METAL SHEET BASE PANEL FOR USE IN ELEVATORS

Description

Technical field

[0001] The present invention relates to a sheet metal base panel for use in elevators. The present invention generally belongs to the field of elevators, specifically to the field of construction of elevator doors and cars and more specifically relates to the field of sheet metal base panels used in elevator doors and cars.Background art

[0002] In the elevator industry, base panels made of sheet metals are commonly used in landing doors, car doors and the car itself.

[0003] Conventionally, elevator doors (landing doors and car doors) are made up of the following components - a bottom header, a top header, a base panel and stiffener. The base panels are always made of sheet metal of uniform thickness throughout the panel. The thickness of the sheet metal is decided based on the strength needed at the weakest point of the panel when subjected to mechanical tests as specified by the standards. Thus the default thickness of the sheet at the weakest point becomes the thickness of the entire panel. Usually, such elevator door or car panels have base panel thickness of 0.8 mm and above. The elevator cars, also called cabins, are constructed with a steel framework for durability and strength, and are made up of a ceiling, platform and base panels. The sides of the elevator cars are also usually made from steel sheet and are trimmed on the inside with panelling. In elevator cars, the base panels connect the ceiling and the platform.

[0004] Chinese Patent Application CN 109455608 A discloses an integrated elevator door panel structure wherein the left and right ends of the panel body are respectively provided with left and right flanges. The upper and lower ends of the panel are respectively provided with upper and lower flanges. The inner side wall of the hemming is provided with curling, the inner side of the curling is provided with a connecting piece, and the bottom of the connecting piece is provided with a guide shoe under the lower hemming; there is an installation cavity, and the installation cavity is provided with reinforcing ribs fixed on the surface of the board. The said patent document claims that such panel structure has the characteristics of being able to effectively increase the production efficiency and improve the overall strength of the door panel.

[0005] Chinese Patent Application CN 205873639 U discloses a one-piece bending type elevator door which includes a door panel main body, an upper head, a lower head, and a door slider mounted on the said lower head. In the main body of the said elevator door, the sides (left and right sides) are bent in an inverted U-shape to form a package structure. The U-shaped inverted portion of the door panel body is bent to form the upper head and the lower side is formed in a stepped inversion to form the lower head, and the stepped portion includes at least one vertical surface, with the door slider mounted on the vertical surface. The stepped shape described in this example is a secondary step shape comprising a first stage step connected directly to the door panel body and a second stage step connected to the first stage step end, the door slider being mounted on the vertical plane of the first step. The patent document discloses that the door is made of one-piece moulding, thereby reducing the door production process and making the process simple and easy to achieve and also reduces the cost of the elevator car door.

[0006] Chinese Patent Application CN 205061300 U discloses an elevator door with a new integrated structure, including a main door with a door body which includes a side folding on the left and right sides, an upper and a lower hemming, wherein the lower hem is provided with mounting holes for mounting a door slide, the said lower hem also folded edge wise through a first and second bending edge, and a bending on the third side and fourth side, thereby forming four stepped off side, wherein the lower end of the vertical flanges of the rim includes a lower hem with a vertical mounting plate, wherein the vertical mounting plate is bent through the first side and the second side of the bend is bent twice in L-shaped manner, the vertical position corresponding to the lower hem of the mounting plate. The mounting hole is located in the vertical mounting plate, wherein the first folded edge and second folded edge between the first and three folding edges, grooves are formed for installation of slider between the edges of the fourth bend. The said novel feature, especially of the lower hem through elevator door plant lower part which adopts the quartic bending, is proposed to not only reduce the manufacturing procedure of the door plant, but has also guaranteed the rigidity of the door plant and claimed to make the installation of the door slider convenient.

[0007] Document WO 2023 / 037171 A1 discloses a sheet metal base panel for use in elevators wherein the base panel is made from sheet metal of low thickness without compromising its structural integrity, by a specialised hemming process. The base panel is constructed from a single sheet of metal and incorporates the top and bottom header to form a unitary component. The construction is such that the headers can be positioned either way and hence possesses rotational symmetry which enables in easier installation. This is achieved by a special bending of the base panel on all edges of both the top side and bottom side, four times - a first 90° bending followed by a second 90° bending, a third 90° bending and a fourth 180° hemming of the open edge formed after the third 90° bending. Document WO 2006 / 027410 A2 discloses a sheet metal base panel according to the preamble of claim 1.

