WO2007077202A1

WO2007077202A1 - Break-in resistant cylinder for locks

Info

Publication number: WO2007077202A1
Application number: PCT/EP2006/070275
Authority: WO
Inventors: Luciano Darchini; Fausto Fustini; Stefano Servadei
Original assignee: Cisa S.P.A.
Priority date: 2006-01-04
Filing date: 2006-12-29
Publication date: 2007-07-12
Also published as: ITBO20060008A1

Abstract

A break-in resistant cylinder (1) for locks, comprising a stator (2) provided with a substantially cylindrical longitudinal cavity (3) for accommodating a rotor (4) with a longitudinal recess (5) for the insertion of a key (6). The rotor (4) and the stator (2) comprise a plurality of channels (7) which are substantially aligned and face each other when the cylinder (1) is in the closed configuration, channels (7) for accommodating respective coding pins (8), tumbler pins (9) and any elastic means (7a) designed to prevent the rotation of the rotor (4) within the stator (2) if the key (6) is not present in the longitudinal recess (5). At least one portion of at least one channel (7) of the stator (2) comprises at least one lateral compartment (10) for accommodating a movable unit (11) which interferes, in the inactive configuration, with the channel (7). At least the tumbler pin (9) associated with the channel (7) provided with a compartment (10) has a central region with reduced diameter (12) which is interposed between two end heads (13) whose diameter approximates, but is smaller than, the diameter of the channel (7).

Description

BREAK-IN RESISTANT CYLINDER FOR LOCKS

Technical Field

The present invention relates to a break-in resistant cylinder for locks, particularly suitable to thwart break-in actions which comprise impulsive percussions on at least one portion of the cylinder.

Background Art

Locks currently exist which comprise a cylinder (in which the opening key is to be inserted) provided with a stator and a rotor which are mutually coupled by means of a plurality of coding pins and tumbler pins which can slide within stator and rotor channels: each stator channel faces, and is aligned with, the respective rotor channel when the cylinder is in the closed configuration (the key is not inserted or is inserted but not rotated with respect to the insertion configuration).

An axially-acting elastic element is provided between the bottom of the stator channel and the lower surface of the tumbler pin and is designed to keep the tumbler pin spaced from said bottom, barring external actions which entail the lowering of the tumbler pin (for example the insertion of the key in the cylinder).

The key, thanks to its contoured (coded) profile, acts on the upper surface of the coding pins, lowering them and placing the shear line which separates the bottom of the coding pin from the apex of the tumbler pin in perfect alignment with the shear line that is present between the rotor and the stator, which are substantially mutually disengaged (when the key is inserted). The rotor (when the key is inserted, therefore with the coding pins lowered according to the coding) can be turned by turning the head of the key, which protrudes from the cylinder: in this manner it is possible to open the lock.

Highly effective break-in techniques have been devised recently which are based on the possibility that the effractor may acquire uncoded keys of the same type as the one associated with a given cylinder.

A key of this type has to be shaped by providing a succession of grooves whose depth is equal to, or greater than, the maximum depth that is present in the original key (associated with the cylinder of interest) and possibly by removing a small part of material from the portion of the key that abuts against the front of the cylinder.

Once this "generic" key has been provided, the break-in action consists in inserting the key in the cylinder, subjecting it to torque and rhythmically striking its protruding head with a means of substantial mass. The percussion of the mass on the head of the key entails a small and very fast advancement of the key in the cylinder, with a consequent impulsive impact of the inclined surface of each of the grooves against the head of the respective coding pin of the cylinder: as a consequence of this impact, the coding pin transfers the accumulated energy to the tumbler pin (since they rest against each other), which is propelled toward the bottom of the stator channel, compressing the spring or other elastic means.

If, following a certain number of successive percussions, all the tumbler pins are at the same time each completely within the respective stator channel, at that instant the rotor and the stator are mutually disengaged (the rotor can rotate freely): the torque applied to the head of the key at that moment entails a rotation of the rotor and therefore the opening of the lock.

The described break-in action is substantially applicable to all types of cylinder and is therefore extremely dangerous also in view of the fact that often it does not even leave marks which might indicate that tampering has occurred.

Disclosure of the Invention

The aim of the present invention is to obviate the above-mentioned drawbacks and meet the mentioned requirements, by providing a break-in resistant cylinder for locks which cannot be opened with the described break-in method.

