HK1122781B - Method for preventing the collision of two lift cabins moving in one shaft and corresponding lift system - Google Patents

Description

The invention relates to a method for preventing the operation of two mobile lifting cabins in the same shaft of a lift system as defined in claim 1 and a lift system operated by this method as defined in claim 6.

Lifts with several lifting cabins in the same shaft, also known as multimobil lifts, usually have one drive and brake system per lifting cabin and are also equipped with a lift protection system to prevent collisions between the lifting cabins.

In addition to conventional electronically controlled elevator protection systems, such as WO 2004/043 842, European patent application EP-A-06 120 359 describes an elevator system with an elevator protection system with mechanically activated electro-mechanical switching mechanisms. The elevator protection system is simple in design and reliable in its operation. However, the disadvantage is that it only activates when a critical minimum distance is exceeded between two approaching elevators, without further braking criteria, such as the relative speed between the elevator cabins or the effective distance, being taken into account in each case.

The task of the invention is now to The manufacturer shall ensure that the vehicle is equipped with a means of transport that is capable of providing the service of the vehicle in a manner that is not in conformity with the requirements of this Regulation.

The emergency stop system should be designed to avoid any increase in the shaft cross-section.

The problem is solved For the process, by the features of claim 1; and for the lifting system, by the features of claim 6.

The advantages of embodiments and further training of the invention are described by the respective dependent claims.

The new elevator system has at least one upper and one lower lifting cabin, which can move up and down vertically in a common lift shaft of the elevator system, essentially independently of each other.

The upper cab has a first drive and brake system which includes a first brake (preferably a motor brake) The lower cab has a second drive and brake system which includes a second brake (preferably a motor brake) According to the invention, the first lift cab also has a first cab brake and the second lift cab has a second cab brake, the function of which is explained below.

In addition, the lift system shall have a lifting protection system to prevent collisions between the lifting cabs. The lifting protection system shall preferably include a first electro-mechanical control mechanism at the upper lifting cab and a second electro-mechanical control mechanism at the lower lifting cab, which may cause the upper lifting cab to be slowed by the first brake and/or the lower lifting cab to be slowed by the second brake. In particular, but not necessarily, the lifting cab and the lifting protection system may be trained in accordance with EP-A601209359.

The emergency stop system is designed so that, after the deceleration or braking is initiated by the brake stops, it continuously or repeatedly determines the momentary motion state of the two lifting cabs and, if necessary, by means of an associated cab brake, induces additional braking of one or both lifting cabs in motion, taking into account the motion state of the lifting cabs on the one hand and the braking criteria laid down on the other.

The state of motion of the lift cabins is, inter alia, and essentially, a function of their relative speed.

Braking criteria can in principle be set in advance, but the current state of movement of the lift cabs is taken into account.

Further details and advantages of the invention are described below by means of an example of an embodiment and with reference to the drawing. Fig. 1a multi-mobile elevator system according to the state of the art, in a highly simplified schematic representation;Fig. 2a ramp protection system and an emergency stop system on a multi-mobile elevator system, in a highly simplified schematic representation;Fig. 3a diagram to illustrate the procedure according to the invention;Fig. 4details of a particularly preferred example.

Fig. 1 shows a simple elevator system 10. Such elevators are known as multimobil elevators, as mentioned above. Elevator system 10 has an elevator shaft 11 in which an upper elevator cabin A1 and a lower elevator cabin A2 can move vertically. As long as a critical minimum distance d (a) is maintained between the two elevator cabins A1, A2, i.e. during normal operation where the momentary distance di is greater than the critical minimum distance d (a) 0, the elevator cabins A1, A2 can move independently in elevator shaft 11. Elevator system 10 has a drive and brake unit, with each A1 having its own drive and brake system.

The lifting system 10 shall also have a ramp protection system 20 The ramp protection system 20 shall comprise a first electro-mechanical control mechanism 21 located in a lower area of the upper lifting cab A1 and a second electro-mechanical control mechanism 22 located in an upper area of the lower lifting cab A2 The two control mechanisms 21, 22 shall be vertically superimposed.

The lift system 10's ramp protection system 20 shall preferably have a separate safety circuit for each lift cabin A1, A2 with several safety elements such as safety contacts and switches arranged in a serial circuit. The corresponding lift cabin A1 or A2 may only be moved if its safety circuit and therefore all safety contacts integrated in it are closed. The safety circuit shall be connected to the drive and brake unit of the lift system 10 or to the drive and brake systems of the lift cabins A1, A2 respectively in order to interrupt the operation of the corresponding lift cabin A1 and/or A2 if the safety circuit is opened and/or interrupted by the operation of the corresponding electromechanical switch/network 21 and 22 respectively.

