Abstract:
A gutter-cleaning device includes a body defining a forward drive direction and configured to fit into a residential gutter. The device also includes a drive system supporting the body and configured to maneuver across the gutter. A driven impeller disposed on the body defines an axis of rotation. The impeller has at least one agitator oriented about the axis of rotation. The axis of rotation is arranged at an angle to the forward drive direction to aim toward an inside corner of the gutter to eject agitated debris from the gutter and away from the impeller.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This U.S. patent application is a continuation of, and claims priority under 35 U.S.C. §120 from, U.S. patent application Ser. No. 12/984, 158, filed on Jan. 4, 2011, which is a continuation of U.S. patent application Ser. No. 12/027,968 filed Feb. 7, 2008, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application 60/984,836, filed Nov. 2, 2007. 
     U.S. patent application Ser. No. 12/027,968 is a continuation-in-part of, and claims priority under 35 U.S.C. §120 from, U.S. patent application Ser. No. 11/834,908, filed Aug. 7, 2007, which claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application 60/838,100, filed on Aug. 15, 2006. 
     The disclosures of all these prior applications are considered part of the disclosure of this application and are hereby incorporated by reference in their entireties. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to systems and methods for robotic gutter cleaning. 
     BACKGROUND 
     Cleaning debris from a gutter may be difficult and dangerous, especially when an individual uses a ladder to reach the gutter and leans laterally to reach portions of the gutter for cleaning. 
     SUMMARY 
     Provided herein may be methods and systems for gutter cleaning and a gutter-cleaning device thereof. In an aspect of the disclosure, a gutter-cleaning device includes a housing containing an impeller drive facility, the housing configured to fit into a gutter; an impeller, disposed at an end of the housing and driven by the impeller drive facility; and a transport facility for transporting the housing along the gutter. In the device, the impeller may be removably connected. In the device, the impeller drive facility may include a transmission. In the device, the impeller may be a rotating impeller. In the device, the impeller may be configured to remove debris from a gutter. In the device, the housing may include an energy storage facility. In the device, the device may further include a placement facility for facilitating placement of the gutter-cleaning device into a gutter. A placement pole, optionally telescoping, may attach to a placement facility to facilitate placing the gutter-cleaning device in the gutter. The placement facility may be spring-loaded to keep the placement facility vertical unless a lateral force is applied to the placement facility. In the device, the device may further include a control facility. The control facility may include an antenna. The antenna may be integrated with a placement facility. The control facility may be a remote control facility. The remote control facility may include a wireless communication facility. In the device, the transport facility may include a rotational transport facility. In the device, the device may further include an impeller chute for housing a portion of the impeller, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. In the device, the device may further include debris tines disposed at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. The impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. The impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the device, the transport facility may be at least one of a wheel, a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, and a string of beads drive. The wheel may be at least one of a tractor/tread wheel and tractor treads/tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, plastic wheels, molded elastomer wheels, and metal wheels. The wheel may be connected through an axle to a drive shaft. In the device, the device may further include a vision system disposed on the housing for facilitating navigation and programming of the device. The vision system may include a solid state camera, a camera lens, and a video signal electronics module. In the device, the device may further include a moisture sensor for detecting prohibitive levels of moisture in a gutter. In the device, the transport facility and the impeller drive facility may each control both transport and impellers. In the device, the device may further include at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. The vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the device, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. In the device, the device may further include a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. In the device, the device may further include an energy storage facility connected to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. In the device, the device may further include a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. 
     In an aspect of the disclosure, a gutter cleaning system includes a gutter-cleaning device, further including: a housing, the housing configured to fit into a gutter; and an impeller, disposed at an end of the housing and driven by an impeller drive facility; and a placement pole, optionally telescoping, operably connected to the gutter-cleaning device, further including: an impeller drive facility electrically connected to an impeller, optionally, a transport facility for transporting the housing along the gutter; and an energy storage facility electrically connected to the impeller drive facility and the transport facility for providing power. In the device, the impeller may be removably connected. In the device, the impeller drive facility may include a transmission. In the device, the impeller may be a rotating impeller. In the device, the impeller may be configured to remove debris from a gutter. In the device, the housing may include an energy storage facility. In the device, the device may further include a control facility. The control facility may include an antenna. The control facility may be a remote control facility. The remote control facility may include a wireless communication facility. In the device, the transport facility may include a rotational transport facility. In the device, the device may further include an impeller chute for housing a portion of the impeller, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. In the device, the device may further include debris tines disposed at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. The impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. The impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the device, the transport facility and the impeller drive facility may each control both transport and impellers. In the device, the device may further include at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. The vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the device, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. In the device, the device may further include a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. In the device, the device may further include an energy storage facility connected to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. In the device, the device may further include a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. In the device, the placement pole may be removably associated with the gutter-cleaning device. 
     In an aspect of the disclosure, a method of a gutter-cleaning device may include providing a housing containing an impeller drive facility, the housing configured to fit into a gutter; disposing an impeller at an end of the housing and driving the impeller with the impeller drive facility; and providing a transport facility for transporting the housing along the gutter. In the method, the impeller may be removably connected. In the method, the impeller drive facility may include a transmission. In the method, the impeller may be a rotating impeller. In the method, the impeller may be configured to remove debris from a gutter. In the method, the housing may include an energy storage facility. The method may further include providing a placement facility for facilitating placement of the gutter-cleaning device into a gutter. A placement pole, optionally telescoping, may attach to a placement facility to facilitate placing the gutter-cleaning device in the gutter. The placement facility may be spring-loaded to keep the placement facility vertical unless a lateral force is applied to the placement facility. The method may further include providing a control facility. The control facility may comprise an antenna. The antenna may be integrated with a placement facility. The control facility is a remote control facility. The remote control facility may include a wireless communication facility. In the method, the transport facility may include a rotational transport facility. The method may further include housing a portion of the impeller in an impeller chute, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. The method may further include disposing debris tines at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. In the method, the impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. In the method, the impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the method, the transport facility may be at least one of a wheel, a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, and a string of beads drive. The wheel may be at least one of a tractor/tread wheel and tractor treads/tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, plastic wheels, molded elastomer wheels, and metal wheels. The wheel may be connected through an axle to a drive shaft. The method may further include disposing a vision system disposed on the housing for facilitating navigation and programming of the device. The vision system may include a solid state camera, a camera lens, and a video signal electronics module. The method may further include providing a moisture sensor for detecting prohibitive levels of moisture in a gutter. In the method, the transport facility and the impeller drive facility may each control both transport and impellers. The method may further include providing at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. In the method, the vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the method, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. The method may further include providing a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. The method may further include connecting an energy storage facility to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. The method may further include providing a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. 
     In another aspect of the disclosure, a method of gutter cleaning, may include providing a gutter-cleaning device, including: a housing, the housing configured to fit into a gutter; and an impeller, disposed at an end of the housing and driven by an impeller drive facility; and providing a placement pole, optionally telescoping, operably connected to the gutter-cleaning device, including: an impeller drive facility electrically connected to an impeller, optionally, a transport facility for transporting the housing along the gutter; and an energy storage facility electrically connected to the impeller drive facility and the transport facility for providing power. In the method, the impeller may be removably connected. In the method, the impeller drive facility may include a transmission. In the method, the impeller may be a rotating impeller. In the method, the impeller may be configured to remove debris from a gutter. In the method, the housing may include an energy storage facility. The method may further include providing a control facility. The control facility may comprise an antenna. The control facility is a remote control facility. The remote control facility may include a wireless communication facility. In the method, the transport facility may include a rotational transport facility. The method may further include housing a portion of the impeller in an impeller chute, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. The method may further include disposing debris tines at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. In the method, the impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. In the method, the impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the method, the transport facility may be at least one of a wheel, a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, and a string of beads drive. The wheel may be at least one of a tractor/tread wheel and tractor treads/tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, plastic wheels, molded elastomer wheels, and metal wheels. The wheel may be connected through an axle to a drive shaft. The method may further include disposing a vision system disposed on the housing for facilitating navigation and programming of the device. The vision system may include a solid state camera, a camera lens, and a video signal electronics module. The method may further include providing a moisture sensor for detecting prohibitive levels of moisture in a gutter. In the method, the transport facility and the impeller drive facility may each control both transport and impellers. The method may further include providing at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. In the method, the vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the method, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. The method may further include providing a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. The method may further include connecting an energy storage facility to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. The method may further include providing a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. In the method, the placement pole may be removably associated with the gutter-cleaning device. 
