Compact electromechanical actuator for the activation of lift emergency stop

Abstract

An electromechanical actuator comprising a support plate (23) and, arranged on same, a linear actuator (1) housed between a movable upper plate (16) and a fixed lower plate (17), and an accumulator spring (14). In addition, the linear actuator (1) comprises a suction coil (2) attached at the end thereof, as well as a movable reset catch plate (11) to which a magnetising plate (4) is attached and is therefore movable with the reset catch plate (11). The electromechanical actuator further comprises levers (10) for transmitting the actuation towards an interlocking roller (9.2) or towards two interlocking rollers (9.1) and (9.2), depending on whether it is a one-way or two-way safety gear. Lastly, the electromechanical actuator comprises a series of monitoring sensors. This enables much more force to be delivered, a simplification of the system, increased safety contact pressing distance, springs that work under compression and a silent stand-by mode.

Description

COMPACT ELECTROMECHANICAL ACTUATOR FOR ACTIVATING THE EMERGENCY STOP OF AN ELEVATOR Object of the invention

[0001] The object of the present invention, as stated in the title of the invention, is a compact electromechanical actuator with increased robustness and strength for an elevator parachute, forming a small-sized assembly for the emergency stop of an elevator and acting as an interface between an electronic overspeed detection system and an element responsible for stopping the elevator car in case of emergency.

[0002] The present invention is characterized by the special configuration and design of each of the parts of the mechanism so that the electromechanical positive safety drive can be arranged in a reduced volume, making it possible to mount it inside the frame rail, without it protruding from the rail, where the existing mechanisms are simplified, the robustness of the system is improved and the strength of the springs and the reset is increased.

[0003] The electromechanical actuator that is the subject of the invention is also characterized by the fact that it can be applied to both bidirectional and unidirectional parachutes.

[0004] Therefore, the present invention falls within the scope of elevators, and in particular within the safety means used to stop an elevator. Background of the invention

[0005] The prior art includes the electromechanical actuator disclosed in patent WO2023187321, which discloses a compact electromechanical activation system for an elevator safety gear, characterized in that it comprises: A fixed protective plate to which drive means are attached, based on a reset coil and a holding coil, and release means arranged in alignment. Movable wedging means activated by the drive means, and where these movable wedging means are arranged parallel to the drive means. One or two wedging rollers, depending on whether it is for a one-way safety gear system or a two-way safety gear system, respectively.

[0006] The existing actuators activate correctly, but the coil's force is just barely sufficient to overcome the force of the locking springs. This is due to the coil's physical limitations; it's impossible to supply more force for such a small size.

[0007] The aim is also to simplify the system, since the use of the cable and pulleys adds many parts to the activation of the existing actuators, complicating and lengthening the assembly considerably.

[0008] Another objective of this new activation method is to allow a greater pressing distance of the safety contact in case of interlocking, since in the activation of existing actuators it only has about 2 mm, and is very tight.

[0009] They are also looking to change the locking springs from tension to compression, which are much more consistent in the force they provide for production.

[0010] The system also introduces a silent standby mode, which allows the rollers to be gently lowered onto the guide in a controlled manner, thus de-energizing the suction cup and eliminating power consumption. With existing actuators, a standby mode is not very practical, as they need to remain off for extended periods (more than 8 hours) to compensate for the peak power consumption generated by the reset coil. Furthermore, their standby mode is not quiet, since the coil releases the rollers as if it were a normal operation, generating significant noise and marking the guides where the rollers make contact. With this actuator, the rollers can be brought close to the guide in a controlled manner and released once in contact, without causing wear or noise. Moreover, its low power consumption makes the energy savings worthwhile.

[0011] Therefore, the object of the present invention is to overcome the aforementioned drawbacks: Insufficient coil strength compared to the spring strength; Complexity of the system in both its assembly and operation due to the pulley and cable assembly; Reduced pulse distance of the safety contact in case of interlocking; Replacement of the traction interlock springs with others more suitable for a safety function; Non-silent standby mode where the coil releases the rollers, generating significant noise and marking the guides in the area where the rollers impact.

[0012] Furthermore, the present application also aims to develop an electromechanical actuator for elevator safety gears, as described below and essentially outlined in claim one. Description of the invention

[0013] The object of the present invention is set out in its essentials in the independent claim and the different embodiments are set out in the dependent claims.

[0014] The present invention relates to a compact electromechanical actuator with increased robustness and strength for the safety gear of an elevator that employs a linear actuator that is capable of supplying much more force than the coil used in the reset since said coil is very close to the force of the locking springs.

