Patent Description:
Cargo handling systems for aircraft typically include various tracks and rollers disposed on a cargo deck that spans the length of a cargo compartment. Cargo may be loaded from an entrance of the aircraft and transported by the cargo system to forward or aft locations, depending upon the configuration of the aircraft. Cargo handling systems, such as, for example, those used on aircraft for transport of heavy containerized cargo or pallets, also referred to herein as unit load devices (ULDs), typically include restraints to lock the ULDs in the cargo compartment. Typical latches for ULDs are operated manually, which lend themselves to potential user error. <CIT> relates to a cargo restraint sensor system, wherein sensors are configured to sense information relating to cargo latches, wireless communication circuits are configured to transmit the sensed information to a central controller, and batteries are powering the wireless communication circuits.

A latch assembly is provided in claim <NUM>.

In various embodiments, the pawl assembly comprises an inner pawl and an outer pawl. The inner pawl may be configured to activate the transducer in response to the pawl assembly reaching the restrained state. The transducer may comprise a piezoelectric button. The transducer may comprise an electric generator configured to convert one of linear or rotary motion into the electrical energy. The communications module may include a transmitter, the transmitter configured to transmit a wireless signal including a unique identifier of the latch assembly.

With reference to <FIG> and <FIG>, a schematic view of an aircraft <NUM> having a cargo deck <NUM> located within a cargo compartment <NUM> is illustrated, in accordance with various embodiments. The aircraft <NUM> may comprise a cargo load door <NUM> located, for example, at a forward end of the aircraft <NUM> and configured to rotate upward (as illustrated in <FIG>) or sideways to expose an opening <NUM> that provides access to the cargo compartment <NUM>. In various embodiments, a second cargo load door <NUM> may be located at other portions of the aircraft <NUM>, such as, for example, at an aft end of the aircraft <NUM> and configured to rotate downward (as illustrated in <FIG>) and provide a second opening <NUM> to gain access to the cargo compartment <NUM>. Inside the cargo compartment <NUM>, one or more trays <NUM>, e.g., a first tray or track <NUM> and a second tray or track <NUM>, extend generally from the fore end of the aircraft <NUM> to the aft end of the aircraft <NUM>. As described more fully below, the one or more trays <NUM> provide a support structure for which a platform <NUM> may transit along a length of the aircraft <NUM> between the fore end and the aft end and carry a ULD or some other form of cargo carrier, such as, for example, a container of a size typically used for ocean-going transport by ship or truck. Without loss of generality, a cargo load <NUM> of any size or shape, which may include objects within containers or ULDs or objects not within containers or ULDs, such as, for example, automobiles or the like, will be considered herein as configured for transport on the platform <NUM>.

Still referring to <FIG> and <FIG>, in various embodiments, the one or more trays <NUM>, during loading or unloading of the cargo load <NUM>, may be connected to a loading structure <NUM> which, in various embodiments, may comprise one or more trays or tracks <NUM> that correspond to the one or more trays <NUM> extending along the cargo deck <NUM> of the aircraft <NUM>. In various embodiments, the loading structure <NUM> may be attached to an elevated structure, such as, for example, a truck <NUM> (as illustrated in <FIG>) or a scissor lift or a loading dock or the like, such that the one or more trays <NUM> and the loading structure <NUM> are located substantially at the same elevation and configured to transition a platform <NUM> either onto or off from the one or more trays <NUM>. For example, a first cargo load <NUM> may be transitioned from the loading structure <NUM>, through the opening <NUM> and onto the one or more trays <NUM>, and then along the one or more trays <NUM> to the aft end of the aircraft, where the first cargo load <NUM> is secured for transport. This may be followed by a second cargo load <NUM>, a third cargo load <NUM> and so on until the cargo deck <NUM> is filled to a desired capacity with cargo. After the aircraft <NUM> has reached its destination, each cargo load, such as, for example, the first cargo load <NUM>, the second cargo load <NUM> and the third cargo load <NUM> are unloaded from the aircraft <NUM> in similar fashion, but in a reverse sequence to the loading procedure. To ensure cargo loads are restrained, the aircraft <NUM> may include a restraint assembly as described herein and in accordance with various embodiments.

Referring now to <FIG>, a portion of a cargo handling system <NUM> is illustrated, in accordance with various embodiments. The cargo handling system <NUM> is illustrated with reference to an XYZ coordinate system, with the X-direction extending longitudinally in an aft direction (and defining a longitudinal direction), the Y-direction extending perpendicular to the X-direction (and defining a lateral direction) and the Z-direction extending vertically, each direction being with respect to an aircraft in which the cargo handling system <NUM> is positioned, such as, for example, the aircraft <NUM> described above with reference to <FIG> and <FIG>.

