WO1991013314A1 - Mecanisme pour le reglage en hauteur des chaises - Google Patents

Mecanisme pour le reglage en hauteur des chaises Download PDF

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Publication number
WO1991013314A1
WO1991013314A1 PCT/US1990/000997 US9000997W WO9113314A1 WO 1991013314 A1 WO1991013314 A1 WO 1991013314A1 US 9000997 W US9000997 W US 9000997W WO 9113314 A1 WO9113314 A1 WO 9113314A1
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WO
WIPO (PCT)
Prior art keywords
spindle
nut
spring
seat
housing
Prior art date
Application number
PCT/US1990/000997
Other languages
English (en)
Inventor
James Jann
Original Assignee
James Jann
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by James Jann filed Critical James Jann
Priority to PCT/US1990/000997 priority Critical patent/WO1991013314A1/fr
Publication of WO1991013314A1 publication Critical patent/WO1991013314A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
    • A47C3/20—Chairs or stools with vertically-adjustable seats
    • A47C3/24—Chairs or stools with vertically-adjustable seats with vertical spindle
    • A47C3/245—Chairs or stools with vertically-adjustable seats with vertical spindle resiliently supported
    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47C—CHAIRS; SOFAS; BEDS
    • A47C3/00—Chairs characterised by structural features; Chairs or stools with rotatable or vertically-adjustable seats
    • A47C3/18—Chairs or stools with rotatable seat

Definitions

  • One of the common arrangements for adjusting the height of the seat of a chair is to mount the seat on a threaded spindle that engages a nut that is rotatably fixed with respect to the base of the chair when no weight is present on the seat. Rotation of the seat in either direction then raises or lowers it according to the direction of rotation. Placement of weight on the seat disengages a clutch mechanism that leaves the nut free to turn with the spindle as the occupant of the seat turns to face in different directions.
  • the present invention provides a simplified structure with regard to the cost of component parts and the assembly procedures, while retaining a combination of the desirable features ' .isted above.
  • the present invention also provides a cushioned spring support for the occupant in combination with a long spring envelope that reduces stress on the spring.
  • a tubular housing fixed to the base of the chair has an upper section of expanded diameter providing a chamber containing the clutch mechanism.
  • a shoulder at the bottom of the chamber functions as a support for the lower spindle bearing in one form of the invention. in a modified form of the invention, the material forming the shoulder itself becomes the bearing.
  • the upper bearing for the spindle closes the top of the housing, and positions the spindle laterally while allowing it to move freely axially.
  • the adjustment nut is directly below the upper bearing, and is biased upwardly against the lower transverse face of this bearing to form a clutch. Downward movement of the spindle in response to the presence of weight on the seat compresses the biasing spring, and releases the nut to turn with the spindle. Spring washers keyed to the spindle bear against the lower spindle bearing and against the underside of the nut for axial thrust transfer.
  • the spring thus provides a resilient cushioned support for the chair occupant. Because of the configuration of the height adjustment mechanism, the spring has a long spring envelope that reduces stress on the spring while providing a cushioned support for occupants over a wide range of weights.
  • the present invention also includes a lower bearing that includes an elongated lower member and a number of bearing extension members that make it possible to use a single size of lower bearing for height adjustment mechanisms of different lengths.
  • FIG. 1 is an axial section of the adjustment mechanism in a condition corresponding to the absence of weight on the seat of the chair.
  • FIG. 2 is a section similar to FIG. 1, but in a condition corresponding to the presence of weight on the seat.
  • FIG. 3 is a side elevation of the upper bearing.
  • FIG. 4 is a bottom view with respect to FIG. 3.
  • FIG. 5 is a top view of the adjustment nut.
  • FIG. 6 is a side elevation with respect to FIG. 5.
  • FIG. 7 is a top view of one of the keyed spring washers.
  • FIG. 8 is a side elevation with respect to FIG. 7.
  • FIG. 9 is a sectional view through the threaded portion of the spindle.
  • FIG. 10 is a top view of the lower bearing.
  • FIG. 11 is a side elevation with respect to FIG. 10.
  • FIG. 12 is an axial section showing a second embodiment of the invention.
  • FIG. 13 is a top view with respect to FIG. 12.
  • FIG. 14 is a side elevation of one of the spring thrust washers.
  • FIG. 15 is a bottom view with respect to FIG. 14.
