Electronic lock including a clutch mechanism

ES 2 189 571 B2

DESCRIPTION

Clutch mechanism for electronic locks.

Object of the invention

The present invention, as expressed in the wording of this specification, consists of a clutch mechanism for electronic locks, which has notable relevant and advantageous characteristics compared to those currently used for the same purpose.

It is an object of the invention to incorporate the clutch mechanism in the inner escutcheon of the lock and thus allow it to be used with a wide variety of mortise locks, even with locks that are already installed.

Placing it on the inner escutcheon provides the advantages of greater security and better aesthetics:

Greater security since it is protected against manipulation from outside and against adverse weather conditions; and better aesthetics since the outer shield does not need extraordinary dimensions to house the clutch mechanisms.

Current state of the art

Electronic locks are characterized by having a mechanical lock that physically fixes the door to the frame and by electronic means to authorize the use of said lock. Electronic media include a reader that allows them to read the data from a code carrier that can have different shapes and different technologies, such as a magnetic card, a proximity card, a memory key. We will call these code carriers a key in a generic way. When a key with valid data is presented, the electronic control allows the external handle to actuate one of the axes of the mechanical lock, either by releasing a lock that prevented the handle from turning, or by activating a clutch. that connects the shaft of the handle to the shaft of the lock.

Mechanical locks can have one or more axes. Some open the latch and are usually operated with a handle or knob. Others close or open the lever and are usually operated by a cylinder, either with a key, or with a rotary knob. The electronic control can control the actuation of one or more of the axes depending on the applications of the lock. In the description that follows, we do not distinguish between one axis and another, nor between handles, knobs, or buttons, using the generic word "handle".

The solutions based on condemnation, although they are simpler, are less safe than those based on clutch since the condemnation must resist any type of efforts that are applied to the handle trying to force it, while the clutch simply does not transmit said forces to the lock.

On the other hand, the handle on the inside of the door must always open the lock to allow exit in an emergency, without the intervention of any electronic control. This feature is called anti-panic.

There are numerous patents for clutch mechanisms for electronic locks that are housed in the outer escutcheon and connect the shaft of the outer handle with the shaft that operates the lock, the latter being permanently connected to the inner handle.

An improvement is to place the clutch on the inside of the door instead of on the outside. It is a safer solution since it is protected from possible manipulations. It is more reliable from an environmental point of view since the interior side tends to suffer less variations in temperature and humidity. It can be more aesthetic since the outer shield does not have to house the clutch mechanism.

Patent EP 0 819 810 claims a clutch placed on the inner escutcheon and which operates the lock through two concentric axes. The first axis is connected to the outside handle. The second shaft is connected to the inside handle and to the nut of a modified cylinder through which it opens the lock.

When installing the lock, the first shaft is inserted into the second, rotating freely inside it.

To engage both shafts, a part is moved axially by projecting a clutch plate through a slot in the second shaft into a slot in the first shaft. The two shafts are thus coupled and allow the outside handle to open the lock.

The problems it presents are due to the forced small diameter of the shafts so that they are compatible with standard locks.

The nuts of mechanical locks have standard sections and are usually square with sides between 7 and 9 mm. The diameters of the concentric shafts described can at most be equal to said dimensions in the case of the second shaft and smaller in the case of the first shaft.

The first problem is a consequence of the efforts that the mechanism supports. When it is engaged, the force suffered by the plate, the groove on one shaft and the groove on the other, is equal to the actuation torque of the lock divided by the radius of the shafts. As this is very small, the stress is very great and wear occurs quickly.

The second problem is also caused by the small diameter of the first shaft, which means that it cannot have more than two grooves to keep its resistance at acceptable minimums, since each groove decreases its section. When the clutch is engaged, the engagement between the two shafts does not take place until the groove of the second shaft faces one of the two grooves of the first shaft. It may therefore be necessary to turn the outer handle unladen up to 180 °, producing an uncomfortable feeling for the user.

Description of the invention

In general terms, the clutch mechanism for electronic locks, which is the object of the invention, solves both of the aforementioned problems while maintaining the advantages of being located on the inner escutcheon and of being able to be adapted to any lock, since the actuation axes have standard dimensions.

By means of a totally different configuration of the clutch, the advantage is achieved that the stresses suffered by the interacting parts is as low as possible and that the idle rotation of the outer handle is minimized. In addition, it allows a very simple assembly.

