WO2002006594A1

WO2002006594A1 - Vacuum toilet system for vehicles

Info

Publication number: WO2002006594A1
Application number: PCT/FI2001/000608
Authority: WO
Inventors: Ian Tinkler; Doug Wallace; Mark Pondelick
Original assignee: Evac International Oy
Priority date: 2000-07-17
Filing date: 2001-06-26
Publication date: 2002-01-24
Also published as: AU2001272592A1

Abstract

A vacuum toilet system (10) for use on a vehicle is disclosed. The vehicle includes an integrated logic device electronically coupled to an electronics system bus (16). A collection tank (38) is provided connected to a vacuum generator (56) for creating a partial vacuum in the tank. A toilet (18f,18a) is provided having an outlet (22) fluidly communicating through a flush control valve (34) with the collection tank (38). A rinse nozzle (24) is disposed in a bowl (20) of the toilet (18f,18a) and is connected through a rinse valve (30) to a rinse fluid supply (28). A flush button (37) is positioned near the toilet for initiating a flush command. The flush button, rinse valve, flush control valve, and vacuum generator are operably coupled to the integrated logic device for operating the components. The integrated logic device may further include an alarm circuit operatively coupled to the components for generating maintenance and toilet inoperative alarms.

Description

VACUUM TOILET SYSTEM FOR VEHICLES

FIELD OF THE INVENTION

The present invention generally relates to toilets and, more particularly, to vacuum toilets for use on vehicles, i.e. vacuum toilet systems according to the preamble of claim 1 , claim 1 0, claim 1 9, and claim 24.

BACKGROUND OF THE INVENTION

Vacuum toilets for use on vehicles are generally known in the art. Vacuum toilets used on an aircraft, for example, typically include a collection tank connected to a vacuum generator for creating partial vacuum in the tank. One or more toilets are connected to the collection tank and a flush valve is disposed between each toilet and the collection tank for controlling fluid communication there between. A spray ring is attached to a bowl of the toilet and is connected to a rinse fluid supply. A rinse valve is disposed between the spray ring and the rinse fluid supply to selectively discharge rinse fluid from the spray ring. A flush button is provided near each toilet for initiating a flush cycle during which the flush and rinse valves are temporarily opened. While the flush valve is open, waste material and fluid present in the toilet is transferred to the collection tank by a pressure differential created by the partial vacuum in the tank.

A flush control unit (FCU) is typically used to receive the flush command and actuate the flush and rinse valves during a flush cycle. The FCU receives the flush signal from the flush button and delivers a current, typically 28 vdc, to the rinse and flush valves to open and close the valves. The FCU further includes logic circuits for timing when to open and close the valves. The valves further include sensors for indicating the position of the valve and providing feedback to the FCU. According to the feedback, the FCU may generate error signals when, for example, a valve fails to open or close in response to a command. The actuation and feedback functions of the FCU require the FCU to be connected to a power supply. On an aircraft, for example, a central on-board power source is typically provided, and the FCU is connected via wires to the power source. Each toilet requires an FCU, and therefore wires must be run from each FCU to the power source, thereby requiring labor and increasing the weight of the toilet apparatus due to the FCU and wiring.

Conventional vacuum toilet systems also include a logic control module (LCM) for cutting off power to the toilets under certain conditions, such as when the collection tank is full. The LCM is typically connected between the FCU and power supply, and includes a logic circuit. One or more level sensors provided in the tank are also connected to the LCM to provide feedback to the logic circuit. When the sensors indicate that the tank is full, the LCM disables all of the toilets in the system so that the tank does not overflow. In addition, the LCM executes built-in- tests ("BITs") to ensure that the sensors are functioning properly. During a typical BIT, the LCM sends a "tank full" input to the sensor and the feedback from the sensor is monitored. If the sensor returns a "tank full" signal, the sensor is found to be functional. If, however, the sensor does not return a "tank full" signal, a sensor malfunction alarm is generated. Thus, the sensors and each toilet in the system FCU must be connected to the LCM.

Vacuum toilet systems further use the FCU or LCM to control operation of the vacuum generator. On most aircraft, for example, a vacuum blower is used as the vacuum generator, and operation of the vacuum blower is initiated by the FCU. Once a flush command is received, the FCU operates the vacuum blower for a set period of time (e.g., 1 5 seconds), to generate vacuum on demand. Such systems, therefore, require the FCU to be connected to the vacuum blower.

Other vacuum toilet systems, such as trapped vacuum systems, use a vacuum pump controlled by the LCM to maintain a relatively constant vacuum level in the collection tank. These systems typically have a vacuum switch, which monitors a vacuum level in the collection tank and actuates between open and closed positions according to the vacuum level. When the vacuum level is adequate, the switch opens and a relay cuts off power to the vacuum pump. When the vacuum level is too low, the switch closes and the relay energizes the vacuum pump. Accordingly, these systems require the switch to be connected to a relay and wired to the LCM and vacuum pump.

