Patent Description:
Vehicle seats such as aircraft passenger seats are commonly equipped with assemblies such as armrests, tray tables, leg rests, and seat backs that are adjustable for passenger comfort and personnel use. These assemblies typically include moving parts for adjustability and stowage between uses. The components that facilitate the adjustability of such assemblies and arrangements are expected to provide long service lives.

Moving elements that are subject to more frequent use are exposed to higher wear and even abuse. For example, pivoting armrests of airline passenger seats are likely handled and adjusted several times by every passenger that uses a particular seat. An armrest may be raised and lowered for courtesy each time another passenger using a nearby seat enters and exits a seating row. A typical armrest pivots about a single mounting point in a cantilever fashion. The expectation that an armrest maintains its position once adjusted by a passenger is typically met by a pivoting joint that applies an appropriate amount of friction to permit adjustment and assure stability.

Such armrests ultimately require maintenance and repair, particularly in components where friction and movement occur and thus wear tends to accumulate. As wear occurs in the pivoting joints of armrests, it is undesirable to replace an entire passenger seat or other major assembly or even disassemble such an assembly to any great extent. Airline operators thus prefer to conduct maintenance and repair operations with as little interruption to aircraft use as feasible.

Any mounting and pivoting mechanism that attaches a pivoting element to a more fixed host structure, and that applies friction against relative movement, is likely to require maintenance and repair. It is preferable to minimize the costs of replacement parts and the required skill level for repair operations, while at once assuring a repaired mechanism is returned to an expected performance level once a maintenance operation is complete.

Therefore, what is needed is an armrest assembly easily installed, maintained, and removed while in service, while also maintaining a discreet armrest connection. <CIT> relates to an adjustable armrest assembly.

The present invention provides an armrest assembly including a fixed support member provided with a bore defining an axis of rotation, a pivot block provided with a shaft rotatably engaging the bore, and an armrest coupled to the pivot block. A retention pin retains the pivot block to the fixed support member. The retention pin is installed through the fixed support member, perpendicular to the axis of rotation, and is received in an annular groove formed in the shaft of the pivot block. The fixed support member and the pivot block are provided with mating stop blocks configured to limiting pivoting of the pivot block relative to the fixed support member.

In some embodiment, the fixed support member is provided with separate stop blocks diametrically opposed about the bore, the pivot block is provided with separate stop blocks diametrically opposed about the shaft, the stop blocks of the pivot block are configured to engage the stop blocks of the fixed support member in a first configuration to prevent further upward pivoting of the pivot block relative to the fixed support member, and the stop blocks of the pivot block are configured to engage the stop blocks of the fixed support member in a second configuration to prevent further downward pivoting of the pivot block relative to the fixed support member.

In some embodiments, the stop blocks of the pivot block and the stop blocks of the fixed support member are interdigitated.

In some embodiments, the armrest assembly further includes a washer disposed between the fixed support member and the pivot block, the washer positioned radially outward of the interdigitated stop blocks of the pivot block and the fixed support member.

In some embodiments, the fixed support member is a spreader defining opposing sides and the pivot block bears against one of the opposing sides.

In some embodiments, an internally threaded bore is formed in the fixed support member, wherein the retention pin is externally threaded and theadably engages in the internally threaded bore.

In some embodiments, an opening to the internally threaded bore is positioned below the armrest such that the retention pin, when installed, is concealed from view when the armrest is fully lowered.

In some embodiments, the pivot block is configured to rotate relative to the fixed support member to move the armrest between a first position in which the armrest is substantially horizontal and a second position in which the armrest is substantially vertical.

Such description refers to the included drawings, which are not necessarily to scale, and in which some features may be exaggerated, and some features may be omitted or may be represented schematically in the interest of clarity. Like reference numbers in the drawings may represent and refer to the same or similar element, feature, or function. In the drawings:.

In the following detailed description of embodiments of the instant inventive concepts, numerous specific details are set forth to provide a more thorough understanding of the inventive concepts.

Broadly speaking, embodiments of the inventive concepts disclosed herein are directed to armrest assemblies easily installed and removed while in service, while also maintaining a discreet connection. In an embodiment, the armrest assembly includes a pivot block that holds the armrest itself and is coupled to a support member, for instance a fixed seat spreader. The pivot block and spreader have mating stop block features that interact to allow the armrest to rotate while being restrained from motion in the upper and lower positions. A central shaft common to the pivot block allows for rotation. A retention pin is installed perpendicular to the axis of rotation through the spreader and grooved central shaft. The groove in the shaft retains the pivot block assembly while allowing for rotation.

