WO2012107855A1

WO2012107855A1 - Safety lock

Info

Publication number: WO2012107855A1
Application number: PCT/IB2012/050438
Authority: WO
Inventors: Marco MALIGHETTI
Original assignee: Securemme S.R.L.
Priority date: 2011-02-11
Filing date: 2012-01-31
Publication date: 2012-08-16
Also published as: RU2582944C2; LT2673432T; TR201803027T4; ITMI20110205A1; IT1403932B1; RU2013141676A; EP2673432A1; EP2673432B1

Abstract

A safety lock (1), comprises a frame defining a port for passage of a key into the lock and a bolt member (12) movably mounted on the frame and shiftable by rotation of the key in the lock between a first position corresponding to an open condition of the lock and a second position corresponding to a closed condition of the lock. At least one safety plate (4) is movably mounted on the frame and is shiftable by rotation of the key in the lock to a position enabling movement of the bolt member (12). The passage port of the key is projected right through the lock and identifies a free passageway for introduction of the key transversely of the at least one safety plate (4). A shield (S) is movably mounted on the frame and shiftable, due to displacement of the at least one safety plate (4) to an enabling position and/or of the bolt member (12) to an open position, between a permission position for passage of the key or other, in which said passage port is clear, and at least one obstruction position in which said passage port is at least partly obstructed by said shield (S).

Description

Description SAFETY LOCK Field of the invention

The present invention relates to a safety lock.

State of the art

In particular, the present invention relates to a safety lock of the type referred to as "plate lock", "lever lock" or "double-sided lock" comprising a bolt member movably mounted on a frame and shiftable by rotation of the key in the lock between a first position corresponding to an open condition of the lock and a second position corresponding to a closed condition of the lock. The safety lock further comprises a pack of safety plates or wafers movably mounted on the frame and shiftable by rotation of the key in the lock to a position enabling movement of the bolt member.

Each safety lock of the above described type can be opened/closed by a specific key preferably provided with double-sided tailpieces or blades the edges of which are indented and define the code or encryption of the key itself.

Also known are illicit opening instruments and techniques the efficiency of which is strongly connected with the experience and manual ability of the individual who makes attempts to illicitly open the lock. They consist of feeler pins or picklocks that, after tensioning the bolt member in the opening direction, slowly and selectively lift each individual safety plate in an attempt to detect the corresponding enabling position (and consequently the height of the indented key edge corresponding to such a safety plate) . The application procedure for these instruments is rather long because it is necessary to repeat it for each individual safety plate and each key turn.

In recent years a widespread instrument for illicit opening of the safety locks has been adopted, also referred to as self-learning picklock, consisting of a rod simulating the key shank, on an end of which some pins are mounted transversely of the rod. The pins are slidably mounted with friction relative to the rod so that they are compatible with the shape of the key to be reproduced.

The bolt member is tensioned in the opening direction by a pusher and the manipulation instrument is subsequently inserted, all safety plates being pushed upwards by rotation of the instrument itself. Figs. 9- 11 depict application of the manipulation instrument and pusher with reference to a safety lock of the conventional type.

Finally, by unique manoeuvring, encryption of the key (at a key turn) is obtained by oscillatory movements of the manipulation instrument aiming at finding the respective enabling position for each safety plate. In other words, the picklock of new generation simulates the presence of the key in the lock.

This new effraction technique is simplified with respect to the previously used techniques, and extends the range of possible users; in addition, it does not leave any sign of burglary or effraction. In addition, traditional safety locks appear to be rather vulnerable relative to this new effraction technique.

In addition to the above, a lever bolt is known from EP0594984 in which a barrier in the form of a disc is provided.

Scope of the invention

In this context, the technical task underlying the present invention is to propose a safety lock overcoming the above specified drawbacks of the known art .

In particular, it is an aim of the present invention to make available a safety lock capable of preventing violation even in case of application of simplified effraction techniques.

It is a further aim of the invention to propose a safety lock that is reliable in terms of operation under normal use conditions.

The technical task mentioned and the aims specified are substantially achieved by a safety lock comprising the technical features set out in one or more of the appended claims.