     In an aspect of the disclosure, a gutter-cleaning device includes a housing containing an impeller drive facility, the housing configured to fit into a gutter; an impeller, disposed at an end of the housing and driven by the impeller drive facility; and a transport facility for transporting the housing along the gutter, wherein the transport facility enables gutter corner turning. In the device, the impeller may be removably connected. In the device, the impeller drive facility may include a transmission. In the device, the impeller may be a rotating impeller. In the device, the impeller may be configured to remove debris from a gutter. In the device, the housing may include an energy storage facility. In the device, the device may further include a placement facility for facilitating placement of the gutter-cleaning device into a gutter. A placement pole, optionally telescoping, may attach to a placement facility to facilitate placing the gutter-cleaning device in the gutter. The placement facility may be spring-loaded to keep the placement facility vertical unless a lateral force is applied to the placement facility. In the device, the device may further include a control facility. The control facility may include an antenna. The antenna may be integrated with a placement facility. The control facility may be a remote control facility. The remote control facility may include a wireless communication facility. In the device, the transport facility may include a rotational transport facility. In the device, the device may further include an impeller chute for housing a portion of the impeller, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. In the device, the device may further include debris tines disposed at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. The impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. The impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the device, the transport facility may be at least one of a wheel, a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, and a string of beads drive. The wheel may be at least one of a tractor/tread wheel and tractor treads/tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, plastic wheels, molded elastomer wheels, and metal wheels. The wheel may be connected through an axle to a drive shaft. In the device, the device may further include a vision system disposed on the housing for facilitating navigation and programming of the device. The vision system may include a solid state camera, a camera lens, and a video signal electronics module. In the device, the device may further include a moisture sensor for detecting prohibitive levels of moisture in a gutter. In the device, the transport facility and the impeller drive facility may each control both transport and impellers. In the device, the device may further include at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. The vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the device, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the device, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. In the device, the device may further include a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. In the device, the device may further include an energy storage facility connected to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. In the device, the device may further include a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. 
     In an aspect of the disclosure, a method of a gutter-cleaning device may include providing a housing containing an impeller drive facility, the housing configured to fit into a gutter; disposing an impeller at an end of the housing and driving the impeller with the impeller drive facility; and providing a transport facility for transporting the housing along the gutter, wherein the transport facility enables gutter corner turning. In the method, the impeller may be removably connected. In the method, the impeller drive facility may include a transmission. In the method, the impeller may be a rotating impeller. In the method, the impeller may be configured to remove debris from a gutter. In the method, the housing may include an energy storage facility. The method may further include providing a placement facility for facilitating placement of the gutter-cleaning device into a gutter. A placement pole, optionally telescoping, may attach to a placement facility to facilitate placing the gutter-cleaning device in the gutter. The placement facility may be spring-loaded to keep the placement facility vertical unless a lateral force is applied to the placement facility. The method may further include providing a control facility. The control facility may comprise an antenna. The antenna may be integrated with a placement facility. The control facility is a remote control facility. The remote control facility may include a wireless communication facility. In the method, the transport facility may include a rotational transport facility. The method may further include housing a portion of the impeller in an impeller chute, wherein debris may be rotated against the chute by the impeller prior to ejection from the gutter. The method may further include disposing debris tines at one or both ends of the gutter-cleaning device to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be formed from at least one of metal, wood, plastic, and molded elastomer. The debris tines may be coated with a solid debris removal solvent. In the method, the impeller may be formed from at least one of a molded elastomer, neoprene, rubber, plastic, and an electrostatic cloth. In the method, the impeller may be at least one of a helical-bristled brush, a flexible paddle, a full stiff bristle brush, a spiral stiff bristle brush, a wire brush, a dethatching brush, an alternating paddle brush, a flexible bucket, a multiply-vaned impeller, and an alternating flexible blade. In the method, the transport facility may be at least one of a wheel, a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, and a string of beads drive. The wheel may be at least one of a tractor/tread wheel and tractor treads/tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, plastic wheels, molded elastomer wheels, and metal wheels. The wheel may be connected through an axle to a drive shaft. The method may further include disposing a vision system disposed on the housing for facilitating navigation and programming of the device. The vision system may include a solid state camera, a camera lens, and a video signal electronics module. The method may further include providing a moisture sensor for detecting prohibitive levels of moisture in a gutter. In the method, the transport facility and the impeller drive facility may each control both transport and impellers. The method may further include providing at least one of an on-board tool or attachment, a downspout cleaning tool, an air hose attachment, a water hose attachment, a vacuum facility, and a weed whacker attachment. In the method, the vacuum facility may provide a vacuum through at least one of the impellers, the impeller vane attachment point, the housing, and a vacuum hose attachment. In the method, the impeller drive facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the transport facility may be at least one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, and a solar-powered motor. In the method, the housing may be formed from at least one of metal, plastic, molded elastomer, weather-resistant materials, water-resistant materials, solvent-resistant materials, temperature-resistant materials, shock-resistant materials, and breakage-resistant materials. The method may further include providing a navigation system to facilitate autonomous control of the device. The navigation system may be integrated with at least one of a proximity sensor, a vision system, a programming facility, and a moisture sensor. The method may further include connecting an energy storage facility to the transport and impeller drives for providing power. The energy storage facility may be at least one of a battery, a gasoline fuel or biofuel tank, and a solar panel. The battery may be at least one of rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, and nickel oxyhydroxide. The method may further include providing a programming facility to set programs for autonomous control. Programming may be done by at least one of wirelessly and a direct connection to a programming interface. 
     In an aspect of the disclosure, a downspout cleaning tool may comprise an energy facility for driving a motor, wherein both are housed within a hemispherical housing, and a gear train associated with the motor for providing rotational power to the hemispheres. In an embodiment, hemispheres comprise vanes. In an embodiment, hemispherical rotation may be synchronized or may be a counter-rotation. In an embodiment, the tool may be disposed by a user into a downspout. In an embodiment, the tool may be disposed by a gutter-cleaning device into a downspout. 
     In an aspect of the disclosure, a downspout cleaning tool may comprise at least two expandable grippers disposed on either end of a bellows, wherein expansion of the grippers enables securing the tool to a downspout wall, an elongatable and contractable bellows for moving the tool in a direction along the downspout, and an impeller disposed on a gripper for clearing a downspout, wherein the grippers may expand and contract at different times to enable the bellows to contract and elongate in order to move the tool along the downspout. In an embodiment, the grippers may be expanded by compressed air or manually. In an embodiment, the electronics and energy storage facility are housed within the bellows. 
     In one aspect, an apparatus for cleaning a gutter that is disclosed herein includes a housing adapted to fit into a gutter, an impeller drive facility connected to the housing; an impeller connected to the impeller drive facility, the impeller having an axis of rotation, the axis of rotation oriented toward an inside corner of the gutter, the impeller drive facility adapted to rotate the impeller on the axis of rotation; and a transport drive connected to the housing, the transport drive adapted to transport the housing through the gutter, transport of the housing through the gutter causing the impeller to travel along an axis of motion, the axis of motion differing from the axis of rotation. The impeller may include a blade extending past a rotating joint, the rotating joint between the impeller and the rest of the apparatus. The impeller may include a flexible blade adapted both to deflect when brought into contact a wall of the gutter and to release when brought out of contact with the wall of the gutter. The apparatus for cleaning a gutter may include a spherical bearing disposed on the impeller, wherein the impeller is tapered and has a tip, the bearing disposed at the tip. 
