Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS2818911 A
Publication typeGrant
Publication date7 Jan 1958
Filing date5 Nov 1954
Priority date5 Nov 1954
Publication numberUS 2818911 A, US 2818911A, US-A-2818911, US2818911 A, US2818911A
InventorsCharles W Syak
Original AssigneeTrumbull Dev Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Tiltable office chair
US 2818911 A
Abstract  available in
Images(1)
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

Jan. 7, 1958 c. w. SYAK 2,818,911

TILTABLE OFFICE CHAIR Filed Nov. 5, 1954 K FIG! INVENTOR. CHARLES w SYAK A TIQRNE Y United States Patent TILTABLE OFFICE CHAIR Charles W. Syak, Girard, Ohio, assignor to Trumbull Development Corporation, Girard, Ohio, a corporation of Ohio Application November 5, 1954, Serial No. 467,086

2 Claims. (Cl. 155-77) This invention relates to a chair iron and more particularly to an improved chair iron for use with tiltable oflice chairs and the like.

The principal object of the invention is the provision of an improved chair iron for an ofiice chair incorporating a swiveling and adjustable tilting mechanism.

A further object of the invention is the provision of an improved chair iron incorporating novel means for actuating and adjusting the tilting movement of a chair.

A still further object of the invention is the provision of an improved chair iron for a tiltable swivel chair which requires fewer moving parts and a less expensive structure to obtain an improved tilting action and noiseless tilting and moving.

A still further object of the invention is the provision of a chair iron which may be universally used in the chair industry for mounting a chair in a tilting swiveling relation on a base.

A still further object of the invention is the provision of a chair iron in which the weight of the chair and occupant thereof is concentrated downwardly at the pivotal point and opposed by a straight leaf spring mounted in the chair iron and positioned over an adjustable fulcrum, longitudinally of said spring.

A still further object of the invention is the provision of a chair iron for a tiltable swivel chair incorporating a straight leaf spring arranged to be activated by a bending action when the chair is tilted and wherein the pivotal point is so located in relation to the supporting spindle and base that upon tilting, the center of gravity moves forward and results in a decreased return thrust on the part of the spring even though the same is under greater load tension.

A still further object of the invention is the provision of a chair iron for a tilting swivel chair which will allow the occupant to tilt backward to a certain degree without eiiort and return without effort while at the same time not be thrust forward by the spring mechanism in the chair iron.

The chair iron disclosed herein comprises an improvement in the art of tilting swivel constructions as used primarily in oliice chairs and which have generally heretofore comprised tiltable structures opposed by coil springs acting to uniformly resist the tilting of the chair with respect to the base supporting the same.

The improved chair irondiffers in structure and action from such leaf spring opposed chair iron constructions as have heretofore been known in that tilting action of the chair with respect to the swivel and base supporting the same is directly received by the free end of a leaf spring which is engaged upon a movable fulcrum member intermediate the ends of the spring, and which movable fulcrum is located forwardly of the pivotal point of the chair iron while said pivotal point is located forwardly of the swivel mechanism and supporting base.

In the improved chair iron, the tiltable portion of the chair iron includes a roller on a supporting stem engaging the free end of the leaf spring and movable therealong in slight degree as the chair is tilted.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being the intention to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

The invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a front elevation of a chair incorporating the k improved chair iron.

Figure 2 is a side elevation of the chair illustrated in Figure 1 with broken line showing the tilted position of the chair.

Figure 3 is an enlarged vertical section taken on line 33 of Figure 1.

Figure 4 is a cross section similar to that of Figure 3 showing the chair in tilted position.

Figure 5 is an enlarged detail taken on line 55 of Figure 3 illustrating a silencing washer disposed between the movable portions of the chair iro-n.

By referring to the drawings and Figures 1 and 2 in particular it will be seen that achair base 10 having a plurality of casters 11 thereon supports a central spindle 12, the upper end of which rotatably supports an apertured cup-shaped depending portion 13 of a housing 14 which includes a section extending horizontally forwardly from the cup-shaped portion 13 with oppositely disposed spaced side walls 15 joined by a front wall 16. The upper edge of the front wall 16 is tapered outwardly and inturned as at 17 and is provided with a rubber stop pad 18. The side walls 15 taper downwardly toward the rear and are apertured on a common transverse line to receive pivot members 19.

