EP1209117A1

EP1209117A1 - Elevator car parachute system with up and down actuation

Info

Publication number: EP1209117A1
Application number: EP00927252A
Authority: EP
Inventors: Javier Inchaurza San Pedro
Original assignee: Selcom Aragon SA
Current assignee: Selcom Aragon SA
Priority date: 1999-05-28
Filing date: 2000-05-12
Publication date: 2002-05-29
Anticipated expiration: 2020-05-12
Also published as: WO2000073193A1; ES2156730A1; EP1209117B1; DE60004067D1; WO2000073193A8; ES2156730B1

Abstract

This has been conceived in order to permit instantaneous and/or progressive braking actuation of the cabin, having for the actuation in descent a roller (16) secured at the end of a rotating articulated arm (23), with the former sliding along an inclined ramp for instantaneous action, while for progressive actuation the said roller (16) acts on smooth and inclined leaf springs (9, 10). For actuation in ascent, the block or box has a descent ramp for the roller (16) and an elastic brake shoe (18); existing two inclined planes for instantaneous wedging with angles of inclination of opposite sign, these planes being made in the box in order to allow continual displacement of the roller (16).

The roller (16) has a knurled central part of larger diameter than the end pins, these latter being where the rolling support is established.

Description

OBJECT OF THE INVENTION

This invention, as stated in the statement of this description, refers to an anti-crash system for elevator cabins, with ascending and descending actuation, with which notable advantages are contributed to the operation of electrical traction elevators.
In elevators, the elevator cabin is suspended from steel cables which, because of the resulting adherence in the groove of the traction pulley and depending on its direction of rotation, causes the cabin to be able to move in the ascending and descending direction.
This operation is governed by existing regulations, in compliance with which, they are compulsory in all countries of the European Community.
These regulations are safety standards relating to elevators in order to protect people and property against the different risks of accidents that may occur as a result of the operation of elevators, both for users and for maintenance and surveillance personnel.
In order to prevent excess speed in the descent of the cabin, either due to breakage of the suspension bodies or to any other cause, the said standard provides for the use of:
a) Speed limiter.
b) Anti-crash system actuated by the speed limiter.
The operation sequence is as follows.
The speed limiter is synchronized with the motion of the cabin and is regulated so that it is electrically triggered, either in the ascent or in the descent, in order to force the machine to stop by means of an electrical anti-crash system before the cabin reaches the speed at which the regulator is triggered, which must be a minimum of 115% of the cabin rated speed and a maximum of a value that depends on that rated speed.
When this triggering occurs, the power supply to the drive machine is cut off, the mechanical brake for that machine is actuated and the cabin is halted, either going up or coming down.
In the descending motion, if in spite of the above action, either due to a fault in the braking system of the machine or due to a breakage of the suspension bodies, the cabin continues to descend and increases its speed, then the speed limiter is mechanically blocked and it causes the anti-crash system for the cabin to actuate by grasping the elevator guides, thus causing the elevator to stop.
Depending on the conditions of use, the anti-crash system can be of the following types:

Progressive type if the rated speed of the cabin is greater than 1.00 m/sec.
Instantaneous type with damping effect if the speed does not exceed 1.00 m/sec.
Instantaneous type if the speed is no more than 0.63 m/sec.

The progressive type and instantaneous type of anti-crash systems are the ones most used, bearing in mind the speed of application.

