Electric lock with multiple-function spring

0001The present invention relates to an electric lock with multiple-function spring.

0002Electrically operated locks suitable to be applied to doors for accessing spaces such as rooms, offices and apartments use a component that is provided with a code as an access key.

0003This component is generally a card that can contain a microprocessor or can be provided with a magnetic strip: in any case, its purpose is to store a code that is correlated to the lock to be operated.

0004The door protected with this type of lock generally has an internal handle (or knob), which acts directly on the locking element of the lock, always allowing to open said lock from the inside.

0005For access from the outside, it is necessary to insert the card in an appropriately provided reader (or, more generally, to insert the component in an appropriately provided receptacle of a respective decoding assembly), which enables a handle (or knob), located on the outside of the door, to move the locking element.

0006The apparatuses normally used to enable opening when the lock has received the correct access code are constituted by a plurality of components: the high complexity of the apparatus makes malfunctions more likely, and said malfunctions moreover entail high maintenance costs, indeed because of the need to disassemble and reassemble the many parts, which are often small.

0007<patcit id="pcit0001" dnum="DE10225490A1"><text>DE 102 25 490 A1</text></patcit> discloses an electric lock as defined in the preamble of claim 1.

0008<patcit id="pcit0002" dnum="EP0861959A2"><text>EP 0 861 959 A2</text></patcit> also discloses a lock.

0009The aim of the present invention is to obviate the above-mentioned drawbacks and to meet the mentioned requirements, by providing an electric lock with multiple-function spring that is constituted by a small number of simple elements, which can be easily operated manually in case of failure of the electric power supply.

0010Within this aim, an object of the present invention is to provide an electric lock that is simple, relatively easy to provide in practice, safe in use, effective in operation, and has a relatively low cost.

0011This aim and this and other objects that will become better apparent hereinafter are achieved by the present electric lock with multiple-function spring, as defined in claim 1.

0012Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment of an electric lock with multiple-function spring, illustrated by way of non-limiting example in the accompanying drawings, wherein: <ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">Figure 1</figref> is a perspective view of a lock according to an embodiment of the invention;</li><li><figref idref="f0002">Figure 2</figref> is a sectional view, taken along a longitudinal plane that passes through the axis of the stem, of a lock according to an embodiment of the invention;</li><li><figref idref="f0003">Figure 3</figref> is a front view of a lock according to an embodiment of the invention in the closure position;</li><li><figref idref="f0004">Figure 4</figref> is a front view of a lock according to an embodiment of the invention in the electric opening position;</li><li><figref idref="f0005">Figure 5</figref> is a front view of a lock according to an embodiment of the invention in the emergency manual opening position.</li></ul>

0013With reference to the figures, the reference numeral 1 generally designates an electric lock with multiple-function spring.

0014Each lock 1 is constituted by a fixed body 2, from which a stem 3 protrudes outward (the knob or handle for opening from the outside is connected to said stem). The stem 3 has, at its base, a plate 4, which can rotate on a sleeve 5, the upper edge 6 of which rests on a contrast plate 7. The sleeve 5 is associated with the locking element, not shown in the figure, and therefore a rotation thereof entails a corresponding retraction (or protrusion) of said locking element; the sleeve 5 is constantly associated with the internal handle.

0015The plate 4, the sleeve 5 and the contrast plate 7 have respective notches 8, which are substantially shaped in a similar manner.

0016With respect to the assembly configuration, a slider 9 is located below the plate 4 and the sleeve 5, can slide on a respective linear guide, and is provided with a cylindrical pin 10 that is substantially parallel to the axis of the stem 3.

0017A spring 11 is constituted by a central portion 12, which forms a cylindrical winding of metal turns, and by two linear arms 13. The central portion 12 is fitted on the pin 10 and covers it completely, while the two arms 13 are respectively coupled within a fixed part of the body 2 and engaged on a worm screw 14, between two successive crests 15.

0018The worm screw 14 is arranged laterally with respect to the slider 9 and is parallel to the linear guide of the slider 9; a first end of the worm screw rests in a fixed seat 16 of the body 2 and a second end is rigidly coupled to the shaft of an electric motor 17.

0019A magnet 18 is fixed to the upper end of the slider 9 and is designed to retain a roller 19 by magnetic attraction in close contact with the slider 9.

0020The operation of the invention is as follows: when the lock 1 is closed, the stem 3 is free, and therefore any rotation thereof imparted by a rotation of the knob (or handle) entails no motion of the locking element (situation shown in <figref idref="f0003">Figure 3</figref>).

0021As a consequence of the insertion of the component provided with a code (generally a card with a magnetic strip or provided with an integrated memory circuit) in an appropriately provided receptacle of the decoding assembly (generally a card reader), and if the code is the one enabled for opening, the motor 17 is supplied with power so that it turns the worm screw 14. The arm 13, arranged between two successive crests 15 of the worm screw 14, is transferred from the configuration shown in <figref idref="f0003">Figure 3</figref> (arm 13 proximate to the motor 17) to the configuration shown in <figref idref="f0004">Figure 4</figref> (arm 13 proximate to the fixed seat 16).

0022During this motion of the arm 13, the slider 9 is subjected to a translational motion that causes its upper end (the one that accommodates the magnet 18) to face the plate 4, the contrast plate 7, and the sleeve 5. In this situation, the roller 19 is accommodated within the notches 8 of the plate 4, of the contrast plate 7 and of the sleeve 5, which are mutually superimposed.

0023The presence of the roller 19 in this position entails that said roller rigidly couples the plate 4, the contrast plate 7 and the sleeve 5 to each other: in this configuration (<figref idref="f0004">Figure 4</figref>), a rotation of the outer knob (or handle), which induces a similar rotation of the stem 3, of the plate 4 and of the contrast plate 7, also rotates the sleeve 5, entailing the actuation of the locking element and therefore the opening of the lock 1.

0024If it is necessary to open the lock 1, in case of an electric power supply failure, it is necessary to access a bit 20, which is located below the slider 9.

0025Access may be possible only by having an appropriately provided key, by means of which it is possible to turn the bit 20, with a consequent action of the inclined surface 21 on the lower surface of the slider 9 that entails an upward translational motion of the slider 9 (as shown in <figref idref="f0005">Figure 5</figref>).

0026The spring 11 undergoes a deformation, reducing the angle between its two arms 13 (because the arm 13 remains engaged in the worm screw 14 proximate to the motor 17), tending to return the slider 9 downward (return translational motion prevented by the presence of the inclined surface 21).

0027The upward translational motion of the slider 9 entails the engagement of the roller 19 in the notches 8 and therefore allows actuation of the locking element by means of the knob (or handle) fitted on the stem 3.

0028By returning the bit 20 to its initial configuration, the slider 9 again performs a downward translational motion by way of the action of the spring 11, and the rotation of the stem 3 is again independent of the rotation of the sleeve 5.

0029It has thus been shown that the invention achieves the intended aim and object.

0030The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims.

0031In 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 as defined by the appended claims.