Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C1/00—Chairs adapted for special purposes
  • A47C1/02—Reclining or easy chairs
  • A47C1/031—Reclining or easy chairs having coupled concurrently adjustable supporting parts
  • A47C1/032—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest
  • A47C1/03255—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest with a central column, e.g. rocking office chairs
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C1/00—Chairs adapted for special purposes
  • A47C1/02—Reclining or easy chairs
  • A47C1/031—Reclining or easy chairs having coupled concurrently adjustable supporting parts
  • A47C1/032—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest
  • A47C1/03261—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest characterised by elastic means
  • A47C1/03266—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest characterised by elastic means with adjustable elasticity
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C1/00—Chairs adapted for special purposes
  • A47C1/02—Reclining or easy chairs
  • A47C1/031—Reclining or easy chairs having coupled concurrently adjustable supporting parts
  • A47C1/032—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest
  • A47C1/03261—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest characterised by elastic means
  • A47C1/03272—Reclining or easy chairs having coupled concurrently adjustable supporting parts the parts being movably-coupled seat and back-rest characterised by elastic means with coil springs

Definitions

• the present invention relates to a tilt tension adjustment mechanism of a seat incorporating the connection with at least one backrest arm of said seat.
• Known mechanisms are generally based on a torsion spring disposed at the shaft of rotation of the backrest, and whose stiffness can be adjusted by the user with the aid of an outer wheel.
• the adjustment of the voltage is long, since it requires a large number of rotations of said wheel (typically from 10 to 20 or even 25 turns to scan the entire amplitude of the adjustment), which is hardly comfortable for said user.
• the object of the present invention is to provide a system with a quick adjustment, with a usual rotary dial control mode, which however has a limited stroke (1 to 2 turns).
• the system of the invention must guarantee the absence of a shirt-pulling effect and an excessive rise in the front of the seat (no compression zones under the thighs), while having a good balance in all work positions without obligation to block the position.
• the synchronized adjustment mechanism of the invention which applies to seats whose backs are pivotally mounted on a support placed under the base of the seat surmounting the base, is characterized in principal that it comprises: - at least one tension spring prestressed to at least one predetermined minimum tension;
• At least one compression spring whose stroke is adjustable
• the compression and traction springs are arranged on either side of the axis of tilting of the backrest.
• the use of these two springs with a combined action makes it possible to have a working curve very close to that obtained with the aid of traditional torsion springs.
• one of the ends of each spring is mounted on the support of the free seat in rotation axis parallel to the axis of tilting of the backrest, the other end being connected to a plate secured to the tree of tilting of the backrest.
• Said support comprises in fact a cradle provided with a bottom and side walls, a shaft rotatably mounted in said side walls separating said cradle in two spaces respectively receiving at least one compression spring and at least one tension spring, said shaft being on the one hand surmounted by the aforementioned plate and supporting on the other hand at least one tilting backrest arm.
• the springs are oriented so that their axes are in at least one plane perpendicular to the axis of tilting of the backrest.
• the plans in question are also of course perpendicular to the average plane of the seat.
• Each compression spring is mounted on a telescopic shaft having two end heads on which the axial ends of the spring are supported.
• each compression spring is effected in particular by varying the length of the telescopic shaft, and therefore the energy accumulated by the spring.
• One of the heads of said shaft is articulated to the cradle, the other head resting against a curved surface of the plate along which it can move along a path in a plane perpendicular to the tilting axis, to modify the length of the shaft and consequently the tension of the spring.
• Said curved surface therefore does not correspond to an arc having a diameter equal to the shortest length of the telescopic shaft, but to an arc of greater diameter, hence a variation of the length of this shaft depending on the direction moving the head in contact with the curved surface.
• said curved surface is provided with lateral walls so as to constitute a guide rail for an outgrowth of the head moving between said walls.
• the walls in question provide lateral guidance to maintain the displacement of the axis of the telescopic shaft in a single plane.
• the curved surface, the head applied and the walls are fitted with a notch.
• each setting position of the control lever actuated by the user bijectively corresponds to a particular position of the telescopic shaft, and a corresponding torque of the compression and traction springs.
