Tiltable swivel chair

Claim 2

In a tiltable swivel chair, pivot means adapted to be fixed to a seat of the chair at the underside of said seat, housing means supporting said pivot means for tilting movement about a predetermined horizontal tilt axis rearwardly from and forwardly toward a given forward end position, support means supporting said housing means for rotary movement about a vertical swivel axis perpendicular to said tilt axis, springy compression washer means situated in said housing means, mounting means for mounting said compression washer means for compression and expansion along a horizontal spring axis perpendicular to said tilt axis, and transmission means engaging said compression washer means for transmitting tilting of said pivot means about said tilt axis to said compression washer means for compressing the latter horizontally to an increasing extent as said pivot means is tilted rearwardly away from said forward end position, said compression washer means acting through said transmission means on said pivot means for urging the latter forwardly toward said forward end position, said compression washer means including a series of compression washers arranged back-to-back in groups of two, said mounting means including an elongated rod extending through the series of compression washers, and adjusting means coacting with said rod for adjusting the longitudinal position thereof in said housing means to adjust said compression washer means, said adjusting means including an end portion of said rod which is of a diameter larger than the remainder of the rod and has an inner end surface engaging an end washer, said end portion being externally threaded and having an outer end surface accessible at the exterior of said housing means and a nut carried by said housing and surrounding and engaging the threads of said end portion of said rod so that turning of the latter with respect to said nut will adjust the longitudinal position of said rod.

Claim 3

The combination of claim 1 and wherein said traNsmission means includes a pair of pins carried by said pivot means for swinging movement therewith about said tilt axis and extending to opposite sides of said rod, respectively, the latter extending between said pins and said pins engaging an end washer of the series of compression washers distant from said nut, said housing having a stationary surface engaging said pivot means to determine an end position of the seat.

Claim 4

The combination of claim 2 and wherein said tilt axis is situated above said spring axis.

Claim 5

In a tiltable swivel chair, pivot means adapted to be fixed to a seat of the chair at the underside of said seat, housing means supporting said pivot means for tilting movement about a predetermined horizontal tilt axis rearwardly from and forwardly toward a given forward end position, support means supporting said housing means for rotary movement about a vertical swivel axis perpendicular to said tilt axis, springy compression washer means situated in said housing means, mounting means for mounting said compression washer means for compression and expansion along a horizontal spring axis perpendicular to said tilt axis, and transmission means engaging said compression washer means for transmitting tilting of said pivot means about said tilt axis to said compression washer means for compressing the latter horizontally to an increasing extent as said pivot means is tilted rearwardly away from said forward end position, said compression washer means acting through said transmission means on said pivot means for urging the latter forwardly toward said forward end position, said compression washer means including a series of compression washers arranged back-to-back in groups of two, said mounting means including an elongated rod extending through the series of compression washers, and adjusting means coacting with said rod for adjusting the longitudinal position thereof in said housing means to adjust said compression washer means, said adjusting means including an end portion of said rod which is externally threaded and which has end face accessible at the exterior of said housing means and a nut carried by said housing and surrounding and engaging the threads of said end portion of said rod so that turning of the latter with respect to said nut will adjust the longitudinal position of said rod, said transmission means including a pair of pins carried by said pivot means for swinging movement therewith about said tilt axis and extending to opposite sides of said rod, respectively, the latter extending between said pins and said pins engaging an end washer of the series of compression washers, said housing having a stationary surface engaging said pivot means to determine an end position of the seat, said housing means being of a tubular configuration coaxially surrounding said swivel axis and including a tubular extension surrounding said spring axis and accommodating at least some of the compression washers in its interior.

