Key, or key blank, for a cylinder lock

Abstract

 A key, or key blank, for a cylinder lock comprises a substantially elongated and flattened body (3) having two opposite main faces (31, 32), and a first engagement member (301) and a second engagement member (302), which are provided for co-operating with elements of the cylinder lock and are movable, within holes (306, 307) formed through the body (3) and giving out onto the main faces (31, 32), each between a position where it projects from a respective main face and a position where it is retracted within the respective hole. Provided within the body (3) are spring means (303) that push the first and second engagement members (301, 302) towards positions where they project from the main faces (31, 32) via a third control member (304) that is movable within the body (3) in a longitudinal direction of the body and that is pushed by the spring means (303) towards a position in which it sets itself between the first and second engagement members (301, 302) in such a way as to keep them in positions where they project. In a preferred embodiment, the two engagement members (301, 302) and the third control member (304) are constituted by balls.

Description

[0001] The present invention relates to keys and to key blanks for cylinder locks of the type comprising:

• a head;
• a substantially elongated and flattened body connected to the head and having two opposite main faces, at least one of which is configured for co-operating with elements of the cylinder lock;
• a first engagement member and a second engagement member, which are provided for co-operating with elements of the cylinder lock and are movable, within holes formed through said body and giving out onto said main faces, each between a position where it projects from a respective main face and a position where it is retracted within the respective hole; and
• spring means provided within said body that push said first and second engagement members towards positions where they project from said main faces.

[0002] Keys and key blanks of the type referred to above have been known and used for some time. A recent example of a key of this type is described in the document No. WO 2009/147660 A2.

[0003] The object of the present invention is to provide a key (and likewise a key blank) of the type referred to above that will be simple and fast to produce and assemble, will be functional in use, and will guarantee a high degree of safety also as regards duplication of the key.

[0004] With a view to achieving the above object, the subject of the invention is a key or key blank having all the characteristics that have been referred to at the start and further characterized in that the aforesaid spring means push the aforesaid first and second engagement members via a third control member, which is movable within said body in a longitudinal direction of said body and is pushed by said spring means towards a position in which it sets itself between said first and second engagement members in such a way as to keep them in positions where they project.

[0005] In the preferred embodiment, the aforesaid control member is mounted within an axial cavity of the aforesaid body formed starting from an end surface of the body opposite to the head of the key or of the key blank. Preferably, moreover, the aforesaid spring means are constituted by a helical spring provided within the aforesaid axial cavity, between the bottom of the cavity and the aforesaid control member.

[0006] Once again in the case of the preferred embodiment, the aforesaid first and second engagement members and the aforesaid control member are balls, even though there is not ruled out the possibility of said members having a different conformation. In particular, in the preferred embodiment, the aforesaid engagement members and the control member are balls of identical diameter.

[0007] According to a further characteristic, the body of the key or of the key blank is provided for defining arrest surfaces for the aforesaid first and second engagement members towards positions where they project. In one embodiment, the hole in which one of the two engagement members is movable gives out onto the respective main face with a conical portion, which defines the arrest surface for the aforesaid engagement member, whilst the rim of the other hole is permanently deformed (the material of the key is metal) for defining the arrest surface of the other engagement member.

[0008] Thanks to the above characteristics, the key of the invention guarantees an operation that is more efficient and reliable as compared to known solutions. The two engagement members are independent of one another, but notwithstanding this they are forced by the control member always to present a symmetrical movement, which prevents any of said members from displacing between the retracted position and the projecting position, unless the other member can perform a corresponding movement. Moreover, a duplication of the key can be obtained only starting from a key blank that is provided with the aforesaid elements, which guarantees the possibility of setting up a system for control of duplications through the provision of authorized centres that are provided with said key blanks.

