Suche Bilder Maps Play YouTube News Gmail Drive Mehr »
Nutzer von Screenreadern: Klicke auf diesen Link, um die Bedienungshilfen zu aktivieren. Dieser Modus bietet die gleichen Grundfunktionen, funktioniert aber besser mit deinem Reader.


  1. Erweiterte Patentsuche
VeröffentlichungsnummerUS3381926 A
Veröffentlichungsdatum7. Mai 1968
Eingetragen20. Okt. 1966
Prioritätsdatum20. Okt. 1966
VeröffentlichungsnummerUS 3381926 A, US 3381926A, US-A-3381926, US3381926 A, US3381926A
ErfinderFritz Edward E, Fritz Thomas A
Ursprünglich BevollmächtigterEdward E. Fritz, Thomas A. Fritz
Zitat exportierenBiBTeX, EndNote, RefMan
Externe Links: USPTO, USPTO-Zuordnung, Espacenet
Adjustable stool
US 3381926 A
Zusammenfassung  auf verfügbar
Previous page
Next page
Ansprüche  auf verfügbar
Beschreibung  (OCR-Text kann Fehler enthalten)

May 7, i968 E. E. FRITZ ETAL 3,381,925


INVENTORS ammo E. FR/ rz flic/*Ms H. Fm r2 United States Patent O 3,381,926 ADJUSTABLE STOOL Edward E. Fritz, 201 Fernwood Drive, and Thomas A. Fi7tz, 221 Fernvvood Drive, both of Evansville, Ind. 4 11 Filed Oct. 20, 1966, Ser. No. 588,226 5 Claims. (Cl. 248-404) The present invention relates to an adjustable stool, and more particularly to a new and novel mechanism for controlling the height of the stool seat.

As is known, it is desirable to be able to change the height of a stool seat automatically, particularly in the instance of a stool used by personnel in a medical or dental ofiice. Such ready seat height adjustment results in optimum examination and/or treatment of a patient, as well as a convenience, and even more so when accomplished by foot control, as in the present invention.

By virtue of the invention at hand, the inventors herein have provided a new and novel control mechanism for adjusting the height of a seat forming part of a stool which may have application in a dental or medical oice. The seat of the inventors new and novel adjustable stool is controlled by foot operation, meaning that the users hands are free to work, as well as maintained in a sanitary condition.

Broadly, the inventors control mechanism is operated through a hydraulic arrangement, where, with the opening of a control valve, the seat of the stool moves downwardly because of the weight of a person thereon, or, in the alternative, when unoccupied, moves upwardly due to the compression of a spring which pressures hydraulic fluid by means of a piston. The instant control mechanism is representative of a minimum number of operative components, reecting in manufacturing and maintenance economies, in addition to highly desirable end results.

Accordingly, the principal object of the present invention is to provide a new and novel adjustable stool.

Another object of the present invention is to provide a new and novel control mechanism for adjusting the height of a seat of a stool.

A further and more general object of the present invention is to provide a foot operated control mechanism for adjusting the height of a stool seat which is positive in operation; which is readily manufactured; which requires a minimum number of operative components; which permits operation at a convenience not at all present heretofore; and, which retiects a highly sturdy structural arrangement.

Other objects and a better understanding of the present invention will become more apparent from the following description, taken in conjunction with the accompanying drawing, wherein FIG. 1 is a view in elevation, partly fragmentary, partly in phantom, and partly in vertical section, showing the height operating mechanism for the inventors new and novel adjustable stool; and,

FIG. 2 is a fragmentary bottom view of the lever arrangement for permitting foot control of the mechanism at hand.

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawing and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring now to the figures, the height control mechanism 10 for the inventors new and novel adjustable stool is shown in heavy lines, while the mobile base framework, the seat and a portion of the back are shown in phantom lines, all of the latter being conventional and shown for reasons of total impression clarity. In any event, the aforesaid mobile base framework supports an upstanding centrally disposed outer tube 12 having at opposite ends, and threadedly secured thereto, an upper cap 14 and a lower cap 16, the latter being threadedly positioned to the base framework by a locking member 15. Disposed Within the outer tube 12 and positioned by an abutment on the upper cap 14 and received within an opening in the lower cap 16 is an inner tube 17, the latter positioning a shaft 19 which extends downwardly from the bottom of the stool seat.

An inner piston 20 is disposed at the lower free end of the shaft 19 and is movable therewith, typically including seal members 22, such as O-rings, for example, around the outer surface thereof. An outer piston 30, also including various seal members 32, is disposed in the space between the inner tube 17 and the outer tube 12, where a heavy duty compression member 24, such as a spring, for example, completes the space between the outer piston 30 and the upper cap 14, being seated on such outer piston 30. The relative positioning of the inner piston 20` and the outer piston 30 will be discussed more fully herebelow.

