Stool

Abstract

This utility model relates to the furniture industry, specifically to the design of stools intended for sitting. Its primary application is household furniture, furniture for public spaces (cafes, bars), and country furniture, where strength, ease of assembly, and structural stability are essential. The technical result achieved through the use of this utility model consists of increasing the rigidity and stability of the frame while simultaneously reducing the number of parts and simplifying assembly. This technical result is achieved by the stool comprising a seat and a supporting frame including legs. The legs are made of rectangular tubes, each leg being a single L-shaped piece connected to the other legs under the seat in a cross-shaped formation, each leg being connected to its neighbors by two connecting elements. 4 c.p. f.

Description

[0001] This utility model relates to the furniture industry, specifically to the design of stools intended for sitting. Its primary application is household furniture, furniture for public spaces (cafes, bars), and garden furniture, where durability, ease of assembly, and structural stability are important.

[0002] Various stool designs consisting of a seat and a supporting frame with legs are known in the prior art. In particular, a stool covered by utility model patent RU 32669 U1 uses metal legs with a V-shaped cross-section. The legs are attached to the seat via a special metal plate with petals, where each petal is connected to two adjacent legs. A disadvantage of this solution is the complexity of manufacturing the legs from bent sheet metal and the need for a special mounting plate, which increases the number of parts and the labor intensity of assembly. A stool covered by patent RU 2576227 C1 also features flat legs that intersect with each other using a tongue-and-groove joint, with their ends inserted directly into the openings of the seat.This design is intended primarily for wooden elements and does not provide high rigidity when using metal tubular profiles, since fixation occurs only due to wedging in the seat.

[0003] The closest analogue (prototype) to the claimed utility model is the stool disclosed in patent RU 2572440 C1. This known stool comprises a seat and a supporting frame, including legs made of pipes that intersect under the seat and are connected in pairs directly at the points of contact by bolts passing through through holes in the legs. This solution allows for a frame with a cross-shaped leg geometry, but has a number of drawbacks that are addressed in the claimed utility model. The use of round pipes in the prototype complicates the installation of fasteners and reduces the torsional rigidity of the connection compared to rectangular pipes, which have flat edges for secure fixation.

[0004] The objective of the claimed utility model is to simplify the design of the stool, increase its rigidity and assembly efficiency while maintaining compactness in packaged form.

[0005] The technical result achieved by using the utility model is to increase the rigidity and stability of the frame while simplifying assembly.

[0006] The technical result is achieved due to the fact that the stool comprises a seat and a support frame including legs, characterized in that the legs are made of rectangular pipes, each leg has a solid L-shape and with the other legs under the seat forms a cross-shaped configuration, each leg is connected to the lower plane of the seat by means of two fastening threaded elements. The height of the legs (the vertical part of the L-shaped element) is less than 50 cm. 6 The length of the horizontal (under-seat) part of the L-shaped element is less than 23 cm. The horizontal (under-seat) part of the L-shaped leg contains at least two fastening holes. The first hole is located at a distance of 3.5 cm from the edge of the leg, and the second hole is located at a distance of 8.5 cm from the edge of the leg.

[0007] Using rectangular rather than round tubes increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly. A rectangular profile offers greater resistance to bending and torsion relative to its axes, eliminating the need for additional stiffeners, while flat edges simplify the process of fixing and joining elements.

[0008] Making each leg as a single L-shaped piece (instead of assembling a vertical post and a separate crossbar or tsarga) directly leads to increased rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since the monolithic design eliminates weak nodal connections at the transition from the leg to the seat base, and also reduces the overall number of elements required to assemble the product.

[0009] The formation of a cross-shaped configuration between the horizontal parts of the L-shaped legs increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since such a connection creates a closed power system that operates on tension and compression in two directions, which replaces the traditional complex frame of four sides.

[0010] The fixation of each leg to the lower plane of the seat using two connecting fasteners is aimed at increasing the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since this design creates a statically determinate and geometrically unchangeable spatial structure that requires a minimum number of fixing points without losing strength.

[0011] Making the vertical part of the L-shaped element less than 50 cm high helps increase the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since reducing the length of the lever reduces the bending moment acting on the material at the bend of the profile, which allows the use of thinner-walled pipes without losing load-bearing capacity and without installing additional braces.

[0012] Designing the horizontal leg section to be less than 23cm in length increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, as it reduces the cantilever projection on which the seat rests, thereby reducing stress in the corners of the L-shaped elements and eliminating the need for braces or braces to reinforce them.

[0013] Equipping the underseat section of the L-shaped leg with at least two mounting holes increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since the two-point attachment of each branch to the seat or to the central crosspiece prevents the elements from rotating relative to the axis and creates a rigid frame connection without the use of complex shaped overlays.

[0014] The placement of the first hole at a distance of 3.5 cm and the second at a distance of 8.5 cm from the edge of the leg is dictated by the goal of increasing the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, since such an offset relative to the edge and to each other allows for the maximum use of the load-bearing capacity of the material, evenly distributing the load in the connection area and preventing chipping or tearing of the edge of the part during operation.