On aircraft, the vacuum switch is further provided for disabling the vacuum generator at high altitudes. At altitudes above approximately 4900 m (approximately 1 6,000 feet), the ambient pressure is sufficiently low compared to the pressurized aircraft cabin to create the required pressure differential. When the pressure is sufficiently low, the vacuum switch signals the LCM or FCU, depending on the type of vacuum toilet system, to disable the vacuum generator. Thus, conventional vacuum toilet systems require additional space for the LCM and must be wired to the power source, further increasing labor and weight of the system.

Vehicles such as aircraft have recently been provided with two or more power and control devices, such as devices marketed by Hamilton Sundstrand Co. As "Secondary Power Distribution Assemblies" (SPDAs). One or more SPDAs are typically located along the cabin of an aircraft to provide local connections for hook-up to various aircraft subsystems. The SPDAs are connected to an avionics system bus which, in turn, may communicate with a status panel and maintenance computer. The status panel provides feedback regarding the operation of the subsystems, while the maintenance computer logs alarms and generates maintenance reminders.

In view of the foregoing, a vacuum toilet system for use on aircraft is needed which has a lower weight and reduces labor required for installation. SUMMARY OF THE INVENTION

In accordance with certain aspects of the present invention, a vacuum toilet system is provided for use on a vehicle having a universal controller adapted to control multiple vehicle auxiliary sub-systems according to claim 1 . The vacuum toilet system comprises a toilet having an outlet, a collection tank in fluid communication with the toilet outlet, and a vacuum generator in fluid communication with the collection tank, the vacuum generator operable to produce a partial vacuum in the collection tank. A flush valve is disposed between the toilet outlet and the collection tank and is operable to control fluid communication between the collection tank and the toilet outlet. A rinse fluid nozzle is associated with the toilet and adapted for connection to the rinse fluid source. A rinse fluid valve is disposed between the rinse fluid nozzle and the rinse fluid source, and is operable to control fluid communication between the rinse fluid source and the rinse fluid nozzle. A flush actuator is associated with the flush valve and rinse fluid valve, and is operable to generate a flush command. At least one of the flush actuator, flush valve, rinse fluid valve, and vacuum generator is connected to the universal controller.

In accordance with other aspects of the present invention, a vacuum toilet system is provided for use with a rinse fluid source according to claim 1 0. The vacuum toilet system comprises a toilet having an outlet, a collection tank in fluid communication with the toilet outlet, and a vacuum generator in fluid communication with the collection tank, the vacuum generator operable to produce a partial vacuum in the collection tank. A flush valve is disposed between the toilet outlet and the collection tank, the flush valve operable to control fluid communication between the collection tank and the toilet outlet. A rinse fluid nozzle is associated with the toilet and adapted for connection to the rinse fluid source, and a rinse fluid valve is disposed between the rinse fluid nozzle and the rinse fluid source, the rinse fluid valve operable to control fluid communication between the rinse fluid source and the rinse fluid nozzle. A flush actuator is associated with the flush valve and rinse fluid valve, the flush actuator operable to generate a flush command. A universal controller is connected to the flush actuator and controls at least two of the flush valve, rinse fluid valve, and vacuum generator in response to the flush command.

In accordance with additional aspects of the present invention, a vacuum toilet system is provided for use with a rinse fluid source according to claim 1 9. The vacuum toilet system comprises a toilet having an outlet, a collection tank in fluid communication with the toilet outlet, and a vacuum generator in fluid communication with the collection tank, the vacuum generator operable to produce a partial vacuum in the collection tank. A flush valve is disposed between the toilet outlet and the collection tank and is operable to control fluid communication between the collection tank and the toilet outlet. A rinse fluid valve is disposed between the rinse fluid source and the toilet operable to establish fluid communication between the rinse fluid source and toilet, thereby delivering rinse fluid, and a flush actuator is associated with the flush valve and rinse fluid valve, the flush actuator operable to generate a flush command. A universal controller and power distribution module is adapted for connection to at least one of the flush valve, flush actuator, rinse fluid valve, and vacuum generator.

In accordance with still further aspects of the present invention, a vacuum toilet system is provided for use with a rinse fluid source according to claim 24. The vacuum toilet system comprises a collection tank and a vacuum generator in fluid communication with the collection tank, the vacuum generator operable to produce a partial vacuum in the collection tank. A first toilet is provided having a first outlet in fluid communication with the collection tank, a first flush valve disposed between the first toilet outlet and the collection tank operable to control fluid communication between the collection tank and first toilet outlet, a first rinse fluid valve disposed between the rinse fluid source and the toi- let operable to establish fluid communication between the rinse fluid source and the first toilet, thereby delivering rinse fluid to the first toilet, and a first flush actuator associated with the first flush valve and first rinse fluid valve operable to generate a first toilet flush command. A second toilet is provided having a second outlet in fluid communication with the collection tank, a second flush valve disposed between the second toilet outlet and the collection tank operable to control fluid communication between the collection tank and second toilet outlet, a second rinse fluid valve disposed between the rinse fluid source and the second toilet operable to establish fluid communication between the rinse fluid source and the second toilet, thereby delivering rinse fluid to the second toilet, and a second flush actuator associated with the second flush valve and second rinse fluid valve operable to generate a second toilet flush command. A universal controller is connected to and controls at least one of the first flush valve, first rinse fluid valve, and first flush actuator, and at least one of the second flush valve, second rinse fluid valve, and second flush actuator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic drawing illustrating one embodiment of a toilet system in accordance with the teachings of the present invention.

