Abstract: A chair having a recline control mechanism, a limit control apparatus and a tilt mechanism. The recline control mechanism operates to adjust resistance to rotation of a back assembly of the chair and includes an actuator lever having a lock structure attached to a movable spring assembly. Moving the spring assembly toward and away from a rotation axis for the back assembly adjusts the resistance. The limit control apparatus selectively limits the extent of rotation of the back assembly from about zero degrees to about 3.5 degrees to about seven degrees by using abutment surfaces. The tilt mechanism provides an independent and stable yet passive tilt capability to a backrest of the back assembly by using a pair of brackets, two pairs of links and two pairs of rods.

Abstract: A horizontally adjustable armrest for a chair including a vertically slideable element having a base, a lower horizontal slide element movable longitudinally, an upper horizontal slide element movable laterally and an armrest cover. The lower horizontal slide element includes a longitudinally extending slot with a shoulder. Two fasteners extend through the slot and are fastened to the base. Under the fasteners' heads are springs and washers to bias the lower slide element into frictional engagement with the base. The upper surface of the lower horizontal slide element includes a pair of guide rails which are received in recesses formed in the bottom surface of the upper horizontal slide element. The upper slide element includes two slots extending perpendicular to the slot of the lower slide element. Fasteners, springs and washers are used to bias the upper slide element into frictional engagement with the lower slide element. An armrest cover fits over the horizontal slide elements.

Abstract: A chair having a seat and a back rest comprises a fluid-containing cushion in the back rest that provides passive automatically adjustable support for the user's lumbar region. The cushion can comprise one or more fluid-containing chambers encompassing the areas of the user's upper back and lumbar regions. As the user leans backs, fluid is forced from the regions adjacent the upper back down to the lumbar region to provide enhanced lumbar support to the user.

Abstract: A chair with backward and forward passive tilt capabilities including a seat assembly, a back assembly, a frame assembly, a wheeled base, a pedestal and a tilt mechanism. The tilt mechanism includes first, second and third links, first, second, third and fourth pivot pins, brackets and a resilient deformable block. The first link connects the back assembly with the frame assembly by way of the first pivot pin and the seat assembly by way of the second pivot pin. The second link connects to the frame assembly with the third pivot pin and to the third link with the fourth pivot pin. When a chair occupant shifts his/her weight rearwardly to tilt the back assembly, the seat assembly lifts and the block is deformed and stressed. When the chair occupant leans forwardly, the seat assembly lowers and the back assembly tilts forwardly. Again, the block deforms. Once the occupant sits upright or leaves the chair, the deformed block induces a return force to place the chair in a neutral upright position.

Abstract: A vertically adjustable armrest assembly having a support, a plate fitted to an interior of said support, the plate having a series of vertically aligned openings, a slide having an armrest at a top end portion, and a lateral slot for guiding a block into and out of selective aligned openings in the plate. A rod having a saw tooth portion complementing a slanted opening in the block allows manipulation of the rod to selectively move the block into and out of the plate openings.

Abstract: A chair has a seat that can be longitudinally repositioned by the user while the user is seated on the chair, so as to accommodate users of different heights and physical dimensions. The chair includes a base, a seat slidable mounted on a seat plate, and activating arm that operates on lock means that engage the seat plate to secure the seat in a preferred longitudinal position relative to the seat plate.

Abstract: A back for a chair includes fabric panel with a flexible carrier attached to the panel around its periphery. The carrier is configured to be secured along a bottom edge to a bottom portion of a chair back frame member. The carrier is also secured to two vertical frame supports at its two upper corners. Preferably, the upper carrier and frame connections are ball and socket joints. A lumbar support is provided that is easily height adjustable, by providing tension to the back frame and requires no screws or adjustment knobs in its adjustment mechanism.

Abstract: An adjustable chair seat with a locking mechanism that is torque limiting and resistant to loosening. The chair includes a seat pan, a seat plate, a rotatable fastener and two rings. The seat pan and seat plate have openings for receiving the fastener. The fastener includes a cup handle and a threaded insert. The threaded insert is engaged with the seat pan through an opening in the seat pan while the seat plate is sandwiched between the seat pan and the fastener. When being rotated, the cup handle slips relative to the threaded insert after a predetermined resistance is reached so as to cease the application of torque to the threaded insert. One of the rings is keyed to rotate with the fastener and the other ring is keyed to remain non-rotatable. The first ring includes an array of cantilevered teeth where each tooth has a first surface disposed at a smaller angle from a horizontal reference plane and a second surface which is disposed at a greater angle from the horizontal reference plane.