     In one aspect, an apparatus for cleaning a gutter that is disclosed herein includes a housing adapted to fit into a gutter, the housing having a longitudinal axis; an impeller drive facility connected to the housing; and a circuit both disposed inside the housing and operatively coupled to the impeller drive facility, wherein the circuit is adapted to communicate a control signal to the impeller drive facility, the control signal responsive to a rotation about the longitudinal axis. The control signal may be adapted to reduce a torque of the impeller drive facility. The control signal may be adapted to reverse a torque of the impeller drive facility. The circuit may contain a sensor selected from the group consisting of a gyroscope and an accelerometer. The apparatus for cleaning a gutter may include a second impeller drive facility both connected to the housing and operatively coupled to the circuit, wherein the circuit is further adapted to communicate a second control signal to the second impeller drive facility, the second control signal responsive to the rotation about the longitudinal axis. 
     The details of one or more implementations of the disclosure are set forth in the accompanying drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings, and from the claims. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  depicts a system for gutter cleaning. 
         FIG. 2  is a perspective view of the gutter cleaning system showing the internal mechanical system elements. 
         FIG. 3  is an illustration showing the placement of the gutter cleaning system into a gutter. 
         FIG. 4  is an illustration showing the control of the gutter cleaning system from the ground. 
         FIG. 5  is a partial section view showing the system elements. 
         FIG. 6  is a partial section view showing the system elements. 
         FIG. 7  is a cross sectional view showing the operation within the gutter. 
         FIG. 8  is an illustration showing the range of impellers that may accomplish gutter cleaning. 
         FIG. 9  depicts a cross section of an exemplary gutter-cleaning device. 
         FIG. 10  depicts a gutter-cleaning device remote control. 
         FIG. 11  depicts a gutter-cleaning device disposed in a gutter. 
         FIG. 12  depicts a gutter-cleaning device. 
         FIG. 13  depicts a gutter-cleaning device. 
         FIG. 14  depicts a gutter-cleaning device. 
         FIG. 15  depicts a cutaway view of a gutter-cleaning device. 
         FIG. 16  depicts a cutaway view of a gutter-cleaning device. 
         FIG. 17  depicts a cutaway view of a gutter-cleaning device. 
         FIG. 18  depicts a transport drive motor. 
         FIGS. 19-25  depict a corner turning gutter cleaning device turning a corner in a gutter. 
         FIG. 26  depicts a corner turning, gutter cleaning remotely operated vehicle. 
         FIG. 27  depicts a downspout dervish cleaning robot. 
         FIG. 28  depicts a downspout inchworm cleaning robot. 
         FIG. 29  depicts a front perspective view of an apparatus for cleaning a gutter, the apparatus in a gutter. 
         FIG. 29A  depicts a top perspective view of an apparatus for cleaning a gutter, the apparatus in a gutter. 
         FIG. 30  depicts a perspective, partially transparent view of an apparatus for cleaning a gutter. 
     
    
    
     Like reference symbols in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     Throughout this disclosure the phrase “such as” means “such as and without limitation.” Throughout this disclosure the phrase “for example” means “for example and without limitation.” Throughout this disclosure the phrase “in an example” means “in an example and without limitation.” Throughout this disclosure the phrase “in another example” means “in another example and without limitation.” Generally, any and all examples may be provided for the purpose of illustration and not limitation. 
     In some implementations, a robotic drainage channel (gutter) cleaning system may include a remotely operated device for cleaning drainage channels, or “gutters” and methods thereof. Gutter cleaning may involve removing debris, such as leaves, bark, twigs, nut shells, nuts, airborne matter, bird&#39;s nests, ice, water, foreign objects, and any other matter that may accumulate in a gutter. The gutter cleaning system may comprise an impeller, a chute at each end of the device that may facilitate the debris removal action, a impeller power module that drives the impeller, a transport mechanism that moves the device either way along the trough of the gutter, a impeller power module that drives the transport mechanism (which may be the same as for the impeller if so designed), an energy storage system, a communication module, a spring mounted device placement hook/visual indicator, a handheld remote controller, a placement mechanism, and the like. A user of the gutter cleaning system may deploy a gutter-cleaning device  104  into a gutter with the use of a pole with a hook on its end. A wireless remote control may permit the user to move the gutter-cleaning device  104  along the length of the gutter while the device disposes accumulated debris out of the gutter. 
     Referring to  FIG. 1 , a gutter cleaning system  102  may comprise gutter-cleaning device  104 , a transport facility  150 , an impeller power module  128 , a control facility  160 , and a programming facility  170 . The gutter-cleaning device  104  may comprise an impeller  108 , a chute  110 , a debris tine  112 , a vacuum  114 , an impeller hub  118 , on-board tools or attachments  120 , a moisture sensor  122 , a vision system  124 , a placement facility  174 , and the like. An impeller power module  128  may comprise an impeller transmission  130 , an impeller drive facility  138 , an energy storage facility  142 , and the like. A transport facility  150  may comprise a housing  152 , a transport drive  154 , a navigation system  158 , a wheel  172 , a transport transmission  174 , and the like. A control facility  160  may comprise an antenna  162 , a wireless communication facility  164 , a remote control  168 , and the like. A programming facility  170  may enable programming and re-programming the gutter-cleaning device  104 . 
     Referring now to  FIG. 2 , an impeller  108  located at an end of a gutter-cleaning device  104 , a chute  110  housing for the impeller, debris tines  112 , an impeller drive facility  138 , a housing  152 , a transport drive  154 , a wheel  172 , an energy storage facility  142 , a placement facility  174 , and the like. The gutter-cleaning device  104  is configured and disposed to move along the length of a gutter while disposing the accumulated debris out of the gutter. The impeller  108  is configured to capture gutter debris for removal from the gutter. The impeller  108  may be connected to at least one end of the gutter-cleaning device  104 . In some embodiments, an impeller  108  may be located on both ends of a gutter-cleaning device  104 , attached by an impeller hub  118  to an impeller drive shaft  208 . An energy storage facility may provide power to an impeller drive facility  138  to rotate the impeller about its central axis. As the impeller  108  rotates, the impeller vanes  702  may capture accumulated debris either between the vanes  702  or against an impeller chute  110  disposed around a portion of the impeller. The rotational torque of the impeller  108  may move the captured debris against the surface of the chute  110  or the gutter wall. At the top end of the chute  110  or the gutter, the gutter debris may be discharged at a high enough velocity such that the debris may clear the outside wall of the gutter. Once clear of the gutter, the debris may fall to the ground, may be captured in a disposal bag attached to the gutter, may be captured in a disposal bag attached to the gutter-cleaning device  104 , or the like. The impeller  108  may be easily removable to facilitate cleaning, replacement, storage, shipping, disposal, and the like. In an embodiment, the impellers  108  may comprise many different materials such as molded elastomer, neoprene, rubber, plastic, electrostatic cloth, and the like. Referring to  FIG. 8 , in an embodiment, the impellers  108  may comprise many different impeller configurations, such as a helical-bristled brush, flexible paddles  802 , a full stiff bristle brush  804 , a spiral stiff bristle brush  808 , a wire (dethatching) brush  810 , an alternating paddle brush  812 , a flexible bucket  814 , an alternating flexible blade  818 , and the like. In embodiments, a single impeller may comprise different impeller vanes, such as any of the vanes associated with the impellers described herein. In embodiments, the impellers  108  on one or both ends of the device  104  may be detachable and interchangeable with any impeller configuration. The impeller  108  may have multiple impeller vanes  702  disposed about a central attachment point. Each impeller vane  702  may be flexible to facilitate deflection under gutter cross braces and movement against chute  110 , gutter walls, and gutter floor. In an embodiment, the impeller vanes may be of the same dimension or of different dimensions. In an embodiment, the impellers may be sized to span the gutter, exceed the span of the gutter, fall short of spanning the gutter, span portions of debris, or a combination thereof. In an example, the impeller may be four-inches in diameter and 3 inches in length. In an embodiment, the impellers may be compliant enough such that they deform under pressure. In an example, the compliant deformation may be 0.75″ inward with one pound of force. In an embodiment, the impeller  108  may comprise a vacuum facility  114  disposed within the gutter-cleaning device  104  and a vacuum motor disposed within the housing  152 . The vacuum facility  114  may provide suction through the impellers, the impeller vane attachment point, the housing  152 , and the like in order to loosen debris from the gutter. In an alternative embodiment, the impeller head may be replaced with a vacuum hose attachment. As the gutter-cleaning device  104  moves along the gutter, the vacuum  114  attachment may vacuum up debris and remove it from the gutter. Removal may be through a collection hose attached to a collection bag, a yard waste receptacle, a mulching or composting system, and the like. In this embodiment, a vacuum  114  motor may be disposed within the housing  152  or in a separate structure. 
