EP0376867B1 - Lock with an additional safety block - Google Patents

Abstract

The key (1) comprises a shank, the cross-section of which is cross-shaped and terminates in a flat double bit cut to form variations corresponding to the combination of the safety block (2) and covered in its middle, on its two faces, by two ribs extending the shank of the key (1). The safety block (2) comprises an entry washer (7) which is displaceable in rotation and in which is formed an orifice (8) of reduced dimensions, the shape of which reproduces that of the cross-section of the key (1) in the region of the bit, and which has in its middle a double widening (9) for the passage of the ribs extending the shank of the key (1) and, immediately to the rear of this entry washer (7), a safety washer (11) forming a guard which closes off the key entrance (8) once the key (1) has rotated in the safety block (2) through a particular predetermined fraction of a revolution, this safety washer (11) having in its middle an orifice (12) allowing the passage of the key (1) and possessing a central widening (13) sufficient to allow the free rotation of the shank (3) of the key (1). <IMAGE>

Description

The present invention relates to a lock and key device comprising a key of a new type, the rod of which is in cross section, intended to cooperate with a security lock of the type comprising an added safety block.

To date, a certain number of security locks are known implementing a security block which can either be integrated into the lock, or attached to it. In the latter case, the function of the safety block is to prohibit access to the lock unless the key corresponding to its combination is used.

Among the known safety blocks, the most commonly used include a rotor mounted movable in rotation in a stator. In this case, the rotor can be rotated by a key, the end of which has a cutout corresponding to the combination of the lock.

Other safety blocks, less widespread, include a stack of washers, each of which has a very specific internal cutout, the relative position of these washers determining the combination of the lock at the same time as the rotation stroke of the key.

This last type of safety block is the more often associated with a round key, that is to say a key whose cross section of the rod is circular. In this case, the end of the key is cut to correspond to the combination of the block, defined by the relative position of the washers.

This type of key has the disadvantage of having a fairly large circular section, so that the entrance to the corresponding safety block has a relatively large opening, and does not oppose a sufficient obstacle to an attempted break-in.

• a) la clé comporte une tige dont la section est en forme de croix et se termine par un panneton double et plat, symétrique par rapport à l'axe de la clé, et découpé en variures correspondant à la combinaison du bloc de sûreté, le panneton étant recouvert en son milieu, sur chacune de ses deux faces d'une nervure prolongeant la tige de la clé, la tige étant constituée d'une barre plate surmontée sur chaque face, en leur milieu, de ladite nervure ayant une section parallélépipédique;
• b) le bloc de sûreté comporte une rondelle d'entrée déplacable en rotation dans laquelle est ménagée une ouverture de dimensions réduites dont la forme en croix épouse celle de la section de la clé au niveau du panneton, présentant en son milieu un double élargissement pour le passage des nervures, la forme de cet élargissement reproduisant la section des nervures, et immédiatement en arrière de la rondelle d'entrée, une rondelle de sécurité formant cache qui obture l'entrée de clé une fois que la clé a tourné dans le bloc de sûreté d'une certaine fraction de tour prédéterminée, cette rondelle de sécurité comportant en son milieu une ouverture permettant le passage de la clé et présentant un élargissement central suffisant pour permettre la rotation libre de la tige de la clé.

The object of the present invention is to remedy this drawback by proposing a key of a new type associated with a safety block, the advantage of the assembly residing on the one hand in the reduced dimensions of the key entry of the safety block and secondly in the installation of a safety washer behind the key entry, once the latter has turned a certain fraction of a turn in the safety block.
The present invention thus relates to a lock and key device, of the type comprising a safety block attached to the lock and a key whose bit has variations corresponding to the combination of said safety block, characterized in that:

• a) the key comprises a rod, the cross section of which is in the shape of a cross and ends with a double and flat bit, symmetrical with respect to the axis of the key, and cut into variations corresponding to the combination of the safety block, the the bit being covered in the middle, on each of its two faces with a rib extending the rod of the key, the rod consisting of a flat bar surmounted on each face, in the middle, of said rib having a parallelepiped section;
• b) the safety block has an entry washer displaceable in rotation in which is made an opening of reduced dimensions whose cross shape matches that of the section of the key at the bit, having in its middle a double widening for the passage of the ribs, the shape of this widening reproducing the section of the ribs, and immediately behind the entry washer, a safety washer forming a cover which closes the key entry once the key has turned in the safety block by a certain predetermined fraction of a turn, this safety washer having in its middle an opening allowing the passage of the key and having a central enlargement sufficient to allow free rotation of the key rod.