The first actuator 21 has a load body 23 with a weight G suspended from an oblong flexible support 24 which is in turn attached to the lower part of the upper lifting cab A1.

The second switching mechanism 22 comprises a mechanical sensor in the form of a lever 28 (see Figure 2) acting on a contact switch 34.

In normal circumstances, i.e. when the distance di between the lifting cabs A1 and A2 is greater than the critical distance d (**), the lift 23 is freely suspended from the supporting element 24 which is held in tension and stretched by the weight G of the lift 23.

If the lifting boxes A1, A2 approach so close that their momentary distance is less than the critical distance d0, the drawbar 23 hits the lever 28 of the second electromechanical switch 22 and the pulling force exerted by the drawbar 23 on the supporting element 24 is reduced, and thus the pulling voltage in the supporting element 24 is largely reduced.

The significant reduction in the traction voltage in the supporting element 24 opens the safety circuit of the first drive and brake unit of the upper lifting cab A1. This triggers the braking of the upper lifting cab A1 by means of the first brake (e.g. designed as an engine brake). The impact of the load cell 23 on the lever 28 opens virtually simultaneously the safety circuit of the second drive and brake unit of the lower lifting cab A2. This triggers the braking of the lower lifting cab A2 by means of the second brake (e.g. designed as an engine brake).

However, the emergency stop system of the invention may also be used in elevator systems 10 whose updraft protection system is differently designed or whose brakes are differently activated and/or which are equipped with a safety bus system instead of the safety circuits mentioned.

According to the invention, the lift system 10 has, in addition to the ramp protection system 20, the emergency stop system, which, after the deceleration of one or both lift cabins A1, A2 by one or both brakes, allows the additional deceleration of the moving lift cabins A1 and/or A2.

The triggering of this additional delay shall be based on the current state of movement of lift cabs A1, A2 and on the emergency stop criteria.

The emergency stop system of the invention may have design elements of an approach protection system 20 and additional design elements, i.e. in this case the emergency stop system is at least partially integrated into the approach protection system 20.

In the case of a lifting system 10 according to the invention, the flexible supporting element 24 is not fixed directly or permanently at the bottom of the upper lifting cab A1 or a lever therein, but is attached to a roller 30 which is rotatable at the bottom of the upper lifting cab A1. This attachment is not shown in Figure 2.In the normal case, i.e. when the momentary distance di between the lifting cabins A1 and A2 is greater than the critical distance d0, the roll 30 is blocked against rotation by the tensile force exerted by the flexible load element 24 loaded with the weight G of the load body 23; that is, the roll 30 cannot be rotated by its internal energy storage 31 because of this blocking.the emergency stop system or its control system is activated. In this case, this is done by striking the load cell 23 on a sensor (e.g. lever 28 in conjunction with a switch 34) of the switch mechanism 22 of the lower lift cab A2. After striking the load cell 23, the traction force is released in the flexible support 24 by which the reel 30 was blocked. The reel 30 is released and now rotates under the roll-up torque supplied by its internal power storage 31 so that the flexible support 24 is unwrapped on the reel 30. The electrical release of the reel 30 occurs virtually simultaneously with the actuation of the mechanical control mechanisms and the electrical discharge of the A221, the lift's traction.A2 through their brakes. The reel 30 rotates after being released, and the part of the flexible supporting element 24 which corresponds essentially to the difference between the critical distance d0 and the momentary distance di of the lifting cabs A1, A2 is unwinded, but the lifting body 23 must not be pulled upwards.Other The rotation of the reel 30 allows the momentary state of motion of the lifting cabins A1, A2 to be determined from the momentary angular velocity ωi and the momentary distance di between the lifting cabins A1 and A2. Once the reel 30 rotates, their angular velocity ωi, which is a function of time, is recorded by an incrementator 32. From this angular velocity ωi, the momentary relative velocity vi (r) of the lifting cabins A1, A2 can then be determined.The driver shall be able to control the vehicle in the event of a failure of the service braking system. The following is an example of how this can be done. The following symbols shall be used: d0critical distance (maximum detection distance)dimensional distance of the lift cabins A1, A2ωimomentane angular velocity of the roller 30vi(rel)momentane relative velocity of the lift cabins A1, A2vimomentane velocity of one of the lift cabinsvi(A1)momentane velocity of the upper lift cabin A1vi(A2)momentane velocity of the lower lift cabin A2a(min)minimum achievable delay at emergency stopsmin)minimum stopping distance when only one lift cabin A1 or A2 is in motion (i.e. when virel) is vi) is vi) issstop(min) IIminimum stopping distance when both lifts are in motion A1 and A2 (d. Otherh.

The following assumptions or rules shall also apply:

In the context of this description, if both lift cabs A1 and A2 are running, they approach at the same speed vi(A1) = vi(A2), where vi(A1) and vi(A2) are absolute values.

