Foldable stairs embedded in a frame

Description

[0001] The present invention relates to foldable stairs, in particular a ladder-like stairs embedded in a substantially horizontal frame mounted in a ceiling, and in particular in a deep frame apt to a thick ceiling such as ceiling provided with thermal insulation. Stairs of this kind are used mainly as attic entrances.

BACKGROUND OF THE INVENTION

[0002] Patent specification GB 2 319 051 discloses a folding attic stairway comprising three stairway portions connected by hinges, where the upper stairway portion is mounted on the inner stairway carrying frame which is pivotally mounted by a hinge on the outer frame for mounting in a ceiling open. The uppermost step of these stairs is the uppermost step of the upper stairway portion mounted to the inner stairway carrying frame. Also the Polish patent specification PL 199927 B1 discloses foldable stairs having the uppermost step fixed to the uppermost stairs segment.

[0003] CH 259760 discloses a foldable stairs according to the preamble of claim 1.

[0004] If there is a need to use a deep stairway carrying frame, e.g. to be mounted in a ceiling provided with thick thermal insulation, the height between the uppermost step of the stairs and the top edge of the frame is known, prior art solutions substantially extend the step pitch of the stairs.

[0005] In particular, the objects are achieved by foldable stairs according to claim 1 Preferred embodiments are subject of the dependent claims.

SUMMARY OF THE INVENTION

[0006] The invention provides foldable stairs embedded in a frame, in particular in a deep frame having increased wall height, comprising stairs segments movable with relation to each other, wherein the uppermost stairs segment is rotationally connected with the frame, which are provided with a movable step pivotally connected to the internal surface of the wall of the frame. The uppermost stairs segment is attached to the cover that closes said frame at the bottom thereof in the stairs closed state and is connected by means of a hinge mechanism with the frame and the movable step is supported by at least one supporting element connected to the cover. The geometrical axis of the stringers of the uppermost segment of the stairs unfolded for use thereof, crosses the top surface of the stair tread of the movable step in the proximity of the centre of the tread width. The movable step can be positioned in such a manner that the distance between the tread of the movable step and the tread of the uppermost step of the uppermost stairs segment substantially corresponds to the step pitch of the stairs.

[0007] In the stairs closed state, remaining stairs segments are positioned within the frame, above the uppermost stairs segment and in the stairs unfolded, opened state remaining stairs segments are positioned below the uppermost stairs segment in an aligned relation forming a sloped line of stairs. The stairs can also be provided with a mechanism, preferably a spring mechanism, that supports lifting up of folded stairs to the stairs closed state and at least partially counterbalances the weight of the stairs during opening thereof. Preferably the stairs are also provided with tie rod arrangement that restricts the opening limits of the stairs.

[0008] According to a first alternative of the invention, said supporting element of the movable step is the uppermost stairs segment and the movable step is supported by hinged connectors coupling the uppermost stairs segment, preferably stringers of this segment, with the movable step. In the opened state of the stairs (unfolded for use) the hinged connectors are substantially aligned with the stringers of the uppermost stairs segment. The geometrical axis of the stringers of the uppermost segment of the stairs crosses the top surface of the tread of the movable step in the proximity of the centre of its width so that the pressure on this step is transferred mainly on the uppermost stairs segment and only to a limited extent through the joint of this step on the frame mounted in a ceiling.

[0009] According to a second alternative of the invention, said supporting element of the movable step is the uppermost stairs segment and the movable step is provided with supporting legs and in the opened state of the stairs the supporting legs are substantially aligned with the stringers of the uppermost segment of the stairs and abut the frontal top surfaces of the stringers. In the opened state of the stairs unfolded for use the geometrical axis of the stringers of the uppermost segment of the stairs crosses the top surface of the tread of the movable step in the proximity of the centre of the width of the tread which has the same advantageous effect of transferring pressure as in the embodiment above. In the closed (folded) state of the stairs the tread of the movable step adheres to the frame wall from inside and the supporting legs have no contact with the uppermost segment of the stairs.