Brief description of the drawings

Further features and advantages of the present invention will become more apparent from the description given by way of non-limiting example of a preferred but not exclusive embodiment of a safety lock as shown in the accompanying drawings, in which:

- Fig. 1 is a diagrammatic perspective view divided into separate parts of a portion of a safety lock according to the present invention; - Fig. 2 is an enlarged front view of a detail in Fig. i;

- Figs. 3 and 4 are enlarged front views of the portion in Fig. 1 in two different operating conditions, in which some elements have been omitted to make others more prominent;

- Fig. 5 is an enlarged front view of some details in Fig. 1;

- Figs. 6 and 7 are a perspective view and a side view respectively, of the details in Fig. 5;

- Fig. 8 is an enlarged view of the detail VIII in Fig. 7;

- Figs. 9-11 are perspective views of a lock of the conventional type in the closed condition and submitted to an illicit opening attempt by a manipulation instrument and a pusher.

Detailed description of the preferred embodiments of the invention

With reference to Fig. 1, generally identified by reference numeral 1 is a portion of safety lock shown in separate parts.

In particular, it is a lock referred to as "plate lock", "lever lock" or "double-sided lock", for example associable with bolt pins not shown.

Denoted at 2 is a box closed on one side by a cover 3 and containing a pack of safety plates 4 or tumbler plates or "gorges" movably mounted inside the box in a direction parallel to their plane. Box 2 defines a lock frame .

In Fig. 1 the reference numerals relating to elements of the safety plates have been reproduced in one of the safety plate alone for the sake of simplicity. Denoted at 5 are slide slots of the safety plate adapted to respectively receive a pin 6 associated with box 2 for guiding movement of the safety plates inside the box.

An opening 7 on the cover (and a corresponding opening not shown, in the box base) enables insertion of a key for opening and closing the lock. The safety plates 4 have windows 8 with indented edges that define passage grooves 9. The safety plates further comprise edge portions 10 designed to be engaged by indented edges of two double-sided tailpieces or blades of the key defining the code or encryption of the key itself.

Opening 7 of cover 3 (and the corresponding opening formed in the box base) defines a passage port for the key that is projected along a direction transverse to the lock also at the safety plates 4, under normal use conditions of the lock. As far as the safety plates 4 are concerned, the key passes below the edge portions 10 (alternatively, the safety plates may comprise slots adapted to receive the key under normal use conditions of the lock) .

Generally, the frame defines a passage port for the key in the lock that is projected right through the lock and identifies a free passageway for insertion of the key transversely of the safety plates. Projection of opening 7 in each plane parallel to the safety plates 4 defines the passage port of the key in the lock.

When the key is introduced into opening 7 (or in the corresponding opening formed in the box base) and rotated around its axis, the indented edges of the double-sided key blades come into contact in succession with the edge portions 10 of the safety plates 4 causing translation of same (upwards with reference to Fig. 1) against the action of spring means 11 (or under gravity) .

In the following, reference will be made to the position of Fig. 1 in which rotation of the key causes lifting up of the safety plates, by this term generally meaning a movement in the vertical direction and upwards .

Denoted at 12 is a bolt member, for example made with a sheet metal plate slidably mounted inside box 2 and associable with the bolt pins not shown. In other words, the bolt member 12 is movably mounted on the frame and is shiftable by rotation of the key in the lock between a first position corresponding to an open condition of the lock and a second position corresponding to a closed condition of the lock (Figs. 3 and 4 correspond to the second position) .

In particular, movement of the safety plates 4 caused by rotation of the key is substantially perpendicular to movement of the bolt member 12 on passing from the first to the second positions and vice versa. With reference to the example shown, movement of the bolt member 12 is horizontal.

The key windows 8 and the key double-sided profiles are such shaped that rotation of the key lifts the safety plates 4 to such positions that movement of the bolt member 12 is enabled. In other words, the safety plates 4 are movably mounted on the frame and shiftable by rotation of the key in the bolt to an enabling position of the movement of the bolt member.

In particular, the bolt member comprises a safety pin 13 or "mentonnet" protruding through the windows 8 of the safety plates. The height of the indented edges or double-sided blades of the key enables alignment of the passage grooves 9 of the safety plates that define a free passageway for the safety pin 13 between the tooth tips of windows 8, at a key turn.

In the example shown each safety plate comprises four passage grooves 9 sequentially defining the passageway of the safety pin 13 at four key turns. The number of the safety plates can vary; in the example shown five safety plates are provided which correspond to five different heights of the encryption of each side of the key . In accordance with the present invention, the safety lock 1 advantageously comprises a shield S movably mounted on the frame and shiftable, preferably translatable, due to displacement of at least one safety plate 4 to the enabling position. Shifting of shield S takes place between a permission position for passage of the key or other, in which the passage port is clear (Fig. 3), and at least one obstruction position in which said passage port is at least partly obstructed by the shield (Fig. 4) .

