Universal landing for spiral staircases

Abstract

 The universal landing (7) for spiral staircases (1), of the type which has a helical shape and a circular plan formed around a central core (3) and which passes at its top through a passage hole (5) formed in the floor, has a region (11) which protrudes frontally from a tread region (9) extending from the central core. The protruding region is suitable to be superimposed and secured onto the landing surface of the floor at the staircase passage hole.

Description

[0001] The present invention relates to a universal landing for spiral staircases.

[0002] Spiral staircases are currently known which extend so as to form a helix having a circular plan, without central well, and are provided with steps having a triangular tread. At their top, spiral staircases pass through an appropriate hole formed in the floor and have a landing fixable to said floor at the landing surface.

[0003] The staircase passage hole formed in the floor can have various shapes, in particular circular or square shapes, and can have different dimensions according to the constructive requirements. The landing of the spiral staircase is therefore built so that it matches the dimensions of said passage hole or must be fitted with additional elements allowing it to adapt to the shape and dimensions of said hole.

[0004] This obviously increases considerably the cost of the staircase. Complexity of the landing assembly is furthermore often noted negatively.

[0005] A principal object of the present invention is to solve the above described problem by providing a landing for spiral staircases for universal use with respect to the shape and dimensions of the staircase passage hole formed in the floor.

[0006] Within the scope of this object, another object of the present invention is to provide a landing for spiral staircases which is conceptually simple, easy to assemble and safely reliable in use.

[0007] With these and other objects in view, there is provided, according to the invention, a universal landing for spiral staircases of the type which is provided with a helical shape and a circular plan formed around a central core and which passes at its top through a passage hole formed in the floor, said landing being characterized in that it has a region protruding frontally from a tread region which extends from said central core, said protruding region being suitable to be superimposed and secured on the landing surface of said floor at said staircase passage hole.

[0008] Further features and advantages of the invention will become apparent from the following detailed description of a preferred embodiment of the universal landing for spiral staircases, illustrated only by way of non-limitative example in the accompanying drawings, wherein:

figure 1 is a schematic plan view of a spiral staircase provided with the landing according to the invention;

figure 2 is a partially sectional side view of the landing, taken along a median longitudinal plane;

figure 3 is a partial bottom view of said landing;

figure 4 is a corresponding front view thereof;

figure 5 is a longitudinal sectional view of a device for securing the landing to the landing surface of the floor;

figure 6 is a sectional view, taken along the plane VI-VI of figure 5;

figure 7 is a partial longitudinal sectional view of a different embodiment of the securing device;

figure 8 is a sectional view, taken along the plane VIII-VIII of figure 7;

figure 9 is a perspective view of a hinge element of the securing device shown in figure 7;

figure 10 is a transverse sectional view of a further embodiment of the securing device;

figure 11 is a longitudinal sectional view of another embodiment of the securing device;

figure 12 is a sectional view, taken along the plane XII-XII of figure 11.

[0009] With particular reference to the above figures, the reference numeral 1 generally designates the spiral staircase which, in a substantially known manner, has a plurality of steps 2 having a triangular tread and extending along a helix with a circular plan around a central core 3. The external profile of the steps 2 is rounded so as to form a circular arc, and the steps are peripherally provided with bushes 4 for engaging the uprights supporting the banister of the staircase.

[0010] At its top, the spiral staircase passes through a passage hole 5 formed in the floor 6 and is provided with a landing 7 which is rigidly coupleable to the landing surface 8 of said floor 6. The steps 2 and the landing 7 are preferably obtained from folded metal plates.

[0011] The landing 7 has a tread region 9 shaped so that it substantially has the same triangular profile as the steps 2, starting from a vertex constituted by a sleeve 10 being part of the core 3 of the staircase.

[0012] A protruding region 11 extends from the tread region 9 and is suitable to be superimposed, in assembled position, on the landing surface 8 of the floor 6, at the passage hole 5. The external profile of said protruding region 11 is rectangular with appropriately chamfered outer corners, and its longer side is transverse to the median axis of the tread region 9.

[0013] The tread region 9 is provided, in an upward portion, with a recess 12 for containing a layer of sound-deadening material and, along its lateral edges, with borders 13 folded downward and decreasing in height from the central region toward the outward region of the landing. The region 9 is furthermore stiffened in a downward portion by radial ridges 14 and front ridges 15 and is provided, at its outward edge, with a bush 16 for engaging a related upright for supporting the banister of the staircase.

