Railcar cleaning apparatus

Information

  • Patent Grant
  • 6317919
  • Patent Number
    6,317,919
  • Date Filed
    Friday, July 14, 2000
    24 years ago
  • Date Issued
    Tuesday, November 20, 2001
    23 years ago
Abstract
A mobile vacuum cleaner for removing particulate materials from a chamber of a railcar or container is mounted on a motor truck operable to locate the vacuum cleaner adjacent a railcar. The cleaner has a material pick-up hose connected to a box and a motor driven fan for drawing air through the hose and box to pick up particulate materials from the chamber of the railcar and transport the particulate materials to the box. A lift device mounted on the truck has articulated booms and a work person carrier that can be located in the chamber of the railcar allowing the work person to move the hose adjacent the particulate material in the chamber and visually observe the cleaning operation.
Description




FIELD OF THE INVENTION




The invention is in the field of mobile equipment for cleaning bulk and particulate materials from railcars, truck trailers, and containers. The mobile equipment includes a motor vehicle or truck having a vacuum cleaning apparatus and a lift device for moving a work person carrier and work person on the carrier to a location within the chamber of the railcar or container to enable the work person to control the location of a vacuum hose to pick up particulate materials in the chamber.




BACKGROUND OF THE INVENTION




Mobile pneumatic granular material conveying systems are used to unload and transport granular materials from vehicles, such as railcars, barges, and ship holds, to storage silos and factories. G.V. Aalst in U.S. Pat. No. 4,659,262 describes such a mobile pneumatic granular material conveying system having an articulated vacuum arm supporting a hose for carrying material from an intake nozzle to a material storage tank. An operator located near the material storage structure uses a remote control device to position the vacuum arm to locate the nozzle in the material so that the material is drawn into the hose and transported to a storage tank. A vacuum machine and boom mounted on a motor truck is disclosed by H.J. Davis in U.S. Pat. No. 5,142,732. The boom supports a material pick up hose and a bulk material separator operable to remove heavy bulk materials without materially reducing the vacuum in the hose. These vacuum conveying and boom structures do not allow the work person to be positioned in the chamber or space being cleaned during the cleaning process. The work person is not in a position that allows for visual inspection of the chamber and movement of the material pick up hose to a location to effectively and efficiently remove particulate materials from the chamber of a railcar or container. Railcars have bottom gates that allow the bulk load carried by the railcar to be unload by allowing the load to flow down. Residual load or particulate materials adhere to the walls of the railcar or remain in the chamber of the railcar. The residual particulate material are removed from the chamber of the railcar with the vacuum cleaning apparatus of the invention.




SUMMARY OF THE INVENTION




The invention is a method and an apparatus for cleaning chambers and spaces of railcars, truck trailers, containers, and structures for accommodating bulk or particulate materials, such as grain, sand, plastic pellets, ore and fly ash. The work person has direct visual inspection and control of the cleaning operation to efficiently and effectively remove particulate materials from the chambers. A motor truck is used to transport a vacuum cleaner and movable lift device supporting a work person carrier, such as a basket used to support a work person. The truck is driven to a location adjacent an open top railcar, truck trailer, or container having a chamber with residual particulate materials. The vacuum cleaner has an elongated hose that is extended into the chamber. The hose has an air inlet opening which allows particulate material to be drawn into the hose and transported to a box used to store the particulate materials. The lift device is operable to position the work person carrier and work person thereon within the chamber to allow the work person to visually locate and manipulate the position of the hose and it's air inlet opening adjacent the particulate material so that the particulate material is drawn into the hose. This allows the work person to clean the railcar chamber in minimum time and will reduce labor.