FIG. 2 is a block diagram illustrating the main components of the toilet system illustrated in FIG. 1 .

FIG. 3 is block diagram illustrating a universal controller for use in the vacuum toilet system.

FIG. 4 is a block diagram illustrating a toilet system in which a universal controller is connected to two toilets.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings, FIG. 1 illustrates a vacuum toilet system 1 0 for use on an aircraft. The aircraft includes a status panel 1 2 and a maintenance computer 1 4 for storing and displaying information re- garding the various subsystems of the aircraft. The aircraft subsystems are connected to the status panel 1 2 and maintenance computer 1 4 by an avionics system bus 1 6.

The vacuum toilet system 10 includes a pair of toilets 1 8f, 1 8a, for receiving waste. Each toilet 1 8f, 1 8a has a bowl 20, which defines a toilet outlet 22. A rinse fluid dispenser, such as spray ring 24, is positioned inside the bowl 20 of each toilet 1 8f, 1 8a and is connected by a rinse fluid pipe 26 to a rinse fluid supply 28. A rinse valve 30 is disposed in each rinse fluid pipe 26 and is moveable between open and closed positions, thereby to selectively control the supply of rinse fluid to the associated spray ring 24.

A discharge pipe 32 is attached to the outlet 22 of each toilet 1 8f , 1 8a, and each discharge pipe 32 has a flush valve 34 disposed therein. In the illustrated embodiment, the discharge pipes 32 converge to form a common pipe 36. A flush button 37 is positioned near each toilet 1 8f, 1 8a and is adapted to provide a flush signal in response to actuation by a user.

A collection tank 38 is provided for receiving waste transported from the toilets 1 8f, 1 8a. The collection tank includes a waste intake port 40, which is connected to the common pipe 36. An air/water separator 42 is provided at a vacuum port 44 of the tank 38, and a drain port 46 is provided near a bottom of the tank 38 and is connected to a drain pipe 48. A drain valve 50 is disposed in the drain pipe 48 and has an outlet 52 located in a service panel 54 of the aircraft. A service door switch 55 is provided in the service panel for indicating the position of the service door.

A vacuum generator 56 is provided for creating a partial vacuum in the collection tank 38. As illustrated in FIG. 1 , the vacuum generator 56 is connected by a vacuum pipe 58 to the vacuum port 44 of the collection tank 38. A bypass branch 60 having a check valve 62 is provided in the vacuum pipe 58 which allows ambient pressure to create the partial vacuum in the collection tank 38 when the aircraft is at altitudes greater than approximately 4900 m (approximately 1 6,000 feet). The vacuum generator 56 may be provided as a vacuum pump, a vacuum blower, an air ejector, or any other type of device capable of creating a partial vacuum in the collection tank 38. The vacuum generator 56 is disabled when the service door switch 55 indicates that the service door is open.

According to the illustrated embodiment, a vacuum switch 64 is provided for providing feedback regarding the vacuum level in the collection tank 38. In the illustrated embodiment, the vacuum switch 64 is disposed in fluid communication with the vacuum pipe 58 at a point between the vacuum generator 56 and the collection tank 38. The vacuum switch 64 is responsive to a pressure level in the vacuum pipe 58 to actuate between open and closed positions. In operation, when the actual vacuum level in the vacuum pipe 58 reaches a desired vacuum level, the vacuum switch 64 moves to the open position. When the actual vacuum level in the vacuum pipe 58 drops below the desired vacuum level, the vacuum switch 64 automatically actuates to the closed position. The vacuum generator 56 is controlled according to the position of the vacuum switch 64, so that the vacuum generator 56 turns on when the switch 64 is in the closed position, and turns off when the switch 64 is in the open position, as described in greater detail below.

It will be appreciated that the vacuum switch 64 moves to the open position when the pressure of the ambient air outside the aircraft is sufficiently lower than the aircraft cabin pressure to transport waste. In the illustrated embodiment, the check valve 62 will open when ambient pressure is lower than pressure inside the vacuum pipe 58, thereby placing the vacuum pipe 58 and collection tank 38 at ambient pressure. When the vacuum switch 64 senses the reduced ambient pressure, it moves to the open position. The vacuum switch 64 is preferably a normally closed switch which opens when the vacuum level in the col- lection tank 38 has reached a high vacuum level (e.g., 13 inches Hg [about 0.45 bar]) and closes when the pressure level drops below a low vacuum level (e.g. , 10 inches Hg [about 0.35 bar]).

The vacuum toilet system 1 0 described and illustrated herein is a trapped-vacuum type system, in which the collection tank is continuously held under partial vacuum. However, other types of systems, such as vacuum-on-demand, may be used in accordance with the present invention. Vacuum-on-demand systems often use a vacuum blower as the vacuum generator for quickly establishing partial vacuum in the collection tank in response to a flush command. After the flush valve closes, however, the vacuum blower switches off. In such a system, the vacuum switch is used to disable the vacuum blower once the aircraft is above a certain altitude, but is not used to maintain a constant vacuum level in the tank as described above in connection with the illustrated embodiment.

