ELEVATOR SYSTEM

FIELD OF THE INVENTION

The present invention relates to elevator systems. In particular, the invention relates to determination of the degree of opening of a landing door.

PRIOR ART

In the installation of elevators, existing as well as new elevator shafts may not always have an exactly equal width at all height levels of the shaft. When this is the case, an elevator car moving in the eleva- tor shaft will come at one level closer to a wall of the elevator shaft than at another level .

The width of the elevator shaft is a limiting factor regarding the aperture of the elevator door. Therefore, if the ^' elevator shaft is not of uniform width, the width dimension of a door zone that is narrower than other door zones means for the elevator manufacturer a necessity to use a narrower door.

For the design of the sizes of doors for elevator shafts, there are several different dimensioning guidelines. One of the dimensioning rules is as expressed by the following formula: LL*1,5 + 30, where LL is door width. If the door width is 700 mm, then the width of the elevator shaft should be 1080 mm at the levels of the doors .

Fig. 1 illustrates a situation by way of example in the case of a three-floor building. Using a suitable meas- uring method, it has been established that the elevator shaft width is 1100 mm at level A, 1080 mm at level B and 1060 mm at level C. If the dimensioning rule pre-

sented above as an example is applied, then for a door width of 650 mm the elevator shaft should have a width of at least 1005 mm. Similarly, for a door width of 700 mm the elevator shaft should have a width of 1080 mm. In the case of the example presented in Fig. 1, the elevator could only be provided with a door having a width of 650 mm, because a door width of 700 mm would be too large at level C.

US2006/0070821 discloses a solution where the movement of elevator doors is controlled on the basis of opening limits stored in control system memory. According to this specification, the door opening limits are taught to the system and saved to system memory. A problem in- herent in this solution is that the arrangement is complex and requires the use of a servo with a feedback property.

A problem encountered in prior-art solutions is how to enable the door size to be maximized regardless of variation in elevator shaft width. A further problem is how to enable maximum opening of the door at different floors .

BRIEF DESCRIPTION OF THE INVENTION

The system of the invention is characterized by what is disclosed in the characterizing part of claim 1. The method of the invention is characterized by what is disclosed in the characterizing part of claim 6. Other embodiments of the invention are characterized by what is disclosed in the other claims. Inventive embodiments are also presented in the description part and drawings of the present application. The inventive content dis- closed in the application can also be defined in other ways than is done in the claims below. The inventive content may also consist of several separate inventions,

especially if the invention is considered in the light of explicit or implicit sub-tasks or with respect to advantages or sets 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. The features of different embodiments of the invention can be applied in connection with other embodiments within the scope of the basic inventive concept .

The object of the present invention is to disclose a solution according to which an elevator operated in an elevator shaft of non-uniform width can be provided with a door of a width as large as possible. The basic principle of the solution is that at certain floors (at the levels of which the elevator shaft is narrower than elsewhere) the landing door is opened to a lesser extent than at other floors, thus enabling a door aperture as large as possible.

According to an aspect of the invention, an elevator system is proposed which comprises at least one elevator and a control system controlling the elevator. The elevator system is characterized in that the landing door comprises detector elements for the determination of a maximum extent of opening of the landing door; the elevator car comprises means for sensing the detector elements moving with the landing door when the landing door is being opened, and said means have been arranged to send to the control system controlling the door a signal for stopping the opening movement of the landing door; and the control system has been arranged to stop the opening of the landing door in response to the signal received from said means .

In an embodiment of the invention, said means comprise a limit switch and the detector elements comprise a mechanical bar which meets the limit switch when the door is opening.

In another embodiment of the invention, said means comprise a light cell and the detector elements comprise a light source.

In another embodiment of the invention, said means comprise a light cell and a light source, and the detector elements comprise a reflector.

In another embodiment of the invention, said means com- prise means for detecting a magnet, and the detector elements comprise a magnet.

The invention also relates to a method for opening an elevator landing door. The method is characterized in that, when the landing door is being opened, detector elements moving with the landing door are sensed by- means attached to the elevator car, and the opening movement of the landing door is stopped in response to the sensing of- the detector elements.