Claim 6

In a tiltable swivel chair, pivot means adapted to be fixed to a seat of the chair at the underside of said seat, housing means supporting said pivot means for tilting movement about a predetermined horizontal tilt axis rearwardly from and forwardly toward a given forward end position, support means supporting said housing means for rotary movement about a vertical swivel axis perpendicular to said tilt axis, springy compression washer means situated in said housing means, mounting means for mounting said compression washer means for compression and expansion along a horizontal spring axis perpendicular to said tilt axis, and transmission means engaging said compression washer means for transmitting tilting of said pivot means about said tilt axis to said compression washer means for compressing the latter horizontally to an increasing extent as said pivot means is tilted rearwardly away from said forward end position, said compression washer means acting through said transmission means on said pivot means for urging the latter forwardly toward said forward end position, said compression washer means including a series of compression washers arranged back-to-back in groups of two, said mounting means including an elongated rod extending through the series of compression washers, and adjusting means coacting with said rod for adjusting the longitudinal position thereof in said housing means to adjust said compression washer means, said adjusting means including an end portion of said rod which is externally threaded and which has end face accessible at the exterior of said housing means and a nut carried by said housing and surrounding and engaging the threads of said end portion of said rod so that turning of the latter with respect to said nut will adjust the longitudinal position of said rod, said transmission means including a pair of pins carried by said pivot means for swinging movement therewith about said tilt axis and extending to opposite sides of said rod, respectively, the latter extending between said pins and said pins engaging an end washer of the series of compression washers, said housing having a stationary surface engaging said pivot means to determine an end position of the seat, said housing means being of a tubular configuration coaxially surrounding said swivel axis and including a tubular extension surrounding said spring axis and accommodating at least some of the compression washers in its interior.

Claim 7

The combination of claim 4 and wherein said tubular extension fixedly carries said nut at the region of a free end of said tubular extension.

Claim 8

In a tiltable swivel chair, pivot means adapted to be fixed to a seat of the chair at the underside of said seat, housing means supporting said pivot means for tilting movement about a predetermined tilt axis rearwardly from and forwardly toward a given forward end position, support means supporting said housing means for rotary movement about a swivel axis perpendicular to said tilt axis, springy compression washer means situated in said housing means, mounting means for mounting said compression washer means for compression and expansion along a spring axis perpendicular to said tilt axis, and transmission means engaging said compression washer means for transmitting tilting of said pivot means about said tilt axis to said compression washer means for compressing the latter to an increasing extent as said pivot means is tilted rearwardly away from said forward end position, saiD compression washer means acting through said transmission means on said pivot means for urging the latter forwardly toward said forward end position, said housing means including at an upper region a pair of opposed upstanding wall portions extending across said tilt axis and between which said pivot means is located, said pivot means including a pivot head having a bottom surface directed toward said compression washer means, and said housing means having an upper end surface situated beneath said bottom surface of said pivot head for engaging the latter to determine said forward end position.

Claim 9

In a tiltable swivel chair, pivot means adapted to be fixed to a seat of the chair at the underside of said seat, housing means supporting said pivot means for tilting movement about a predetermined tilt axis rearwardly from and forwardly toward a given forward end position, support means supporting said housing means for rotary movement about a swivel axis perpendicular to said tilt axis, springy compression washer means situated in said housing means, mounting means for mounting said compression washer means for compression and expansion along a spring axis perpendicular to said tilt axis, and transmission means engaging said compression washer means for transmitting tilting of said pivot means about said tilt axis to said compression washer means for compressing the latter to an increasing extent as said pivot means is tilted rearwardly away from said forward end position, saiD compression washer means acting through said transmission means on said pivot means for urging the latter forwardly toward said forward end position, said housing means including at an upper region a pair of opposed upstanding wall portions extending across said tilt axis and between which said pivot means is located, said pivot means including a pivot head having a bottom surface directed toward said compression washer means, and said housing means having an upper end surface situated beneath said bottom surface of said pivot head for engaging the latter to determine said forward end position.

Claim 10

The combination of claim 6 and wherein said swivel axis and spring axis are substantially parallel to each other.

Claim 11

The combination of claim 7 and wherein said mounting means includes an elongated rod extending downwardly from said pivot means along the interior of said housing means.

Claim 12

The combination of claim 8 and wherein said compression washer means includes a series of compression washers arranged back-to-back in groups of two, said rod extending through said series of compression washers, and said transmission means including a pair of pins fixedly carried by said housing in the interior thereof over said washers, said pins extending across said rod and the latter extending freely through a space defined between said pins, the upper end of the series of compression washers engaging said pins.

Claim 13

The combination of claim 9 and wherein said rod threadedly carries at its bottom end portion a nut engaging the lower end of the series of compression washers and forming an adjusting means for adjusting said washers.

Claim 14

The combination of claim 10 and wherein said pivot means is pivotally connected with said rod at an upper end thereof so that when said pivot means swings about said tilt axis said rod is pulled upwardly with respect to said pins of said transmission means for compressing the washers between said pins and said nut.