A pair of level sensors 66 is provided with the collection tank 38 for indicating when the collection tank 38 is filled to its usable capacity. In the preferred embodiment, each sensor 66 is an ultrasonic level sensor, which is tuned to respond only when liquid is present at a predetermined distance from the sensor, known as a sensing gap. The sensors 66 preferably have a low current output when liquid is not present in the sensing gap, and a high current output when liquid is present in the gap, so that feedback from the sensors 66 may be quickly and accurately interpreted. While the preferred embodiment uses ultrasonic sensors, it will be appreciated that other types of sensors, such as load cell and capacitance sensors, may be used in accordance with the present invention. The use of two sensors 66 provides redundant sensing and positive confirmation of a full tank, which may be taken into account before disabling operation of the vacuum toilet system 1 0. While the present embodiment uses two sensors 66, a single sensor or more than two sensors may be used without the departing from the scope of the present invention. The collection tank 38 further includes a pair of tank rinse nozzles 68 for cleaning the surface of the tank during discharge. The tank rinse nozzle 68 are positioned near an upper wall of the collection tank 38 and oriented to direct rinse fluid toward the side walls of the tank 38. The tank rinse nozzles 68 are connected to a tank rinse supply pipe 70 having a tank rinse valve 72 for controlling flow of rinse fluid to the nozzles 68. The tank rinse supply pipe 70 has an inlet 74 located in the service panel 54 of the aircraft. The inlet 74 is adapted for connection to a supply of rinse fluid which is used during routine maintenance when the aircraft in on the ground. The tank rinse valve 72 is preferably interlocked with the drain valve 50 so that the rinse valve 72 opens only when the drain valve 50 is also open, thereby to avoid flooding the collection tank 38. In addition to receiving waste from the toilets 1 8f,

1 8a, additional waste fluid generating devices may also be connected to the collection tank 38. As illustrated in FIG. 1 , a pair of sinks 76 is provided which produce gray water. Each sink 76 has an outlet 78 attached to a drain pipe 80. The drain pipes 80 are connected to the common pipe 36, which leads to the collection tank 38. A gray water interface valve 82 is disposed in each drain pipe 80 for controlling the flow of gray water from the sink 76 to the collection tank 38. Because the vacuum toilet system 1 0 is continuously maintained under vacuum, pneumatic activators 84 may be used to actuate the interface valves 82 between open and closed positions. The pneumatic activators 84 sense the presence of waste fluid upstream of the valves 82 and use the vacuum present downstream of the valves to open the normally closed interface valves 82. Because the interface valves 82 are pneumatically actuated, they do not require connection to an electric power source.

According to the preferred embodiment, at least one universal controller is used for powering and controlling the toilet system 1 0. Contrary to conventional aircraft which typically have a single, centrally located power generator, the present aircraft has a forward universal con- troller 86f positioned near the front of the plane and an aft universal controller 86a positioned near a rear of the aircraft. In the preferred embodiment, each universal controller 86f, 86a is capable of sending and receiving control signals to and from the components of the toilet system 1 0. As best shown in FIG. 3, the aft universal controller 86a includes a flush control circuit 88 for controlling the flush valve 34, a rinse control circuit for controlling the rinse valve 30, and a vacuum generator control circuit 92 for controlling the vacuum generator 56. The control circuits are connected to an output interface 91 , which provides a connection for each component of the vacuum toilet system 1 0. A processor 93 having control software is connected to the circuits to direct operation of the circuits. The processor 93 is also connected to an input interface 89, which is electrically coupled to the avionics system bus 1 6 provided with the aircraft.

In the vacuum toilet system 10 having two toilets 18a, 1 8f , as illustrated in FIG. 1 , each universal controller 86a, 86f controls an associated toilet. For example, the forward universal controller 86f controls the forward toilet 1 8f, while the aft universal controller 86a controls the aft toilet 1 8a. More specifically, forward universal controller 86f is connected by lead wires to the rinse valve 30, flush valve 34, and flush button 37 associated with the forward toilet 1 8f , while the aft universal controller 86a is connected by lead wires to rinse valve 30, flush valve 34, and flush button 37 associated with the aft toilet 1 8a.

The universal controllers 86a, 86f may be connected to one or more components of the toilet system 1 0. For example, the universal controllers 86a, 86f may provide all of the control logic normally associated with the conventional flush control units (FCUs). Accordingly, as schematically illustrated in FIG. 3, the aft universal controller 86a includes a control circuit 88 for operating the flush valve for a given period of time in response to actuation of the flush button 37. Similarly, the aft univer- sal controller 86a includes a control circuit 90 for controlling the rinse valve 30 at the appropriate time during the flush cycle.

