Pivoting armrest

[0001] The present invention relates to a pivoting armrest assembly that can be pivoted between an in use horizontal position and an out of the way vertical position.

[0002] Pivoting armrests that allow the arm to be rotated between a horizontal and vertical position for various types of seats are known in the art. In fact, there are a variety of different constructions to achieve the pivoting feature. However, depending on the particular design, the function of a pivoting armrest can result in a number of potential problems for a user.

[0003] When a user moves the armrest from a vertical position to a horizontal position, the interaction between the upper arm and the support structure can result in a pinch point where an object can be caught between the arm and the support structure. This is particularly evident with pivoting armrest designs that have a protruding support element adapted to tuck into a cavity in the arm when in the horizontal position. This type of design can create a potential pinch area either by exposing the cavity during movement of the armrest and enabling an object to be caught within the cavity, or by exposing the support structure and allowing objects to be caught thereon when the arm is not in the horizontal position. It is desirable to have a pivoting armrest that does not create the potential pinch areas described above.

[0004] Still another concern with a pivoting armrest relates to the robustness of the design. In order to create the pivoting motion, certain clearances must be designed into the pivot joint to allow the arm to pivot freely. In doing this, the pivot connection may develop looseness or slop and may result in a rattle noise within the connection. It would be desirable to have a pivoting armrest design that eliminates this type of loose condition.

[0005] Accordingly, the inventors have recognized the aforementioned problems and have designed an apparatus having the aforementioned desired advantages.

[0006] In one aspect of the invention, an armrest includes an arm support attached to a seating unit such as a chair. The upper end of the support has outer flanges and a center rib defining a pair of parallel channels. An arm and cushion are pivotally mounted to the arm support. The arm has outer ribs that align with the pair of channels. When the arm is pivoted from the vertical position to the horizontal position, the first and second outer ribs substantially fill the pair of channels. In doing so, any cavities or crevices created in the pivot joint are filled, minimizing any potential pinch area. In a preferred embodiment, the channels are designed with a lateral width that is small enough to allow only very small objects from being inserted into them.

[0007] In another aspect of the present invention, an armrest assembly includes an arm support having a forwardly curving front surface. The arm is pivotally attached to the arm support and has a bottom surface that is curved in a downward direction. The front surface of the arm support and bottom surface of the arm are thus curved in opposed directions and relatively convexly towards each other. When the arm is moved between a substantially vertical position and a substantially horizontal position, the angle between the two surfaces remains relatively open. That is to say, that a line drawn at the tangent point on the bottom surface and a line drawn at the tangent point on the front surface at the intersection point of the two surfaces, defines an angle when viewed from the side that does not significantly close. This angle is designed to provide a self-clearing effect and prevent the pinching of objects between the bottom surface and the front surface during rotation of the arm.

[0008] In yet another aspect of the present invention, an armrest assembly for a seating unit includes an arm support, and an arm pivotally attached to the arm support. The pivot attachment includes a pivot pin and a bushing. The bushing is pressed onto the pin and the pin is then inserted into aligned apertures on the arm support and arm. The arm also has a counterbore that acts as a stop for the bushing and traps the bushing between the head of the pivot pin and the counterbore. The bushing expands as it is compressed longitudinally during assembly, which creates friction and minimizes looseness within the pivot connection.

[0009] These and other features, advantages, and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.

[0010] FIG. 1 is a side view of a chair including an armrest assembly embodying the present invention;

[0011] FIG. 2 is a cross-sectional view taken along the line 2-2 in FIG. 1;

[0012] FIG. 3 is an exploded view of FIG. 2;

[0013] FIG. 4 is a perspective view of the armrest assembly embodying the present invention with the armrest oriented in a substantially vertical position;

[0014] FIG. 5 is an exploded view of the armrest assembly in FIG. 4.

[0015] FIG. 6 is a side view of the armrest assembly showing the arm oriented in both a substantially horizontal position and a substantially vertical position and showing the angle created between the arm and arm support;

[0016] FIG. 7 is a side view of the arm including the plunger assembly and cushion of the armrest of the present invention;

[0017] FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 7;

[0018] FIG. 9 is an exploded view of FIG. 8;

[0019] FIG. 10 is a cross-sectional view taken along line 10-10 in FIG. 6 showing the arm in a substantially vertical position; and

[0020] FIG. 11 is a cross-sectional view taken along line 11-11 in FIG. 6 showing the arm in a substantially horizontal position.

[0021] For purposes of description herein, the terms upper, lower, right, left, rear, front, vertical, horizontal, and derivatives thereof shall relate to the invention as oriented in FIG. 1 from the perspective of a person seated in the chair. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as unnecessarily limiting, unless the claims expressly state otherwise.