BACKGROUND OF THE INVENTION

With the current regulations, the cabin has to be equipped with an anti-crash system that can only act in the downward direction, capable of halting the cabin under full load at the regulator triggering speed, even in the case of breakage of the suspension bodies, which it does by grasping the guides for the cabin and capable of keeping it retained in them.
It is expressly prohibited for an anti-crash system to actuate in the ascending direction.
Consequently, anti-crash system found on the market are designed in accordance with these provisions and they act only in the descending direction.
Nevertheless, it can happen that a cabin, at the moment of ascending, and lightly loaded at that moment so that the total weight of the cabin is less than the weight of the counterweight, fails to stop because the machine brake has not acted due to some anomaly.
Since most elevating machines are reversible, in this situation the counterweight will accelerate the cabin in the upward direction and as the only mechanical element capable of halting the ascending cabin - the machine brake - is out of action, an uncontrolled motion of the cabin occurs until the counterweight collides with the bottom of the elevator shaft, producing a corresponding impact on the cabin.
In July 1999 European directive 95/16/CE will be coming into force, which in turn involves the coming into force of a new standardized norm EN/81.
This norm considers action against the chance event quoted above:
Protective measures against excess cabin speed when ascending, with certain articles being complied with.
In order to achieve this aim, action can be taken on:
a) The cabin
b) The counterweight
c) The cables
d) The traction pulley
For cases in which the solution is to act on the cabin, the norm has modified the content of some articles in order to expressly allow that an anti-crash system can be used when the cabin is rising in accordance with regulations as a protective means against excess cabin speed.
In cases of actuation on the cabin, in other words, basing ourselves on the anti-crash systems, there are two possible alternatives:

Use two anti-crash systems working in tandem: one acts on the descending motion, as has so far been done, and the other acts on the ascending motion.
Use an anti-crash system that works in both directions equally.

The anti-crash systems used can be one of two types:
a) instantaneous action and b) progressive action.
So far, considering just the downward actuation, instantaneous anti-crash systems are mostly designed with an inclined plane on which a roller moves in contact with the guide and its subsequent wedging causes the cabin to halt, as we will see later in relation to the figures.
In the case of progressive actuation anti-crash systems, the basic designs are based on inclined ramps, elastic elements combined with rollers or wedges that move in combination with the ramp producing the gradual halting of the cabin, or a design based on rotating cams which, combined with elastic elements, produce the gradual halting of the cabin by means of the corresponding rotation.
In the case of the second alternative, in other words, rotating cam anti-crash system, solutions are known within the family of progressive anti-crash systems based on a cam that rotates in one direction or another, depending on whether the actuation is in the ascending or descending direction, but not so for those based on the inclined plane, neither for instantaneous action nor for progressive action.

DESCRIPTION OF THE INVENTION

In general lines, the anti-crash system for elevator cabins, with ascending and descending actuation, which constitutes the object of the invention, proposes a solution to the problems stated above concerning ascending and descending anti-crash systems and both instantaneous action and progressive action.
In both cases, the operation principles for actuation when descending are going to be the same as those currently being used, in other words, rollers with inclined ramp for instantaneous action and roller with inclined smooth leaf springs for progressive action.
For actuation when ascending, a descent ramp for the roller is added to the same block along with an elastic brake shoe for the upward motion of the cabin, and an oscillating arm for actuation of the roller in order to overcome its displacement on the two inclined planes with angles of inclination of opposite sign.
The instantaneous actuation anti-crash system, in other words, with instantaneous wedging, provides for the actuation of the roller on the knurled zone in order to wedge against the guide, as an instantaneous action anti-crash system in descent and transfer of the roller on the groove of the box in order to permit it to roll and act progressively when ascending in order to guarantee the permitted deceleration and subsequent unblocking of the system.
In the anti-crash system for progressive action with progressive wedging, independent regulation of the braking forces in the upwards and downwards direction is achieved in order to comply with the deceleration permitted requirements according to the relevant standard for elevators:

between 0.2 g and g m/sec² for the descending motion of the cabin and
a maximum of g m/sec² for the ascending motion of the cabin,