  • FIG. 16 is a partial side elevation showing a modified form of the first embodiment.
  • FIG. 17 is a partial side elevation of the second embodiment employing a 45 millimeter taper.
  • FIG. 18 is a side elevation of the second embodiment employing a 40 millimeter taper.
  • FIG. 19 is a partial side elevation of the second embodiment employing a 50 millimeter taper.
  • FIG. 20 is a top view of the adjust nut of the second embodiment.
  • FIG. 21 is an inverted cross sectional view of a modified upper bearing of the second embodiment.
  • FIG. 22 is an axial cross-section of another embodiment of the adjustment mechanism of the present invention in a condition corresponding to the absence of weight on the chair.
  • FIG. 23 is an axial cross-section of the embodiment of FIG. 22 in a condition corresponding to the presence of weight on the chair.
  • FIG. 24 is a side elevational view of a lower bearing extension member employed in embodiment of FIG. 22.
  • FIG. 25 is a bottom plan view of the bearing of FIG. 24.
  • FIG. 26 is a side elevational view of the lower bearing member of the FIG. 22 embodiment.
  • FIG. 27 is a lower plan view of the lower bearing member of FIG. 26.
  • the tubular steel housing 20 is fixed with respect to the base 21.
  • This base is conventional, and represents the central area at the intersection of a group of radially-extending legs provided with casters .
  • the lower extremity of the housing indicated at 22 is provided with a slight swaged taper of one (1) degree, eight (8) minutes, and forty-six (46) seconds per side to provide a solid forced-fit engagement of the mechanism to various standard chair bases.
  • the tubular steel column in FIGS. 1 and 2 is constructed as what is known in the industry as a forty (40) millimeter taper. The measurement refers to the outside diameter of the tubular steel column which is compatible with the dimensional requirements for many of the office chair bases manufactured in the United States . As will be discussed further, there are other size conventions within the industry, none of which represent a limitation of the present invention.
  • the central portion of the housing 20 has a tapered expansion of diameter indicated at 23 providing a wedging shoulder for supporting the lower spindle bearing 24.
  • the upper portion of the spindle 25 is supported by the bearing 26 forced into the slightly flared upper extremity of the housing 20.
  • the lower bearing 24 has its outer surface 27 tapered to conform to the shoulder 23 of the housing.
  • the central opening 28 receives the spindle 25 with freedom for rotation and axial movement.
  • the top bearing 26 has a tapered side shown at 29 to conform to the flared expansion of the upper extremity of the housing 20.
  • the flange 30 is provided both for appearance, and to limit the forced penetration of the top bearing into the housing.
  • the hole 31 also receives the spindle 25 with freedom of rotation and axial movement.
  • the upper portion of the spindle 25 is threaded as indicated at 32.
  • the spindle is a solid steel rod one (1) inch in diameter, with seven (7) threads per inch.
  • the preferred thread is an American Standard Stub Acme thread.
  • the conventions of the chair industry have emphasized the usage of the seven (7) threads per inch standard, although modifications of this are certainly consistent with the use of the present invention.
  • Alternatives to the preferred threads include the use of a six (6) threads per inch design as well as an eight (8) threads per inch design.
  • the eight (8) threads per inch version will understandably have different adjustment characteristics since more turns are necessary to advance or retract a spindle. The opposite is true for the six (6) threads per inch design which will advance and retract with correspondingly less rotation of the spindle.
  • the chair industry as mentioned above, has favored the seven (7) threads per inch specification.
  • the length of the threaded portion determines the range of adjustment of the mechanism.
  • the upper extremity of the spindle is provided with a self-locking taper 33 for engagement with a standard socket provided at the underside of the seat (not shown) of the chair.
  • the snap ring 34 engages an appropriate groove in the spindle to limit the downward movement of the spindle with respect to the bearing 26.
  • the nut 35 is in threaded engagement with the spindle. This nut, and the spindle with it, are biased upwardly by the coiled compression spring 37 acting between the keyway thrust washers 38 and 39. These can both be alike, and are shown in FIGS. 7 and 8.
  • FIG. 1 shows the condition of the components without substantial weight on the seat of the chair.
  • the assembly of this device is the ultimate in manufacturing simplicity.
