EP2760776B1 - Brake device with electromechanical actuation - Google Patents

Description

The invention relates to a braking device for braking an elevator car, a method for braking the elevator car and an elevator system with elevator car and with such a braking device.

The elevator system is installed in a building. It consists essentially of a cabin, which is connected via suspension means with a counterweight or with a second car. By means of a drive which acts selectively on the support means or directly on the car or the counterweight, the car is moved along, substantially vertical, guide rails. The elevator system is used to transport people and goods within the building over single or multiple floors.

The elevator system includes devices to secure the elevator car in the event of failure of the drive or the suspension means. These braking devices are usually used, which can slow down the elevator car on the guide rails in case of need.

From the EP2058262 is such a braking device known. This brake device can be actuated electromagnetically, wherein a pawl retains a brake module against a delivery force. The braking device is activated by the pawl is disconnected from the brake module. To reset the latch must be latched again.

From the EP 2 194 014 is also known such a braking device.

The invention aims to provide a braking device which can cause braking of the elevator car. The braking device should be electromechanically actuated and it should be easy to reset. It should also be based on proven technology and be simple.

The solutions described below meet at least some of these requirements. Proposed is an elevator braking device, which is suitable for delaying and holding an elevator car in cooperation with a braking surface in case of need. Advantageously, this elevator braking device is arranged on a running body of the elevator, for example, the elevator car and they can cooperate with guide rails, which are provided for this purpose with braking surfaces. The braking surfaces can also be used multifunctionally for guiding the driving body. Analogously, the elevator brake device can also be arranged in the region of the drive and the braking surface may be a surface of a brake disc or a rope, such as a rope surface.

The elevator brake device includes at least one brake element. The braking element is self-reinforcing. It includes an eccentric-like shape or another amplification curve. Self-reinforcing means that the brake element, after it has been brought to the braking surface with an initial force, automatically moves by a relative movement between the elevator brake device and the braking surface in a braking position. The brake element is preferably rotatably arranged in a brake housing by means of a pivot bearing and has a curve shape which is designed so that a radial distance of the curve from the pivot bearing increases over a rotation angle. As a result, self-reinforcement is achieved when the braking element is rotated. The initial force needed to bring the braking element to the braking surface is provided by a force accumulator. The energy accumulator is preferably a tensioned spring. Of course, pneumatic, hydraulic or, depending on the field of application, also weight-based energy accumulators come into question.
The elevator brake device further includes an actuator which can act on the brake element. The actuator keeps the brake element in normal operation in a first operating position. He presses this, the brake element against the force of the energy storage of the braking surface away or he keeps the brake element spaced from this. This allows an unrestrained method of the driving body. If necessary, the actuator releases the brake element, whereby the energy accumulator can bring the brake element in a second operating position and with what a pressing of the brake element can be made to the braking surface. As soon as the brake element is pressed against the braking surface, it is entrained by the relative movement between the elevator brake device and the braking surface. As a result of this entrainment, the brake element is again moved in such a way that the brake element moves the actuator back into a reset position corresponding to the first operating position. The actuator is thus back to its original position corresponding to normal operation.
This has the advantage that a retaining mechanism of the actuator, such as a solenoid or a pawl, only needs to be turned on to fix the actuator in this, the first operating position corresponding reset position. Thus, the actuator is reset without further return work. The holding mechanism can therefore be designed inexpensively.

In one embodiment, the brake element is installed in the brake housing. The energy accumulator and the actuator are designed to be placed over the brake housing on the Intervene braking element. Advantageously, in this case the brake housing is horizontally displaceable, for example, stored and held in a support and the actuator is also stored in this support.
This is advantageous because many elevator brake devices used today already have a brake housing, which in many cases is already mounted horizontally displaceable. The proposed embodiment can thus be realized inexpensively, since in addition to known elevator brake devices only the brake housing must be fixed by an actuator and delivered by a force storage.