     In an embodiment, the chute  110  may be a housing for at least a portion of the impeller  108 . In embodiments, the chute  110  may not protrude above the top line of the gutter-cleaning device  104 , may not interfere with gutter cross braces, may be deformable to permit passage under gutter cross braces, and the like. 
     In an embodiment, the debris tines  112  may be connected to one or both ends of the gutter-cleaning device  104 . The debris tines  112  may be configured and disposed to loosen and lift matted debris from the bottom and sides of the gutter into the impeller. The debris tines may be attached to a lower part of the housing  152  or the sides of the housing  152  at the ends of the gutter-cleaning device  104 . The debris tines  112  may be formed from almost any material, including metal, wood, plastic, molded elastomer, nylon, boar bristle, and the like. To facilitate debris loosening, the debris tines  112  may be coated with a solid debris removal solvent. Before placement of the gutter-cleaning device  104  into the gutter, the solid debris removal solvent may be activated by placing water on the debris tines  112 . In an alternative embodiment, debris removal solvent may be disposed within the housing  152 . When the impellers  108  may be activated, some solvent may be applied to the gutter surface using a spray, a simple gravity fed system, and the like. 
     In an embodiment, the impeller drive module  138  may be configured and disposed to drive the impeller  108  with any necessary rotational speed and torque. The impeller drive module  138  may be coupled to the impeller and housed within the housing  152 . In some embodiments, the impeller drive module  138  may comprise a motor or engine and a speed/torque modifying transmission  130 . The motor may be any one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, a solar-powered motor, and the like. In an embodiment, the motor may be a 12 Volt DC single speed motor with transfer gearing to an impeller drive shaft  208 . Motor cooling may be on a top surface of the gutter-cleaning device  104  and may minimize fluid entry to the device. In some embodiments, the motor may be mechanically coupled to the drive transmission  130  such that the rotational output of the drive motor  138  is a rotational input to the drive transmission  130 . The rotational output of the impeller transmission  130  may rotate the wheel  152  about its central axis. 
     In an embodiment, the impeller drive module  138  may comprise a motor or engine connected directly to an output without any intervening speed/torque modifying transmission  130 . In an embodiment, the impeller drive facility  138  may operate at 400 rpm @ 300 in·lbs. of torque. In an embodiment, the motor may work with both the impeller drive module  138  as well as the transport drive  154 . 
     In an embodiment, the impeller transmission  130  comprises transfer gear driving. A gear may be coupled to a selector fork with a transfer shaft delivering power to the wheels  152  with power take-offs. 
     In an embodiment, a transport facility  150  may comprise a housing  152 , a transport drive  154 , a navigation system  158 , a wheel  172 , and the like. The housing  152  may be formed from any suitable material, such as metal, plastic, molded elastomer, and the like. In an embodiment, the housing  152  materials may be weather-resistant, water-resistant, solvent-resistant, temperature-resistant, shock-resistant, breakage-resistant, and the like. All of the components of the gutter-cleaning device  104 , including at least the housing  152 , impellers  108 , debris tines  112 , on-board tools/attachments  120 , control facility  160 , transport facility  150 , and the like may be easy to clean. The housing  152  may be able to withstand all manners of environmental phenomena and exposure. The housing  152  may be able to withstand falls from the gutter onto a surface, such as concrete, asphalt, stone, grass, roofing, and the like. The housing  152  may provide weight to the gutter-cleaning device  104  such that the device may exert any necessary force on the impeller  108  to detach debris. In some embodiment, the gutter-cleaning device  104  may not be so heavy as to negate the possibility of lifting the gutter-cleaning device  104  the height of the gutter for placement within the gutter. The housing  152  may be sized to house the internal components of the gutter-cleaning device  104 . The cross sectional dimensions of the housing  152  and gutter-cleaning device  104  may be limited by the size of a gutter, such as no more than 2.75″ high and 3.0″ wide. 
     In an embodiment, the transport drive  154  may be connected to at least one wheel  172 , a snake drive, a worm drive, a crab or walking drive, a scoot-and-compress or accordion drive, a string of beads drive, other translation mechanisms, and the like. The transport drive  154  may be housed within the housing  152  of the gutter-cleaning device  104 . The wheels may be tractor/tread wheels and tracks, finned hemispherical wheels, rubber wheels, vulcanized wheels, and the like. The transport drive  154  may be configured and disposed to provide rotational speed and torque to the wheel  172  or other transport facility  150  in a sufficient amount to drive the gutter-cleaning device  104 . The transport drive  154  may comprise a motor or engine and a transmission  174 . The motor may be any one of a reversing gear motor, an electric motor, a gasoline- or biofuel-powered internal combustion engine, a solar-powered motor, and the like. In an embodiment, the motor may be a 12 Volt DC single speed motor with transfer gearing to an impeller drive shaft  208 . Motor cooling may be on a top surface of the gutter-cleaning device  104  and may minimize fluid entry to the device. The transmission  174  may be a speed/torque modifying transmission. The transport drive  154  may have a static or variable speed setting. The speed setting may be set in the factory or by a remote control  168 . For example, the speed may be set to 4 inches per second. In another example, a user may use a remote control  168  to modify the speed from a fast speed to a slow speed. The transport drive  154  may work with the wheel  172  or alternate translation mechanisms to move the gutter-cleaning device  104  within the gutter in either direction, such as forwards and backwards. 
     In an embodiment, the wheel  172  may be attached to an axle. The axles may be located fore and aft and may be transversely connected to one another. The axles may be connected through a drive shaft  208 . 
     In an embodiment, the navigation system  158  may facilitate navigation of the gutter-cleaning device  104  in the gutter. In embodiments, the navigation system  158  may comprise a proximity sensor, may be integrated with a vision system  124 , may be integrated with a moisture sensor  122 , may be integrated with a programming facility  170 , and the like. For example, the gutter-cleaning device  104  may have a proximity sensor on an end of the device to determine if the device is about to reach a gutter wall or turn. The gutter-cleaning device  104  may come to a halt or automatically reverse direction if it senses that it has reached the end of its travel. If the sensor detects that there may be a turn in the gutter, the gutter-cleaning device  104  may turn the corner and continuing its gutter cleaning In an embodiment, the gutter-cleaning device  104  may be segmented to facilitate turning or navigating around a gutter corner. In an embodiment, certain drives may facilitate corner turning, such as an accordion drive, a worm drive, a string of beads drive, and the like. In another example, a moisture sensor  122  disposed on the housing  152  of the device  104  may sense when water levels may be prohibitive to operation of a non-watertight housing  152 . The navigation system  158  may receive a signal from the moisture sensor  122  and modify, continue, or cease operation of the device  104 . The navigation system  158  may also be integrated with a vision system  124 , as discussed below. 
     In an embodiment, the gutter-cleaning device  104  may navigate around a corner without a navigation system  158 . For example, the device may be programmed to turn when it reaches a barrier. The device  104  may continue to search for an open path until it reaches one. In another example, the device  104  may be remote controlled to turn a corner. When a user sees or is otherwise aware that the device  104  is approaching a corner, the user may navigate the device  104  around the corner using a control facility  160 . 