In various embodiments, the cargo handling system <NUM> may define at least one tray or track <NUM> extending longitudinally in the aft direction (i.e., the X-direction). The tray <NUM> may include a plurality of rollers <NUM>, each roller extending laterally from a first lateral side of the tray <NUM> to a second lateral side of the tray <NUM>. In various embodiments, the cargo handling system <NUM> includes a platform <NUM> (or a plurality of platforms), such as, for example, the platform <NUM> described above with reference to <FIG> and <FIG>. The platform <NUM> is configured to support a cargo load <NUM>, which may include containerized or non-containerized cargo. As illustrated in <FIG>, in various embodiments, the tray <NUM> may include a substantially level surface throughout the length of the aircraft, though a portion of the tray <NUM> may be curved upward, particularly toward the aft end of the aircraft where the fuselage tends to curve upward at its base in order to facilitate takeoff and landing. The cargo handling system <NUM> may further comprise a latch assembly <NUM> and a cargo control unit <NUM>. The cargo control unit <NUM> may be in electrical communication with the latch assembly <NUM>. The latch assembly <NUM> may be configured to lock the platform <NUM> in place. For example, the control unit <NUM> may be configured to transition the latch assembly <NUM> from a locked position to an unlocked position, or vice versa.

Referring now to <FIG>, a perspective view of a latch assembly <NUM> installed within a tray <NUM> in a retracted or unlatched state (<FIG>) and a restrained or latching state (<FIG>), in accordance with various embodiments. The latch assembly <NUM> comprises a pawl assembly <NUM> operably coupled to a latch housing <NUM>. The latch housing <NUM> of the latch assembly <NUM> may be coupled to the tray <NUM> at a first longitudinal end <NUM> of the tray <NUM> and a second longitudinal end <NUM> of the tray <NUM>. As illustrated, the pawl assembly <NUM> is configured to transition from the un-restrained state (<FIG>) to the restrained state (<FIG>) during a loading process and vice versa during an unloading process. The restrained state (<FIG>) is utilized during transport of cargo (e.g., a cargo load <NUM> from <FIG> and <FIG>) to restrain a platform (e.g., platform <NUM> from <FIG>) or the like. In this regard, ensuring that each latch assembly <NUM> of a cargo handling system <NUM> from <FIG> is fully deployed in a restrained state and securing a respective platform is done during or after loading a cargo deck. Typical latch status detection systems are manual inspections, which may be time consuming and may be subject to inspector error. Thus, the latch assembly <NUM> further comprises a latch state detection system <NUM>. The latch state detection system <NUM> is configured to automatically detect when a latch assembly <NUM> is in a restrained state (<FIG>). The latch state detection system <NUM> of the latch assembly <NUM> is further configured to transmit, in response to being activated, a signal to indicate the latch assembly <NUM> is in a fully restrained state (<FIG>).

In various embodiments, the pawl assembly <NUM> comprises an outer pawl or latch <NUM> and an inner pawl or latch <NUM>. The inner pawl <NUM> is configured to restrain a first platform (e.g., platform <NUM>) and the outer pawl <NUM> is configured to restrain a second platform (e.g., an adjacent platform in accordance with platform <NUM>) during transport of cargo (e.g., cargo load <NUM> from <FIG> and <FIG>). During loading, the pawl assembly <NUM> transitions from the un-restrained state to the restrained state once a first platform is in place. In this regard, during loading one of the outer pawl <NUM> or the inner pawl <NUM> will engage the first platform and the remaining pawl will remain unengaged until a second platform is loaded and abuts the remaining pawl in accordance with various embodiments. Thus, during loading, the latch state is often detected one row at a time, in accordance with various embodiments.

Referring now to <FIG>, a cross-sectional view of a latch assembly <NUM> with the latch state detection system <NUM> is illustrated transitioning from an un-restrained state (<FIG>) to a restrained state (<FIG>), in accordance with various embodiments. The latch state detection system <NUM> is configured to generate an electrical signal in response to mechanical motion as described further herein. The latch state detection system <NUM> is further configured to transmit a latch identifier (i.e., a unique identifier in accordance with the Institute of Electrical and Electronics Engineers (IEEE) <NUM>. <NUM> or <NUM>. <NUM>, or the like) to a control unit of a cargo handling system (e.g., control unit <NUM> from <FIG>). The latch identifier transmitted to the control unit provides an indication to the control unit that the latch assembly <NUM> that is associated with the respective unique identifier is in a fully restrained state (i.e., an acceptable state for transport).