[0008] However, the above said inventions do not completely address the problems in the prior art, particularly, they do not provide an effective mechanism to reduce the thickness requirement of the sheet metal base panels used in elevator landing & car doors and the cars itself, without compromising on the structural integrity of said panels. The patents disclosed in the prior art documents are also not installation friendly as the holes to fix the base panel are not symmetrical. Therefore, there is a need in the art to provide a sheet metal base panel for use in elevators which is structurally simpler but still able to pass all the integrity and resistance tests for the commercialization to the market.

[0009] The information disclosed in this background of disclosure section is only for enhancement of understanding of the general background of the invention and should not be taken as acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

[0010] Further it will be apparent to those skilled in the art that the objects of this invention have been achieved by providing a sheet metal base panel for use in elevators, which is unique in nature unlike existing systems or the ones described in the above prior art in the field known to the inventors. Various changes may be made in and without departing from the scope of the invention, as defined by the appended claims. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention.

[0011] Therefore, the scope of the invention is to be determined by the claims.Disclosure of the invention

[0012] In this context, the technical task underlying the present invention is to propose a sheet metal base panel for use in elevators, which overcomes the drawbacks in the prior art as described above.

[0013] In particular, an object of the present invention is to provide a sheet metal base panel for use in elevators, which is simpler with respect to prior art solutions, but still able to meet the strength and resistance requirements for the elevator door to be safe to use.

[0014] The stated technical task and specified objects are substantially achieved by a sheet metal base panel for use in elevators, comprising a single main body developing from a top side to a bottom side according to a longitudinal direction and from a left side to a right side according to a transverse direction. The single main body has a front side and a rear side. The edges of both the top side and bottom side and of both the left side and right side are bended, as a reinforcement, backwards and inwards so as to define for each side an inner recess developing along the corresponding side.

[0015] The sheet metal base panel comprises: at least one stiffener of a first type developing according to a direction substantially parallel to the longitudinal direction and attached to a middle area of the rear side of said main body; at least two stiffeners of a second type developing according to a direction substantially parallel to the longitudinal direction, said stiffeners of the second type being at least partly arranged in the inner recesses respectively of the left side and right side; at least one stiffener of a third type developing according to a direction substantially parallel to the transverse direction, said stiffener of the third type (30) being at least partly arranged in the inner recess of the top side.

[0016] According to one embodiment, the edge of the bottom side comprises a hemming so as to define an overlapping portion acting as a reinforcement. Preferably, the edge of the bottom side comprises a first 90° bending followed by a second 90° bending which forms an open edge, said open edge having a 180° hemming so as to define an overlapping portion.

[0017] According to one embodiment, the edge of these sides comprises a backward portion which originates from the main body and develops away from it on the rear side and an inward portion which originates from the backward portion and develops along the rear side, at a distance from it.

[0018] Preferably, the overlapping portion extends for the entirety of the inward portion and for at least a part of the backward portion.

[0019] According to one embodiment, the stiffener of the first type comprises two contacting portions attached to the rear side and interspersed by a protruding portion.

[0020] Preferably, the protruding portion has a trapezoid-like cross section.

[0021] According to one embodiment, the stiffener of the second type is shaped and arranged so as to abut on both the bended edge of the respective side and the rear side of the main body.

[0022] According to one embodiment, the stiffener of the second type is shaped and arranged so as to cover the inner recess of the corresponding left side or right side.

[0023] Preferably, the stiffener of the second type has a cross section which develops according to rectangular-like open broken line.

[0024] Preferably, the stiffener of the second type is given a first 90° bending followed by a second 90° bending and a subsequent third 90° bending which forms an open edge that is subsequently hemmed by 180°.

[0025] Preferably, the thickness of said at least one stiffener of the third type is greater than the thickness of the main body.