In this latter system, a continual groove is considered, without any transition zone, so that the roller does not lose its position and rolls along its entire trajectory of displacement and work, both in the leaf springs area for wedging in descend and in the recess of the block for wedging in ascent.
In both systems of actuation, provision is made for the location of the lower mobile shoe in a pack of disc springs offset above the fixed braking zone corresponding to actuation in descent in order to supply a controlled and progressive braking force in the actuation in the ascent.
Provision is also made for a rotating oscillating arm permitting displacement of the roller up and down on both faces of the inclined plane.
In order to keep the roller in its rest position, which corresponds to the intersection of the two inclined planes of opposite angle of actuation of the roller, there exist two pistons, adjustable in terms of their position, which act on the arms of a support integral to the rotating axis shaft of the oscillating arm or articulated arm.
When an external action tends to pull the roller from its rest position, the resistance of one of the two pistons, depending on the sense of rotation of the shaft, will have to be overcome.
In order to facilitate an understanding of the characteristics of the invention and forming an integral part of this description, attached are some sheets of plans in whose figures the following are represented by way of illustration and non-restrictive way:

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1, 2 and 3. Are respective views in front elevation, side elevation and plane views of a conventional frame of an instantaneous wedging cabin.
Figures 4 and 5. Are respective views in elevation and side elevation of the friction support assembly and wedging box for that conventional cabin frame in the above figures.
Figure 6. Shows the wedging system with conventional progressive actuation.
Figures 7 and 8. Are respective views in plane and elevation of the instantaneous wedging system, in descent and progressive in ascent, in accordance with the invention.
Figures 9 and 10. Are respective view in plane and elevation of the progressive wedging system in ascent and descent, in accordance with the invention.
Figure 11. Is a cross-section view in longitudinal elevation of one of the two pistons aided by re-stressed springs, stabilizers for the rest position of the wedging roller.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION

Referring to the numbering system adopted in the figures and more specifically in relation to figures 1 to 6 in which the current state of the technique is shown, we can see that the elevator cabin is contained within the frame referenced in general with number 1. In the lower part of the frame 1 and on each side of it are the braking blocks or anti-crash systems 2, with one of them being connected, in this case via a draw tube 3, to the actuation cable of the speed limiter.
Since both anti-crash system blocks 2 are synchronized together, in this solution by means of a square tube 4, the actuation of one of the blocks 2 implies the simultaneous actuation of the other, due to which the anti-crash system assembly acts on both guides at the same time.
When the speed limiter is triggered with the cabin descending, the cable is immobilized, causing the draw bar 3 to rise, which causes the actuator arm 5 of the roller 6 to rotate in the opposite direction.
As can be seen on a larger scale in figure 4, this actuator arm 5, by means of its integral shaft housed inside the roller 6 that was at rest being supported between the shaft 7 and the inclined plane of the box 8 of the anti-crash system, causes the said roller 6 to rise, becoming more and more enclosed until contact is made with the guide and it becomes wedged in it and causing the cabin to stop in its descent.
These elements and modes of operation mentioned in the above paragraph correspond to a wedging of the cabin in descent by instantaneous actuation of the roller.
Wedging by progressive actuation is similar to the above, being different only in the way in which the braking force is transmitted where, as shown in figure 6, the inclined ramp is formed by two leaf springs 9 and 10, and a roller 11 that is moved in the same way as in the instantaneous case but which rolls on a groove in the leaf spring 10, until it acts as a stop in the brass piece 12.
In this upward motion of the roller a displacement of the anti-crash system block is produced thanks to a transverse displacement system of the assembly, but this is not relevant to the topic that we are concerned with, in such a way that the brake shoe 13 is enclosed against the guide. For the roller 11 to be able to reach the stop of the shoe 13, the pair of leaf springs 5 and 6 have been bent in such a way that they are pressing the roller 11 against the guide, causing the guide to rub against the brake shoe 13 which produces the braking force due to friction against the guide.
By altering the position of the support pins 14 of the leaf springs and of the bending to which they are subject, the braking force can be regulated according to the load to be halted, so that the application of the force can be gradual and controlled in such a way that the resulting deceleration is within the prescribed limits.
Making special reference now to figures 7 and 8 we can see the device used according to the invention in order to obtain a dual wedging system: instantaneous in descent and progressive in ascent. It comprises the following main elements:
The block or box 15 which is characterized in that it has a recess with one vertical face parallel to the guide 17 and close to it, and the other formed by an inclined plane in the upper part, as has been done so far, for the wedging of the cabin during its descending motion, and in the lower part with the angle in the opposite direction, so that the roller 16 can act against the guide 17 in the upwards motion of the cabin.
This lower inclined plane has a longitudinal slot machined into it along the entire descending trajectory of the roller 16 in order to allow it to roll, as we will see later on.
In the lower part of the vertical face parallel to the guide 17, a housing has been made where the shoe 18, the pack of ring washers 19, and the sliding shaft 20 are all housed.
The roller 16 has a staggered outline, with two diameters, unlike the rollers for instantaneous anti-crash systems for ascent only, which are cylindrical.
The central zone, of larger diameter, is knurled and is the one that works against the guide 17. The two side pins are smooth cylinders, of equal diameter, and which are going to permit the roller 16 to roll on the box 15 when it is acting in the rising motion of the cabin.
In order to make the roller 16 circulate on the two inclined planes 21 and 22 of the box 15, with opposite gradients, a rotating articulated arm 23 is provided with its center of rotation in the shaft 24, composed of the following pieces:

Conductor arm 25 integral to the shaft 24 which produces the rotating motion upwards or downwards, of the entire assembly.
Actuator arm 26 of the wedging roller 16, provided with a slot 29 for being able to slide axially with respect to the conductor arm by means of having sliding fastenings by means of the pieces 27 and 28. Piece 27 is materialized by means of a shaft with lateral guides that is introduced into the opened-up hole or slot 29 of the actuator arm 26. In the piece 28 a rectangular opening or window has been made matching the shape shown by the tail or rear part 30 of the actuator arm 26, of constant cross-section.
The compression spring 31, guided in the rear part 30 of the actual actuator arm 26 and located between the rear face of the piece 28 and a stop 32 fixed to the arm, so that the roller 16 of the anti-crash system is at all times positioned against the face of the block or box 15.

For the actuation of the draw tube 3, this same piece 28 is exploited in order to make the connection.
This assembly means that, when the wedging is actuated, whether upwards or downwards, the runner arm 26 is displaced with respect to the piece 27 to the same degree as the distance of the roller 16 to the rotating shaft for the assembly changes in its displacement, resting on the corresponding inclined plane of the box 15.
In order to control the position of the articulated arm assembly in its central rest position, a rear plate 33 has been provided integral to the rotating shaft 24, which in general has a "T" shape.
Integral to the support plate 34 of the system, though with possibilities of being adjusted, two pistons 35 are placed underneath the wings of the "T" shape of the rear plate 33, with these two pistons housing in their interior separate springs under compression with an initial preload, rolled around the shafts of the pistons and acting on those wings.
As the position of the shafts in their piston is predetermined, the position of the pistons in the system assembly is adjusted in such a way that the actuation force of them on the rear plate 33 is zero in the rest position of the roller 16 of the anti-crash system.
This enables the system to remain stable in normal operation because if, due to the inertia of the motion, the roller 16 tends to move, the corresponding side of the arm or wing of the "T" shape would have to act against one of the pistons 35 and overcome the force of the corresponding preloaded spring while the other piston would not act in this motion since, on its side, the arm of the "T" is displaced away from it.
Obviously, when a real actuation of the anti-crash system takes place, the force exercised by the speed limiter via the draw tube has to be sufficient to make the articulated arm rotate and also overcome the corresponding force of the spring of the piston.
The operation of the assembly would be as follows:
During normal operation, the assembly composed of the articulated arm 23 and the roller 16 is kept in position in the central part of the box 15, due to the plate 33 is resting on the heads of the pistons 35.
If, during a descending motion of the cabin, the speed becomes excessive, the draw bar acts upwards on the arm 25 which rotates pulling on the arm 26 which is longitudinally displaced on its two guides 27, 28, overcoming the force of the spring 31. The roller 16 is displaced upwards rotating on its knurled face resting on the inclined face of the block 15 until it makes contact with the guide 17.
In that moment, the roller 16, becomes blocked and is wedged between the box 15 and the guide 17 producing the instantaneous halting of the cabin.
In order to unblock the system, so that it becomes operative again, it is sufficient to act from the outside to produce an ascending motion of the cabin, as stated in the regulations, so that the roller 16 becomes unwedged and the system returns to its rest position.
If, during the ascending motion of the cabin, its speed becomes too fast, the draw bar 3 acts downwards on the arm 5 with the same sequence of motion as in the above case, permitting the arm to be able to rotate downwards.