The vacuum cleaner has a box or housing with an enclosed internal chamber coupled to a motor driven fan. The fan operates to draw air from the chamber of the bin and move air through air inlet opening and hose to transport particulate materials to the bin. The lift device has a stand mounted on the truck. A first or main boom pivotally connected to the stand is selectively raised and lowered with a first hydraulic cylinder. A second boom is pivotally connected to the outer or remote end of the main boom. A second hydraulic cylinder is pivotally connected to the main boom and a toggle linkage. The toggle linkage has pairs of links pivotally connected to the first and second booms. The second cylinder operates to move the toggle linkage to a folded position to move the second boom to an extended position relative to the first boom. When the second cylinder is elongated the toggle linkage is extended and moves the second boom to a folded storage position adjacent a side of the first boom. The work person on the work person carrier located in the chamber of the railcar operates controls mounted on the second boom to actuate the first and second cylinders and a turntable operable to swing the left device about an upright axis. The work person operates the controls to change the up, down, and lateral locations of the work person carrier. The work person on the carrier manipulates the hose to clear the chamber of the railcar or container of particulate material and visually observe the cleaning of the chamber. The hose can be attached to the second boom or work person carrier to permit the movement of the second boom to change the location of the hose relative to the chamber of the railcar.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side elevational view of a vacuum railcar cleaner truck having an articulated lift device and a work person carrier constructed in accordance with the present invention;





FIG. 2

is a top plan view of the truck, lift booms, and work person carrier of

FIG. 1

;





FIG. 3

is a side elevational view of the articulated booms of the lift device and work showing the booms in folded positions;





FIG. 4

is a top plan view of the outer ends of the booms of

FIG. 3

;





FIG. 5

is a side elevational view of the articulated booms in extended position with the work person carrier located within the load chamber of an open top railcar; and





FIG. 6

is a top plan view of the vacuum railcar cleaner truck and open top railcar showing the method of cleaning the railcar.











DESCRIPTION OF PREFERRED EMBODIMENT OF VACUUM RAILCAR CLEANER




The vacuum railcar cleaner


10


, shown in

FIGS. 1

,


2


, and


6


, is used to efficiently clean gondolas or open top rail cars


1


that transport particulate materials, such as grain, sand, coal, plastic beads, fly ash and taconite ore. Cleaner


10


is operable to clean other structures, such as open top tanks and containers, truck trailers, barges, rooms, and ship holds. The following description is directed to the cleaning of particulate materials from open top railcars. The cleaner


10


comprises mobile equipment that is moved to the location of the railcars and used to clean the inside of the railcars of residual load herein termed particulate materials. The railcars remain coupled as the equipment is moveable along a line of railcars or to selected railcars in a train of cars.




Railcar cleaner


10


has a conventional motor truck or lorry


12


which includes an elongated longitudinal frame


13


supported on a roadway or ground surface with front steering wheels


14


and rear drive wheels


16


. An operator's cab


17


mounted on frame


13


is located behind hood


18


. An internal combustion engine (not shown) is located below hood


18


.




A rectangular shaped tank or box


19


is mounted on frame


13


above drive wheels


16


. Box


19


has an enclosed internal chamber for collecting and holding the particulate materials picked up from the load chamber of the railcar. An air and material inlet tube or nipple


21


mounted on a side of box


19


is attached to an elongated flexible hose


22


having a nozzle


23


at it's forward or distal end. Hose


22


has sufficient length to extend from box


19


over a side of railcar


11


and into the load carrying chamber


33


of the railcar


11


. Nozzle


22


has a cone shape that converges to its inlet opening. Air rapidly flowing through the inlet opening of nozzle


23


draws particulate materials in the bottoms of railcar chamber


11


into hose


22


. The particulate materials are discharged from hose


22


into collection box


19


. Box


19


has a bottom gate (not shown) to allow the collected materials to flow out the box. The interior of box


19


has baffles that restrict movement of particulate materials and allow the particulate material to settle or separate from the flowing air. Other structures, such as doors, can be used to allow the collected materials to be removed from box


19


. The dust and air entrained particulate materials in the interior of box


19


are spayed with water which collects the dust. As shown in

FIG. 1

, a water pump


83


mounted on frame


13


adjacent motor control


30


discharges water under pressure into a line


84


connected to a nozzle


86


. Nozzle


86


mounted on top of box


19


directs a spray of water into box chamber


87


to control the dust in the chamber. One or more nozzles can be used to dispense sprays of water into chamber


87


.




A fan or air mover


24


mounted on frame


13


operates to draw air from the inside of box


19


and generate air suction pressure on air drawn into nozzle


23


and flowing in hose


22


. An air inlet housing


25


connects fan


24


with the front wall of box


19


whereby air in box


19


flows into fan


24


as shown by arrow


26


. Air is discharged upwardly from fan


24


, shown by arrow


27


in

FIG. 1

, into an air filter


28


mounted on top of fan


24


. Filter


28


removes dirt and dust from the air which is discharged into the environment. An internal combustion engine


29


mounted on frame


13


is drivably connected to fan


24


. The speed of engine


29


is adjusted to change the suction pressure of air in hose


22


and box


19


. A motor control


30


mounted on frame


13


is used by the work person to regulate the speed of engine


29


.




