Safety lock for household doors and similar

Abstract

 A safety lock is described that is equipped with a removable core provided with means of rekeying that permit the lock to be adapted to a new key.

Description

[0001] The present invention refers to safety locks for household doors and similar of the type including:

• a housing, with a keyhole for inserting a double bitted key,
• at least one bolt arranged inside the housing and projecting from one side of the housing,
• a plate connected to the bolt and having a set of teeth that can be engaged by the key for controlling the movement of the bolt, and
• a pack of safety plates inside the housing, presenting apertures with notched edges through which a stop pin carried by the bolt plate passes, the said safety plates each having an engaging edge for a corresponding portion of the key and moveable at right angles to the direction of the bolt's movement, due to the engagement effect of the key against the action of elastic means of return, towards a position in which the apertures define a corridor for the free passage for the stop pin.

[0002] The applicant has produced and commercialised a double bitted lock of the above indicated type for some time now, in which the pack of safety plates and the relative elastic means of return are carried on an auxiliary frame, so as to constitute a core fixed to the housing in a removable manner, in which the keyhole for inserting the key is also obtained from the said removable core, and in which the said bolt plate is also mounted on the auxiliary frame such that it is free to slide, this plate being connected to the bolt in a manner such that it can be uncoupled.

[0003] With a view to further improving the above specified device, the object of the present invention is, according to a first form, a double bitted lock, equipped with a removable core, characterized in that the said removable core is provided with means of rekeying, to adapt the lock to a key with a different profile.

[0004] In the lock in accordance with the invention, each safety plate is composed of two half-plates, with one carrying the edge for key engagement and the other the aperture for stop pin engagement. The said means of rekeying are suitable for repositioning and blocking the said half-plates together in various relative positions, for the purposes of adapting the plates in question to a key with a different profile.

[0005] Thanks to the above characteristics, the lock in accordance with the invention combines the advantage of a removable core, which allows the safety mechanism of the lock to be substituted without the need of changing the entire lock, with the advantage of being able to perform the rekeying of the removable core, to adapt the lock to a key with a different profile, without the need of substituting the core.

[0006] According to a second form, the present invention is intended for means of rekeying that are provided in a lock in accordance with the invention, independently of the fact that this lock is equipped with a removable core or instead possesses a conventional structure without a removable core. As already indicated, in accordance with the invention, each of the safety plates is composed of two half-plates, respectively carrying the engagement edge for the key and the engagement aperture for the safety pin, which can be repositioned in various relative positions. The means of rekeying include means for temporarily blocking a first type of half-plates in position, the half-plates that carry the engagement apertures for the safety pin for example, and means for moving, in the direction at right angles to that of the bolt's movement, the second type of half-plates, those carrying the engagement edges for the key for example, whilst the first type of half-plates are kept temporarily blocked.

[0007] Preferably, the repositioning of the second type of half-plates with respect to the first type of half-plates is directly achieved via the new key to which the lock must be adapted, engaging the second type of half-plates with this new key, whilst the first type of half-plates are kept temporarily blocked.

[0008] Additional characteristics and advantages will be will become clear from the description that follows with reference to the enclosed drawings, supplied purely by way of a non-limitative example, where:

• Figure 1 is a perspective view of a first form of embodiment of the lock in accordance with the invention,
• Figure 2 is a partially exploded perspective view of the lock in Figure 1,
• Figure 3 is a frontal view of the removable core forming part of the lock in Figures 1 and 2,
• Figure 4 is a rear perspective view of the block carrying the guide passage for inserting the key and fixed to the front part of the removable core of the lock,
• Figure 5 is a rear perspective view of a plate forming part of the means of rekeying the lock, the position of which is controlled via a control member located on the front of the said block,
• Figure 6 is a rear view of the said control member,
• Figures 7 and 8 are cross-sectional views that show the control member in two different operative states,
• Figure 9 is a sectional front view of the removable core of the lock in accordance with the invention, in the normal usage state,
• Figure 10 is s front view of the removable core that draws attention to how the plate in Figure 5 is mounted,
• Figures 11, 12 and 13 are similar views to that in Figure 9 which show different operative states of the core during the lock's rekeying phase,
• Figure 14 is a perspective view of the rear part of the removable core, with the plate destined to be connected to the bolt of the lock,
• Figure 15 is an exploded perspective view of the lock in the previous Figures, and
• Figure 16 is a perspective view of a variant of the lock in Figure 1.

[0009] In Figures 1 and 2, reference number 1 indicates a complete safety lock for household doors and similar. The lock 1 includes a housing 2 of sheet metal, from which the bolt protrudes, the latter being composed of, for example, a number of steel pins 3 all carried by the same mobile plate inside the lock. According to the known technique, the entire operating mechanism of the bolt 3 is contained in a removable core 4, the front of which carries a block 50 with a guide passage 60 for the insertion of a key of the double bitted type. Figure 2 shows the removable core 4 in the extracted position.