In a preferred method of operation, upon receipt of a request for flush from the flush button 37, the aft universal controller 86a actuates the flush valve 34 to the open position, closing an open contact switch (not shown). The flush valve remains open for a period of time, preferably one to four seconds. One tenth of a second after the flush valve 34 is opened, the rinse valve 30 is opened for 0.7 seconds. After the one second valve-open period, the aft universal controller 86a sends a signal to close the flush valve 34. The universal controller does not accept another request for flush for 1 5 seconds to prevent repetitive flushing and degradation of vacuum pressure in the waste system. If the flush valve is prevented from closing fully by an obstruction in the toilet discharge, the universal controller preferably delivers a reflush signal to the flush valve actuator. The reflush signal activates a reflush operation, which automatically attempts to clear the obstruction so that the toilet remains functional for the next user. During the reflush operation, the flush valve 34 preferably remains open for 4 seconds to allow the greatest chance of the obstruction clearing. During automatic reflushes, the rinse valve 30 is not activated to prevent the toilet from overfilling should the obstruction persist. Rinse operation is automatically restored for all subsequent flush requests. Preferably, the position of the rinse valve 30 is measured by a Hall effect sensor (not shown) monitored by the universal controller, however feedback from the rinse valve 30 is not necessary.

The time periods referred to above in connection with flush and reflush operations are given by way of example only and the present invention is not limited thereto. In fact, different time periods may be desirable for different applications. By incorporating the system logic into the universal controllers, valve sequencing and timing may be adjusted quickly and easily using avionics system software. In addition, or as an alternative, to controlling flush operations, the universal controllers 86 may control operation of the vacuum generator 56, and generate alarms which disable the toilets 1 8f, 1 8a, as was conventionally performed by multiple FCUs or LCMs. In the illustrated embodiment, the aft universal controller 86a is also connected by lead wires to the ultrasonic level sensors 66, vacuum switch 64, vacuum generator 56, and service door switch 55. In response to the feedback from these components, the aft universal controller 1 8a controls operation of the vacuum generator 56 and toilets 1 8f, 1 8a.

The aft universal controller 86a preferably includes a vacuum generator control circuit 92 for receiving feedback from the vacuum switch 64 (FIG. 3). The vacuum generator control circuit 92 controls operation of the vacuum generator 56 according to the feedback from the switch 64. When the vacuum switch 64 opens in response to an adequate vacuum level in the collection tank 38, the aft universal controller 86aa stops operation of the vacuum generator 56. Conversely, when the vacuum switch 64 closes due to inadequate vacuum level, the aft universal controller 1 8a starts the vacuum generator to increase the vacuum level in the tank 38.

In addition, the universal controllers 86a, 86f may be used to disable the vacuum toilet system 1 0 in an alarm situation and provide reports to the status panel 1 2 and maintenance computer 1 4. In the illustrated embodiment, the processor 93 of the aft universal controller 86a includes alarm software for processing feedback from the components. For example, feedback from the sensors 66 may be continuously monitored to determine when the collection tank 38 has reached capacity. When the fluid level inside the collection tank 38 reaches the sensing gap of the sensor 66, the aft universal controller 86a interrupts power from a power supply circuit 96 to the toilet components, thereby disabling the vacuum toilet system 1 0. The aft universal controller 86a also sends a "tank full" signal via the avionics system bus 1 6 to the status panel 1 2 and maintenance computer 14. In the preferred embodiment, the "tank full" signal is sent only when both sensors 66 indicate a full collection tank 38 for five seconds.

The alarm software associated with the processor 93 may also conduct built-in-tests (BITs) to ensure that the sensors 66 are operating properly. During a BIT, the aft universal controller 86a sends a "tank full" input to the sensor 66 and monitors the feedback generated by the sensors. If a "tank full" signal is received from each sensor, the sensors are functioning properly. If a sensor does not return a "tank full" signal, the alarm circuit 94 generates a sensor malfunction message, which is delivered to the aircraft maintenance computer 1 4 via the system bus 1 6. In the event of a sensor malfunction, the remaining sensor 66 may still be used to determine the full tank condition. If both sensors malfunction, the universal controller 86a may be programmed to send a "system inoperable" signal to the status panel 12 and a fault indication will be sent to the maintenance computer 14. The BITs are executed according to a set schedule, such as once an hour.

The alarm software may further generate alarms in response to feedback from the flush valve 34 and rinse valve 30. For example, if the open contact switch of the flush valve 34 does not close after an open valve command has been given, the alarm circuit 94 generates a signal to the status panel 1 2 showing an inoperable toilet and indicates a flush valve fault to the maintenance computer 14. In addition, if a flush valve obstruction remains after an automatic reflush, the universal controller generates a signal to the status panel 1 2 indicating an inoperable toilet and provides a flush valve open fault to the maintenance computer 1 4. Furthermore, if the rinse valve does not open or does not fully close as commanded, an alarm signal is sent to the status panel 1 2 indicating an inoperable toilet and a rinse valve fault message is forwarded to the maintenance computer 14. In a preferred embodiment, the universal controllers include a power supply 96 for powering the components of the toilet system 1 0. Because the universal controllers are located throughout the aircraft cabin and typically relatively near toilet locations, the wire runs needed for the toilet system 1 0 are substantially reduced.