[0026] Preferably, stiffener of the third type has a U-shaped cross section. According to one embodiment, the stiffener of the third type is entirely enclosed in the inner recess of the top side.Brief description of drawings

[0027] Additional features and advantages of the present invention will become more apparent from the non-limiting, description of a preferred, but non-exclusive embodiment of a sheet metal base panel for use in elevators, as illustrated in the appended drawings, in which: figures 1a and 1b illustrate a sheet metal base panel for use in elevators, according to the present invention, respectively in a front and lateral views; figure 2 illustrates a cross section of the sheet metal base panel of figure 1a; figure 3 illustrates one embodiment of a stiffener of a second type; figure 4 illustrates one embodiment of a stiffener of a third type, arranged inside the top side of the sheet metal base panel of figure 1a; figure 5 illustrates a side view of the top and bottom sides of the sheet metal base panel of figure 1a. Detailed description of preferred embodiments of the invention

[0028] With reference to the figures, number 1 indicates a sheet metal base panel for use in elevators. In particular, the base panel 1 is the core part of a door leaf of an elevator door (for example, the car door).

[0029] The base panel 1 comprises a single main body 2. The main body 2 develops from a top side 2a to a bottom 2b according to a longitudinal direction and from a left side 2c to a right side 2d according to a transverse direction. In other words, the main body 2 is substantially planar, that is to say bidimensional. The third dimension (usually called thickness) is negligible with respect to the other two dimensions.

[0030] The main body has a front side 2e and a rear side 2f.

[0031] In particular, the bottom side 2b is preferably provided with a pair of holes symmetric to each other, which, in combination with a bracket and a hoe fixed to the main body at the pair of holes, form the bottom header.

[0032] The edges 3 of both the top side 2a and bottom side 2b and of both the left side 2c and right side 2d are bended backwards and inwards so as to define for each side an inner recess 4 developing along the corresponding side 2a, 2b, 2c, 2d. In particular, the bending acts as a reinforcement.

[0033] In particular, the edge 3 of these sides comprises a backward portion 3a which originates from the main body 2 and develops away from it on the rear side 2f. The edge 3 comprises also an inward portion 3b which originates from the backward portion 3 and develops along the rear side 2f, at a distance from it. In other words, the edge 3 comprises a U-shaped inversion.

[0034] In this case, the inner recess 4 is the space between the main body 2, the backward portion 3a and the inward portion 3b. The inner recess 4 is open on one side (the one facing towards the inside of the main body 2).

[0035] According to the illustrated embodiment, the edges 3 are given a first 90° bending followed by a second 90° bending which forms an open edge.

[0036] Preferably, the edge 3 of the bottom side 2b comprises a 180° hemming so as to define an overlapping portion acting as a reinforcement.

[0037] According to a preferred embodiment, illustrated in figure 5, the edge 3 of the bottom side 2b comprises a first 90° bending 3' followed by a second 90° bending 3" which forms an open edge. The open edge has a 180° hemming 3‴ so as to define an overlapping portion.

[0038] Please note that the bendings and hemmings to which we are referring to in the application are "subsequent" in the sense that they are one after the other in order or place.

[0039] Operatively, the bottom edge 3 is formed with these procedural steps: making a first 180° hemming (3‴); making a second 90° bending (3") following the first 180° hemming (3‴); making a third 90° bending (3') following the second 90° bending (3").

[0040] In particular, the overlapping occurs for the entirety of the inward portion 3b and for at least a part of the backward portion 3a.

[0041] More preferably, the manufacturing of the base panel 1 occurs like the following: a) bending the bottom edge (3) with these procedural steps: making a first 180° hemming (3‴); making a second 90° bending (3") following the first 180° hemming (3‴); making a third 90° bending (3') following the second 90° bending (3"); b) bending the top edge (3) with these procedural steps: making a fourth 90° bending (3"") following the third 90° bending (3"'); making a fifth 90° bending (3""') following the fourth 90° bending (3"").

[0042] The base panel 1 comprises at least one stiffener of a first type 10. The stiffener of a first type 10 develops according to a direction substantially parallel to the longitudinal direction (in a mounted state of the base panel 1, vertical direction). The stiffener of a first type 10 is attached to a middle area of rear side 2f of the main body 2.

[0043] Preferably, the stiffener of the first type 10 comprises two contacting portions 11 attached to the rear side 2f. The two contacting portions 11 are interspersed by a protruding portion 12. In other words, the protruding portion 12 connects the two contacting portions 11.

[0044] The protruding portion 12, starting from the contacting portion 11, develops away from the rear side 2f.