In another embodiment, the brake element itself is slidably mounted in the brake housing, so that it can be delivered perpendicular to the braking surface. The energy accumulator and the actuator are designed to act on the brake element. For example, in this case the brake element is mounted horizontally displaceable in the brake housing. The actuator, which is advantageously also mounted in the brake housing now allows that the brake element can be delivered in the brake housing to the braking surface. Due to the self-reinforcing property of the brake element, the brake element is reset or pushed back during subsequent operation in the brake housing and the actuator can follow this return movement, bringing it back to its original normal position.

The brake element of the elevator brake device is rotatably mounted in a variant embodiment by means of the pivot bearing in the brake housing. The curve shape of the braking element defines a central clamping region which is eccentric or shaped, for example, in relation to the rotary bearing, so that a distance from the rotary bearing to following curve sections of the clamping region increases over a rotation angle. Thus, in a relative movement between the elevator brake device and the braking surface, a self-reinforcement, as an axis of the pivot bearing is pushed back during rotation of the brake element. After a first shift the axis of the pivot bearing again reaches its original, the first operating position corresponding position and the actuator can follow this return movement, bringing it back to its original normal position.
The further relative movement between the elevator brake device and the brake surface causes the brake element to be further rotated, which results in a further reinforcement. This further reinforcement first causes, for example, one of the braking surfaces opposite brake plate is drawn to the brake counter surface and is further stretched until a sufficient clamping force and corresponding braking force is reached. The further reinforcement of course also causes the axis of the pivot bearing is pushed back further.
Since the actuator has usually already reached its, the first operating position corresponding position between the brake element, or brake housing, and actuator in this operating position a game arise.
Alternatively, of course, the holding mechanism may be elastically mounted to allow a corresponding forcing.

In one embodiment variant, the brake element has a first braking region, which adjoins the central clamping region. This is advantageous at higher speeds. The eccentric does not have to roll over an entire braking distance, but the braking area terminates the rolling and amplifying process and the driving body is stopped by the braking area and the braking force of the opposing brake plate. The brake element preferably has a second brake area, which adjoins an end of the middle clamping area opposite the first brake area. Thus, a double-acting elevator brake device can be provided, since according to a direction of travel, the brake element is necessarily moved correctly.

In an alternative embodiment variant, the brake element has a brake shoe instead of the first brake region. This is, for example by a control eccentric of the brake element, pressed by rotation of the same to the braking surface.

In one embodiment, the elevator brake device further includes a brake plate. This brake plate is arranged such that the braking surface, or a corresponding guide rail between the brake element and the brake plate can be clamped. Advantageously, the brake plate is fastened by means of at least one brake spring in the brake housing. The brake spring is designed according to a braked mass of the vehicle. Taking into account the geometric design of the brake element and a resulting deflection of the brake spring, a stiffness or spring constant and bias thereof can be determined. Thus, on the one hand by means of a form of the braking element, the engagement and restoring functionality can be solved and on the other hand, a braking force can be adjusted by means of the design of the brake plate with brake spring.

In one embodiment, the actuator includes an electro-magnet with an anchor plate. In the first operating position, the anchor plate is applied to the electro-magnet and it is held by this electromagnetically. Thus, the actuator is held in the first operating position and the brake element is held accordingly with a drive-through clearance to the braking surface. As passage passage an air gap is called in the Operating position between brake element and brake rail is present to allow a method of the elevator car or the counterweight. The anchor plate is located directly on the electromagnet. Therefore, a small current is enough to maintain a required magnetic field and holding force. If the circuit of the electromagnet is interrupted, the magnetic field drops and the brake element can be delivered to the braking surface. As already explained above, the actuator is moved by the relative movement between the elevator brake device and the braking surface in such a way that it returns to the reset position corresponding to the first operating position. The armature plate, is brought into contact with the electro-magnet regardless of a Bestromungszustand of the electromagnet. Thus, a subsequent reset of the elevator braking device can be done easily. It can only be turned on the circuit to the electromagnet. Since the anchor plate is already applied to the electromagnet, the anchor plate and thus the actuator is set immediately. There is no need to overcome an air gap between the electromagnet and the armature plate. By a backward movement of the driving body and thus the elevator brake device, the brake element can be moved from the preloaded braking position directly into the first operating position.