  • a sub-assembly of the spindle 25, lower bearing 24, spring washer 39, spring 37, upper spring washer 38, nut 35, and upper bearing 26 can be inserted axially into the upper end of the tubular housing 20, with the lower bearing taking a firm seat in the column as a result of its approximate seven and one-half (7-1/2) degree taper matching with the portion 23 of the column.
  • the nut 35 of course, has previously been threaded down to the point where the top bearing 26 can assume its assembled position. With the components thus in place, the tubular housing is staked as shown at 46 to secure the assembly in place.
  • the indentations of the staking operation can either be driven into the metal of the top bearing, or a shallow groove can be provided in the periphery of the top bearing opposite the position of the staking. In either case, the result is an interlock which secures the assembled relationship.
  • Other means can be empxoyed to achieve the same function including set screws, roll pinning and other methods known in the art.
  • the spring force applied to nut 35 can be selectively adjusted to achieve benefits in the present embodiment that have not been possible in similar mechanisms. Since the present invention allows for a larger spring "envelope" where the envelope is defined by the vertical distance between the thrust washers 38 and 39, the load applied to the spring is then spread or distributed over a spring with a greater number of coils, thereby reducing the torsional stress level of the spring. This advantage is best illustrated in those circumstances where the loading on springs and similar devices is higher than the anticipated average design loading. Under this kind of usage the spring will tend to develop a "set" which diminishes its operating characteristics.
  • the life of the spring can be predictably increased as well as allowing a more precise accommodation of load characteristics for particular applications.
  • the force characteristics of a spring are represented by the spring rate or spring constant of the spring, which indicates the force exerted by the spring in relation to the amount of deflection (compression in this case) of the spring.
  • a spring constant may be expressed in units such as pounds of force per inch of compression.
  • the maximum force or compressive resistance exerted by a compression spring is represented by the spring constant times the amount of spring travel between its uncompressed state and its fully compressed state (i.e., when the coils are bottomed out or touching) .
  • the maximum compressive resistance of the spring represents the maximum weight that the spring can support before it bottoms out.
  • the spring length and constant and preloading are carefully selected to prevent the seat from bottoming out for most anticipated users (thus providing a comfortable cushioned feel for the seat user) while still providing a clutch that reliably deactuates when the seat is occupied and not before.
  • the spring is formed of eight and one half (8-1/2) coils of 0.177 inch diameter spring wire, and the spring is preloaded for generating approximately eighty (80) pounds of support prior to compression (i.e., before the spindle is depressed downwardly) .
  • the terminal ends of the spring coil are staggered by one hundred eighty (180) degrees in order to balance the spring action.
  • a spring formed of 0.218 inch diameter wire with six and one half (6-1/2) coils is used to achieve a higher degree of support before the spring bottoms out.
  • the foregoing springs while operable, permit the spring to bottom out too easily for many users.
  • a preferred embodiment of the spring of the present invention employs five and one-half (5 1/2) coils of wire 0.234 inches in diameter. This spring is preloaded to 110 pounds. Assuming a seat weight of thirty (30) pounds (most seats, including mounting mechanisms, weigh twenty (20) to thirty (30) pounds), an eighty pound person can release the clutch and a two hundred sixty pound person will not bottom out the spring. The spring takes about 296 pounds to bottom out or fully compress. Other springs can accomplish a similar effect.
  • the spring wire could be as thin as 0.150 inches (more desirably three sixteenths [0-0185] inches) or as thick as five sixteenths (0.3125) inches in diameter. A preferred range is 0.21 to 0.25 inches in diameter.
  • Flat wire springs of comparable cross sectional area also could be employed. This would give the spring greater travel between the compressed and uncompressed conditions of the spring. Even a series of Bellville washers or wave springs could be feasible.
  • the important spring characteristics are that a person of a projected minimum weight (generally no more than about 90 pounds and preferably 80 pounds or less), should be able to release the clutch, and a person of the maximum projected weight (preferably a person weighing at least 220 or 240 pounds and ideally a person weighing 270 pounds or more) should be able to sit on the chair and feel the cushioning effect of the spring without fully compressing or bottoming the spring out.
  • Spring weight determinations in any such application include the weight of the chair seat itself.
  • the spring should at least be preloaded to forty (40) pounds to keep the unoccupied seat from releasing the clutch.
  • the preload on the spring probably should not exceed about one hundred twenty (120) pounds.
  • a preload of about one hundred ten (110) pounds is preferred.
  • the maximum compressive force of the spring for normal applications should be at least two hundred twenty (220) pounds.