In various embodiments, the latch state detection system <NUM> comprises a transducer <NUM> and a communications module <NUM>. The transducer <NUM> is configured to convert mechanical energy to electrical energy. In various embodiments, the transducer <NUM> is a piezoelectric button <NUM>. In this regard, in response to being compressed (e.g., by a notch <NUM> of inner pawl <NUM>), the transducer <NUM> generates an electrical charge. In various embodiments, use of the inner pawl <NUM> as an activating device of the latch state detection system <NUM> may provide a better indication of the pawl assembly <NUM> being in a fully restrained state (<FIG>), as the outer pawl <NUM> may be in a fully restrained state without the inner pawl <NUM> being in a fully restrained state. In this regard, movement of the outer pawl <NUM> may drive movement of the inner pawl <NUM>, in accordance with various embodiments. Thus, a "fully restrained state" of the pawl assembly <NUM>, as described herein, refers to both the outer pawl <NUM> and the inner pawl <NUM> being fully deployed and in a position to engage / restrain a platform <NUM> or the like. The "fully restrained state" is illustrated in <FIG>.

The communications module <NUM> is configured to receive the electrical charge generated from the transducer <NUM> (e.g., via a conductive wire or the like). In response to receiving the electrical charge, the communications module <NUM> is powered and configured to transmit a signal to a control unit (e.g., control unit <NUM>) of a cargo handling system (e.g., cargo handling system <NUM> of <FIG>) as described previously herein.

In various embodiments, the transducer <NUM> may be oriented in a vertical direction (i.e., the Z-direction). However, the present disclosure is not limited in this regard. For example, as illustrated in <FIG>, the transducer <NUM> of the latch state detection system <NUM> may be oriented in a horizontal direction (e.g., the Y-direction) and still be within the scope of this disclosure. In various embodiments, by orienting the transducer <NUM> horizontally as shown in <FIG>, the latch state detection system <NUM> of <FIG> may provide an additional advantage from the latch state detection system <NUM> in that the notch <NUM> of the inner pawl <NUM> cannot be pushed back on from the transducer <NUM> to transition the pawl assembly <NUM> to a state that is less than fully deployed in the horizontal configuration (<FIG>) relative to the vertical configuration (<FIG>).

Referring now to <FIG>, a perspective view of a latch assembly <NUM> having a latch state detection system <NUM> is illustrated, in accordance with various embodiments. The latch assembly <NUM> comprises a transducer <NUM>. The transducer <NUM> is configured to convert mechanical energy to electrical energy in a similar manner to transducer <NUM>. However, the transducer <NUM> is configured to convert rotary motion to electrical energy as described further herein.

In various embodiments, the latch state detection system <NUM> further comprises a ratchet <NUM> including a gear <NUM> and a pawl <NUM>, a shaft <NUM>, a torsion spring <NUM>, and a link <NUM>. The gear <NUM> is coupled to the shaft <NUM> of the latch state detection system <NUM> and configured to rotate with the shaft <NUM>. Similarly, the link <NUM> is coupled to the shaft <NUM> and configured to rotate with the shaft <NUM> about a shaft axis in response to transitioning from an un-restrained state to a restrained state or vice versa as described further herein. In this regard, the link <NUM> is coupled to the shaft <NUM> at a proximal end of the link <NUM> and the link is coupled to a flange <NUM> of the inner pawl <NUM> at a distal end of the link <NUM>.

Referring now to <FIG>, <FIG> cross-sectional views of a latch assembly <NUM> with a latch state detection system <NUM> with a pawl assembly <NUM> in an un-restrained state (<FIG>, <FIG>) and a fully restrained state (<FIG>, <FIG>) are illustrated, in accordance with various embodiments. The inner pawl <NUM> is coupled to an inner pawl shaft <NUM> and configured to rotate with the inner pawl shaft <NUM> about an axis defined by the inner pawl shaft <NUM>. In response to the inner pawl <NUM> rotating in a first direction (e.g., counterclockwise) about the inner pawl axis, the link <NUM> causes the shaft <NUM> to rotate in an opposite direction (e.g., clockwise) about the link axis as shown in <FIG>.

In response to the shaft <NUM> rotating, the torsion spring <NUM> from <FIG> is loaded until a notch <NUM> of the inner pawl <NUM> contacts and rotates that pawl <NUM> of the ratchet <NUM>, which releases gear <NUM> from the pawl <NUM> (as shown in <FIG>). In response to being released, the shaft <NUM> rotates back due to the torsion spring <NUM> being loaded. In various embodiments, the transducer <NUM> from <FIG> is an electric generator configured to convert the rotary motion of the shaft <NUM> upon release of the gear <NUM> from the pawl <NUM> to electrical energy to power a communications module <NUM> of the latch state detection system <NUM>. In various embodiments, the latch state detection system <NUM> is configured such that the pawl <NUM> is not released until the pawl assembly <NUM> is in a fully deployed position (<FIG>). In various embodiments, the latch state detection system <NUM> may provide a design that can customize torque/speed of rotation for the pawl assembly <NUM> to optimize for energy conversion through a geartrain.