It will be appreciated, however, that while the illustrated embodiment uses universal controllers 86f, 86a that provide both power and logic, the universal controllers may provide toilet system logic only, in accordance with the present invention. The universal controllers would include circuits for controlling certain subsystems of the vacuum toilet system 1 0, but would not include a power supply. Instead, the universal controllers would be connected to a separate power generator provided on the aircraft. The universal controllers having logic only would replace the LCM and various FCUs used in conventional systems, thereby facilitating installation and reducing the space requirements for the system.

Furthermore, while the embodiment illustrated in FIGs. 1 -3 uses universal controllers which incorporate all of the subsystems of the vacuum toilet system 1 0, it will be appreciated that only specific subsystems may be connected to the universal controllers while still providing the advantages and benefits described herein. For example, the aft universal controller 86a may only incorporate the flush and rinse control circuits 88, 90, while the vacuum generator control circuit 92 is separately powered and controlled.

In the alternative embodiment illustrated at FIG 4, a universal controller 1 50 is provided for controlling two toilets 1 52, 1 54. The first toilet 1 52 includes a flush actuator 1 56, a flush valve 1 58, and a rinse fluid valve 1 60. The second toilet 1 54 similarly has a flush actuator 1 62, a flush valve 1 64, and a rinse fluid valve 1 66. The universal controller may also be connected to the service door switch 55, the vacuum switch 64, the level sensors 66, and the vacuum generator 56. The universal controller 1 50 preferably includes the same processor and control circuits as shown in FIG. 3, and controls at least one component of each toilet 1 52, 1 54. In this embodiment, certain advantages of the present invention are magnified, since a single universal controller may be used to replace multiple FCUs or other individual component controllers. Furthermore, the universal controller provides a centralized location for power and logic, thereby simplifying installation and maintenance.

In view of the foregoing, it will be appreciated that a new and improved vacuum toilet system for use on aircraft is provided. The vacuum toilet system uses universal controllers to operate and control various components of the system, thereby eliminating the need for dedicated control boxes for each component. The use of the universal controllers not only reduces space requirements for the system, but also reduces weight and labor costs associated with the system.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom, as modifications would be obvious to those skilled in the art.

Claims

CLAIMS:

1 . A vacuum toilet system for use on a vehicle having a universal controller (86f) adapted to control multiple vehicle auxiliary sub-systems, characterised in that the vacuum toilet system comprises: a toilet (1 8f) having an outlet (22); a collection tank (38) in fluid communication with the toilet outlet (22); a vacuum generator (56) in fluid communication with the collection tank (38), the vacuum generator operable to produce a partial vacuum in the collection tank; a flush valve (34) disposed between the toilet outlet (22) and the collection tank (38), the flush valve operable to control fluid communication between the collection tank and the toilet outlet; a rinse fluid nozzle (24) associated with the toilet (1 8f) and adapted for connection to the rinse fluid source (28); a rinse fluid valve (30) disposed between the rinse fluid nozzle (24) and the rinse fluid source (28), the rinse fluid valve operable to control fluid communication between the rinse fluid source and the rinse fluid nozzle; and a flush actuator (37) associated with the flush valve (34) and rinse fluid valve (30), the flush actuator operable to generate a flush command; and in that at least one of the flush actuator (37), flush valve (34), rinse fluid valve (30), and vacuum generator (56) is connected to the universal controller (86f).

2. The vacuum toilet system of claim 1 , characterised in that the vehicle includes an electronics system bus (1 6) electronically connected to the universal controller (86f).

3. The vacuum toilet system of claim 2, characterised in that the vehicle further comprises a status panel ( 1 2) electronically connected to the electronics system bus (1 6), and in which the universal controller (86f) is adapted to generate and forward toilet inoperative signals to the status panel via the electronics system bus (1 6) in response to feedback from at least one of the flush actuator (37), flush valve (34), rinse fluid valve (30), and vacuum generator (56).

4. The vacuum toilet system of claim 2, characterised in that the vehicle further comprises a maintenance computer (1 4) electronically connected to the electronics system bus (1 6), and in which the universal controller (86f) is adapted to generate and forward maintenance messages to the maintenance computer (1 4) via the electronics system bus (1 6) in response to feedback from at least one of the flush actuator (37), flush valve (34), rinse fluid valve (30), and vacuum generator (56).

5. The vacuum toilet system of claim 1 , characterised in that the flush valve (34), rinse fluid valve (30), and flush actuator (37) are connected to the universal controller (86f), the universal controller operating the flush valve and rinse fluid valve in response to the flush command.

6. The vacuum toilet system of claim 5, characterised in that the system further comprises a sensor (66) associated with the collection tank (38) for detecting a high waste level and generating a tank full signal, the universal controller (86f) disabling the flush valve (34), rinse fluid valve (30), and flush actuator (37) in response to the tank full signal.

7. The vacuum toilet system of claim 1 , characterised in that the vacuum generator (56) is connected to the universal controller (86f), the vacuum toilet system further comprising a vacuum level sensor (64) associated with the collection tank (38) for generating a vacuum level signal coupled to the universal controller (86f), the universal controller operating the vacuum generator in response to the vacuum level signal.

8. The vacuum toilet system of claim 1 , characterised in that the universal controller (6f) further includes a power distribution module.