  • a maximum compressive force of at least two hundred fifty (250) pounds is preferable and a maximum compressive force of at least two hundred seventy (270) pounds is even more preferred.
  • the maximum compressive force of the spring is about two hundred ninety six (296) pounds.
  • Spring wire thickness, spring length, and preload all affect the foregoing features in the present invention.
  • the longer spring envelope achieved with the bearing and spring position of the present invention is especially important in making it possible to provide a spring support that releases the clutch with a light person, permits a spring cushion ride for even heavy persons and provides reduced stress on the spring during loading.
  • the firmness or feel of the seat may be affected.
  • the spring tension and the amount of play between the engaged and disengaged positions will cooperate to cushion the actual act of sitting. This creates an illusion of a more cushioned chair which is a perceived advantage to the office chair purchaser as well as the user.
  • the number of coils is one of the most important features in increasing the longevity of the spring and th * - weight range of spring performance. With a greater number of coils are available for use in the spring envelope of the present invention, the compression required of each coil to produce a given deflection is reduced. To provide adequate durability and a desirable range of operation, the spring should have at least 4 1/2 coils and preferably at least five (5) coils. The coil employed in the preferred practice of present invention employs five and one-half (5 1/2) coils. The amount of spring compression permitted by the height adjustment mechanism also is a significant feature of the spring mechanism of the present invention. Spring compression is the change in length of the spring between the initial or preloaded state and the loaded state when the ⁇ hair is occupied.
  • This distance should be at least 0.050 inches for the lightest anticipated user, in order to insure that the clutch is released. A compression of that amount also would provide a noticeable but modest cushioning effect. A preferred cushioning effect is provided if the spring compression is at least one- quarter (1/4) of an inch. Maximum spring travel or compressibility under maximum anticipated loads desirably should be less than one (1) inch, in order to prevent the seat from sinking too far downwardly when a person sits on it. Excessive spring compression makes the chair height difficult to adjust and is otherwise undesirable. A maximum spring compression of one-half (1/2) inch is a preferred maximum. The preferred spring of 5 1/2 coils of 0.234 inch wire has a maximum spring compressibility or travel of 0.320) inches.
  • the spring envelope, or length of the preferred spring in its preloaded condition is about 1.620 inches.
  • a spring envelope of at least about one and one-half (1 1/2) inches is preferred.
  • the spring support me ⁇ h nism of the present invention provides a chair height adjustment mechanism that allows even a very light occupant to compress the spring beyond the engagement point while seated, freeinq the chair from the adjustment mode. At the same time, even a heavy occupant experiences a cushioned ride on the spring with little or r ⁇ > adverse effect upon the spring.
  • the expansion bias causes the spring to return to its initial preload state, thereby engaging the clutch and the nut and allowing the chair height to be adjusted when the chair is rotated.
  • the tubular steel column of the present embodiment accomplishes several objectives.
  • the lower portion of the column 22 has an industry defined taper for insertion into chair base constructions. This taper is most often a forty (40) millimeter diameter with a 1°8'46" angular decline in the direction of the bottom of the tubular steel column. The taper thus interlocks with the chair base providing a snug fitting combination that insures chair stability.
  • FIGS. 17 and 19 additional tapers based on a forty-five (45) millimeter tubular column and a fifty (50) millimeter tubular column respectively, are shown in phantom.
  • the forty-five (45) millimeter taper has an angular decline of 2°35' while the fifty (50) millimeter taper has an angular decline of l ⁇ 26'16".
  • the wedging shoulder 23 of the present embodiment is provided by incorporating a taper at this particular point in the steel column itself.
  • the taper is preferentially a seven and one-half (7-1/2) degree angle, however tapers may range from as little as approximately three (3) degrees to as great as approximately fifteen (15) degrees. It is noted that the smaller angles or tapers require a greater precision in order to avoid misplacement of the bearing. Slight differences in the outer diameter of the bearing will have a greater effect when the taper is small than when the taper is large.
  • the preferential composition of the bearings is nylon or even more preferrably Delrin D-500.
  • the experience in using such bearings in a six (6) degree taper indicates that they are resistant to substantial creep. Nonetheless, alternative means may be employed to stake or otherwise secure the bearing in place.
  • FIG. 16 a portion of a chair height adjustment mechanism is shown in cross section.