[0022] An armrest assembly 20 (FIGS. 1-3) embodying the present invention includes an armrest support 22 having an upper end 24, an arm assembly including an arm 26, a cushion 28, and a detent system including a plunger 58 and a spring 64. Arm 26 is attached to upper end 24 of arm support 22 by a pivot connection. In the preferred embodiment the arm and arm support are made of a glass filled nylon. The pivot connection includes a pivot pin 30, a bushing 32, and a screw 34 (FIGS. 2 and 3). Bushing 32 is installed on an end of pivot pin 30 and pivot pin 30 is then inserted into aligned apertures 33 and 35 on the arm support and aperture 37 on the arm. Screw 34 is then inserted into aperture 33 and threaded into a cavity 36 on pivot pin 30 to securely hold the pivot connection. Aperture 37 on arm 26 has an internal counterbore 54 (FIG. 3). Bushing 32 is made of a elastomeric material, which allows it to be compressed between counterbore 54 and a head 56 on pivot pin 30 when screw 34 is tightened (FIG. 2). When bushing 32 is compressed, it expands laterally and friction within the pivot connection is increased. When bushing 32 is compressed, the arm is also biased away from head 56 of pivot pin 30 to minimize looseness or slop within the pivot connection.

[0023] Armrest assembly 20 further includes a detent system which includes a plunger 58 having a lead end 60 and a bulb end 62, and a spring 64 that is slid on to plunger 58 from lead end 60 in a sleeve-like manner (FIGS. 8 & 9). Plunger 58 and spring 64 fit within a plunger hole 66 on arm 26 (FIGS. 5 & 9). Within plunger hole 66 there is an annular flange 68 defining a smaller internal hole 70. Lead end 60 of plunger 58 has a chamfered tip 72 and a radial flange 73. When the assembled plunger and spring are pushed through plunger hole 66, chamfered tip 72 is able to push through internal hole 70, but radial flange 73 contacts annular flange 68 preventing plunger 58 from being pulled back through and out of internal hole 70.

[0024] Arm support 22 has a notch 74 on one of the first and second outer flanges 38 and 40 (FIG. 5). When arm 26 is rotated from a substantially horizontal position to a substantially vertical position, bulb end 62 of plunger 58 moves into notch 74 and holds arm 26 in a substantially vertical or up position (FIG. 10). As bulb end 62 moves into notch 74 there is an audible detent to inform the user that the arm is in the proper up position. When arm 26 is rotated from a substantially vertical position to a substantially horizontal position, bulb end 62 tucks into plunger hole 66 allowing the arm to rotate freely without interference by plunger 58 (FIG. 11).

[0025] Upper end 24 of arm support 22 has first and second outer flanges 38 and 40, and a center rib 42 (FIGS. 3-5). The first and second outer flanges and the center rib define first and second channels 44 and 46. Arm 26 has laterally spaced first and second outer ribs 48 and 50. The arm and arm support are designed such that as the armrest is moved between a substantially horizontal and a substantially vertical position (FIGS. 4 & 6) first and second outer ribs 48 and 50 on arm 26 substantially fill first and second channels 44 and 46 on arm support 22, and center rib 42 on arm support 22 intermeshes with outer ribs 48 and 50 to substantially fill the space between them. In doing so, any cavities or crevices created within the pivot joint are substantially filled and any potential pinch areas are minimized. When the arm is in the substantially horizontal position, channels 44 and 46 and the space between the outer ribs is visible to the user. The channels and space are designed to allow only very small objects to fit within them. In the preferred embodiment, the width of the channels and of the space is preferably inch or less.

[0026] Armrest assembly 20 further includes a bottom surface 76 on arm 26 that is curved in a downward direction, and a forwardly curving front surface 78 on arm support 22. The curves are designed such that an angle 80 created between bottom surface 76 and front surface 78 at the intersection point of the two curves remains substantially open during movement of the arm (FIG. 6). Viewing armrest 20 from the side, the angle 80 formed by a line drawn at the tangent point on bottom surface 76, and a corresponding line drawn at the tangent point on front surface 78 drawn at the intersection point between the two curves, does not substantially close during rotation of the arm from the vertical to horizontal position. Bottom surface 76 and front surface 78 are curved in opposed directions and curved relatively convex towards each other so that, as the intersection point moves along the surfaces during rotation of the armrest, the surfaces diverge from one another and angle 80 formed by the tangent lines remains open. When arm 26 is oriented to the substantially horizontal position angle 80 is slightly smaller than angle 80 when arm 26 is oriented to the substantially vertical position (FIG. 6). In both the substantially vertical and substantially horizontal positions, angle 80 is at least 90 degrees and preferably at least 95 degrees throughout the range of motion for the arm. Although the angle may be slightly smaller in one position or the other, a self-clearing condition is created between arm 26 and arm support 22 by never allowing the angle to be reduced below this optimal minimum. The self-clearing effect is essentially where the two surfaces are never in such a relationship to one another so as to create an angle between them small enough to be able to grab or pinch an object between them. Instead, the relationship between the two surfaces actually pushes-out or self-clears objects away from the intersection point.

[0027] The armrest assembly of the present invention is designed such that a seated user can position the arms in a substantially horizontal position for use as a support for the user's arm. The armrest is then repositionable to a substantially vertical position so that the user can move the arms up and out of the way if so desired.

[0028] In the foregoing description, those skilled in the art will readily appreciate that modifications may be made to the invention without departing from the concepts disclosed herein. Such modifications are to be considered as included in the following claims, unless these claims by their language expressly state otherwise.