US 5,806,828 AGranted

Chair with a seat that returns to a predetermined height and angular rest position when unoccupied

AssigneeStabilus GmbH

InventorsWolfgang Rothe, Klaus Koch, Michael Hewel, Oliver Schuttler

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Abstract

Height adjustable object carrier column for use as a chair column of a revolving chair. The head area of the chair is moved back to a rest height and angular orientation with respect to the foot area of the chair upon relief of the chair load. The head area can be adjusted with respect to the foot area, by height adjustment apparatus, to different rest heights. Height adjustment is provided in the form of a hydraulic or a hydropneumatic or a spring-hydraulic or a pneumatic actuator with a cylinder assembly and a piston rod assembly which are coaxial to a telescope axis. The height adjustment apparatus includes internal biasing structure and first arbitrarily adjustable and second automatic blocking devices, whereby following a reduction of the load on the object carrier column, the second blocking device is released, and the height adjustment apparatus is moved toward a specified limit position, and the stop moves the object carrier column into the specified rest angular orientation.

Claims16

Dependent claims

A chair column for a height-adjustable revolving chair, said chair column having a longitudinal axis, said chair column comprising:

an adjustable-length assembly;
said adjustable-length assembly comprising:
a first end;
a second end;
a first tube member rotatable about the longitudinal axis;
said first tube member being translatable along the longitudinal axis;
said first tube member comprising a first portion;
said first portion comprising said first end of said adjustable-length assembly;
said first portion comprising structure to attach a chair seat;
a second tube member;
said second tube member comprising a second portion;
said second portion comprising said second end;
said second portion comprising structure to attach to a chair base;
and
said second tube member comprising apparatus to guide the axial and rotational movement of said first tube member;
biasing structure to urge said first end away from said second end;
a blocking device to limit retraction of said adjustable-length assembly upon application of a substantially axial load directed from said first portion towards said second portion;
a height-adjustment device to adjust the retraction of said adjustable-length assembly while under the axial load;
a stopping device to limit the extension of said adjustable-length assembly by said biasing structure upon removal of the axial load;
said stopping device comprising a return device;
said return device comprising apparatus to rotate said first tube member to a fixed angular position with respect to said second tube member upon the removal of the axial load;
said biasing structure comprising a pressure cylinder device;
said pressure cylinder device comprising:
said first tube member;
said first tube member comprising a pressure cylinder;
a piston;
said piston being disposed within said pressure cylinder;
said piston being disposed to separate said pressure cylinder into a first work chamber and a second work chamber;
structure to seal the ends of said first work chamber and said second work chamber;
each of said first work chamber and said second work chamber containing an operating fluid;
a flow connection disposed to fluidly connect said first work chamber and said second work chamber;
said pressure cylinder device comprising said blocking device;
said blocking device comprising:
structure to close said flow connection upon retraction of said adjustable-length assembly;
structure to open said flow connection upon extension of said adjustable-length assembly;
said blocking device being a first blocking device;
said pressure cylinder device comprising said height-adjustment device;
and
said height-adjustment device comprising:
a second blocking device to close said flow connection;
and
said second blocking device comprising structure to open and close said flow connection.

39 more elements

A height-adjustable support column as for supporting a seat of a chair, said support column comprising:

a first portion;
said first portion comprising structure to attach a chair seat;
said first portion being disposed about a longitudinal axis;
the longitudinal axis being an axis of rotation of said first portion;
a second portion;
said second portion comprising structure to attach to a chair base;
said first portion being non-rotatably connected to said second portion upon said first portion being disposed in a first longitudinal position upon the chair seat being unoccupied;
said first portion being rotatable connected to said second portion upon said first portion being disposed in a second longitudinal position upon the chair seat being occupied;
said rotatable connection comprising structure to rotate the chair seat about a chair base to any desired angular seating position;
the second longitudinal position corresponding to a seating height of the chair seat;
a height-adjustment device to adjust the second longitudinal position to adjust the seating height of the chair seat;
first returning apparatus to return said first portion from the second longitudinal position to the first longitudinal position upon the chair seat being unoccupied;
and
said first returning apparatus comprising second returning apparatus to return said first portion to a predetermined angular position relative to said second portion upon the first portion being displaced to the first longitudinal position;
said height-adjustment device comprising blocking apparatus to limit the longitudinal displacement of said first portion from the first longitudinal position to the second longitudinal position upon the chair seat being occupied;
said first returning apparatus comprising a stopping device to limit the longitudinal displacement of said first portion from the second longitudinal position to the first longitudinal position upon the chair seat being unoccupied;
said height-adjustment device comprising a fluid actuation device;
said fluid actuation device comprising a cylinder having an inside diameter;
said cylinder being disposed concentrically about the longitudinal axis;
said fluid actuation device comprising a piston;
said piston being disposed concentrically about the longitudinal axis;
said piston being disposed within said cylinder;
said piston being disposed to divide said cylinder into a first work chamber and a second work chamber;
each of said first work chamber and said second work chamber comprising structure to contain a pressurizing fluid of said fluid actuation device;
said blocking apparatus comprising structure to seal said first work chamber from said second work chamber;
said piston being disposed in a first longitudinal position with respect to said cylinder upon the chair seat being occupied;
said piston being disposed in a second longitudinal position with respect to said cylinder upon the chair seat being unoccupied;
said fluid actuation device comprising a valve;
said valve comprising structure to selectively seal said first work chamber from said second work chamber;
said valve comprising structure to selectively unseal said first work chamber from said second work chamber;
said structure to selectively unseal said first work chamber from said second work chamber comprising apparatus to adjust the seating height of the chair;
said blocking apparatus comprising a first blocking structure and a second blocking structure;
said first blocking structure being disposed to operate in parallel with said second blocking structure;
said first blocking structure comprising said structure to selectively seal said first work chamber from said second work chamber;
said second blocking structure comprising structure to bypass said blocking apparatus upon the chair seat being unoccupied;
said bypass structure comprising:
a flow connection to pressurize fluid communication between said first work chamber and said second work chamber;
said flow connection comprising:
said piston comprising at least one control diameter;
said inside diameter of said cylinder and said at least one control diameter of said piston being disposed to form a control groove;
a first bore disposed in said piston, said first bore extending between said first work chamber and said control groove;
and
a second bore disposed in said piston, said second bore extending between said control groove and said second work chamber;
a control device to seal and unseal said flow connection;
said control device being disposed within said control groove;
apparatus to longitudinally displace said control device to a sealing position to seal said flow connection upon the chair seat being occupied;
and
apparatus to longitudinally displace said control device to an unsealing position to unseal said flow connection and to bypass said blocking apparatus upon the chair seat being unoccupied.

45 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/691,979Filed 2 Aug 1996
Priority: DE 195 28 645.64 Aug 1995
Granted: 15 Sep 1998
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

A47C 3/18
Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats: chairs or stools with rotatable seat
A47C 3/185
Chairs or stools with rotatable seat: self-returning to the original position
A47C 3/30
Chairs or stools with vertically-adjustable seats: with vertically-acting fluid cylinder
F16M 11/18
Heads: with mechanism for moving the apparatus relatively to the stand