Abstract: An armrest construction for chairs includes an armrest support having a lower end constructed for attachment to a chair, an upper end, and a mounting block attached to the upper end. A pivot block is pivoted to the mounting block at a main pivot, the pivot block having an upwardly-extending follower. First and second gears are each pivoted to the pivot block, the gears having intermeshing teeth at an inner end such that rotation of the first gear causes the second gear to simultaneously rotate in an opposite direction, the first and second gears further having outer ends. A support plate having pivot/slide members engages the outer ends of the first and second gears, and further has a guide operably engaging the follower to guide lateral movement of the support plate along a predetermined path.

Abstract: A task chair is provided having a base frame, a back assembly pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base assembly and pivoted to the back frame so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. The pivots for connecting the back frame to the base frame and for connecting the seat to the back frame permit quick fastenerless assembly by flexing the back frame during assembly. The pivots include rubber elements that permit flexing of a bearing element to prevent binding during rotation when the bearing element is not fully aligned with a pivot axis. A method of assembly including flexing apart the configured end sections of the back frame positioning the configured ends adjacent opposite sides of the seat, and releasing the configured end sections so that they engage the seat, is also disclosed.

Abstract: A chair is provided having a base assembly, a back frame pivoted to the base assembly for movement between upright and reclined positions, and a seat slidably supported on the base frame and pivoted to the back assembly so that the seat moves forwardly and its rear moves forwardly and downwardly with the back frame upon recline. A flexible back is connected to the back frame at top and bottom locations and is provided with lumbar adjustment for improved lumbar force/support and shape. A seat is provided with seat depth adjustment and with active and passive thigh flex support. The seat includes a front section adjustably and/or flexibly supported on a rear section for optimal comfort while supporting a seated adult user's thighs, with the rear section being configured to carry a majority of the weight of a typical seated adult user. A novel energy mechanism is provided that includes a moment arm shift adjuster for adjusting the spring tension on the back frame.

Abstract: An adjustment mechanism for adjusting the height of a chair seat, table top or the relative position of other items includes an outer support tube and a telescoping, column tube subassembly. The column tube subassembly includes an inner support tube, a cylinder and a piston and piston rod subassembly. The piston rod is connected to the piston at one end and to the outer support tube at the other end. An elastomeric sleeve surrounds the cylinder. A valve controls flow of hydraulic fluid from the interior of the cylinder to and from an expandable chamber defined by the elastomeric sleeve. The piston snap-fits onto the piston rod and allows rotation of the column tube subassembly with respect to the outer support tube. A shock-absorbing element is disposed in the cylinder.

Abstract: A laterally adjustable armrest assembly for a chair includes an armrest support adapted to be secured to the chair. A bracket is joined to an upper end of the armrest support. An armrest member defines a plurality of downwardly opening grooves dimensioned to receive the bracket in selectively adjustable lateral positions.

Abstract: A chair back height adjustment mechanism includes an inner, generally rectangular bracket defining a pair of laterally spaced sockets adapted to receive a pair of chair back supports. An inner shell defines a plurality of guides which receive glides or tabs formed on the bracket. The bracket defines a rack portion facing the inner shell. A release handle is pivotally mounted on the inner shell. The handle defines teeth engageable with the rack portion of the bracket.

Abstract: An arm height adjustment mechanism for a chair of the type having a pair of laterally spaced, fixed armrest supports. The mechanism includes first and second armrests slidably mounted on said supports for vertical movements. A vertical motion translation mechanism interconnects said armrests so that vertical movement of one armrest translates to synchronized, simultaneous vertical movement of the other armrest.