[0015] The electromechanical actuator of the invention comprises: A fixed support plate on which a linear reset actuator is mounted, floating between an upper and a lower plate, between which is an accumulator spring, the upper plate being vertically movable so that it moves closer to or further from the lower plate. A suction cup coil mounted integrally to the shaft of the linear actuator, and therefore movable, shifting between a suction cup magnetizing plate, which is integral with the reset pull plate, and the lower plate where the linear actuator is housed. Two actuation springs, which are compression springs, the spring for the upper roller and the spring for the lower roller. These springs are designed so that the Δx / Lo is as small as possible, so that the ratio between the maximum compression force and the minimum compression force is as close to 1 as possible.This is achieved by giving the springs a large initial length, resulting in high initial compression. This ensures that the force provided by the springs is as constant as possible and is not excessive at maximum compression.

[0016] Since the compression mechanisms for each spring are independent, it is simpler to regulate the wedging force required for each roller to move from resting on the roller end plate to resting on the guide. The upper spring only needs to overcome these frictions, and this is aided by the weight of the upper roller, cam, and connecting rod. The roller wedging system, whereby each roller is independently wedged, consists of two connecting rods with their respective cams attached to each actuating roller. The upper connecting rod is a third-class lever that, when subjected to a downward vertical force from the upper compression mechanism, pushes the upper roller downward. The lower connecting rod is a first-class lever that, when subjected to a downward vertical force from the lower compression mechanism, pushes the lower roller upward.A series of actuator monitoring sensors: A first monitoring sensor: Fixed to the top plate, it monitors that the accumulation spring is not compressed, meaning the reset is complete. It is pressed when the system is OK to operate. A second monitoring sensor: Fixed to the support plate, it monitors that the rod has fully retracted to complete the reset. It is pressed when the system is OK to operate. A third monitoring sensor, attached to the actuator rod, provides the signal to reverse the actuator's polarity to retract it once it has engaged the handle plate and reset the rollers. It is pressed when the suction cup touches the handle plate during reset; it must remain pressed for the system to be OK to operate.

[0017] In the event of a reset following a locking incident, the mechanism cannot be reset because the rollers are locked. Therefore, the actuator rod extends to the handle plate, engages it, but since it cannot move the plate, the actuator body moves closer to the handle plate while the rod retracts. All this travel and energy is stored in the accumulator spring. Once fully retracted, the system simply waits for the elevator car to move in the opposite direction of the locking incident. When the car moves, the accumulator spring releases the energy, forcing the rollers to retract and fully resetting the system.

[0018] In the case of using the compact electromechanical actuator for a one-way parachute, a single compression spring, a single connecting rod and a single roller are used, where the connecting rod is a first-class lever that, when receiving the downward force, pushes the lower roller upwards.

[0019] Thanks to the described features, the following advantages are achieved: Firstly, the use of a linear actuator allows for significantly greater force to be supplied, as in prior art systems the reset coil is insufficient to provide sufficient force for the locking springs. Secondly, the system is simplified by streamlining assembly, as cables and pulleys are not used to activate the actuators. Thirdly, the pulse distance of the safety contact in case of locking is increased. Another advantage is the use of compression locking springs, which are much more suitable for a safety function. Finally, a silent standby mode is implemented, allowing the rollers to be supported in the guide in a controlled manner to de-energize the suction cup and eliminate power consumption by the system.With the proposed actuator, the rollers can be brought close to the guide in a controlled manner and released once in contact without generating wear and noise, and low energy consumption is also achieved.

[0020] Unless otherwise stated, all technical and scientific terms used herein have the meanings commonly understood by a person skilled in the art to which this invention pertains. Similar or equivalent procedures and materials to those described herein may be used in the practice of this invention.

[0021] Throughout the description and claims, the word "comprises" and its variants are not intended to exclude other technical features, additives, components, or steps. For those skilled in the art, other objects, advantages, and features of the invention will become apparent partly from the description and partly from the practice of the invention. Explanation of the figures

[0022] To complement the description being made and in order to help a better understanding of the characteristics of the invention, according to a preferred example of its practical embodiment, a set of drawings is included as an integral part of said description, in which the following has been represented for illustrative and non-limiting purposes.

[0023] In Figure 1, we can observe the actuator that is the subject of the invention in a front view.

[0024] In Figure 2, we can observe the actuator in a side view.

[0025] Figure 3 shows a second side view of the actuator

[0026] Figure 4 shows a rear view of the actuator.

[0027] Figure 5 shows the actuator in a reset position

[0028] Figure 6 shows the actuator in a pre-wedging position.

[0029] Figure 7 shows a side view of the actuator for a one-way parachute

[0030] Figure 8 shows a first front view of the actuator for a one-way parachute

[0031] Figure 9 shows a second side view of the actuator for the one-way parachute. Preferred embodiment of the invention

[0032] In view of the figures, a preferred embodiment of the proposed invention is described below.

