EP1672149A1

EP1672149A1 - A motorised lock

Info

Publication number: EP1672149A1
Application number: EP04425925A
Authority: EP
Inventors: Cristian Mazzelli
Original assignee: Opera Srl
Current assignee: Opera Srl
Priority date: 2004-12-17
Filing date: 2004-12-17
Publication date: 2006-06-21

Abstract

The lock comprises: at least a bolt (2) which can be displaced between an open position of a door and the like and a closed position thereof; first means (4, 5) for activating the bolt (2), comprising a worm screw (4), having a longitudinal rotation axis (x), a nut (5) which couples with the worm screw (4) and which is associated to the bolt (2) so that a rotation of the worm screw (4) induces a displacement of the nut (5) along the longitudinal axis (x) and brings about a consequent displacement of the bolt (2); second means (7, 11, 12, 14, 15) for activating the bolt (2), comprising a mechanism predisposed to activate and thus displace the bolt (2). The nut (5) is able to vary a configuration thereof between a coupled configuration, in which the nut (5) is coupled with the worm screw (4), and a non-coupled configuration, in which the nut (5) is not coupled with the worm screw (4) and is freely slidable along the worm screw (4).

Description

The prior art contains motorised locks, mainly used for allowing or not allowing opening of doors of various kinds. These locks typically comprise a bolt, mobile between an open position and a closed position, corresponding to whether the door is open or locked.
The bolt is activated to displace between the positions of opening and closure by motorised means for activating, generally constituted by an electric gear-reducer having a worm screw for an output shaft. The worm screw is coupled to a nut which is mechanically associated to the bolt. The rotation of the worm screw induces a displacement in the nut along the longitudinal rotation axis of the worm screw, causing the bolt to move into the open or closed position.
Known-type locks are also provided with second means for activating the bolt, which for reasons of security are purely mechanical, so that the bolt can be moved into the open position should the gear-reducer be faulty. The mechanical means for activating generally comprise a mechanism constituted by a gear wheel and a rack. The rack is associated to the bolt, the gear wheel is actionable in rotation, typically by a common lock barrel: the activating of the cylinder by the key causes a rotation of the gear wheel and a translation of the rack, which in turn determines the displacement of the bolt.
As the worm screw and the nut are constantly coupled, the displacement of the bolt by means of the mechanical activating means presupposes the inversion of the mechanical chain constituted by the worm screw and the nut: the bolt and the nut become motors, while the worm screw becomes the driven organ. This is mechanically possible thanks to the step and angle properties of the thread on the worm screw, but in any case the worm screw has to be free to rotate about its own axis. In the case of faults, blockage and jamming can take place between the gears of the gear-reducer, and the electric motor itself can jam, blocking the rotor. In these cases, activating the bolt using the mechanical means is impossible as the worm screw is not free to rotate about its own longitudinal axis. This risk is totally unacceptable, for reasons of safety, and constitutes a severe limitation to the possibilities of use of motorised locks of known type.
The main aim of the present invention is to provide a motorised lock that allows a displacement of the bolt into the open position even when the worm screw is blocked, thus obviating almost entirely the risks of jamming or blocking of the bolt in the closed position.
Further characteristics and advantages of the lock of the invention will better emerge from the detailed description that follows, made with reference to the accompanying figures of the drawings, which are included by way of nonlimiting example and in which:

figure 1 is a frontal plan view of a lock according to the invention;
figure 2 is a detail of figure 1, in enlarged scale and in section, in a first operative configuration;
figure 2a is a section according to line A-A of the detail of figure 2;
figure 2b is the detail of figure 2a in a different configuration;
figure 3 is the detail of figure 2 in a second operative configuration;
figure 3a is a section according to line B-B of the detail of figure 3.