In one embodiment, the actuator is adjustable to allow adjustment of the first operating position. Thus, for example, a passage clearance between the brake surface and brake element can be accurately adjusted.

In one embodiment, the actuator includes an auxiliary weight. This auxiliary weight always presses the actuator against the action of the force accumulator and thus it can hold a driver, preferably a locking roller, in contact with the brake element or the brake housing. For example, the auxiliary weight may already be the weight of the anchor plate or, of course, it may be an additional weight element. Alternatively or additionally, an auxiliary spring can be used which holds the driver, preferably the locking roller in contact with the brake element, or the brake housing.

Overall, such an elevator braking device in an elevator system with an elevator car and advantageously directly on the same or grown. The braking surface is directly a part of the guide rail and the elevator brake device clamps a web of the guide rail for the purpose of holding and braking.
Advantageously, the elevator car is provided with two elevator brake devices and these elevator brake devices can act on two guide rails arranged on opposite sides of the elevator car. Advantageously, these are two Elevator brake devices are coupled to a synchronization bar, and advantageously both elevator brake devices each comprise an actuator. In this way, a safety of the elevator brake devices can be increased since, if one of the actuators fails, the remaining actuator synchronously actuates both elevator brake devices via the synchronization rod. This prevents unilateral braking.

Fig. 1

eine schematische Ansicht einer Aufzugsanlage in der Seitenansicht,

Fig. 2

eine schematische Ansicht der Aufzugsanlage im Querschnitt,

Fig. 3

eine schematische Ansicht einer Aufzugs-Bremseinrichtung in einer ersten Betriebstellung,

Fig. 4

die Aufzugs-Bremseinrichtung von Fig. 3 in einer zweiten Betriebsstellung,

Fig. 5

die Aufzugs-Bremseinrichtung von Fig. 3 in einer der ersten Betriebsstellung entsprechenden Rückstellposition,

Fig. 6

die Aufzugs-Bremseinrichtung von Fig. 3 in einer Klemmstellung,

Fig. 7

die Aufzugs-Bremseinrichtung von Fig. 3 in einer Bremsstellung,

Fig. 8

eine perspektivische Ansicht einer ausgeführten Aufzugs-Bremseinrichtung,

Fig. 9

eine Rückansicht der Bremse von Fig. 8 in der ersten Betriebstellung,

Fig. 10

eine Draufsicht der Bremse von Fig. 8 in der ersten Betriebstellung,

Fig. 11

eine Rückansicht der Bremse von Fig. 8 in der zweiten Betriebstellung,

Fig. 12

eine Draufsicht der Bremse von Fig. 8 in der zweiten Betriebstellung,

Fig. 13

eine Rückansicht der Bremse von Fig. 8 in der Bremsstellung,

Fig. 14

eine Draufsicht der Bremse von Fig. 8 in der Bremsstellung.

In the following, the invention will be explained by way of example with reference to exemplary embodiments in conjunction with the figures.
Show it:

Fig. 1

a schematic view of an elevator system in the side view,

Fig. 2

a schematic view of the elevator installation in cross section,

Fig. 3

a schematic view of an elevator braking device in a first operating position,

Fig. 4

the elevator braking device of Fig. 3 in a second operating position,

Fig. 5

the elevator braking device of Fig. 3 in a reset position corresponding to the first operating position,

Fig. 6

the elevator braking device of Fig. 3 in a clamping position,

Fig. 7

the elevator braking device of Fig. 3 in a braking position,

Fig. 8

a perspective view of an executed elevator braking device,

Fig. 9

a rear view of the brake of Fig. 8 in the first operating position,

Fig. 10

a top view of the brake of Fig. 8 in the first operating position,

Fig. 11

a rear view of the brake of Fig. 8 in the second operating position,

Fig. 12

a top view of the brake of Fig. 8 in the second operating position,

Fig. 13

a rear view of the brake of Fig. 8 in the braking position,

Fig. 14

a top view of the brake of Fig. 8 in the braking position.

