GB2552732A

GB2552732A - Device for tilting the backrest of office chairs

Info

Publication number: GB2552732A
Application number: GB1705337.2A
Authority: GB
Inventors: Berbegal Perez Vicente
Original assignee: Actiu Berbegal y Formas SA
Current assignee: Actiu Berbegal y Formas SA
Priority date: 2016-08-02
Filing date: 2017-04-03
Publication date: 2018-02-07
Anticipated expiration: 2037-04-03
Also published as: ES2596510A1; GB201705337D0; DE102017205699B4; GB2552732B; FR3054781B1; DE102017205699A1; FR3054781A1; ES2596510B1

Abstract

Disclosed is a device suitable for tilting the backrest of office chairs, said device comprising coil spring 3 disposed inside a casing, a side knob, a rod attached to the side knob, and a U-shaped part 7 disposed about the casing. One end of the rod comprises a pinion, and one side of the U-shaped part comprises a notched rack 13 to engage the pinion of the rod. Two opposing arms of the U-shaped part comprise inclined grooves 12 for receiving a through pin 11. The casing also comprises a through hole 10 for receiving said through pin, such that the U-shaped part and casing are connected by the through pin in use. An end of the casing distal the through hole comprises a connecting means 5 for connecting the device to a front portion of a chair structure in use. Longitudinal movement of the U-shaped part affects upward and/or downward movement of the coil spring by means of the inclined grooves, and the through pin that is forced to run through said grooves.

Description

(54) Title of the Invention: Device for tilting the backrest of office chairs Abstract Title: Device for tilting the backrest of office chairs (57) Disclosed is a device suitable for tilting the backrest of office chairs, said device comprising coil spring 3 disposed inside a casing, a side knob, a rod attached to the side knob, and a U-shaped part 7 disposed about the casing. One end of the rod comprises a pinion, and one side of the U-shaped part comprises a notched rack 13 to engage the pinion of the rod. Two opposing arms of the U-shaped part comprise inclined grooves 12 for receiving a through pin 11. The casing also comprises a through hole 10 for receiving said through pin, such that the U-shaped part and casing are connected by the through pin in use. An end of the casing distal the through hole comprises a connecting means 5 for connecting the device to a front portion of a chair structure in use. Longitudinal movement of the U-shaped part affects upward and/or downward movement of the coil spring by means of the inclined grooves, and the through pin that is forced to run through said grooves.

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DEVICE FOR TILTING THE BACKREST OF OFFICE CHAIRS

DESCRIPTION

OBJECT OF THE INVENTION

The present invention relates to a device for tilting the backrest of office chairs, provided to allow the user to tilt the backrest of an office chair more efficiently and in a simpler manner.

The object of the invention is to incorporate a device in office chairs to allow adjusting the tension of the backrest and adapt the resistance offered by the latter depending on the weight of the user, and therefore the force exerted by said user on such backrest, which all allows offering a very ergonomic and comfortably chair for any user, regardless of their weight.

BACKGROUND OF THE INVENTION

The backrest of some office chairs has the particularity of being tilting in order to adapt to user demands, tilting being performed by manually operating of a set screw, such that although mechanisms of this type carry out the function for which they were designed, these systems are slow in terms of their operation and complicated for users.

Nevertheless, devices that allow adjusting the degree of resistance offered by the backrest of an office chair are known, such as the one shown in patent document 2437094T3, which belongs to the same applicant as the present and on the basis of which the present invention has been developed, such that said registration describes a chair in which the resistance of the backrest is adjusted by means of an horizontally arranged coil spring, i.e., with zero inclination, attached to a side rod ending in a manual operating knob so that the user can adjust the resistance the backrest of the chair is to offer when the user is sitting in the same.

-1 However, this device has the drawback that the adjustment of the resistance of the coil spring by the user is very slow, and the adjustment thereof can be very tedious for the user itself until finding a suitable setting, and all this resulting from the horizontal and invariable arrangement of the coil spring whereby adjustment is carried out.

DESCRIPTION OF THE INVENTION

The proposed device for tilting the backrest of office chairs solves the drawbacks set forth above in a fully satisfactory manner based on a simply but highly effective solution.