[0045] According to a preferred embodiment, illustrated in figure 2, the protruding portion 12 has a trapezoid-like cross section. Preferably, the protruding portion 12 does not protrude beyond an imaginary plane surface defined by the bended edges 3 of the left side 2c and right side 2d.

[0046] The base panel 1 comprises at least two stiffeners of a second type 20. The stiffener of a second type 20 develops according to a direction substantially parallel to the longitudinal direction (in a mounted state of the base panel 1, vertical direction). The stiffeners of the second type 20 are at least partly arranged in the inner recesses 4, respectively of the left side 2c and right side 2d.

[0047] Preferably, the stiffener of the second type 20 is shaped and arranged so as to abut on both the bended edge 3 of the respective side 2c, 2d and the rear side 2f of the main body 2. In particular, the stiffener of the second type 20 abuts on the inward portion 3b of the respective side 2c, 2d.

[0048] For "abut on" here is intended that the element is in contact and rests on the other one.

[0049] Preferably, the stiffener of the second type 20 has a cross section which develops according to rectangular-like open broken line.

[0050] According to a preferred embodiment, illustrated in figure 3, the stiffener of the second type 20 is given a first 90° bending 20a followed by a second 90° bending 20b and a subsequent third 90° bending 20c which forms an open edge that is subsequently hemmed by 180° 20d.

[0051] Therefore, a first open edge 21a is connect via the first 90° bending 20a to a first intermediate portion 21b, in turn connected to a second intermediate portion 21c by a second 90° bending 20b, in turn connected to a second open edge 21d by a third 90° bending 20c. The second open edge 21d has 180° hemming so as to define an overlapping portion.

[0052] In this embodiment, the first open edge 21a abuts on the inward portion 3b of the bended edge 3 of the respective side 2c, 2d. The second intermediate portion 21c abuts on the rear side 2f of the main body 2.

[0053] Preferably, the stiffener of the second type 20 is shaped and arranged so as to cover the inner recess 4 of the corresponding left side 2c or right side 2d. In particular, the stiffener of the second type 20 covers the open side of the inner recess 4.

[0054] The base panel 1 comprises at least one stiffener of a third type 30. The stiffener of a third type 30 develops according to a direction substantially parallel to the transverse direction (in a mounted state of the base panel 1, horizontal direction). The stiffener of the third type 30 is at least partly arranged in the inner recess 4 of the top side 2a.

[0055] According to a preferred embodiment, illustrated in figure 4 or 5, the stiffener of the third type 30 has a U-shaped cross section. Preferably, the stiffener of the third type 30 is attached to the top side 2a, in particular to the backward portion 3a. Preferably, the stiffener of the third type 30 is attached to the top side 2a faced downward. Preferably, the stiffener of the third type 30 is entirely enclosed in the inner recess 4 of the top side 2a.

[0056] Preferably, the thickness of the stiffener of the third type 30 is greater than the thickness of the main body 2. Preferably, the main body 2 has thickness equal or less than 1 mm. Preferably, the stiffener of the third type 30 has thickness of at maximum 3 mm.

[0057] According to a preferred embodiment, the stiffener of the third type 30 comprises a sheet comprising a first 90° bending 30a followed by a second 90° bending 30b.

[0058] In particular, the preferred and illustrated embodiment envisages the use of: a stiffener of a first type 10 having two contacting portions 11 attached to the rear side 2f and interspersed by a protruding portion 12 having a trapezoid-like cross section; two stiffeners of the second type 20 having a cross section which develops according to rectangular-like open broken line. a stiffener of the third type 30 having a U-shaped cross section.

[0059] This arrangement of stiffeners 10, 20, 30 in combination with the bended edges 3, in particular the overlapping hemmed edge 3 of the bottom side 2b ensures high stability, integrity and strength (i.e. safety) while having reduced thickness with respect to the prior art.

[0060] Preferably, the mentioned components are made of stainless steel.

[0061] The characteristics of a sheet metal base panel for use in elevators, according to the present invention, emerge clearly from the above description, as do the advantages.

[0062] In particular, the presence of the three types of stiffeners and the specific arrangement proposed allows to produce a base panel with structural rigidity while being simpler and less thick than the previous solution.

[0063] In addition, the combination of the bended edges and the stiffeners enhances this result.

[0064] In addition, the preferred embodiment of the present invention involves the use of welding free technology, such as bending of sheets and fixation by means of riveting or gluing. However, the present invention still envisages the possibility of resorting to the use of welding.