[0033] In Figures 1 to 4 we can observe that the compact electromechanical actuator of the invention comprises a support plate (23) where the different elements of the electromechanical actuator are fixed or linked, with a linear actuator (1) located on the top of said support plate (23) housed between a movable upper plate (16) and a fixed lower plate (17), with an accumulator spring (14) located between said plates.

[0034] The linear actuator (1) comprises a stem (24) which at its end has a suction cup coil (2) attached by means of a fixing element (3) to said suction cup coil (2).

[0035] On the other hand, the compact electromechanical actuator comprises a movable reset pull-plate (11) arranged on the support plate (23), with a magnetization plate (4) being linked to this reset pull-plate (11) and therefore movable with the reset pull-plate (11), using fixing means (18) for this purpose.

[0036] The compact electromechanical actuator comprises a lever (10) responsible for transmitting the actuation to a locking roller (9.2) (figures 7, 8 and 9) in the case of a one-way parachute or to locking rollers (9.1) and (9.2) in the case of a two-way parachute, this lever (10) being linked to the reset pull-plate (11) so that moving this reset pull-plate (11) produces the displacement of the lever (10).

[0037] The lever assembly (10) for actuation in the case of a bidirectional parachute comprises an upper connecting rod (19) and a lower connecting rod (20), both joined by a roller discriminator (21) and by a cylindrical guide (22) for the actuation spring of the lower roller and which joins the opposite ends of the upper connecting rod (19) and the lower connecting rod (20), the joining point of the upper connecting rod (19) and the upper end of the roller discriminator (21) being linked to the reset pull plate (11).

[0038] The roller discriminator (21) is responsible for moving one roller away from the guide when the other roller has fully locked in place.

[0039] Furthermore, the lever assembly comprises a first spring (12) for driving the upper roller (9.1) arranged between a fixed point (25) and the free end of the upper connecting rod (19), being responsible for transmitting the drive to the upper roller (9.1); it also comprises a second spring (13) for driving the lower roller (9.2), this second spring (13) being placed on the cylindrical guide (22) for the actuating spring of the lower roller (9.2) that joins the opposing ends of the upper connecting rod (19) and the lower connecting rod (20).

[0040] The upper connecting rod (19) is a third-class lever which, when subjected to a downward vertical force from the upper compression mechanism, pushes the upper roller (9.1) downwards. The lower connecting rod (20) is a first-class lever which, when subjected to a downward vertical force from the lower compression mechanism, pushes the lower roller (9.2) upwards.

[0041] For the correct operation of the electromechanical actuator in one possible embodiment, monitoring sensors are used, specifically: A first monitoring sensor (6), fixed to the movable upper plate (16), monitors that the accumulation spring (14) is not compressed, i.e., that the reset is complete; it is pressed when the system is ready to operate. A second monitoring sensor (5), fixed to an auxiliary plate which is in turn fixed to the support plate (23), monitors that the rod (24) has fully retracted to complete the reset. It is pressed when the system is ready to operate. A third monitoring sensor (7), attached to the actuator's rod (24), provides the signal to reverse the actuator's polarity to retract it once it has engaged the magnetizing plate (4) and, consequently, the reset pull plate (11), thus resetting the rollers.It is pressed when the suction cup coil (2) touches the magnetizing plate (4) which is attached to the reset pull plate (11), so that the system is OK to function it must remain pressed.

[0042] Additionally, the electromechanical actuator has a safety contact (8) that is only pressed when the rollers are fully wedged. It is pressed by the pull-tab plate (11), since when the rollers (9.1) (9.2) are resting on the guide, i.e., in the pre-wedge position, the pull-tab plate is not in its lowest position; it only reaches this position when one of the two rollers is fully wedged.

[0043] Figures 2, 3 and 4 show how the electromechanical actuator is linked to a mechanical parachute (15).

[0044] Since the pull plate (11) is "loose" when the rollers are pre-wedged, it will tend to fall under its own weight, and we only want it to fall to its lowest point when one of the two rollers is fully wedged. To prevent this, a small tension spring (26) is placed on top of the pull plate (11) which forces it to remain in the uppermost position until a roller is fully wedged and its connecting rod pulls it down, thus pressing the safety contact.

[0045] Figures 5 and 6 show the relative position adopted by the different elements of the lever system, with Figure 5 showing the reassembly position, while Figure 6 shows the pre-wedging position with the rollers supported on a guide (27).

[0046] As can be seen in the figures, the linear actuator assembly, the suction cup coil, the magnetizing plate, and the lever assembly (10) adopt a vertically aligned arrangement, which clearly reduces the volume required for its installation, making it more compact and with a reduced volume.

[0047] Figures 7, 8 and 9 show the electromechanical actuator slightly modified for application in a unidirectional parachute, without implying any modification of the principles of the object of the invention.

