WO2019197703A1

WO2019197703A1 - Elevator with a rail brake arrangement

Info

Publication number: WO2019197703A1
Application number: PCT/FI2018/050255
Authority: WO
Inventors: Matti RÄSÄNEN; Markku Haapaniemi; Otto Lanz; Lasse Nyman; Mikko VILJANEN; Tarvo Viita-Aho; Kai Guo
Original assignee: Kone Corporation
Priority date: 2018-04-09
Filing date: 2018-04-09
Publication date: 2019-10-17

Abstract

The invention relates to an elevator with a safety brake arrangement, which elevator comprises at least an elevator operating system, a control system (9), a door control arrangement (2b), a safety system, an elevator car (2) arranged to run in the elevator shaft (1) along guide rails (3), and a safety brake unit (8) which comprises a rail gripper (15) which is controlled by a first control arrangement (2a). The safety brake unit (8) comprises a rail brake arrangement (20) which is controlled by a control arrangement, other than the first control arrangement (2a).

Description

ELEVATOR WITH A RAIL BRAKE ARRANGEMENT

The present invention relates to an elevator with a rail brake arrangement as defined in the preamble of claim 1.

One problem in elevator arrangements according to prior art is a bouncing effect that occurs during a loading and un loading of an elevator car. Particularly, the bouncing ef fect occurs in elevators having great hoisting heights, for instance in high rise elevators. The number and dimensioning of elevator suspension ropes are determined with two varia bles, namely safety factor and elastic elongation of the ropes. Because, in prior art arrangements, the elevator car cannot be locked to guide rails during the loading and un loading of the elevator car the bouncing effect must have been prevented by adding a number of suspension ropes . That reduces the elastic elongation of the ropes and at the same time the bouncing effect. But, it is in most cases unneces sary in the safety factor's point of view. The disadvantage is that the additional ropes cause at least more weight, costs and need for maintenance.

Another problem in elevator arrangements according to prior art relates to safety conditions during the loading and un loading of the elevator car when the elevator car doors are open. In case an unintentional movement takes place, the el evator car moves a short travel before the safety brake sys tem stops the movement. That may cause damages to people who are just entering to the elevator car or exiting from the elevator car when the unintentional movement takes place.

Yet another problem in elevator arrangements according to prior art relates to the safety during service, maintenance and inspection of the elevator. Various tasks, such as in- spections, adjustment works, maintenance or repairs are of ten performed in the elevator shaft. In that case the safety of the persons working in the elevator shaft has always to be secured. If the height of the top clearance of the eleva tor shaft is shallow, a sufficient safety space, which pre vents injuries occurring for persons working in the elevator shaft, cannot always be guaranteed without special proce dures .

In the case mentioned above an unintentional movement of the elevator car must be prevented in some other way than by the regular operating brakes of the elevator. It is known in the prior art that this kind of prevention can be done by lock ing the elevator car and/or the counterweight into their po sitions on the guide rail, for instance by means of a safety gear, a latch or wedges. However, this often requires that the working persons must separately go to the elevator shaft and perform the locking. That makes safety preparation tasks awkward, laborious and time-consuming.

Another known solution is to fix a rope clamp to the hoist ing roping, by means of which rope clamp the hoisting roping is bound fast to e.g. the overhead beam of the shaft. This is also, however, an awkward and time-consuming solution and requires special tools.

Yet another solution according to prior art for achieving an adequate safety space in the upper part of an elevator shaft is to use one or more turnable buffers or movable pillars that are disposed below the counterweight. The buffer is lifted upright before going onto the roof of the elevator car to work. The length of the buffer is such that the move ment of the counterweight, and at the same time the movement of the elevator car, stops before the elevator car rises too high with respect to the ceiling of the elevator shaft. One problem, among others, in this solution is, however, that the shaft space might have been dimensioned so precisely that there is no proper space in the bottom part of the ele vator shaft for a turnable buffer. Another problem is that the aforementioned buffer ensuring the top safety space is in the bottom part of the elevator shaft, i.e. right at the other end of the elevator shaft. In that case installing the buffer into the safe position takes extra time and it may also happen that for this reason the person in charge does not remember to go down to the bottom of the elevator shaft to turn them into the safe position.

The same applies when achieving an adequate safety space in the lower part of an elevator shaft. In that case one or more turnable buffers or movable pillars are disposed below the elevator car. Most of the difficulties mentioned above apply also in this case.

