Patent Description:
Aircraft windshield wiper systems are used to wipe and clean water or other debris from an aircraft windshield, allowing better visibility out the windshield for both the pilot and copilot. Windshield wiper systems include a wiper arm and a wiper blade that sweep back and forth across a windshield within specific sweep angle requirements, cleaning the windshield for the pilot and co-pilot. Many windshield wiper systems include a wash system that dispenses a fluid onto the windshield of the aircraft to aid in cleaning the windshield of the aircraft. Windshield wiper systems utilizing metallic supports have a fluid tube welded or brazed to the metallic components for providing fluid adjacent the wiper blade sweeping across the windshield. Windshield wiper systems utilizing composite supports cannot include welded or brazed fluid tubes and therefore there is a need for a solution to incorporate fluid tubes into composite support type wiper blade assemblies. <CIT> describes a wiper blade. <CIT> describes a windshield wiper system having a tubular member having a foam core.

A wiper blade for use on a windshield of an aircraft is disclosed herein and defined in claim <NUM>.

<FIG> is a side view of windshield wiper system <NUM> on aircraft windshield <NUM>. Hereinafter windshield wiper system <NUM> will be referred to as WWS <NUM>. WWS <NUM> includes wiper blade <NUM>, wiper arm <NUM>, output shaft <NUM>, actuator <NUM>, fluid source <NUM>, and fluid line <NUM>. WWS <NUM> is installed on an aircraft and WWS <NUM> is configured to clear windshield <NUM> of rain or other debris. Wiper arm <NUM> includes first end 16A positioned at a distal end of wiper arm <NUM> and second end 16B positioned at an opposite distal end of wiper arm <NUM> as first end 16A. Wiper blade <NUM> is coupled to first end 16A of wiper arm <NUM> through a coupler, discussed further below. Wiper arm <NUM> can be constructed from a polymer, a composite, a metal, or at least partially from one or more of the listed materials.

Wiper arm <NUM> is coupled to output shaft <NUM> at second end 16B of wiper arm <NUM> through a mechanical connection, such as a threaded or clamping connection. Output shaft <NUM> extends through a body portion of the aircraft adjacent windshield <NUM> but not through windshield <NUM>. Output shaft <NUM> is configured to rotate about its central axis, providing rotational energy to second end 16B of wiper arm <NUM>, which in turn forces wiper arm <NUM> and wiper blade <NUM> to traverse across windshield <NUM> in a sweeping motion. Actuator <NUM> is coupled to output shaft <NUM> within the body portion of the aircraft. Actuator <NUM> is configured to provide rotational energy to output shaft <NUM>, rotating output shaft <NUM> about its central axis. The rotation of output shaft <NUM> forces wiper arm <NUM> and wiper blade <NUM> to traverse across windshield <NUM> in a sweeping motion, therefore actuator <NUM> provides the energy necessary to drive motion of WWS <NUM>. In the embodiment shown, actuator <NUM> is a brushless direct current motor. In another embodiment, actuator <NUM> can be a brushed direct current motor or any other motor configured to provide rotational energy to output shaft <NUM>. Further, actuator <NUM> is a bi-directional motor that can operate in both directions, allowing output shaft <NUM>, wiper arm <NUM>, and wiper blade <NUM> to travel across windshield <NUM> in both directions.

In one example, fluid source <NUM> can be an impermeable vessel of any shape, size, and material that is configured to store the fluid that will be dispensed onto windshield <NUM>. In other words, fluid source <NUM> can be a leak proof container that includes a hollow interior configured to store fluids before the fluids are used by WWS <NUM>. In other examples, fluid source <NUM> can be a flow path from a portion of an engine, compressor, auxiliary power unit, or any other hot air source within the aircraft, such as for example to provide engine bleed air to WWS <NUM>. Fluid source <NUM> is positioned within the aircraft body and fluidly coupled to wiper blade <NUM> through fluid line <NUM>, discussed further below. Fluid line <NUM> extends from fluid source <NUM> to wiper blade <NUM>. Fluid line <NUM> can be a tube, channel, hose, or any other component capable of transferring a fluid from fluid source <NUM> to wiper blade <NUM>. The fluid transferring through fluid line <NUM> can be one or more of water, windshield cleaning fluid, chemical rain repellant, and hot engine bleed air, among other options. Fluid line <NUM> is configured to provide a flow path for fluid to flow from fluid source <NUM> to wiper blade <NUM>, allowing the fluid to dispense onto windshield <NUM> adjacent wiper blade <NUM>. In the embodiment shown, fluid line <NUM> is coupled to wiper blade <NUM> at approximately the center of wiper blade <NUM>, with respect to the length of wiper blade <NUM>. In another embodiment, fluid line <NUM> can be coupled to wiper blade <NUM> at any location along the length of wiper blade <NUM>.