As is usual in this type of safety block with washers, the rotation of the key by a certain fraction of a turn causes, at the exit of said block, the rotation of a set of keys and cams which releases the exit , authorizing the passage of the key and its access to the lock on which said safety block is attached.

The reduced dimensions of the key entry of the safety block according to the invention are authorized by the profile which the key according to the invention has at its end, the double and flat bit which it comprises being thin, likewise than the two ribs which extend the stem of the key and which overcome it on both sides.

It follows that the key entry of the safety block according to the invention has approximately the shape of a rectangle of small width comprising in its middle two symmetrical enlargements of small dimensions for the passage of these two ribs.

The security resulting from the reduced dimensions of the key entry of the safety block according to the invention is further increased by the presence, in said safety block, immediately behind the entry washer movable in rotation under the action. of the key, of a safety washer forming a cover which has the function of closing off the entry of the key when the latter has turned in the safety block of the predetermined fraction of a turn, which frees the exit from said block by authorizing passing the key.

The safety washer placed behind the inlet washer of the safety block is advantageously extended by a flat ring of a certain thickness surrounding said inlet washer.

The key entry formed in the entry washer is, as has already been said, of reduced dimensions, affecting the shape of the profile of the key at the bit and having two enlargements for the passage of the ribs extending the key shank.

These ribs advantageously have an approximately square section, and the enlargements in question have a corresponding shape, so as to allow the ribs of the key rod to drive the inlet washer in rotation.

On the other hand, the safety washer positioned immediately behind the inlet washer has an opening widened at its central part so as not to give grip to the ribs of the key rod.

The inlet washer of the safety block according to the invention further comprises, arranged in its thickness, regularly spaced cylindrical housings, arranged converging towards the center of the washer and opening at its periphery, these housings each containing a spring intended to apply a ball against the wall of the flat ring extending the safety washer.

Housing of the same number is also provided in this ring to receive the balls of the inlet washer, so as to lock the latter in the two positions that it is capable of adopting.

The safety washer is itself held in position by means of orifices, most often two in number, formed on its surface for the passage of the screws which secure all of the washers constituting the safety block.

According to a preferred embodiment of the device according to the invention, the number of housings formed in the inlet washer as well as in the ring extending the safety washer is four, so that two consecutive housings of the washer entry are positioned at right angles to each other. In this case, the key's rotational stroke is limited to a quarter of a turn, the key being positioned at a quarter of a turn.

The present invention will be better understood on reading the description which follows and which refers to the drawing attached, it being understood that this description does not have any limiting character with respect to the invention.

• la figure 1 représente une vue de dessus d'une clé selon l'invention.
• la figure 2a représente une vue en coupe, selon la ligne I-I, de la tige de la clé représentée à la figure 1.
• la figure 2b représente une vue en coupe, selon la ligne II-II, de la même clé.
• la figure 3 représente une vue de face, à plus grande échelle, de la rondelle d'entrée d'un bloc de sûreté selon l'invention.
• la figure 4 représente une vue en coupe, selon la ligne III-III, de la rondelle d'entrée représentée à la figure 3.
• la figure 5 représente une vue de face de la rondelle de sécurité du même bloc de sûreté.
• la figure 6 représente une vue en coupe, selon la ligne IV-IV, de la rondelle de sécurité représentée à la figure 5.

In the attached drawing:

• Figure 1 shows a top view of a key according to the invention.
• FIG. 2a represents a sectional view, along line II, of the rod of the key shown in FIG. 1.
• Figure 2b shows a sectional view, along line II-II, of the same key.
• FIG. 3 represents a front view, on a larger scale, of the inlet washer of a safety block according to the invention.
• FIG. 4 represents a sectional view, along line III-III, of the inlet washer shown in FIG. 3.
• FIG. 5 represents a front view of the safety washer of the same safety block.
• FIG. 6 represents a sectional view, along line IV-IV, of the safety washer shown in FIG. 5.

If we refer to Figure 1, we see the key 1 having a rod 3 cross section terminated at its end by a bit 4 covered in the middle, on both sides, by two ribs 5 extending the rod 3. bit 4 is symmetrical with respect to the axis of key 1 and has variations 4 ′ which are also symmetrical.

If we refer to Figure 2a, we see the cross section of the rod 3 of the key 1, highlighting that it is formed of a flat bar 6 surmounted on each of its faces, in the middle, by two ribs 5 with square section.

Figure 2b shows the profile of the key 1 at the bit 4, with the rib 5 of the rod 3 which partially covers it in the middle.