Consequently, the roller 16 is displaced towards the lower part of the box 15 rotating on the side pins, since the central knurled part remains in the air within the groove made in the block, until it comes up against the grooved brass stop 36.
In this position, the roller 16, resting on the plane 22 of the box 15 and the lower stop 36, pushes the guide 17 against the elastic brake shoe 18.
During the entire time of the braking action, the roller 16 is rolling due to the meshing action of its knurled part against the guide and the support for the smooth gudgeons against the stop and the plane of the grooved block.
The lower stop 36 is mounted on a shaft screwed into the box 15 in such a way that the height of its position can be adjusted so that the roller always acts essentially centered with respect to the elastic brake shoe 18.
As can be seen in figures 7 and 8, the brake shoe 18 is projecting slightly with respect to the vertical face of the box 15. When the roller 16 in the guided descent motion makes contact with the guide 17, it pushes the guide against the brake shoe 18, which, due to the strength of the spring pack 19, gives rise to a gradual braking force. This force reaches a maximum at the moment the shoe reaches the same level as the rest of the vertical face of the box 15, since it cannot be compressed any further due to the fact that the guide 17 is now in simultaneous contact with the elastic shoe 18 and the rigid face of the box 15.
By adjusting the compression stroke of the spring pack 19 it is possible to adjust the braking force in ascent, depending on the mass to be halted.
During the braking action in ascent, the roller 16 continues to rotate on its pins and there is no embedding action of the roller that could prevent its subsequent unblocking.
To unblock the system, in such a way that it again becomes operative, it is sufficient to act from the outside and loosen the suspension cables, making the traction pulley rotate towards the descending direction so that the weight of the cabin itself unwedges the roller and the system returns to the rest position, as we had stated earlier.
This system of stopping the cabin when ascending is of progressive action type in order that the deceleration when rising can be less than or equal to the action of gravity and in order to allow for the later unblocking of the system. The reason for this is that, as it is not possible to act directly on the cabin from the outside, the weight of the cabin itself may not be sufficient for unblocking it in the event that a system was designed with roller wedging similar to that produced in the actuation during the descending motion. This is due to the fact that the roller 16 would remain embedded in the guide 17 and the box 15 and the weight of the cabin itself would not be sufficient for unblocking it.
Referring now to figures 9 and 10, in this example of embodiment of the invention we can see the progressive wedging system comprising the following main elements:
The block or box 15 which, for acting in descent, is characterized in that it has the same elements as those mentioned in the classical anti-crash system, namely, the pair of leaf springs 9 and 10 which, acting on the roller 16, pushes the guide 17 against the brake shoe 18 giving rise to the stopping of the cabin exactly the same as in the method initially described.
For acting on the ascending motion of the cabin the same elements as those described in the case of the instantaneous anti-crash system have been added to the system, that is:

Brake shoe 18 fitted on a disc spring pack 19 which provides the braking force, adjustable according to the load to detain at the moment of the cabin ascends.
Grooved inclined plane of opposite angle to the leaf springs 9 and 10 permitting the roller 16 to descend rolling on the box 15 until it makes contact with the guide 17 and continues rolling on the box 15 during its actuation.
Oscillating arm 23, composed of the conductor arm 25 and the actuator 26, which permits the roller 16 to be positioned, either upwards or downwards of the box 15, so that it is displaced by rolling on the two inclined planes of that box.
Piston stopping system of piston stops 35 for positioning of the oscillating arm 23 in such a way that the assembly remains in the rest position during the normal operation of the elevator.