• the head applying on the curved surface of the plate has a lateral lug cooperating with the two parallel branches of a fork movable in rotation and whose rotary displacement drives the lug and therefore the head along the curved surface of the platinum, the lug being otherwise free in translation within the branches.
• This system ensures the rotational displacement of the telescopic shaft, and therefore the change of orientation of the axis of the compression spring.
• said fork is secured to a member having a toothed arcuate track meshing with a toothed wheel disposed on a shaft controlled in rotation by a wheel.
• the user actuates the latter, he rotates the member comprising the fork via the toothed wheel / the track, and thus to change the inclination of the axis of the compression spring.
• FIG. 1 is a perspective view of the cradle disposed under the seat cushion and comprising means for adjusting the tilting tension of the backrest of said seat;
• FIG. 4 is a diagram showing several operating curves of a mechanism according to the invention.
• the cradle (1) located under the seat of the seat (not shown) comprises two springs: a compression spring (2) and a tension spring (3) arranged on both sides the tree (4) for tilting the backrest, which is subject to the branches (5, 5 ') for fixing the backrest disposed laterally to the cradle (1).
• the springs (2, 3) are separated by a plate (6) with which they cooperate.
• the compression spring (2) is mounted on a shaft telescopic (7), free to rotate at its distal end of the plate (6) around the shaft (8).
• the other end of the shaft (7) has a head (9) which is movable relative to a notched curved surface (10). This notched surface (10) is limited, laterally, by two walls (11, 11 ') also notched, the assembly forming a sort of curved curved slide.
• the spring (2) disposed on the shaft (7) biases the head (9) in contact with the toothed surface (10).
• the traction spring (3) is mounted at one of its ends to the cradle (1), via a terminal hook cooperating with a lug (13) of the cradle (1) of suitable shape. At its other end, the tension spring (3) is fixed to the plate (6) in an orifice (14) formed in a fin (15) of the plate (6) oriented perpendicular to the toothed slide (10). As will be seen in the following, the orifice (14) is provided so that the fixing of the end of the tension spring (3) can take several discrete positions also allowing adjustment.
• the shape of the orifice (14) appears more precisely in Figure (3), and comprises in fact three parallel grooves (16) each of which can accommodate the uncoupled end of the tension spring (3).
• the orientation of the spring axis (3), and therefore its tension, depends on the groove (16) in which the end of the spring is fixed.
• the operation is as follows: when the user wants to change the tension of its backrest, it acts on the knob (17) which rotates a shaft (18) at the end of which is secured a toothed wheel or notched (19) cooperating with teeth or notches of a notched curvilinear surface (20) formed on the periphery of the inner recess of an oblong piece (21).
• the oblong piece (21) Opposite the toothed surface (20), the oblong piece (21) comprises a fork (22), more visible in FIGS. 2 and 3, comprising two branches (23, 23 ') enclosing a lug (24) protruding from the head (9).
• This lug can slide inside the two branches (23, 23 '), and moves relatively to the latter as the oblong piece (21) rotates in one direction or the other, which direction is controlled by the rotation of the control wheel (17).
• This figure also shows that the head (9) has a notched curved end surface (26), which prevents any undesirable movement of the shaft (7) compression spring which would result in changing the setting theoretically determined by the relative position of the toothed wheel (19) and the toothed surface (20).
• FIG. 4 shows examples of curves taken with a system according to the invention, using different combinations of tension and compression springs, when the tension is minimum (lower group of curves) and maximum (higher group).
• the values on the abscissa correspond to the tilting angle, ranging from 0 ° to 25 °, while the values or ordinates are the resistant torques of the file going from 25000 to 260 000 N / mm.
• the curves are almost linear, with a slope that augurs the right balance at each position.
• the major feature of the invention is the combination of a compression spring (2) and a tension spring (3) in place of a torsion spring as conventionally used in this type of mechanism.
• the actual control means an example of which has been previously discussed, should not be considered as limiting of this invention.

Landscapes

• Health & Medical Sciences (AREA)
• Dentistry (AREA)
• General Health & Medical Sciences (AREA)
• Chairs Characterized By Structure (AREA)
• Chairs For Special Purposes, Such As Reclining Chairs (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=39580281

Family Applications (1)

Country Status (2)

Families Citing this family (5)

Family Cites Families (5)

• 2007
  • 2007-03-08 EP EP07731117A patent/EP2129263A1/de not_active Withdrawn
  • 2007-03-08 WO PCT/FR2007/000420 patent/WO2008110669A1/fr not_active Ceased

Non-Patent Citations (1)

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