Cylinder lock

Abstract: A cylinder lock including a rotor (7) rotating in a cylinder case (8) and a plurality of interference members (13) adapted to prevent the rotor (7) from rotating. Each interference member comprises a key activated first element (14) adapted to allow a second element (18) to move from a locking position of the rotor (7), to a free position of rotation of the rotor (7) in the cylinder case (8). The first element (14) is operatively connected to the second element (18) by a spring (19).

Description: The present invention relates to a cylinder lock. Conventional cylinder locks comprise a cylinder, or rotor, rotating inside a drum, or cylinder case, having: respectively a plurality of spring operated pins. The pins have different length and are biased by the springs in a radial direction such that the drum pins operate as splines preventing the rotation of the cylinder with respect to the drum. When the adapted key is introduced into the keyhole, it moves the pins such that the rotor is disengaged and can rotate with respect of the drum releasing the lock. The variation of the pin length and of the key profile, as well as the variation of the key section and of the keyhole, provides for different locks and combinations. WO 83/03869 and DE 633753C disclose a cylinder lock as described in the pre-characterizing part of claim 1. Said two patents do not teach or cylinder lock as disclosed in the characterizing portion of claim 1. Flat key locks have been recently produced, wherein the pins act upon the sides of the key rather than on the edge. Of course, new locks have to be constantly developed in order to improve the mechanical resistance and to make them more difficult to open by means of false keys or other instruments. Another important aspect to be considered in designing new locks is the production cost. In fact, typically, a larger number of combination corresponds to a higher mechanical complexity and therefore to a higher production cost. Conventional locks with complex combination mechanisms are mechanically weak, bulky or extremely expensive. An aim of the present invention is to provide a cylinder lock which overcomes the above described inconveniences of the prior art locks. A further aim of the present invention is to provide a cylinder lock having the same size of conventional locks but with a higher number of combinations. An object of the invention is to provide a mechanically stronger lock. A further object of the invention is provide a cylinder lock with lower production costs with respect to locks of similar performance regarding the number of combinations. The above aims, as well as these and other objects that will be more apparent hereinafter, are achieved by a cylinder lock as claimed in claim 1. Further characteristics and advantages of the invention will be more apparent by the following description of an embodiment of the invention, illustrated, by way of example in the enclosed drawings wherein: FIG. 1 is a side section view of a cylinder lock according to the invention; FIG. 2 is a front section view of the lock in the closed position with a key having a correct combination inserted therein; FIG. 3 is a front section view of the lock during the rotation with a correct combination key; FIG. 4 is a front section view of the lock in the closed position having a key with a wrong combination inserted therein; FIG. 5 is a front section view of the lock showing a key with the wrong combination, wherein the key seat is too long, trying to turn the lock open; FIG. 6 is a front section view of the lock in the closed position having inserted therein a key with the wrong combination wherein the key lock seat is not sufficiently deep. With reference to the above figures, the cylinder lock according to the invention, generally designated by the reference numeral 1, comprises an inner portion 2 and an outer portion 3, each provided with a key hole 4 and 5 respectively, for inserting a key 6. Only the outer portion 3 will be described hereinafter for brevity, since the inner and outer portions are substantially identical. The lock comprises a rotor 7 rotating inside a cylinder case 8 and having a plurality of pins 9, of conventional type, operated by pistons 10 that are activated by springs 11 arranged in radial seats 12 in the cylinder case 8. According to the invention, the lock comprises a plurality of interference members 13 adapted to lock and to unlock the rotation of the rotor 7 with respect to the cylinder case 8. Each interference member 13 comprises a first piston element 14 axially sliding in a seat 15 formed in the rotor 7 and having a point 16 adapted to cooperate with a combination seat formed in the key 6. The first element 14 comprises a coaxial seat 17 adapted to at least partially accommodate a second piston element 18 by the interposition of at least one elastic member constituted by a spring 19. The second piston element 18 comprises a point 20 cooperating with a tapered seat 21 formed in the cylinder case 8, or in a ring 22 rigidly associated with the case 8, as in the illustrated example. The second piston element 18 also comprises a reduced portion 24 centrally located and having a smaller diameter than the mean diameter of the second element. Advantageously, the lock according to the invention also comprises a plurality of profile pins 23 free to slide in adapted seats formed in the rotor 7. In particular, profile pins 23 and the interference members 13 mutually cooperate in order that, even if the region of the key corresponding to the profile pins 23 is lowered for excluding the locking action of the profile pins, the interference members 13 will in any case prevent the rotation of the rotor with respect of the cylinder case. This solution is extremely advantageous and economic especially in applications such as hotels and similar. In the illustrated example, the lock comprises the already described conventional locking pins 9 having a per se known operation which will not be described herein, for brevity. According to the invention, when the correct key 6 is inserted in the key hole, pins 9 arrange themselves to allow the rotation of the rotor in a per se known manner. Regarding the interference members 13 instead, the point 20 of the second element 18 is inserted in the respective tapered seat 21 of the cylinder case even when the combination is correct (FIG. 2). When rotating the key (FIG. 3), the point 20 exits the tapered seat 21 because the second piston element 18 can overcome the resistance of the spring 19 allowing a small but sufficient axial motion of the second element inside the first element 14 which will instead keep still with respect of the rotor 7. FIG. 4 shows the case of a wrong key inserted in the lock. In this case the first piston element 14 is in a position too deep with respect of the rotor and the second piston element is too external with respect of the first element. When attempting to rotate the rotor 7 by means of the key 6, the second element 18 will jam inside the seat 15 (as shown in FIG. 5) at a point external to said seat 17 because instead of axially sliding it leans in the seat because of the reduced portion 24. FIG. 6 shows the case wherein the position of the first piston element 14 is too high (of course with reference to the drawings) and the spring 19, which is completely compressed, prevents any downward axial motion of the second element 18. The point 20 will not free itself from the tapered seat 21 and the second piston element will prevent the rotation of the rotor with respect of the cylinder case. The operation of the profile pistons 23 is per se known but, when acting together with the interference members 13, besides making the lock mechanically stronger by making it more difficult to insert a drill point, prevent the possibility of easily exclude the interference members. It has been seen in practice that the invention achieves the intended aims and objects by providing a lock with a sensibly higher number of combinations with respect of conventional locks having the same dimensions. The coaxial construction of the interference members is in fact very compact. The lock according to the invention is also mechanically very strong because the rotor can be maintained of large dimensions. The lock according to the invention may be provided with interference members or conventional locking members also on the key crest. Of course, the lock may comprise one or more of the elements constituted by the interference members 13, pins 9 and profile pins 23, according to various combinations. The materials employed, as well as the dimensions, may be any according to the specific needs and the state of the art.