To that end, the device is based on a coil spring being assembled inside a casing, forming an assembly which, at the rear end, is located in a U-shaped part, the lower outer portion of the transverse branch of U-shaped part being provided with a notching or rack with which a pinion provided at the end of the rod into which the manual operating knob extends.

All this is so such that when the user operates the operating knob, the meshing that takes place on the rack-like notching of the U-shaped part implies a movement of said U-shaped part.

This movement translates into an angular tilting of the coil spring resulting from the fact that two inclined grooves or elongated holes are provided on the sides of said U-shaped part, in which grooves there is located a transverse pin which also passes through the casing of the coil spring.

Therefore, since said grooves are oblique with respect to the direction of movement of the U-shaped part by the operation the rod of the corresponding knob, the movement of said Ushaped part forces pin to move along said oblique grooves, forcing the casing of the coil spring to tilt up or down, depending on if the U-shaped part moves to the right or to the left.

The tension of the backrest to which said casing-coil spring assembly is connected is adjusted in a quick and simple manner.

-2In summary, it can be said that the coil spring is supported on an adjustment element for adjusting the inclination of the spring, and which adjustment element consists of said Ushaped part, all allowing the user after operating the corresponding rod, to set the pushing force of the backrest according to the user’s needs.

Advantageously, enabling modification of the inclination of the coil spring thus generates, with a small movement, the pushing force of the spring, which will be different depending on the degree of inclination. This pushing force of the coil spring is transmitted to the backrest, which will offer greater resistance for heavier people and will offer less resistance when tilting the backrest when the person using it weighs less.

Finally, a series of recesses are provided on the outer surface of the sides of the U-shaped part, forming an horizontal alignment, between which lugs provided on side parts arranged on the U-shaped part like horizontal guides and fixed to the structure of the seat can be selectively placed, both lugs being aided by springs and arranged between such side parts and the U-shaped part.

Therefore, when the lugs are located between two projections, they establish a kind of safety immobilization for immobilizing the assembly if the user is supported against the backrest and tries to act on the manual operating rod.

DESCRIPTION OF THE DRAWINGS

To complement the description that will be made below and for the purpose of aiding to better understand the features of the invention according to a preferred practical embodiment thereof, a set of drawings is attached as an integral part of said description, wherein the following is depicted with an illustrative and non-limiting character:

Figure 1 shows an exploded perspective view of the main parts participating in a device for tilting the backrest of office chairs performed according to the object of the present invention.

-3Figure 2 shows a perspective view of a detail of the device applied in a chair.

Figure 3 shows a different perspective view from the one of the assembly in Figure 1, and in which all the parts participating in the mechanism of the invention can be seen.

Figure 4 shows a detail of the chair receiving the device of the invention depicted in Figure 2 and seen from the rear angle.

PREFERRED EMBODIMENT OF THE INVENTION

In view of the described figures, it can be seen how the proposed device for tilting the backrest of office chairs is provided to allow adjusting the tension of the backrest (1) of a chair, with a base structure (2) in which there is arranged a coil spring (3) housed in a casing (4) which, at one end and through a type of crosspiece (5), is assembled in an articulated manner on the front portion of the base structure (2) of the seat, whereas in the rear portion thereof it has securing appendages (6), as depicted in Figure 1.

The novelty of the invention is that the assembly formed by the coil spring (3) inside the casing (2) is connected to a U-shaped part (7) which is located below the rear section of the assembly formed by the casing (4) with the coil spring (3), such that said U-shaped part (7) houses between its side branches (8) and its transverse branch (9) the rear section of the assembly formed by the casing (4) and coil spring (3).

In addition, the structure corresponding to the casing (4) of the spring (3) has elongated holes (10) on its sides, in which a transverse pin (11) which in turn moves at its ends in elongated holes (12) provided for that purpose on the sides (8) of the U-shaped part (7) is positioned for the purpose explained below.

The intermediate transverse branch (9) of the U-shaped part (7) has on its outer face a series of projections (13) forming a type of rack in which a toothed pinion provided in the rod (14) ending in the manual operating knob (20) meshes.