One object of the present invention is to eliminate draw backs of prior art technology and to achieve an elevator with a rail brake arrangement, wherein the bouncing effect disturbing loading and unloading the elevator car is mini mized, and wherein the safety arrangement is operationally extremely reliable, easy and fast to use and surely guaran tees a required safety space in the elevator shaft regard less of a possible carelessness or ignorance of the persons performing the tasks in the elevator shaft, and wherein the unintentional movement of the elevator car during loading and unloading can be automatically prevented. The elevator, according to the invention, with a rail brake arrangement is characterized by what is disclosed in the characterization part of claim 1. Other embodiments of the invention are characterized by what is disclosed in the other claims. The inventive content of the application can also be defined differently than in the claims presented below. The in ventive content may also consist of several separate inven- tions, especially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. In this case, some of the attributes contained in the claims below may be superfluous from the point of view of separate inventive concepts. Likewise, the different details present ed in connection with each embodiment can also be applied in other embodiments. In addition, it can be stated that at least some of the subordinate claims can, in at least some situations, be deemed to be inventive in their own right.

An aspect of the invention is to provide an elevator with a rail brake arrangement, which elevator comprises at least an elevator operating system, a control system, a door control arrangement, a safety system, an elevator car arranged to run in the elevator shaft along guide rails, and a safety brake unit which comprises a rail gripper which is con trolled by a first control arrangement. Advantageously the safety brake unit comprises a rail brake arrangement which is controlled by a control arrangement, other than the first control arrangement.

One advantage of the invention is that the invention enables an elevator where the bouncing effect during loading and un loading the elevator car is minimized. Another advantage of the solution according to the invention is that a number of suspension ropes can be optimized to as close as possible the safety factor. Yet another advantage is that an unin tended movement of the elevator car can be effectively, re liably and safely prevented when the door of the elevator car is open. Means or operations for preventing unintended movement of the elevator car could also be called UCM func tion. Yet another advantage is that the solution is very easy and quick to use, and does require neither awkward working in the elevator shaft nor preliminary procedures at the top end or bottom end of the elevator shaft before the service, maintenance or inspection work, and the solution gives a secure and safe protection for the service, mainte nance or inspection work. Yet one advantage is that the so lution of the invention reduces wear of critical safety de vices during maintenance operations, and it also improves maintenance efficiency by reducing manually activated parts. In addition, the invention reduces possibility of the eleva tor car becoming stuck due to worn guide rails or safety gears and.

Yet another advantage of the invention is that invention en ables a safe way of providing an elevator that can have a shallow pit and headroom. Yet a further advantage is that the integration of the rail brakes to the frame of the safe ty gear units takes sense because braking forces are di rected to the same structures as in a gripping situation. Yet a further advantage is that the solution is inexpensive, simple to implement and does not require much space. Yet a further advantage is also that the solution of the invention makes the structures of the elevator lighter and makes func tions of the elevator simpler.

In the following, the invention will be described in detail by the aid of example embodiments by referring to the at tached simplified and diagrammatic drawings, wherein

Fig. 1 presents in a simplified and diagrammatic side view a part of the building where the back wall of the elevator shaft is removed, and an elevator in the elevator shaft, in which elevator the rail brake arrangement according to the invention can be used,

Fig . 2 presents in a simplified and diagrammatic side view the elevator according to Fig. 1 in two different positions: in the uppermost position and in the lowermost position, showing the sizes of the head- room and pit of the elevator,

Fig . 3 presents in a simplified and diagrammatic oblique top view one type of integrated safety brake unit according to the invention,

Fig . 4 presents in a simplified and diagrammatic top view the integrated safety brake unit according to Fig. 3, with an elevator guide rail, and partially cross-sectioned,

Fig . 5 presents in a simplified and diagrammatic front view the lower part of the integrated safety brake unit according to Fig. 3,

Fig . 6 presents in a simplified and diagrammatic front view a rail brake block according to the invention in its recess in the frame of the safety brake unit according to the invention,

Fig . 7 presents in a simplified and diagrammatic front view an empty recess for the rail brake block ac cording to the invention, and

Fig . presents in a simplified and diagrammatic front view a rail brake block according to the invention.