Referring to <FIG> and <FIG>, a non-limiting example of an armrest assembly is shown generally at reference numeral <NUM>. As compared to conventional clevis type armrests where the armrest captures the mating feature on both sides, in the present armrest assembly <NUM> there is no visible pivot point, thus providing an elegant retention solution.

Components of the armrest assembly <NUM> generally include a fixed frame member <NUM>, a pivot block <NUM> rotatably coupled to the fixed frame member <NUM>, and an armrest <NUM> coupled to and carried by the pivot block <NUM>. In a particular embodiment in which the armrest assembly is installed on an economy class type aircraft passenger seat, the fixed frame member <NUM> may be a spreader as shown. Known to those skilled in the art of aircraft passenger seats, a spreader is a vertically oriented support member disposed at the ends of a seat row and between adjacent seats that functions to receive lateral beam tubes supporting the seat bottoms. In some spreader configurations, a lower portion of the spreader forms legs while the upper portion supports a pivotally attached armrest in a clevis type construction as mentioned above. The spreader is typically constructed from aluminum for strength and weight savings and may be foraminous for further weight savings.

The armrest is configured to pivot between a use position as shown in <FIG> and <FIG>, and a stowed position as shown in <FIG>. In the use position, the armrest <NUM> is oriented substantially, and in the stowed position the armrest is oriented substantially vertical. The upper end of the spreader is typically positioned to the side of its respective seat back such that the armrest <NUM>, when stowed, resides along the seat back and out of the way to facilitate seat ingress and egress. Although not limiting, the typical range of motion of the armrest is about <NUM> degrees and the armrest is moved between the stowed and deployed positions manually. The armrest <NUM> is elongated and may include padding or a padded arm cap.

Referring to <FIG> and <FIG>, the fixed support member <NUM> defines an upper end configured to attach the pivot block <NUM>. Half of the thickness of the uppermost portion of the assembly is attributable to the thickness of the fixed support member <NUM>, while the other half is attributable to the thickness of the pivot block <NUM>, in substantially equal thickness or halves, such that the total thickness of the uppermost portion of the assembly is low profile and substantially equal to the thickness of lower portions of the fixed support member <NUM>. A ledge <NUM> defined proximate the upper end of the fixed support member <NUM> is contoured to complement the contouring of the of the pivot block, and in some cases may function as a mechanical stop to prevent further downward pivoting of the armrest. As shown, the forward end of the ledge <NUM> contours away from the overlying armrest to preclude a finger pinch when the armrest is in downward-most position.

A bore <NUM> provided on one side of the fixed support member <NUM> opens toward the pivot block <NUM> and defines a horizontal axis of rotation of the armrest shown at reference numeral <NUM>. The bore <NUM> receives a concentric shaft <NUM> provided on the facing side of the pivot block <NUM>. The shaft <NUM> rotatably engages the bore <NUM>. The shaft <NUM> defines an annular groove <NUM> at one end configured to receive a portion of a retention pin <NUM> retaining the pivot block <NUM> to the fixed support member <NUM>. A second, smaller diameter bore <NUM> opens on one side of the fixed support member <NUM>. In some embodiments, the externally threaded retention pin <NUM> is threadably engaged in the internally threaded second bore <NUM>. The retention pin <NUM> may include a head <NUM> forming a tool pattern configured to receive a corresponding tool for advancing and withdrawing the retention pin relative to the opening, such as a hex or star pattern.

Each of the fixed support member <NUM> and the pivot block <NUM> define stop blocks that interact, mate or otherwise engage to control rotation of the pivot block <NUM> relative to the fixed support member <NUM>. As shown in <FIG>, the fixed support member <NUM> is provided with separate first and second stop blocks <NUM>, <NUM> diametrically opposed about the bore <NUM>. As shown in <FIG>, the pivot block <NUM> is provided with corresponding first and second stop blocks <NUM>, <NUM> diametrically opposed about the shaft <NUM>. With the pivot block <NUM> rotatably coupled to the fixed support member <NUM>, the first and second stop blocks <NUM>, <NUM> of the fixed support member <NUM> and the first and second stop blocks <NUM>, <NUM> of the pivot block <NUM> are interdigitated such that stop block <NUM> is positioned between one side of stop blocks <NUM> and <NUM>, and stop block <NUM> is positioned between the opposing side of stock bocks <NUM> and <NUM>.