With reference to the figures of the drawings, the motorised lock of the present invention comprises at least a bolt 2, which can be displaced between an open position and a closed position. The positions which the bolt 2 can take up are thus described in reference to the possibility or impossibility of opening a door or similar element on which the lock is mounted. The bolt 2 can be, for example, mobile between a closed position, in which it projects with respect to the door by a portion thereof which is sufficient to engage it in a seating made in a fixed structure, such as a wall or a door frame, and an open position in which the bolt 2 is not engaged in the seating. For other bolt 2 conformations, the open and closed positions can of course be differently defined.
The motorised lock comprises first means 4, 5 for activating the bolt 2, which means comprise a worm screw 4, having a longitudinal rotation axis x, and a nut 5 coupled with the worm screw 4. The worm screw 4 preferably receives drive from an electric gear reducer 40 which is schematically represented in figure 1. The nut 5 is associated to the bolt 2 in such a way that a rotation of the worm screw 4, by inducing a displacement of the nut 5 along the longitudinal axis x, causes a consequent displacement of the bolt 2. Figure 1 shows a preferred embodiment of the lock, in which the bolt 2 moves along a vertical direction (with reference to the orientation of the figure). The nut 5 is associated to a bent edge 10a of a plate 10 which connects the nut 5 to the bolt 2. The nut 5, the plate 10 and the bolt 2 are slidable along a vertical direction which is parallel to the longitudinal axis x of the worm screw 4, but it is obviously possible to use any mechanism of known type which changes the orientation of the movement direction of one of these elements.
The lock further comprises second means 7, 11-15 for activating the bolt 2, which comprise a mechanism predisposed to activate the bolt 2 to displace it. In the preferred embodiment of the lock, the second means 7, 11-15 are mechanical, in order at least to enable displacement of the bolt into the open position should the gear reducer 40 be faulty. The mechanical means for activating preferably comprise a mechanism constituted by a gear wheel 11 and a rack 12. The rack 12 is associated to the bolt 2 by means of the plate 10 and a mobile element 7. The gear wheel 11 is activatable in rotation, typically by a usual lock barrel 14 which acts on a geared sector 15 enmeshing with the gear wheel 11.
The activating of the barrel 14 by the key causes a rotation of the gear wheel 11 and a translation of the rack 12 which in turn causes a displacement of the bolt 2 by means of the plate 10 and the mobile element 7.
The nut 5 can change configuration between a coupled configuration, in which it is coupled with the worm screw 4, and an uncoupled configuration, in which it is not coupled with the worm screw 4 and it is freely slidable along the worm screw 4 itself.
All of the described elements are closed by a containment frame 100 which in figure 1 is represented with a frontal portion thereof (with respect to the orientation of figure 1) removed.
The nut 5 comprises a first body 51, provided with a housing 52. In this housing 52 at least two spheres 53 are housed, which spheres 53 project from the housing 52 in such a way as to be slidable along the thread of the worm screw 4, realising a coupling between the worm screw 4 and the nut 5. The thread of the worm screw 4 is not shown in the figures.
The nut 5 further comprises a second body 54. The second body 54 is provided with striker surfaces 55 predisposed to be positioned in contact with the spheres 53 and to prevent a free rotation of the spheres 53 about the longitudinal axis x of the worm screw 4. The second body 54 is mobile between an engaged position (figures 2, 2a and 2b), in which the striker surfaces 55 are in contact with the spheres 53, and a disengaged position (figures 3, 3a) in which the striker surfaces 55 are not in contact with the spheres 53, which are therefore free to rotate about the longitudinal axis x of the worm screw 4. The engaged position of the second body 54 determines the coupling configuration of the nut 5 with respect to the worm screw 4, the disengaged position of the second body 54 determines the uncoupled configuration of the nut 5 with respect to the worm screw 4. Elastic means 56, preferably a helix spring, are predisposed to keep the second body 54 in the engaged position.
The first body 51 is provided with a through-hole in which the worm screw 4 is longitudinally arranged. Preferably the first body 51 and the through-hole exhibit a cylindrical shape which is coaxial to the longitudinal axis x of the worm screw 4. The though-hole is delimited by a lateral surface 57 on which the housing 52 for the spheres 53 is housed. The housing 52 is conformed as an annular channel, open on the lateral surface 57 of the through-hole. A channel 58 is also afforded on the lateral surface 57, which channel 58 is arranged parallel to the longitudinal axis x of the worm screw 4. The channel 58 is preferably a through-channel passing through a lateral wall of the first body 51.
The second body 54 is slidable with respect to the first body 51 in a parallel direction to the longitudinal axis x of the worm screw 4. The second body 54 is provided with a prismatic appendage 59, which is positioned internally of the channel 58 of the first body 51. The prismatic appendage 59 is laterally delimited, at least for a tract thereof, by the striker surfaces 55 and is arranged so that, at the engaged position of the second body 54, the striker surfaces 55 are at least partially facing the housing 52 of the first body 51. The second body 54 is preferably of an annular shape and is arranged coaxially externally of the first body 51. The prismatic appendage 59 extends longitudinally in a parallel direction to the longitudinal axis x of the worm screw 4 and preferably exhibits, at least in the tract laterally delimited by the striker surface 55, a wedge-shaped transversal section.