The cleaner


10


has a lift device or crane, indicated generally at


31


, for supporting and moving a work person carrier, shown as a basket or bucket


32


to a desired location. Carrier


32


, as shown in

FIGS. 5 and 6

, can be placed in railcar load chamber


33


so that a work person


34


can control the position of nozzle


23


in chamber


33


to pick up material from the bottom and sides of chamber


33


and visually observe the cleaning of the chamber


33


.




Lift device


31


is secured to a platform


36


mounted on frame


13


between cab


17


and engine


29


. Lift device


31


has a support comprising a mounting plate


37


and posts


38


securing plate


37


to platform


36


. A turntable


39


located above plate


37


with a standard or support members


41


is operate to allow carrier


32


to be moved in a circular path around a vertical axis, shown at


42


in

FIG. 2. A

hydraulic or electric motor (not shown) is used to drive turntable


39


. Other structures can be used to turn lift device


31


in an arcuate path relative to a vertical axis.




A U-shaped member


43


mounted on a post


44


connected to turntable


39


is pivotally connected to a main boom


46


with pivot member or bolt


47


. Boom


46


is an elongated linear square metal tube. Boom


46


can have other shapes, such as cylindrical. A hydraulic cylinder


48


connected with a pivot bolt


49


to U-shaped member


43


has a piston rod


51


connected with a pivot bolt


52


to ears


53


secured to the bottom of boom


46


. Cylinder


48


functions to selectively raise and lower boom


46


as shown in

FIGS. 1

,


3


, and


5


.




As shown in

FIGS. 3 and 4

, an elongated linear secondary boom


54


located adjacent a side of boom


46


is joined to the outer end of boom


54


with a connecting member


56


. Member


56


is a box-like housing having a pair of arms


57


and


58


extended adjacent opposite sides of the outer end of boom


46


. A pivot pin or bolt


59


pivotally connects arms


57


and


58


to boom


46


. Pivot bolts


47


and


59


are located in parallel transverse axes relative to the length of boom


46


. The inner or proximal end of boom


54


extends into member


56


and is secured thereto with welds.




A hydraulic cylinder


62


pivots boom


54


between a folded storage position, shown in

FIGS. 3 and 4

, and a raised or extended position, shown in

FIGS. 1

,


5


, and


6


. Cylinder


62


has a double acting piston connected to a piston rod


63


. Cylinder


62


has an end located between a pair of ears


64


and


66


secured to a middle portion of boom


46


. A transverse pivot pin or bolt


67


pivotally connects cylinder


62


to ears


64


and


66


. Piston rod


63


has an outer end connected to a transverse head


68


accommodating a pivot pin or bolt


69


. Bolt


69


connects a toggle linkage


71


pivotally connected to boom


46


and member


56


to control movement of boom


54


without damage to cylinder


62


. Toggle linkage


71


is a control linkage comprising a first toggle links


72


and


73


and second toggle links


74


and


76


. Pivot bolt


69


pivotally connects adjacent ends of links


72


,


73


, and


74


,


76


. A transverse pivot pin or bolt


77


pivotally connects links


72


and


74


to opposite sides of boom


46


inwardly from bolt


59


. Another pivot pin or bolt


78


pivotally connects links


73


and


76


to member


56


and arm


57


, as shown in FIG.


4


. Bolt


78


is located above pivot bolt


59


so that when cylinder


62


is retracted toggle linkage


71


folds, as shown in

FIGS. 1 and 5

, and pivots boom


54


about the transverse axis of pivot bolt


59


to swing boom


54


to an extended position. The angular position of boom


54


relative to boom


46


can be changed since cylinder


62


can swing boom


54


about


120


degrees around the axis of pivot bolt


59


without damaging cylinder


62


.