[0009] Further characteristics and advantages of the invention will emerge from the ensuing description, with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

• Figure 1 is a schematic perspective view of a preferred embodiment of a key according to the invention;
• Figure 2 is a side view of a cylinder lock and of the key of Figure 1 that can be used in co-operation with said lock, with the key in the condition where it is extracted from the lock;
• Figure 3 is a cross-sectional view according to the line III-III of Figure 2;
• Figure 4 is a cross-sectional view and at an enlarged scale of the detail designated by IV in Figure 2;
• Figures 5-7 are views corresponding to those of Figures 2-4, which refer to a condition in which the key is only partially introduced into the lock, Figure 6 being a cross-sectional view according to the line VI of Figure 5 and Figure 7, showing at an enlarged scale a cross section of the detail designated by VII in Figure 5; and
• Figures 8-10 are views corresponding to those of Figures 2-4 and 5-7 that refer to the condition in which the key is completely introduced into the lock, Figure 9 illustrating a cross-sectional view according to the line IX-IX of Figure 8, and Figure 10 showing at an enlarged scale a cross-sectional view of the detail indicated by X in Figure 8.

[0010] With reference to Figure 1, the reference number 1 designates as a whole a preferred embodiment of a key according to the invention. The key 1 has a head 2 and an elongated and flattened body 3 connected at one end to the head 2 and having two opposite main faces 31, 32 configured for co-operating with elements of a cylinder lock 4. The body 3 has two longitudinal sides 33, 34 and an end surface 35.

[0011] According to a technique in itself known, both the main faces 31, 32 and the sides 33, 34 are provided with cavities and/or grooves designed to co-operate, in a way in itself known, with corresponding elements of the cylinder lock. A detailed description of an example of embodiment of a cylinder lock and a key designed to co-operate with the above lock is described, for example, in the document No. EP 1 019 601 B1, filed in the name of the present applicant.

[0012] In the ensuing description, and in the annexed drawings, the constructional details regarding the cylinder lock, as well as those regarding the surfaces, cavities, and/or grooves provided on the key for co-operating with the elements of the lock are not described or illustrated both in so far as they can be obtained in any known way and in so far as elimination of the majority of the aforesaid details from the drawings renders the latter more readily and easily understandable. For this reason, in the drawings only the main parts of the lock and of the key have been illustrated, as well as the elements of the lock that co-operate with the parts of the key that form the subject of the present invention.

[0013] In the example illustrated in the drawings, the lock 4 is of the type comprising a body including a pair of stators 41, 42, rotatably mounted within which are respective rotors 50, designed to be driven on the opposite sides of a door on which the lock is mounted. Of course, the above example does not have any limiting value since the key of the invention could be used with any type of cylinder lock, with single or double cylinder. In a way in itself conventional, in the case of the example illustrated, the body 4 includes an intermediate bridge portion 43 provided with a threaded hole 44 for engagement of a screw (not illustrated) designed to fix the body of the lock within the structure of the door. The drawings do not show the pawl (or cogwheel cam) for governing the lock of the door that is fixed in rotation with respect to the rotors 50 and is provided in the space 45 that separates the two rotors 41, 42 axially from one another.

[0014] With reference in particular to Figure 3, each rotor 50 has a passage 51 for introduction of the key 1. Facing the passage 51 is a pin 60 designed to co-operate with the key, which is slidably mounted in a hole 61 of the rotor 50 and cooperates with a counterpin 62 slidably mounted in a hole 63 of the body 42 of the stator. The hole 63 is closed at its bottom end by a plug 64 and contains inside it a helical spring 65 that is set between the plug 64 and the counterpin 62 so as to push the pin 60, via the counterpin 62 (in the neutral position of the rotor 50 that is represented in the drawings) towards an end-of-travel position, in which a head 60a of the pin 60 comes to bear upon a shoulder defined by an end portion of widened diameter of the hole 61.

[0015] With reference now in particular to Figures 4, 7, and 10, the key according to the invention comprises a first engagement member 301 and a second engagement member 302, each of which is designed to co-operate with the pin 60 carried by the rotor 50, according to the direction of introduction of the key. The two engagement members 301, 302 are pushed towards a position where they project from the two main faces 31, 32 by spring means, which in the example illustrated are constituted by a helical spring 303. The helical spring 303 pushes the two engagement members 301, 302 by means of a third control member 304.

[0016] With reference to Figure 4, the spring 303 pushes the control member 304 towards a position in which the control member 304 sets itself between the first and second engagement members 301, 302, in such a way as to maintain the latter in positions where they project.

[0017] The control member 304 is movable in the longitudinal direction of the body 3 of the key within an axial cavity 305 obtained starting from the end surface 35 of the key. The helical spring 303 is set between the bottom of the axial cavity 305 and the third control member 304 so as to push the control member 304 in the longitudinal direction, towards the end 35 of the key, so as to wedge between the two engagement members 301, 302 and push them into positions where they project.