As can be seen in figures 2, 2a, 2b and 3, the second body 54 is slidable along an upper tract of the first body 51. The prismatic appendage 59, and in particular the portion laterally delimited by the striker surfaces 55, is housed internally of the through channel 58 of the first body 51 and projects at least partially internally of the through-hole delimited by the lateral surface 57. Figures 2, 2a and 2b show the engaged position of the second body 54. In this position the striker surfaces 55 are at least partially facing the housing 52 of the first body 51. In this position, a rotation of the worm screw 4 which draws with it the spheres 53 is not possible, as apart from a determined settling angle, the spheres 53 are arranged in a striking position against the striker surfaces 55. Figures 3 and 3a illustrate the disengaged position of the second body 54. In this position the striker surfaces 55 are external of the housing 52 of the first body 51. In this condition the worm screw 4 is free to rotate with respect to the nut 5, as the spheres 53 can rotate freely internally of the housing 52 about the longitudinal axis x of the worm screw 4, or equivalently the nut 5 can freely slide along the worm screw 4. Figure 3a also shows a tract of guide 59a of the prismatic projection 59 which slides along a channel made in an external surface of the first body 51. The tract of guide 59a of the prismatic appendage 59 is contiguous to the tract laterally delimited by the striker surfaces 55.
As can be seen in figures 2, 2a, 2b and 3, 3a, the second body 54 is provided with two prismatic appendices 59, which are arranged in diametrically opposite positions with respect to the longitudinal axis x of the worm screw 4 and are housed in respective channels 58.
The lock of the present invention also comprises means for commanding the change of configuration, coupling or non-coupling of the nut 5 with the worm screw 4. The means for commanding are operatively associated with the second means 7, 11-15 for activating the bolt 2, so that an activation of the second means 7, 11-15 induces an action of the means for commanding.
The means for commanding comprise a mobile element 7, mechanically associated to the second means for activating the bolt 2, which mobile element 7 is predisposed to interact with the nut 5, moving between at least a non-operative position, in which it does not interact with the nut 5, and an operative position, in which it displaces the second body 54 into the disengaged position. The mobile element 7 is constituted by a shaped plate which is mobile on a parallel plane to the movement plane of the plate 10. The mobile element 7 is drawn along a parallel direction to the longitudinal axis x of the worm screw 4, at least in one direction, by the rack 12 activated by the cylinder 14. The mobile element 7 exhibits a prismatic projection 71 predisposed to enter into contact with the prismatic appendage 59 of the second boy 54 at least in the operative position of the mobile element 7 itself. By acting on the second means 7, 11-15 for activating the bolt 2, or by rotating the barrel 14, there is an upwards translation of the rack 12 (reference is made to an action aimed at bringing the bolt 2 from the closed position to the open position without having recourse to the use of the first means for activating 5, i.e. the worm screw 4 and the nut 5). The translation of the rack 12 pushes the mobile element 7 upwards. The prismatic projection 71 of the mobile element 7 enters into contact with the prismatic appendage 59 of the second body 54 of the nut 5. The upwards run of the mobile element 7 brings the second body 54 of the nut 5 into the disengaged position and thus the nut 5 into the disengaged position with respect to the worm screw 4. At the end of the first tract of run, necessary for bringing the second body 54 of the nut 5 into the disengaged position, indicated by letter s in figure 1, the mobile element 7 strikes the bent edge 10a of the plate 10. In these conditions, the further translation of the rack 12 pushes upwards the mobile element 7 and the plate 10, displacing the bolt 2 from the closed position into the open position.
An opposite action on the second means 7, 11-15 for activating the bolt 2, i.e. a rotation of the barrel 14 to bring the bolt 2 from the open position to the closed position without using the worm wheel 4 and the nut 5, leads to a downwards translation of the rack 12. At the end of a tract of empty run, indicated by t in figure 1, the rack 12 is newly in a striking position against the mobile element 7, and pushes the mobile element 7 downwards. The downwards movement of the mobile element 7 brings the bolt 2 from the open position to the closed position.
The lock of the invention offers important advantages. It is simple to realise, economical and extremely precise and reliable in operation. An important advantage of the lock is its safety, as it enables the bolt to be moved into the open position even where the worm wheel is jammed, thus practically entirely removing risks of jamming or blocking of the bolt in the closed position. This makes the locked particularly versatile, as thanks to its safety of use it can be used for a whole range of various applications.

