WO1996020324A1

WO1996020324A1 - Key and cylinder lock unit

Info

Publication number: WO1996020324A1
Application number: PCT/EP1995/004864
Authority: WO
Inventors: Renato Botteon
Original assignee: Silca S.P.A.
Priority date: 1994-12-27
Filing date: 1995-12-11
Publication date: 1996-07-04
Also published as: IT1268686B1; AU4260896A; ITVE940053A0; ITVE940053A1

Abstract

A key and cylinder lock unit, in which the lock (2) comprises a plug (6) and a cylinder (8), both provided with a plurality of substantially radial cylindrical recesses (12, 10) housing pins (16, 18) formed in two parts separated by a surface, which when they assume a predetermined axial and rotational position enable the plug (6) to rotate relative to the cylinder (8) under the control of a key inserted into a corresponding longitudinal seat (14) provided in the plug (6) and interacting with the end of said pins which extend into said seat, characterised in that: the lateral surface of the plug (6) and/or of the cylinder (8) is defined by the rotation of a non-rectilinear generating line about the plug axis; the surface of discontinuity between the two constituent parts of each pin (16, 18) being shaped such that when the pin (16, 18) assumes within the respective recess that axial and rotational position corresponding to plug release, said surface of discontinuity presents a profile analogous to the surface generated by the rotation of said generating line.

Description

KEY AND CYLINDER LOCK UNIT

This invention relates to a key and cylinder lock unit. Locks are known comprising a cylinder forming the lock body and a plug housed in the cylinder and provided with a radially projecting pawl for operating a bolt.

The cylinder and plug comprise a plurality of radial cylindrical recesses in which pins formed in two parts are housed and can slide axially. When the key is absent the axial position of the pins is such that the separation surface between their two constituent parts does not coincide with the surface of discontinuity between the plug and cylinder, with the result that the pins act as locking members for preventing the plug rotating relative to the cylinder. When however the key is inserted into a corresponding longitudinal seat provided in the plug, it causes the various pins to move axially in accordance with its pattern, such as to make the separation surface between the two constituent parts of each pin coincide with the surface of discontinuity between the plug and cylinder, to enable the plug to be rotated by said key.

Locks are also known in which the plug is released from the cylinder not only for a particular axial position of each pin but also for a particular rotational position of each pin. In this respect, that part of each pin housed in th plug comprises a longitudinal cavity, which for a particula angular position results in the yielding within the plug o side bar which normally engages a corresponding longitudina cavity provided in the cylinder.

This known type of lock is considerably mor advantageous because of the greater level of security it ca offer, given the larger number of conditions which the ke pattern must satisfy to unambiguously define the axia position and rotational position of each pin, and because o the extreme difficulty encountered in tampering to identif the correct angular position of each pin and to move it i this position.

However it involves a more complicated constructio because of the presence of the side bar, which represents member additional to the pins and results in inevitabl machining tolerances which can be utilized in tampering.

An object of the invention is to provide a key an cylinder lock unit in which the plug is released from th cylinder for a particular axial and rotational position o each pin, but for which no member additional to the pins i required.

A further object of the invention is to provide a ke and cylinder lock unit in which the difficulty of reproducing the key by unauthorized persons and the difficulty of operating the lock without a key expressly cut for the particular lock are further increased, with a consequently increased level of security and reliability of the lock.

These and further objects are attained according to the invention through a key and cylinder lock unit as described in claim 1.

Two embodiments of the present invention are described in detail hereinafter with reference to the accompanying drawings, in which: Figure 1 is a partly sectional perspective view of a key and lock unit according to the invention; Figure 2 is a longitudinal section on the line II-II of Figure 3 showing the lock in the locked state without its key; Figure 3 is a longitudinal section on the line III-III of

Figure 2; Figure 4 is a cross-section on the line IV-IV of Figure 2; Figure 5 is a longitudinal section on the line V-V of Figure

6 showing the lock in the released state with the key inserted; Figure 6 is a longitudinal section on the line VI-VI of Figure 5; Figure 7 is a cross-section on the line VII-VII of Figure 5; Figure 8 is a perspective view of the key of the unit of

Figure 1; Figure 9 is an exploded perspective view showing the two constituent parts of each lock pin; Figure 10 shows a different embodiment of the lock of a unit according to the invention in the same view and the same state as Figure 2; Figure 11 is a longitudinal section on the line XI-XI of