-4All this is done such that when this knob (20) is operated and the rod (14) therefore turns, the pinion incorporated at the inner end of such rod (14) acts on the projections of the rack (13), tending to move the U-shaped part (7) but making it tilt, in accordance with the fact that it is anchored, through the elongated holes (12) and slots (10) of the side parts (8) and casing (4), respectively, carrying out the tilting of the assembly of the coil spring (3) with its corresponding casing; i.e., tilting of the coil spring (3) takes place, and therefore the tension of the backrest connected to this mechanism is adjusted.

Furthermore, recesses (19) are provided on the sides (8) of the U-shaped part (7), specifically four recesses, forming respective horizontal and lateral alignments, as shown in Figure 1, between which lugs (15) can be selectively fitted aided by springs (16) located in holes (17) of side parts (18) which are fixed to the base structure (2), acting like guide elements for the movement of the U-shaped part (7).

Accordingly, the lugs (15) are sandwiched between the fixed side parts (18) and the outer surface of the sides (8) of the U-shaped part (7), such that the springs (16) always tend to push the lugs (15) between two consecutive projections (19), thereby bringing about the immobilization preventing the backrest from titling without operating the rod (14).

Finally, Figure 4 depicts the chair receiving the device of the invention, seen from the side of the backrest, where the base structure of the chair (2) can be seen, having projections (21) in its rear portion where there are introduced securing appendages (6) provided at the rear portion of the casing for the purpose of offering the immobilization of the assembly of the backrest if user is supported against the backrest and tries to act on the manual operating rod (20).

Claims

1. A device for tilting the backrest of office chairs, applicable in that type of chairs with a swiveling base connected with an adjustable and tilting backrest with respect to a seat structure, comprising an adjustable axial spring manually tensed through a side knob for adjusting the backrest, characterized in that said spring is assembled inside a casing, forming an assembly which at one end is linked to the front portion of the structure of the seat, being connected through the rear portion with the side operating lever, which has at its end a pinion meshing with a rack-like notching arranged in the outer portion of the transverse branch of a U-shaped part, the latter being movable due to the effect of said pinion, the rear portion of the assembly formed by the spring and the casing thereof housing said U-shaped part, with the particularity that the sides of the U-shaped part have inclined grooves in which a through pin moves through a hole arranged in the casing of the spring, whereby the inclination and/or descent of the spring-casing assembly during operation in one rotational direction or the other of the manual operating rod are adjusted by means of said inclined grooves.

2. The device for tilting the backrest of office chairs according to claim 1, characterized in that the sides of the U-shaped part are externally provided with slots in which can be selectively fitted respective lugs, aided by springs and arranged between such outer faces of the side branches of the U-shaped part and the inner face of outer side parts which are fixed to the structure of the seat.

3. The device for tilting the backrest of office chairs according to claim 1, characterized in that the casing has in its rear portion securing appendages for immobilizing a backrest assembly.

Intellectual

Property

Office

Application No: GB1705337.2 Examiner: Mr David Smitten

3. The device for tilting the backrest of office chairs according to claim 1, characterized in that the casing has in its rear portion securing appendages for immobilizing the backrest assembly.

-6Amendments to the Claims have been filed as follows:1. A device for tilting the backrest of an office chair, the device comprising:

an adjustable axial spring provided inside a casing, the adjustable axial spring and casing together forming a spring-casing assembly having a first end connectable to a front portion of a seat structure of an office chair and rear portion located in a U-shaped part, the U-shaped part comprising a pair of sides connected by a transverse branch; and a side operating rod connected at the rear portion of the assembly for manually adjusting the backrest by adjusting the tension of the adjustable axial spring, the side operating rod ending in a manually operating knob;

wherein:

the side operating rod is provided with a pinion meshing with a rack-like notching arranged in an outer portion of the transverse branch of the U-shaped part, whereby the Ushaped part is movable due to the effect of said pinion; and the sides of the U-shaped part have inclined grooves in which a through pin moves through a hole arranged in the casing, whereby the inclination and/or descent of the springcasing assembly during operation in one rotational direction or the other of the side operating rod are adjusted by means of said inclined grooves.

2. The device for tilting the backrest of office chairs according to claim 1, characterized in that the device further comprises outer side parts for fixing to a seat structure, wherein the sides of the U-shaped part are externally provided with slots in which can be selectively fitted respective lugs, aided by springs and arranged between such outer faces of the side branches of the U-shaped part and the inner face of the outer side parts.