Classifications

• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
  • A47C3/18—Chairs or stools with rotatable seat
• • A—HUMAN NECESSITIES
  • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
  • A47C—CHAIRS; SOFAS; BEDS
  • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
  • A47C3/18—Chairs or stools with rotatable seat
  • A47C3/185—Chairs or stools with rotatable seat self-returning to the original position

Definitions

• the invention relates to a hub for a rotatable chair. More specifically, the invention relates to a chair having a support column on which the chair is carried and around of which it can be rotated. Specially, the invention relates to a hub according to the independent claim.
• Chairs having a central column are popular in particular as office chairs, but also for private use when a there is a need for a chair which is rotatable while stationary. Such chairs may be provided with various mechanisms for rotation, tilting, gas or spring suspension in the column, among others. A prerequisite for such a chair is a robust base structure, with or without wheels for moving around.
• a hub for a rotatable chair comprising a swivel shaft and a swivel shell arranged rotatably around the swivel shaft.
• a locking piston is placed axially movably within the swivel shaft there is a hole in the swivel shaft having a ball placed movably in the hole.
• the swivel shell has a pocket that can be aligned with the hole so that an actuating mechanism can be used for moving the locking piston in longitudinal direction of the swivel shaft for pushing the ball to the pocket and releasing it therefrom through the hole.
• the aim of the invention is to enable locking of a rotatable chair so that sitting down on the chair and rising from the chair can be done more safely.
• the locking mechanism is based on locking balls that can be pushed into locking pockets for locking the rotation movement and released from them to enable rotation.
• FIGURE 1 illustrates a hub for a in accordance with at least some embodiments of the present invention.
• the main body of the hub is a swivel shaft 1.
• the swivel shaft 1 has a conical part around which is mounted a swivel shell 4.
• the swivel shell 4 is connected to the swivel shaft 1 by two bearings 3 to allow rotation of the swivel shaft 1 in relation to the swivel shell 4.
• the bearings 3 are roller bearings, but any type of bearings can be used.
• the swivel shaft 1 or the swivel shell 4 is mounted on the base or stand of the chair and the seat part of the chair is mounted on the other part.
• An activating pin 6 is set in a boring in the swivel shaft 1 and it extends from the end of the swivel shaft 1.
• a spring 7 is arranged between the end of the activating pin 7 and the swivel shaft 1. The spring 7 pushes the activating pin 7 towards a locking position.
• the locking piston 7 On the opposite end of the activating pin 7 in relation to the spring is a locking piston 5.
• the locking piston 7 has a first cylindrical part on which the activating pin 7 is attached and a second cylindrical part having a larger diameter and conical part connecting the cylindrical parts.
• the locking piston 5 is seated on a recess 10 at the end of the swivel shaft 1.
• the recess 10 is longer than the locking piston 5 so that the locking piston 5 can move in the recess.
• At the side wall of the recess 10 are four holes 8 extending through the side of the swivel shaft 1. In the holes are mounted four balls 2.
• the balls 2 are made of steel, for example, but other construction materials like plastics, ceramics or other metals or metal alloys can be used.
• the swivel shell has 8 pockets placed at the same plane in the cross section as the holes 8.
• the holes 8, and the balls 2 can be aligned with the pockets by rotating the swivel shaft 1 in relation to the swivel shell 4.
• the mechanism operates as follows:
• the rotating, unlocked position is depicted in FIGURES 2 and 4 .
• the activating pin 6 is activated by pushing it against the spring 7.
• An activating mechanism is not depicted here as many types of mechanisms can be used.
• the type of activating mechanism is defined by design and construction of the chair. For example, a lever or push button at the side of the chair can be utilized.
• the activating pin 6 is pushed, the locking piston 5 moves within the recess 10 away from the end of the recess so that the conical part of the locking piston 5 is set at the level of the holes 8.
• the balls rest now on the conical part and the smaller first cylindrical part of the locking piston 5, allowing the balls to retreat from the holes 8 towards the recess 10 and the locking piston 5.
• the number of the balls 2 can be anything between 1 - 10. At least one is needed for locking and the highest number is limited by space requirements for constructional reasons.
• the angle between the holes 8 on the locking axle 1 has to be dividable with the number of the pockets 9 in the star pattern of the swivel shell 4 to allow locking.
• the pushing function between the activating pin 6 and the spring 7 can be opposite, i.e the activating rod can be in upside-down position in relation to the position in the FIGURES 1 and 2 and a mechanism can be used to pull locking piston upwards instead of pushing the activating pin 6 downwards.
• the placement of the spring can be varied and different kinds of springs can be used, for example types from a group comprising coil spring, gas spring, elastic cushion spring, leaf spring or magnetic spring.
• the invention can be utilized for manufacturing chairs.

Landscapes

• Chairs Characterized By Structure (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=91829123

Family Applications (1)

Country Status (3)

Citations (5)

• 2024
  • 2024-07-04 EP EP24186597.1A patent/EP4674316A1/fr active Pending
• 2025
  • 2025-06-20 CA CA3277913A patent/CA3277913A1/en active Pending
  • 2025-07-01 US US19/256,265 patent/US20260007236A1/en active Pending

Patent Citations (5)

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