9. The vacuum toilet system of claim 1 , characterised in that the system further comprises a second toilet (1 8a) having an outlet (22) in fluid communication with the collection tank (38), a second flush valve (34) disposed between the second toilet outlet (22) and the collection tank (38), a second rinse fluid nozzle (24) associated with the second toilet (1 8a) and adapted for connection to the rinse fluid source (28), a second rinse fluid valve (30) disposed between the second rinse fluid nozzle (24) and the rinse fluid source (28), and a second flush actuator (37) coupled to the second flush valve (34) and second rinse fluid valve (30), wherein at least one of the second flush valve (34), second rinse fluid valve (30), and second flush actuator (37) is connected to a universal controller (86a).

1 0. A vacuum toilet system for use with a rinse fluid source (28), characterised in that the vacuum toilet system comprises: a toilet (1 8f) having an outlet (22); a collection tank (38) in fluid communication with the toilet outlet (22); a vacuum generator (56) in fluid communication with the collection tank (38), the vacuum generator operable to produce a partial vacuum in the collection tank; a flush valve (34) disposed between the toilet outlet (22) and the collection tank (38), the flush valve operable to control fluid communication between the collection tank and the toilet outlet; a rinse fluid nozzle (24) associated with the toilet ( 1 8f) and adapted for connection to the rinse fluid source (28); a rinse fluid valve (30) disposed between the rinse fluid nozzle (24) and the rinse fluid source (28), the rinse fluid valve operable to control fluid communication between the rinse fluid source and the rinse fluid nozzle; a flush actuator (37) associated with the flush valve (34) and rinse fluid valve (30), the flush actuator operable to generate a flush command; and a universal controller (86f) connected to the flush actuator (37) and controlling at least two of the flush valve (34), rinse fluid valve (30), and vacuum generator (56) in response to the flush command.

1 1 . The vacuum toilet system of claim 1 0, characterised in that the vacuum toilet system (1 0) is disposed in a vehicle having an electronics system bus (1 6), and in which the universal controller (86f) is connected to the electronics system bus.

1 2. The vacuum toilet system of claim 1 1 , characterised in that the vehicle further comprises a status panel (1 2) electronically connected to the electronics system bus (1 6), and in which the universal controller (86f) is adapted to generate and forward toilet inoperative signals to the status panel via the electronics system bus.

1 3. The vacuum toilet system of claim 1 1 , characterised in that the vehicle further comprises a maintenance computer (14) electronically connected to the electronics system bus (1 6), and in that the universal controller (86f) is adapted to generate and forward maintenance messages to the maintenance computer via the electronics system bus.

14. The vacuum toilet system of claim 10, characterised in that the universal controller (86f) is connected to both the flush valve (34) and rinse fluid valve (30) for operating the flush valve and rinse fluid valve in response to the flush command.

1 5. The vacuum toilet system of claim 14, characterised in that the system further comprises a sensor (66) associated with the collection tank (38) for detecting a high waste level in the collection tank and generating a tank full signal, the universal controller (86f) disabling the flush valve (34), rinse fluid valve (30), and flush actuator (37) in response to the tank full signal.

1 6. The vacuum toilet system of claim 1 0, characterised in that the universal controller (86f) is connected to the vacuum generator (56) and at least one of the flush valve (34) and rinse valve (30), the vacuum toilet system (10) further comprising a vacuum level sensor (66) associated with the collection tank (38) for generating a vacuum level signal coupled to the universal controller, the universal controller operating the vacuum generator in response to the vacuum level signal.

1 7. The vacuum toilet system of claim 1 0, characterised in that the universal controller (86f) further includes a power distribution module.

1 8. The vacuum toilet system of claim 1 0, characterised in that the system further comprises a second toilet (1 8a) having an outlet (22) in fluid communication with the collection tank (38), a second flush valve (34) disposed between the second toilet outlet (22) and the collection tank (38), a second rinse fluid nozzle (24) associated with the second toilet (1 8a) and adapted for connection to the rinse fluid source (28), a second rinse fluid valve (30) disposed between the second rinse fluid nozzle (24) and the rinse fluid source (28), and a second flush actuator (37) coupled to the second flush valve (34) and second rinse fluid valve (30), wherein the universal controller (86a) is further connected to and controls at least one of the second flush valve (34), second rinse fluid valve (30) , and second flush actuator (37).

1 9. A vacuum toilet system for use with a rinse fluid source (28), characterised in that the vacuum toilet system comprises: a toilet (1 8f) having an outlet (22); a collection tank (38) in fluid communication with the toilet outlet (22); a vacuum generator (56) in fluid communication with the collection tank (38), the vacuum generator operable to produce a partial vacuum in the collection tank; a flush valve (34) disposed between the toilet outlet (22) and the collection tank (38), the flush valve operable to control fluid communication between the collection tank and the toilet outlet; a rinse fluid valve (30) disposed between the rinse fluid source (28) and the toilet ( 1 8f) operable to establish fluid communication between the rinse fluid source and toilet, thereby delivering rinse fluid; a flush actuator (37) associated with the flush valve (34) and rinse fluid valve (30), the flush actuator operable to generate a flush command; and a universal controller (86f) and power distribution module adapted for connection to at least one of the flush valve (34), flush actuator (37), rinse fluid valve (30), and vacuum generator (56).