     Referring to  FIGS. 19-25 , a gutter cleaning device  104  may navigate around a corner in a gutter.  FIGS. 19 through 25  depict the path a gutter cleaning device  104  may take navigating around a corner in a gutter. In these examples, the gutter cleaning device  104  may be partitioned into segments, or beads, wherein the main elements of the device  104  are housed in the beads. For example, the impeller power module  128  may be housed in the same bead as the impeller  108 . In the example depicted in  FIGS. 19-25 , the impellers  108  may be separately controlled by impeller power modules  128  disposed within the bead to which the impeller  108  is attached. Alternatively, the impeller power module  128  may be located in any other bead and may be electrically connected to the impeller(s)  108  on the end of the string of beads. In an embodiment, the components of the gutter-cleaning device  104  may be distributed in any manner along any number of beads comprising the housing  152  of the gutter-cleaning device  104 . 
     Referring to  FIG. 26 , a corner turning gutter cleaning Remote Operated Vehicle (ROV) device  104  is depicted. At each end of the device  104 , an approximately spherical impeller and impeller chute is disposed. An impeller core may house an internal motor that spins the impeller vanes. A torque coupling may drive the sphere with steering coupling to provide turn initiating inputs to the impeller. Tractor spheres may comprise drive motors, batteries, electronics, an antenna for a remote control system, and the like. The system may be left in the gutter to autonomously navigate the entire gutter, wherein the gutter may be at a single elevation. A docking module may be disposed within the gutter to allow recharging between gutter cleaning sorties. Any number of tractor spheres may be disposed along the device  104  to provide locomotive capability to the device  104 . The tractor spheres may have flexible, high-grip ribs or other traction pattern. In embodiments, the tractor sphere may comprise an internal drive motor which, through a speed reduction gearbox and differential, driveshaft brakes or some other control method may enable the control of rotational direction of the drive treads. The rotation may be synchronized or counter-rotating to provide steering input. Similarly, the impellers&#39; rotation may be synchronized or counter-rotating. 
     Continuing to refer to  FIG. 2 , an energy storage facility  142  may be housed within the housing  152  of the gutter-cleaning device  104  and electrically connected to the motors or engines of the impeller drive facility  138  and transport drive  154 . The energy storage facility  142  may be a battery. The battery may be rechargeable, disposable, lead-acid, gel, nickel cadmium, nickel metal hydride, lithium ion, zinc carbon, zinc chloride, alkaline, silver oxide, lithium ion disulphide, lithium thionyl chloride, mercury, zinc air, thermal, water activated, nickel oxyhydroxide, and the like. For example, a battery pack may supply 12 Volts DC at 2.2 Amp Hr. The rechargeable battery may comprise a recharging or docking station. The battery may be removable for docking or the entire device may be docked. In an embodiment, the docking station may be disposed at the end of a gutter. In this example, the gutter-cleaning device  104  may self-dock once a cleaning cycle is complete, if the battery is low, if directed to dock by a signal from a remote control  168 , and the like. An audible alert may indicate that the battery power level is low. 
     In an embodiment, the energy storage facility  142  may be a gasoline fuel or biofuel tank. The energy storage facility  142  may be a solar panel. In embodiments, there may be no energy storage facility  142  as energy may be drawn directly from a power outlet through a power cord. 
     In an embodiment, the gutter-cleaning device  104  may reside in the gutter. The gutter-cleaning device  104  may operate autonomously once it may be programmed. Programming may occur at the factory or may be done by a user using a programming facility  170 . The device  104  may be programmed to initiate a cleaning cycle at a timed interval, if the vision system  124  determines that there may be sufficient blockage present in an image, and the like. The cycle may be programmed to run for a pre-determined amount of time. In an alternate embodiment, the vision system  125  may interface with the programming facility  170  to provide an indication that no more debris remains in the gutter and that the program may be terminated. In some embodiments, the gutter-cleaning device  104  may comprise a pressure-sensitive surface such that when no debris remains and the pressure on the impeller  108 , the impeller vanes  702 , the chute  110 , and the like may be reduced, the program may be terminated. The programming facility  170  may be present on a remote control; programming may be accomplished wirelessly. In an alternate embodiment, the programming may be done by a direct connection to a programming interface. The gutter-cleaning device may have a connector configured to dock with a programming interface. For example, the device  104  may have a USB connector configured to allow access to a programming facility  170  when connected to a programming interface. The programming interface may a computer or the like. In embodiments, the programming interface may be a desktop application, a web page, and the like. 
     Referring now to  FIGS. 3 and 4 , a remotely operated wireless gutter cleaning system  102  is shown. The system  102  may include a placement pole  302 , a gutter-cleaning device  104 , a handheld wireless remote control unit  168 , a placement facility  174 , and the like. The placement facility  174  may be configured to receive an end of a placement pole  302 , such as an eyelet. The system  102  may be configured to allow a user to deploy the device  102  into a gutter with the use of a placement pole  302 , which may be configured with a hook on its end and remove the device once gutter cleaning may be complete. In some embodiment, the placement pole  302  is a telescoping pole. The gutter-cleaning device may be disposed and configured with a placement eyelet  174  connected to its top surface. The placement pole  302  may be telescoping to transport a gutter-cleaning device  104  to the height of the gutter and place the device within the gutter. In an alternative embodiment, the placement pole  302  may be used to lower the device  104  into the gutter from above using the placement pole  302 , a tether and/or latch hook, and the like. For example, a gutter-cleaning device  104  may be lowered into a gutter from a window. In an embodiment, the placement pole  302  may comprise a battery pack, transfer gears, motors and the like. Such an embodiment may be useful for various situations where the surface to be cleaned is not horizontal. For example, the device  104  configured to attach to a placement pole  302  comprising batteries, motors, and the like may be useful for chimney cleaning. The placement eyelet  174  may be configured and disposed to receive a hook on the end of a placement pole  302 , and to allow disengagement of the hook while the gutter-cleaning device  104  is in a gutter. As in  FIG. 4 , the placement eyelet may provide a visual cue of the location of the gutter-cleaning device  104  inside the gutter. In some embodiments, the protruding placement eyelet  174  may include a mirrored surface to provide a view of the gutter in front of and/or behind the device. The remote control  168  may permit a user to move the gutter-cleaning device  104  back and forth along the length of the gutter while the device  104  disposes of accumulated debris out of the gutter. 
     Continuing to refer to  FIG. 2 , in some embodiments, the gutter-cleaning device  104  may further include a spring loaded pivot swivel joint  202  and a flush position recess  204  for the placement facility  174 . The placement facility  174  may be connected to a spring loaded pivot swivel joint  202  connected to the body of the gutter-cleaning device  104 . The spring loaded pivot swivel joint  202  may be configured and disposed to keep the placement facility  174  vertical unless a lateral force may be applied to the placement facility  174 . The spring loaded pivot swivel joint  202  may allow the placement facility  174  to be forced flush to the body of the gutter-cleaning device  104  when it may encounter a gutter cross brace. The body of the gutter-cleaning device  104  may be configured with a flush position  203  on either one side or both sides of the spring loaded pivot swivel joint  202 . The flush position recess  204  may be configured to receive the placement facility  174  when it may encounter a side load. 
     Referring now to  FIG. 5 , an exemplary gutter-cleaning device may comprise an impeller  108  on both ends of the device  104 , a chute  110  for each impeller  108 , traction wheels  172 , an energy storage facility  142 , an impeller hub  118  for each impeller  108 , an impeller drive motor  138 , an impeller transmission  130 , an impeller drive shaft  208 , a wireless communication facility  164 , an antenna  162 , a traction tread  502 , a traction drive motor  154 , a fraction drive transmission  174 , and the like. The impeller hub  118  may be connected to the impeller  108  and mounted to an impeller drive shaft  208 . The impeller drive shaft  208  may be coupled to the impeller transmission  130  and configured to extend out each end of the impeller transmission  130  to connect to each impeller hub  118  at each end of the gutter-cleaning device  104 . The impeller drive motor  138  may be connected to the input of the impeller transmission  130 . In some embodiments, the gutter-cleaning device  104  may comprise impeller drive motors  138  mounted within the hub  118  of each impeller  118 . 
