EP3643200B1

EP3643200B1 - Lift system for desks

Info

Publication number: EP3643200B1
Application number: EP18208380.8A
Authority: EP
Inventors: José Acácio da Rocha Ferreira
Original assignee: Famo Industria De Mobiliario De Escritorio Lda
Current assignee: Famo Industria De Mobiliario De Escritorio Lda
Priority date: 2018-10-22
Filing date: 2018-11-26
Publication date: 2024-03-27
Anticipated expiration: 2038-11-26
Also published as: EP3643200A1; EP3643200C0

Description

Technical field

This application describes a lift system for a desk.

Background

One of the trials conducted to define advanced work safety and hygiene systems at Loughborough University in the UK reached the conclusion that using furniture such as desks or drawing boards that could be adjusted to the height of the worker enhances productivity and lessens fatigue.
This year long trial assessed 146 workers with the National Health Service in the UK. A group of 77 workers received height-adjustable workstations while the other 66 employees continued to work at standard desks. Members of the group assigned height-adjustable workstations were asked to spend as much time as possible on foot, being allowed to alternate between standing and sitting periods. In the course of the experiment, an increase was noted the time that the workers spent standing. Working conditions were evaluated every three months, and by the end of the trial, workers were already standing for 82 minutes. After twelve months, participants allocated to the height-adjustable desks were less anxious and reported a better quality of life, according to this study.
This consequently prompted the development of technical solutions for furniture, such as desks, drawing boards and others, whereby a lift system is assembled that allows a worker to adjust a working surface to a desirable height.
Document US 20170273453 discloses a height-adjustable desk with a desk structure, an anchor plate, a lifting device and a desktop plate. The desk structure has a main structure and a holding seat. The holding seat is physically included in the main frame. The anchor plate is mounted on the main structure. The lifting device is included in the holding bench and has a guide assembly and at least one cross-legged assembly. The cross-legged assembly is extended or folded into the reception area of the holding seat and is connected and activated by the activation assembly. The worktop is placed on the cross-legged assemblies in order to be moved upwards or downwards. A user looks at and operates a computer placed on the worktop when either standing or sitting and this prevents the user from remaining seated for a long period of time while working on the computer, thus avoiding harm to his/her health.
Document US 20180255919 discloses a height-adjustable device that comprises a base, one first scissor-like lift system connected to the base, with a first scissor-like lift system, a second scissor-like lift system connected to the base and with a second scissor-like lift system, a work surface connected to the first and second scissor-like lift systems, a support connected in a mobile fashion to the first scissor-like lift system and to the second scissor-like lift system that is mobile in relation to the work surface and a first energy storage element connected to the work surface and connected by at least one support tension element, wherein the first energy storage member is configured to put pressure on the support in a horizontal direction. Another similar lift system is shown for example in US 9 681 746 B1 .

Summary

This application describes a lift system for a desk comprising an upper structure and a lower structure with a slider slot connected by at least two support arms comprised of sliders at one of the ends and in a scissor-like structure, a system's actuator/lock and a spring system attached to the above-mentioned upper and lower structures, and an intermediate point on the scissor-like structure.
In one embodiment, the lift system for a desk includes a spring system with at least four springs in the upper structure and the lower structure.
According to the invention, the springs of the lift system for a desk work in a linear fashion along the entire length of the lifting/lowering slot.
According to the invention, at least one of the support arms of the lift system for furniture comprises a cavity.
According to the invention, the lift system's actuator/lock is manual, electric or of the gas-spring type.
According to the invention, the lift system's actuator/lock is mounted between the lower structure or the upper structure and the support arm, or the lift system's actuator/lock is mounted between the two support arms.

