Patent Description:
Aircraft braking systems typically employ a plurality of brake discs alternately splined to the wheel and axle of an aircraft. The plurality of brake discs include rotors and stators that are compressed to slow or stop the rotation of the rotors and associated wheel. In this regard, torsional forces are transferred between the axle and the stators at various connection points thereof. <CIT> describes a shield attachment device.

A braking arrangement is disclosed and defined in claim <NUM>, comprising a torque plate comprising a torque tube and a back leg, an end plate comprising a torque pocket, a torque button comprising a head portion and a shaft portion, wherein the head portion is configured to extend at least partially into the torque pocket and the shaft portion is configured to extend through an aperture disposed in the back leg, and characterized by a bushing configured to be removably coupled between the shaft portion of the torque button and the back leg of the torque plate.

In various embodiments, the torque tube comprises an annular barrel.

In various embodiments, the back leg comprises an annular plate.

In various embodiments, an outer surface of the bushing is configured to contact the back leg and an inner surface of the bushing is configured to contact the shaft portion of the torque button.

In various embodiments, the bushing is further configured to be received at least partially into the aperture.

In various embodiments, the bushing is configured to surround the shaft portion of the torque button.

In various embodiments, a total length of the bushing is less than a total length of the shaft portion of the torque button.

In various embodiments, the torque plate comprises a first material and the bushing comprises a second material, wherein the second material is softer than the first material.

In various embodiments, the first material is titanium.

A torque plate arrangement is disclosed, comprising a torque plate comprising a torque tube defining a first central axis and a back leg, the back leg comprises an aperture defining a second central axis, a bushing configured to be received by the aperture, and a torque button comprising a head portion and a shaft portion, wherein the shaft portion is configured to be received by the bushing.

In various embodiments, the first central axis is substantially parallel to the second central axis.

In various embodiments, the torque button comprises a first material and the bushing comprises a second material, wherein the second material is softer than the first material.

In various embodiments, the torque plate is made of titanium.

In various embodiments, the shaft portion of the torque button comprises a through hole for receiving a pin.

A method for assembling a braking arrangement is disclosed, comprising moving a bushing into an aperture disposed in a back leg of a torque plate, moving a shaft portion of a torque button into the bushing, and moving an end plate over a torque tube of the torque plate.

In various embodiments, the method further comprises moving a head portion of the torque button into a torque pocket disposed in the end plate.

In various embodiments, the step of moving the end plate over the torque tube includes moving the end plate parallel to a central axis of the torque plate, and the step of moving the head portion of the torque button into the torque pocket is performed in response to moving the end plate parallel to the central axis of the torque plate.

The accompanying drawings illustrate various embodiments employing the principles described herein and are a part of this specification. The illustrated embodiments are meant for description only, and they do not limit the scope of the claims, and in which:.

The detailed description of various embodiments herein makes reference to the accompanying drawings, which show various embodiments by way of illustration. Also, any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full, and/or any other possible attachment option.

As used herein, a first component that is "radially outward" of a second component means that the first component is positioned at a greater distance away from a common axis than the second component. A first component that is "radially inward" of a second component means that the first component is positioned closer to the common axis than the second component. In the case of components that rotate circumferentially about a common axis, a first component that is radially inward of a second component rotates through a circumferentially shorter path than the second component. As used herein, "distal" refers to the direction outward, or generally, away from a reference component. As used herein, "proximal" and/or "proximate" refer to a direction inward, or generally, towards the reference component. All ranges may include the upper and lower values, and all ranges and ratio limits disclosed herein may be combined. Unless specifically stated otherwise, reference to "a," "an" or "the" may include one or more than one and reference to an item in the singular may also include the item in the plural.

Torque plates can experience wear at the contact surfaces with the torque button, which is typically manufactured using a tougher material than the torque plate. Wear of the torque plate can lead to an unserviceable condition and, ultimately, the scrapping of the torque plate. Use of a sacrificial bushing would allow wear to occur and the bushing to be replaced as desired to allow the torque plate to remain in service. The present disclosure provides, in various embodiments, a braking arrangement including a torque plate, a torque button, and a sacrificial bushing disposed therebetween. The bushing is configured to be replaced as desired, thereby tending to allow the torque plate and/or torque button to remain in service.