Figure 10; Figure 12 is a cross-section on the line XII-XII of Figure

10; Figure 13 shows it in the same view as Figure 10, but in the released state with the key inserted; Figure 14 is a longitudinal section on the line XIV-XIV of

Figure 13; Figure 15 is a cross-section on the line XV-XV of Figure 13; Figure 16 is a a view of the key shank taken on the pattern side. As can be seen from Figures 1-9, the unit according to the invention comprises a cylinder lock, indicated overall by 2, and a key, indicated overall by 4. The lock comprises a plug 6 housed in a cylindrical cavity of a cylinder, of the type for example commonly known as a "European cylinder", ie with a cylindrical portion housing the plug 6 and a radial appendix housing the pin mechanism for locking and releasing the plug.

Specifically, the cylinder 8 comprises a plurality of cylindrical recesses 10 (five in the illustrated example) having their axes mutually parallel and perpendicular to the axis of the cylindrical cavity housing the plug 6, which also comprises a like nu er of cylindrical recesses 12 of the same diameter, these being coaxially aligned with the corresponding recesses in the cylinder 8 when the plug 6 is in a certain precise angular position.

The five recesses 12 of the plug 6 open into a longitudinal seat 14, also provided in the plug 6, for the insertion of the key 4.

The lateral surface of the plug 6 is defined by a generating line which in the illustrated example is a castellation but could be of a different stepped or non- rectilinear pattern, which by rotating about the axis of the plug results in an alternation of circumferential grooves and ribs.

Pairs of pins 16 and counterpins 18 are free to slide axially in and rotate within each pair of aligned recesse 10,12 of the cylinder 8 and plug 6 respectively, and are i mutual contact along a stepped surface (see Figure 9) whic for a particular axial and rotational position of each pin counterpin pair exactly prolongs the lateral surface of th plug 6. Each counterpin 18 is associated with a spring 2 also housed in the corresponding cylindrical recess 10 an interposed between said counterpin 18 and a cap 24 applicabl to the end of the same recess 10. The purpose of the sprin 22 is to urge the pin-counterpin pair towards th longitudinal seat 14 until a retention appendix 26 emergin radially from the pin 16 encounters a shoulder 28 of longitudinal channel 29 provided in the body of the plu between the adjacent pins 16, its purpose being to limit th rotation of the pin-counterpin pair between the two walls o said channel 29. That end of each pin 16 distant from th counterpin 18 is provided with an eccentric appendix 30, th dimensions of the various parts concerned being such tha when each retention appendix 26 rests against th corresponding shoulder 28, the eccentric appendix 30 of eac pin 16 projects into the longitudinal seat 14 for the key 4.

The key 4 comprises a handgrip 33 and a shank 34 o overall parallelepiped section, with a chamfered tip and wit each major face comprising a continuous channel 36 of width just greater than the diameter of the eccentric appendices 30. For the operation of the key it would be sufficient for the channel 36 to be provided on only one face of the key, however the presence of two channels symmetrical about the longitudinal axis of the key makes this reversible.

The channel 36, which is open and is slightly diverging at the end of the key 4, is formed from a succession of several rectilinear portions arranged at an angle to each other so as to cause the channel to assume a broken-line configuration. In addition, the depth of the various portions is not constant and consequently the junction points of adjacent portions are at different distances from the outer face of the key. The operation of the key and lock unit according to the invention is as follows: with the key extracted, for the reasons which will be more apparent hereinafter, all the pin-counterpin pairs are positioned such that the radial appendices 26 provided on the pins 16 adhere to the corresponding shoulders 28 and the eccentric appendices 30 have the same angular position in the recess 12 housing the corresponding pin 16. In this position the stepped surface of discontinuity between each pin 16 and the relative counterpin 18 is such as not to allow the plug to be rotated relative to the cylinder 8.

If a key 4 provided with the correct channel 36 f operating that lock is now inserted into the seat 14 of t plug 6, this insertion causes the channel 36 to engage t appendices 30 successively encountered and, because of t shape of said channel 36, to rotate and axially move t corresponding pin-counterpin pair within the respecti cylindrical seat 10,12. When the key has been completely inserted into its se (see Figure 5) , the arrangement of each pin-counterpin pa is such that the separation surface between the two exact prolongs the stepped lateral surface of the plug 6, to hen enable this latter to be rotated by the key 4. After the lock has been operated, extraction of the k 4 causes the various pin-counterpin pairs to move in t reverse direction, and when the key has been complete extracted all the pair lie at the same angle corresponding the position of the open end of the channel 36. This position is totally different from that set by t key 4 when completely inserted, and maintains the plug locked to the cylinder 8.