[0010] According to a third alternative of the invention, said supporting element of the movable step is at least one bracket attached to the cover connected by means of a hinge mechanism with the frame. The movable step is supported by hinged connectors coupling the movable step with this bracket or brackets. The hinged connectors are substantially aligned with the stringers of the uppermost stairs segment in the opened state of the stairs. The width of the tread of the movable step as well as the distance between the tread and the inside surface of the frame are selected in such a manner that the geometrical axis of the stringers of the uppermost segment of unfolded stairs crosses the top surface of this tread in the proximity of the centre of the width thereof which has the same advantageous effect of transferring pressure as in the embodiments above.

[0011] The foldable stairs with an additional movable step according to the present invention are much more convenient than known stairs since the movable step facilitates walking up onto the surface above the frame.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The invention is illustrated below with reference to the preferred embodiments thereof that should not be considered in any way as limitative and with reference to the attached drawings on which:

Fig. 1 shows an axonometric schematic view of the first embodiment of the foldable stairs according to the first alternative of the invention having a movable step and hinged connectors, in opened state but with stairs segments folded on the cover,

Fig. 2 shows a side view of the stairs from Fig. 1 in opened state but with stairs segments in intermediate state of opening or closing,

Fig. 3 shows a side view of the stairs from Fig. 1 almost in closed state with stairs segments folded on the cover,

Fig. 4 shows a side view of the stairs from Fig. 1 in closed state with stairs segments folded on the cover,

Fig. 5 shows a side view of an embodiment of the foldable stairs according to the second alternative of the invention having a movable step with supporting legs fixed to a movable step tread in opened state but with stairs segments folded on the cover, and

Fig. 6 shows a side view of the stairs from Fig. 5 in closed state with stairs segments folded on the cover.

[0013] An embodiment of the foldable stairs according to the third alternative of the invention has not been depicted on the drawings but is thoroughly described with reference to the common and different features of the embodiments illustrated on drawings.

Embodiment 1

[0014] Foldable stairs shown in Fig. 1 comprise a frame 1 embedded horizontally in a ceiling of a building, wherein the walls of the frame are relatively deep due to a thick ceiling or necessity of providing that the walls extend over the top surface of the ceiling. From the bottom, the frame 1 can be closed by a cover 2 which is connected to the frame by means of a hinge mechanism and tie rod arrangement that restricts the opening limits of the cover 2. The arrangement connecting the frame 1 with the cover 2 also comprises springs that support lifting up the cover with folded stairs segments to the closed state and also counterbalance the weight of the cover 2 and the stairs during opening thereof. In this embodiment the stairs comprise three segments, wherein the uppermost stairs segment 3 is fixed to the cover 2. The number of segments and a method of connection between the segments and the cover are irrelevant to the subject of the present invention.

[0015] Within the interior of the frame 1 a movable step 4 is positioned. The movable step 4 is pivotally connected to the internal surface of the wall of the frame 1 and supported on the uppermost stairs segment 3 by means of two hinged connectors 5 that connect stringers (side beams) of this segment with lugs of the movable step 4 located below a tread 41 of the movable step 4. In opened state of the stairs, the hinged connectors 5 are substantially aligned with the stringers of the uppermost stairs segment 3 (cf. Fig. 1 and Fig. 2) wherein the tread 41 of the movable step 4 is oriented substantially horizontally as the treads of the remaining steps of unfolded stairs segments.

[0016] The width of the tread 41 as well as the distance between the tread 41 and the inside surface of the frame 1 are selected in such a manner that the geometrical axis of the stringers of the uppermost segment 3 of the stairs crosses the top surface of the tread 41 in the proximity of the centre of its width. The distance between the tread 41 of the movable step and a tread 31 of the uppermost step of the uppermost stairs segment 3 is selected to correspond to the step pitch of the stairs.

[0017] When the folded stairs are lifted in order to place them within the frame 1, the hinged connectors 5 lift up the movable step 4 (cf. Fig. 3), and in closed state where the cover 2 is closed and stairs segments are positioned in the frame 1, the connectors are oriented substantially vertically. Also the stair tread 41 is then oriented substantially vertically inside the frame 1 in a close proximity of the frame wall (cf. Fig. 4).

[0018] The foldable stairs are additionally provided with a telescopic handrail (not shown in the drawings) which is jointedly connected with two segments of the stairs. A spring positioned inside the handrail supports lifting up and folding all the stairs segments but the uppermost one, as well as counterbalances the weight of these segments while unfolding the stairs.