     Continuing to refer to  FIG. 5 , the wireless communication facility  164  may be electrically connected to the energy storage facility  142 , the impeller drive motor  138 , the traction drive motor  154 , the antenna  162 , and the like. The wireless communication facility  164  may be mounted within the gutter-cleaning device  104  housing  152 . The wireless communication facility  164  may be configured and disposed to control the impeller  108  actuation, wheel  172  actuation, antenna  162  actuation, and the like. The wireless communication facility  164  may control power delivery from the energy storage facility  174  to the drive motors  138 ,  154 . The wireless communication facility  164  may allow a user of a remote control  168  to change the direction of the device  104  in a gutter, change the speed of movement of the device  104 , change the speed of the impellers  108 , change the direction of rotation of the impellers  108 , operate an on board tool/attachment  120 , a vacuum  114 , a moisture sensor  122 , a vision system  124 , and the like. The remote control  168  may have a low battery alert, such as an audible alert, a visible alert, a vibration alert, and the like. The wireless communication facility  164  may be configured to receive communication signals from a remote control  168  via the antenna  162 . The antenna  162  may be electrically connected to the wireless communication facility  164  and may protrude up through the housing  152  of the gutter-cleaning device or may be disposed flush against the housing  152 . In some embodiments, the antenna  162  may be integrated in the placement facility  174 . In an embodiment, the wireless communication facility  164  may control the gutter-cleaning device  104  through a radio frequency link. The radio frequency link may be operable over a separation distance between the remote control  168  and the device  104 . In some embodiments, the wireless communication facility  164  may include appropriate signal processing capabilities to send communication signals such as a video signal back to the remote control  168  or some other signal reception device, such as a web browser, a desktop application, and the like. In some embodiments, the antenna may be configured to receive cellular signals, a network signal, and the like, facilitating control of the device through the wireless communication facility  164  from a cellular phone, a remote control  168 , a desktop application, an Internet application, and the like. 
     A traction tread  502  may be mounted to the traction wheels  172  on each side of the gutter-cleaning device  104 . The fraction tread  502  may be configured and disposed to provide traction for motive force. The traction drive motor  154  may be mechanically coupled to the fraction drive transmission  174  such that the rotational output of the traction drive motor  154  is a rotational input to the traction drive transmission  174 . The traction drive motor  154  and traction drive transmission  174  may be mounted within the housing  152  of the gutter-cleaning device  104 . The traction drive transmission  174  may be mechanically coupled to at least one traction wheel  172  such that the rotational output of the fraction drive transmission  174  may rotate the traction wheel  172  about its center axis. 
     Referring now to  FIG. 6 , in some embodiments a gutter-cleaning device  104  may comprise vision system  124 . The vision system  124  may comprise a solid state camera  602 , a camera lens  604 , and a video signal electronics module  608 . A solid state camera  602  may be mounted in the front of each impeller hub  118 , optionally on a center axis. A camera lens  604  may be mounted directly in front of the solid state camera  602  and may be configured and disposed to focus an image for the solid state camera  602 . The camera lens  604  may also protect the solid state camera  602  from being damaged by debris. The solid state camera  602  and the video signal electronics module  608  may interact to enable wireless transmission of a video signal. Images may be transmitted to a remote control  168  or some other signal reception device. Having seen the images, a user may modify, continue, or cease the operation of the device  104 . For example, if the images indicate that the gutter-cleaning device  104  is nearing a gutter wall, a user may slow down the device  104  then turn it off. If the images indicate that the gutter still has debris to clear, the user may continue to operate the gutter-cleaning device  104  in at least those portions of the gutter that still retain debris. Images may be used by a navigation system  158  to automatically modify, continue, or cease the operation of the device  104 . The navigation system  158  may process the images to determine if the system  158  should modify, continue, or cease the operation of the device  104 . In an example, the navigation system  158  may be used to navigate a right hand turn in the gutter. 
     Referring now to  FIG. 7 , a cross sectional view of the gutter-cleaning device  104  is shown within a gutter. The gutter-cleaning device  104  may comprise flexible impeller vanes  702 , compliant treads  710 , and the like. The gutter may comprise a sidewall  708  and at least one cross brace  704 . The impeller chute  110  may be configured and disposed such that it may be lower in height then the cross braces  704  of the gutter. In some embodiment, the impeller chute  110  may be at least the height of the cross braces  704  and may be compliant such that it may deflect under the cross braces  704 . The flexible impeller vanes  702  may be configured and disposed such that they may deflect under the cross braces  704  and/or against the bottom surface of the gutter. The shape and form factor of the impeller chute  110  may be one factor that may determine the average trajectory of the ejected debris. 
     Referring now to  FIG. 9 , a gutter profile  918  and an exemplary gutter-cleaning device  104  cross section  920 ,  922  are depicted. For example, a gutter-cleaning device  104  may comprise electronics  902 , a gearbox  904 , a 12 VDC motor  908 , a 12 VDC battery pack  910 , a 12 VDC high-torque motor  912 , a speed reduction gearbox  914 , and the like. 
     Referring to  FIG. 10 , an exemplary handheld remote control  168  comprising forward and reverse direction buttons, impeller  108  actuation and speed button, placement facility  174  retraction button, and the like. 
     Referring to  FIGS. 11 , an exemplary gutter cleaning is disposed in a gutter. 
     Referring to  FIGS. 12, 13, and 14 , exemplary gutter-cleaning devices are depicted. 
     Referring to  FIG. 15 , an exemplary gutter-cleaning device is shown in a cutaway view so that the internal elements are exposed. In this example, the gutter-cleaning device may comprise an impeller  108 , a drive shaft  208 , a housing  152 , a wheel  172 , an impeller end-cap  1504  to facilitate securing and removal of the impeller  108 , traction tread  502 , an air vent  1502  in a portion of the housing  152 , and the like. 
     Referring to  FIG. 16 , an exemplary gutter-cleaning device is shown in a cutaway view so that the internal elements are exposed. In this example, the gutter-cleaning device may comprise a spiral stiff bristle brush impeller  808 , a chute  110 , a placement facility  174 , a wheel  172 , a tractor tread  502 , and the like. 
     Referring to  FIG. 17 , an exemplary gutter-cleaning device is shown in a cutaway view so that the internal elements are exposed. In this embodiment, the gutter cleaning device  1700  has a perimeter internal gear disposed in the impeller  1702 , and a corresponding spur gear  1714  attached to a transfer/drive shaft  1722  and impeller gear box  1728  which rotate one or more impellers  1702 . The impeller  1702  has a bearing  1708  which attaches to a stationary impeller axle  1710 , allowing the impeller  1702  to freely rotate about a central axis. As the impeller  1702  rotates, a vane  1704  on the impeller  1702  may enable to removal of debris from a gutter. An impeller motor  1724  may drive the spur gear  1714  and may be powered by a battery  1730 . The gutter cleaning device  1700  may transport itself along a gutter. A tractor motor  1752  may drive a driven axle  1748  through a transport gear box  1750 . One or more gear wheels  1742  may be attached to the driven axle  1748 . One or more additional gear wheels  1744  may enable transport of the device  1700  but may be attached to a driven axle or may simply be free-wheeling. The gear wheels  1742 ,  1744  may engage a drive block  1740  on an inside surface of a caterpillar drive tread  1734 . The caterpillar drive tread  1734  may have fins  1738  that enable traction on a gutter surface. The impellers  1702  may have a nosecap  1720  held on by a clip  1718 . In embodiments, the nosecap  1720  may be a transparent lens for a vision system  124 . Wiring for the vision system  124  may be from the nosecap  1720 , through the stationary impeller axle  1710 , and to a motor control and communication circuit board  1732 . 
     Referring to  FIG. 18 , a transport drive motor  154  is depicted. 