Referring to <FIG>, in accordance with various embodiments, an aircraft <NUM> is illustrated. The aircraft <NUM> includes landing gear, which may include a left main landing gear <NUM>, a right main landing gear <NUM> and a nose landing gear <NUM>. The landing gear support the aircraft <NUM> when it is not flying, allowing the aircraft <NUM> to taxi, take off and land without damage. While the disclosure refers to the three landing gear configurations just described, the disclosure nevertheless contemplates any number of landing gear configurations. Referring now to <FIG>, there is schematically depicted a brake mechanism <NUM> configured for use on a landing gear, such as, for example, each of the left main landing gear <NUM> and the right main landing gear <NUM> described above with reference to <FIG>. In various embodiments, the brake mechanism is mounted relative to an axle <NUM> for use with a wheel <NUM> disposed on and configured to rotate about the axle <NUM> via one or more bearing assemblies <NUM>. A central axis <NUM> extends through the axle <NUM> and defines a center of rotation of the wheel <NUM>. A torque plate <NUM> (sometimes referred to as a torque tube) is aligned concentrically with the wheel <NUM>, which is rotatable relative to the torque plate <NUM>.

The brake mechanism <NUM> includes a piston housing assembly <NUM>, a pressure plate <NUM> disposed adjacent the piston housing assembly <NUM>, an end plate <NUM> positioned a distal location from the piston housing assembly <NUM>, and a plurality of rotor disks <NUM> interleaved with a plurality of stator disks <NUM> positioned intermediate the pressure plate <NUM> and the end plate <NUM>. The pressure plate <NUM>, the plurality of rotor disks <NUM>, the plurality of stator disks <NUM> and the end plate <NUM> together form a brake stack <NUM> (or brake heat sink). The pressure plate <NUM>, the end plate <NUM> and the plurality of stator disks <NUM> are connected to the torque plate <NUM> and remain rotationally stationary relative to the axle <NUM>. The plurality of rotor disks <NUM> are connected to the wheel <NUM> and rotate relative to the pressure plate <NUM>, the end plate <NUM> and the plurality of stator disks <NUM>.

The torque plate <NUM> may include an annular barrel or torque tube <NUM> and an annular plate or back leg <NUM>. The back leg <NUM> is disposed at an end distal from the piston housing assembly <NUM> and may be made monolithic with the torque plate <NUM>, as illustrated in <FIG>, or may be made as a separate annular piece and suitably connected to the torque tube <NUM>. The torque plate <NUM> has a plurality of circumferentially spaced and axially extending splines <NUM> disposed on an outer surface of the torque tube <NUM>. The plurality of stator disks <NUM> and the pressure plate <NUM> include notches or slots <NUM> on an inner periphery of the disks and the plate for engagement with the splines <NUM>, such that each disk and the plate are axially slidable with respect to the torque tube <NUM>. The end plate <NUM> is suitably connected to the back leg <NUM> of the torque plate <NUM> and is held non-rotatable, together with the plurality of stator disks <NUM> and the pressure plate <NUM>, during a braking action. Torque plate <NUM> may extend through the end plate <NUM>. Torque plate <NUM> may be an annular plate. The plurality of rotor disks <NUM>, interleaved between the pressure plate <NUM>, the end plate <NUM> and the plurality of stator disks <NUM>, each have a plurality of circumferentially spaced notches or slots <NUM> along an outer periphery of each disk for engagement with a plurality of torque bars <NUM> that are secured to or made monolithic with an inner periphery of the wheel <NUM>.

An actuating mechanism for the brake mechanism <NUM> includes a plurality of piston assemblies, circumferentially spaced around a piston housing <NUM> (only one piston assembly is illustrated in <FIG>). Each of the plurality of piston assemblies includes a piston <NUM> configured to apply a load against the pressure plate <NUM>. Upon actuation, the plurality of piston assemblies affect a braking action by urging the pressure plate <NUM> and the plurality of stator disks <NUM> into frictional engagement with the plurality of rotor disks <NUM> and against the end plate <NUM>. Fluid or hydraulic pressure, mechanical springs or electric actuators, among other mechanisms, may be used to actuate the plurality of piston assemblies. Through compression of the plurality of rotor disks <NUM> and the plurality of stator disks <NUM> between the pressure plate <NUM> and the end plate <NUM>, the resulting frictional contact slows or stops or otherwise prevents rotation of the wheel <NUM>. The plurality of rotor disks <NUM> and the plurality of stator disks <NUM> are fabricated from various materials, such as ceramic matrix composites, that enable the brake disks to withstand and dissipate the heat generated during and following a braking action.