In the figures, the same reference numerals are used across the figures for equivalent parts.

Fig. 1 shows an elevator system 1 in an overall view. The elevator installation 1 is installed in a building and serves to transport persons or goods within the building. The elevator installation includes an elevator car 2, which can move up and down along guide rails 6. The elevator car 2 is provided for this purpose with guide shoes 8, which leads the elevator car as closely as possible a predetermined route along. The elevator car 2 is accessible from the building via doors. A drive 5 serves to drive and hold the elevator car 2. The drive 5 is arranged for example in the upper part of the building and the car 2 is suspended with support means 4, for example suspension ropes or carrying strap on the drive 5. The support means 4 are on the drive 5 further to a Counterweight 3 led. The counterweight compensates for a mass fraction of the elevator car 2, so that the drive 5 has to compensate for the main thing only an imbalance between the car 2 and counterweight 3. The drive 5 is arranged in the example in the upper part of the building. It could, of course, also be arranged at another location in the building, or in the area of the car 2 or the counterweight 3.
The elevator car 2 is equipped with a braking system which is suitable for securing and / or decelerating the elevator car 2 during an unexpected movement or at overspeed. The brake system is arranged in the example below the car 2 and it is electrically controlled (not shown). A mechanical speed limiter, as it is commonly used, can therefore be omitted.

Fig. 2 shows the elevator system of Fig. 1 in a schematic plan view. The brake system includes two elevator brake devices 20. The two elevator brake devices 20 are coupled in this example by means of a synchronization rod 15 so that the two elevator brake devices 20 are actuated together. Thus, an unintentional one-sided braking can be avoided. The two elevator brake devices 20 are preferably of identical or mirror-symmetrical design and, if necessary, they act on the guide rails 6 arranged on both sides of the car 2. For this purpose, the guide rails 5 contain braking surfaces 7 which, in cooperation with the elevator brake devices 20, can cause the elevator car 2 to brake.
On a synchronization rod 15 can also be omitted. However, then electrical synchronization means are recommended which ensure a simultaneous triggering of both sides of the elevator car arranged elevator brake devices 20.

