FIREPROOFING FOR AN ELEVATOR LANDING DOOR

Abstract: Fireproofing arrangement for an elevator landing door, said landing door comprising a skin plate (1) facing toward the landing and a steel section reinforcement (3) laid in the vertical direction of the door and attached to the skin plate. The surface of the steel section reinforcement (3) on the side facing toward the shaft is provided with a layer of paint (5) becoming foamy when exposed to heat.

Description: FIREPROOFING FOR AN ELEVATOR LANDING DOOR The present invention relates to a fireprooflng arrange ¬ ment for an elevator landing door as defined m the pre ¬ amble of claim 1. Elevator doors are generally manufactured from non- combustible materials. Although they cannot catch fire, additional thermally insulating and fire retarding mate ¬ rials are generally used m them, m the first place to obstruct the propagation of fire and emergence of flames and to give more time for people to escape. In practice, fire resistance of a door means a parti ¬ tioning capacity. Partitioning is a central concept m fire technical design of buildings. Partitioning is used to restrict a fire that has already broken out so as to contain it within a certain area for a required length of time to allow time for rescue and firefightmg ef ¬ forts and to avoid unnecessary damage. The door panels of an elevator door are generally pro ¬ vided with a layer of mineral wool on the shaft- side face of the metal plate forming the door surface on tne side facing toward the landing, the door panel having a total thickness of e.g. about 20-30 mm. However, the door panel has to be provided with steel section rein ¬ forcements to stiffen the door panel. The steel section reinforcement is of a thickness substantially equal to that of the door panel, so it forms an effective heat transfer path through the insulating layer. The faster door panel could be provided with additional insulation on the steel section rein orcement on the shaft-side surface as there is sufficient space for it, whereas no such space is available on tne slower door panel as the faster door panel moves m direct contact with the surface of the insulation on the slower door panel . To eliminate these problems, the landing- side surface the skin plate of at least the slower door panel is treated with flame-proofing paint, i.e. a substance that, when exposed to heat, expands and forms foamy in ¬ sulating material. This insulation is intended to pre ¬ vent the main steel structure of the door from being heated and to stop heat transfer via the heat transfer path formed by the reinforcing steel section. However, this prior-art structure has obvious drawbacks. As the flame-proofing paint is visible on the surface of the skin plate and is therefore exposed to touch and wear, t is unlikely to remain completely intact and re- tain a uniform thickness through the years, as is re ¬ quired of high-quality fire insulation. In addition, m a fire situation, flames at the landing w ll come in di ¬ rect contact with the paint layer, most fireprooflng paints being combustible. Thus, m the event of a fire, they quickly lose their efficiency and functionality as a fireprooflng or fire retarding structure. The object of the present invention is to eliminate the above-mentioned drawbacks. A specific object of the pre ¬ sent invention is to disclose a new type of fireprooflng arrangement for an elevator landing door that is reli ¬ able and endures for years. As for the features characteristic of the present inven ¬ tion, reference is made to the claims. In the fireprooflng arrangement for an elevator landing door according to the present invention, the landing door comprises a skin plate facing toward the landing and a steel section reinforcement laid in the vertical direction of the door and attached to the skin plate. According to the invention, the shaft-side surface of the reinforcing steel section is provided with a layer of fireprooflng paint, i.e. paint that becomes foamy when heated. Thus, the invention is based on the new ba- sic idea that the door is only designed to stop the propagation of heat beyond the door, without regard to the steel structure of the door itself becoming heated. Thus, the fireprooflng paint can be applied to the shaft-side surface of the door so that it remains out of sight and is not exposed to touch and wear but is pre ¬ served unchanged. The foaming fireprooflng paint can be applied directly to the shaft-side surface of the reinforcing steel sec ¬ tion. Another possibility is to attach a separate plate to the shaft-side surface of the reinforcing steel sec ¬ tion e.g. by means of screws and then treat the surface of this plate with foaming paint. The door is preferably provided with thermal insulation placed on the shaft-side surface of the skin plate. In this case, the reinforcing steel section preferably ex ¬ tends through the thickness of the thermal insulation. The reinforcing steel section may comprise a shaft-side surface which is substantially parallel to the skin plate and to which the fireprooflng paint is applied. This surface may be substantially flush with the shaft- side surface of the rest of the thermal insulation of the door. In an embodiment of the invention, the steel section re ¬ inforcement consists of a box m which the reinforcing plate formed by the shaft-side surface is connected to the skin plate of the door e.g. by oblique side plates so that the cross-section of the reinforcement is a trapezoid tapering toward the shaft. In this case, fire- proofing paint can also be applied to the side plate surfaces facing obliquely toward the shaft. It is also possible to use fireprooflng paint on the other surfaces of the steel section reinforcement as well, i.e. on the surfaces facing e.g. squarely or obliquely toward the skin plate. In an embodiment of the invention, fireprooflng paint is applied to the entire shaft-side surface of the skin plate, whereupon thermal insulation can be mounted on it or it may be left without insulation. As compared with prior art, the fireprooflng arrangement of the present invention has significant advantages. The fireprooflng can be so placed on the landing door that it remains out of sight and is therefore not susceptible to wear. Thus, the fireprooflng is preserved intact and in good working order for a long time. Furthermore, m fire situations, the fireprooflng paint will not come into direct contact with flames but only into thermal contact via steel structures, so it will be preserved unburned and function as insulation for a considerably longer period than the fireprooflng paints used m cur ¬ rent solutions. In the following, the invention will be described m de ¬ tail by referring to the attached drawing, which pres ¬ ents a cross-section of a fireprooflng arrangement on an elevator landing door according to the invention. In the embodiment m Fig. 1, the slow door panel 11 and the fast door panel 12 have an identical basic struc ¬ ture. They comprise a skin plate 1 generally made of steel, placed on the side of the door facing toward the landing. Attached by its flanges 13 to the shaft-side surface of the skin plate 1 is a steel section rein ¬ forcement 3, which consists of a reinforcing plate 4 parallel to the skin plate 1 and oblique side plates 7. Both door panels are provided with thermal insulation 2 placed on the side of the sk n plate 1 facing toward the shaft, the thickness of the insulating layer being sub ¬ stantially the same as the thickness of the steel sec ¬ tion reinforcement 3. The faster door panel 12 is pro- vided with additional insulating material 14 m the area of the steel section reinforcement 3. The additional in ¬ sulation prevents thermal leakage through the steel sec ¬ tion reinforcement from the landing to the shaft. In the slower door panel 11, additional insulation 15 can be used inside the steel section reinforcement 3 to reduce thermal leakage through the reinforcement. How ¬ ever, it does not significantly prevent thermal leakage through the slower door panel. The slower door panel 11 cannot be provided with the type of insulation 14 used on the faster door panel 12 because the door panels travel at an almost zero distance from each other, leav ¬ ing no space for such insulation. To avoid thermal leakage through the steel section rein ¬ forcement 3 from the landing into the shaft, the shaft- side outer surface of the reinforcing plate 4 is coated with fireprooflng paint 5, i.e. with a layer of paint that becomes foamy when exposed to heat. It is also pos ¬ sible to extend the layer of fireprooflng paint so as to form paint layers 8 covering the shaft-side oblique sur- faces of the side plates 7 of the steel section rein ¬ forcement 3. If the insulating effect of the fireprooflng paint is to be further enhanced, then a layer of paint 9 becoming foamy when exposed to heat can also be applied to the landing-side surface of the reinforcing plate 4, and similarly the landing-side surfaces of the skin plate 1 and of the reinforcement 3 flanges 13 attached to it can be provided with a layer of paint 10 becoming foamy when exposed to heat. As an alternative structure, Fig. 1 shows a plate 16 provided with a layer of paint 17 becoming foamy when exposed to heat, which plate can be attached e.g. with screws to the shaft-side surface of the steel section reinforcement 3 instead of applying a layer such paint directly to that surface. Of course, the fast door panel 12 may also be provided with a layer of foaming paint according to the present invention, especially when no heat insulation is used m either one of the door panels. The fireprooflng paints, .e. the layers of paint oecom- mg foamy when exposed to heat, used m the invention may consist of various known products applicable for this use, which will not be described m detail n this application. The invention has been described above by way of example by referring to the attached drawing, but different em ¬ bodiments of the invention are possible within the scope of the inventive idea defined m the claims.

