Traditionally, the landing doors of an elevator are mounted by attaching both the upper and lower ends of the door frame directly to the building. In other words, the door sill is fixed to the lower edge of the door opening while the overhead supporter is fixed separately to the upper edge of the door opening. A drawback with such a structure is above all the diffi- culty of installation and structural complexity. Both the door sill and the overhead supporter must be in- stalled separately according to accurate measurements.

Previously known are also solutions in which the land- ing door is fixed to a secondary structure attached to the building. For instance, in elevator shafts of steel construction, landing doors have been mounted using an H-shaped steel frame generally attached by its lower end to the floor slab and by its upper end to the slab supporting the floor above. Such a frame requires a great deal of design work and is expensive to manufacture and difficult to install.

In general, mounting the landing door is a problematic and difficult task because it is difficult to find suitable attachment points for both the door sill and the overhead supporter and because the shaft dimen- sions may vary considerably from floor to floor. Nev- ertheless, the door openings must be precisely aligned along the same straight line. Moreover, the landing door structures cannot be rigidly connected to each other between different floors because the elevator shaft undergoes longitudinal motion to which the ele- vator structures must adapt themselves.

The object of the invention is to eliminate the draw- backs referred to above. A specific object of the in- vention is to disclose a new type of elevator landing door structure that is as simple as possible as well as cheap to manufacture and install.

As for the features characteristic of the invention, reference is made to the claims.

The landing door structure of the invention comprises a door sill attached to the lower edge of the landing door opening, an overhead supporter and at least one door panel movable along and supported by the overhead supporter. According to the invention, vertical frames are fixed to the door sill after it has been mounted in place on the floor, on either side of the door opening, and the overhead supporter is mounted on the vertical frames. In other words, the vertical frames are rigidly mounted and supported by the door sill.

Moreover, the vertical frames are fixed by their upper parts via junctures that are rigid in a horizontal plane but at the same time flexible or yielding in the vertical direction so that the effects of possible vertical movements of the shaft structure are freely transmitted via the junctures holding the upper part of the vertical frames.

The vertical frame is preferably attached by its upper part to another corresponding vertical frame which is mounted at the edge of the door opening on the next floor above and fixed to the door sill on that floor.

This fixture is so implemented that the vertical frames, disposed substantially one above the other as vertical extensions of each other, are rigidly con- nected to each other in the horizontal plane but the juncture between them permits sliding or yielding in

the longitudinal direction of the vertical frames as necessary due to thermal expansion and other movements occurring in the structures of the elevator shaft.

The length of the vertical frame is preferably so de- signed that it comprises an upper extension extending above the point of attachment of the overhead sup- porter, the vertical frame being fixed by said exten- sion via a juncture rigid in the horizontal plane.

Similarly, the vertical frame preferably extends below the point of attachment of the door sill so that the part of the vertical frame below the door sill forms a lower extension to which the upper end of the vertical frame at the edge of the door opening on the floor be- low can be attached.

The vertical frames vertically aligned with each other on different floors and forming extensions of each other can be connected to each other in a variety of ways. The essential point is only that the junctures ensure that the vertical frames are held rigidly in position in a horizontal plane while allowing vertical movements of the vertical frames in relation to each other. Thus, the juncture may consist of a suitable sleeve surrounding the vertical frames or a suitable clamp connection in which the vertical frames are locked between two elements pressed towards each other. Another essential point is that the vertical frames are not directly butted on each other; instead, a suitable gap is left between the vertical frames at the juncture. The vertical frame may be made of vari- ous types of rigid profile steel, such as U channel section, H section, T section or round or cornered tu- bular profile steel.

It is also possible within the scope of the inventive idea to fasten the vertical frame by its upper part

directly to the door sill fixed to the lower edge of the door opening on the floor above. In this case, too, the juncture is implemented as a structure that is rigid in the horizontal plane but capable of yield- ing appropriately in the vertical direction.

Especially in the case of an elevator door structure for the topmost floor and also in applications where the floor-to-floor distances are particularly large, the upper part of the vertical frame can be fastened directly to the shaft wall. In this embodiment, too, the juncture is so implemented that it is rigid in the horizontal plane but capable of yielding appropriately in the vertical direction.

The vertical frame is preferably attached to the end of the door sill. Likewise, the overhead supporter is preferably attached by its ends between the two verti- cal frames, although, depending on the installation space and the profile of the vertical frame used, other ways of implementing the attachment are possi- ble.

The elevator landing door structure of the invention provides significant advantages as compared with prior art. The door structure is very simple and easy to erect. After the door sills have been fitted in the landing door openings of the elevator shaft and fixed in place, no further accurate measurements are needed.

The vertical frames are provided with precise attach- ment points, e. g. perforations, both for the door sill and the overhead supporter. Thus, the vertical frames are fixed to the ends of the door sill and the over- head supporter is fixed to the upper ends of the ver- tical frames. At the same time, the upper ends of the vertical frames are connected to a corresponding ver- tical frame fixed to the door sill on the floor above.

In the following, the invention will be described in detail with reference to the attached drawings, which present diagrams of different embodiments of the ele- vator landing door structure of the invention.

The drawings present embodiments of the invention in a diagrammatic form comprising two floors. To give a clearer illustration of the actual inventive struc- ture, shaft structures such as door openings and land- ings are not shown in the figure.

Fig. 1 is a diagram representing an embodiment of the invention, showing a partial view comprising two floors, and Fig. 2 is a diagram representing another embodiment of the invention, showing a partial view comprising two floors, and Fig. 3 presents a magnified illustration of the solu- tion of the invention.