The electronic lock includes an external shield that supports the key reader and an external control button for activating the locking systems. The inner shield contains the battery-powered electronic control circuit, the

ES 2 189 571 B2 clutch and an internal actuation button.

The clutch mechanism has two concentric shafts, one of which acts on the nut while the other rotates freely with respect to the first when the outer knob with which it is attached is actuated. The inner button or knob is attached to the first shaft.

Both concentric shafts become integral in rotation when the clutch is actuated by an electric motor commanded by a control device connected to the key reader.

There are two drive pieces, one outside and the other inside that are interlocked by means of crenellated projections, determining between them a cavity in which the clutch part rotates freely, which has notches on its periphery into which the projections can be inserted. axial elements of a hooking piece that defines the axially movable element, these projections that previously pass through the inner drive, the latter endowed with corresponding holes. The coupling piece moves by means of a fork and the movement is guided on the cylindrical periphery of an inner shaft integral with the inner square driven by the inner knob.

When the mechanism is disengaged, the hitch part is retracted and the projections of the hitch part do not touch the clutch and therefore the movement is not transmitted to the nut.

When the mechanism is engaged, the coupling part has occupied the most advanced position and the aforementioned projections of the coupling part are inserted in the respective notches of the clutch part and therefore the joint rotation of the concentric shafts occurs, at the same time. turn the outer knob.

To facilitate the understanding of the characteristics of the invention and forming an integral part of this specification, some sheets of plans are attached in whose figures, with an illustrative and non-limiting nature, the following has been represented:

Brief description of the drawings

Figure 1.- Is a schematic front elevation view of a mortise lock placed on a door, including the clutch mechanism object of the invention.

Figure 2.- Is a detailed view of the exploded parts of the clutch mechanism.

Figure 2a.- Represents in front elevation and in profile, the outer drag piece, shown in the figure

2.

Figure 2b.- Represents two other views of the according to the clutch element, according to what is shown in figure 2.

Figure 2c.- Represents two other views of the inner drive piece, according to what is shown in Figure 2.

Figure 2d.- Represents two other views of the coupling piece, according to what is shown in figure 2.

Figure 3.- It is a section of the mechanism when it is not engaged, according to a plane that contains the clutch shaft.

Figure 4.- It is the same section of figure 3, with the mechanism when it is engaged.

Figure 5.- It is a section of the mechanism when it is engaged, along a plane perpendicular to the axis of the clutch.

Figure 6.- It is a cross section similar to figure 5, of a variant embodiment of the mechanism.

Figure 7.- It is a perspective view of the clutch mechanism, with all the assembled parts, according to figure 2, excluding the box and the cover of the mechanism, for their visibility.

Description of the preferred embodiment

Referring to the numbering adopted in the figures and especially to figure 1, we can see how the clutch mechanism for electronic locks, which the invention proposes, is mounted in a mortise lock 1, in which when turning its nut 2 lever and latch move.

The electronic lock is made up of two shields: the outer shield 3 that supports the key reader 4 and an outer button 5; and the inner shield 6 containing the electronic control circuit 7 powered by the batteries 8, the clutch mechanism 9 and an inner button 10.

Two concentric shafts 21 and 26 emerge from the clutch mechanism 9. The first shaft 21 acts on the nut 2 of the lock. The second shaft 26 rotates freely within the first and is partially inserted into the outer button 5 by rotating integral with it.

The inner button 10 always operates the lock since through several pieces it is integral with the axis 21 that acts on the nut 2.

The key reader 4 is electrically connected to the control 7. When a valid key is presented, the control feeds the clutch mechanism motor through cables, making axes 21 and 26 integral for a few seconds, allowing the outer button to 5 open the lock.

The configuration represented in this figure 1 is given by way of example and neither the type of key reader used, nor the exact configuration of the mortise lock, is important. A European type mortise lock has been represented, the axis that acts the lever being actuated, but in the same way it could be the axis that acts the latch, or it could be an American lock or a single axis lock to actuate a latch or a lever.