20. The vacuum toilet system of claim 1 9, characterised in that the universal controller (86f) and power distribution module are connected to the flush valve (34), flush actuator (37), and rinse fluid valve (30) for controlling operation of the flush valve and rinse fluid valve in response to the flush command.

21 . The vacuum toilet system of claim 20, characterised in that the system further comprises a sensor (66) associated with the collection tank (38) for detecting a high waste level in the collection tank and generating a tank full signal, the universal controller (86f) and power distribu- tion module disabling the flush valve (34), rinse fluid valve (30), and flush actuator (37) in response to the tank full signal.

22. The vacuum toilet system of claim 1 9, characterised in that the universal controller (86f) and power distribution module are connected to the vacuum generator (56), the vacuum toilet system ( 1 0) further comprising a vacuum level sensor (64) associated with the collection tank (38) for generating a vacuum level signal coupled to the universal controller (86f), the universal controller and power distribution module operating the vacuum generator in response to the vacuum level signal.

23. The vacuum toilet system of claim 1 9, characterised in that the system further comprises a second toilet ( 1 8a having an outlet (22) in fluid communication with the collection tank (38), a second flush valve (34) disposed between the second toilet outlet (22) and the collection tank (38), a second rinse fluid nozzle (24) associated with the second toilet (1 8a) and adapted for connection to the rinse fluid source (28), a second rinse fluid valve (30) disposed between the second rinse fluid nozzle (24) and the rinse fluid source (28), and a second flush actuator (37) coupled to the second flush valve (34) and second rinse fluid valve (30), wherein a universal controller (86a) and power distribution module is further connected to and controls at least one of the second flush valve (34), second rinse fluid valve (30), and second flush actuator (37).

24. A vacuum toilet system for use with a rinse fluid source (28), characterised in that the vacuum toilet system comprises: a collection tank (38); a vacuum generator (56) in fluid communication with the collection tank (38), the vacuum generator operable to produce a partial vacuum in the collection tank; a first toilet (1 8f; 1 52) having a first outlet (22) in fluid communication with the collection tank (38), a first flush valve (34) disposed between the first toilet outlet (22) and the collection tank (38) operable to control fluid communication between the collection tank and first toilet outlet, a first rinse fluid valve (30) disposed between the rinse fluid source (28) and the toilet (1 8f) operable to establish fluid communication between the rinse fluid source and the first toilet, thereby delivering rinse fluid to the first toilet, and a first flush actuator (37) associated with the first flush valve (34) and first rinse fluid valve (30) operable to generate a first toilet flush command; a second toilet (1 8a; 1 54) having a second outlet (22) in fluid communication with the collection tank (38), a second flush valve (34) disposed between the second toilet outlet (22) and the collection tank (38) operable to control fluid communication between the collection tank and second toilet outlet, a second rinse fluid valve (30) disposed between the rinse fluid source (28) and the second toilet (1 8a) operable to establish fluid communication between the rinse fluid source and the second toilet, thereby delivering rinse fluid to the second toilet, and a second flush actuator (37) associated with the second flush valve (34) and second rinse fluid valve (30) operable to generate a second toilet flush command; and a universal controller (86f,86a; 1 50) connected to and controlling at least one of the first flush valve (34; 1 58), first rinse fluid valve (30; 1 60), and first flush actuator (37; 1 56), and at least one of the second flush valve (34; 1 64), second rinse fluid valve (30; 1 66), and second flush actuator (37; 1 62).

25. The vacuum toilet system of claim 24, characterised in that the universal controller (86f,86a; 1 50) is connected to the first flush valve (34;1 58), first rinse fluid valve (30;1 60), and first flush actuator (37;1 56) for controlling operation of the first flush valve and first rinse fluid valve in response to the first toilet (1 8f; 1 52) flush command, and to the second flush valve (34;1 64), second rinse fluid valve (30;1 66), and second flush actuator (37; 1 62) for controlling operation of the second flush valve and second rinse fluid valve in response to the second toilet (1 8a; 1 54) flush command.

26. The vacuum toilet system of claim 25, characterised in that the universal controller (86f,86a;1 50) is further connected to the vacuum generator (56).

27. The vacuum toilet system of claim 25, characterised in that the system further comprises a sensor (66) associated with the collection tank (38) for detecting a high waste level in the collection tank and generating a tank full signal, the universal controller (86f,86a; 1 50) disabling the first and second flush valves (34; 1 58, 1 64), first and second rinse fluid valves (30; 1 60,1 66), and first and second flush actuators (37; 1 56, 1 62) in response to the tank full signal.

28. The vacuum toilet system of claim 24, characterised in that the universal controller (86f,86a; 1 50) further includes a power distribution module.

29. The vacuum toilet system of claim 24, characterised in that the universal controller (86f,86a; 1 50) is connected to the vacuum generator (56), the vacuum toilet system ( 1 0) further comprising a vacuum level sensor (64) associated with the collection tank (38) for generating a vacuum level signal coupled to the universal controller, the universal controller operating the vacuum generator in response to the vacuum level signal.