Work person carrier


32


is a plastic casing having an open top providing confined support for work person


34


. A transverse connector


79


joins carrier


32


to the outer end of boom


54


. Carrier


32


is free to pivot on connector


79


to retain the carrier in its upright position regardless of the angular position of boom


54


. The control valves and levers


81


for controlling the flow of hydraulic fluid to and from cylinders


48


and


62


are mounted on boom


54


adjacent carrier


32


in a location where they can be used by the work person


34


to change the position of carrier


32


between platform


36


and chamber


33


of railcar


11


. Turntable


39


is also controlled with control valves and levers


81


to move carrier


32


in an arcuate path


42


relative to a vertical axis.




A plurality of electric lights


82


mounted on boom


54


provide luminous energy into railcar


11


that enables work person


34


to visually observe the load chamber


33


and particulate materials


83


in the chamber at night or on cloudy days. The area encompassed by the light can be changed by moving either boom


46


or boom


54


.




In use to clean the load chamber of a railcar


11


of residual particulate materials, the truck


12


having the vacuum cleaner equipment and lift device


31


is driven to a location adjacent the side of railcar


11


, as shown in FIG.


6


. The work person


34


climbs onto platform


36


adjacent carrier


32


located on the platform. When booms


46


and


54


are in the folded storage positions, shown in

FIG. 3

, carrier


32


is on platform


36


. The work person


34


manipulates levers


81


to actuate cylinder


48


to selectively pivot boom


46


in upward and downward directions. Cylinder


48


is operable to move boom


46


about pivot bolts


47


about


90


degrees or between a generally horizontal position to a generally vertical position. When boom


46


is moved to a selected position, hydraulic fluid to and from cylinder


48


is blocked whereby cylinder


48


holds boom


46


in the selected position. Turntable


39


is actuated to swing booms


46


and


54


to move basket


32


off of platform


36


and allow carrier


32


to clear engine


29


. Hydraulic cylinder


62


is then actuated to fold toggle linkage


71


and pivot boom


54


away from boom


46


in a counterclockwise direction. Toggle linkage


71


and cylinders


48


and


62


allows carrier


32


to be moved below ground level into pit or above ground into chamber


33


of railcar


11


. Turntable


39


is operated to swing boom


54


and carrier


32


over the side of railcar


11


. Hydraulic cylinder


62


is then expanded to lower carrier


32


and work person


34


into chamber


33


of railcar


11


. Work person


34


is in a position to handle hose


22


and locate nozzle


23


adjacent particulate material


83


and at locations containing additional particulate materials. Hose


22


can be attached to boom


54


or carrier


32


with a connector


55


, shown in

FIG. 6

, to allow hydraulic cylinders


48


and


62


to be used to change the location of hose and nozzle


23


in chamber


33


. When chamber


33


is clean cylinder


48


is extended to raise boom


54


and carrier


32


and work person out of chamber


33


. Turn table


39


is actuated to swing booms


46


and


54


and carrier


32


over truck


12


. Boom


54


is returned to the folded position, adjacent boom


46


by extending cylinder


62


to expand toggle linkage


71


. Main boom


46


is then returned to a horizontal position by contracting cylinder


48


. The lift device


31


is in the transport position as shown in FIG.


3


.




The vacuum cleaner vehicle


12


has been described as an apparatus and method for vacuum cleaning an open top railcar. Vehicle


12


can be used to clean tanks, containers, and rooms that have open tops or doors allowing entrance into the interior chambers thereof. The vehicle


12


has a self contained vacuum cleaning system and work person lift device. Changes in the structure and arrangement of structures of the cleaning system and lift device can be made by a person skilled in the art without departing from the method and apparatus of the invention. The invention is defined in the following claims.