Advantageously, the shield is disposed inside the frame, internally of box 2 for example.

Generally, shield S is adapted to generate a growing obstruction of the passage port of the key depending on the shield position; for instance, shield S at least has a substantially inclined profile S'.

In accordance with a possible embodiment, the shield is disposed parallel to the safety plates 4 and preferably is formed with an anti-manipulation plate 14, shown in detail in Fig . 2.

The anti-manipulation plate 14 is disposed parallel to the safety plates 4. As shown in Fig. 1, the anti- manipulation plate 14 is disposed in an intermediate position relative to the pack of safety plates 4; alternatively, the anti-manipulation plate can be disposed at any position relative to the pack of safety plates 4.

Slide slots of the anti-manipulation plate 14 have been identified by reference numeral 5; they are adapted to respectively receive a pin 6 associated with box 2 for guiding the movement of the anti-manipulation plate 14 inside box 2.

The anti-manipulation plate 14 comprises a window 15 having an indented edge. In particular, the window has an inclined profile 16 defining at least one apex 17. In the example shown, two opposite inclined profiles define an apex 17. The position of apex 17 corresponds to overcoming of a groove 9 with reference to the opening movement of the safety pin 13 relative to the safety plates 4. In particular, the anti-manipulation plate 14 shown in the figure comprises two apices 17 corresponding to overcoming of the first and third grooves 9 respectively, with reference to the opening movement of the safety pin 13 relative to the safety plates 4 (see Fig. 5 illustrating an anti-manipulation plate between two safety plates) . Denoted at 18 is a displacement wing, in particular a lifting-up wing, extending transversely of the planar extension of the anti-manipulation plate 14. In the example shown in the figures two displacement wings 18 are provided which extend away from the plane of the anti-manipulation plate 14 towards opposite directions. The displacement wing 18 extends in such a manner that it is disposed transversely of at least one safety plate 4 parallel to the anti-manipulation plate 14 (Figs . 5-8 ) .

In addition, the displacement wing 18 is for example disposed at an upper edge of the anti-manipulation plate 14.

In this manner, due to the movement of the safety plate 4 against the action of the displacement wing 18, the safety plate 4 drags along the anti-manipulation plate 14. In particular, with reference to the example shown, when the safety plate 4 rises, it drags along the anti- manipulation plate 14.

The displacement wings 18 define constraint means between the anti-manipulation plate 14 (shield S) and at least one safety plate. Said constraint means is operative when passing to the enabling position of the safety plate. In accordance with a possible embodiment for example shown in the accompanying drawings, at least one first displacement (lifting) of the anti-manipulation plate 14 and correspondingly of shield S is therefore generated by displacement (lifting) of at least one safety place 4 instead of being generated by the key that, at the anti-manipulation plate 14, preferably has maximum piercing.

With reference to the operation to be described subsequently, Fig. 3 shows a permission position of shield S and the anti-manipulation plate 14 (an obstruction position of the shield S and the anti- manipulation plate 14 due to the action of the safety plates alone is not shown) .

The inclined profile 16 is adapted to interact with the bolt member 12, in particular the safety pin 13, to make the anti-manipulation plate 14 further rise, for instance until it is disposed so that its apex 17 rests on the safety pin 13 (Fig. 4), on passage between the second position and first position of the bolt member 12.

Advantageously, the inclined profile 16 terminates at a support position of the anti-manipulation plate 14 on the bolt member 12, at apex 17 for example.

In general terms, the inclined profile 16 defines a shaped profile adapted to (preferably further) lift the anti-manipulation plate to a further obstruction position (Fig. 4), as clarified when describing operation of the lock according to the present invention . In other words, the shaped profile 16 and safety pin 13 form translation cam means operating between the anti- manipulation plate 14 and the bolt member 12.

With reference to the example shown, the anti- manipulation plate 14 comprises a passage slot 19 for the key. Advantageously, the passage slot 19 is delimited by a closed profile P.

Preferably, the passage slot 19 comprises a first or upper portion 19a substantially closely following or comprising the area of the key passage port (in a plane parallel to the safety plates) and a second or lower portion 19b of varying width along the height H of the anti-manipulation plate. By the term "height" it is intended the vertical size of the anti-manipulation plate with reference to Fig. 1 or 2; by width it is intended the horizontal size of the anti-manipulation plate with reference to Fig. 1 or 2, in the plane of the plate itself.

