Abstract: A retaining plate is provided for use in the assembly of a chair to couple a J-back to a tilt mechanism. The J-back is provided with a number of mounting holes. Similarly, the tilt mechanism is provided with a number mounting holes that can be aligned with the mounting holes in the J-back. The retaining plate has a number of mounting holes disposed therethrough that are located to align with the mounting holes of the J-back and the tilt mechanism. The plate also includes a nut-retaining wall that is formed around the mounting holes and that is dimensioned to hold a threaded nut. The plate has a mechanism that is used to couple the plate to the tilt mechanism. In use, nuts may be placed within and held by the nut-retaining wall, and the plate may be coupled to the tilt mechanism so that the J-back may be coupled to the tilt mechanism by threading bolts into the nuts, the nuts being held in place by the nut-retaining walls.

Abstract: A J-back calibration device is adapted to vary respective positions of the seat and the back on a chair to which it is removedly attached. A chair measurement device is mounted to the seat of the chair and is adapted to take measurements of the chair given a set position of the J-back calibration device. A design of experiments software is provided with test condition information including the variable positions of the J-back calibration device and measurements from the chair measurement device. The software generates a table of configuration settings for the J-back calibration device at which shirt-pull and bridging or other such variable sought to be optimized can be measured and provided to the software. Through graphical and other analytical tools, optimal configuration settings for the variable positions of the J-back calibration device are determined. The J-back of a chair is adapted to these calibrated settings.

Abstract: A retaining plate is provided for use in the assembly of a chair to couple a J-back to a tilt mechanism. The J-back is provided with a number of mounting holes. Similarly, the tilt mechanism is provided with a number mounting holes that can be aligned with the mounting holes in the J-back. The retaining plate has a number of mounting holes disposed therethrough that are located to align with the mounting holes of the J-back and the tilt mechanism. The plate also includes a nut-retaining wall that is formed around the mounting holes and that is dimensioned to hold a threaded nut. The plate has a mechanism that is used to couple the plate to the tilt mechanism. In use, nuts may be placed within and held by the nut-retaining wall, and the plate may be coupled to the tilt mechanism so that the J-back may be coupled to the tilt mechanism by threading bolts into the nuts, the nuts being held in place by the nut-retaining walls.

Abstract: A J-back calibration device is adapted to vary respective positions of the seat and the back on a chair to which it is removedly attached. A chair measurement device is mounted to the seat of the chair and is adapted to take measurements of the chair given a set position of the J-back calibration device. A design of experiments software is provided with test condition information including the variable positions of the J-back calibration device and measurements from the chair measurement device. The software generates a table of configuration settings for the J-back calibration device at which shirt-pull and bridging or other such variable sought to be optimized can be measured and provided to the software. Through graphical and other analytical tools, optimal configuration settings for the variable positions of the J-back calibration device are determined. The J-back of a chair is adapted to these calibrated settings.

Abstract: A chair control mechanism is provided for use on a chair having a separate seat 14 and backrest 16 that move with respect to a base 12 of the chair. The mechanism 22 includes a housing 26 supported on the base, and brackets 28, 30 secured to the seat and backrest. The seat bracket 28 is supported on the housing for pivotal movement about a horizontally extending front pivot axis 68 between an upright position and a reclining position, and the front pivot axis is located adjacent the front end of the housing. The backrest bracket 30 is supported on the housing for pivotal movement about a horizontally extending rear pivot axis 80 that is located rearward of the front pivot axis.

Abstract: In a chair having a base, a seat, a backrest, and a tilt control mechanism, a horizontal adjustment mechanism is provided for allowing fore and aft shifting movement of the seat relative to the backrest. The tilt control mechanism typically includes a pair of rails or other mounting structure by which the control mechanism is normally fastened to the seat. The rails present a pair of laterally spaced longitudinally extending edges and a plurality of mounting holes arranged in a predetermined pattern. The horizontal adjustment mechanism includes a seat mounting assembly provided with a pair of laterally spaced guides adapted to engage the edges of the rails to support the seat mounting assembly for sliding movement on the control mechanism.

Abstract: A chair control mechanism is provided for use on a chair having a separate seat 14 and backrest 16 that move with respect to a base 12 of the chair. The mechanism 22 includes a housing 26 supported on the base, and brackets 28, 30 secured to the seat and backrest. The seat bracket 28 is supported on the housing for pivotal movement about a horizontally extending front pivot axis 68 between an upright position and a reclining position, and the front pivot axis is located adjacent the front end of the housing. The backrest bracket 30 is supported on the housing for pivotal movement about a horizontally extending rear pivot axis 80 that is located rearward of the front pivot axis.

Abstract: A chair control mechanism is provided for use on a chair having a separate seat 14 and backrest 16 that move with respect to a base 12 of the chair. The mechanism 22 includes a housing 26 supported on the base, and brackets 28, 30 secured to the seat and backrest. The seat bracket 28 is supported on the housing for pivotal movement about a horizontally extending front pivot axis 68 between an upright position and a reclining position, and the front pivot axis is located adjacent the front end of the housing. The backrest bracket 30 is supported on the housing for pivotal movement about a horizontally extending rear pivot axis 80 that is located rearward of the front pivot axis.

Abstract: A low profile knee-tilt chair control for controlling biased tilting between a chair seat plate and a chair base plate of a pedestal base chair wherein the chair base plate is supported by a single vertical spindle at the rear of the base plate, and the chair seat plate pivots about a horizontal axis at the front of the base plate. The chair seat is biased to an at-rest position by a low profile, conical helical compression spring operable between the base plate and chair seat and located between the spindle and the horizontal pivot axis of the base plate. The low profile, conical helical compression spring is so mounted relative to the base plate and chair seat plate that the small coils of the compression spring may pass through the large coils during compression of the spring. The control is further characterized by a lockout for securing the chair seat plate against tilting relative to the base plate in either of two different, selectable, at-rest positions.