[0018] The two engagement members 301, 302 are movable within two holes 306, 307 obtained in the main faces 31, 32 of the body of the key, orthogonal to said main faces and giving out onto the aforementioned axial cavity 305.

[0019] Preferably, the two holes 306, 307 are obtained by means of a single operation of perforation with a bit with tapered tip, which bestows a corresponding conical conformation on the rim of the hole 307 that gives out onto the main face 32. In this way, the above conical rim constitutes a surface for arresting movement of the engagement member 302 towards its position where it projects from the main face 32. On the other side of the key, the rim of the hole 306 facing the main face 31 is deformed permanently (thanks to the malleability of the metal material constituting the body of the key) so as to obtain also on the aforesaid side a contrast surface for the movement of the engagement member 301 towards its projecting position.

[0020] Figures 2-4 show the lock 4 and the key 1 in the condition in which they are before the key is introduced into the lock. On the key, the engagement members 301, 302 occupy the position in which they project from the main faces 31, 32, as a result of the thrust exerted by the helical spring 303 via the control member 304. In the lock, the pin 60 is held by the spring 65, via the counterpin 62, in its end-of-travel position (Figure 3) in which the counterpin 62 extends partially within the mouth with widened diameter of the hole 61 so as to prevent any rotation of the rotor 50. Of course, in this condition, rotation of the rotor 50 is prevented also by all the further control elements with which the lock is provided and which, as has been mentioned above, are not described and illustrated in detail herein.

[0021] During introduction of the key into the lock (Figures 5-7), the opposite walls of the cavity 51 force the engagement members 301, 302 to recede within the respective openings 306, 307 into the cavity 305, causing the control member 304 to recede towards the bottom of the cavity 305 accordingly, compressing the helical spring 303 (Figure 7). As may be seen, in the case of the embodiment illustrated herein, the above condition brings the two engagement members 301, 302 to come into contact with one another, even though this condition is not in principle essential.

[0022] When the key reaches the position where it is completely introduced into the cavity 51 of the lock, one of the two engagement members 301, 302 comes into contact with the radially internal end of the pin 60 and can push it into the position illustrated in Figure 9, as a result of the thrust exerted by the spring 303 via the control member 304. In said condition, the action of the spring 303 overcomes that of the spring 65. At the same time the other engagement member can also move into its projecting position, in so far as it comes to occupy a position corresponding to a transverse groove 500 obtained in the wall of the cavity 51 that faces the one in which the hole 61 is formed. The above condition is clearly visible in Figures 9 and 10. In this condition, rotation of the rotor 50 is enabled in so far as the co-operating surfaces of the pin 60 and counterpin 62 are exactly on the outer circumferential profile of the cross section of the rotor 50. In this condition, the further cavities and/or grooves provided on the key co-operate with the further control elements of the lock (not illustrated) to enable rotation of the rotor, according to any known solution.

[0023] When the key is again extracted, the pin 60 and the counterpin 62 return into the resting position illustrated in Figure 3, whilst the engagement members 301, 302 and the control member 304 return temporarily into the retracted positions visible in Figure 7 until the key is completely extracted from the lock. With the key in the extracted condition, the engagement members 301, 302 and the control member 304 return into the projecting positions illustrated in Figures 4 and 10.

[0024] As may be seen, thanks to the aforesaid characteristics, the key of the invention guarantees a more efficient and reliable operation as compared to known solutions. The two engagement members are independent of one another, but notwithstanding this are forced by the control member to present always a symmetrical movement, which prevents any of said members from displacing between the retracted position and the projecting position, unless the other member can perform a corresponding movement.

[0025] As already mentioned, the invention is also aimed at a key blank having the characteristics described above. Basically, an example of embodiment of the key blank can be understood as the key illustrated in Figure 1, with the cavity 305 and the holes 306, 307, the two engagement members 301, 302, the control member 304, and the spring 303, but without all the surfaces, grooves, and cavities that transform the blank into a key suited to operating on a given lock.

[0026] Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described and illustrated purely by way of example, without thereby departing from the scope of the present invention.