In particular, the width of the lower portion 19b of slot 19 increases from a lower edge of the lower portion, in which it is smaller than the width L' of the passage port, until opening into the upper portion where it is the same as or greater than the width of the passage port. In general terms, the lower portion 19b of slot 19 has at least one size smaller than the corresponding size of the passage port in the plane of the anti-manipulation plate.

The lower portion 19b of slot 19 confines a portion of the anti-manipulation plate 14 defining said shield S.

In accordance with a possible embodiment, not shown, the anti-manipulation plate 14 comprises a passage opening for the key (having an open or closed profile) provided with a first portion substantially closely following or comprising the area of the key passage port and a second portion confining the shield. In case of normal use of the lock, the anti- manipulation plate 14 is usually disposed to a height in which the upper portion 19a of slot 19 is aligned with opening 7 and is extended enough to closely follow or comprise such a passage port (Fig. 3) . If the anti- manipulation plate 14 lifts up as a result of raising of the safety plates 4 and possibly also due to the action of the safety pin 13, the lower portion 19b comes close to opening 7 (Fig. 4) so that in at least one obstruction position of the anti-manipulation plate the key passage port is at least partly obstructed by a portion of the anti-manipulation plate 14 defining said shield . Generally, the shaped profile 16 and safety pin 13 form translation cam means operating between the anti- manipulation plate 14 and bolt member 12 to bring the shield S to at least one further obstruction position in which the passage port is further at least partly obstructed by the shield.

In general, the safety lock according to the present invention can comprise translation cam means operating between the shield S and the bolt member 12 to bring the shield S to at least a further obstruction position in which the passage port is further at least partly obstructed by the shield.

Operation of the safety lock will be hereinafter described with reference to an illicit opening attempt using instruments of the new generation.

With reference to Fig. 3, a tensioning device similar to that denoted at T in Figs. 9-11 is inserted into opening 7 tensioning the bolt member 12 against the safety plates 4 and the anti-manipulation plate 12 in the opening direction of the lock (arrow A) .

Subsequently, a rod provided with pins at one end is inserted, which rod raises all plates to the maximum lifting-up position. The rod is similar to that denoted at ST in Figs. 9-11.

By causing oscillation of the manipulation instrument an attempt is made to find the double-sided profile of the key blade at the first key turn.

The anti-manipulation plate 14 (or generally the shield S) is raised by the manipulation instrument and the safety plates 4, thus partly obstructing the key passage port. Possibly partial sliding of the bolt member 12 according to arrow A causes further raising of the anti-manipulation plate 14 and further obstruction of the passage port (Fig. 3) . This involves locking of the manipulation instrument inside the lock, so that the instrument cannot make the key turn and can be released only by proposing the initial conditions again and therefore setting to zero the position of the pins on the rod, which will bring about, as a result, impossible detection of the double-sided profile of the key directly from the safety plates.

As an alternative to the above, shield S can be mounted inside the safety lock in such a manner that it is shiftable even due to movement of the bolt member alone from the closed position to the open position causing the translation cam means to intervene.

As an alternative to the above, the constraint means between the anti-manipulation plate and the safety plates can be different, and lower wings on the safety plates adjacent to the anti-manipulation plate can be for example provided.

In accordance with a possible embodiment of the present invention, with reference to Fig. 1 or 3, the safety pin 13 has at least one recess 20 facing away from the lock pins (or the like), not shown.

With reference to Fig. 3, the recess 20 is for example formed with inclined cuts so as to create an upper hook-shaped portion 20a and a lower hook-shaped portion 20b. Alternatively the recess is of rectangular shape.

One of the safety plates 4 as shown for example in Fig. 5 will be described hereinafter in detail. The features described in the following can be present in at least one of the safety plates. If these features are present in all safety plates of the lock, the description made for the plate in Fig. 5 will be also valid, by analogy, for different plates.

Denoted at 21 is a tooth of the toothed profile defining window 8. In the example of the safety plate shown in Fig. 5 a lower tooth is alternated with an upper tooth. Alternatively, a safety plate can only comprise either upper teeth (see the second and fifth safety plates in Fig. 1 starting from cover 3) or lower teeth . Each tooth 21 defines a passage groove 9.

At least one tooth (preferably the tooth corresponding to the first opening turn) comprises a recess 22 similar to that provided on the safety pin 13, for example. Recess 22 faces the bolt pins (or the like), not shown. The recess 22 is formed with cuts, for example inclined, so as to create at least one upper hooking portion 22a. In general, the safety lock comprising a safety plate as previously described is provided with hooking means operating between the bolt member 12 and at least one safety plate 4, as a result of a thrust illicitly produced on the bolt member 12 (arrow A - Fig. 3) .