  • the chair base 70 is shown receiving the tubular steel column 72.
  • a lower taper 78 is employed to assist in the seating of the steel column in the chair base.
  • other features such as the wedging shoulder 74, the keyway washer 80 and the spindle 82 are in the same relation and are of the same construction as the previously discussed embodiment.
  • the lower bearing 84 is extended to the end of the tubular steel column where it meets up with an end flange 56 resulting from the turning in of the taper of the steel column.
  • the components of the lower bearing consist of the upper portion 86, the lower bearing extension 88 and the lower bearing end 90.
  • the modification in FIG. 16 holds the lower bearing in precise orientation with the rest of the components of the chair height adjustment mechanism. Any tendency for the lower bearing to creep is eliminated in this embodiment. In this fashion, the lower bearing may be said to be captured within the steel column of the modification.
  • the stability of the lower bearing is sufficient for operation of the chair height adjustment mechanism.
  • the methodology for freezing the lower bearing in the column is typically with set screws, staking by deformation, by roll pinning or by other various means. These all require additional steps or special machining in order to obtain the desired contour to the outer diameter of the taper in the tubular column. With the features of the present invention, these requirements are eliminated as well as reducing the steps necessary for assembly.
  • the tubular steel column in the present embodiment is preferably .060 inches wall thickness. It has been found that this thickness is compatible with the drawing and forming operations necessary to develop the previously described tapers.
  • the wall thickness may be greater than the .060 inches up to approximately .105 inches.
  • Other versions of chair height adjustment mechanisms have relied upon wall thicknesses as great as .125 inches where the lower taper has been subsequently machined to a wall thickness approximating the .105 inch thickness or less in order to insure the proper contour for installation in the chair base.
  • the advantage of the present invention therefore, allows the usage of thinner and lower cost stock materials that are more easily worked into the required product.
  • the usage of the .105 inch stock raises the possibility of using the tubular column support as the hub for the installation of legs for the chair base. It is possible in this circumstance for the legs to be welded directly to the column support of the present invention thereby foregoing the expense of a cast or separately fabricated base component and eliminating the necessity for a tapered column support.
  • the usage of dual bearings in chair height adjustment mechanisms is a feature that has evolved over time.
  • the bearings which have detracted from their maximum benefit.
  • the bearings should be placed as far apart vertically as possible. This, plus the additional feature of placing the upper bearing as close to the chair bottom as possible increases the stability and durability of the chair height adjustment mechanism.
  • Related limitations evidenced in other devices have come about as a result of the orientation of the components which have also restricted the amount of stroke that the spindle may realize in a given situation.
  • the stroke for a chair height adjustment mechanism should have a minimum of four (4) inches of travel. In the present invention, four and one half (4-1/2) inches is possible. Other devices have compensated for the lack of stroke by allowing additional travel through "stick out". Stick out refers to the amount of spindle that is advanced below the chair base in the lowest chair setting. Stick out is objectionable for the reason it is unsightly and may permit grease or oil to contact carpeting or clothing in the office environment.
  • this embodiment of the invention has an integral molded housing 47 that has an upper portion defining a chamber 48 containing a clutch mechanism similar to that illustrated in FIGS. 1 and 2.
  • the remaining components, with the exception of the spring 49 and the spindle 52 can also be molded from plastic or composite materials.
  • the top bearing 50 is pressed, adhesively secured, thermally welded or otherwise secured to the upper end of the housing 47, and rotatably interlocks with the nut 51 through the interengagement of projections and recesses as previously described, depending upon the axial position of the spindle 52 with respect to the housing 47.
  • the housing has a lower portion 53 providing a lower bearing of the system, and the reduction in diameter from that of the chamber 48 to the inside diameter of the lower portion 53 provides the shoulder 54 acting as the thrust bearing transferring the spring forces from the thrust washer 55.
  • the upper thrust washer 56 can be identical, and these are illustrated in FIGS. 14 and 15.
  • the central axial extension 57 locates the spring 49 radially, and the central axial opening 58 has the flat sides 59 and 60 providing non-rotative engagement with the spindle 52. With this arrangement, the spring and the two thrust washers rotate with the spindle at all times, with relative rotation taking place between the lower thrust washer 55 and the shoulder 54.
  • the lower portion 53 of the housing has a slightly tapered exterior for interengagement with the standard configuration of a chair base, and the periphery of the composite spindle 52 is tapered at its upper extremity for interengagement with the seat structure of the chair.