Figure 1 presents in a simplified and diagrammatic side view a part of the building where the back wall of the elevator shaft 1 is removed, and an elevator in the elevator shaft 1, in which elevator the rail brake arrangement according to the invention can be used. The building has four floors 10 served by the elevator. The elevator is a so-called Machine-Room-Less (MRL ) elevator where the elevator machinery 5 with its operating brakes 6 and traction sheave is in the elevator shaft 1 or in an ap- propriate space adjacent to the elevator shaft 1, and in the upper area of the elevator shaft, advantageously just below the ceiling of the elevator shaft 1. In addition the eleva tor comprises among other things an elevator car 2 that is arranged to run up and down in the elevator shaft 1 along guide rails 3 guided by guide shoes 7, and a counterweight 4 or balance weight that is also arranged to run up and down in the elevator shaft 1 along its guide rails which are not presented in figure 1 for the sake of clarity. The elevator car 2 and the counterweight 4 are connected to each other with elevator ropes or hoisting ropes that also are not pre sented in figure 1 for the sake of clarity. The cross sec tion of the hoisting ropes can be round or as a flat rectan gle. The elevator car 2 is also equipped with safety gear arrangement comprising preferably two integrated safety brake units 8 and a synchronizing structure to synchronize the functions of the safety brake units 8. The safety gear arrangement is arranged to stop the movement of the elevator car 2 and to facilitate an easy and safe locking of the ele vator car 2 into the guide rails 3 when needed. The safety gear arrangement used in this embodiment is a bi-directional system, but it can also be a unidirectional system.

In addition, the elevator comprises at least an operating system, an electrical system, a control system with a con- trol arrangement 9, a safety system with a control arrange ment 9a, a door control arrangement 2b, and a variety of sensor arrangements. Preferably the safety system comprises an inspection and/or maintenance mode. Figure 2 presents in a simplified and diagrammatic side view the elevator according to Fig. 1 in two different positions: in the uppermost position and in the lowermost position, showing the heights of the headroom 11 and pit 12 of the el evator. In the uppermost position the elevator car 2 and the counterweight or balance weight 4 are presented in a solid line, and in the lowermost position the elevator car 2 and the counterweight 4 are presented in a dot-and-dash line. The fast, safe and easy locking of the elevator car 2 to the guide rails 3 makes it possible to improve the efficiency of maintenance operations, and in that way safety in elevators with a shallow headroom 11 and/or pit 12 can be easily in creased .

Figures 3-8 present in simplified and diagrammatic views one type of an integrated safety brake unit 8 and a rail brake block according to the invention. For the sake of clari ty, the safety brake unit 8 is presented alone without any connection elements or fastening elements.

Figure 3 presents the integrated safety brake unit 8 in an oblique top view, whereas figure 4 presents the integrated safety brake unit 8 according to figure 3 in a simplified and diagrammatic top view, with an elevator guide rail 3, and partially cross sectioned, and figure 5 presents in a simplified and diagrammatic front view the lower part of the integrated safety brake unit 8 according to figure 3, a first cover plate 19 removed and the second cover plate 18 in its normal position. Figure 6 presents in a simplified and diagrammatic front view a rail brake block 28 according to the invention in its recess 35 in the frame 13 of the safety brake unit 8, figure 7 presents in a simplified and diagrammatic front view an empty recess 35 for the rail brake block 28, and figure 8 presents in a simplified and diagrammatic front view a rail brake block 28 according to the invention.

As mentioned above the safety brake arrangement according to the invention comprises the safety brake unit 8 that has a substantially solid frame 13, preferably of a rectangular shape, with a longitudinal slot 14 for the guiding flange 3a of the guide rail 3. A rail gripper 15 comprising a first gripping element 16, with one or more gripping surfaces 16a, and a second gripping element 17, is placed in the frame 13 of the safety brake unit 8 substantially in a known way, so that the first gripping element 16 is on the first side of the slot 14 and the second gripping element 17 is on the second side of the slot 14. Placed in that way the first gripping element 16 is on the first side of the guiding flange 3a, and a second gripping element 17 is on the second side of the guiding flange 3a.

The second gripping element 17 is a known force element, such as a roller that is arranged to move along a guided path in a known way to cause the rail gripper 15 to grip to the guiding flange 3a of the guide rail 3 in order to stop the movement of the elevator car 2 when needed. The rail gripper 15 is controlled by a first control arrangement 2a of the elevator in a known way. Preferably the first control arrangement 2a is a speed governor.