Fig. 3 shows a possible embodiment of an elevator braking device 20. The elevator brake device 20 is designed to cooperate with a braking surface 7. This braking surface 7 is a part of the guide rail 6.
The elevator brake device 20 is in a first operating position B1. In this position, the elevator brake device 20 does not brake, ie the elevator car 2 can be moved. The elevator brake device 20 includes a brake housing 21 which is slidably disposed in a support 9 via a sliding connection. The sliding connection essentially comprises a sliding guide 23, which is arranged in the support 9 and the brake housing 21 is mounted via a guide rod 22 in this sliding guide 23. Of the Support 9 is attached to the elevator car 2 or it is a part of the elevator car 2. The elevator car 2 and thus the support 9 is by means of guide shoe 8 (see Fig. 1 and 2 ) guided along the guide rail 6.
Of course, other types of sliding joints are possible. For example, the brake housing 21 could slide in slideways of the support 9 or it could be connected to the elevator car 2 or support 9 via a pivot bearing. Thus, the brake housing 21 is horizontal, or perpendicular to the braking surface 7, slidably disposed. In the brake housing 21, a brake element 25 is arranged.
The brake element 25 is connected to the brake housing 21 via a rotary bearing 28. In the illustrated embodiment, the brake member 25 includes a clamping portion 26. In the first operating position (B1), the brake element 25 is in a central position. This central position is adjusted for example by a centering spring 42. The centering spring 42 engages the brake element 25 and pulls it with little force in the middle position, as in the Fig. 3 seen. The clamping region 26 is designed with respect to a longitudinal axis 28a of the rotary bearing 28, or describes a curve shape such that a radial distance R increases from the longitudinal axis 28a to the clamping region 26, starting from the central position, over a rotation angle (α). At the clamping area 26 includes a brake area 27.1, 27.2. The braking region 27.1, 27.2 snuggles against this as a tangential continuation of the clamping region 26. In the example, the brake element 25 includes a first brake area 27.1 and a second brake area 27.2, which are arranged at both ends of the clamping area 26. This brake element is intended for braking in both directions. The clamping region 26 is preferably provided with a Randrierung or with transverse grooves to allow a good gripping of the clamping portion 26 on the braking surface 7. The brake area 27.1, 27.2 is designed as a brake pad. It may include a special brake material, such as ceramic, sintered material, or hardened brake shoes.
In support 9, an actuator 32 and a force storage 24 is arranged. The actuator 32 forms a stop for the brake housing 21 and thus for the brake element 25 via a locking roller 33 or a corresponding driver. The force accumulator 24, in the example a compression spring, presses the brake housing 21 and thus the brake element 25 against the actuator 32 determines the position of the brake member 25 with respect to the guide rail 6 and thus with respect to the braking surface 7. With suitable adjustment means, the position of the actuator 32 and thus the position of the brake element 25 can be set at best. The actuator 32 is fixed by a retainer, in the example in the form of an electro-magnet 36 and associated anchor plate 37.
Next is located opposite the brake element 25, a brake plate 30. The brake plate 30 is disposed in the brake housing 21 and supported by brake springs 31 in this. The Brake plate 30 is arranged such that the guide rail 6 projects into the space defined by the brake plate 30 and brake member 25 intermediate space. A distance between brake plate 30 and brake element 25 is selected in the first operating position B1 so that a sufficient clearance S1, S1 'is ensured for the guide rail 6, or to the corresponding braking surfaces. Of course, the brake plate 30 could of course also be designed as a solid counter-covering, without resilient support by means of brake springs, or it could be designed in the form of a brake wedge. This would allow, for example, an additional, direction-dependent gain of a braking force.
A pressing force F24 of the force accumulator 24 is selected so that in the case of actuation, the brake element 25 is pressed so strongly against the braking surface 7 that it is safely taken in a relative movement between the brake surface 7 and the brake housing 21. In one embodiment, this requires a force of at least about 85 N (Newton). Taking into account friction losses, as for example in a coupling of two elevator braking devices 20, as in the example of Fig.1 and 2 shown by means of synchronization rod 15, an effective retention force F32 of the actuator 32 in the example is about 1000 N (Newton). Thus, there is sufficient security that the elevator brake device 20 is not actuated because of vibrations and at the same time the energy accumulator 24 can be dimensioned sufficiently strong that in any case a safe operation of the elevator brake device 20 can take place.
Considering a lever ratio of about 1: 4 at the actuator 32 results in a required magnetic holding force F36 of about 250N. A corresponding electro-magnet 36 has a diameter of about 25 mm (millimeters) at a height of about 20 mm (millimeters). Such an actuation system can thus be realized with small dimensions. It takes up little space. Of course, these values are informative. They are determined by the skilled person due to the geometric and constructive design of the parts involved.

To operate the elevator brake device 20 is in a first step, as in the Fig. 4 can be seen, the electro-magnet 36 is de-energized and the armature plate 37 together with the complete actuator 32 is free. As a result, the pressing force F24 of the force accumulator 24 is released and he pushes the brake housing 21 and thus the brake element 25 with the corresponding pressing force F24 'against the guide rail 6, and the corresponding braking surface 7. The longitudinal axis 28a of the pivot bearing 28 is thus by the amount of Passage game S1 delivered. In the example, the entire brake housing 21 has moved along with the brake element 25. Therefore, a passage clearance S2 on the opposite side of the guide rail is increased accordingly.