In the embodiment shown in Figures 10-16, that end each pin 16 which opens into the longitudinal seat 14 is wedge shaped, the patten of the key 4 correspondingly consisting of a plurality of triangular notches of different depth formed in the edge of the key. The opening of each notch is equal to the opening of the wedge-shaped end of each pin 16, whereas the vertex edge of each notch is inclined, its inclination determining the angular position of the corresponding counterpin-pin pair, by which the lateral surface of the plug 6 is prolongated by the pin-counterpin discontinuity surfaces.

Again in this case inserting the key 4 into the seat 14 of the lock 2 causes each pin-counterpin pair to move axially and rotate, until their surface of discontinuity prolongs the surface of the plug 6 to enable this to be rotated by the said key 4.

Independently of the embodiment used, it is apparent that for the plug to be released from the cylinder, the unit of the invention requires each pin to assume a precise axial and rotational position, this being achieved without the presence of any member additional to the pins. It therefore offers a considerable guarantee of security and reliability although being of simpler construction, thus making it extremely difficult to duplicate the key while at the same time making it practically impossible to operated the lock without its own key.

Claims

C A I M S 1. A key and cylinder lock unit, in which the lock (2) comprises a plug (6) and a cylinder (8) , both provided with a plurality of substantially radial cylindrical recesses (12,10) housing pins (16,18) formed in two parts separated by a surface, which when they assume a predetermined axial and rotational position enable the plug (6) to rotate relative to the cylinder (8) under the control of a key inserted into a corresponding longitudinal seat (14) provided in the plug (6) and interacting with the end of said pins which extend into said seat, characterised in that:

- the lateral surface of the plug (6) and/or of the cylinder (8) is defined by the rotation of a non-rectilinear generating line about the plug axis,

- the surface of discontinuity between the two constituent parts of each pin (16,18) being shaped such that when the pin (16,18) assumes within the respective recess that axial and rotational position corresponding to plug release, said surface of discontinuity presents a profile analogous to the surface generated by the rotation of said generating line.

2. A unit as claimed in claim 1, characterised in that each pin comprises a first part (16) or actual pin, house completely within the corresponding cylindrical recess (12) provided in the plug (6) , and a second part (18) o counterpin, which is housed within the correspondin cylindrical recess (10) provided in the cylinder (8) and o which part becomes housed within the relative cylindrica recess (12) of the plug (6) when the lock is locked.

3. A unit as claimed in claim 2, characterised in that th lateral surface of the plug (6) and/or of the cylinder (8) comprises an alternation of ribs and grooves, the surface o discontinuity between each pin (16) and the relativ counterpin (18) correspondingly comprising at least one step.

4. A unit as claimed in claim 2, characterised in that that end of each pin (16) opening into the seat (14) for the key (4) is provided with an eccentric appendix (30), the key (4) comprising in that face facing said pins (16,18) a continuous channel (36) open towards the end of the key and of a suitable width for housing the appendices (30) of all the pins, it extending longitudinally with different depths and with a non-rectilinear path.

5. A unit as claimed in claim 4, characterised in that the open end of the channel (36) is flared.

6. A unit as claimed in claim 4, characterised in that in the two opposing surfaces of its shank (34) , the key (4) comprises two channels (36) symmetrical about the longitudinal axis of said shank.

7. A unit as claimed in claim 2, characterised in that with each pin (16) there is associated a radial appendix (26) delimiting the axial and rotational movement of said pin (16) and of the counterpin (18) associated with it.

8. A unit as claimed in claim 7, characterised in that the plug (6) comprises a longitudinal channel (29) traversing all the cylindrical recesses (12) and delimiting between adjacent recesses a space for the movement of said radial appendices (26) .

9. A unit as claimed in claim 2 , characterised in that that end of each pin (16) opening into the seat (14) for the key (4) is wedge-shaped, the key comprising along at least one edge a plurality of notches which are complementary to said wedge, are of different depths, and have their vertex edges differently inclined one to another.