Each stop block <NUM>, <NUM>, <NUM>, <NUM> defines opposing faces. In use, when the armrest is pivoted fully downward, stock block <NUM> engages stop block <NUM> and stop block <NUM> engages stop block <NUM> thereby preventing further downward pivoting. When the armrest is pivotally fully upward, stop block <NUM> engages stop block <NUM> and stop block <NUM> engages stop block <NUM> thereby preventing further upward pivoting. The amount of rotation of the pivot block <NUM> relative to the fixed support member <NUM>, and consequently the angular travel of the armrest, can be customized based one or more of the relative positions of the stop blocks, spacing between stop blocks, dimensions of the stop blocks, etc. In each of the fully lowered and fully raised positions of the armrest, the first and second stop blocks <NUM>, <NUM> of the pivot block <NUM> preferably simultaneously engage the first and second stop blocks <NUM>, <NUM> of the fixed support member <NUM> for stability.

In some embodiments, a friction-enhancing or friction-reducing washer <NUM> is positioned concentric with the bore <NUM> and shaft <NUM>. One face of the washer <NUM> faces and engages the fixed support member <NUM> while the opposing face faces and engages the pivot block <NUM>. An inner diameter of the washer <NUM> is dimensioned such that the washer is positioned radially outward of the stop blocks <NUM>, <NUM>, <NUM>, <NUM>, while the outer diameter of the washer is dimensioned to fit within the bounds of the pivot block <NUM> and fixed support member <NUM>, thereby substantially concealing the washer from view.

Referring to <FIG>, a first end of the pivot block <NUM> forms the portion configured to rotatably engage the fixed support member <NUM>, while the second end forms an elongated support member <NUM> for attaching the armrest. In some embodiments, the first and second ends of the pivot block <NUM> are integrally formed.

Referring to <FIG>, the retention pin <NUM> retains the pivot block <NUM> to the fixed support member <NUM>. The second bore <NUM> is positioned such that the retention pin <NUM> is installed through the fixed support member <NUM> perpendicular to the axis of rotation <NUM>. When installed, a portion of the retention pin <NUM> is disposed in the annular groove <NUM> formed in the shaft <NUM> of the pivot block <NUM>. As shown, the shaft <NUM> advances into the bore of the fixed support member such that the annular groove <NUM> is positioned at the inner opening of the second bore <NUM>. In this position, the retention pin <NUM> passes through the annular groove <NUM>, tangentially, thereby preventing the pivot block <NUM> from being pulled apart from the fixed support member <NUM>. The tangential orientation of the retention pin <NUM> prevents axial movement of the shaft <NUM> while allowing rotational movement. To detach the pivot block <NUM> from the fixed support member <NUM>, the retention pin <NUM> is withdrawn until the retention pin is clear of the annular groove <NUM>, allowing the pivot block <NUM> to be pulled apart from the fixed support member <NUM>.

Referring to <FIG>, fasteners <NUM> securing the armrest <NUM> to the pivot block <NUM> are provided on the bottom of the armrest to conceal the fasteners from view when the armrest is lowered. In addition, the second bore <NUM> is concealed from view beneath the armrest <NUM> when the armrest is lowered. As such, the single fastener retaining the pivot block <NUM>, and thus the armrest <NUM>, to the fixed support member <NUM> is concealed from view beneath the lowered armrest to conceal the retention pin and pivot point.

Claim 1:
An armrest assembly (<NUM>), comprising:
a fixed support member (<NUM>) provided with a bore (<NUM>) defining an axis of rotation;
a pivot block (<NUM>) provided with a shaft (<NUM>) rotatably engaging the bore; and
an armrest coupled to the pivot block;
wherein the armrest assembly further includes:
a retention pin (<NUM>) retaining the pivot block to the fixed support member, the retention pin installed through the fixed support member, perpendicular to the axis of rotation, and received in an annular groove (<NUM>) formed in the shaft of the pivot block; and
the fixed support member and the pivot block provided with mating stop blocks configured to limiting pivoting of the pivot block relative to the fixed support member.