The areas of the side walls 15 about the pivot members 19 are embossed inwardly on their outer surfaces as indicated by the numerals 20 to receive and retain nylon washers 21 which space the side walls 15 of the housing 14 with respect to downturned space-d flanges of a chair spider 22, which downturned flanges lie on spaced parallalel planes with respect the side walls 15 of the hous ing The pivot members 19 join the side walls 15 of the housing 14 and the downturned flanges of the chair spider 22, as best shown in Figure 5 of the drawings. The chair spider 22 is of conventional construction and supports the chair thereon including a seat 23, arms 24 and back 25. The sides of the seat 23 may be flanged downwardly if desired so as to hide the chair iron.

The pivot members 19 will thus be seen to pivotally mount the chair spider 22 and the chair thereon in pivotal relation to the housing 14 and it will be observed by referring to Figures 3 and 4 of the drawings that the pivot members 19 are located forwardly of the spindle 12.

The downturned flanges on the sides of the chair spider 22 carry a transversely positioned support rod 26 therebetween whichhas a roller 27 thereon. The rod 26 is attached to the downturned flanges of the chair spider 22 at a point rearwardly of the spindle 12 and on the opposite side thereof with respect to the pivot members 19.

The front wall 16 of the housing 14, and more particularly the outwardly tapered portion thereof, carries an angular bracket 28 on its inner surface which is secured thereto by fasteners 29, the lower end of the angular bracket 28 extending inwardly of the housing 14 on a substantially horizontal plane and has one end of a leaf spring 3%) secured thereto as by fasteners 31. The leaf spring 30 extends backwardly within the housing 14 and near its free end, engages the lower portion of the roller 27.

The vertical portion of the front wall 16 of the housing 14 is apertured and carries an adjusting screw 32 through said aperture. The adjusting screw 32 is retained in horizontal position in the housing 14 by a collar 33 positioned on the forward side of the front wall 16 of the housing 14 and extending between the front wall 16 and an adjustment cap or wheel 34 which is secured to the extending end of the adjusting screw 32.

A retaining pin 35 affixed transversely of the adjusting screw 32 engages against a washer 36 on the inner side of the front wall 16 of the housing 14 to secure the adjusting screw 32 in rotatable horizontal position in the housing 14. A cross sectionally triangular fulcrum member 37 is positioned in the housing 14 on the horizontal portion thereof forwardly of the spindle 12 and is provided with a threaded section 38 engaged on the threaded adjustment screw 32. Thus, rotation of the adjustment cap or wheel 34 will revolve the adjusting screw 32 and move the fulcrum member 37 longitudinally in the housing 14 and longitudinally of the leaf spring 3i). The fulcrum member 37 is thus supported on the housing 14 with its uppermost portion or apex engaging the lower surface of the leaf spring 30 between the ends thereof. By moving the fulcrum member 37 beneath the leaf spring 30, varying degrees of spring resistance to the tilting motion of the chair may be realized, as the spring is in effect lengthened or shortened thereby.

It will be observed that the free end of the leaf spring 30, which is engaged by the roller 27, is at all times freely movable in an arc based on the fulcrum 37 as modified by the attachment of the opposite end of theleaf spring 30 to the front wall 16 of the housing 14.

The action obtained is illustrated in Figure 3 of the drawings showing the chair in upright horizontal position and the fulcrum member 37 positioned well forward in the housing 14, while in Figure 4 of the drawings a broken line illustrates the fulcrum member 37 as positioned inwardly of the housing 14 adjacent the spindle 12 and a broken line illustrates the alternate positioning of the leaf spring 30 under such conditions, it being observed that a cantilever springing action is obtained.

It will thus be seen that the tilting mechanism of the chair iron is adjustable so that the downward and return thrust on the leaf spring may vary to a greater or lesser degree depending upon the weight of the individual in the chair. ward to a certain degree without effort and to be able to return to horizontal or upright position without effort while not being thrust forwardly or backwardly with a rapid motion.

The chair iron is so designed that in the event of spring failure, the chair spider 22 will engage the housing 14 and more particularly the side walls 15 thereof, at points adjacent the roller 27 as defined by the rubber pads 39. It will be seen that the utilization of the movable fulcrum 37 with the leaf spring secured only at its forward end results in a longer or shorter lever arm and consequently the forward and return thrust may be increased or decreased.