[0048] Therefore, the lever assembly in the case of a one-way parachute comprises a lower connecting rod (20) whose upper end is attached to the second spring (13) for driving the lower roller (9.2), where this second spring is placed on the cylindrical guide (22), while the lower end of the lower connecting rod (20) is attached to the cam that supports the lower roller (9.2), the upper end of the lower connecting rod (20) being linked to the reset pull plate (11).

[0049] Consequently, as can be seen in these figures, the upper roller (9.1), the upper cam, the upper connecting rod (19) with its pull pivot, the upper compression spring (12) and its guide system, as well as the discriminator (21), have been eliminated.

[0050] The lower connecting rod (20) is a first-class lever which, when receiving downward vertical force from the lower compression mechanism, pushes the lower roller (9.2) upward.

[0051] Having sufficiently described the nature of the present invention, as well as the manner of putting it into practice, it is stated that, within its essential nature, it may be put into practice in other forms of embodiment that differ in detail from the one indicated as an example, and which will also achieve the protection sought, provided that it does not alter, change or modify its fundamental principle.

Claims

- A compact electromechanical actuator with increased robustness and strength for an elevator safety gear, characterized in that it comprises a support plate (23) where the different elements of the electromechanical actuator are fixed or linked, comprising in the upper part of said support plate (23) a linear actuator (1) housed between a movable upper plate (16) and a fixed lower plate (17), with an accumulator spring (14) arranged between said plates; furthermore, the linear actuator (1) comprises a rod (24) which at its end has a suction cup coil (2) attached by means of a fixing element (3) to said suction cup coil (2); on the other hand, the compact electromechanical actuator comprises a movable reset pull plate (11) arranged on the support plate (23), with a magnetization plate (4) being linked to this reset pull plate (11) and therefore movable with the reset pull plate (11);The electromechanical actuator also comprises a lever (10) responsible for transmitting the actuation to a locking roller (9.2) or to two locking rollers (9.1) and (9.2), this lever (10) being linked to the reset pull-plate (11) so that displacement of this reset pull-plate (11) produces the displacement of the lever (10), and finally the electromechanical actuator comprises a series of monitoring sensors. - Compact electromechanical actuator with increased robustness and strength for an elevator safety gear according to claim 1 characterized in that the actuating lever (10) in the case of being used in a bidirectional safety gear comprises an upper connecting rod (19) and a lower connecting rod (20) both joined by a roller discriminator (21) and by a cylindrical guide (22) for the actuating spring of the lower roller that joins the opposing ends of the upper connecting rod (19) and the lower connecting rod (20), the point of union of the upper connecting rod (19) and the upper end of the roller discriminator (21) being linked with the reset pull-plate (11). - Compact electromechanical actuator with robustness and increased strength for a parachute of an elevator according to claim 2 characterized in that, furthermore, the lever assembly comprises a first spring (12) for driving the upper roller (9.1) arranged between a fixed point (25) and the free end of the upper connecting rod (19), being responsible for transmitting the drive to the upper roller (9.1); it also comprises a second spring (13) for driving the lower roller (9.2), this second spring (13) being placed on the cylindrical guide (22) that joins the opposing ends of the upper connecting rod (19) and the lower connecting rod (20). - A compact electromechanical actuator with increased robustness and strength for an elevator safety gear according to claim 1, characterized in that the actuating lever (10) when used in a one-way safety gear comprises a lower connecting rod (20) whose upper end is attached to the second spring (13) for actuating the lower roller (9.2), where this second spring is placed on the cylindrical guide (22), while the lower end of the lower connecting rod (20) is attached to the cam that supports the lower roller (9.2), the upper end of the upper connecting rod (19) being linked to the reset pull-plate (11). - A compact electromechanical actuator with increased robustness and strength for an elevator safety gear according to any of the preceding claims, characterized in that it comprises a series of monitoring sensors: A first monitoring sensor (6), fixedly placed on the movable upper plate (16), monitors that the accumulation spring (14) is not compressed, i.e., that the reset is complete; it is pressed when the system is ready to operate. A second monitoring sensor (5), fixed on the lower plate (17), monitors that the rod (24) has fully retracted to complete the reset; it is pressed when the system is ready to operate. A third monitoring sensor (7), attached to the rod (24) of the actuator, serves to give the signal to reverse the polarity of the actuator to retract it once it has engaged the magnetizing plate (4) and therefore the reset pull plate (11) and reset the rollers. - Compact electromechanical actuator with increased robustness and strength for a safety gear of an elevator according to any of the preceding claims, characterized in that it comprises a safety contact (8) which is only pressed when the rollers are fully wedged, being pressed by the pull-plate (11), since when the rollers (9.1) (9.2) are supported on the guide, i.e., in the pre-wedging position, the pull-plate is not in its lowest position, it only reaches this position when one of the two rollers is fully wedged.

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