[0010] With reference to Figure 15, the core 4 includes an auxiliary frame constituted by two sheet metal plates 4a and 4b, which are mutually parallel and set apart. Always with reference to Figure 15, reference number 40 indicates an additional plate that, when the core 4 is mounted inside a lock, is destined to be directly or indirectly connected to the bolt plate of the lock, thereby resulting operatively associated with the bolt. The bolt plate 40 carries a set of teeth 5 for engagement with the double bitted active portion (indicated as C in Figure 9) of the key. The bolt plate 40 also carries a safety pin 6. The bolt plate 40 is mounted such that it can slide inside the removable core 4 in the bolt's direction of movement.

[0011] Always according to a known technique, the removable core 4 also includes a pack of safety plates 7 arranged between the two plates 4a and 4b. Each safety plate presents an edge 7 for engaging the double bitted active portion of the key, and an aperture with notched edges 7b for engaging the safety pin 6.

[0012] In the normal operating state, the above described lock functions in the following manner. The active portion of the key is inserted inside the lock by making it pass through the guide passage 60 in the block 50, and a keyhole 61 made on the front plate 4a. Once the key is inserted, its rotation causes the edges of the double bitted portion to engage with the edges 7a of the safety plates 7. In this way, the safety plates 7 are moved in a direction at right angles with respect to the bolt's direction of movement (i.e. vertically upwards with reference to Figure 9) against the action of springs (not visible in the drawings) that apply a force in the direction indicated by arrow 8 in Figure 9 against an appendage 10 of each safety plate. In this way, each safety plate is set in a position determined by the corresponding portion of the profile of the key that engages the relative edge 7a, such that the various apertures 7b of all the plates 7 leave an open corridor for the passage of the safety pin 6 carried by the bolt plate 40. The authorized key is thus capable of continuing its rotation and determining the horizontal movement (with reference to Figure 9) of the bolt plate 40, following its engagement against the set of teeth 5.

[0013] As already indicated in the foregoing, according to a first form, the invention consists in having arranged means for rekeying the lock on the removable core, that is means that allow the lock to be adapted to a key with a different profile. This requirement arises every time that it is wished to re-establish the security of the lock, after the key has been at the disposition of strangers for example.

[0014] Below, an example of the preferred form of embodiment of the said means of rekeying will be described. Nevertheless, it is evident that these means of rekeying could be realized in any other kind of way, the invention consisting in the fact of providing the means of rekeying on the removable core of a lock. From a different point of view, the invention also protects the specific form of embodiment of the means of rekeying that are described herein, independently of the fact that they adopted on the removable core of a lock, or on a traditional lock without a removable core.

[0015] Turning now to the specific form of embodiment of the means of rekeying that are illustrated in the enclosed drawings, it is necessary first of all to note that each of the safety plates 7 is constituted by two half-plates 71 and 72 (clearly distinguishable in Figure 11) with one carrying an aperture 7b and the other the edge 7a for engagement with the key and presenting reciprocally engaging, facing sets of teeth 73 which allow the two half-plates 71 and 72 to be repositioned and blocked together in different relative positions with reference to the direction at right angles to the bolt's direction of movement (i.e. with respect to the vertical direction in Figures 9-13).

[0016] In the case of the example of embodiment that is illustrated in the drawings, the rekeying of the removable core of the lock in accordance with the invention is achieved in the following manner.

[0017] With reference to Figure 10, the original key is inserted in the lock and turned to the half-turn position illustrated in Figure 10, so as to raise the safety plates 7 in the direction A (Figure 10) against the action of the return springs (represented by the arrow 8). In this way, the key also engages the set of teeth 5 of the bolt plate 40, causing a small movement to the right (with reference to the Figures) of the latter. Due to the effect of the combined movement consisting of the raising of the safety plates 7 and the small movement of the bolt plate, the safety pin 6 finds itself in the position illustrated in Figure 11, in which it is received in an end slot of the apertures 7b, thereby preventing movement of the half-plates 71 in the direction A. In this phase, the plates are kept in the said position by continuing to manually hold the active part C of the key in the position illustrated in Figures 10 and 11, against the action 8 of the return springs.

[0018] Keeping the key in the said half-turn position, the half-plates 72 are moved away to the left (Figure 11) from the half-plates 71 by acting with a screwdriver at the top of a revolving control member 90 situated on the front of the block 50. As shown in Figures 4 and 6-8, a screwdriver 100 can be inserted into a respective seat present on the revolving control member 90 to initially press in the axial direction of the member 90, against the action of a return spring 91, to be able to then rotate the said member around an axis 92. The control member 90 presents an engagement tooth 93 guided in an arched slot 94 on the block 50 and engaged in a slot 95 of a plate 96 that is guided on the structure of the core 4 in a direction parallel to the bolt's direction of movement and which carries an auxiliary safety pin 97.