Claims

A motorised lock, comprising:
at least a bolt (2) which can be displaced between an open position of a door and the like and a closed position thereof;

first means (4, 5) for activating the bolt (2), comprising a worm screw (4), having a longitudinal rotation axis (x), a nut (5) which couples with the worm screw (4) and which is associated to the bolt (2) so that a rotation of the worm screw (4) induces a displacement of the nut (5) along the longitudinal axis (x) and brings about a consequent displacement of the bolt (2);

second means (7, 11, 12, 14, 15) for activating the bolt (2), comprising a mechanism predisposed to activate and thus displace the bolt (2);

characterised in that the nut (5) is able to vary a configuration thereof between a coupled configuration, in which the nut (5) is coupled with the worm screw (4), and a non-coupled configuration, in which the nut (5) is not coupled with the worm screw (4) and is freely slidable along the worm screw (4).
The lock of claim 1, characterised in that it comprises means for commanding, predisposed for commanding variations of configuration of the nut (5), which means are operatively associated with the second means (7, 11, 12, 14, 15) for activating the bolt (2), in order that an action of the second means (7, 11, 12, 14, 15) for activating induces an action of the means for commanding.
The lock of claim 1, characterised in that the nut (5) comprises: a first body (51), provided with a housing (52) in which at least two spheres (53) are housed, which spheres (53) project from the housing (52) in order to ride along the thread of the worm screw (4), realising a coupling between the worm screw (4) and the nut (5); a second body (54) having striker surfaces (55) which are predisposed to be positioned in contact with the spheres (53) and to prevent a free rotation of the spheres (53) about the longitudinal axis (x) of the worm screw (4), the second body (54) being mobile between an engaged position, in which the striker surfaces (55) are in contact with the spheres (53) and the nut (5) is in a coupled configuration, and a non-engaged position, in which the striker surfaces (55) are not in contact with the spheres (53) and the spheres (53) are free to rotate about the longitudinal axis (x) of the worm screw (4) and the nut (5) is in a non-coupled configuration; elastic means (56) being predisposed to keep the second body (54) in the engaged position.
The lock of claim 2 or 3, characterised in that the means for commanding comprise a mobile element (7), mechanically associated to the second means (11, 12, 14, 15) for activating the bolt (2), which bolt (2) is predisposed to interact with the nut (5) by displacing between at least one non-operative position, in which the mobile element (7) does not interact with the nut (5), and an operative position, in which the mobile element (7) moves the second body (54) into the non-engaged position.
The lock of claim 3, characterised in that the first body (51) is provided with a through-hole in which the worm screw (4) is arranged longitudinally, the through-hole being delimited by a lateral surface (57), in which the housing (52) for the spheres (53) is afforded, and a channel (58) arranged parallel to the longitudinal axis (x) of the worm screw (4).
The lock of claim 5, characterised in that the second body (54) is slidable with respect to the first body (51) in a parallel direction to the longitudinal axis (x) of the worm screw (4) and is provided with a prismatic appendage (59) which is positioned inside the channel (58) of the first body (51), which prismatic appendage (59) is laterally delimited, at least for a tract thereof, by the striker surfaces (55), the prismatic appendage being arranged in such a way that, at the engagement position of the second body (54), the striker surfaces (55) are at least partially facing the housing (52) of the first body (54).
The lock of claim 6, characterised in that the prismatic appendage (59), in the at least a tract thereof laterally delimited by the striker surfaces (55), exhibits a wedge-shaped transversal section, the channel (58) passing through a lateral wall of the first body (51).
The lock of claim 4 or 7, characterised in that the mobile element (7) exhibits a prismatic projection, predisposed to enter into contact with the prismatic appendage (59) of the second body (54) at least in the operative position of the mobile element (7).