In particular, the hooking means comprises at least one hook-shaped portion formed in the safety pin 13 of the bolt member 12, the hooking opening of which is preferably oriented according to the opening direction of the bolt member. Advantageously, two hook-shaped portions are formed: an upper hook-shaped portion and a lower hook-shaped portion.

In addition, the hooking means comprises a hook-shaped portion formed in a tooth 21 of window 8 of the safety plate 4, preferably the hooking opening of which is oriented according to the closing direction of the bolt member. In particular, the opening of the hooking portion of the safety plate faces the bolt pins (or the like), not shown.

Advantageously, at least one upper hooking portion 22a is provided. In accordance with a possible embodiment, the safety plate as previously described further comprises means suitable to enable rotation of the safety plate 4 in a plane parallel to the safety plate itself, when the safety plate is in a position of maximum lifting-up of the safety plate itself. In particular, it is provided that at least one of the two slide slots 5, preferably the lower slot, be adapted to enable rotation/inclination of the safety plate in the plane of the safety plate itself in the maximum lifting-up position. In particular, at least one slide slot 5, preferably the lower slot, comprises an enlarged portion 23 in which pin 6 can be positioned enabling rotation of the safety plate in its own plane.

Described hereinafter is operation of the safety lock comprising a safety plate as previously described, with reference to an illicit opening attempt using instruments of the new generation.

The tensioning device T tensions the bolt member 12 against the safety plates 4 and the anti-manipulation plate 12 in the opening direction of the lock (arrow A) .

Subsequently, a rod ST provided with pins at one end is inserted, which rod raises all plates to the maximum lifting-up position. By causing oscillation of the burglary instrument, an attempt is made to find the pattern of the double-sided key profile at the first key turn.

Oscillation of the burglary instrument and simultaneous thrust on the lock member cause hooking between the safety pin and the corresponding tooth of the safety plate .

In addition, the pusher discharges its thrust on the safety plate that, due to the enlarged portion 23 of the lower slide slot, can rotate in its own plane further helping in hooking the safety pin to the tooth of the safety plate. The safety plate is therefore locked to a height that does not correspond to the opening height so that the burglary instrument cannot detect the key double-sided profile . In general terms, the present invention relates to a safety lock 1 comprising:

- a frame defining a passage port of a key in the lock,

- a bolt member 12 movably mounted on the frame and shiftable by rotation of the key in the lock between a first position corresponding to an opening condition of the lock and a second position corresponding to a closed condition of the lock;

- at least one safety plate 4 slidably mounted on the frame and shiftable by rotation of the key in the lock to a movement-enabling position of the bolt member 12, wherein said key passage port is projected right through the lock identifying a free passageway for introduction of the key transversely of at least one safety plate 4,

comprising a shield S movably mounted on the frame and shiftable, due to displacement of the at least one safety plate 4, to an enabling position and/or of the bolt member 12 to the open position, between a permission position for passage of the key or other, in which said passage port is clear, and at least one obstruction position in which said passage port is at least partly obstructed by said shield S.

In accordance with the above stated aspect, the lock can be accomplished according to one or more of the following embodiments.

In accordance with a possible embodiment, the shield S is formed with an anti-manipulation plate 14 disposed parallel to the at least one safety plate 4.

In accordance with a possible embodiment, the anti- manipulation plate 14 comprises a passage opening 19 for the key provided with a first portion 19a that substantially closely follows or comprises the area of the key passage port and a second portion 19b confining said shield S.

In accordance with a possible embodiment, the passage opening is a passage slot 19 delimited by a closed profile P in which said second portion 19b has at least one smaller size than the corresponding size of the passage port in the plane of the anti-manipulation plate .

In accordance with a possible embodiment, the second portion 19b has an increasing width L starting from a lower edge, in which it is smaller than the width L' of the passage port, until opening into the first portion in which it is as large as, or larger than the width of the passage port.

In accordance with a possible embodiment, the anti- manipulation plate 14 comprises at least one displacement wing 18 extending transversely of the planar extension of the anti-manipulation plate itself, preferably two displacement wings 18 extending away from the plane of the anti-manipulation plate 14 towards opposite directions, said at least one or two wings arranging themselves transversely of at least one safety plate 4 parallel to the anti-manipulation plate 14 so that, due to movement of the safety plate 4, the safety plate 4 drags along the anti-manipulation plate 14.