Now making special reference to figure 2 in which the exploded view of the clutch mechanism is shown, it can be seen that the first shaft 21 is fixed to the outer drive 22 by means of a quadrangular housing and a radial screw (see also figure 2a). The outer drive 22 and the inner drive 23 will engage each other by means of crenellated projections 221 and 231, forming inside a cavity in which the clutch element 27 rotates freely. This element has four notches 272 on its periphery, in the embodiment shown.

The second shaft 26 is inside the first shaft 21 and passes through the outer drive 22 when passing through the hole 222 of the latter and has a thickening 261 that is housed in the hole 271 of the clutch element 27, both with a section that has two flat faces so that they rotate in solidarity.

The inner square 25 is mounted on an inner shaft 24 that has flat faces that are complementary to a gap 232 open in the inner drive 23. The set of first shaft 21, outer 22 and inner 23 drives, inner shaft 24 and inner square 25 rotate integrally and are held together because the box 41 and the cover 42 keep all the pieces at a fixed length thanks to the projections of the outer drive. 22 and inner shaft 24 which are larger in diameter than holes 411 and 421.

ES 2 189 571 B2

However, the assembly formed by the second shaft 26 and the clutch element 27 rotate freely but cannot move axially because their movements are limited by the configuration of the parts described above.

The hitch 28 is a piece that can slide axially on the inner shaft 24 and has four projections 281 that pass through the inner drive 23 through four holes 233 and are also housed in the grooves 223 of the outer drive 22. The profile of these projections 281 is the same as the notches 272 of clutch element 27.

The coupling piece 28 has on its cylindrical periphery, the annular groove 282 in which the two projections 301 of the fork 30 are housed. This fork 30 can oscillate around its axis 302 by acting on its arm 303. The electric motor 51 it moves said arm 303 through a spring 53 and an endless 52.

In figure 3, where a section of the mechanism is shown when it is disengaged, it can be seen how the coupling piece 28 is in its most retracted position, so that the projections 281 do not completely pass through the internal drive 23 and do not touch the clutch element. 27. Under these conditions, if the outer knob 5 is turned, the second shaft 26 and the clutch element 27 will rotate, but will not transmit any movement to the rest of the parts.

In figure 4, where the clutched mechanism is represented, we can see that the coupling piece 28 is in its most advanced position and its projections 281 completely go through the holes 233 and project into the four notches 232 of the clutch element 27, as well as inside the grooves 223 of the outer drive 22, causing both pieces (clutch element 27 and outer drive 22) to rotate integrally.

In the cross section of the mechanism, according to figure 5, which affects the external drive 22, clutch 27 and projections 281 of the collar or coupling piece 28, the interaction of said pieces when they are engaged can be appreciated. Due to the configuration of the mechanism, the clutch points are on the outermost circle. The pieces can be made with a diameter as large as the width of the inner shield 6 of the lock allows, so that the stresses suffered by them are thus reduced.

Figure 6 represents a variant embodiment in which the projections 281 have a round section instead of a trapezoidal one, like the notches 271 of the clutch element 27, having been referenced with the same numbers by adding the suffix "prima". The projections 281 'in this case do not interact with the outer drive 22, which is not necessary because as they pass through the holes 233 of the inner drive 23, they make the latter rotate integrally with the clutch 27 producing the desired effect. The principle of operation is otherwise the same.

The embodiment of figure 5 has the advantage over that shown in figure 6, that the points of application of the forces made by the projections 281 on the clutch element 27 and on the grooves 223 of the outer drive 22 are located in the same plane and at very short distances, which is beneficial to the behavior of the system.

The embodiment of FIG. 6 causes the projections 281 'to undergo bending forces because the points of application of the forces against the clutch are in a different plane from the forces against internal drag. In any case, given the proximity of both planes, the bending forces are not very great. On the contrary, its realization can be cheaper since the forms are simpler.

Other variations can be made by increasing the number of projections 281 or 281 ', to five, six or eight to decrease idle rotation before engaging. There may also be small variations in the shapes of the pieces to facilitate their manufacture, or in the grouping of several of them into one, such as the inner shaft 24 and the inner square 25, or in the decomposition of one into several.

It should also be noted that the mechanism. Clutch can be adapted to different types of lock, for example European locks or American mortise locks or tubular locks provided they can be operated by means of a square. As we had indicated at the beginning of this specification, the mechanism proposed by the invention can be adapted to the axis that acts on the lever, or to the axis that acts on the latch.