  • the snap ring 61 is provided to limit the downward movement of the spindle with respect to the housing, as in the FIG. 2 assembly.
  • the spindle threads 62 conform with the desired industry specification. Functionally, the arrangements shown in FIG. 12 and those of FIGS. 1 and 2 are the same.
  • the second embodiment takes advantages of the properties of plastic in the construction of a chair height adjustment mechanism.
  • the advantages include the ability to mold many of the features directly into the housing 47.
  • the reduction in labor and materials is tremendous and greatly reduces the manufactured cost of the product without altering the function.
  • the thrust washer 56 when constructed out of plastic materials is more beneficial than steel in either embodiment.
  • the steel washers have the potential for cross threading onto the spindles especially where the metal thickness is one-eighth (1/8) inch or less. The chance that the washer in such a case would match up with the corresponding thread with the spindle is increased and damage occurs to both the spindle and the washer in such a situation.
  • the housing 47' is a plastic construction. In accordance with the present embodiment, it is essentially a replicate of the component as shown in FIG. 12 previously.
  • the other components, 48' through 62' are similarly the equivalent of the previously discussed features.
  • the upper bearing 100 and adjust nut 112 have special detent features which are different from the corresponding parts in FIG. 12.
  • a detent 106 is found on the upper surface and adjust nut web spaces 104 occur in between the adjust nut webs 112.
  • the nut includes thread 105 which corresponds to the threads 62 x of the spindle.
  • the adjust nut being constructed of plastic, is preferably made to incorporate a series of radial webs in the injection molded part.
  • the preferred number of webs is eight (8), leaving eight (8) web spaces as well.
  • the detents as viewed in FIG. 20 are radially oriented and correspond to the web spaces in the upper bearing.
  • the upper bearing as illustrated in FIG. 21, possesses web spaces 108 and webs 110 as part of its overall plastic construction.
  • the upper bearing however, has no detents so it differs slightly from the adjust nut in that respect.
  • the webs and web spaces of the upper bearing are functional in the practice of the present invention.
  • the bearing web spaces 108 occur in substantial alignment with the detents 106 of the adjust nut. In this way, a clutch interface is formed of a more positive nature between the adjust nut and the upper bearing.
  • the positive engagement of eight (8) detents within the corresponding web spaces of the upper bearing affirmatively causes the adjust nut to be held during the chair height adjustment process.
  • the clearance necessary to disengage the adjust nut from the upper bearing must be at least equal to the height of the detent.
  • the affirmative engagement between the adjust nut and the upper bearing requires less spring tension to affect the clutching action and torsional force between the detents and the bearing webs is used to affect the actual adjustment.
  • the spacing of the detents and the webbing is no accident. Aside from the structure integrity the webbing gives to the individual bearing or adjust nut, the spacing in eight (8) segments provides for an immediate initiation of the adjustment. No more than one-eighth (1/8) turn is required before actual engagement is made when the load is removed from the chair height adjustment mechanism. This reduces any perceptible slackness in the adjustment mechanism.
  • chair height adjustment mechanism 150 comprises a tubular steel housing 152, with an upper bearing 154 mounted in the upper end of the housing and a lower bearing 156 mounted in the lower end of the housing.
  • a spindle 158 is carried between the bearings.
  • the lowermost end of the housing is tapered inwardly and lower bearing 156 is tapered to fit the housing.
  • lower bearing 156 engages the spindle to the bottom of the housing.
  • a nut 160 is positioned below upper bearing 154, and the nut is urged upwardly by a preloaded spring 162, which is sandwiched between upper and lower washers 164 and 166.
  • Lower bearing 154 comprises a tapered lower member 168 that fits in the lower end of the housing 152.
  • the bearing has a tubular portion 170 that surround the spindle and radially spaced ribs 172 that extend outwardly to the housing to center the bearing and hold the spindle in place.
  • a radial flange 174 extends outwardly from the top of the bearing to the housing.
  • each bearing extension member 176 has a tubular center portion 178 with radially spaced ribs _180 and an upper flange 182, just like the lower bearing except that the ribs of the lower bearing are tapered to fit in the housing.
  • FIGS 22-27 Another difference in the mechanism of FIGS 22-27 is the upper bearing is fastened in the housing by pins 184.
  • the FIGS 22-27 embodiment is substantially the same as the embodiment of FIG. 1.
