Title of Invention

CYLINDER LOCK HAVING MAGNETICALLY OPERATIVE BIASSING MEANS

Abstract In a cylinder lock,one or more tumblers(11)of the rotatable cylinder(6)are subjected to magnetically biassing means(20,21). FIG 2
Full Text

"Cylinder lock having magnetically operative
biassing means"
The present invention relates to cylinder locks, of the type comprising:
a fixed lock body or stator, having a cylindrical cavity,
- a cylinder or rotor, rotatably mounted within
the cylindrical cavity of the fixed body and having an
axial passage for receiving a key,
- a plurality of locking tumblers sli.dably mounted
within radial holes of the rotatable cylinder, opening
on said axial passage, said tumblers being adapted to
be engaged at one end thereof by a key having a
predetermined profile in order to arrange themselves in
a position in which they enable a free rotation of the
rotatable cylinder within the fixed body,
a plurality of counter-tumblers, slidably mounted within holes which are formed in the fixed body of the lock and open on the cylindrical cavity of said fixed body, said holes for the counter-tumblers being adapted to become aligned with the holes for the tumblers in the rotatable cylinder at a given angular position of the latter, and
- means for biassing the tumblers radially towards the axis"_of _the rotatable cylinder when the latter is at said given angular position.
In the conventional locks of the above indicated type, the above mentioned biassing means are constituted by coil springs arranged within the holes of the fixed body wherein the counter-tumblers are movable, so as to push the counter-tumblers against the respective tumblers, towards the axis of the rotatable cylinder. These locks enable a burgler to determine the profile of the key which can open the lock, by

inserting a tool within the key hole and pushing the tips of the lock tumblers by this tool, against the action of the above mentioned coil springs.
The object of the present invention is that of proposing a new type of lock which has a higher degree of safety with respect to the conventional locks of the above indicated type.
In view of achieving this object, the invention provides a lock having all the above mentioned features and further characterized in that in the case of at least one of said tumblers the means for biassing this tumbler radially towards the axis of the rotatable cylinder are magnetically operative biassing means, which comprise a first permanent magnet arranged within the hole in the fixed body where the respective counter-tumbler is movable and a second permanent magnet associated with said key and adapted to draw the first permanent magnet towards the axis of the rotatable cylinder when the key is received within the rotatable cylinder, so that the first permanent magnet biasses the respective tumbler against the key.
Naturally, it is possible to provide one or more tumblers of the lock and, if desired, even all the tumblers of the lock, with magnetically operative biassing means.
According to a first solution, the above mentioned first permanent magnet is arranged within the respective hole of the fixed body between the respective counter-tumbler and an end wall of the hole. Alternatively, the first permanent magnet may be arranged within the respective hole of the fixed body between the respective counter-tumbler and the respective tumbler.

In order to improve the magnetic efficiency, preferably the tumbler and/or the respective counter-tumbler are made of ferromagnetic material.
The second permanent magnet is fixed within a seat formed in the key on a surface opposite to that which is for cooperating with the tumblers of the rot at able cylinder.
In case at least one of the tumblers of the rotatable cylinder has biassing means of the conventional type constituted by a coil spring arranged within the hole of the respective counter-tumbler, according to the invention the counter-tumblers associated with magnetically operative biassing means have a greater length than the counter-tumbler associated with coil spring biassing means. In this manner, a lock of conventional type can be transformed into a lock according to the invention with no modification to the geometry of the fixed body.
In case said key has a flattened active portion and accordingly the above mentioned axial passage for the key has a similar shape, having a general plane perpendicular to a plane containing the axes of the radial holes of the rotatable cylinder, the above mentioned active portion of the key has a first face having cavities adapted to cooperate with the tips of the lock tumblers and an opposite face in which the seat for each second permanent magnet is formed.
Due to the above mentioned features, when the key is not introduced into the lock, the first permanent magnet is not biassed towards the axis of the rotatable cylinder. Therefore it is impossible for a non-authorized person to introduce a tool into the key axial passage and press this tool against the tip of the above mentioned tumbler in order to determine the profile of the key which can open the lock. Thus, the

lock according to the invention has a higher degree of safety with respect to the known locks.
Accordingly the present invention provides a cylinder lock, comprising;
- a lock fixed body or stator, having a cylindrical cavity,
- a cylinder or rotor, rotatably mounted within the cylindrical cavity of the fixed body and having an axial passage for introduction of a key,
- a plurality of locking tumblers which are slidably mounted within radial holes of the rotatable cylinder which open on said axial passage said tumblers being adapted to be engaged at one end thereof by a key having a predetermined profile so as to arrange themselves to a position in which they enable a free rotation of the rotatable cylinder within the fixed body,

- a plurality of counter-tumblers slidably mounted within holes which are formed in the fixed body of the lock, and open on the cylindrical cavity of said fixed body, said holes for the counter-tumblers being adapted to become aligned with the holes of the tumblers in the rotatable cylinder at a given angular position of the latter, and
- means for biassing the tumblers radially towards the axis of the rotatable cylinder when the latter is at said given angular position,
characterized in that in the case of at least one of said tumblers, said means for biassing the tumbler radially towards the axis of the rotatable cylinder are magnetically operative biassing means which comprise a first permanent magnet arranged within the hole of the fixed body where the respective counter-tumbler is movable, and a second permanent magnet associated with said key and adapted to draw the first permanent magnet towards the axis of the rotatable cylinder when the key is received in the rotatable cylinder, so that the first permanent magnet biasses the resoective tumbler against the key.