<FIG> is a perspective view of wiper blade <NUM> of WWS <NUM>. <FIG> is a perspective view of the support member of wiper blade <NUM>. <FIG> is a close-up perspective view of wiper blade <NUM> with the rubber blade element removed for clarity. <FIG> will be discussed together. Wiper blade <NUM> includes support member <NUM>, blade element <NUM>, clips <NUM>, wash tube <NUM>, coupler <NUM>, and fastener <NUM>. Support member <NUM> is coupled to blade element <NUM> and clip <NUM> is coupled to and surrounds at least a portion of support member <NUM> and at least a portion of blade element <NUM>. Likewise, coupler <NUM> is coupled to and surrounds at least a portion of support member <NUM> and at least a portion of blade element <NUM>. Fastener <NUM> extends through blade element <NUM> and clip <NUM>, securing clip <NUM> to blade element <NUM>. Each respective component will be discussed further below.

Support member <NUM> is a structural component that provides rigidity to wiper blade <NUM> during operation of WWS <NUM>. In the embodiment shown, support member <NUM> includes a generally triangular cross-section extending the length of wiper blade <NUM>, providing stiffness and rigidity to wiper blade <NUM> to prevent undesirable deflection of wiper blade <NUM> in the sweeping directions. Further, the generally triangular cross-section reduces drag of wiper blade <NUM> during operation of WWS <NUM>. In another embodiment, support member <NUM> can include a cross-section of any shape that extends a full or partial length of wiper blade <NUM>. Support member <NUM> can be constructed from a composite material, metallic material, or polymer material, discussed in detail with reference to <FIG>. In one example, support member <NUM> can be constructed from a carbon fiber reinforced polymer, polytetrafluoroethylene (PTFE) composite material, or other comparable composite material. Support member <NUM> is coupled to blade element <NUM> through an adhesive positioned between support member <NUM> and blade element <NUM> and extending a substantial length of support member <NUM>. In one example, the adhesive used to couple support member <NUM> to blade element <NUM> is a polyurethane adhesive.

Blade element <NUM> is the component of wiper blade <NUM> that is configured to interface with windshield <NUM> to clear windshield <NUM> of water or other debris. Blade element <NUM> has a complex cross-sectional shape including a rectangular top portion and a generally triangular bottom portion configured to contact and clean windshield <NUM> on the aircraft. Blade element <NUM> can be constructed from a rubber material, such as in one example blade element <NUM> is constructed from a nitrile rubber. In some examples, blade element <NUM> can have a length that is less than a length of support member <NUM>. During the adhesion of support member <NUM> to blade element <NUM>, blade element <NUM> is stretched which causes support member <NUM> to flex into a curved configuration, conforming to the shape of windshield <NUM>. In other examples, blade element <NUM> can have the same length as support member <NUM>.