If we now refer to Figure 3, we see the entrance to the safety block 2 consisting of a washer 7 provided in the middle of an opening 8 whose shape corresponds to that of the section of the key 1 shown in Figure 2b: the opening 8 thus has the shape of a rectangle having in its middle two enlargements 9 symmetrical for passage ribs 5.

The inlet washer 7 is immobilized in rotation by means of four balls, not shown, placed in four housings 10 formed in the thickness of the washer 7 and opening at its periphery, the four balls being associated with four springs, also not shown, which tend to eject them out of the housings 10.

If we refer to Figure 4, we can clearly see the opening 9 of the inlet washer 7 and the housings 10 housing the ball-spring assemblies.

If we now refer to Figure 5, we see the safety washer 11 having in its middle an opening 12 for the passage of the key 1, said opening 12 having a central enlargement 13 sufficient to allow free rotation of the rod 3 of key 1.

The washer 11 is surmounted by a ring 16 pierced with four holes 14 for receiving the balls in one or the other of the two possible positions of the inlet washer 7. Two holes 15 formed in the bottom of the washer 11 allow the passage of two screws, not shown, which secure all of the washers constituting the safety block 2.

FIG. 6 clearly shows the safety washer 11 pierced with two holes 15 for the passage of the fixing screws, and surmounted by the ring 16 pierced with holes 14 intended to receive the balls placed in the housings 10 of the inlet washer 7.

The operation of this device is as follows: the key is inserted into the safety block 2, where its end comes into abutment on the exit face of the block. A quarter turn key rotation results in the same rotation of the inlet washer 7, the inlet 8 of which is then closed off by the safety washer 11 placed immediately behind it.

Simultaneously, the set of cams and keys arranged at the outlet of the safety block 2 is rotated, freeing the passage of the key 1 and authorizing its access to the lock on which the safety block 2 is attached.

As has already been said, closing the key entry with the safety washer enhances the security of the device according to the invention, access to the mechanism of the safety block being completely prohibited when the key has operated the opening of the safety block.

This security increases that inherent in the reduced dimensions of the key entry, which constitutes an obvious obstacle to attempted break-ins.

Claims (3)

1. Lock and key device of the type including a safety block attached to the lock and a key on which the web has divisions corresponding to the combination of the said safety block, characterised in that:

   a) the key (1) has a shank (3), the cross section of which is cruciform and terminates in a double flat web (4), symmetrical with respect to the axis of the key and cut into divisions (4') corresponding to the combination of the safety block (2), the web (4) being covered at its middle, on each of its two faces, with a rib (5) extending the shank (3) of the key (1), the shank (3) consisting of a flat bar (6) surmounted on each of its faces, in their middle, with the said rib (5) with a parallelepipedal cross section;

   b) the safety block (2) has an entry washer (7), movable in rotation, in which a small opening (8) is formed, the cruciform shape of which matches that of the cross section of the key (1) at the level of the web (4), having in its middle a double enlargement (9) for the ribs (5) to pass through, the shape of this enlargement (9) reproducing the cross section of the ribs (5), and, immediately behind the entry washer (7), a Security washer (11) forming a cover which closes off the key entry (8) once the key (1) has turned in the safety block (2) by a certain predetermined fraction of a turn, this security washer (11) having in its middle an opening (12) allowing the key (1) to pass and having a central enlargement (13) sufficient to allow the free rotation of the shank (3) of the key (1).
2. Device according to Claim 1, characterised in that the security washer (11) is extended, at its face situated on the entry washer (7) side, by a flat ring (16) having at least two evenly spaced orifices (14) for receiving balls placed in at least two cylindrical housings (10) formed in the entry washer (7), the said housings (10) being evenly spaced and convergent towards the centre of the washer (7) and the balls being associated, in these housings (10), with springs which press them against the wall of the ring (16) fitting on top of the security washer (11), the orifices (14) in the said ring (16) receiving the balls placed in the housings (10) in one or other of the two possible positions of the entry washer (7)
3. Device according to Claim 2, characterised in that the entry washer (7) has four cylindrical housings (10) and the ring (16) fitting on top of the safety washer (11) four corresponding orifices (14), the rotational travel of the key (1) being then limited to a quarter of a turn and its rotation causing the rotation, also by a quarter of a turn, of the entry washer (7) driven by the ribs (5) on the shank (3) of the key (1), the key entry (8) in the safety block (2) being then closed off by the security washer (11), this rotation being accompanied by the opening of the key exit in the safety block (2) allowing the key (1) to pass and have access to the lock to which the safety block (2) is attached.

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