Claims
  • 1. An apparatus for cleaning particulate materials from a chamber of an open top container comprising:a motor truck, vacuum cleaner means mounted on the truck for collecting and storing particulate materials, said vacuum cleaner means having an enclosed particulate material collection box, an elongated hose connected to the box for carrying particulate materials to the box, said hose having an end with an air inlet opening, a fan for drawing air from the box and moving air through the air inlet opening and hose into the box, said air flowing into the inlet opening picking up particulate materials and said air moving in the hose transporting the particulate materials to the box, power means for driving the fan, a lift device mounted on the truck, a work person carrier connected to the lift device, said lift device having boom means movably mounted on the truck supporting the work person carrier and locating the work person carrier in the chamber of the container, and means connected to the boom means for moving the boom means to locate the work person carrier in the chamber of the container.
  • 2. The apparatus of claim 1 wherein: the container is an open top railcar having a chamber for holding particulate materials.
  • 3. The apparatus of claim 1 wherein: the work person carrier is a basket pivotally mounted on a remote end portion of the boom means.
  • 4. The apparatus of claim 1 wherein: the boom means comprises a first boom and a second boom, pivot means pivotally connecting the first boom to the second boom, a hydraulic cylinder for moving the second boom relative to the first boom, toggle linkage means for controlling the movement of the second boom, and means pivotally connecting the toggle linkage means to the first and second booms and hydraulic cylinder whereby on actuation of the hydraulic cylinder the toggle linkage means selectively folds and expands to move the second boom relative to the first boom.
  • 5. The apparatus of claim 4 wherein: the toggle linkage means comprises a pair of toggle links, each toggle link having a first member pivotally connected to the first boom, a second member pivotally connected to the second boom, and pivot means pivotally connecting the first and second members and the hydraulic cylinder to the first and second members.
  • 6. The apparatus of claim 4 including: means for pivotally connecting the work person carrier to an outer end portion of the second boom, and means for connecting the hose to the work person carrier.
  • 7. The apparatus of claim 4 wherein: the lift device has a support mounted on the truck, means pivotally connecting the support to the first boom, a hydraulic cylinder connected to the support and first boom operable to raise and lower the first boom.
  • 8. The apparatus of claim 7 wherein: the lift device includes means for turning the first and second booms about a vertical axis.
  • 9. The apparatus of claim 1 wherein: the lift device has a support mounted on the truck, means pivotally connecting the boom means to the support, and a first hydraulic cylinder connected to the support and boom means operable to raise and lower the boom means.
  • 10. The apparatus of claim 9 wherein: the boom means comprises a first boom and a second boom, pivot means pivotally connecting the first boom to the second boom, a second hydraulic cylinder for moving the second boom relative to the first boom, toggle linkage means for controlling the movement of the second boom, and means pivotally connecting the toggle linkage means to the first and second booms and second cylinder whereby on actuation of the second cylinder the toggle linkage means selectively folds and expands to move the second boom relative to the first boom.
  • 11. The apparatus of claim 10 wherein: the toggle linkage means comprises a pair of toggle links, each toggle link having a first member pivotally connected to the first boom, a second member pivotally connected to the second boom, and pivot means pivotally connecting the first and second members and the second cylinder to the first and second members.
  • 12. The apparatus of claim 10 including: means for pivotally connecting the work person carrier to an outer end portion of the second boom, and means for connecting the hose to the work person carrier.
  • 13. The apparatus of claim 1 wherein: said boom means comprises a first boom having an inner end and an outer end, a second boom having an inner end and an outer end, a member secured to the inner end of the second boom extended over a portion of the outer end of the first boom, arm means secured to the member extended toward the outer end of the first boom spacing the member from the outer end of the first boom, pivot means connecting the arm means to the outer end of the first boom, toggle linkage means pivotally connected to the member and outer end of the first boom for controlling the movement of the second boom, said means connected to the boom means comprising a first extendable and contractable means connected to the first boom operable to swing the first boom between up and down positions, and a second extendable and contractable means connected to the first boom and toggle linkage means operable to selectively fold and expand the toggle linkage means to pivot the second boom relative to the first boom and locate the outer end of the second boom in the chamber, and means mounting the work person carrier on the outer end of the second boom whereby a work person positioned in the work person carrier can be located in the chamber and move the end of the hose having the air inlet opening in the chamber to pick up particulate materials located in the chamber.