The invention makes it possible to adjust the maximum opening of an elevator door in narrow elevator shafts or in elevator shafts of non-uniform width. To maximize the door aperture at floors where the door area is nar- rower, limited door opening is applied.

BRIEF DESCRIPTION OF THE FIGURES

The attached figures illustrate embodiments of the in- vention and, in conjunction with the description of the embodiments of the invention, help explain the principles of the invention. In the attached drawings:

Fig. 1 is a diagram representing an elevator shaft;

Fig. 2a is a diagram representing a situation where an elevator landing door is in the closed position according to an embodiment of the invention; and

Fig. 2b is a diagram representing a situation where an elevator landing door is completely open according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following, the present invention will be de- scribed in detail by referring to embodiments of the invention and to the attached figures.

Fig. 2a presents a diagrammatic illustration of a situation where an elevator landing door is in the closed position according to an embodiment of the invention. Fig. 2b correspondingly presents a diagrammatic illustration of a situation where the elevator landing door is in a fully open position according to an embodiment of the invention. It is obvious to a per- son skilled in the art that the elevator car, the elevator door solution and the elevator system in general comprise many different elements and devices that are not shown in Figs. 2a and 2b. Figs. 2a and 2b only show elements essential to the invention.

In the example presented in Fig. 2a, the landing door 20 is provided with a mechanical bar 22 attached to it at a position which can be adjusted if necessary. When the bar 22 meets a limit switch 26, the limit switch 26 sends to the control system 28 (to the door control) data indicating that the landing door 20 is fully open and the opening movement of the door can be stopped. As

the bar is attached to the landing door and is adjustable, an opening limit can be defined separately for each floor on the basis of the width of the elevator shaft. If the elevator shaft is wide enough to permit the door to be opened completely, then no bar is needed at all. In this case, the maximum door opening width is limited by the normal limit switches or other corresponding limit sensors of the so-called door operator opening/closing the door.

Figs. 2a and 2b present an example of how the invention is implemented using a mechanical limit switch. As the bar 26 can not necessarily be held in a transverse orientation relative to the door leaf except when the ele- vator is opening the doors at a landing where a bar 26 is provided, an arrangement for turning the bar in an opening situation is required.

The turning can be implemented by many different meth- ods. In one method, the door coupler engaging the car door exerts a pressure on a plate attached to the lower end of an axle rod so that the bar placed at the other end of the axle rod is turned. In another method, when the landing door begins to open, the bar is turned to the appropriate position by friction or a corresponding mechanism and restored to a rest position when the door begins to close.

As for placement of the limit switch 26 on the elevator car, there are various alternatives. The limit switch 26 may be placed on the top of the elevator car, under the elevator car, in the mechanism of the elevator car door, on the threshold of the elevator car or at any other position suited for the purpose.

In another embodiment, the landing door is provided with a light-emitting diode whose placement is adjust-

able. Placed on the top of the elevator car is a light cell which, upon detecting the light ray from the light-emitting diode, sends door-open limit data to the control system (door control) . In an embodiment, both a light-emitting diode and a light cell are placed on the top of the elevator car, and the landing door is provided with a mirror which directs the ray from the light-emitting diode to the light cell when the door is at its extreme open position.

In another embodiment, a magnet is mounted at a suitable point on the landing door, and a sensor is mounted on the top of the elevator car. The sensor detects the magnet and sends door-open limit data to the control system when the landing door has been opened to its extreme position.

In another embodiment of the invention, the mechanical and magnetic solutions are combined. If the sensor in the magnet solution has a short sensing distance, then a bar is used as in the mechanical solution. This bar is magnetic, and thus the magnet is brought closer to the sensor.

An essential factor in the solution proposed by the invention is that all the electric equipment needed for the solution is installed on the elevator car while the landings are only provided with an adjustable mechanism that requires no electricity. The solution proposed by the invention is simple, because the adjustment can be easily carried out separately for each floor by means of the components mounted on the landing doors.

Although the invention has been described above with reference to preferred embodiments, different changes and variations are possible within the sphere of protection defined by the claims.