In addition to the rail gripper 15 the safety brake unit 8 comprises a rail brake arrangement 20 that also is placed in the frame 13 of the safety brake unit 8, making the safety brake unit 8 a multifunctional device. The rail brake ar rangement 20 comprises an actuator unit 20a and a braking unit 20b operatively coupled to the actuator unit 20a. The actuator unit 20a is fastened onto a side of the frame 13 of the safety brake unit 8 with a fastening element 21. The actuator unit 20a comprises a power unit 22, an actuator 24 having a vertically moving motion bar 25 that is driven by the power unit 22, and a motion lever 26 connected at its first end to the free end of the motion bar 25 and at its second end to the braking unit 20b. The power unit 22 is preferably an electric motor. The power unit 22 is connect ed, for example, through a cable 23 to one or more control arrangements 2b, 9, 9a of the elevator, which control ar rangements 2b, 9, 9a are fitted to control the safety brake unit 8, more precisely, the rail brake arrangement 20 of the safety brake unit 8.

The speed governor 2a being the first control arrangement for controlling the safety brake unit 8, the door control arrangement 2b is the second control arrangement for con trolling the safety brake unit 8, the control arrangement 9 of the elevator control system is the third control arrange ment, and the control arrangement 9a for the elevator safety system is the fourth control arrangement for controlling the safety brake unit 8. Preferably the fourth control arrange ment 9a is applied, for example when using the inspection or maintenance mode of the elevator.

Thus, the safety brake unit 8 can be controlled at least with four different control arrangements; the speed governor 2a, the door control arrangement 2b, control arrangement 9 of the elevator control system, and the control arrangement 9a for the elevator safety system.

The braking unit 20b comprises two brake blocks 28, actuat ing shafts 39 and 39a, to move the brake blocks 28, a syn chronizing arrangement 42 to synchronize the movements of the brake blocks 28, and return springs 41 to return the brake blocks 28 to their unoperated state. The brake blocks 28 are placed in their own recesses 35 in the frame 13, at each side of the slot 14, substantially opposite to each other .

The two brake blocks 28 are essentially similar to each oth er comprising a body 29 connected to a front plate 30 that can be the same material with the body 29 and integrated with it, or a separate part that is fastened to the body 29. The front plate 30 is equipped with one or more brake pads 31 to press against the guiding flange 3a of the guide rail 3 when the braking unit 20b is activated. The body 29 com prises guiding surfaces 32 to co-operate with the counter guiding surfaces 36 of the recess 35 of the frame 13 in or der to keep the movement of the brake blocks 28 linear. In addition, the body 29 comprises first counter surfaces 33 for the first ends of return springs 41 whose second ends lean against second counter surfaces 37 of the recess 35. Further, the body 29 comprises an opening 34 for the actuat ing shaft 39, 39a that is arranged to go through the opening 34 so that the eccentric cam 40 of the actuating shaft 39, 39a is inside the opening 34. The first ends of the actuat ing shafts 39, 39a are pivoted to the cover plates 18 and 19, and the second ends of the actuating shafts 39, 39a are pivoted to openings 38 in the frame 13.

The second end of the motion lever 26 is connected at its second end to the first actuating shaft 39a to rotate the first actuating shaft 39a, and the synchronizing arrangement 42 having two toothed lever elements 43, 44 transmits the rotation of the first actuating shaft 39a to the second ac tuating shaft 39 so that both the actuating shafts 39, 39a rotate in the same rate. When the actuating shafts 39, 39a are rotated towards the first direction the eccentric cams 40 move both the brake blocks 28 towards the guiding flange 3a of the guide rail 3 to create a braking force against the guiding flange 3a of the guide rail 3, and when the actuat ing shafts 39, 39a are rotated towards the second direction the eccentric cams 40 release both the brake blocks 28 and the return springs 41 return the brake blocks 28 to their unoperated position.

The solution of the invention uses an electrical control system to activate the rail brake arrangement 20 to stop the elevator car 2 during maintenance operations with the help of a positioning system of the elevator. After the system notices that the elevator car 2 has exceeded a predefined level in the shaft 1, the operating brakes 6 activate to stop the elevator car 2 and the rail brake arrangement 20 is activated after the elevator car 2 has stopped. Moving the elevator car 2 is allowed only in the opposite direction. If for some reason, both the operating brakes 6 and rail brake arrangement 20 fail at the same time, the bidirectional safety brake units 8 can be activated with a mechanical ac tivation onto guide rails 3.