In a following relative movement between the braking surface 7 and the brake housing 21 causes the contact force F24, that the clamping portion 26 is taken from the braking surface 7. The clamping region 26 is advantageously structured or knurled for this purpose. By the entrainment of the clamping region 26, the brake member 25 rotates about the rotation axis 28. The longitudinal axis 28a, according to the increase in the radial distance R from the longitudinal axis 28a to the clamping portion 26, pushed back in the direction of the original first operating position. In Fig. 5 can be seen how in the course of pushing back the longitudinal axis 28a and thus also the brake housing 21 again reaches the position corresponding to the first operating position. Because of the weight adjustment of the actuator 32, the anchor plate 37 is in turn on the electro-magnet 36. The weight adjustment results from the arrangement of the lever 35, the anchor plate 37 and the influence of a possible auxiliary spring 39 or a corresponding auxiliary weight 38th

However, the clamping portion 26 continues to rotate as in FIG Fig. 6 can be seen, and finally pushes the brake housing 21 back so that the brake plate 30 also bears against the guide rail 7 and he continues to turn until the brake area is reached 27.1, as in Fig. 7 shown. Up to this operating point, the longitudinal axis 28a and thus also the brake housing 21 has been set back further, as a result of which the brake springs 31 of the brake plate 30 are finally tensioned. As a result of the pressure force of brake plate 30 and brake region 27.1 thus constructed on the braking surfaces 7 of the rail 6, the elevator car 2 is finally braked.
As in the 6 and 7 can be seen, after the actuator 32 has reached its reset position, ie when the armature plate 37 rests against the electro-magnet 36, the brake housing 21 at best by the actuator 32, and its locking roller 33 are moved away. It is crucial that the actuator 32 is again in this braking position of the elevator brake device 20 in one of the first operating position corresponding reset position B3.
If now the elevator braking device 20 is to be reset, a holding current of the electro-magnet 36 can be turned on first. As a result, the actuator 32 is fixed or fixed without the electro-magnet 36 still has to apply an air gap or otherwise return energy.
To reset only the elevator car 2 has to be reversed opposite to the previous direction of braking. As a result, the brake member 25 is turned back and the brake housing 21 by the power storage 24 and the fixed actuator 32 in the first operating position B1, as in Fig. 3 shown set. The brake element 25 itself is brought, for example by the centering spring 42 back into its central position.
Another embodiment is in the 8 to 14 shown. In principle, in this embodiment, a safety gear is integrated in the elevator braking device, as for example from the disclosure DE2139056 is known. The elevator brake device 20 is integrated into a structure of the elevator car 2. The elevator car 2 also includes the guide shoe 8 which is provided for guiding the elevator car along guide rails (not shown). The elevator brake device 20 includes a brake element 25 with a clamping region in the form of a control eccentric 25.1 and brake shoes 25.2, which are rotatably mounted in the brake housing 21 about a rotation axis 28. A synchronization rod 15 with synchronization lever 16 connects the two elevator brake devices 20 arranged on both sides of the elevator car 2. This ensures that the two elevator brake devices 20 engage with each other. At this synchronization rod optionally centering parts (not shown) may be provided which set a center position of the control eccentric 25.1 and it can switch (not shown) are provided, which can determine a rotation of the synchronization rod and thus an operating position of the elevator brake device 20.
The brake housing 21 is fastened to the elevator car 2 via the support 9, wherein a guide rod 22 enables a lateral or horizontal displacement of the brake housing 21 with respect to the support 9 and the guide rail 6.
In normal operation, or in the first operating position BP1, the brake element 25 and the brake plate 30 are spaced from the guide rail 6, as in the FIGS. 9 and 10 shown. Fig. 9 shows a perspective rear view and Fig. 10 shows a plan view of the elevator brake device 20 in the first operating position BP1. The actuator 32 is fixed by the electro-magnet 36 and the locking roller 33 of the actuator 32 holds the brake housing 21 via an adjustable stop 21.1, against the force generated by the force storage 24 acting force F24, in the first operating position.
As an alternative to the adjustable stop 21.1, the position of the brake housing 21 can also be adjusted via the locking roller 33. For this purpose, the locking roller 33 may be fastened, for example with an eccentrically shaped axis on the locking lever 35. By rotating this axis of the locking roller 33 can thus the lateral position of the brake housing 21 in the support 9 and thus the position of the braking surface 7, and guide rail 6 are set exactly.