In accordance with a possible embodiment, translation cam means is provided which operates between said anti- manipulation plate 14 and bolt member 12 to bring said shield S to at least another obstruction position in which said passage port is further at least partly obstructed by said shield.

In accordance with a possible embodiment, the anti- manipulation plate 14 comprises a window 15 for passage of a safety pin 13 of the bolt member 12, and the window 15 has at least one inclined profile 16 interacting with said safety pin 13 on passage between the second position and first position of the belt member 12.

In accordance with a possible embodiment, the inclined profile 16 terminates at a support position of the anti-manipulation plate 14 on the bolt member 12, an apex 17 for example.

In accordance with a possible embodiment, translation cam means is provided which operates between said shield S and bolt member 12 to bring said shield to at least one obstruction position in which said passage port is at least partly obstructed by said shield.

In accordance with a possible embodiment, the shield S has at least one profile S' that is substantially inclined and is adapted to generate a growing obstruction of the key passage port as a function of the shield position.

Claims

C L A I M S

1. A safety lock (1), comprising:

- a frame defining a port for passage of a key into the lock,

- a bolt member (12) movably mounted on the frame and shiftable by rotation of the key in the lock between a first position corresponding to an open condition of the lock and a second position corresponding to a closed condition of the lock,

- at least one safety plate (4) movably mounted on the frame and shiftable by rotation of the key in the lock to a position enabling movement of the bolt member (12) ,

wherein said passage port of the key is projected right through the lock and identifies a free passageway for introduction of the key transversely of the at least one safety plate (4),

characterised in that it comprises a shield (S) movably mounted on the frame and shiftable, due to displacement of the at least one safety plate (4) to an enabling position and/or of the bolt member (12) to an open position, between a permission position for passage of the key or other, in which said passage port is clear, and at least one obstruction position in which said passage port is at least partly obstructed by said shield (S),

wherein said shield (S) is formed with an anti- manipulation plate (14) disposed parallel to the at least one safety plate (4), and

wherein said safety lock comprises translation cam means operating between said anti-manipulation plate (14) and bolt member (12) to bring said shield (S) to at least a further obstruction position in which said passage port is further at least partly obstructed by said shield.

2. A safety lock (1) as claimed in claim 1, wherein said anti-manipulation plate (14) comprises a passage opening (19) for the key provided with a first portion

(19a) that substantially closely follows or comprises the area of the key passage port and a second portion

(19b) confining said shield (S) .

3. A safety lock (1) as claimed in claim 2, wherein said passage opening is a passage slot (19) delimited by a closed profile (P) in which said second portion (19b) has at least one size that is smaller than the corresponding size of the passage port in the plane of the anti-manipulation plate.

4. A safety lock (1) as claimed in claim 3, wherein said second portion (19b) has a width (L) increasing from a lower edge in which it is smaller than the width (L') of the passage port, until opening into the first portion in which it is as large as, or larger than the width of the passage port.

5. A safety lock (1) as claimed in one or more of claims, wherein said anti-manipulation plate (14) comprises at least one displacement wing (18) extending transversely of the planar extension of the anti- manipulation plate itself, said at least one wing being arranged transversely of at least one safety plate (4) parallel to the anti-manipulation plate (14), so that, due to a movement of the safety plate (4), the safety plate (4) drags along the anti-manipulation plate (14) .

6. A safety lock (1) as claimed in claim 5, wherein said anti-manipulation plate (14) comprises two displacement wings (18) extending away from the plane of the anti-manipulation plate (14) towards opposite directions .

7. A safety lock (1) as claimed in one or more of the preceding claims, wherein said anti-manipulation plate (14) comprises a window (15) for passage of a safety pin (13) of the bolt member (12), and wherein said window (15) has at least one inclined profile (16) interacting with said safety pin (13) during passage between the second position and the first position of the bolt member (12) .

8. A safety lock (1) as claimed in claim 7, wherein said inclined profile (16) terminates at a support position of the anti-manipulation plate (14) on the bolt member (12) .

9. A safety lock (1) as claimed in claim 8, wherein said inclined profile (16) terminates with an apex

(17) .

10. A safety lock (1) as claimed in one or more of the preceding claims, comprising translation cam means operating between said shield (S) and bolt member (12) to bring said shield to at least one obstruction position in which said passage port is at least partly obstructed by said shield.

11. A safety bolt (1) as claimed in one or more of the preceding claims, wherein said shield (S) has at least one substantially inclined profile (S') adapted to generate a growing obstruction of the key passage port, as a function of the shield position.