Clip <NUM> is a component of wiper blade <NUM> that is configured to provide additional attachment support between support member <NUM> and blade element <NUM>. More specifically, clip <NUM> is coupled to both support member <NUM> and blade element <NUM>, and clip <NUM> surrounds at least a portion of each of support member <NUM> and blade element <NUM>. Clip <NUM> is configured to exert a clamping force on support member <NUM> and blade element <NUM>, compressing support member <NUM> and blade element <NUM> together. Fastener <NUM> is configured to extend through only clip <NUM> and the rectangular top portion of blade element <NUM> to secure clip <NUM> to blade element <NUM>, which further secures support member <NUM> and blade element <NUM> together in compression. Fastener <NUM> does not extend through support member <NUM> in an effort to eliminate unnecessary apertures within support member <NUM>. Fastener <NUM> can extend through each clip <NUM> coupled to support member <NUM> and blade element <NUM>. As such, in an embodiment including four clips <NUM>, there will be four fasteners <NUM> securing the four clips <NUM> to support member <NUM> and blade element <NUM>. The number of fasteners <NUM> will depend on the number of clips <NUM> on wiper blade <NUM>. Fastener <NUM> can be a rivet, bolt and nut, pin and clevis, pin and clamp, among other options.

Clip <NUM> can be constructed from a metal, a polymer, or a composite material. In one example, clip <NUM> can be constructed from a spring steel or sheet metal to facilitate the clamping force exerted on support member <NUM> and blade element <NUM>. In the embodiment shown in <FIG>, wiper blade <NUM> includes four clips <NUM> coupled to support member <NUM> and blade element <NUM>. In another example, wiper blade <NUM> can include more or less than four clips <NUM> coupled to support member <NUM> and blade element <NUM>. The number of clips <NUM> coupled to wiper blade <NUM> depends on various factors, such as the length of wiper blade <NUM> and the forces exerted on wiper blade <NUM>, among other factors. In one example, wiper blade <NUM> includes two inner clips <NUM> spaced equidistance from coupler <NUM> and two outer clips <NUM> adjacent the ends of wiper blade <NUM> that are also spaced equidistance from coupler <NUM>. Further, in the example shown, there are an equal number of clips <NUM> positioned on each side of coupler <NUM>. In another example, there can be an unequal number of clips <NUM> positioned on each side of coupler <NUM>. In other examples, wiper blade <NUM> may not include any clips <NUM>, such that an adhesive positioned between support member <NUM> and blade element <NUM> secures the components together.

Coupler <NUM> is positioned at a center position with respect to a length of support member <NUM> and coupler <NUM> extends outward from support member <NUM> in a direction opposite of blade element <NUM>. Similar to clip <NUM>, coupler <NUM> is coupled to and surrounds at least a portion of support member <NUM> and at least a portion of blade element <NUM>. Coupler <NUM> is configured to couple to support member <NUM> and blade element <NUM> at one end and couple to first end 16A of wiper arm <NUM> at the other end. As such, coupler <NUM> is configured to secure wiper blade <NUM> to wiper arm <NUM> of WWS <NUM> (<FIG>). Coupler <NUM> can be coupled to wiper arm <NUM> through one or more of a rivet, bolt and nut, pin and clevis, and pin and clamp, among other options. In the embodiment shown, coupler <NUM> is constructed from a metallic material. In other embodiments, coupler <NUM> can be constructed from a polymer or a composite material, among other options.

As shown best in <FIG>, wash tube <NUM> is an aperture that extends fully through support member <NUM>, from first end 26A of support member <NUM> to second end 26B of support member <NUM>. As such, wash tube <NUM> is integral with and positioned within support member <NUM>. Wash tube <NUM> is a tubular feature extending through a central portion of support member <NUM> that allows fluids to flow through wash tube <NUM> within support member <NUM>. In the embodiment shown, wash tube <NUM> has a circular cross-sectional shape when viewing in the axial direction of wash tube <NUM>. In other embodiments, wash tube <NUM> can have any desired cross-sectional shape when viewing in the axial direction of wash tube <NUM>. Referring to <FIG> or <FIG>, wiper blade <NUM> also includes plugs <NUM> positioned at first end 26A and second end 26B of wash tube <NUM>. More specifically, plugs <NUM> are inserted within ends 26A, 26B of wash tube <NUM> and plugs <NUM> prevent fluid from flowing out through each end 26A, 26B of wash tube <NUM>. Plugs <NUM> can be coupled to wash tube <NUM> through one or more of a friction fit, an adhesive, and a composite fusion process, among other fluid tight options. In the embodiment shown, plugs <NUM> have an outer diameter that is smaller than the diameter of wash tube <NUM>, which allows plugs <NUM> to be inserted within wash tube <NUM>. In the embodiment shown, plugs <NUM> have a circular cross-sectional shape when viewing in the axial direction of plugs <NUM>. In other embodiments, plugs <NUM> can have any desired cross-sectional shape that conforms to the cross-sectional shape of wash tube <NUM>. Further, plugs <NUM> can be constructed from the same or similar composite material as support member <NUM>.