     In an embodiment, the gutter-cleaning device  104  may comprise on-board tools or attachments  120 . The on-board tool  120  may be a downspout cleaning tool. When the device  104  reaches a downspout, it may deploy a cleaning tool, such as a weighted brush, into the downspout to clear it of debris. The cleaning tool  120  may run the length of the downspout and may be collected at the base of the downspout. In an embodiment, the tool  120  may be magnetic such that should the tool  120  get stuck in the downspout, it may be removed by dragging it down the spout using a magnetic force from the outside of the downspout. The device  104  may be directed to deploy the tool  120  by a remote control  168 , through programming, through detection of the downspout using a vision system  142  or some other detection mechanism, and the like. 
     Referring to  FIG. 27 , the cleaning tool  120  may be a downspout dervish cleaning robot. The downspout dervish may have a hemispherical structure. The dervish may comprise an internal motor and geartrain. The motor may be high torque to power the rotation of the hemispheres. The hemispheres of the dervish may rotate independently. The hemispheres may counter-rotate. The hemispheres may comprise vanes along the outside of the hemisphere for cleaning The vanes may be flexible, aggressive, similar to any of the impeller vanes described herein, any combination thereof, and the like. The vanes on the dervish may work similarly to the impeller vanes in their ability to lift and remove debris. The dervish may separate to allow for replacement or recharging of batteries, exchange of vanes, and the like. Once activated, a user may deploy the dervish at the top of a downspout. The dervish may be sized to fit in the downspout such that the vanes may effectively clean the downspout when the hemispheres may be rotated. The dervish may continue to rotate while it traverses and cleans the inside of the downspout. In an embodiment, the downspout dervish may be deployed independently of the device  104  or may be deployed by the device  104 . The dervish may have a power switch or may be remotely controlled. 
     In embodiments, the downspout cleaning tool may be an impeller  108  that may be oriented vertically to clean at least a top portion of the downspout. The impeller  108  may be present within the housing  152  and may emerge when directed to do so by a remote control  168 , through programming, through detection of the downspout using a vision system  142  or some other detection mechanism, and the like. In an alternative embodiment, the impeller may re-orient itself from the usual horizontal position at the end of the device  104  to a vertical position in order to clean the top portion of the downspout. 
     Referring to  FIG. 28 , the cleaning tool  120  may be a downspout inchworm cleaning robot. The downspout inchworm may comprise expandable upper and lower grippers which may be actuated. The grippers may be actuated by compressed air from a carbon dioxide cartridge, which may be disposed within the inchworm or may be located at a distance from the inchworm and may provide pressure remotely through a tube, or some other threaded compression drive to squeeze a bladder to cause the grippers to expand and secure the inchworm along the downspout. In an embodiment, each gripper may be actuated independently. In an alternative embodiment, a mechanical expansion system may be employed to expand the grippers, such as sliding ramps, a scissor action, and the like. A bellows disposed between the upper and lower gripper may be driven by a lead screw or other similar system to expand and contract and move the inchworm along the downspout. The bellows may comprise the motors, electronics, batteries and the like to drive the impeller or other motions. An impeller disposed at the top of the inchworm may rotate to clean clogged leaves and debris from the downspout. In an embodiment, the inchworm may operate in steps. A user may activate the inchworm and place it at the base of a downspout. First, the lower gripper may expand to anchor the inchworm to the downspout wall. Second, the bellows section may extend to an elongated position from the lower gripper. The bellows section may elongate to its longest possible length or any intervening length. Third, the upper gripper may expand to hold the wall. The lower gripper may then collapse or otherwise contract to let go of the wall. Fourth, the bellows section may contract by pulling the lower gripper up towards the upper gripper. During any step of this process or throughout the entire process, the impeller may be active. The motion of the inchworm and/or the impeller action may be remotely controlled or controlled by a power switch. As can be appreciated, the downspout inchworm may also be used to go down a downspout or traverse across a gutter. In embodiments, the inchworm may have impellers on both ends. In an embodiment, the inchworm may move in either direction. 
     In an embodiment, the on-board tool  120  may be an air hose attachment. The air hose attachment may attach on one end to an air compressor and on the other end to an impeller  108 , an impeller hub  118 , the housing  152 , the debris tines  112 , and the like. Air discharged through the air hose attachment may facilitate loosening and removal of debris. 
     In an embodiment, the on-board tool  120  may be a water hose attachment. The air hose attachment may attach on one end to a pressurized water supply and on the other end to an impeller  108 , an impeller hub  118 , the housing  152 , the debris tines  112 , and the like. Water discharged through the water hose attachment may facilitate loosening and removal of debris. 
     In an embodiment, the on-board tool  120  may be a weed whacker attachment. The weed whacker attachment my replace an impeller  108  on the gutter-cleaning device  104 . 
     In embodiments, the gutter-cleaning device  104  may be useful for residential gutter cleaning, professional gutter cleaning, as a gardening tool, pipe inspection and clearance, such as oil pipes, plumbing pipes, sewer pipes, water pipes, nuclear power plant pipes, as a dusting tool when the impeller may be formed from electrostatic cloth, and the like. 
     Referring now to  FIG. 29  and  FIG. 29A , an apparatus  2900  for cleaning a gutter may include a housing  2902 ; a transport drive  2904 ; an impeller  2908 ; an impeller drive facility  2910 ; a blade  2912 ; a rotating joint  2914 ; and a bearing  2918 . 
     The apparatus  2900  may be or include one or more elements of the gutter cleaning system  102 . The apparatus  2900  may be designed to fit substantially within a gutter  2920  and to clear debris out of the gutter. Transport of the apparatus  2900  within a debris-filled gutter may drive the impeller  2908  into and/or under debris. Rotation of the impeller  2908  may then fling the debris out of the gutter  2920 . It will be understood that various configurations and/or embodiments of the apparatus  2900  are possible. 
     The housing  2902  may be the housing  152  or the like. The housing  2902  may be a structural element that connects and/or contains the transport facility  2904  and the impeller drive facility  2910 . The housing  2902  may be rigid, articulated, flexible, any and all combinations of the foregoing, and so on. The housing  2902  may be constructed of any and all materials, including without limitation wood, metal, plastic, rubber, and so on. The housing  2902  may be adapted to fit within a gutter. The housing  2902  may be adapted to travel within a gutter. It will be understood that numerous embodiments of the housing  2902  are possible. 
     The transport drive  2904  may be the transport drive  154  or the like. The transport drive may be connected to the housing  2902 . The transport drive  2904  may include one or more treads, wheels, or the like connected to one or more motors. The transport drive  1904  may be adapted to transport the apparatus  2900  through the gutter. In particular, transport of the housing  2902  through the gutter  2920  may cause the impeller to travel along an axis of motion. The axis of motion may be substantially tangential to the gutter&#39;s  2920  centerline at the impeller  2908 . It will be understood that numerous embodiments of the transport drive  2904  are possible. 
     The impeller  2908  may be the impeller  108  or the like. The impeller may be connected to the impeller drive facility  2910 . The impeller  2908  may include helical vanes  2922  that pull debris back onto the blade  2912  as the impeller  2908  rotates. The impeller  2908  may have an axis of rotation  2922 . The impeller may be tapered to a tip or nose on one end and connected to the impeller drive facility  2910  on the other end. Both of the ends may lie substantially along the axis of rotation. 
     The axis of rotation  2922  may be oriented so that the tip or nose is angled toward the gutter&#39;s inside corner. As a result, when the housing  2902  is transported in the direction of the tip or nose, the impeller  2908  may tend to wedge under debris in the gutter  2920 . Such wedging may be desirable because it tends to prevent the apparatus  2900  from climbing up the debris as the apparatus  2900  moves. Moreover, angling the axis of rotation  2922  may provide some relief from overturning torque that could otherwise spin the apparatus  2900 , disengaging the transport drive  2904  from the gutter&#39;s  2920  surface. Furthermore, angling the axis of rotation  2922  may cause debris to be ejected from the gutter away and ahead of the impeller  2908 . This may allow a user to stand substantially abeam the apparatus  2900  while remaining clear of the debris&#39; trajectory. 