It will also be observed that the roller 27 is so located that upon assembly, a slight downward tension is applied to the free end of the leaf spring 30. It will be noted. that when the chair is tilted backward, as shown in Figure 4 of the drawings, the leaf spring 30 is activated This action allows the occupant to tilt backby a bending action which in turn provides a return thrust, the pivotal members 19 being located forwardly of the spindle 12 so that upon tilting, the center of gravity moves forward and, therefore, at a given location or a fixed point of tilt the return thrust is lessened even though the leaf load is under greater tension. This feature is desirable since the tilting mechanism must have a certain build up of thrust and yet not have the tendency upon tilting backward to urge the chair occupant forward.

It will thus be seen that the several objects of the invention are met by the chair iron disclosed herein.

Having thus described my invention, what I claim is: 1. A chair iron for a tiltable swivel chair comprising a housing mounted on a spindle and a chair spider having depending portions pivotally secured to said housing, said housing comprising an elongated horizontally disposed member having spaced vertical side walls and a front wall joining said vertical side walls, and means forming said pivotal mounting comprising pivot mem-' bers engaging depending portions of said chair spider and said side walls and located rearwardly of said front wall of said housing and forwardly of said spindle, the top edges of said side walls inclining downwardly and rearwardly of said pivotal members, a bracket secured to said front wall and extending inwardly of said housing on a horizontal plane, and a leaf spring one end of which is secured to said bracket and extending longitudinally of said housing in spaced relation to the top of said chair spider and the bottom of said housing, a support rod on said chair spider between said depending portions thereof, a roller on said support rod engaging said leaf spring adjacent the free end thereof, a fulcrum member disposed in said housing between the front wall thereof and said spindle and movable therebetween, and a threaded screw rotatably positioned in said housing and threadably engaged in said fulcrum member for moving the same, the fulcrum member engaging the bottom of said leaf spring between said pivotal members and said front wall, said support rod and roller being located rearwardly of said spindle.

2. A chair iron for a tiltable swivel chair comprising an elongated member having spaced vertical side walls, an upwardly and outwardly inclined front wall at one end and an apertured cup-shaped depending portion near its opposite end, said elongated member mounted on a spindle engaging said apertured cup-shaped portion, a chair spider having depending portions pivotally secured to said side walls by pivot members forwardly of said cup-shaped portion, a leaf spring, one end of which is attached to said inclined front wall and the remainder of which extends inwardly therefrom on a normal horizontal plane in spaced relation to said elongated member and spider, a support rod on said spider above said spring, a roller on said rod engaging said spring inwardly from the free end thereof and rearwardly of said spindle, a fulcrum member positioned on said elongated member for longitudinal movement with respect thereto and means for moving said fulcrum member, said ful crum member engaging the bottom of said leaf spring between said pivotal members and said inclined front wall.

References Cited in the file of this patent UNITED STATES PATENTS l44,349 Morrison Nov. 4, 1873 2,339,953 Schlorman Jan. 25, 1944 2,440,172 Gibbons Apr. 20, 1948 2,478,112 Larsen Aug. 2, 1949