Further features and advantages of the invention will become apparent from the description which follows with reference to the annexed drawings, given purely by way of non limiting example, in which;
- figure 1 is a perspective diagrammatic view of the lock according to the
invention, with the associated key,
- figure 2 is a cross-sectional view taken along line II-II of figure 1,
- figure 3 shows the cross-section of figure 2 in a different operative condition, and
- figure 4 shows a variant of figure 2.
In figure 1, reference numeral 1 designates a cylinder lock associated with a door frame 2 and adapted to cooperate with a key 3.
As shown in figure 2, the lock 1 is a cylinder lock, comprising a lock fixed body 4 having a cylindrical cavity 5 where a cylinder 6 is rotatably mounted.
In the case of the illustrated example, the fixed body 4 of the lock is of the type
including two body sections (only one of which is visible in the drawings) arranged
symmetrically with respect to a plane 7. The body section which is not shown in the
drawings is identical and symmetrical to that shown. However, it is clearly apparent
that the invention can be applied to any configuration of the fixed body. Also, in the
case of the illustrated example, the two body sections are connected to each other by a
bridge-like portion 8 in which a threaded hole 9 is formed for engagement of a screw
(not shown) for securing the body 4 to the lock supporting structure 2. The details of
construction are not shown herein since they can be made in any known

way and since they do not fall within the scope of the present invention. The same applies to the rotatable pawl mounted onto cylinder 6, which occupies the gap 10 between the two body sections defined by the bridgelike portion 8.
According to the conventional art, the rotatable cylinder 6 is provided with a plurality of locking tumblers 11 which are slidably mounted within radial holes 12 formed in the cylinder 6 and opening on an axial passage 13 formed in the rotatable cylinder 6 and adapted to receive the active portion 14 o.f the key. As shown in figure 1, in the case of the example described herein, the active portion 14 of the key 3 has a substantially flattened shape with a rectangular cross-section, and the passage 13 has a similar shape, with a general plane perpendicular to the plane containing the axes of the tumblers 11.
Reference numeral 15 designates a plurality of counter-tumblers which are slidably mounted, according to the conventional art, within holes 16 which are formed in the fixed body and open on the cylindrical cavity 5 of the lock. The holes 16 are adapted to become aligned with the radial holes 12 of the rotatable cylinder 6 at a given angular position of the latter.
The tips of the tumblers 11 facing towards passage 13 which is for receiving the key are for cooperation with cavities 17 formed on a first face 14a of the active portion 14 of the key 3, so that when this active portion 14 is fully received within passage 13, the tumblers 11 are each brought to an axial position which does not prevent the free rotation of the rotatable cylinder 6 within cavity 5 of the fixed body 4.

Also in the case of the illustrated example, all the tumblers 11 of the lock, except for one of them, are radially biassed towards the axis of the rotatable cylinder 6 by coil springs 18 which are interposed within the respective holes 16 between the respective counter-tumblers 15 and a closing element 19 which defines an end wall of the hole. However, according to the invention, one of the tumblers 11 is not subjected to the action of a coil spring. In this case, between the respective counter-tumbler 15 (which has a greater length than the other counter-tumblers .15) and the closure element 19 there is interposed a permanent magnet 20, in form of a circular disk, and a second magnet 21 is fixed within a seat 22 formed on the face 14b of the active portion 14 of key 3, opposite to face 14a having cavities 17, so that when the key 3 is received within passage 13, magnet 21 draws magnet 20, so that the counter-tumbler 15 and the tumbler 11 associated with magnet 20 are biassed against the key. In order to improve the magnetic efficiency, the tumbler 11 and the counter-tumbler 15 which are associated with magnet 20 are preferably constituted of ferro-magnetic material.
Figure 3 of the annexed drawings shows the condition of the lock when the key is introduced, with magnet 20 which, being drawn by magnet 21, keeps tumbler 11 associated therewith against the key. When the key is withdrawn, the tumbler 11 associated with magnet 20 is no longer biassed towards passage 13, so that it is free to fall within the respective hole 16. Therefore, if a burgler introduces a tool into passage 13, he is not able to press this tool against the above mentioned tumbler, since the latter is not biassed by any spring. For this reason, therefore, the lock

according to the invention has a higher safety degree than the known locks.
Figure 4 shows a variant in which magnet 20 is interposed between the respective tumbler 11 and the respective counter-tumbler 15.
Naturally, it is possible to replace the biassing spring 18 with the magnet 2 0 and to provide a cooperating magnet 21 on the key for more than one tumbler of the lock and, if desired, for all lock tumblers.
Furthermore, while the principle of the invention remains the same, the details of construction and the embodiments may widely vary with respect to what has been described and illustrated purely by way of example.
For example, rather than providing a magnet 21 on the key, this magnet could be provided within hole 16 adjacent to magnet 20, with polarities such as to obtain a repulsion force between the two magnets 20, 21 which would give rise to a force applied to tumbler 11. This solution could be applied both in the case of figure 3, and in the case of figure 4.