Due to the fact that, in both the ascent and the descent, the actuation of the anti-crash system has to be progressive, the roller 16 has to be rotating during its actuation, because of which at all times, both when it is acting on the leaf springs (9, 10) during the actuation in descent, and when it is acting on the box 15 during the actuation in ascent, it must rest on the cylindrical gudgeons co-lateral to its knurled central zone and it must keep that knurled central part in the air throughout its possible travel.
For this, the box 15 has been machined in such a way that the groove of the leaf springs and of the box form a continuous whole so that this condition can be guaranteed throughout the entire trajectory of the roller 16.
Otherwise, the manner of operation and unblocking is similar to that described for instantaneous wedging.
In figure 11, one of the pistons 35 can be seen whose head 37 acts on the corresponding wing of the "T" shaped rear plate 33 integral to the rotating shaft 24, as we had indicated earlier.

Claims

ANTI-CRASH SYSTEM FOR ELEVATOR CABINS, WITH ASCENDING AND DESCENDING ACTUATION, both for instantaneous actuation and for progressive actuation, having for actuation in descent a roller (16) which slides along an inclined ramp for instantaneous action and a roller (16) with smooth inclined leaf springs (9, 10) for progressive action, characterized in that it includes for the ascending action on the same block a descent ramp for the roller (16), an elastic brake shoe (18) for the upward motion of the cabin and a rotating articulated arm (23) for actuation of the roller (16) in order to allow its continual displacement on the two inclined planes with angles of inclination of opposite sign, provided in the block (15) for instantaneous wedging, with the opposite part of the recess of the block (15) having a vertical face parallel and close to the guide (17), with the lower inclined plane (22) being the carrier of a central longitudinal slot along its entire trajectory in order to permit the roller (16) to roll resting on its end pins and to permit its central knurled part to pass through that machined slot, with this central part being the one that acts on the guide (17).
ANTI-CRASH SYSTEM FOR ELEVATOR CABINS, WITH ASCENDING AND DESCENDING ACTUATION, according to claim 1, characterized in that the rotating articulated arm (23) rotates around an arm (24) emerging from the support plate (34) integral to the block (15) and is composed of a conductor arm (25) radially integral to the shaft (24) and of an actuator arm (26) carrying the roller (16) which is axially displaceable with respect to the above since it incorporates a slot (29) in which a piece (27) moves integral to the conductor arm (25), as well as its extreme tail like end in which is guided in a diametrical window of another piece (28) integral to the same conductor arm (25), with a spring (31) that keeps both arms (25, 26) in retracted position and the roller (16) adopting a neutral position against the angular face of the block (15).
ANTI-CRASH SYSTEM FOR ELEVATOR CABINS, WITH ASCENDING AND DESCENDING ACTUATION, according to claim 2, characterized in that the shaft (24) is rotating and integral to a "T" shaped rear plate (33) and whose arms are aided by separate pistons (35) provided with re-stressed springs stabilizing this rest position.
ANTI-CRASH SYSTEM FOR ELEVATOR CABINS, WITH ASCENDING AND DESCENDING ACTUATION, according to claim 1, characterized in that the progressive wedging action is achieved for the actuation in descent by means of the roller (16) of the oscillating arm (21) being forced by the inclined pair of leaf springs (9, 10) to be against the conventional brake shoe (13), while for actuation in ascent of the cabin the lower part of the box includes the shoe (18) aided by the adjustable action disc springs (19), as well as the inclined grooved ramp of the lower part of the box with opposite angle to the leaf springs (9, 10), permitting the roller (16) to descend rolling until it makes contact with the guide (17), with provision being made so that both the upper leaf springs (9, 10) and the lower inclined plane (22) of the box (15) include machining so that the roller (16) can at all times roll on the end of the cylindrical gudgeons and keep free the knurled central part.