For the purpose of operating the elevator brake device, the electro-magnet 36 is turned off. The lock roller can therefore no longer provide blocking force, whereby the force accumulator 24 can press the brake housing 21 together with the brake member 25 against the braking surface 7 of the guide rail 6, as in the FIGS. 11 and 12 is shown. Again, it can be seen that, due to the delivery of the brake housing, a game between brake element 25 and braking surface 7 is repealed, while the game S1 + S1 'between the brake plate 30 and rail 6 is increased in the first operating step.

By a relative movement between the brake element 25 and the guide rail 6 of the control eccentric 25.1 of the brake element 25 is rotated and the brake shoe 25.2 is pressed on the control eccentric 25.1 to the braking surface 7 of the guide rail 6 (see Fig. 8 ), whereby a braking of the elevator car 2 takes place. Of course, in this case the brake plate 30 is pulled over the brake housing 21, whereby the guide rail 6 is clamped between the brake plate 30 and the brake shoe 25.2, and whereby simultaneously the brake housing 21 is pushed back toward the first operating position. The auxiliary weight 38 of the actuator 32 ensures that the actuator 32 follows this provision until the actuator 32 is again in its original position corresponding to normal operation. This has the advantage that a retaining mechanism of the actuator, for example a solenoid or a pawl, for fixing the actuator in this, the first operating position B1 corresponding reset position B3 only needs to be turned on, whereby the actuator 32 is reset without further return work. The holding mechanism can therefore be designed inexpensively. In the FIGS. 13 and 14 is the elevator brake device 20 shown in the braking position, wherein the actuator, as described, is again in its normal operation corresponding position B3.

The illustrated arrangements can be varied by the person skilled in the art. The brakes can be mounted above or below the car 2. It can also be used on a car 2 more Bremspaare. Of course, the braking device can also be used in an elevator installation with several cabins, in which case each of the cabins has at least one such braking device. If necessary, the braking device can also be mounted on the counterweight 3 or it can be mounted on a self-propelled cab.

Claims (14)

1. Lift braking device for braking a lift cage (2) on a brake surface (7), preferably on a brake surface (7) integrated in a guide rail (6), the lift braking device (20) comprising:

   - a brake housing (21),

   - a brake element (25), which is arranged in the brake housing (21) by means of a rotary bearing (28) to be rotatable and the brake element (25) has a curved shape (25.1, 26), which is so shaped with respect to the rotary bearing (28) that a radial spacing (R) from the rotary bearing (28) to the curve (25.1, 26) increases over a rotational angle (α),

   - a force store (24), which is constructed to press the brake element (25) by a force (F24) against the brake surface (7),

   - an actuator (32), which acts on the brake element (25) and which is constructed so as to urge, in a first operational setting (B1), the brake element (25) against the force of the force store (24) away from the brake surface (7) or to keep it at a spacing therefrom and to free, in a second operational setting (B2), pressing of the brake element (25) against the brake surface (7),