Brief Description

The present application describes a lift system for a desk, wherein the lift system may be activated through an actuator operated manually, electrically or pneumatically, allowing the user to easily regulate the height of the desktop.
The system presented herein works in a completely independent fashion, and may be used on any desk or work surface with no need for special alterations to the existing base structure. From a technical standpoint, the fact that the entire system is independent of the furniture structure means there is no need to alter or limit its layout or electrical installations.
In order to make the system compact and visually light, the actuator (which may be manual, electric or a gas-spring) is placed horizontally and may be mounted between the lower structure or the upper structure and the support arm (A), or between the two support arms (B).
In any of these cases, the reaction at A and B is given by the following ratio: R_AB = W/tan(alpha), wherein W corresponds to the mobile structure weight and load on the upper structure; alpha corresponds to the angle between the arm of the scissor-like lift and the horizontal plane and R_AB corresponds to the horizontal force needed to balance the mechanism.
This R_AB = W/tan (alpha) ratio raises a challenge, because when the alpha ratio moves towards zero, the R_AB will move towards the infinite, imposing very heavy forces on the structure.
In fact, the lift systems known thus far require additional effort from users in order to bring the desktop into the ideal position. The technical solution presented herewith is intended to make the height regulation operation simple and effortless for the user.
In order to solve this problem, a torsion spring system was developed, attached at points C, D and E of the furniture structure, as shown in Figure 1.
At least four torsion springs are attached at points C and D, operating in a linear fashion along the entire length of the desk. The purpose of these springs is to offset the weight of the structure.
An additional torsion spring is attached at point E. The spring is adjusted on one of the support arms. A cavity is created on the other support arm where the spring is mounted loosely. This system allows the spring to move freely along part of the stroke of the furniture, acting at the end of the stroke. The purpose of this spring is to create a greater initial force when the furniture is closed, minimizing the impulse required of the system's actuator/lock in order to initiate the movement.
As a result, the user can adjust the upper structure to an ideal height by activating the system's actuator/lock. When the structure is in movement, the user activates the system's actuator/lock, which may be manual, electrical or pneumatic. This system's actuator/lock is connected to the lower structure, which comprises a slider slot along which the sliders move, located at the ends of the support arms. After moving the structure, the user can activate the system's actuator/lock.

Brief description of the figures

For an easier understanding of the present application, the appended figures represent embodiments that, however, do not intend to limit the art disclosed herein.
Figure 1 illustrates a schematic presentation of a desk with the described lift system, wherein the references indicate the following elements:

A - Desktop support rim and mobile arm;
B - Mobile arm;
C - Torsion spring attachment point;
D - Torsion spring attachment point;
E - Torsion spring attachment point.

Figure 2 illustrates a schematic presentation of the lift system module in the open position, wherein the references indicate the following elements:

1 - Upper structural rim;
2 - Scissor-like structure;
3 - Lower structural rim.

Figure 3 illustrates a representation of detail "A" in Figure 1, wherein the references indicate the following elements:

4 - Slider slot;
5 - Slider.

Figure 4 illustrates a schematic representation of the lift system module shown in front view, wherein the references indicate the following element:
6 - System's actuator/lock.
Figure 5 illustrates a front view of the lift system module in the closed position.
Figure 6 illustrates a bottom view of the lift system, wherein the references indicate the following elements:

4 - Slider slot;
5 - Slider;
6 - System's actuator/lock;
E - Torsion spring attachment point.

Description of the embodiments

Referring to the figures, some types of embodiments are not described in greater detail, however, do not intended to limit the scope of the present application.
The present application describes a lift system for a desk.
According to the invention, as illustrated in the figures section, the furniture is a desk.
The lift system for desks thus comprises an upper structure (1) and a lower structure (3) connected by at least two support arms comprising sliders (5) located at one of the ends. The two support arms form a scissor-like structure (2). The system further compreses a system's actuator/lock (6) and a spring system, comprising torsion springs, attached to the above-mentioned upper (1) and lower (3) structures, in points (C) and (D), and an intermediate point (E) on the scissor-like structure (2). The lower structure (3) comprises slider slots (4) to receive the sliders (5).
This description naturally does not impose any constraints on the embodiments presented in this document, and any person with average knowledge in this field will be able to foresee many possibilities for the modification thereof, without departing from the scope of the invention as defined in the claims.

Claims

Lift system for a desk comprising:
- an upper structure (1) and a lower structure (3);

- at least two support arms (A, B) that form a scissor-like structure (2) connecting the upper structure (1) and the lower structure (3); wherein

- the lower structure (3) comprising a guide rail along which sliders move, located at the ends of the support arms (A, B);

- a torsion spring system, attached to the upper structure (1) and lower structure (3), the torsion spring system comprising at least four torsion springs in two attachment points (C, D), the torsion springs are configured to operate in a linear fashion along the entire length of the desk to offset the weight of the structure, and an additional torsion spring attached at an intermediate point (E) on the scissor-like structure (2), wherein the torsion spring in the intermediate point (E) is adjusted on one of the support arms (A, B) and to a cavity in the other support arm where the spring is mounted loosely allowing the spring to move freely along part of the stroke of the desk, acting at the end of the stroke to create a greater initial force when the desk is closed, minimizing the impulse required of a system's actuator/lock in order to initiate the movement;

- a system's actuator/lock (6) connected to the lower structure, and placed horizontally and mounted between the lower structure (3) or the upper structure (1) and the support arm (A), or between two support arms (B), wherein the system's actuator/lock (6) is manual, electric or of the gas-spring type.