Wiper blade <NUM> also includes a plurality of nozzles <NUM> and fluid input <NUM> (<FIG>). Nozzles <NUM> are spaced along a length of support member <NUM> and nozzles <NUM> extend into support member <NUM>, providing a location in which the fluid flowing through wash tube <NUM> can dispense or exit wash tube <NUM> onto windshield <NUM> of the aircraft. In some examples, each nozzle <NUM> can be an aperture extending from an outer surface of support member <NUM> to wash tube <NUM> within the central portion of support member <NUM>. As such, wash tube <NUM> is fluidly coupled to each of the plurality of nozzles <NUM>. Nozzles <NUM> are configured to increase the pressure and velocity of the fluid as the fluid dispenses through nozzles <NUM>. In the embodiment shown, support member <NUM> includes eight nozzles <NUM> spaced along a length of support member <NUM>. In another embodiment, support member <NUM> can include more or fewer than eight nozzles <NUM> spaced along the length of support member <NUM>. The number of nozzles <NUM> will vary depending on the length of wiper blade <NUM> and the fluid requirements for each specific application. Further, nozzles <NUM> are positioned adjacent the initial sweep side of wiper blade <NUM>. In other words, if wiper blade <NUM> initially sweeps in a left direction when WWS <NUM> is activated, nozzles <NUM> are also positioned on the left side of wiper blade <NUM>. Likewise, if wiper blade <NUM> initially sweeps in a right direction when WWS <NUM> is activated, nozzles <NUM> are also positioned on the right side of wiper blade <NUM>. Positioning nozzles <NUM> on the initial sweep side of wiper blade <NUM> allows fluid to dispense onto windshield <NUM> in front of wiper blade <NUM> before wiper blade <NUM> sweeps across an area of windshield <NUM>.

Referring to <FIG>, fluid input <NUM> is an aperture that extends into support member <NUM> and fluidly connects to wash tube <NUM> within support member <NUM>. Fluid input <NUM> is positioned at approximately the center of support member <NUM> in the lengthwise direction of support member <NUM>. Fluid input <NUM> fluidly connects fluid line <NUM> (<FIG>) and wash tube <NUM>, providing a flow path for fluid to flow from fluid line <NUM> into wash tube <NUM>. More specifically, referring to <FIG>, fluid flows from fluid line <NUM> into input port <NUM>, and then the fluid flows from input port <NUM> into fluid input <NUM> of support member <NUM>. Input port <NUM> is a tube, channel, valve, orifice, or the like, that is axially aligned with fluid input <NUM> and input port <NUM> extends through and is coupled to coupler <NUM>. More specifically, input port <NUM> extends through an aperture within coupler <NUM> and input port <NUM> is coupled to coupler <NUM> through a braze or weld connection. As such, input port <NUM> and coupler <NUM> can be constructed from a metallic material, facilitating the brazed or welded connection between the components.

Further, the end of input port <NUM> extending within fluid input <NUM> of support member <NUM> is coupled to fluid input <NUM> of support member <NUM> through an adhesive connection. Brazing or welding input port <NUM> to coupler <NUM> and coupling input port <NUM> to support member <NUM> through an adhesive connection provides additional support and connection between support member <NUM> and coupler <NUM>. Input port <NUM> provides a connection and flow path between fluid line <NUM> and fluid input <NUM>, allowing fluid to flow from fluid input <NUM> through input port <NUM> and into fluid input <NUM>. As such, in operation fluid is transferred from fluid source <NUM> through fluid line <NUM>, the fluid travels through fluid line <NUM> to input port <NUM>, the fluid flows through input port <NUM> and into fluid input <NUM>, the fluid flows through fluid input <NUM> and into wash tube <NUM>, and then the fluid flows through wash tube <NUM> and dispenses through the plurality of nozzles <NUM> onto windshield <NUM> of the aircraft.