Embodiment 2

[0019] Similarly as in the Embodiment 1 foldable stairs presented in Fig. 5 comprise a deep walled frame 1 embedded horizontally in a ceiling of a building and closable from the bottom by a cover 2 connected to the frame by a hinge mechanism and tie rod arrangement that restricts the opening limits of the cover 2. The uppermost stairs segment 3 is fixed to the cover 2 and in this embodiment the stairs also comprise three segments but obviously the number of segments and their mutual connections are irrelevant to the subject of the present invention.

[0020] A movable step 6 is connected pivotally inside the frame 1 at the internal surface of the wall thereof and supported by the uppermost stairs segment 3 by means of two supporting legs 61 fixedly connected to the movable step 6. When the stairs are in the opened state the supporting legs 61 are substantially aligned with the stringers of the uppermost stairs segment 3 (cf. Fig. 5) wherein a tread 62 of the movable step 6 is oriented substantially horizontally as the treads of the remaining steps of unfolded stairs segments.

[0021] The width of the tread 62 as well as distance between the tread 62 and the inside surface of the frame 1 are selected in such a manner that the geometrical axis of the stringers of the uppermost segment 3 of the stairs crosses the top surface of the tread 62 in the proximity of the centre of its width. The distance between the tread 62 of the movable step and a tread of the uppermost step of the uppermost stairs segment 3 is selected to correspond to the step pitch of the stairs (i.e. the rise height of the stars). Additionally the supporting legs 61 can be provided with a mechanism for adjusting their length, e.g. by means of adjusting screws driven from the side of the stringers of the uppermost segment 3. The foldable stairs are additionally provided with a telescopic handrail (not shown in the drawings) as in the Embodiment 1.

[0022] Folding the stairs in order to hide them within the frame 1 should be preceded by turning the movable step 6 to a position in which its tread 62 is oriented substantially vertically inside the frame 1 close to the frame wall (cf. Fig. 6). In this position the supporting legs 61 of the movable step 6 will be positioned above the space provided for the stair segments in closed state of the stairs.

Embodiment 3

[0023] Similarly as in the Embodiment 1 foldable stairs comprise deep walled frame embedded horizontally in a ceiling of a building and closable from the bottom by a cover connected to the frame by a hinge mechanism and tie rod arrangement that restricts the opening limits of the cover. The uppermost stairs segment is fixed to the cover.

[0024] Furthermore brackets are fixed to the cover alongside stringers (side beams) of the uppermost stairs segment.

[0025] Within the interior of the frame a movable step is positioned. The movable step is pivotally connected to the internal surface of the wall of the frame and supported on the brackets by means of two hinged connectors that connect the brackets with lugs of the movable step located below a tread of the movable step.

[0026] The width of the tread of the movable step as well as the distance between this tread and the inside surface of the frame are selected in such a manner that geometrical axis of the stringers of the uppermost segment of the unfolded stairs crosses the top surface of the tread in the proximity of the centre of its width. Functionality of the movable step in all its positions is identical as in the Embodiment 1. Similarly as in the Embodiment 1 the foldable stairs are additionally provided with a telescopic handrail.

Claims

1. Foldable stairs embedded in a frame (1), in particular in a deep frame having increased wall height, comprising stairs segments movable with relation to each other, wherein the uppermost stairs segment (3) is rotationally connected with the frame (1) by means of a hinge mechanism, while the remaining stairs segments are positioned within said frame (1) in the stairs closed state, wherein within the frame (1) a movable step (4, 6) is positioned, pivotally connected to the internal surface of the wall of the frame (1), wherein the geometrical axis of the stringers of the uppermost segment (3) of the stairs unfolded for use thereof, crosses the top surface of the stair tread (41, 62) of the movable step (4, 6) in the proximity of the centre of the tread (41, 62) width, characterized in that the uppermost stairs segment (3) is attached to a cover (2) that closes said frame (1) at the bottom thereof in the stairs closed state,
that the moveable step (4, 6) is supported by at least one supporting element connected with the cover (2),
further characterised in that
either

(i) said supporting element of the movable step (4, 6) is the uppermost stairs segment (3), wherein the movable step (4) is supported by hinged connectors (5) coupling the uppermost stairs segment (3) and preferably stringers of this segment (3) with the movable step (4), wherein in the opened state of the stairs the hinged connectors (5) are substantially aligned with the stringers of the uppermost stairs segment (3);
or