[0015] The vertical leg height, less than 50 centimeters, was chosen for strength considerations. According to the formula for the bending moment of a cantilever beam, M = F × L, the moment is directly related to the arm length, and limiting the height allows for maintaining stress in the metal within acceptable limits without the use of additional reinforcement. Similarly, the length of the horizontal under-saddle section is limited to less than 23 centimeters, as dictated by the formula for the maximum bending moment for a beam on two supports, M_max = (q × l²) / 8, where the quadratic dependence on the span length means that even a small increase in length causes a sharp increase in the moment, requiring the addition of additional reinforcement.Finally, the placement of the fastening holes at 3.5 and 8.5 centimeters from the edge of the leg has a clear mathematical justification: the first hole is located at the minimum allowable distance from the edge to avoid chipping of the material under the compressive strength condition σ_cm = F / (d × t), while the second hole creates the necessary support base, since the moment tending to rotate the assembly M = F × h is balanced by a couple of forces in the bolts M = N × b, where the increased distance b between the holes reduces the load on each fastener. Thus, it is these calculated values ​​that ensure increased rigidity and stability of the frame while simultaneously reducing the number of parts and simplifying assembly.

[0016] The proposed utility model is a stool, the design of which was developed to achieve the technical result of increasing the rigidity and stability of the frame while reducing the number of parts and simplifying assembly. Below is a detailed description of the manufacturing and assembly of this product, as well as how its design features enable this result to be achieved.

[0017] The production of a stool begins with the preparation of the material. For the supporting frame, rectangular steel or aluminum tubing is used. The choice of this profile is deliberate: its flat edges significantly simplify the assembly and fastening of the elements, and its geometric characteristics (modulus of resistance) are inherently higher than those of a round tube of the same weight. This lays the foundation for increased rigidity and stability of the frame while reducing the number of parts and simplifying assembly, as additional gussets or stiffeners are eliminated.

[0018] The next step involves forming the legs from the pipe blanks. Each leg is manufactured in one piece and has an L-shape. This is achieved either by bending the pipe on a pipe bender or by welding two sections at right angles and then cleaning the seam. Producing the legs as a single piece, rather than as multiple pieces, is key: a monolithic structure in a corner joint performs significantly better than any welded or bolted assembly. This directly contributes to the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, as the traditional design, which requires a separate vertical post and horizontal frame, is replaced by a single, universal component.

[0019] When designing the leg geometry, the calculated dimensions are strictly observed. The vertical portion of the L-shaped element (leg height) is less than 50 cm, and the horizontal (underseat) portion is less than 23 cm. These limitations are the result of mathematical load modeling: the formula for the bending moment for the console M = F × L shows that reducing the leg height L proportionally reduces the load on the hazardous section during bending, and the formula M_max = (q × l²) / 8 demonstrates the quadratic dependence of the moment on the span length l. Compliance with these parameters ensures that the stresses in the material do not exceed permissible values, which increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, eliminating the need for struts or additional supports.

[0020] Mounting holes are prepared in the horizontal (under-seat) section of each leg. Two holes are drilled. The first hole is located 3.5 cm from the end (edge) of the leg. The second hole is drilled 8.5 cm from the same edge. This location was chosen based on strength calculations for the connections. A distance of 3.5 cm (including half the hole diameter) is the minimum allowable to prevent chipping or crushing of the metal under load (σ_cm = F / (d × t)), and the increased base between the holes (5 cm) effectively absorbs the moment tending to rotate the joint (M = F × h), reducing the load on each fastener. This precise hole placement significantly increases the rigidity and stability of the frame while reducing the number of parts and simplifying assembly, as it allows for only two attachment points per joint without compromising reliability.

[0021] The frame assembly process is extremely technological. All four L-shaped legs are connected under the seat. Their horizontal sections are laid crosswise on the underside of the seat, forming a supporting structure. The elements are secured using threaded connections (bolts) through pre-drilled holes.

[0022] Thus, the entire set of described actions—from selecting a rectangular profile and manufacturing solid L-shaped legs with mathematically justified dimensions and hole patterns to a cross-shaped joint with a minimum number of connections—works toward a single goal. The result is a product that demonstrates high strength characteristics and reliability, confirming the increased rigidity and stability of the frame while simultaneously reducing the number of parts and simplifying assembly, making the structure not only reliable but also easy to manufacture.

Claims

1. A stool comprising a seat and a supporting frame including legs, characterized in that the legs are made of rectangular tubes, each leg being a solid L-shape, while forming a cross-shaped configuration with the remaining legs under the seat.

2. A stool according to paragraph 1, characterized in that the height of the vertical part of the L-shaped leg is less than 50 cm.

3. A stool according to item 1, characterized in that the length of the horizontal part of the L-shaped leg is less than 23 cm.

4. A stool according to paragraph 1, characterized in that the horizontal part of the L-shaped leg contains at least two mounting holes.

5. A stool according to item 4, characterized in that the first hole is located at a distance of 3.5 cm from the edge of the leg, and the second hole is located at a distance of 8.5 cm from the edge of the leg.