If a contact switch 34 of the safety circuit of the lower lifting cab A2 is open and/or the instantaneous distance di between the lifting cabs A1 and A2 is less than the critical distance d0, each moving lifting cab A1, A2 shall be retarded by means of its brakes.

Criteria for emergency stop

The service braking system shall be so designed that the service braking system is capable of providing the service braking system with the service braking system.

Criterion A: If a lift cab A1 or A2 is running and the instantaneous distance di between the cabs A1 and A2 is less than or equal to the corresponding minimum stopping distance sstop (min) I, the cab brake of the moving lift cab A1 or A2 shall apply braking.

Criterion B: If both lift cabs are running and the momentary distance di between lift cabs A1 and A2 is less than or equal to the corresponding minimum stopping distance sstop(min) II, braking shall be initiated by cab brakes of both lift cabs A1 and A2.

For the purpose of determining the state of motion and comparing it with the emergency stop criteria, the following shall be recorded or calculated: Other

Durch Messung:	Ist eine Kabine nicht in Fahrt?
Durch Berechnungen:

Figure 3 shows a diagram illustrating the operation of the entire braking system using both the brake and the cab brakes.

Field F1 shows measured and available values, namely

vi ((rel); di; vi ((1); vi ((2); position of contact 34; once these values are available, question Q1 is used to determine whether contact 34 is open and/or di<d0.

If the answer to Question Q1 is no, then obviously no braking is required, either by the brake stops or by the cab brakes.

If the answer to question Q1 is yes, the brake application shall be performed according to box F2, i.e. the emergency stop system shall not be induced to apply additional braking by the cabin brakes.

Then, with question Q2, it is determined whether both elevator cabins are in motion.

If question Q2 is answered with no N, then only one of the elevator cabins is in motion, so question Q3 is asked.

Question Q3 determines whether di is equal to or even less than sstop (min) I.

If the answer to Question Q3 is yes, J, then if the minimum stopping distance for this case is reached or less, an additional braking is applied by the corresponding cab brake for an emergency stop according to box F3.

If question Q3 is answered no, then another question, Q4, is asked.

Question Q4 asks whether the relative speed of the elevator cabins is zero.

If the answer to question Q4 is yes, this can only mean that both cabs are no longer in motion, because according to box F2 the brakes are engaged and according to box N, only a lift cab A1 or A2 is in motion. According to box F4, no further braking by cab brakes is required, as the braking effect of the brake is obviously sufficient.

If Question Q4 is answered in the negative, Question Q2 is asked again.

If the answer to question Q2 is yes, then both A1 and A2 are in motion and question Q5 is then asked.

Question Q5 clarifies whether di is equal to or even less than stop (min) II.

If Question Q5 is answered with no N, Question Q4 is asked for further clarification, i.e. Question Q4 clarifies whether the relative speed vi (r) of the lift cabs A1, A2 is zero. If this is the case, according to box F4 no additional braking with cab brakes is necessary.

However, if the answer to question Q5 is yes, then according to box F3 an additional braking is performed by the cabin brakes for an emergency stop.

If more than two lifting cabs are operating in the same lift shaft 11, a corresponding emergency stop system may also be installed between these lifting cabs.

Fig. 4 shows a particularly favourable embodiment of a major part of the emergency stop system 21 The reel 30 on which the load-bearing device 24 winds up when not subjected to the weight of the attached load 23 is shown. On the same shaft 42 as reel 30 is a union drive 31 which is also called an energy storage. An incremental generator 32 is installed on a coupling 40. The connection is made via an adapter 41.

Claims (9)

1. Method of preventing collision of two lift cages (A1, A2), which move substantially independently of one another in a common shaft (11), of a lift installation (10), wherein a collision protection system (20) triggers a retardation of each moved lift cage (A1, A2) by a stopping brake when an effective distance (di) between the lift cages (A1, A2) falls below a critical minimum distance (dk), characterised in that after triggering of the stopping brake an emergency stop system (21)

   - ascertains, by means of a control system, instantaneous movement states of the cages (A1, A2) on collision course and

   - triggers, by means of cage brakes associated with the lift cages (A1, A2), an additional retardation of one or both lift cages (A1, A2) when the movement state thereof fulfils definable emergency stop criteria.
2. Method according to claim 1, characterised in that the emergency stop criteria are ascertained with consideration of the instantaneous movement states of the lift cages (A1, A2).
3. Method according to claim 1 or 2, characterised in that the control system for ascertaining the instantaneous movement states of the lift cages (A1, A2) repeatedly

   - detects the instantaneous relative speed (vi(rel)) of the lift cages (A1, A2) and

   - with consideration of the instantaneous relative speed (vi(rel))

   - ascertains instantaneous effective distance (di) between the lift cages (A1, A2),