[0014] The protruding region 11 has two curvatures: one is in a radial direction and the other one is along a plane vertically transverse to the longitudinal plane. More precisely, the protruding region 11 is curved downward in a radial direction and is curved on a transverse plane so that it forms an arc with its concavity directed downwardly. In practice, the outer corners of said region 11 are symmetrical at a lower level than the other parts.

[0015] The protruding region 11 is to be secured onto the landing surface 8 of the floor 6 by means of a device 17 mounted below the landing, as shown in detail in figures 5 and 6. Actually, the landing is provided with a pair of these securing devices, which are arranged symmetrically at the opposite sides of the tread region 9.

[0016] Each securing device 17 is provided with an L-shaped element 18 obtained from a profiled element having a C-shaped cross-section; its arms, in assembled position, are respectively radial to the landing and vertically adjacent to the passage hole 5. The L-shaped element 18 is fixed by means of a screw element 19 to a support 20, in practice a bracket, oscillating in a plane which is radial with respect to the landing; the support 20 is articulated, by means of a pair of coaxial pivots 21, to a fork 22 fixed below the tread region 9 of the landing, substantially at the edge of the protruding region 11.

[0017] The L-shaped element 18 has, on its vertical arm, a slot 23 which is crossed by an expansion bolt 24 protruding from the floor 6 so as to support an abutment block 25; a pre-loading screw 26 is suitable to act on said abutment 25 along a vertical axis and is screwed in a nut 27 which is fixed inside the L-shaped element 18.

[0018] Therefore, by tightening the pre-loading screw 26 it is possible to move the L-shaped element 18 with respect to the abutment 25, which is fixed to the floor 6; since the L-shaped element 18 is rigidly coupled to the landing 7, the protruding region 11 is thus secured onto the landing surface 8 (see figure 5 for the sake of clarity). The double curvature of the protruding region 11 ensures perfect mating of the landing 7 to the surface 8, starting from the lowered outer corners of said region 11.

[0019] As shown schematically in figure 1, the protruding region 11 of the landing 7 overlaps different portions of the landing surface 8 according to the shape and dimensions of the staircase passage hole 5. In particular, the reference numerals 5a, 5b designate the outline of a circular hole having maximum and minimum dimensions and the reference numerals 5c, 5d designate the outline of a square hole which equally has maximum and minimum dimensions. Naturally, the larger holes 5a, 5c are tangent to a circumference concentric to the axis of the core 3 of the landing proximate to the outer edge of the region 11, at the median axis of said landing, whereas the minimum-size holes 5b, 5d are practically tangent to the tread region 9.

[0020] The described landing thus has universal application, since it can be applied without additional elements to staircase passage holes having different shapes and dimensions. The oscillating fitting of the L-shaped securing element 18 furthermore allows to compensate for any discrepancy in the verticality of the passage hole.

[0021] Figures 7, 8 and 9 illustrate a different embodiment of the securing device, wherein the L-shaped element 18 is oscillatably supported by means of a hinge element generally designated by the reference numeral 28. Said hinge element 28 has a pair of jaws 29 and 30 between which a support 31, fixed below the landing, is to be secured. The jaws 29 and 30 have a semicylindrical shape which is in particular such as to reconstitute, after securing against the support 31, a cylindrical surface the axis whereof is horizontally transverse to the L-shaped element 18.

[0022] The jaws 29 and 30 have respective transverse holes 32 and 33 through which a screw 34 for locking the L-shaped element 18 passes; said L-shaped element 18 rests against the cylindrical surface of the jaw 29 and engages a prism-shaped central expansion 29a of said jaw. The head 34a of the locking screw 34 acts on a spacer 35 which has a face 35a recessed so as to form a cylindrical surface which is complementary to the surface of the jaw 30.

[0023] Accordingly, the L-shaped element 18 can rotate through an angle about the hinge element 28 during the securing of the landing, thus compensating for any error in the verticality of the staircase passage hole.

[0024] Figure 10 illustrates a simplified embodiment of the securing device, wherein the L-shaped element 18 is rigidly locked onto the support 31, which is fixed below the landing, and thus cannot oscillate.