With respect to <FIG>, elements with like element numbering, as depicted in <FIG>, are intended to be the same and will not necessarily be repeated for the sake of clarity.

With combined reference to <FIG> and <FIG>, a plurality of torque buttons <NUM> may be disposed between torque plate <NUM> and end plate <NUM>. Torque buttons <NUM> may be circumferentially spaced around back leg <NUM>. Torque buttons <NUM> may extend axially (i.e., parallel central axis <NUM>) from back leg <NUM> towards piston housing <NUM>. Each torque button <NUM> may extend into an axially adjacent (i.e., referring to a direction parallel to central axis <NUM>) torque pocket <NUM> disposed in end plate <NUM>. Each torque button <NUM> may be generally concentrically aligned with its associated torque pocket <NUM>. In this regard, brake mechanism <NUM> may comprise a plurality of torque button <NUM> / torque pocket <NUM> pairs. In this manner, torsional forces may be transferred between end plate <NUM> and back leg <NUM>. State differently, each torque button <NUM> and associated torque pocket <NUM> may create a mechanical interference that prevents rotation of end plate <NUM> about central axis <NUM> with respect to back leg <NUM>.

With respect to <FIG>, elements with like element numbering, as depicted in <FIG> and <FIG>, are intended to be the same and will not necessarily be repeated for the sake of clarity.

With combined reference to <FIG>, each torque button <NUM> may comprise a head portion <NUM> and a shaft portion <NUM> extending from the head portion <NUM>. In various embodiments, the shaft portion <NUM> and the head portion <NUM> are in concentric alignment. In various embodiments, the head portion <NUM> is a round plate. In various embodiments, the head portion <NUM> is an annular plate. Various forces (e.g., torsional forces and/or radial forces) are transmitted through torque button <NUM> during braking operations. More particularly, these forces may be transmitted between torque plate <NUM> and end plate <NUM> via torque button <NUM>. Shaft portion <NUM> extends through aperture <NUM> disposed in back leg <NUM>. In this regard, repeated operation of the brake mechanism tends to wear and/or deform the back leg <NUM> at the location of aperture <NUM>. In this regard, a bushing <NUM> is provided to prevent wear of back leg <NUM> at aperture <NUM> during operation of the brake mechanism. Depending on the material properties of torque button <NUM>, bushing <NUM> may similarly be provided to prevent wear of torque button <NUM> during operation of the brake mechanism.

In various embodiments, torque plate <NUM> is made of a material which is softer than that of torque button. For example torque plate <NUM> may be made of a first material such as titanium for example (e.g., cast titanium), and torque button <NUM> may be made of a second material such as steel for example. While the Brinell hardness of steel can vary with heat treatment and alloy composition, steel is typically harder than titanium. Thus, because the material of torque button <NUM> is generally tougher than the material of torque plate <NUM>, torque button <NUM> may tend to deform torque plate <NUM> when forces are being transmitted therebetween. In this regard, bushing <NUM> may be removably coupled between torque plate <NUM> and torque button <NUM> as a sacrificial part that can be replaced after bushing <NUM> becomes worn as desired. Bushing <NUM> may be made of any suitable material, such as a bronze alloy, such as nickel aluminum bronze. The material of the bushing <NUM> may be softer than the material of torque plate <NUM>. In this manner, because the material of bushing <NUM> is softer than the material of torque plate <NUM>, bushing <NUM> may protect torque plate <NUM> from becoming deformed by torque button <NUM>.

In various embodiments, torque plate <NUM> may conversely be made of a material which is harder than that of torque button <NUM>. In this regard, torque button <NUM> may tend to be deformed by torque plate <NUM> when forces are transmitted therebetween. In this regard, bushing <NUM> may be made of a material that is softer than the material of torque button <NUM> to protect torque button <NUM> from becoming deformed.

In various embodiments, bushing <NUM> is shaped to be a hollow cylindrical shaft. In various embodiments, bushing <NUM> is shaped like a top hat (i.e., comprising a hollow cylindrical shaft with a radially outwardly extending flange disposed at an end thereof). Bushing <NUM> may be placed over the shaft portion <NUM>. Stated differently, bushing <NUM> may be configured to receive shaft portion <NUM>. Bushing <NUM> may be configured to circumferentially surround the shaft portion <NUM>. Bushing <NUM> and shaft portion <NUM> may be in concentric alignment when bushing <NUM> is installed onto torque button <NUM>. Bushing <NUM> may be received by aperture <NUM>. The outer surface of bushing <NUM> may contact back leg <NUM> and the inner surface of bushing <NUM> may contact shaft portion <NUM>.