  • 14. An apparatus for cleaning particulate materials from a railcar having side and end walls surrounding a chamber for holding particulate materials and an open top comprising: a vehicle adapted to be moved to a location adjacent the railcar, vacuum cleaner means mounted on the vehicle for collecting and storing particulate materials, said vacuum cleaner means having an enclosed particulate material collection box, an elongated hose connected to the box for carrying particulate materials to the box, said hose having a remote end with an air inlet opening to allow air to move particulate materials into the hose, means for drawing air from the box and moving air through the air inlet opening and hose into the box, said air flowing into the air inlet opening picking up particulate materials from the chamber and the air flowing in the hose transporting the particulate materials to the box, a lift device mounted on the vehicle, a work person carrier, said lift device having a first boom having an inner end and an outer end, a second boom having an inner end and an outer end, a member secured to the inner end of the second boom extended over a portion of the outer end of the first boom, arm means secured to the member extended toward the outer end of the first boom spacing the member from the outer end of the first boom, pivot means connecting the arm means to the outer end of the first boom, toggle linkage means pivotally connected to the member and outer end of the first boom for controlling the movement of the second boom, a first hydraulic cylinder connected to the first boom operable to swing the first boom between up and down positions, a second hydraulic cylinder connected to the first boom and toggle linkage means operable to selectively fold and expand the toggle linkage means to pivot the second boom relative to the first boom and locate the outer end of the second boom in the chamber of the railcar, and means mounting the work person carrier on the outer end of the second boom whereby a work person positioned in the work person carrier can be located in the chamber of the railcar and move the remote end of the hose in the chamber to pick up particulate materials located in the chamber of the railcar.
  • 15. The apparatus of claim 14 wherein: the toggle linkage means comprises a pair of toggle links, each toggle link having a first member pivotally connected to the first boom, a second member pivotally connected to the member secured to the second boom, and pivot means pivotally connecting the first and second members and the hydraulic cylinder to the first and second members.
  • 16. The apparatus of claim 14 including: means for pivotally connecting the work person carrier to an outer end of the second boom and means for connecting the hose to the work person carrier.
  • 17. The apparatus of claim 14 wherein: the lift device has a support mounted on the truck, means pivotally connecting the support to the first boom, and said first hydraulic cylinder being connected to the support and first boom operable to raise and lower the first boom.
  • 18. The apparatus of claim 17 wherein: the lift device includes means for turning the first and second booms about a vertical axis.
  • 19. An apparatus for cleaning particulate materials from a chamber of an open top container comprising: a vehicle adapted to be moved to a location adjacent the container, vacuum cleaner means mounted on the vehicle for collecting and storing particulate materials, said vacuum cleaner means having an enclosed particulate material collection box, an elongated hose connected to the box for carrying particulate materials to the box, said hose having an end with an air inlet opening, means for drawing air from the box and moving air through the air inlet opening and hose into the box, said air moving in the hose transporting the particulate materials to the box, a lift device mounted on the vehicle, a work person carrier connected to the lift device, said lift device having boom means movably mounted on the vehicles means connected to the boom means for moving the boom means to locate the work person carrier in the chamber of the container, said boom means comprises a first boom having an inner end and an outer end, a second boom having an inner end and an outer end, a member secured to the inner end of the second boom extended over a portion of the outer end of the first boom, arm means secured to the member extended toward the outer end of the first boom spacing the member from the outer end of the first boom, pivot means connecting the arm means to the outer end of the first boom, toggle linkage means pivotally connected to the member and outer end of the first boom for controlling the movement of the second boom, said means connected to the boom means comprising a first extendable and contractable means connected to the first boom operable to swing the first boom between up and down positions, and a second extendable and contractable means connected to the first boom and toggle linkage means operable to selectively fold and expand the toggle linkage means to pivot the second boom relative to the first boom and locate the outer end of the second boom in the chamber, and means mounting the work person carrier on the outer end of the second boom whereby a work person positioned in the work person carrier can be located in the chamber and move the end of the hose having the air inlet opening in the chamber to pick up particulate materials located in the chamber.
  • 20. The apparatus of claim 19 wherein: the toggle linkage means comprises a pair of toggle links, each toggle link having a first member pivotally connected to the first boom, a second member pivotally connected to the second boom, and pivot means pivotally connecting the first and second members and the hydraulic cylinder to the first and second members.
  • 21. The apparatus of claim 19 including: means for pivotally connecting the work person carrier to an outer end of the second boom and means for connecting the hose to the work person carrier.
  • 22. The apparatus of claim 19 wherein: the lift device has a support mounted on the vehicle, means pivotally connecting the support to the first boom, and said first hydraulic cylinder being connected to the support and first boom operable to raise and lower the first boom.
  • 23. The apparatus of claim 22 wherein: the lift device includes means for turning the first and second booms about a vertical axis.
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 09/188,270 filed Nov. 9, 1998 application Ser. No. 09/188,270 claims the priority of U.S. Provisional Application Serial No. 60/105,479 filed Oct. 23, 1998.

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Provisional Applications (1)
Number Date Country
60/105479 Oct 1998 US