Claims: CLAIMS 1. Fireprooflng arrangement for an elevator landing door, said landing door comprising - a skin plate (1) facing toward the landing and - a steel section reinforcement (3) laid m the vertical direction of the door and attached to the skin plate, characterised m that the surface of the steel section reinforcement (3) on the side facing toward the shaft is provided with a layer of paint (5) becoming foamy when exposed to heat. 2. Fireprooflng arrangement as defined in claim 1, characterised in that thermal insulation (2) is provided on the side of the skin plate (1) facing toward the shaft while the steel section reinforcement (3) ex- tends substantially through the thickness of the thermal insulation. 3. Fireprooflng arrangement as defined m claim 1, characterised m that the layer of paint (5) is on the side of the steel section reinforcement (3) facing toward the shaft. 4. Fireprooflng arrangement as defined m claim 1, characterised m that the layer of paint is on a plate (16) attached to or supported by the surface of the steel section reinforcement (3) on the side facing toward the shaft. 5. Fireprooflng arrangement as defined m any one of claims 1 - 4, characterised m that the surface (4) of the steel section reinforcement (3) facing toward the shaft is substantially parallel to the skin plate (1). 6. Fireprooflng arrangement as defined m any one of claims 2 - 5, characterised m that the surface (4) of the steel section reinforcement (3) facing toward the shaft is substantially flush with the surface (6) of the thermal insulation (2) facing toward the shaft. 7. Fireprooflng arrangement as defined m any one of claims 1 - 6, characterised m that the steel section reinforcement (3) consists of a box m which the reinforcing plate (4) formed by the shaft-side surface is connected to the skin plate (1) by oblique side plates (7) . 8. Fireprooflng arrangement as defined in claim 7, characterised m that a layer of paint (8) becom ¬ ing foamy when exposed to heat is provided on the sur- faces of the side plates (7) obliquely facing toward the shaft. 9. Fireprooflng arrangement as defined m claim 7 , characterised m that a layer of paint (9) becom ¬ ing foamy when exposed to heat is provided on the sur- face of the reinforcing plate (4) facing toward the skin plate (1) . 10. Fireprooflng arrangement as defined m any one of claims 1 - 9, characterised m that a layer of paint (10) becoming foamy when exposed to heat is pro- vided on the surface of the skin plate (1) facing toward the shaft.

Inventors: KETONEN ARI, KETONEN, ARI
Applicants: KETONEN ARI, KONE CORP, KETONEN, ARI, KONE CORPORATION
Application year: 1999
Main classification: E06B5
IPC codes: B66B13, E06B5