Claims: "A cylinder lock comprising a rotor (7) rotating in a cylinder case (8) and at least one interference member (13) adapted to prevent said rotor from rotating, said interference member comprising a key activated first element (14) adapted to allow a second element (18) to move from a locking position of said rotation of said rotor, to a free position of rotation of said rotor in said cylinder case, characterized in that said first element has a point (16) cooperating with a combination seat formed in the key (6) and is hollow and comprises a seat (17) for at least said second element and is operatively connected, by means of elastic means, to said second element having a central reduced portion (24) having a diameter which is smaller than the mean diameter of said second element and a point (20) cooperating with a tapered seat (21) formed in the cylindrical case (8), wherein in said free position said second element (18) has its reduced portion (24) internal to said seat (17) and is axially movable inside said seat (17) overcoming the resistance of the elastic means in order that said point (20) exits said tapered seat (21), in said locking position said second element (18) has a first position in which it has its reduced portion (24) partially external to said seat (17) and it is jammed at a point external to said seat in order that said point (20) remains inserted in said tapered seat (21), and a second position in which said second element (18) has his reduced portion (24) internal to said seat (17) and is not axially movable in said seat (17) in order that said point (20) remains inserted in said tapered seat (21)". A cylinder lock, according to claim 1, characterized in that said first element and said second element are adapted to move in opposite directions by the interposition of said elastic means in adapted seats 15 formed in said rotor 7. The cylinder lock, according to claim 1 or 2, characterized in that said first element comprises a point (16) adapted to cooperate with a combination seat formed in said key (6). The cylinder lock, according to one or more of the preceding claims, characterized in that said second element comprises a point (20) cooperating with a tapered seat (21) formed in said cylinder case. The cylinder lock, according to one or more of the preceding claims, characterized in that said second element is formed as a piston. The cylinder lock, according to one or more of the preceding claims, characterized in that it comprises profile pins (23) free to slide in adapted seats formed in said rotor (7) and adapted to cooperate with said interference members and with respective combination seats formed in said key. The cylinder lock, according to one or more of the preceding claims, characterized in that it comprises a plurality of pins operated by respective pistons, springs arranged in radial seats in said cylinder case acting on said pistons.

Inventors: ANDREOLI PIETRO, ANDREOLI, PIETRO
Applicants: ISEO SERRATURE SPA
Application year: 1997
Main classification: E05B27
IPC codes: E05B27