<FIG> is a close-up perspective view of an end of support member <NUM> of wiper blade <NUM> with plug <NUM> removed. In other words, plug <NUM> is shown removed from wash tube <NUM>, illustrating how plug <NUM> is inserted into each end 26A, 26B of wash tube <NUM> to prevent fluid leakage through ends 26A, 26B of wash tube <NUM>. Further, <FIG> illustrates an example material configuration for support member <NUM>. As mentioned, support member <NUM> can be constructed from a composite material, such as a carbon fiber reinforced polymer, polytetrafluoroethylene (PTFE) composite material, or other comparable composite material. The material properties listed allow wash tube <NUM> to be located within the central portion of support member <NUM> while maintaining the requisite stiffness and strength characteristics of support member <NUM>, preventing undesirable deflection of wiper blade <NUM> during operation of WWS <NUM> that can lead to under-sweep and over-sweep conditions.

In some examples, support member <NUM> can be constructed from a plurality of composite plies <NUM> stacked in a vertical direction from base <NUM> of support member <NUM> to top <NUM> of support member <NUM>. Base <NUM> of support member <NUM> is the bottom surface of support member <NUM> that is positioned adjacent and contacts a portion of blade element <NUM> (<FIG>). Top <NUM> of support member <NUM> is the upper surface or edge of support member <NUM> that is positioned adjacent the point of the triangular shaped support member <NUM>. In the vertically stacked configuration, each of the plurality of composite plies <NUM> extends in a horizontal direction from first end 26A of support member <NUM> to second end 26B of support member <NUM> (<FIG>). In other examples, support member <NUM> can be constructed from a plurality of composite plies <NUM> stacked or positioned in any direction or orientation.

Further, in some examples, at least one of the plurality of composite plies <NUM> can include cutout feature <NUM>. Cutout feature <NUM> is a notch or indentation along an edge or surface of an individual composite ply <NUM>. Further, cutout feature <NUM> can be a same or differing shape as an adjacent cutout feature <NUM> of an adjacent composite ply <NUM>. A plurality of cutout features <NUM> of the at least one of the plurality of composite plies <NUM> forms wash tube <NUM> within the central portion of support member <NUM>. In other words, cutout features <NUM> are produced during the layup process of each individual ply <NUM> of support member <NUM>. Once the plurality of composite plies <NUM> are stacked in the vertical direction, the plurality of cutout features <NUM> form wash tube <NUM> extending through a central portion of support member <NUM>. In other examples, each of the plurality of composite plies <NUM> can have a continuous, uninterrupted cross-section through a length and thickness of each individual ply <NUM>. As such, once the plurality of composite plies <NUM> are stacked in the vertical direction, support member <NUM> has a solid cross-section before wash tube <NUM> is machined into support member <NUM>. Following the layup process, wash tube <NUM> can be produced by a drilling operation from first end 26A of support member <NUM> to second end 26B of support member <NUM>. In addition, each of the plurality of nozzles <NUM> can be produced by a drilling operation from an outer surface of support member <NUM> to wash tube <NUM> within the central portion of support member <NUM>. As such, wash tube <NUM> can be produced either during the layup process of the composite plies <NUM> and support member <NUM> or wash tube <NUM> can be produced using a machining operation after the layup of support member <NUM>.

Previous windshield wiper systems with metallic supports have a wash tube welded or brazed to the metallic support member for providing fluid adjacent the wiper blade sweeping across the windshield. Windshield wiper systems with composite supports cannot include welded or brazed fluid tubes along the length of the wiper blade. WWS <NUM> including wiper blade <NUM> and wash tube <NUM> within support member <NUM> provides a solution for enabling the use of composite supports on wiper blades while also enabling the windshield wiper system to dispense fluid onto the windshield of the aircraft. Further, wash tube <NUM> being integral with and positioned within a central portion of support member <NUM> eliminates the need for a separate wash tube, reduces the number of components within the wiper blade assembly and the overall WWS <NUM>, and reduces the overall weight of WWS <NUM>. Therefore, WWS <NUM> provides the benefit of decreasing over-sweep and under-sweep by utilizing composite support member <NUM>, and also provides the capability to dispense a fluid onto windshield <NUM> of the aircraft to aid in cleaning windshield <NUM> to improve visibility for both the pilot and copilot operating the aircraft.