Advantageously the rail brake arrangement 20 is used as a loading and unloading brake. In that case, when the elevator car is on a floor 10 and the door of the elevator car 2 be gins to open the actuator unit 20a receives an order to ac tivate the braking unit 20b in order to lock the elevator car 2 to the guide rails 3 with the brake blocks 28. When the door is closing the actuator unit 20a receives an order to deactivate the braking unit 20b in order to unlock the elevator car 2 from the guide rails 3 by loosening the brake blocks 28 from the guiding flange 3a of the guide rail 3. Advantageously the locking and unlocking is controlled by limits switches integrated to the actuator unit 20a.

The rail brake arrangement 20 is preferably also used during inspection and maintenance tasks. In those cases, the eleva tor car 2 is driven to a wanted height and by using an ap propriate application or button the braking unit 20b is giv en an order to lock the elevator car 2 to the guide rails 3 with the brake blocks 28 and to unlock the elevator car 2 from the guide rails 3 by loosening the brake blocks 28 from the guiding flange 3a of the guide rail 3.

In addition, the elevator is preferably equipped with an au tomatic UCM function, which means preventing an uncontrolled movement of the elevator car 2. For the automatic UCM func tion, the rail brake arrangement 20 is arranged to lock the elevator car 2 automatically to the guide rails 3 with the brake blocks 28 when the door of the elevator car 2 is open.

It is obvious to the person skilled in the art that the in vention is not restricted to the examples described above but that it may be varied within the scope of the claims presented below. Thus, for instance the structures and com ponents of the rail brake arrangement may differ from what is presented above.

Claims

1. Elevator with a rail brake arrangement, which elevator comprises at least an elevator operating system, a control system (9), a door control arrangement (2b), a safety sys tem, an elevator car (2) arranged to run in the elevator shaft (1) along guide rails (3), and a safety brake unit (8) which comprises a rail gripper (15) which is controlled by a first control arrangement (2a), characterized in that the safety brake unit (8) comprises a rail brake arrangement (20) which is controlled by a control arrangement, other than the first control arrangement (2a) .

2. Elevator according to claim 1, characterized in that the safety brake unit (8) comprises a frame (13) that is common to both the rail gripper (15) and to the rail brake arrange ment ( 20 ) .

3. Elevator according to claim 1 or 2, characterized in that the rail brake arrangement (20) is controlled by a control arrangement (9) of the elevator control system.

4. Elevator according to claim 1, 2 or 3, characterized in that the rail brake arrangement (20) is controlled by a door control arrangement (2b) of the elevator.

5. Elevator according to claim any of claims above, characterized in that the rail brake arrangement (20) is con trolled by a control arrangement (9a) of the elevator safety system.

6. Elevator according to any of claims above, characterized in that the rail brake arrangement (20) comprises an actua- tor unit (20a) and a braking unit (20b) usably connected to the actuator unit (20a) .

7. Elevator according to claim 6, characterized in that the actuator unit (20a) comprises a power unit (22) that is con nected to one or more control arrangements (2b, 9, 9a) of the elevator .

8. Elevator according to claim 6 or 7, characterized in that the actuator unit (20a) is a spindle motor.

9. Elevator according to claim 6, 7 or 8, characterized in that the braking unit (20b) of the rail brake arrangement (20) comprises at least two brake blocks (28) and a synchro nizing arrangement (42) to synchronize the movements of the brake blocks (28) .

10. Use of the safety brake unit (8) of the elevator accord ing to claim 1 as a loading and unloading brake by locking the elevator car (2) with the brake blocks (28) of the rail brake arrangement (20) to the guide rails (3) for the period of time when the elevator car (2) is landed at a floor (10) and the door of the elevator car (2) is open.

11. Use of the safety brake unit (8) of the elevator accord ing to claim 1 as an additional safety securing by locking the elevator car (2) with the brake blocks (28) of the rail brake arrangement (20) to the guide rails (3) for the period of time when inspection and maintenance tasks are performed.

12. Use of the safety brake unit (8) of the elevator accord ing to claim 1 to prevent unintentional movements of the el evator car (2) by locking the elevator car (2) with the brake blocks (28) of the rail brake arrangement (20) to the guide rails 3.