The present invention relates to an elevator door mechanism arrangement as defined in the preamble of claim 1.

One of the problems with prior-art door mechanism arrangements in elevators is that the door mechanism requires a vertical space above the top of the elevator car. The reason why a ver¬ tical space is needed is in many cases the fact that the up¬ right operating motor of the door mechanism requires a verti¬ cal space. The required additional height means that the ele¬ vator shaft has to be correspondingly higher by the same amount so that the highest position of the elevator car will be in accordance with elevator norms. Accordingly, additional height in the elevator shaft rapidly increases the construc¬ tion costs.

US patent US5,678,660 discloses a prior-art door mechanism arrangement, wherein the door operating motor is in an upright position. Figures 2-8 of this US patent present different door mechanism arrangements, which all show a door mechanism oper¬ ating motor mounted in an upright position. Although the ar¬ rangement disclosed in the US patent does lead to a narrow door mechanism structure, there remains the above-mentioned problem of vertical space requirement, necessitating a higher and more expensive elevator shaft.

Similarly, kv.patent specification no. WO00/39017 describes another prior-art door mechanism arrangement, wherein the op¬ erating motor of the door mechanism is of flat construction and disposed in the forepart of the elevator car. According to this patent specification, the operating motor of the door mechanism may be placed at different heights in the forepart of the elevator car. This specification aims at solving the above-mentioned problem resulting from the vertical space re¬ quirement, but the non-standard flat operating motor used is relatively expensive for this purpose and thus increases the costs of the elevator. Likewise, the different mounting heights of the operating motor necessitate complicated and therefore expensive door mechanism arrangements that also re¬ quire a great deal of maintenance.

The object of the present invention is to overcome the above- mentioned drawbacks and to create a door mechanism arrangement of economical cost that is easy to produce and enables a low construction, providing more overhead space and allowing the elevator shaft to made lower than normal. The door mechanism arrangement of the invention is characterized by what is dis¬ closed in the characterization part of claim 1. Other embodi¬ ments 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 disclosed 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, espe¬ cially if the invention is considered in the light of explicit or implicit sub-tasks or in respect of advantages or sets of advantages achieved. In this case, some of the attributes con¬ tained in the claims below may be superfluous from the point of view of separate inventive concepts. Correspondingly, dif¬ ferent details presented in connection with each embodiment example can also be applied in other embodiments as well.

The door mechanism arrangement of the invention, which com- prises at least a supporting structure supporting the door mechanism, an operating motor of the elevator door, at least one door leaf, a door leaf supporting element, bearing rollers rotatably mounted with bearings on the supporting element and at least one roller race provided with guide surfaces, the door leaf being suspended on said roller race via said bearing rollers, and which door mechanism arrangement additionally comprises elements transmitting the rotary motion of the oper¬ ating motor into opening and closing motion of the door leaf of the elevator. According to the invention, the operating motor of the elevator door is placed in the upper part of the supporting structure of the door mechanism in such manner that the axis of rotation of the operating motor extends in a sub¬ stantially horizontal plane and that, as seen from the land¬ ing, the operating motor is placed substantially behind the supporting structure of the door mechanism of the elevator.

In an embodiment of the invention, the supporting structure of the door mechanism arrangement of the elevator comprises a substantially horizontally disposed overhead supporting beam, to the back side of which is secured the operating motor of the elevator door in such manner that the rotating shaft of the operating motor is fitted through the back wall of the overhead supporting beam to the front side of the overhead supporting beam.

In an embodiment of the invention, the operating motor of the elevator door is a standard-type electric motor.

In an embodiment of the invention, the element transmitting the opening and closing motion of the elevator door leaf con¬ sists of a belt pulley and a cogged belt, the door leaf being connected to the upper and/or lower surface of said cogged belt via a supporting element and a supporting arm.

The advantages of the door mechanism arrangement of the inven¬ tion include a simple and low door mechanism structure assem¬ bled from standard parts that enables a lower space above the elevator car and at the same time an elevator shaft of lower height, thus also reducing the construction costs of the ele¬ vator shaft. Moreover, the lower construction allows the use of a lower and lighter overhead supporting beam, which means that the weight of the elevator car is reduced, which again leads to many other advantages.