  • the spindle has a tapered upper end 186 that fits in a seat mounting mechanism, with a snap ring 188 mounted in spindle groove 190 limiting the downward adjustment of the spindle into the housing, as in the previous embodiments.
  • a tapered lower end of the hoiking fits in a seat base.
  • the clutch is held in an engaged position by the preload on the spring when the chair is unoccupied.
  • the spring is partially but not completely compressed, providing a resilient spring cushion for the chair user.

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  • Chairs Characterized By Structure (AREA)

Abstract

Ce mécanisme pour le réglage en hauteur des chaises a un logement tubulaire (152) fixé à la base de la chaise, avec des coussinets échelonnés verticalement (154) fournissant un soutien latéral à une broche filetée (158) assujettie au siège de la chaise. Le coussinet supérieur (154) permet à la broche (158) de bouger de manière axiale, et un écrou (160) qui s'engage dans les filets de la broche (158) sous le coussinet supérieur (154) est sollicité vers le haut pour venir en prise avec l'extrémité inférieure de ce coussinet (154). Le ressort utilisé à cet effet (162) agit entre les rondelles (164, 166) calées contre la broche, la rondelle inférieure étant soutenue par la face supérieure du coussinet inférieur(174). Un poids sur le siège pousse la broche vers le bas à l'encontre du mouvement du ressort, dégageant ainsi l'écrou (160) de manière qu'il puisse tourner avec la broche (158), éliminant de la sorte toute variation du réglage en hauteur de la chaise lorsque celle-ci est occupée. Le ressort (162) supporte de manière élastique le poids de l'occupant de la chaise, lui offrant une sensation d'amortissement. Le coussinet inférieur peut comprendre un élément inférieur standard (174), ainsi qu'une série d'éléments de rallonge de coussinets pour fournir un support rallongé permettant d'obtenir un mécanisme de réglage en hauteur à course plus longue (176) utilisant des éléments de taille standard.
PCT/US1990/000997 1990-02-22 1990-02-22 Mecanisme pour le reglage en hauteur des chaises WO1991013314A1 (fr)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8152258B2 (en) 2006-11-20 2012-04-10 Lg Electronics Inc. Elevation adjustment apparatus for shelf in refrigerator
US8210626B2 (en) * 2006-11-20 2012-07-03 Lg Electronics Inc. Elevation adjustment apparatus for shelf in refrigerator
US8226184B2 (en) 2006-11-20 2012-07-24 Lg Electronics Inc. Height adjusting apparatus of shelf for refrigerator

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DK69161C (da) * 1946-07-08 1949-05-09 Harald Carl Emil Van Deurs Taburet, stol eller lignende siddemøbel.
US3455601A (en) * 1966-11-02 1969-07-15 Finn Lie Support unit for chair
US3870271A (en) * 1973-10-31 1975-03-11 Harter Corp Fully enclosed, adjustable, support column for a pivotal chair
US3991965A (en) * 1976-01-27 1976-11-16 Gf Business Equipment, Inc. Chair height adjusting mechanism
GB2060361A (en) * 1979-10-06 1981-05-07 French J A W Adjustable support devices for swivel chairs
GB2065462A (en) * 1979-11-01 1981-07-01 Bliss & Laughlin Ind Vertically adjustable swivel chair
US4394001A (en) * 1981-03-18 1983-07-19 Haworth, Inc. Height-adjusting mechanism for chair seat
US4440372A (en) * 1981-03-18 1984-04-03 Haworth, Inc. Bellows mounting arrangement for swivel chair
US4540148A (en) * 1983-11-10 1985-09-10 Jann James M Chair height adjustment mechanism
US4562982A (en) * 1984-02-15 1986-01-07 Panduit Corp. Stackable cable spacer
US4598892A (en) * 1984-07-27 1986-07-08 Haworth, Inc. Mechanical chair-height control mechanism

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8152258B2 (en) 2006-11-20 2012-04-10 Lg Electronics Inc. Elevation adjustment apparatus for shelf in refrigerator
US8210626B2 (en) * 2006-11-20 2012-07-03 Lg Electronics Inc. Elevation adjustment apparatus for shelf in refrigerator
US8226184B2 (en) 2006-11-20 2012-07-24 Lg Electronics Inc. Height adjusting apparatus of shelf for refrigerator

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