Within this aim, an object of the present invention is to provide a cylinder which is simple, relatively easy to provide in practice, safe in use, effective in operation, and has a relatively low cost. This aim and this and other objects that will become better apparent hereinafter are achieved by the present break-in resistant cylinder for locks, of the type which comprises a stator provided with a substantially cylindrical longitudinal cavity for accommodating a rotor with a longitudinal recess for the insertion of a key, said rotor and said stator comprising a plurality of channels which are substantially aligned and face each other when the cylinder is in the closed configuration, channels for accommodating respective coding pins, tumbler pins and any elastic means designed to prevent the rotation of the rotor within the stator if the key is not present in said longitudinal recess, characterized in that at least one portion of at least one channel of said stator comprises at least one lateral compartment for accommodating a movable unit which interferes, in the inactive configuration, with said channel, and in that at least the tumbler pin associated with said channel provided with a compartment has a central region with reduced diameter which is interposed between two end heads whose diameter approximates, but is smaller than, the diameter of said channel. Brief Description of the Drawings

Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of a break-in resistant cylinder for locks, illustrated by way of non-limiting example in the accompanying drawings, wherein:

Figure 1 is a sectional front view, taken along a transverse vertical plane, of an embodiment of a cylinder according to the invention in the inactive configuration; Figure 2 is a sectional front view, taken along a transverse vertical plane, of an embodiment of a cylinder according to the invention with the key, modified for break-in purposes, inserted;

Figure 3 is a sectional front view, taken along a transverse vertical plane, of an embodiment of a cylinder according to the invention with the key, modified for break-in purposes, inserted in a position which is partially rotated as a consequence of percussions applied to said key;

Figure 4 is an enlarged- scale sectional side view, taken along a longitudinal vertical plane, of details of an embodiment of a cylinder according to the invention; Figure 5 is a side view of a tumbler pin of an embodiment of a cylinder according to the invention;

Figure 6 is a sectional side view, taken along a vertical plane, of a lateral compartment of an embodiment of a cylinder according to the invention. Ways of carrying out the Invention

With reference to the figures, the reference numeral 1 generally designates a break-in resistant cylinder for locks.

The cylinder 1 comprises a stator 2 which is provided with a substantially cylindrical longitudinal cavity 3 for accommodating a rotor 4 with a longitudinal recess 5 for the insertion of a key 6: the key 6 is the one designed to open the cylinder 1.

The rotor 4 and the stator 2 comprise a plurality of channels 7: the portion of channel 7 comprised within the stator 2 and the portion comprised within the rotor 4 are substantially aligned and face each other when the cylinder 1 is in the closed configuration.

The channels 7 are designed to accommodate respective coding pins

8, tumbler pins 9 and any elastic means 7a intended to prevent the rotation of the rotor 4 within the stator 2 if the key 6 is not present in the longitudinal recess 5. At least one portion of at least one channel 7 of the stator 2 comprises a lateral compartment 10 for accommodating a movable unit 1 1 which interferes, in the inactive condition, with the channel 7. In practice, the lateral compartment 10 is designed to movably accommodate the unit 11, which can indeed perform a translational motion at right angles to the longitudinal direction of the channel 7: the purpose is to make the end of the unit 11 protrude into the channel 7; such end interferes with the vertical translational motion of the tumbler pin 9 and in particular brakes it when it undergoes sudden accelerations, since friction is considerable in such situations (the two surfaces are instantaneously pressed into mutual contact with great force).

At least the tumbler pin 9 associated with the channel 7 provided with the compartment 10 has a central region 12 with a reduced diameter, which is interposed between two end heads 13 whose diameter approximates, but is smaller than, the diameter of the channel 7. In this manner, the end surface of the unit 1 1 is in contact with the surface of the region 12, when the tumbler pin 9 performs a translational motion within the channel 7; descending, the end of the unit 11 strikes the step that separates the region 12 from one of the heads 13 : if the impact is instantaneous, the step tends to jam on the surface of the unit 11 and the tumbler pin 9 is stopped suddenly. The compartment 10 has a large external portion 14 and a smaller inner portion 15; the portions 14 and 15 are separated by a step 16.

The movable unit 11 instead comprises a substantially circular end region 17, which is surmounted by a dome 18: the end region 17 has a larger diameter than the dome 18 and constitutes an actual shoulder. The end region 17 has a receptacle 19 on the surface that lies opposite the surface of the dome 18: the receptacle 19 constitutes the seat which accommodates an elastic element (described hereinafter) designed to keep the unit 11 in the configuration in which it protrudes into the channel 7.

The dome 18 has a maximum diameter which is substantially smaller than the diameter of the inner portion 15 of the compartment 10; the end region 17 has a diameter which is comprised between the diameter of the inner portion 15 and the diameter of the outer portion 14: in this manner, the dome 18 can protrude into the channel 7 only by a certain length, since the edge of the end region 17 then abuts against the step 16, blocking the stroke of the unit l l.

The compartment 10 further comprises a closure plate 20, which constitutes the end plug for the compartment 10 once the unit 11 has been inserted.