[0027] For example, the engagement members 301, 302 and/or the control member 304 could have a conformation different from the spherical conformation illustrated above. For instance, the engagement members 301, 302 could have a cylindrical conformation with spherical ends, and the same applies to the control member 304. Once again alternatively, the members 301, 302 could have a prismatic conformation and be guided in the respective holes 306, 307 so that they cannot turn about respective axes. Likewise, the control member 304 could have any conformation, with a wedge-shaped end co-operating with inclined plane surfaces of the engagement members 301, 302.

[0028] Also in the case of spherical conformation of the members 301, 302, 303, the member 304 could be constituted by a ball of a diameter different from that of the balls 301, 302, unlike the example illustrated, in which the three balls 301, 302, 304 have an identical diameter. Inside the axial cavity 305 of the key there may be provided a closing plug.

[0029] Moreover, the cavity 305 might not give out onto the end surface of the key and may be obtained, instead, starting from a side of the key. According to a further variant, the spring 303 is not set between the member 304 and the bottom of the cavity 305, but rather is located on the opposite side of the member 304, for example between the latter and a plug inserted into the end of the cavity 305, in the case where the cavity gives out onto the end 35 of the key. In the case where the cavity 305 is obtained starting from a side of the key, the spring 303 could be set indifferently on one side or on the other of the member 304, between the latter and a corresponding end of the cavity.

[0030] As emerges clearly from the foregoing description, the key according to the invention is characterized in that the spring means 303 push the engagement members 301, 302 via the third control member 304 that moves along the longitudinal axis of the key.

[0031] As already mentioned, the invention must be considered both with reference to a key already formed with its surfaces, cavities, and/or grooves for co-operating with the control elements of a specific lock, and with reference to a simple key blank, which is in any case provided with the essential elements of the invention that have been described above.

Claims

1. A key or key blank for a cylinder lock, comprising:

- a head (2);

- a substantially elongated and flattened body (3), connected to the head (2) and having two opposite main faces (31, 32), at least one of which is configured for co-operating with elements of the cylinder lock; and

- a first engagement member (301) and a second engagement member (302), which are provided for co-operating with elements of the cylinder lock and are movable, within holes (306, 307) formed through said body (3) and giving out onto said main faces (31, 32), each between a position where it projects from a respective main face and a position where it is retracted within the respective hole; and

- spring means (303) provided within said body (3), which push said first and second engagement members (301, 302) towards positions where they project from said main faces (31, 32),
said key or key blank being characterized in that said spring means (303) push said first and second engagement members (301, 302) via a third control member (304), which is movable within said body (3) in a longitudinal direction of said body and is pushed by said spring means (303) towards a position in which it sets itself between said first and second engagement members (301, 302) in such a way as to keep them in positions where they project.

2. The key or key blank according to Claim 1, characterized in that said control member (304) is mounted within an axial cavity (305) of said body (3) formed starting from an end surface (35) of said body opposite to said head (2).

3. The key or key blank according to Claim 2, characterized in that said spring means (303) are constituted by a helical spring provided within said axial cavity (305), between the bottom of said cavity and said control member (304).

4. The key or key blank according to Claim 1 or Claim 2 or Claim 3, characterized in that said first and second engagement members (301, 302) and said control member (304) are balls.

5. The key or key blank according to Claim 4, characterized in that said first and second engagement members (301, 302) and said control member (304) are balls of identical diameter.

6. The key or key blank according to any one of the preceding claims, characterized in that said body (3) is provided for defining arrest surfaces for said first and second engagement members (301, 302) towards positions where they project.

7. The key or key blank according to Claim 6, characterized in that said body (3) is made of metal material, in that one (307) of said holes gives out onto one (32) of said main faces with a conical end portion, which defines the arrest surface for one (302) of said engagement members, and in that the rim of the other hole (306) is permanently deformed for defining the arrest surface of the other engagement member (301).

8. The key or key blank according to Claim 1 or Claim 2 or Claim 3, characterized in that said first and second engagement members each have a cylindrical conformation with spherical ends.

9. The key or key blank according to Claim 8, characterized in that said control member (304) has a cylindrical conformation with at least one spherical end in contact with said engagement members (301, 302).

10. The key or key blank according to Claim 1 or Claim 2 or Claim 3, characterized in that said first and second engagement members (301, 302) have a prismatic conformation, and in that said control member (304) has a wedge-shaped end in contact with said first and second engagement members (301, 302).

Drawing