(ii) said supporting element of the movable step (4, 6) is the uppermost stairs segment (3), wherein the movable step (6) is provided with supporting legs (61) fixed to the tread (62) of the step (6), wherein in the opened state of the stairs the supporting legs (61) are substantially aligned with the stringers of the uppermost segment (3) of the stairs and abut the frontal top surfaces of the stringers;
or

(iii) said supporting element of the movable step is at least one bracket attached to the cover, wherein the movable step is supported by hinged connectors coupling said at least one bracket attached to the cover with the movable step, wherein in the opened state of the stairs the hinged connectors are oriented in parallel to the stringers of the uppermost segment of the stairs.

2. The foldable stairs according to claim 1, characterized in that the distance between the stair tread of the movable step (4, 6) and the stair tread of the uppermost step (31) of the uppermost segment (3) of the stairs substantially corresponds to a step pitch of the stairs.

3. The foldable stairs according to any preceding claim, wherein the stairs are provided with a mechanism that supports lifting up of the folded stairs to the stairs closed state and at least partially counterbalances the weight of the stairs during opening thereof.

4. The foldable stairs according to claim 3, wherein the mechanism that supports lifting up is a spring mechanism.

5. The foldable stairs according to any preceding claim, wherein the stairs are provided with a tie rod arrangement that restricts the opening limits of the stairs.

Ansprüche

1. Klapptreppe, in einen Rahmen (1) eingelassen, insbesondere in einem tiefen Rahmen mit einer erhöhten Wand, umfassend Treppensegmente, sich gegeneinander bewegende, worin das oberste Treppensegment (3) drehbar mit dem Rahmen (1) mittels einem Scharniermechanismus verbunden ist, indem die sonstige Treppensegmente im geschlossenen Zustand der Treppen im besagten Rahmen (1) positioniert werden, worin innerhalb des Rahmens (1) eine verschiebbare Stufe (4, 6) positioniert wird, drehbar mit der inneren Oberfläche der Wand des Rahmens (1) verbunden, worin die geometrische Achse des Längsbalkens des obersten Segments (3) der Treppe zu deren Verwendung entfaltet, kreuzt die oberste Fläche der Lauffläche (41, 62) der verschiebbaren Stufe (4, 6) in der Nähe der Laufflächenmitte (41, 62), damit gekennzeichnet, dass das höchste Treppensegment (3) an einer Abdeckung (2) befestigt wird, die besagtes Rahmen (1) am seinem Unterseite im geschlossenem Zustand der Treppe schließt, dass die verschiebbare Stufe (4, 6) mit mindestens einem Stützelement unterstützt wird, das mit der Abdeckung (2) verbunden wird, ferner dadurch gekennzeichnet, dass
entweder

(i) besagtes Stützelement der verschiebbaren Stufe (4, 6) das oberste Treppensegment (3) ist, worin die verschiebbare Stufe (4) von gelenkigen Verbindern (5) Unterstufe werden, koppeln das oberste Treppensegment (3) und vorzugsweise Längsbalken dieses Segments (3) mit der verschiebbaren Stufe (4), worin im geöffnetem Zustand der Treppe die gelenkige Verbindern (5) im wesentlichem mit den Längsbalken des obersten Treppensegmentes (3) ausgerichtet werden;
oder

(ii) besagtes Stützelement der verschiebbaren Stufe (4, 6) das oberste Treppensegment (3) ist, worin die verschiebbare Stufe (6) mit Stützbeinen (61) verseht ist, die am Lauffläche (62) der Stufe (6) befestigt werden, worin in dem geöffneten Zustand der Treppe die Stützbeine (61) im wesentlichem mit den Längsbalken des obersten Treppensegmentes (3) ausgerichtet werden und vorder-obere Oberfläche der Längsbalken anstoßen; oder

(iii) besagtes Stützelement der verschiebbaren Stufe ist mindestens eine Halterung, an der Abdeckung befestigt, worin die verschiebbare Stufe von gelenkigen Verbindern besagter mindestens einen Halterung unterstützt wird, die an der Abdeckung mit verschiebbaren Stufe befestigt wird, worin im geöffnetem Zustand der Treppe die gelenkige Verbindern parallel zu Längsbalken des obersten Segments der Treppe ausgerichtet werden.