A wiper blade for use on a windshield of an aircraft, the wiper blade comprising a support member coupled to a blade element, wherein the support member is constructed from a composite material; a wash tube extending through a central portion of the support member; and a plurality of nozzles spaced along a length of the support member, wherein the wash tube is fluidly coupled to the plurality of nozzles.

The wiper blade of the preceding paragraph can optionally include, additionally and/or alternatively, any one or more of the following features, configurations and/or additional components:.

The wash tube is an aperture that extends fully through the support member, from a first end of the support member to a second end of the support member.

The plurality of nozzles are apertures that extend from an outer surface of the support member to the wash tube within the central portion of the support member.

The support member is constructed from a plurality of composite plies stacked in a vertical direction from a base of the support member to a top of the support member.

The base of the support member is adjacent and contacting a portion of the blade element.

Each of the plurality of composite plies extends from a first end of the support member to a second end of the support member.

At least one of the plurality of composite plies comprises a cutout feature, and wherein a plurality of the cutout features of the at least one of the plurality of composite plies forms the wash tube within the central portion of the support member.

Each of the plurality of composite plies has a continuous, uninterrupted cross-section through a length and thickness of each individual ply.

The wash tube is produced by a drilling operation from a first end of the support member to a second end of the support member.

The plurality of nozzles are produced by a drilling operation from an outer surface of the support member to the wash tube within the central portion of the support member.

The support member is constructed from one or more of a carbon fiber reinforced polymer and a polytetrafluoroethylene (PTFE) composite material, and wherein the blade element is constructed from a nitrile rubber.

A plug positioned at each distal end of the wash tube.

An outer diameter of each plug is smaller than a diameter of the wash tube, and wherein the plugs are inserted into both distal ends of the wash tube.

Each of the plugs are constructed from the same material as the support member.

A fluid input extending into the support member and fluidly connecting to the wash tube within the support member, wherein the fluid input is an aperture that is positioned at approximately a center of the support member with respect to a length of the support member.

An input port axially aligned with and coupled to the fluid input of the support member, wherein the input port fluidly couples the fluid input of the support member to a fluid source.

A coupler coupled to and surrounding at least a portion of the support member and at least a portion of the blade element, wherein the input port extends through and is coupled to the coupler.

A fluid line is positioned between and fluidly couples the input port to the fluid source.

A fluid flows from the fluid source through the fluid line to the input port; the fluid flows through the input port into the fluid input; the fluid flows through the fluid input into the wash tube; and the fluid flows through the wash tube and dispenses through the plurality of nozzles onto the windshield of the aircraft.

The wiper blade comprises a plurality of clips, and wherein each of the plurality of clips are coupled to and surround at least a portion of the support member and at least a portion of the blade element.

While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof.

Claim 1:
A wiper blade (<NUM>) for use on a windshield of an aircraft, the wiper blade (<NUM>) comprising:
a support member (<NUM>) coupled to a blade element,
a wash tube (<NUM>) extending through a central portion of the support member (<NUM>); and
a plurality of nozzles (<NUM>) spaced along a length of the support member (<NUM>), wherein the wash tube (<NUM>) is fluidly coupled to the plurality of nozzles (<NUM>); and characterized in that the support member (<NUM>) is constructed from a composite material; and the wiper blade further comprising a plurality of clips (<NUM>), wherein each of the plurality of clips (<NUM>) are coupled to and surround at least a portion of the support member (<NUM>) and at least a portion of a blade element (<NUM>); and
a fastener (<NUM>) extending through each of the plurality of clips (<NUM>), wherein the fastener (<NUM>) is configured to extend only through each of the plurality of clips (<NUM>) and a rectangular top portion of the blade element (<NUM>) to secure each of the plurality of clips (<NUM>) to the blade element (<NUM>) together in compression.