     The impeller drive facility  2910  may be the impeller drive facility  138  or the like. The impeller drive facility  2910  may be connected to the housing  2902 . The impeller drive facility may consist of a motor adapted to rotate the impeller  2908  on the axis of rotation  2922 . It will be understood that numerous embodiments of the impeller drive facility  2910  are possible. 
     The blade  2912  may be the alternating flexible blade  818 , the vane  702 , or the like. The blade  2912  may be connected to or part of the impeller  2908 . The blade  2912  may be flexible. The blade  2912  may extend past the rotating joint  2912  (for example, as shown at  2924 ). This may inhibit debris from wrapping around an axle or the like that connects the impeller  2908  to the impeller drive facility  2910 . The blade  2912  may be adapted both to deflect when brought into contact with the gutter  2920  and to release when brought out of contact with the gutter  2920 . Thus, as the impeller  2908  rotates the blade  2912  may repeatedly deflect and then release. First, deflection of the blade  2912  combined with rotation of the impeller  2908  may tend to push the blade  2912  substantially underneath debris in the gutter. Then, continued rotation of the impeller  2908  combined with release of the blade  2912  may tend to scoop and eject debris from the gutter  2920 . 
     The rotating joint  2914  may be a joint between the impeller  2908  and the housing  2902 . At the rotating joint  2914  the impeller  2908  may rotate with respect to the housing  2902 . 
     The bearing  2918  may be substantially spherical and may be disposed at the impeller&#39;s  2908  nose or tip. The bearing  2918  may provide freedom for both rotational and translational movement of the nose or tip along the gutter  2920 . The bearing  2918  may be composed of any and all suitable materials, including without limitation metal, plastic, rubber, or the like. It will be understood that many embodiments of the bearing  2918  are possible. 
     Referring now to  FIG. 30 , an apparatus  3000  for cleaning a gutter may include the housing  2902 ; transport drive  2904 ; the impeller drive facility  2910 ; a circuit  3002 ; a second impeller drive facility  3008 . In this depiction, the housing  2902  and viewer-facing surfaces of some elements may be substantially transparent for the purpose of revealing inner elements of the apparatus  3000 . 
     The apparatus  3000  may be the apparatus  2900 , one or more elements of the gutter cleaning system  102 , or the like. 
     In applications, as the impeller  2908  rotates, the impeller  2908  may eject debris from a gutter. 
     From time to time, the impeller&#39;s  2908  rotation  3010  may be impeded due to heavy, dense debris or the like. Unable to rotate the impeller  2908 , the torque of the impeller drive facility  2910  may be transferred to the housing  2902 , causing the housing  2902  to begin rotating  3012 . 
     From time to time, the impeller  2908  may climb up the debris instead of ejecting it. This may cause the transport drive  2904  to become underweighted as the impeller  2908  begins supporting some of the apparatus&#39;  3000  mass. Here, a reaction force  3020  of the impeller drive facility&#39;s  2910  torque may begin to rotate  3012  the housing  2902 . 
     If left unchecked, rotating  3012  the housing  2902  may overturn the apparatus  3000 , causing the transport drive  2904  to disengage from the gutter&#39;s surface. This may leave the apparatus  3000  in an inoperable state (that is, a state in which the apparatus  3000  can no longer transport itself). 
     The following may describe how the apparatus  3000  avoids overturn by detecting and reacting to longitudinal rotations  3012  of the housing  2902 . 
     The circuit  3002  may include an electrical circuit consisting of any and all number of electronic components. The circuit  3002  may be disposed inside the housing  2902  and operatively coupled to the impeller drive facility  2910 . Such operative coupling may include an electrical or electromagnetic coupling. 
     The circuit  3002  may detect the housing&#39;s  2902  rotation about the apparatus&#39;  3000  longitudinal axis. At least one of the electronic components of the circuit  3002  may be a sensor  3018  can detect this rotation. The sensor  3018  may be an accelerometer, a gyroscope, or the like. It will be understood that various embodiments of the sensor are possible. 
     In response to detecting the housing&#39;s  2902  rotation and/or a trend in the housing&#39;s  2902  rotation, the circuit  3002  may communicate a control signal to the impeller drive facility  2910 . Electronic components of the circuit  3002  may include any and all number of microprocessors, logic devices, analog components, combinations of the foregoing, or the like that together communicate the control signal. It will be understood that various embodiments and combinations of these electronic components are possible. 
     The control signal may be directed at reducing, reversing, or otherwise modifying a torque produced by the impeller drive facility  2910 . This may reduce, halt, or correct  3014  the housing&#39;s  2902  rotation  3012  and/or rate of rotation. The control signal may include a digital command signal, a stepping-motor actuation signal, an analog signal, or the like. It will be understood that various embodiments of the control signal are possible. 
     The second impeller drive facility  3008  may be substantially like or identical to the impeller drive facility  2910 . The second impeller drive facility  3008  may be operatively coupled to the circuit  3002 . 
     In response to detecting the apparatus&#39;  3000  rotation, the circuit may communicate a second control signal to the second impeller drive facility  3008 . The second control signal  3010  may be akin to the control signal  3004 . 
     The circuit may more or less simultaneously communicate the control signal and the second control signal. This may allow coordinated modification of the torques produced by the impeller drive facilities  2910 ,  3008 . Such coordinated modification of the torques may reduce, halt, or correct  3014  the housing&#39;s  2902  rotation  3012  and/or rate of rotation. 
     The elements depicted in flow charts and block diagrams throughout the figures imply logical boundaries between the elements. However, according to software or hardware engineering practices, the depicted elements and the functions thereof may be implemented as parts of a monolithic software structure, as standalone software modules, or as modules that employ external routines, code, services, and so forth, or any combination of these, and all such implementations are within the scope of the present disclosure. Thus, while the foregoing drawings and description set forth functional aspects of the disclosed systems, no particular arrangement of software for implementing these functional aspects should be inferred from these descriptions unless explicitly stated or otherwise clear from the context. 
     Similarly, it will be appreciated that the various steps identified and described above may be varied, and that the order of steps may be adapted to particular applications of the techniques disclosed herein. All such variations and modifications are intended to fall within the scope of this disclosure. As such, the depiction and/or description of an order for various steps should not be understood to require a particular order of execution for those steps, unless required by a particular application, or explicitly stated or otherwise clear from the context. 
     The methods or processes described above, and steps thereof, may be realized in hardware, software, or any combination of these suitable for a particular application. The hardware may include a general-purpose computer and/or dedicated computing device. The processes may be realized in one or more microprocessors, microcontrollers, embedded microcontrollers, programmable digital signal processors or other programmable device, along with internal and/or external memory. The processes may also, or instead, be embodied in an application specific integrated circuit, a programmable gate array, programmable array logic, or any other device or combination of devices that may be configured to process electronic signals. It will further be appreciated that one or more of the processes may be realized as computer executable code created using a structured programming language such as C, an object oriented programming language such as C++, or any other high-level or low-level programming language (including assembly languages, hardware description languages, and database programming languages and technologies) that may be stored, compiled or interpreted to run on one of the above devices, as well as heterogeneous combinations of processors, processor architectures, or combinations of different hardware and software. 
     Thus, in one aspect, each method described above and combinations thereof may be embodied in computer executable code that, when executing on one or more computing devices, performs the steps thereof. In another aspect, the methods may be embodied in systems that perform the steps thereof, and may be distributed across devices in a number of ways, or all of the functionality may be integrated into a dedicated, standalone device or other hardware. In another aspect, means for performing the steps associated with the processes described above may include any of the hardware and/or software described above. All such permutations and combinations are intended to fall within the scope of the present disclosure. 
     While the invention has been disclosed in connection with the preferred embodiments shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is not to be limited by the foregoing examples, but is to be understood in the broadest sense allowable by law. 
     All documents referenced herein are hereby incorporated by reference. 
     A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.