An axially-acting elastic means 21 (already mentioned earlier) is comprised and interposed between the closure plate 20 and the unit 11, and is designed to keep the unit 11 so that the end of the dome 18 protrudes into the portion of the cavity 7 of the stator 2, in a configuration for interfering with the stroke of the tumbler pin 9.

According to the embodiment shown in the figure, the elastic means 21 is a helical spring with a conical profile, whose vertex 22 is adapted to be inserted within the recess 19.

It should be noted that in a practical embodiment the heads 13 can also have mutually different heights: in particular, the head 13 in contact with the coding pin 8 is higher so as to be arranged in the channel 7, at the shear line between the stator 2 and the rotor 4, when the end of the dome 18 rests on its lower rim. Opening of the cylinder 1 by picking is therefore prevented in this configuration.

The principle on which the operation of such a cylinder 1 is based is the principle of so-called "Newton's cradle": a plurality of steel balls hang from an upper frame in substantial mutual alignment. The movement of one of the end balls entails its impact, during oscillation, against the surface of the adjacent ball. The balls that lie next to the adjacent ball remain stationary, while the last ball of the row is propelled outward so as to oscillate. At this point, motion continues in a substantially symmetrical and damped manner. The percussion of the key 6 on the coding pin 8, which rests against the head 13 of the tumbler pin 9, entails the transfer of energy (and therefore of motion) to the tumbler pin 9, which is propelled downward, while the other components remain stationary. The unit 11 is indeed designed to brake the impulsive strokes of the tumbler pin 9 by trapping it, while allowing it to move easily in case of non-impulsive motion (at a lower speed, for example when using a key for normal opening).

It has thus been shown that the invention achieves the intended aim and object. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

All the details may further be replaced with other technically equivalent ones. In the exemplary embodiments shown, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

In particular, it is possible to provide any number of compartments 10 at will, each matched by a respective unit 11 and distributed along the portion of the channel 7 of the stator 2, according to the constructive requirements.

Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer. In practice, the materials used, as well as the shapes and dimensions, may be any according to requirements without thereby abandoning the scope of the protection of the appended claims.

The disclosures in Italian Patent Application No. BO2006A000008 from which this application claims priority are incorporated herein by reference.

Claims

1. A break- in resistant cylinder for locks, of the type which comprises a stator (2) provided with a substantially cylindrical longitudinal cavity (3) for accommodating a rotor (4) with a longitudinal recess (5) for the insertion of a key (6), said rotor (4) and said stator (2) comprising a plurality of channels (7) which are substantially aligned and face each other when the cylinder (1) is in the closed configuration, channels (7) for accommodating respective coding pins (8), tumbler pins (9) and any elastic means (7a) designed to prevent the rotation of the rotor (4) within the stator (2) if the key (6) is not present in said longitudinal recess (5), characterized in that at least one portion of at least one channel (7) of said stator (2) comprises at least one lateral compartment (10) for accommodating a movable unit (1 1) which interferes, in the inactive configuration, with said channel (7), and in that at least the tumbler pin (9) associated with said channel (7) provided with a compartment (10) has a central region with reduced diameter (12) which is interposed between two end heads (13) whose diameter approximates, but is smaller than, the diameter of said channel (7).

2. The cylinder according to claim 1, characterized in that said compartment (10) has a large outer portion (14) and a smaller inner portion (15), said portions (14, 15) being separated by a step (16).

3. The cylinder according to claim 1, characterized in that said movable unit (11) comprises a substantially circular end region (17) surmounted by a dome (18), said end region (17) having a larger diameter than said dome (18).

4. The cylinder according to claim 3, characterized in that said end region (17) has a receptacle (19) on the surface that lies opposite the surface of the dome (18).

5. The cylinder according to one or more of the preceding claims, characterized in that said dome (18) has a maximum diameter which is substantially smaller than the diameter of the inner portion (15) of said compartment (10) and in that said end region (17) has a diameter comprised between the diameter of the inner portion (15) and the diameter of said outer portion (14).

6. The cylinder according to one or more of the preceding claims, characterized in that said compartment (10) comprises a closure plate (20), which constitutes the end plug for said compartment (10) once said unit (11) is inserted.

7. The cylinder according to claim 6, characterized in that an axially- acting elastic means (21) is comprised and interposed between said closure plate (20) and said unit (11) and is designed to keep said unit (11) so that the end of the dome (18) protrudes into the portion of cavity (7) of the stator (2).

8. The cylinder according to claim 7, characterized in that said elastic means (21) is a substantially helical spring.

9. The cylinder according to one or more of the preceding claims, characterized in that said heads (13) have optionally mutually different heights.

10. The cylinder according to one or more of the preceding claims, characterized in that said compartments (10) are several and are distributed along the surface of the portion of the channel (7) of the stator (2) and each one comprises a respective unit (11).