A control Valve 35 is positioned, typically, on the bottom surface of the lower cap 16, being conventional in 'form and permitting selective communication between a longitudinal passageway 16a at one portion of the lower cap 16 and another longitudinal passageway 16b disposed at another portion of the lower cap 16. More specifically, passageway 16a communicates with the space within the inner tube 17 below the inner piston 20, while passageway 16b communicates with the space above the lower cap 16 and below the outer piston 30. For purposes of effective operation, another seal member 16C is employed around the outer surface of the iower cap 16.

The control valve 35 includes a slidable plunger 35a normally urged by spring means (mostly not shown) into the position of FIG. 1, i.e. not permitting any communicatioin between passageways 16a and 16b. In order to afford such communication, when desired, a foot control arrangement is provided comprising one or more foot engaged members 40 extending upwardly from the base, the lower ends of each of which engage control arms 41, the latter being secured to a transverse member 42 positioned on the undersurface of the base by brackets 42a (see FIG. 2).

An actuating member 45 angles downwardly from the transverse member 42, and has a portion thereof which contacts a control button 35b operatively connecting the plunger 35a of the control valve 35. In other words, rby depressing the foot engaged member 40, the control arms 41, and, hence, the transverse member 42, pivot, forcing the control button 35b from right to left in FIG. l through movement of the actuating member 45, and permitting communication between passageways 16a and 16b through a path created within the control valve 35.

In order to control the height of the seat, a hydraulic fluid, such as a lightweight oil, for example, is introduced into the space within the inner tube 17 below the inner piston 20. When the seat of the stool is occupied by a person, and when the foot engaged member 40 is -moved downwardly to permit operation of the control valve 35, the hydraulic fiuid moves downwardly through passageway 16a, the path within the control valve 35, and upwardly through the passageway 16b into the space between the inner tube 17 and the outer tube 12 above the lower cap 16 and below the outer piston 30, causing the outer piston 3() to move upwardly and, hence, to

compress the spring 24. When the user reaches the desired height, the foot engaged member 40 is released to lock the stool seat at such position.

On the other hand, when it is desired to elevate or raise the height of the seat, and with the seat unoccupied, the foot engaged member `40 is depressed to again operate the control valve 35, creating a path between passageways 16a and 16b. In this instance, however, the compressed spring 24 forces the outer piston 30 downwardly and, hence, the hydraulic iluid through passageway 16h, the path within the control valve 35, and through the passageway 16a into the space within the inner tube i7 below the inner piston 20, making the inner piston 20 with its stool seat supporting shaft 19 move upwardly. Again, as soon as the desired height is achieved, such height may be maintained by releasing the foot engaged member 49.

From the preceding, it should lbe apparent that the inventors herein have provided a new and novel approach for controlling the height of a stool. Positive action is guaranteed, and ready use thereof is achievable by the operator. Not only are a minimum number of components utilized, but a sturdy structure is afforded the over-all mechanism.

The adjustable stool described above is, of course, susceptible to various changes within the spirit of the invention. Obviously, other lfoot operated linkage arrangements might be devised, as well as over-all proportioning varied. Thus, the above description should be considered illustrative and not as limiting the scope of the following claims:

We claim:

1. 4A height adjusting mechanism for a stool having a base framework and a seat comprising spaced-apart hol low inner and outer members disposed on said base framework, cap Imembers at opposite ends of said hollow inner and outer members, an inner seat mounting piston slidable within said hollow inner member, an outer piston slidable in the space between said hollow inner member and said hollow outer member, compression means urging said outer piston in a downward direction, cavities containing a liquid in said hollow inner member below said inner piston and in the space between said hollow inner member and said hollow outer member below said outer piston, passageways through said cap member at the lower ends of said hollow inner and outer members communicating with said cavities, and control mechanism selectively permitting communication between said passageways for seat height adjustment.

2. The height adjusting mechanism of claim 1 where said compression means is a spring.

3. The height adjusting mechanism of claim 1 where said control lmechanism is a valve, and where said valve has a movable element to selectively provide a path between said passageways.

4. The height adjusting mechanism of claim 1 where said control mechanism is foot-operated.

5. The height adjusting mechanism of claim 1 where a foot-operated linkage system is provided for said control mechanism comprising a foot-engageable element disposed on said base framework, an intermediate member rotatably mounted on the undersurface of said base framework and having an extending arm driven by said footengageable element, and a power arm on said intermediate member selectively operating said control mechamsm.