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US144349 *29 Sep 18734 Nov 1873 Improvement in chairs
US2339953 *20 Oct 194225 Jan 1944Herman SchlormanTilt back swivel chair
US2440172 *9 Oct 194520 Apr 1948Thomas GibbonsHobbyhorse
US2478112 *20 Jul 19442 Aug 1949Heywood Wakefield CoAdjustable rocking chair
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3203661 *13 Jul 196231 Aug 1965Friedrich BrendelSeat support
US3241880 *31 Mar 196422 Mar 1966WilliamsAdjustable chair
US3278228 *3 Jan 196611 Oct 1966Doerner Products Co LtdChair control pressure plate having replaceable thrust bearings
US3290091 *14 Jan 19666 Dec 1966Goodman RobertChairs with tiltable portions
US3352526 *2 Nov 196514 Nov 1967Collier Keyworth CompanyChair iron
US3368844 *17 Oct 196613 Feb 1968Doerner Products Co LtdChair control for tilting and swivel chairs having improved tensioning bolt
US3369840 *22 Jul 196620 Feb 1968Dare Inglis Products LtdChair tilting mechanism
US3693925 *4 Nov 197026 Sep 1972Daniel WeinsteinTilting chair mechanism
US3814369 *28 Oct 19714 Jun 1974Kastholm JTiltable swivel chair
US4076308 *19 May 197728 Feb 1978Wilkhahn, Wilkening & HahneChair
US4077596 *18 Jun 19757 Mar 1978Bliss & Laughlin Industries, IncorporatedLow silhouette chair tilting control assembly
US4214726 *6 Nov 197829 Jul 1980Steelcase, Inc.Chair control
US4736984 *31 Oct 198612 Apr 1988Super Sagless CorporationPivot assembly for reclining chair with rocking feature
US4889384 *10 Jul 198826 Dec 1989Leggett & Platt, IncorporatedKnee-action chair control
US5026117 *18 Jul 198925 Jun 1991Steelcase Inc.Controller for seating and the like
US5042876 *25 Jul 198927 Aug 1991Steelcase Inc.Controller for seating and the like
US5080318 *19 Jun 199014 Jan 1992Itoki Kosakusho Co., Ltd.Tilting control assembly for chair
US5160184 *6 Mar 19913 Nov 1992Steelcase, Inc.Controller for seating and the like
US617654823 Oct 199823 Jan 2001Haworth, Inc.Tilt mechanism for chair having adjustable spring characteristics
US620995823 Oct 19983 Apr 2001Haworth, Inc.Universal tilt mechanism for a chair
US625071520 Jan 199926 Jun 2001Herman Miller, Inc.Chair
US636787611 Apr 20019 Apr 2002Herman Miller, Inc.Chair
US658201915 Mar 200124 Jun 2003Herman Miller, Inc.Tilt assembly for a chair
US681766816 May 200316 Nov 2004Steelcase Development CorporationSeating unit with variable back stop and seat bias
US686914212 Sep 200222 Mar 2005Steelcase Development CorporationSeating unit having motion control
US68808865 Jun 200319 Apr 2005Steelcase Development CorporationCombined tension and back stop function for seating unit
US695786313 Sep 200425 Oct 2005Steelcase Development CorporationSeating unit having motion control
US69912911 Feb 200531 Jan 2006Steelcase Development CorporationBack construction for seating unit having spring bias
US700454324 Aug 200428 Feb 2006Herman Miller, Inc.Chair
US70407091 Feb 20059 May 2006Steelcase Development CorporationBack construction for seating unit having inverted U-shaped frame
US704071118 Dec 20039 May 2006Steelcase Development CorporationNonslip bearing arrangement
US711477721 Sep 20043 Oct 2006Steelcase Development CorporationChair having reclineable back and movable seat
US71317001 Feb 20057 Nov 2006Steelcase Development CorporationBack construction for seating unit
US71658115 Jun 200323 Jan 2007Steelcase Development CorporationControl mechanism for seating unit
US723477423 Sep 200526 Jun 2007Steelcase Development CorporationSeating unit with novel flexible supports
US72378411 Feb 20053 Jul 2007Steelcase Development CorporationBack construction with flexible lumbar
US7261368 *27 Feb 200628 Aug 2007Todd ClausnitzerErgonomic chair
US742710518 Sep 200623 Sep 2008Steelcase Inc.Back construction for seating unit
US7434880 *22 Dec 200314 Oct 2008Varier Furniture AsMobile joint suitable for a sitting device
US745863710 Jun 20042 Dec 2008Steelcase Inc.Back construction with flexible lumbar
US75404654 Oct 20052 Jun 2009Miller Charles AShock absorbing motor mount for vibratory belt drive
US7753447 *12 Oct 200713 Jul 2010L&P Property Management CompanyCasual control tilt lockout
US7806478 *4 Jan 20075 Oct 2010Sava CvekTask chair with dual tilting capabilities
US785739022 Mar 200728 Dec 2010Herman Miller, Inc.Piece of furniture
US799293717 Sep 20089 Aug 2011Herman Miller, Inc.Body support structure
US8025334 *2 Dec 201027 Sep 2011Herman Miller, Inc.Piece of furniture
US826216211 Apr 201111 Sep 2012Herman Miller, Inc.Biasing mechanism for a seating structure and methods for the use thereof
US8540519 *6 Dec 201024 Sep 2013James LauterSeated balancing device
EP0434897A1 *22 Jun 19903 Jul 1991Itoki Crebio CorporationTilting control assembly for chair
WO2013020088A2 *3 Aug 20127 Feb 2013Cramer LlcErgonomic seating assemblies and methods
Classifications
U.S. Classification248/575, 297/303.1, 297/302.5, 248/596, 297/302.1, 248/626
International ClassificationA47C3/026
Cooperative ClassificationA47C7/441, A47C7/445, A47C3/026
European ClassificationA47C7/44A, A47C7/44F, A47C3/026