In the door structure in Fig. 1, a door sill 1 is fix- edly attached to the lower edge of the door opening on the lower floor by means of fastening elements 7. A corresponding door sill 5 is fixed to the lower edge of the door opening on the upper floor by means of fastening elements 8. After this, a rigid vertical frame 4 is fixed to one end of the door sill 1 and an identical vertical frame is also fixed to the other end of the door sill 1. Thus, the door sill 1 remains between the vertical frames 4. In the same way, an overhead supporter 2 is mounted between the vertical frames 4 at the upper edge of the door opening. The vertical frames 4 are provided with predesigned mount- ing holes or equivalent attachment points for both the

door sill 1 and the overhead supporter, so when these are to be installed, no measurements need to be car- ried out.

On the upper floor, in a corresponding manner, verti- cal frames 6 are fixed to either end of the door sill 5 and an overhead supporter 9 is fixed between the up- per parts of these vertical frames. The door panels 3 can then be suspended on the overhead supporters 2 and 9 in the normal manner.

The vertical frames 4 or the overhead supporter 2 are not fixed directly to the shaft structures at any point. Instead, the vertical frames 4 are attached by their upper ends to the lower ends of the vertical frames 6 mounted on the floor above, using clamps fit- ted to the profile shapes of the vertical frames 4 and 6, said clamps consisting of a clamping block 10 par- tially surrounding the U channel on its outer side and a counter block 11 fitted to the inner side of the U channels 4 and 6. These components are squeezed against each other by means of a bolt 12 so that the upper end of vertical frame 4 and the lower end of vertical frame 6 are clamped between them. In this way, a juncture is formed between the vertical frames 4 and 6 that is rigid in the horizontal plane but still capable of yielding in the longitudinal direc- tion of the vertical frames as necessary.

Thus, the entire weight of the door structure of the invention is transmitted via the door sill to the floor while the upper part of the door structure is only horizontally rigidly connected to the shaft structures via the door sill of the door structure above it.

In Fig. 2, shaft structures such as door openings and landings have been omitted to give a clearer illustra- tion of the actual inventive structure. In the door structure, a door sill 30 is fixedly attached to the lower edge of the upper floor door opening by means of fastening elements 31. After this, a rigid vertical frame 26 is fixed to one end of the door sill 30 and a similar vertical frame is also fixed to the other end of the door sill 30, leaving the vertical frames hang- ing. The door sill 30 thus remains between the verti- cal frames 26. The vertical frames 26 are provided with predesigned mounting holes for both the door sill 30, the intermediate door sill 25 and the overhead supporter 29, so when these are to be installed, no measurements need to be carried out.

In a corresponding manner, a door sill 25 is attached to the lower edge of the middle floor door opening by means of fastening elements 28. After this, a rigid first vertical frame 24 is fixed to one end of the door sill 25 and a similar vertical frame to the other end of the door sill 25, using fixing screws 32 which in the second vertical frame 26 go through a hole 36 and in the first vertical frame 24 through a hole 35 and the door sill 25, the vertical frames being left hanging. The second vertical frame 26 remains between the first vertical frame 24 and the door sill 25. The first vertical frame 24 hangs supported by the fixing screw 32 used as fastening element, and the clearance in the elongated hole 35 is below the screw 32. Thus, the vertical frames 24 and 26 are connected together by a screw joint which is rigid in the horizontal plane but is still capable of yielding in the longitu- dinal direction of the vertical frames as necessary when subjected to great forces. In a corresponding manner, the door sill 21 for the lower floor is fixed

to the lower edge of the door opening by means of fas- tening elements 27.

The elongated hole 36 shown in Fig. 3 is designed to allow for the manufacturing tolerance of the floor-to- floor distance in the building, ensuring that the pre- fabricated vertical frame will fit in place. Next, a hole is drilled through an initial hole in the door sill 25 and through the vertical frame 26, and a lock pin 34 serving as a fastening element is mounted to prevent movement of the door sill 25 and the second vertical frame 26 relative to each other. The first vertical frame 24 is provided with an elongated hole 37 in the region around the lock pin 34 so that the lock pin 34 does not touch the first vertical frame 24 and a significant portion of the clearance remains be- low the lock pin 34. The screw 32 and lock pin 34 used as fastening elements lock the first vertical frame 24 and the second vertical frame 26, which are provided with elongated holes 35 and 37, and the door sill 25 together and the lock pin 34 can move downward in the elongated hole 37.

Next, the overhead supporter 29 of the landing doors is mounted on the vertical frames 26. The door panels 23 can then be suspended on the overhead supporter 29 in the usual manner. The vertical frames 26 and the overhead supporter 29 are not fixed directly to the shaft structures at any point. Contraction of the building generates a large vertical force which will overcome the frictional force produced by the screw 32 used as fastening element, causing the door sill 25 attached to the landing floor to move downward. The second vertical frame 26, being connected to the door sill 25 with a lock pin 34, will follow the door sill, and the overhead supporter 29, being attached to the second vertical frame 26, will also follow the door

sill 25. The lock pin 34 can move freely downward in the elongated hole 37 in the first vertical frame 24.

The above description presents one arrangement de- signed to ensure that the sliding will occur between the lower vertical frame 24 on the one hand and the upper vertical frame 26 and the door sill 25 tied to- gether on the other hand, thus maintaining the dis- tance between the door sill 25 and the overhead sup- porter 29 unchanged.

The entire weight of the door structure of the inven- tion is transmitted via the door sill to the floor while the upper part of the door structure is only horizontally rigidly connected to the shaft structures via the door sill of the door structure above it.

In the foregoing, the invention has been described by way of example with reference to the attached drawing while different embodiments of the invention are pos- sible within the scope of the inventive idea defined in the claims.