References Cited UNITED STATES PATENTS 557,847 4/1896 Mann 248--404 2,237,915 4/1941 Routson 267-34 2,586,442 2/ 1952 Seagren. 2,636,348 4/1953 Murray 10S-147 X 3,143,332 8/1964 Watlington 248-404 3,311,407 3/1967 Horie 297-347 X 3,339,873 9/1967 Hale 248-404 JAMES T. MCCALL, Primary Examiner.

Zitiertes PatentEingetragen Veröffentlichungsdatum Antragsteller Titel
US557847 *11. Dez. 18957. Apr. 1896 Dental chair
US2237915 *28. Okt. 19398. Apr. 1941Lucien R GrussShock absorber
US2586442 *4. März 195019. Febr. 1952Astra Engineering CompanyPneumatic door operating mechanism
US2636348 *15. Aug. 195028. Apr. 1953Murray Aubrey SHydraulic fluid motor lift mechanism
US3143332 *23. Febr. 19624. Aug. 1964Watlington Lee SHydraulic lift support for chair
US3311407 *4. Mai 196528. März 1967Hideharu HorieAutomatic device for operating the seat frame and back support of a hair dressing and beauty treatment chair
US3339873 *21. Okt. 19655. Sept. 1967Dean H HaleStool with vertically movable seat
Referenziert von
Zitiert von PatentEingetragen Veröffentlichungsdatum Antragsteller Titel
US3667621 *20. Okt. 19706. Juni 1972Wisconsin Foundry And MachineFluid power system for a self-contained unloading unit
US3865341 *8. Aug. 197311. Febr. 1975Den Tal Ez Mfg CoDental stool for dentist and dental assistant
US3985388 *11. Aug. 197512. Okt. 1976Uop Inc.Vertically adjustable seat with energy absorbing means
US4061304 *25. Aug. 19766. Dez. 1977Contraves AgSurgical chair for a doctor
US4074887 *20. Sept. 197621. Febr. 1978Hale Dean HPower unit for a medical or like stool
US4415135 *22. März 198215. Nov. 1983Wipac Group Sales LimitedSupport devices for swivel chairs
US4592590 *29. Aug. 19853. Juni 1986Kimball International, Inc.Hydraulic lifting mechanism for a chair or the like using a two phase working fluid
US4593951 *5. Nov. 198410. Juni 1986Kimball International, Inc.Hydraulic chair lift mechanism
US4621868 *6. Sept. 198511. Nov. 1986Kimball International, Inc.Height control mechanism
US5234187 *2. Juni 199210. Aug. 1993Steelcase Inc.Chair height adjustment mechanism
US5366275 *16. Juni 199322. Nov. 1994L & P Property Management CompanyGas operated foot stool
US5511759 *26. Mai 199430. Apr. 1996Steelcase, Inc.Hydraulic chair height adjustment mechanism
US5992940 *29. Juli 199830. Nov. 1999Jing-Dean Enterprises Co., Ltd.Support tube for an office chair
US6499705 *4. Jan. 200231. Dez. 2002Ming-Liang TsaiMulti-purpose supporting structure
US739296514. März 20051. Juli 2008Lg Electronics Inc.Monitor stand
US739599225. Jan. 20078. Juli 2008Lg Electronics Inc.Monitor stand
US8308124 *28. Okt. 201013. Nov. 2012Jung Yu HsuControl device for adjustable bicycle seat
US20050087957 *23. Okt. 200328. Apr. 2005Bennett John E.Riser seat and wheelchairs with same
US20050199773 *14. März 200515. Sept. 2005Lg Electronics Inc.Monitor stand
US20070158510 *25. Jan. 200712. Juli 2007Jung Gil SMonitor stand
US20070266913 *17. Mai 200622. Nov. 2007Balt, Inc.Workstation
US20120104809 *28. Okt. 20103. Mai 2012Jung Yu HsuControl device for adjustable bicycle seat
EP1577600A3 *15. März 200523. Nov. 2005LG Electronics Inc.Monitor stand
EP1821028A1 *15. März 200522. Aug. 2007LG Electronics Inc.Monitor stand
WO1989008417A1 *7. März 198821. Sept. 1989Bengt PeterssonAn arrangement for stepless vertical adjustment of a chair seat
US-Klassifikation248/404, 297/344.19, 92/152, 297/339, 108/147, 60/414, 92/143, 91/5
Internationale KlassifikationA47C3/30, A47C3/20
Europäische KlassifikationA47C3/30