In the following, the invention will be described in detail with reference to an embodiment example and the attached draw¬ ings, wherein

Fig. 1 presents a side view of the door mechanism ar¬ rangement of the invention, Fig. 2 presents a partially sectioned front view of- the door mechanism arrangement in Fig. 1, and Fig. 3 presents a side view of another door mechanism arrangement according to the invention.

Figures 1 and 2 present a door mechanism arrangement imple¬ menting the concept of the invention. The door in question is a two-leaf, middle-opening elevator car door, the supporting structure 1 of which door mechanism arrangement is secured to the forepart of the elevator car. In the door mechanism struc¬ ture presented in Fig. 1 and 2, the door leaf 11 is located substantially directly opposite to the aperture of the eleva¬ tor car and the actual supporting structure 1 of the door mechanism is placed above the door leaf 11, extending from the upper edge of the aperture towards the top of the elevator car. Due to its low construction, the highest point of the supporting structure 1 is as close to the top of the elevator car as possible, so the elevator car can rise to a position very close to the ceiling of the elevator shaft. The operating motor 3 of the door mechanism is placed either immediately above the top of the elevator car or, depending on other structural solutions, on one side of the elevator car below the top of the elevator car.

In addition to the above-mentioned supporting structure 1 and operating motor 3, the door mechanism arrangement of the in¬ vention comprises at least an overhead supporting beam 2, a transmission element, such as a cogged belt 5 and belt pulleys 4 and 15 for implementing the opening and closing motion of the elevator door, and at least one roller race 6, all these components being mounted in conjunction with the supporting structure 1. The substantially horizontal overhead supporting beam 2 comprised in the supporting structure 1 of the door mechanism has a width preferably at least equal to the width of the elevator car. The overhead supporting beam 2 is fixedly secured e.g. to the structures of the elevator car. In cross- section, the overhead supporting beam 2 is a structure having e.g. the shape of a U-beam standing on one of its side edges, and the operating motor of the door mechanism is secured to the web of the overhead supporting beam on the side of the elevator car, i.e. to the back side of the supporting struc¬ ture 1 of the door mechanism as seen from the landing, in such manner that the operating motor 3 and its rotating shaft are in a substantially horizontal position. The operating motor 3 is e.g. a standard-type electric motor. The rotating shaft of the operating motor 3 has been fitted to extend through the web plate of the overhead supporting beam 2 to the front side of the door mechanism. Mounted on the rotating shaft is a belt pulley 4, preferably e.g. a cogged belt pulley, fitted to ro¬ tate with the rotating shaft and functioning as a driving pul¬ ley. The belt pulley 4 is preferably small enough to fit in¬ side the cross-section of the overhead supporting beam 2, so it does not take up any additional space in the frontward di¬ rection of the door mechanism.

Fixedly attached by its upper surface to the lower edge of the overhead supporting beam 2 is a substantially horizontal roller race 6, which in English is also termed "railing". The roller race 6 is a metal structure having a length substan¬ tially equal to the length of the overhead supporting beam 2 and in cross-section so bent that the roller race has both upward and downward guide surfaces for the bearing and counter rollers 9 and 10 of the door leaf 11. The bearing rollers 9 are fitted to run on the upward guide surface and the counter rollers 10 are fitted to run along the downward guide surface. The bearing and counter rollers 9 and 10 are placed in sub¬ stantially the same vertical plane.

The door leaf 11 is suspended e.g. on two bearing rollers 9 via a bearing plate 7 functioning as a supporting element, the bearing rollers 9 being mounted with bearings on the bearing plate 7. Similarly, the counter rollers 10 are mounted with bearings on the same bearing plate 7. The door leaf 11 is se¬ cured by its upper edge to the lower edge of the bearing plate by means of a screw fastening e.g. using e.g. a mounting sup¬ port 12.

The element implementing the opening and closing motion of the door leaves 11 in the door mechanism arrangement is an endless cogged belt 5 functioning as a motion transmitting element, which is driven alternately in two opposite directions by the door operating motor 3. The cogged belt 5 has been fitted to rotate over both the belt pulley 4 functioning as a driving pulley and the freely rotating belt pulley 15 at the other end of the belt loop. The door leaf 11 is connected to the cogged belt 5 by connecting lugs 7a, 78 extending upwards from the upper part of the bearing plates 7 and 8 functioning as sup¬ porting elements. The door leaves 11 of the middle-opening door are connected to the cogged belt in such manner that the connecting lug 7a of the first door leaf is fastened to the lower belt portion of the loop formed by the cogged belt 5 while the connecting lug 8a of the second door leaf is fas¬ tened to the upper belt portion of the loop formed by the cog¬ ged belt 5. Thus, the connecting lug 7a of the first door leaf is fastened to a portion of the cogged belt 5 that moves in one direction and the connecting lug 8a of the second door leaf is fastened to a portion of the cogged belt 5 that moves in the opposite direction, so that, depending on the direction of rotation of the cogged belt 5, the door leaves move either away from or towards each other.