[0019] Returning to the previously described phase, while the key C is held in the half-turn position to keep the safety pin 11 in the position illustrated in Figure 11, the control member 90 can be engaged with a screwdriver 100 and turned to move the plate 96 to the left, to a position in which it causes, via its two pins 96A that run through the half-plates 72, the moving away of the latter (Figure 11). In this way, the auxiliary safety pin 97 is brought to the position illustrated in Figure 11, inside a corresponding aperture 98 made in each of the half-plates 71, and thereby blocking these half-plates in the aforesaid state. A this point, on extracting the key, the half-plates 72 return to the start position, pushed by the return springs (the action of which is indicated by the arrow 8). At the same time, the auxiliary safety pin 97 is blocked in position by an oscillating lever 110 (Figure 14), mounted to swivel around 111 on the plate 4b, no longer held following engagement of the key against a catch 112. An aperture 113 that is present in the oscillating lever 110 is thus aligned above the auxiliary stop pin 97 and so prevents any erroneous movement of the half-plates. The lock thus finds itself on the state illustrated in Figure 12. At this point, to proceed with the rekeying, the new key is inserted into the lock, the former having a different profile to which the lock must be adapted. The lock is actioned again as before with the new key, keeping the key in position. In this way, following engagement of the key with the catch 112, the lever 110 is moved again and the auxiliary safety pin 97 is thus free to return to its normal position. The half-plates 72 follow the active part C^* of the new key (Figure 13) each one arranging itself in a position corresponding to the shape of the portion of the key's profile that engages it. In this state, the screwdriver 100 is used again on the control member 90 in order to bring the half-plates 72 back together with the half-plates 71 again. The pair of half-plates thus reengage with each other in a new relative position with respect to the previous one, suitable for permitting the lock to be actioned with the new key. In this way, rekeying of the lock has been performed.

[0020] Naturally, nothing prevents the adoption of the above described means of rekeying also in a traditional type of lock, without a removable core.

[0021] Figure 16 illustrates a variant of Figure 1 that is functionally identical but presents a block 50 that is circular in shape.

[0022] Naturally, the principle of the invention being understood, the constructional details and forms of embodiment could be extensively changed with respect to that described and illustrated by way of example without leaving the scope of the present invention.

Claims

1. A safety lock for household doors and similar, of the type including:

- a housing (2), with a keyhole for inserting a double bitted key,

- at least one bolt (3) arranged inside the housing (2) and projecting from one side of the housing,

- a plate (40) connected to the bolt (3) and having a set of teeth (5) that can be engaged by the key for controlling the movement of the bolt, and

- a pack of safety plates (7) inside the housing (2) presenting apertures (7b) with notched edges through which a safety pin (6) carried by the bolt plate (40) passes, the said safety plates (7) each having an engagement edge (7a) for a corresponding portion of the key and capable of moving at right angles to the direction of the bolt's movement, due to the engagement effect of the key against the action of elastic means of return (8), towards a position in which the apertures (7b) define a corridor for the free passage for the safety pin (6),

   in which the pack of safety plates (7) and the relative elastic means of return (8) are carried on an auxiliary frame (4a and 4b) so as to constitute a core (4) fixed to the housing (2) in a removable manner,
   in which the keyhole (61) for inserting the key is also obtained on the said removable core (4), and
   in which the said bolt plate (40) is also mounted on the said auxiliary frame (4a and 4b) such that it is free to slide, this plate (40) being connected to the bolt (3) in a manner such that it can be uncoupled,
   characterized in that the said removable core (4) is provided with means of rekeying, to adapt the lock to a key with a different profile.

2. A safety lock according to claim 1, characterized in that each safety plate (7) is composed of two half-plates (71 and 72) respectively carrying the engagement aperture (7b) for the safety pin (6), and the engagement edge (7a) for the key, and in that these half-plates (71 and 72) can be are mutually repositioned and blocked in different relative positions.

3. A safety lock according to claim 2, characterized in that the said means of rekeying include means for blocking half-plates (71) of a first type in position, whilst half-plates of the second type (72) are repositioned.

4. A safety lock according to claim 3, characterized in that the said means for repositioning the second type of half-plates (72) are constituted by the new key to which the lock must be adapted.

5. A safety lock according to claim 4, characterized in that the said means for blocking the first type of half-plates (71) provide an auxiliary safety pin (97) carried on an auxiliary plate (96) movable in a direction parallel to bolt's direction of movement via a control member (90), the said auxiliary safety pin (97) being suitable for engaging an auxiliary aperture (97a) on the first type of half-plate (71) and being blockable in that position via an additional locking lever (110).

6. A safety lock for household doors and similar, of the type including:

- a housing (2), with a keyhole for inserting a double bitted key,

- at least one bolt (3) arranged inside the housing (2) and projecting from one side of the housing,

- a plate (40) connected to the bolt (3) and having a set of teeth (5) that can be engaged by the key for controlling the movement of the bolt, and

- a pack of safety plates (7) inside the housing (2) presenting apertures (7b) with notched edges through which a safety pin (6) carried by the bolt plate (40) passes, the said safety plates (7) each having an engagement edge (7a) for a corresponding portion of the key and capable of moving at right angles to the direction of the bolt's movement, due to the engagement effect of the key, against the action of elastic means of return (8) towards a position in which the apertures (7b) define a corridor for the free passage for the safety pin (6),

   characterized in that it includes means of rekeying, for adapting the lock to a key with a different profile, said means of rekeying being formed as specified in one or more of the claims 2-5.

Drawing