identical to that of the key 2a, except for the notches B and K which control, however, the special retainer plate 7', and since the special retainer plate 7' is coded for all keys, the lock 1 permits an initial recognition of the key 2b which can begin its first turn. The cuts B and K of the key 2b have a code radius which is greater than the cuts B and K of the key 2a. In this situation, the cut K generates during the first turn a lifting course of the recoding element 11 which is sufficient not only to release the additional retainer element 12 from the coupling seat 29, but also to make it interfere with the opposing cam 30, from which therefore a downward thrust force is exerted which, being opposed to the lifting of the recoding element 11, generates a longitudinal compression stress which is sufficiently intense to overcome the force with which the first and the second longitudinal element 15 and 16 are coupled: the tooth 17 slides along the sliding axis 18 and is inserted in the subsequent seat kl . Already at the end of the first turn, therefore, the size of the recoding element 11 has been modified.
In the new size kl, the recoding element 11 is more contracted longitudinally than the size kO and therefore, if one desires to use once again the key 2a, the lifting path of the special plate 7' generated by the cuts B and K of the key 2a is no longer sufficient to lift the recoding element 11, not even for releasing the additional retainer element 12 from the related coupling seat 29. Hence the key 2a is automatically disabled at the attainment of the size kl .
We now assume a first use of a key 2c in the lock 1 in which the dimension of the recoding element is kl .
Since the bitting of the key 2c is identical to that of the key 2b except for the cuts B and K, the lock 1 permits an initial recognition of the key 2c which begins its rotation. The cuts B and K of the key 2c have a code radius greater than the cuts B and K of the key 2b. In this situation, the cut K generates, during the first turn, a lifting path of the recoding element 11 which is sufficient not only to release the additional retainer element 12 from the coupling seat 29 but also make it interfere with the opposing cam 30 from which, therefore, a downward thrust force is exerted which, being opposed to the lifting of the recoding element 11 generates a longitudinal compression stress which is sufficiently intense to overcome the force with which the first and second longitudinal element 15 and 16 are coupled: the tooth 17 slides along the sliding axis 18 and is inserted in the subsequent seat k2.
In the new dimension k2, the recoding element 11 is more contracted longitudinally with respect to the dimension kl (and is even more so with respect to the dimension kθ) and therefore, if one wishes to use the key 2b again, the lifting path of the special plate 7' generated by the cuts B and K of the key 2b is no longer sufficient to lift the recoding element 11, not even to release the additional retainer element 12 from the related coupling seat 29. Hence the key 2b is automatically disabled following the achievement of the dimension k2, and the key 2a remains even more so disabled.
At this point, in order to restore a disabled key, it is possible to insert a screwdriver into the hole 32, direct it into the grip 31 and lever the screwdriver itself or simply rotate it to make the first longitudinal element 15 slide with respect to the second longitudinal element 16 towards the dimension kl or k0.
Naturally, it is possible to use the key 2c after the key 2a without passing to the key 2b: at the first use of the key 2c after the key 2a, the recoding element 11 carries out a double jump, from the dimension k0 directly to the dimension k2.
Likewise, it is possible to restore the dimension kO beginning directly from the dimension k2.
The lock thus conceived is susceptible to numerous modifications and variations, all falling within the scope of the inventive concept/ moreover, all details can be
substituted by technically equivalent elements.
The minimum number of recoding sizes is two. The number of sizes of the recoding element is equal to the number of keys which in turn is equal to the number of distinct recoding radii of the cut which drives the special retainer plate.
The lock is of the type more generally having one or more superimposed or offset retainer plates with translational or oscillatory movement, and the special retainer plate can occupy any position in the set of the retainer plates, and consequently the cuts of the key which drive it can be in any position in the key bitting.
The key in turn can be of one or two bit type, with half- turn or two, four or additional turns, and the change of size can occur at the first half-turn of any one turn, either in opening or closing.
In practice, the materials used, as well as the sizes, can be of any type according to the needs and the state of the art.