   - ascertains as emergency stop criteria an instantaneous minimum emergency stopping distance (s_stop(min)I, s_stop(min)II) and

   - ascertains whether the instantaneous effective distance (di) is smaller than or equal to the instantaneous minimum stopping distance (s_stop(min)I, s_stop(min)II) so as to then trigger the cage brake of each moved lift cage (a1, a2).
4. Method according to claim 3, characterised in that the control system detects the relative speed (vi(rel)) of the lift cages (A1. A2) in that a rotational frequency (ωi) of a roller (30), which is fastened to the upper lift cage (A1) and on which is wound up a flexible support element (24) having an unwound length substantially corresponding with the critical minimum distance (d0), when on falling below of the minimum distance (d0) a weighting body (23) impinges on the lower lift cage (A2) and in that case releases the roller (30) for rotation.
5. Method according to claim 4, characterised in that

   - a tension force (G) exerted by the weighting body (23) on the support element (24) secures the roller (30) against rotation thereof before the weighting body (23) impinges on the lower lift cage (A2) and

   - the roller (30) is released for rotation when the tension force (G) exerted by the weighting body (23) on the support element (24) ceases when the weighting body (23) impinges on the lower lift cage (A2).
6. Lift installation (10) with at least one upper lift cage (A1) and at least one lower lift cage (A2), which in normal operation of the lift installation (10) are vertically movable independently of one another in a common shaft (11), wherein

   - the upper lift cage (A1) has a first driving and braking system with a first stopping brake and

   - the lower lift cage (2) has a second driving and braking system with a second stopping brake and wherein

   - a collision protection system (20) is provided, by which triggering of the stopping brakes can be initiated when an instantaneous distance (di) between the lift cages (A1, A2) is less than a critical minimum distance (d0), characterised in that an emergency stop system (21) is provided

   - with a control system by which the instantaneous movement state of the lift cages (A1, A2) is detectable in the case of a further falling below of the minimum distance (d0) after triggering of the stopping brakes and emergency stop criteria are ascertainable and

   - with a first cage brake for the upper lift cage (A1) and a second cage brake for the lower lift cage (A2), wherein one or both cage brakes can be triggered when the emergency stop criteria are fulfilled.
7. Lift system (10) according to claim 6, characterised in that the control system for detecting the instantaneous movement state of the lift cages (A1, A2) after triggering of the holding brakes comprises:

   - means for determining the instantaneous effective distance (di) between the lift cages (a1, a2),

   - means for determining the relative speed (bi(rel)) of the lift cages (A1, A2),

   - means for determining the minimum stopping distance of the lift cages (A1, A2) with consideration of the relative speed of the lift cages (A1, A2),

   - means for comparing the instantaneous minimum stopping distance with the instantaneous effective distance and

   - means for triggering the cage brake of each moved lift cage (A1, A2) when the effective distance is less than or equal to the minimum stopping distance.
8. Lift system (10) according to claim 7, characterised in that the means for determining the relative speed and the effective distance of the lift cages (A1, A2) comprise

   - a flexible support element (24)

   - with a first end which is fixed to a roller (30) and can be wound up on this roller (30) and

   - with a second end to which a weighting body (23) is fastened,

   wherein the length of the flexible support element together with the weighting body (23) corresponds with the critical minimum distance, and wherein

   - the roller (30)

   - is rotatably fastened to the upper lift cage (A1),

   - comprises an internal energy store (31) by which a winding force can be exerted on the roller (30) by which the roller can be set into rotation,

   - is coupled with means (32) for detecting its rotational frequency,

   - is blocked against rotation by a tension force, which is exerted by the weighting body (23) on the support element (24), when the distance between the lift cages (A1, A2) is greater than the critical minimum distance and

   - rotates under the winding force when the weighting body (23) has impinged on the lower lift cage (A2),

   - and with means for calculating the relative speed and the effective distance from the rotational frequency of the roller (30).
9. Lift system (10) according to claim 6, characterised in that the collision protection system (20) comprises:

   - a first safety circuit with a first electromechanical switching mechanism (21), by which the stopping brake of the first lift cage (A1) can be triggered, at the first lift cage (A1) and

   - a second safety circuit with a second electromechanical switching mechanism (22), by which the stopping brake of the second lift cage (A2) can be triggered, at the second lift cage (A2),

   wherein the first switching mechanism (21)

   - comprises the support element and the weighting body (23),

   - is held under the weight of the weighting body (23) in a travel setting and by which

   - the first holding brake can be activated after impinging of the weighting body (23), and

   wherein the second switching mechanism (22)

   - is arranged below the weighting body (23),

   - is held in a travel setting before the impinging of the latter and by which

   - the second holding brake is activatable after impinging of the weighting body (23).