[0025] Figures 11 and 12 illustrate another embodiment of the securing device, wherein the L-shaped element 18 is rigidly coupled to the landing 7 by means of a traction element 36. Said traction element 36 is provided with an eyelet 37 engageable by a bolt 38 which passes through a corresponding hole formed in the radial ridge 14 and is to be locked by a related nut 39 by interposing safety washers 40 which are appropriately provided with teeth.

[0026] The traction element 36 has a threaded stem 36a on which a nut 41 and a lock nut 42 screw for securing the L-shaped element 18, which is crossed by said stem 36a at a slot 43 formed longitudinally with respect to the horizontal arm of said L-shaped element 18.

[0027] In practice, the traction element 36 is rigidly coupled to the landing 7 without tightening the bolt 38 fully, in order to allow said bolt to act as a pivot for the oscillation of the L-shaped element 18 prior to fixing to the floor 6. Equally, the traction element 36 is rigidly coupled to the L-shaped element 18 without mutually tightening the nuts 41 and 42; the stem 36a of the traction element 36 is inserted in the slot 43 so that it protrudes downward as little as possible. Assembly thus performed allows to orientate the L-shaped element 18 in the required manner, so that it adapts to both circular and square passage holes 5.

[0028] The L-shaped element 18 is fixed to the floor 6 by means of the expansion bolt 24. By acting on the lower nut 41 of the traction element 36, the landing 7 is then subjected to downward traction, so as to secure the protruding region 11 onto the landing surface 8, thus obtaining perfect mating. Finally, the final tightening of the bolt 38 is achieved by means of the nut 39 and of the lock nut 42.

[0029] The landing according to the invention optimally achieves the intended aim, since it is rigidly coupleable to holes for the passage of the spiral staircase which have different shapes and dimensions. Assembly of the landing is furthermore easy and quick, and for this purpose it is sufficient to act only on the securing device.

[0030] In the practical embodiment of the invention, the materials employed, as well as the shape and dimensions, may be any according to the requirements.

[0031] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs.

Claims

1. Universal landing (7) for spiral staircases (1) of the type which is provided with a helical shape and a circular plan around a central core (3) and which passes at its top through a passage hole (5) formed in the floor (6), characterized in that it has a region (11) protruding frontally from a tread region (9) which extends from said central core, said protruding region being suitable to be superimposed and secured onto the landing surface of said floor, at said staircase passage hole.

2. Landing according to claim 1, characterized in that said protruding region has two curvatures, namely one in a radial direction and one along a plane which is vertically transverse to the longitudinal plane.

3. Landing according to claim 2, characterized in that said protruding region is curved downward in a radial direction and is curved on a transverse plane so as to form an arc with its concavity directed downwardly, the outer corners of said protruding region being symmetrical at a lower level than the other parts.

4. Landing according to claim 1, characterized in that said protruding region is securable onto said landing surface of the floor by means of a securing device mounted below said tread region and provided with an L-shaped element the arms of which, in assembly position, are respectively rigidly coupled radially to said tread region, substantially at the edge of said protruding region, and vertically adjacent to said passage hole; screw means being coupled to said latter arm and being suitable to act, along a vertical axis, on fixed abutment means protruding from said floor.

5. Landing according to claim 4, characterized in that said L-shaped element is fixed to a support which is articulated to a fork fixed below said tread region so that it oscillates on a plane radial to said landing.

6. Landing according to claim 4, characterized in that said L-shaped element is oscillatably supported by means of a hinge element comprising a pair of jaws between which a support is to be secured, said support being fixed below said tread region, said jaws having a semicylindrical shape such as to reconstitute, after securing against said support, a cylindrical surface the axis whereof is horizontally transverse to said L-shaped element.

7. Landing according to claim 1, characterized in that said protruding region is securable onto said landing surface of the floor by means of a securing device mounted below said tread region and provided with an L-shaped element the arms whereof, in assembly position, are respectively rigidly coupled radially with respect to said tread region by means of a traction element suitable to subject said tread region to downward traction, and vertically adjacent to said passage hole.

8. Landing according to claim 7, characterized in that said traction element has an eyelet engageable by screw means for fixing to said tread region, thus allowing said L-shaped element to oscillate on a plane which is radial to said landing.

Drawing