WE CLAIM:
1. A cylinder lock, comprising:
- a lock fixed body or stator (4), having a cylindrical cavity (5),
- a cylinder or rotor (6), rotatably mounted within the cylindrical cavity (5) of the fixed body (4) and having an axial passage (13) for introduction of a key (3),
- a plurality of locking tumblers (11) which are slidably mounted within radial holes (12) of the rotatable cylinder (6) which open on said axial passage (13), said tumblers being adapted to be engaged at one end thereof by a key (3) having a predetermined profile so as to arrange themselves to a position in which they enable a free rotation of the rotatable cylinder (6) within the fixed body (4),
- a plurality of counter-tumblers (15) slidably mounted within holes (16) which are formed in the fixed body (4) of the lock, and open on the cylindrical cavity (5) of said fixed body (4), said holes (16) for the counter-tumblers (15) being adapted to become aligned with the holes (12) of the tumblers (11) in the rotatable cylinder (6) at a given angular position of the latter, and
- means (18; 20, 21) for biassing the tumblers (11) radially towards the axis of the rotatable cylinder (6) when the latter is at said given angular position,
characterized in that in the case of at least one of said tumblers (11), said means for biassing the tumbler (11) radially towards the axis of the rotatable cylinder (6) are magnetically operative biassing means (20, 21) which comprise a first permanent magnet (20) arranged within the hole (16) of the fixed body (4) where the respective counter-tumbler is movable, and a second permanent magnet (21) associated with said key (3) and adapted to draw the first permanent magnet (20) towards the axis of the rotatable cylinder (6) when the key is received in the rotatable cylinder (6), so that the first permanent magnet (20) biasses the respective tumbler (11) against the key (3).

2. The lock according to claim 1, wherein the first permanent magnet (20) is arranged in the respective hole (16) of the fixed body (4) between the respective counter-tumbler (15) and an end wall (19) of 10 the hole (16).
3. The lock according to claim 1, wherein the first permanent magnet (20) is arranged in the respective hole (16) of the fixed body (4) between the respective counter-tumbler (15) and the respective tumbler (11).
4. The lock according to claim 1, wherein the second permanent magnet (21) is fitted within a seat (22) formed in the key (3) on a surface (14B) opposite of that which is for cooperating with the tumblers (11) of the rotatable cylinder (6).
5. The lock according to claim 1, in which for at least some of the tumblers (11) of the rotatable cylinder (6), the biassing means are of the conventional type constituted by a coil spring (18) arranged within the hole (16) of the respective counter-tumbler (15), wherein the counter-tumblers (15) associated with the magnetically operative biassing means have a greater length than the counter-tumblers (15) associated with coil spring biassing means (18).
6. The lock according to claim 4, wherein said key (3) has a flattened active portion (14) and said axial passage (13) has a similarly flattened shape with a general plane perpendicular to a plane containing the axes of the radial holes (12) of the rotatable cylinder (6), said active portion (14) of the key (3) having a first face (14a) with cavities (17) adapted to cooperate with the tips of the tumblers (11) of the lock, wherein each second permanent magnet (21) is fitted within a seat (22) formed on a substantially planar face (14b) of the key opposite to said first face (14a)

7. The lock according to any of the previous claims, wherein each tumbler (11) associated with a magnetically operative biassing means is made of ferro-magnetic material.
8. The lock according to any of the previous claims, wherein each counter-
tumbler (15) associated with magnetically operative biassing means is made of ferro
magnetic material.
9. A cylinder lock substantially as herein described with reference to the
accompanying drawings.


Documents:

552-mas-2000-abstract.pdf

552-mas-2000-claims duplicate.pdf

552-mas-2000-claims original.pdf

552-mas-2000-correspondance others.pdf

552-mas-2000-correspondance po.pdf

552-mas-2000-description complete duplicate.pdf

552-mas-2000-description complete original.pdf

552-mas-2000-drawings.pdf

552-mas-2000-form 1.pdf

552-mas-2000-form 19.pdf

552-mas-2000-form 26.pdf

552-mas-2000-form 3.pdf

552-mas-2000-form 5.pdf

abs-552-mas-2000.jpg


Patent Number 207294
Indian Patent Application Number 552/MAS/2000
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 04-Jun-2007
Date of Filing 18-Jul-2000
Name of Patentee M/S. MOTTURA SERRATURE DI SICUREZZA SPA
Applicant Address ANTICA DI FRANCIA 34-10057, SANT" AMBROGIO(TORINO)
Inventors:
# Inventor's Name Inventor's Address
1 SERGIO MOTTURA LANDFRANCHI 2-10131 TORINO.
PCT International Classification Number E05B47/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 99830465 1999-07-21 EUROPEAN UNION