2. Die Klapptreppe nach Anspruch 1, damit gekennzeichnet, dass die Entfernung zwischen der Laufflächenmitte der verschiebbaren Stufe (4, 6) und der Laufflächenmitte der obersten Stufe (31) des obersten Segments (3) der Treppe im Wesentlichen der Treppensteigung entspricht.

3. Die Klapptreppe nach einem der vorhergehenden Ansprüche, worin die Treppe mit einem Mechanismus verseht ist, welches das Hochklappen der gefalteten Treppe zum geschlossenen Zustand der Treppe unterstützt und mindestens teilweise das Gewicht der ausgeklappten Treppe aufwiegt.

4. Die Klapptreppe nach Anspruch 3, worin das Mechanismus, das das Hochklappen unterstützt, ein Federmechanismus ist.

5. Die Klapptreppe nach einem der vorhergehenden Ansprüche, worin die Treppe mit einer Zugstange verseht ist, die ihre Öffnungsbegrenzungen beschränkt.

Revendications

1. Escalier pliable encastré dans un cadre (1), notamment dans un cadre profond ayant une hauteur de paroi accrue, comprenant des segments d'escalier mobiles les uns par rapport aux autres, dans lequel le segment d'escalier le plus haut (3) est relié en rotation au cadre (1) au moyen d'un mécanisme à charnière tandis que les segments d'escalier restants sont positionnés à l'intérieur dudit cadre (1) à l'état fermé d'escalier, dans lequel, à l'intérieur du cadre (1) une marche mobile (4, 6) est positionnée, reliée de manière pivotante à la surface interne de la paroi du cadre (1) dans lequel l'axe géométrique des longerons du segment le plus haut (3) de l'escalier, déplié pour son utilisation, croise la surface supérieure du giron (41, 62) de la marche mobile (4, 6) à proximité du centre de la largeur du giron (41, 62), caractérisé en ce que le segment d'escalier le plus haut (3) est fixé à un couvercle (2) qui ferme ledit cadre (1) au bas de celui-ci à l'état fermé de l'escalier, en ce que la marche mobile (4, 6) est supportée par au moins un élément de support relié au couvercle (2), caractérisé en outre en ce que
chaque

(i) ledit élément de support de la marche mobile (4, 6) est le segment d'escalier supérieur (3), dans lequel la marche mobile (4) est supportée par des connecteurs articulés (5) couplant le segment d'escalier le plus haut (3) et de préférence les longerons de ce segment (3) avec la marche mobile (4), les connecteurs articulés (5) étant, à l'état ouvert de l'escalier, sensiblement alignés avec les longerons du segment d'escalier le plus haut (3);
ou

(ii) ledit élément de support de la marche mobile (4, 6) est le segment d'escalier le plus haut (3), dans lequel la marche mobile (6) est pourvue de pieds de support (61) fixés au giron (62) de la marche (6), dans lequel, à l'état ouvert de l'escalier, les pieds de support (61) sont sensiblement alignés avec les longerons du segment le plus haut (3) de l'escalier et s'appuient sur les surfaces supérieures avant des longerons;
ou

(iii) ledit élément de support de la marche mobile est au moins un support fixé au couvercle, dans lequel la marche mobile est supportée par des connecteurs articulés couplant ledit au moins un support fixé au couvercle avec la marche mobile, dans lequel, à l'état ouvert de l'escalier, les connecteurs articulés sont orientés parallèlement aux longerons du segment le plus haut de l'escalier.

2. L'escalier pliable selon la revendication 1, caractérisé en ce que la distance entre le giron de la marche mobile (4, 6) et le giron de la marche la plus haute (31) du segment le plus haut (3) de l'escalier correspond sensiblement à un pas de marche de l'escalier.

3. L'escalier pliable selon l'une quelconque des revendications précédentes, dans lequel l'escalier est pourvu d'un mécanisme qui supporte le levage de l'escalier plié à l'état fermé de l'escalier et contrebalance au moins partiellement le poids de l'escalier lors de son ouverture.

4. L'escalier pliable selon la revendication 3, dans lequel le mécanisme qui supporte le levage est un mécanisme à ressort.

5. L'escalier pliable selon l'une quelconque des revendications précédentes, dans lequel l'escalier est pourvu d'un agencement de tirants qui limite les limites d'ouverture de l'escalier.

Drawing