Fig. 2 additionally presents a door mechanism control unit 13 for control of the door operating motor 3 and supply of power, as well as a door coupler 14 mounted on the bearing plate 8 of the second door leaf. The door coupler transmits the motion of the car door to the landing door, the latter having a counter- piece for the door coupler 14 on a corresponding bearing plate supporting the door leaf. Thus, the car door and the landing door are opened and closed substantially simultaneously, and no separate operating motor is needed for the landing door.

Fig. 3 presents a side view of the door mechanism arrangement of the invention fitted for a three-leaf telescoping door in which all the door leaves lla-llc move simultaneously in the same direction. In this solution, the overhead supporting beam 2, the door operating motor 3, the belt pulley 4 and the cog¬ ged belt 5 may be substantially identical to those in the em¬ bodiment described above in respect of construction, placement and functions. Programmed in the control unit is a control arrangement corresponding to the door solution.

Attached to the lower edge of the overhead supporting beam 2 in the solution illustrated in Fig. 3 are two parallel roller races 6a and 6b, which substantially correspond to the roller race 6 described above. The bearing rollers 9a of the outer¬ most door leaf 11a are fitted to run on the upward guide sur¬ face of roller race 6a and the counter rollers 10a are fitted to engage the downward guide surface. The bearing and counter rollers 9a and 10a are in substantially the same vertical plane. The outermost door leaf 11a is suspended in position on the bearing rollers 9a via a suspension plate 20 functioning as a supporting element, both the bearing rollers 9a and the counter rollers 10a being rotatably mounted with bearings on the suspension plate 20.

Similarly, the middle door leaf lib is suspended on its bear¬ ing rollers 16 via a suspension plate 18 functioning as a sup¬ porting element and fastened to the upper edge of door leaf lib. Rotatably connected to the upper part of the suspension plate 18 are bearing rollers 16, which are fitted to run on the opposite side of roller race 6a relative to the bearing and counter rollers 9a, 10a of the outermost door leaf 11a. On this aforesaid opposite side are second guide surfaces placed oppositely to each other, with bearing rollers 16 fitted to run between them.

Like the middle door leaf lib, the innermost door leaf lie is suspended on bearing rollers 17 via a suspension plate 19 functioning as a supporting element and fastened to the upper edge of door leaf lie. Rotatably connected to the upper edge of the suspension plate 19 are bearing rollers 17 fitted to run between the mutually opposite guide surfaces of the second roller race 6b, which are placed on the side facing towards the elevator car.

The outermost door leaf 11a connected via a connecting arm 20a in the upper part of suspension plate 20 to the cogged belt 5 implementing the opening and closing motion of the door leaves. Thus, the outermost door leaf 11a moves in the opening and closing directions according to the direction of rotation of the cogged belt 5. The door mechanism solution is imple¬ mented e.g. in such manner that the outermost door leaf 11a is provided with a door coupler while the other door leaves lib, lie are provided with a door coupler counterpart, so that when the outermost door leaf 11a moves in the opening direction, it engages the other door leaves lib, lib in turns, and when the outermost door leaf lla moves in the closing direction, it engages the other door leaves lib, lie in turns in the reverse order.

It is obvious to the person skilled in the art that the inven¬ tion is not limited to the embodiments described above, in which the invention is described by way of example, but that it may be varied within the scope of the inventive concept defined in the claims presented below. Thus, the door mecha¬ nism arrangement and door structures may differ from the above description. For example, the door may comprise only one door leaf or more than three door leaves as mentioned. In addition, the door may be a middle-opening telescoping door. Likewise, the roller races and other mechanical structures may differ W

10

from the above description.

It is further obvious to the skilled person that, instead of a cogged belt as referred to above, the transmission element may also be any other suitable transmission element, such as a trapezoidal belt, a rope, a chain, a toothed rack or equiva¬ lent, in which case the actuating mechanisms associated with the transmission element may also differ from those described above.