[0065] Preferably, pre-painted sheet is used for manufacturing the proposed door panel leaf, so powder coating process is not necessary. However, the present invention still envisages the possibility of resorting to the use of powder coating process.

[0066] In addition, the proposed sheet metal base panel has excellent fire rating. Moreover, the proposed base panel is light weight and easy to handle during installation.

Claims

1. A sheet metal base panel (1) for use in elevators, comprising a single main body (2) developing from a top side (2a) to a bottom side (2b) according to a longitudinal direction and from a left side (2c) to a right side (2d) according to a transverse direction, said single main body (2) having a front side (2e) and a rear side (2f); wherein edges (3) of both the top side (2a) and bottom side (2b) and of both the left side (2c) and right side (2d) are bended, as a reinforcement, backwards and inwards so as to define for each side an inner recess (4) developing along the corresponding side (2a, 2b, 2c, 2d); at least one stiffener of a first type (10) developing according to a direction substantially parallel to the longitudinal direction and attached to a middle area of the rear side (2f) of said main body (2), characterized in that said sheet metal base panel (1) comprises: at least two stiffeners of a second type (20) developing according to a direction substantially parallel to the longitudinal direction, said stiffeners of the second type (20) being at least partly arranged in the inner recesses (4) respectively of the left side (2c) and right side (2d); at least one stiffener of a third type (30) developing according to a direction substantially parallel to the transverse direction, said stiffener of the third type (30) being at least partly arranged in the inner recess (4) of the top side (2a).

2. The sheet metal base panel (1) according to claim 1, wherein the edge (3) of the bottom side (2b) comprises a hemming so as to define an overlapping portion acting as a reinforcement.

3. The sheet metal base panel (1) according to claim 1 or 2, wherein the edge (3) of the bottom side (2b) comprises a first 90° bending followed by a second 90° bending which forms an open edge, said open edge having a 180° hemming so as to define an overlapping portion.

4. The sheet metal base panel (1) according to any one of the preceding claims, wherein the edge (3) of these sides (2a, 2b, 2c, 2d) comprises a backward portion (3a) which originates from the main body (2) and develops away from it on the rear side (2f) and an inward portion (3b) which originates from the backward portion (3) and develops along the rear side (2f), at a distance from it.

5. The sheet metal base panel (1) according to claim 4 when depending on claim 2 or 3, wherein the overlapping portion extends for the entirety of the inward portion (3b) and for at least a part of the backward portion (3a).

6. The sheet metal base panel (1) according to any one of the preceding claims, wherein said at least one stiffener of the first type (10) comprises two contacting portions (11) attached to the rear side (2f) and interspersed by a protruding portion (12).

7. The sheet metal base panel (1) according to claim 6, wherein the protruding portion (12) has a trapezoid-like cross section.

8. The sheet metal base panel (1) according to any one of the preceding claims, wherein the stiffener of the second type (20) is shaped and arranged so as to abut on both the bended edge (3) of the respective side (2c, 2d) and the rear side (2f) of the main body (2).

9. The sheet metal base panel (1) according to any one of the preceding claims, wherein the stiffener of the second type (20) is shaped and arranged so as to cover the inner recess (4) of the corresponding left side (2c) or right side (2d).

10. The sheet metal base panel (1) according to any one of the preceding claims, wherein the stiffener of the second type (20) has a cross section which develops according to rectangular-like open broken line.

11. The sheet metal base panel (1) according to any one of the preceding claims, wherein the stiffener of the second type (20) is given a first 90° bending (20a) followed by a second 90° bending (20b) and a subsequent third 90° bending (20c) which forms an open edge that is subsequently hemmed by 180° (20d).

12. The sheet metal base panel (1) according to any one of the preceding claims, wherein the thickness of said at least one stiffener of the third type (30) is greater than the thickness of the main body (2).

13. The sheet metal base panel (1) according to any one of the preceding claims, wherein said at least one stiffener of the third type (30) has a U-shaped cross section.

14. The sheet metal base panel (1) according to any one of the preceding claims, wherein the stiffener of the third type (30) is entirely enclosed in the inner recess (4) of the top side (2a).

15. An elevator comprising a sheet metal base panel (1) according to any one of the preceding claims.