According to an aspect of the present disclosure, a multi-step height adjuster includes a base tube portion including a first base tube and a second base tube vertically reciprocating inside the first base tube; a spindle portion including a first spindle installed inside the first base tube to vertically reciprocate and a second spindle installed inside the second base tube to vertically reciprocate; and an adjustment portion installed in the spindle portion to transmit power to the spindle portion, wherein the first spindle and the second base tube are integrally moved.

Storage of chairs when not in use, for instance in halls used by various groups, is a common problem which has been addressed by providing chairs that are stackable upon one another. Usually, this requires the chair to be composed of sloping legs and a sloping backrest, such that the seat of a lower chair can fit between the legs of an upper chair, and the backrest of the upper chair can rest on the backrest of the lower chair. It is desirable to be able to stack chairs with as small a vertical displacement as possible, usually limited by the depth of the seat, which is typically substantially horizontal. For instance, the base of an upper seat may sit (when stacked) on the upper portion of a lower seat. However, these chairs are usually mass produced and so designed to fit the average shape, which is not accommodating for a lot of people. The present invention provides a chair where seat 13 height, back 3 angle, seat 13 tilt and seat 13 roll are adjustable.

The present invention provides a double parallelogram vertical lifting device comprising a linkage mechanism and a pushing device. The linkage mechanism comprises a first shaft seat, a second shaft seat, a third shaft seat, an upper support unit movably coupled to the first shaft seat and the second shaft seat on both ends, and a lower support unit movably coupled to the second shaft seat and the third shaft seat on both ends. The upper support unit is provided with a first gear, and the lower support unit is provided with a second gear that meshes with the first gear. The pushing device has one end set on the upper support unit and the other end set on the lower support unit. The invention utilizes the interaction of the first gear and the second gear to generate a reaction force, which enables the lower support unit to cooperate with the upper support unit to move up and down synchronously, and achieves the effect of simple structure and large load capacity.

An adjustable lifting column for adjusting a piece of furniture comprises a drive assembly, a threaded spindle assembly comprising at least two concentrically arranged threaded spindles, of which an outer threaded spindle concentrically surrounds at least one further threaded spindle, a telescopic tube assembly comprising three concentrically arranged telescopic tubes, and a driver mechanism having an internal thread. The threaded spindle assembly is located within the telescopic tube assembly. Two adjacent threaded spindles of the threaded assembly have a common threaded connection. One of the at least two threaded spindles in the threaded spindle assembly is connected to the drive assembly for driving this one threaded spindle. The outer threaded spindle also has an external thread in which the internal thread of the driver mechanism engages. The driver mechanism is connected to a middle telescopic tube of the three telescopic tubes.

There is noticed a dynamic frame of the chair, which comprises a seat holder (1), to which a swivel sleeve (3) is demountably attached from one side, into which a spherical head (41) of a spherical thread swivel (4) with a threaded end piece (42) is tightly seated, to which a nut (7) is demountably attached and to which a silent block bushing (2) is demountably attached from the other side, to which an annular locking ring (6) with four locking undercuts (61) and four locking noses (62) is demountably attached from one side and a frame sleeve (5) with a sliding hole (53) and four sleeve noses (51) and four sleeve reinforcement pieces (52) is detachably fastened from the other side.

A chair including a seat, a seatback, a lift, at least one electric motor, and a brake and swivel system having a dual bearing Lazy Susan rotating mechanism, two soft bumpers, and a disc brake locking mechanism with a handle.

A chair including a seat, a seatback, a lift, at least one electric motor, and a brake and swivel system having a dual bearing Lazy Susan rotating mechanism, two soft bumpers, and a disc brake locking mechanism with a handle.

A motorized tilting mechanism for a reclining chair allows the chair be placed in a zero gravity position. A base frame comprising 2 sub-frames pivot in relation to each other to provide simple tilting mechanism.

A device that prevents the self-adjustment of a leveling glide for the tubular legs of various types of furniture, including tables and chairs, is disclosed. The device comprises a threaded insert for a furniture leveling assembly that includes a polymeric washer secured to the bottom of the threaded insert. The polymeric washer is aligned with the axis of the internally threaded of the threaded insert and has a hole diameter that is smaller than the diameter of the externally threaded stem of the leveling glide.