Laterally Adjustable Armrest for a Chair

The present invention relates to furniture and more particularly to a chair having unique, laterally adjustable armrest assemblies.

A wide variety of task chairs adapted for the office environment are presently available. Such chairs include various adjustments to adapt them to the particular user and task. The chairs may, for example, include vertically adjustable seat height mechanisms, swivel/tilt mechanisms and adjustable back height mechanisms. Office chairs may be provided with arm assemblies. Heretofore, such chairs have had a fixed width between the armrests. The chairs have not been readily adaptable to different users.

A need exists for an armrest assembly for a chair which permits lateral adjustment of the width between the armrests.

In accordance with the present invention, the aforementioned need is met. Essentially, a laterally adjustable armrest assembly is provided which includes an armrest support and an armrest Adjustment means between the support and the armrest permit selective, lateral adjustment or transverse adjustment of the armrest with respect to the support. As a result, the user may position the armrests at differing widths to more readily accommodate the individual and adapt the chair to a particular task.

FIG. 1 is a front, elevational view of a chair in accordance with the present invention;

FIGS. 2 and 2a are transverse cross sectional views showing the armrest in two different lateral positions;

FIG. 3 is a cross sectional view taken generally along line III--III of FIG. 2;

FIG. 4 is a perspective view of a bracket incorporated in the present invention;

FIG. 5 is a cross sectional view taken generally along line V--V of FIG. 4;

FIG. 6 is a right end elevational view of the bracket of FIG. 4;

FIG. 7 is a top, plan view of the bracket;

FIG. 8 is bottom view of an armrest member incorporated in the present invention;

FIG. 9 is a right side, elevational view of the armrest member of FIG. 8;

FIG. 10 is a cross sectional view taken generally along line X--X of FIG. 8;

FIG. 11 is a cross sectional view taken generally along line XI--XI of FIG. 8; and

FIG. 12 is a cross sectional view taken generally long line XII--XII of FIG. 8.

A chair including laterally adjustable armrest assemblies in accordance with the present invention is illustrated in FIG. 1 and generally designated by the numeral 10. Chair 10 includes a support pedestal 12 mounted on a castered base 14. A seat 16 is mounted on pedestal 12 by a suitable chair control (not shown). A chair back 18 is also mounted on pedestal 12 by the chair control and by suitable supports 20. In a conventional fashion, a mechanism may be included for adjusting the vertical height of seat 16 with respect to base 14. In addition, a chair back adjustment mechanism may also be included for positioning the seat back 18 with respect to the seat 16.

Chair 10 further includes a generally U-shaped, tubular armrest support 22 defining generally vertically extending support portions or members 24. Members 24 extend vertically adjacent lateral sides of seat 16.

Mounted on upper ends 26 of support members 24 are armrest assemblies 30 in accordance with the present invention. As shown in FIGS. 2 and 3, each armrest assembly 30 includes a mounting bracket 32, a lower armrest member 34 and an upper armrest member 36. Upper armrest member 36 may be a soft or upholstered unit or a rigid plastic unit which is joined to lower member 34. In the alternative, members 34, 36 could be integrally formed.

As seen in FIGS. 4-7, bracket 32 is a generally elongated member having a U-shaped cross section. Bracket 32 includes a base 40, an angled end 42 and upwardly extending elongated sides or walls 44. Walls 44 are joined at the end opposite portion 42 by an upwardly and acutely angled tongue 46. Tongue 46 defines a generally semi-circular tab or ear portion 48 having an aperture 50. As shown in FIGS. 2 and 3, bracket 32 is secured in a suitable fashion to upper end 26 of support member 24, such as by a weld 52.

Lower armrest member 34 is best shown in FIGS. 8-12. Member 34 has an elongated configuration and defines an undersurface 62. Member 34 includes a central portion 64 and ends 66, 68. Central portion 64 defines or includes a plurality of longitudinally extending, spaced parallel ribs 70 and side walls 72. The ribs 70 and side walls 72 as seen in FIGS. 2 and 12 define grooves 74. Grooves 74 open downwardly through the lower surface of member 34.

A downwardly angled surface 80 extends transversely of ribs 70 towards end 66. Surface 80 is formed with a plurality of apertures 82. As seen in FIG. 8, apertures 82 are formed along the longitudinal center lines of grooves 74. Forward portion 68 of the armrest defines a ramp 89 (FIG. 3). Ramp 89 cooperates with bracket 32 as described below. In addition, the undersurface of member 34 may define attachment apertures 86. Apertures 86 serve as attachment points for upper armrest member 36. As seen in FIG. 3, armrest member 34 is secured to bracket 32 by a suitable fastener 90 extending through aperture 50 in bracket 32 and into one of the apertures 82.

In order to adjust armrest member 34 transversely or laterally with respect to bracket 32 and armrest support 24, fastener 90 is initially removed. Member 34 may then be lifted off of the bracket and moved laterally until side walls 44 are positioned in a selected pair of the grooves 74. Movement of the armrest from a centered position to a outward position is illustrated in FIGS. 2 and 2a. When positioned in the desired location, fastener 90 is reinserted. The fastener 90 will draw the complementary angled surfaces of tongue 46 and surface 80 of member 34 towards each other into a mating relationship. The fastener, therefore, also wedges ramp 89 into angled end 42 of bracket 32 thereby locking the front of armrest 3 in position. The fastener 90 tightens the armrest member 34 to the bracket 32 and hence to support 24. The elongated nature of the bracket 32 and the elongated nature of the grooves 74 securely retain the armrest member 34 and prevent rotational movement or shifting about a vertical axis. In the form illustrated, five grooves are defined. The armrest may, therefore, be positioned selectively in one of three different lateral positions with respect to the support 24. The U-shaped bracket in cross section provides adequate support to eliminate any rolling action of the armrest member about a horizontal or longitudinal axis. The armrest is retained in a positive fashion at the selected positions.

As should be readily apparent, the user may easily position the armrest assemblies 30 to increase or decrease the width between the rests with respect to the seat 16 and the supports 24 from a centered position. Chair 10 has, therefore, increased adjustability not heretofore obtained. The assembly is relatively easily manufactured employing conventional procedures. The lower armrest member 34 may be fabricated from a rigid engineering plastic material, such as a glass reinforced nylon. It is presently preferred, however, that the material be a polyphenylene oxide. Such material is commercially available under the brand name PPO or under the brandname Noryl which is sold by General Electric. Bracket 32 is preferably manufactured from steel. The armrest may, therefore, be readily molded in different configurations to suit the design considerations or appearance of the chair while readily forming the ribs and grooves which form a portion of the adjustment mechanism. The bracket may be easily stamped from steel sheet.

In view of the above description, those of ordinary skill in the art may envision various modifications which would not depart from the inventive concepts disclosed. For example, the armrest support need not be a U-shaped tubular member. Individual support members could be secured to the chair base or to the chair seat. In addition, the bracket 32 could be joined integrally to or formed as an integral part with the armrest support member. It is expressly intended, therefore, the above description should be considered as only that of the preferred embodiment The true spirit and scope of the present invention may be determined by reference to the appended claims.