   characterised thereby, that the brake element (25) when it is pressed against the brake surface (7) is moved in such a manner by a relative movement between lift braking device (20) and brake surface (7) that the actuator (32) is moved back into a reset position (B3) corresponding with the first operational setting (B1).
2. Lift braking device according to claim 1, wherein the brake element (25) is incorporated in the brake housing (21) and the force store (24) and the actuator (32) act on the brake element (25) by way of the brake housing (21).
3. Lift braking device according to claim 2, wherein the brake housing (21) is mounted and held to be horizontally displaceable in a support (9) and that the actuator (32) is mounted in the support (9).
4. Lift braking device according to any one of claims 1 to 3, wherein the brake element (25) is mounted in the brake housing (21) by means of the rotary bearing (28) to be rotatable and the curved shape of the brake element (25) has a centre clamping region (26) which is eccentrically shaped with respect to the rotary bearing (28) so that the radial spacing (R) from the rotary bearing (28) to the clamping region (26) increases over a rotational angle (α).
5. Lift braking device according to claim 4, wherein the brake element (25) has a first braking region (27.1), which is connected with the centre clamping region (26), and the brake element (25) preferably has a second braking region (27.2), which is connected with an end of the centre clamping region (26) opposite the first braking region.
6. Lift braking device according to any one of claims 1 to 3, wherein the brake element (25) is mounted in the brake housing (21) by means of the rotary bearing (28) to be rotatable and has a control eccentric (25.1) with a curved shape, wherein the curved shape of the control eccentric (25.1) is eccentrically shaped with respect to the rotary bearing (28) so that a radial spacing (R) of the rotary bearing (28) from the curved shape of the control eccentric (25.1) increases over a rotational angle (α), wherein the brake shoe (25.2) can be pressed against the brake surface (7) by rotation of the control eccentric (25.1).
7. Lift braking device according to any one of claims 1 to 6, wherein the lift braking device (20) further comprises a brake plate (30) which is so arranged that a brake surface (7) or a corresponding guide rail (6) can be clamped between the brake element (25) and the brake plate (30).
8. Lift braking device according to claim 7, wherein the brake plate (30) is fastened in the brake housing (21) by means of a brake spring (31).
9. Lift braking device according to any one of claims 1 to 8, wherein the actuator (32) comprises a clamping electromagnet (36) with an armature plate (37), wherein in the first operational setting (B1) the armature plate (37) bears against the clamping electromagnet (36) and is electromagnetically held by this and the armature plate (37), when the actuator (37) is brought into the reset position (B3) corresponding with the first operational setting (B1) when the return movement takes place, is also brought into contact with the clamping electromagnet (37) in current-free state of the clamping electromagnet (36).
10. Lift braking device according to claim 9, wherein the actuator (32) is settable so as to enable setting of the first operational setting (B1).
11. Lift braking device according to any one of claims 1 to 10, wherein the actuator (32) includes an assisting weight (38), which holds an entrainer, preferably a blocking roller (33), in contact with the brake element (25) or the brake housing (21), or wherein the actuator (32) includes an assisting spring (39), which holds the entrainer, preferably the blocking roller (33), in contact with the brake element (25) or the brake housing (21).
12. Lift installation with a lift cage and with guide rails for guiding the lift cage (2) and with at least one lift braking device (20) according to any one of claims 1 to 11, wherein a brake surface (7) is integrated in the guide rail (6) and the lift braking device (20) acts when required on the brake surface (7) of the guide rail (6).
13. Lift installation according to claim 12, wherein the lift cage (2) is provided with two lift braking devices (20) and these lift braking devices (20) can act on two guide rails (6) arranged on opposite sides of the lift cage (2) and wherein these two lift braking devices (20) are coupled with a synchronisation rod (15).
14. Method of braking a lift cage (2) in a lift installation on a brake surface (7), preferably on a brake surface (7) integrated in a guide rail (6), by means of a lift braking device (20) according to any one of claims 1 to 10, comprising the steps of:

    - deactivating an actuator (32);

    - pressing a brake element (25) against a brake surface (7) by a force store (24);

    - moving the brake element (25) in such a manner by relative movement between brake element (25) and brake surface (7) that the brake element (25) constrainedly moves the actuator (32) back into a reset position (B3) corresponding with a first operational setting of the actuator (32).

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