Although latch state detection system <NUM> is illustrated as loading a torsion spring via rotary motion and converting the rotary motion to electrical energy upon release, the latch state detection system <NUM> is not limited in this regard. For example, one skilled in the art may recognize that a similar concept to the latch state detection system <NUM> could be utilized replacing the torsion spring <NUM> with a tension or compression spring, loading the tension or compression spring by actuation of a bar which compress or extends the spring, and releasing the tension or compression spring via the notch <NUM> in accordance with various embodiments. In this regard, the same concept as the latch state detection system <NUM> applies and is illustrated in <FIG>. The latch state detection system would be configured to load a spring (e.g., torsional, compression, or tension) through mechanical motion (step <NUM>), release the spring in response to a pawl assembly reaching a fully restrained state (e.g., via a notch of an inner pawl) (step <NUM>), and converting a responsive mechanical motion created by the spring (e.g., a responsive rotation or a responsive translation) to electrical energy (e.g., via a transducer) (step <NUM>).

Referring now to <FIG>, a schematic view of control system <NUM> having a latch state detection system <NUM> is illustrated in accordance with various embodiments. All of the latch state detection systems disclosed herein are in accordance with latch state detection system <NUM>. In this regard, as previously described herein, each latch state detection system (e.g., latch state detection systems <NUM>, <NUM>, <NUM>) include a transducer <NUM> (e.g., transducer <NUM>, <NUM>) and a transmitter <NUM> (e.g., a transmitter disposed in communications module <NUM>).

In various embodiments, the control system <NUM> comprises a master controller <NUM> in operable communication (e.g., wireless) with the latch state detection system <NUM> of a latch assembly (e.g., latch assembly <NUM>, <NUM>, or the like). In various embodiments, controller <NUM> may be integrated into a computer system, such as cargo control unit <NUM> from <FIG>. In various embodiments, controller <NUM> may be configured as a central network element or hub to access various systems and components of control system <NUM>. Controller <NUM> may comprise a network, computer-based system, and/or software components configured to provide an access point to various systems and components of control system <NUM>. In various embodiments, controller <NUM> may comprise a processor. In various embodiments, controller <NUM> may be implemented in a single processor. In various embodiments, controller <NUM> may be implemented as and may include one or more processors and/or one or more tangible, non-transitory memories and be capable of implementing logic. Each processor can be a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. Controller <NUM> may comprise a processor configured to implement various logical operations in response to execution of instructions, for example, instructions stored on a non-transitory, tangible, computer-readable medium configured to communicate with controller <NUM>.

System program instructions and/or controller instructions may be loaded onto a non-transitory, tangible computer-readable medium having instructions stored thereon that, in response to execution by a controller, cause the controller to perform various operations. The term "non-transitory" is to be understood to remove only propagating transitory signals per se from the claim scope and does not relinquish rights to all standard computer-readable media that are not only propagating transitory signals per se.

In various embodiments, controller <NUM> may be in wireless communication with the latch state detection system <NUM>. For example, controller <NUM> may be in electronic communication with a receiver <NUM> of the control system <NUM>. Although illustrated as comprising a receiver <NUM>, the present disclosure is not limited in this regard. For example, the receiver <NUM> may be a transceiver in accordance with various embodiments. In various embodiments, the controller <NUM> may also be in electronic communication with a display device <NUM>. In this regard, in response to receiving an indication from the latch detection system that a respective latch assembly is in a fully restrained state, the display device <NUM> may be commanded to, via the controller, indicate the respective latch assembly is in an acceptable state for transport, in accordance with various embodiments.

Claim 1:
A latch assembly (<NUM>), comprising:
a housing (<NUM>);
a pawl assembly (<NUM>) coupled to the housing (<NUM>), the pawl assembly configured to transition from an un-restrained state to a restrained state; and
a latch state detection system (<NUM>) comprising a transducer (<NUM>) and a communications module (<NUM>), the transducer configured to convert mechanical energy from the pawl assembly (<NUM>) reaching the restrained state to an electrical energy configured to power the communications module (<NUM>), wherein, in response to receiving the electrical energy, the communications module (<NUM>) is powered and configured to transmit a signal to a control unit of a cargo handling system.