Head portion <NUM> of torque button <NUM> may be configured to extend at least partially into the torque pocket <NUM>. Head portion <NUM> may be substantially flush with end plate <NUM> when head portion <NUM> is in the installed position in torque pocket <NUM>. However, head portion <NUM> may extend at least partially into torque pocket <NUM> such that end plate <NUM> and head portion <NUM> are not substantially flush, in accordance with various embodiments. Shaft portion <NUM> may be configured to extend through aperture <NUM> of back leg <NUM>. Aperture <NUM> may define a central axis <NUM>. Central axis <NUM> may be substantially parallel to central axis <NUM> (see <FIG>).

With reference to <FIG>, a perspective view of a torque button <NUM> and bushing <NUM> in their respective installed positions is illustrated, in accordance with various embodiments. In various embodiments, shaft portion <NUM> comprises a through hole <NUM> configured to receive a pin <NUM> (see <FIG>) for securing torque button <NUM> to torque plate <NUM>.

With reference to <FIG>, an assembly view of torque button <NUM> and bushing <NUM> is illustrated, in accordance with various embodiments. In various embodiments, a total length <NUM> of bushing <NUM> may be less than a total length <NUM> of shaft portion <NUM>.

With combined reference to <FIG> and <FIG>, to assemble the braking arrangement, bushing <NUM> may be moved into aperture <NUM>. In various embodiments, bushing <NUM> is press fit into aperture <NUM>. In various embodiments, bushing <NUM> is placed into aperture <NUM> in a non-press fit design, wherein the outer diameter of bushing <NUM> is less than the inner diameter of aperture <NUM> such that bushing <NUM> is loosely disposed in aperture <NUM>. In this manner, bushing <NUM> may be sufficiently held in place between the head portion <NUM> of torque button <NUM> and the terminus of shaft portion <NUM> opposite head portion <NUM>; for example bushing <NUM> may be mechanically blocked from sliding off shaft portion <NUM> by pin <NUM> or the like. Before or after the bushing <NUM> is moved into aperture <NUM>, shaft portion <NUM> may be moved into the bushing <NUM>. In various embodiments, shaft portion <NUM> is press fit into bushing <NUM>. End plate <NUM> may be moved over torque tube <NUM> (see <FIG>). As the end plate <NUM> is slide (parallel central axis <NUM>) over torque tube <NUM> towards back leg <NUM>, head portion <NUM> may enter into torque pocket <NUM>. End plate <NUM> may be moved towards back leg <NUM> until head portion <NUM> contacts the back surface of torque pocket <NUM>.

However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the invention.

The scope of the invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more. " It is to be understood that unless specifically stated otherwise, references to "a," "an," and/or "the" may include one or more than one, and that reference to an item in the singular may also include the item in the plural.

Moreover, where a phrase similar to "at least one of A, B, and C" is used in the claims, it is intended that the phrase be interpreted to mean that A alone may be present in an embodiment, B alone may be present in an embodiment, C alone may be present in an embodiment, or that any combination of the elements A, B, and C may be present in a single embodiment; for example, A and B, A and C, B and C, or A and B and C. Different cross-hatching is used throughout the figures to denote different parts, but not necessarily to denote the same or different materials.

For example, steps that may be performed concurrently or in different order are only illustrated in the figures to help to improve understanding of embodiments of the present, representative invention.

Any reference to attached, fixed, connected, or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Surface shading lines may be used throughout the figures to denote different parts or areas, but not necessarily to denote the same or different materials.

Claim 1:
A braking arrangement, comprising:
a torque plate (<NUM>) comprising a torque tube and a back leg;
an end plate (<NUM>) comprising a torque pocket;
a torque button (<NUM>) comprising a head portion and a shaft portion, wherein the head portion is configured to extend at least partially into the torque pocket and the shaft portion is configured to extend through an aperture disposed in the back leg; and characterized by
a bushing configured to be removably coupled between the shaft portion of the torque button (<NUM>) and the back leg of the torque plate (<NUM>).